xref: /openbmc/linux/drivers/i2c/busses/i2c-stm32f7.c (revision 22a1f8a5)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver for STMicroelectronics STM32F7 I2C controller
4  *
5  * This I2C controller is described in the STM32F75xxx and STM32F74xxx Soc
6  * reference manual.
7  * Please see below a link to the documentation:
8  * http://www.st.com/resource/en/reference_manual/dm00124865.pdf
9  *
10  * Copyright (C) M'boumba Cedric Madianga 2017
11  * Copyright (C) STMicroelectronics 2017
12  * Author: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
13  *
14  * This driver is based on i2c-stm32f4.c
15  *
16  */
17 #include <linux/clk.h>
18 #include <linux/delay.h>
19 #include <linux/err.h>
20 #include <linux/i2c.h>
21 #include <linux/i2c-smbus.h>
22 #include <linux/interrupt.h>
23 #include <linux/io.h>
24 #include <linux/iopoll.h>
25 #include <linux/mfd/syscon.h>
26 #include <linux/module.h>
27 #include <linux/of.h>
28 #include <linux/of_address.h>
29 #include <linux/of_platform.h>
30 #include <linux/platform_device.h>
31 #include <linux/pinctrl/consumer.h>
32 #include <linux/pm_runtime.h>
33 #include <linux/pm_wakeirq.h>
34 #include <linux/regmap.h>
35 #include <linux/reset.h>
36 #include <linux/slab.h>
37 
38 #include "i2c-stm32.h"
39 
40 /* STM32F7 I2C registers */
41 #define STM32F7_I2C_CR1				0x00
42 #define STM32F7_I2C_CR2				0x04
43 #define STM32F7_I2C_OAR1			0x08
44 #define STM32F7_I2C_OAR2			0x0C
45 #define STM32F7_I2C_PECR			0x20
46 #define STM32F7_I2C_TIMINGR			0x10
47 #define STM32F7_I2C_ISR				0x18
48 #define STM32F7_I2C_ICR				0x1C
49 #define STM32F7_I2C_RXDR			0x24
50 #define STM32F7_I2C_TXDR			0x28
51 
52 /* STM32F7 I2C control 1 */
53 #define STM32F7_I2C_CR1_PECEN			BIT(23)
54 #define STM32F7_I2C_CR1_ALERTEN			BIT(22)
55 #define STM32F7_I2C_CR1_SMBHEN			BIT(20)
56 #define STM32F7_I2C_CR1_WUPEN			BIT(18)
57 #define STM32F7_I2C_CR1_SBC			BIT(16)
58 #define STM32F7_I2C_CR1_RXDMAEN			BIT(15)
59 #define STM32F7_I2C_CR1_TXDMAEN			BIT(14)
60 #define STM32F7_I2C_CR1_ANFOFF			BIT(12)
61 #define STM32F7_I2C_CR1_DNF_MASK		GENMASK(11, 8)
62 #define STM32F7_I2C_CR1_DNF(n)			(((n) & 0xf) << 8)
63 #define STM32F7_I2C_CR1_ERRIE			BIT(7)
64 #define STM32F7_I2C_CR1_TCIE			BIT(6)
65 #define STM32F7_I2C_CR1_STOPIE			BIT(5)
66 #define STM32F7_I2C_CR1_NACKIE			BIT(4)
67 #define STM32F7_I2C_CR1_ADDRIE			BIT(3)
68 #define STM32F7_I2C_CR1_RXIE			BIT(2)
69 #define STM32F7_I2C_CR1_TXIE			BIT(1)
70 #define STM32F7_I2C_CR1_PE			BIT(0)
71 #define STM32F7_I2C_ALL_IRQ_MASK		(STM32F7_I2C_CR1_ERRIE \
72 						| STM32F7_I2C_CR1_TCIE \
73 						| STM32F7_I2C_CR1_STOPIE \
74 						| STM32F7_I2C_CR1_NACKIE \
75 						| STM32F7_I2C_CR1_RXIE \
76 						| STM32F7_I2C_CR1_TXIE)
77 #define STM32F7_I2C_XFER_IRQ_MASK		(STM32F7_I2C_CR1_TCIE \
78 						| STM32F7_I2C_CR1_STOPIE \
79 						| STM32F7_I2C_CR1_NACKIE \
80 						| STM32F7_I2C_CR1_RXIE \
81 						| STM32F7_I2C_CR1_TXIE)
82 
83 /* STM32F7 I2C control 2 */
84 #define STM32F7_I2C_CR2_PECBYTE			BIT(26)
85 #define STM32F7_I2C_CR2_RELOAD			BIT(24)
86 #define STM32F7_I2C_CR2_NBYTES_MASK		GENMASK(23, 16)
87 #define STM32F7_I2C_CR2_NBYTES(n)		(((n) & 0xff) << 16)
88 #define STM32F7_I2C_CR2_NACK			BIT(15)
89 #define STM32F7_I2C_CR2_STOP			BIT(14)
90 #define STM32F7_I2C_CR2_START			BIT(13)
91 #define STM32F7_I2C_CR2_HEAD10R			BIT(12)
92 #define STM32F7_I2C_CR2_ADD10			BIT(11)
93 #define STM32F7_I2C_CR2_RD_WRN			BIT(10)
94 #define STM32F7_I2C_CR2_SADD10_MASK		GENMASK(9, 0)
95 #define STM32F7_I2C_CR2_SADD10(n)		(((n) & \
96 						STM32F7_I2C_CR2_SADD10_MASK))
97 #define STM32F7_I2C_CR2_SADD7_MASK		GENMASK(7, 1)
98 #define STM32F7_I2C_CR2_SADD7(n)		(((n) & 0x7f) << 1)
99 
100 /* STM32F7 I2C Own Address 1 */
101 #define STM32F7_I2C_OAR1_OA1EN			BIT(15)
102 #define STM32F7_I2C_OAR1_OA1MODE		BIT(10)
103 #define STM32F7_I2C_OAR1_OA1_10_MASK		GENMASK(9, 0)
104 #define STM32F7_I2C_OAR1_OA1_10(n)		(((n) & \
105 						STM32F7_I2C_OAR1_OA1_10_MASK))
106 #define STM32F7_I2C_OAR1_OA1_7_MASK		GENMASK(7, 1)
107 #define STM32F7_I2C_OAR1_OA1_7(n)		(((n) & 0x7f) << 1)
108 #define STM32F7_I2C_OAR1_MASK			(STM32F7_I2C_OAR1_OA1_7_MASK \
109 						| STM32F7_I2C_OAR1_OA1_10_MASK \
110 						| STM32F7_I2C_OAR1_OA1EN \
111 						| STM32F7_I2C_OAR1_OA1MODE)
112 
113 /* STM32F7 I2C Own Address 2 */
114 #define STM32F7_I2C_OAR2_OA2EN			BIT(15)
115 #define STM32F7_I2C_OAR2_OA2MSK_MASK		GENMASK(10, 8)
116 #define STM32F7_I2C_OAR2_OA2MSK(n)		(((n) & 0x7) << 8)
117 #define STM32F7_I2C_OAR2_OA2_7_MASK		GENMASK(7, 1)
118 #define STM32F7_I2C_OAR2_OA2_7(n)		(((n) & 0x7f) << 1)
119 #define STM32F7_I2C_OAR2_MASK			(STM32F7_I2C_OAR2_OA2MSK_MASK \
120 						| STM32F7_I2C_OAR2_OA2_7_MASK \
121 						| STM32F7_I2C_OAR2_OA2EN)
122 
123 /* STM32F7 I2C Interrupt Status */
124 #define STM32F7_I2C_ISR_ADDCODE_MASK		GENMASK(23, 17)
125 #define STM32F7_I2C_ISR_ADDCODE_GET(n) \
126 				(((n) & STM32F7_I2C_ISR_ADDCODE_MASK) >> 17)
127 #define STM32F7_I2C_ISR_DIR			BIT(16)
128 #define STM32F7_I2C_ISR_BUSY			BIT(15)
129 #define STM32F7_I2C_ISR_ALERT			BIT(13)
130 #define STM32F7_I2C_ISR_PECERR			BIT(11)
131 #define STM32F7_I2C_ISR_ARLO			BIT(9)
132 #define STM32F7_I2C_ISR_BERR			BIT(8)
133 #define STM32F7_I2C_ISR_TCR			BIT(7)
134 #define STM32F7_I2C_ISR_TC			BIT(6)
135 #define STM32F7_I2C_ISR_STOPF			BIT(5)
136 #define STM32F7_I2C_ISR_NACKF			BIT(4)
137 #define STM32F7_I2C_ISR_ADDR			BIT(3)
138 #define STM32F7_I2C_ISR_RXNE			BIT(2)
139 #define STM32F7_I2C_ISR_TXIS			BIT(1)
140 #define STM32F7_I2C_ISR_TXE			BIT(0)
141 
142 /* STM32F7 I2C Interrupt Clear */
143 #define STM32F7_I2C_ICR_ALERTCF			BIT(13)
144 #define STM32F7_I2C_ICR_PECCF			BIT(11)
145 #define STM32F7_I2C_ICR_ARLOCF			BIT(9)
146 #define STM32F7_I2C_ICR_BERRCF			BIT(8)
147 #define STM32F7_I2C_ICR_STOPCF			BIT(5)
148 #define STM32F7_I2C_ICR_NACKCF			BIT(4)
149 #define STM32F7_I2C_ICR_ADDRCF			BIT(3)
150 
151 /* STM32F7 I2C Timing */
152 #define STM32F7_I2C_TIMINGR_PRESC(n)		(((n) & 0xf) << 28)
153 #define STM32F7_I2C_TIMINGR_SCLDEL(n)		(((n) & 0xf) << 20)
154 #define STM32F7_I2C_TIMINGR_SDADEL(n)		(((n) & 0xf) << 16)
155 #define STM32F7_I2C_TIMINGR_SCLH(n)		(((n) & 0xff) << 8)
156 #define STM32F7_I2C_TIMINGR_SCLL(n)		((n) & 0xff)
157 
158 #define STM32F7_I2C_MAX_LEN			0xff
159 #define STM32F7_I2C_DMA_LEN_MIN			0x16
160 enum {
161 	STM32F7_SLAVE_HOSTNOTIFY,
162 	STM32F7_SLAVE_7_10_BITS_ADDR,
163 	STM32F7_SLAVE_7_BITS_ADDR,
164 	STM32F7_I2C_MAX_SLAVE
165 };
166 
167 #define STM32F7_I2C_DNF_DEFAULT			0
168 #define STM32F7_I2C_DNF_MAX			15
169 
170 #define STM32F7_I2C_ANALOG_FILTER_DELAY_MIN	50	/* ns */
171 #define STM32F7_I2C_ANALOG_FILTER_DELAY_MAX	260	/* ns */
172 
173 #define STM32F7_I2C_RISE_TIME_DEFAULT		25	/* ns */
174 #define STM32F7_I2C_FALL_TIME_DEFAULT		10	/* ns */
175 
176 #define STM32F7_PRESC_MAX			BIT(4)
177 #define STM32F7_SCLDEL_MAX			BIT(4)
178 #define STM32F7_SDADEL_MAX			BIT(4)
179 #define STM32F7_SCLH_MAX			BIT(8)
180 #define STM32F7_SCLL_MAX			BIT(8)
181 
182 #define STM32F7_AUTOSUSPEND_DELAY		(HZ / 100)
183 
184 /**
185  * struct stm32f7_i2c_regs - i2c f7 registers backup
186  * @cr1: Control register 1
187  * @cr2: Control register 2
188  * @oar1: Own address 1 register
189  * @oar2: Own address 2 register
190  * @tmgr: Timing register
191  */
192 struct stm32f7_i2c_regs {
193 	u32 cr1;
194 	u32 cr2;
195 	u32 oar1;
196 	u32 oar2;
197 	u32 tmgr;
198 };
199 
200 /**
201  * struct stm32f7_i2c_spec - private i2c specification timing
202  * @rate: I2C bus speed (Hz)
203  * @fall_max: Max fall time of both SDA and SCL signals (ns)
204  * @rise_max: Max rise time of both SDA and SCL signals (ns)
205  * @hddat_min: Min data hold time (ns)
206  * @vddat_max: Max data valid time (ns)
207  * @sudat_min: Min data setup time (ns)
208  * @l_min: Min low period of the SCL clock (ns)
209  * @h_min: Min high period of the SCL clock (ns)
210  */
211 struct stm32f7_i2c_spec {
212 	u32 rate;
213 	u32 fall_max;
214 	u32 rise_max;
215 	u32 hddat_min;
216 	u32 vddat_max;
217 	u32 sudat_min;
218 	u32 l_min;
219 	u32 h_min;
220 };
221 
222 /**
223  * struct stm32f7_i2c_setup - private I2C timing setup parameters
224  * @speed_freq: I2C speed frequency  (Hz)
225  * @clock_src: I2C clock source frequency (Hz)
226  * @rise_time: Rise time (ns)
227  * @fall_time: Fall time (ns)
228  * @fmp_clr_offset: Fast Mode Plus clear register offset from set register
229  */
230 struct stm32f7_i2c_setup {
231 	u32 speed_freq;
232 	u32 clock_src;
233 	u32 rise_time;
234 	u32 fall_time;
235 	u32 fmp_clr_offset;
236 };
237 
238 /**
239  * struct stm32f7_i2c_timings - private I2C output parameters
240  * @node: List entry
241  * @presc: Prescaler value
242  * @scldel: Data setup time
243  * @sdadel: Data hold time
244  * @sclh: SCL high period (master mode)
245  * @scll: SCL low period (master mode)
246  */
247 struct stm32f7_i2c_timings {
248 	struct list_head node;
249 	u8 presc;
250 	u8 scldel;
251 	u8 sdadel;
252 	u8 sclh;
253 	u8 scll;
254 };
255 
256 /**
257  * struct stm32f7_i2c_msg - client specific data
258  * @addr: 8-bit or 10-bit slave addr, including r/w bit
259  * @count: number of bytes to be transferred
260  * @buf: data buffer
261  * @result: result of the transfer
262  * @stop: last I2C msg to be sent, i.e. STOP to be generated
263  * @smbus: boolean to know if the I2C IP is used in SMBus mode
264  * @size: type of SMBus protocol
265  * @read_write: direction of SMBus protocol
266  * SMBus block read and SMBus block write - block read process call protocols
267  * @smbus_buf: buffer to be used for SMBus protocol transfer. It will
268  * contain a maximum of 32 bytes of data + byte command + byte count + PEC
269  * This buffer has to be 32-bit aligned to be compliant with memory address
270  * register in DMA mode.
271  */
272 struct stm32f7_i2c_msg {
273 	u16 addr;
274 	u32 count;
275 	u8 *buf;
276 	int result;
277 	bool stop;
278 	bool smbus;
279 	int size;
280 	char read_write;
281 	u8 smbus_buf[I2C_SMBUS_BLOCK_MAX + 3] __aligned(4);
282 };
283 
284 /**
285  * struct stm32f7_i2c_alert - SMBus alert specific data
286  * @setup: platform data for the smbus_alert i2c client
287  * @ara: I2C slave device used to respond to the SMBus Alert with Alert
288  * Response Address
289  */
290 struct stm32f7_i2c_alert {
291 	struct i2c_smbus_alert_setup setup;
292 	struct i2c_client *ara;
293 };
294 
295 /**
296  * struct stm32f7_i2c_dev - private data of the controller
297  * @adap: I2C adapter for this controller
298  * @dev: device for this controller
299  * @base: virtual memory area
300  * @complete: completion of I2C message
301  * @clk: hw i2c clock
302  * @bus_rate: I2C clock frequency of the controller
303  * @msg: Pointer to data to be written
304  * @msg_num: number of I2C messages to be executed
305  * @msg_id: message identifiant
306  * @f7_msg: customized i2c msg for driver usage
307  * @setup: I2C timing input setup
308  * @timing: I2C computed timings
309  * @slave: list of slave devices registered on the I2C bus
310  * @slave_running: slave device currently used
311  * @backup_regs: backup of i2c controller registers (for suspend/resume)
312  * @slave_dir: transfer direction for the current slave device
313  * @master_mode: boolean to know in which mode the I2C is running (master or
314  * slave)
315  * @dma: dma data
316  * @use_dma: boolean to know if dma is used in the current transfer
317  * @regmap: holds SYSCFG phandle for Fast Mode Plus bits
318  * @fmp_sreg: register address for setting Fast Mode Plus bits
319  * @fmp_creg: register address for clearing Fast Mode Plus bits
320  * @fmp_mask: mask for Fast Mode Plus bits in set register
321  * @wakeup_src: boolean to know if the device is a wakeup source
322  * @smbus_mode: states that the controller is configured in SMBus mode
323  * @host_notify_client: SMBus host-notify client
324  * @analog_filter: boolean to indicate enabling of the analog filter
325  * @dnf_dt: value of digital filter requested via dt
326  * @dnf: value of digital filter to apply
327  * @alert: SMBus alert specific data
328  */
329 struct stm32f7_i2c_dev {
330 	struct i2c_adapter adap;
331 	struct device *dev;
332 	void __iomem *base;
333 	struct completion complete;
334 	struct clk *clk;
335 	unsigned int bus_rate;
336 	struct i2c_msg *msg;
337 	unsigned int msg_num;
338 	unsigned int msg_id;
339 	struct stm32f7_i2c_msg f7_msg;
340 	struct stm32f7_i2c_setup setup;
341 	struct stm32f7_i2c_timings timing;
342 	struct i2c_client *slave[STM32F7_I2C_MAX_SLAVE];
343 	struct i2c_client *slave_running;
344 	struct stm32f7_i2c_regs backup_regs;
345 	u32 slave_dir;
346 	bool master_mode;
347 	struct stm32_i2c_dma *dma;
348 	bool use_dma;
349 	struct regmap *regmap;
350 	u32 fmp_sreg;
351 	u32 fmp_creg;
352 	u32 fmp_mask;
353 	bool wakeup_src;
354 	bool smbus_mode;
355 	struct i2c_client *host_notify_client;
356 	bool analog_filter;
357 	u32 dnf_dt;
358 	u32 dnf;
359 	struct stm32f7_i2c_alert *alert;
360 	bool atomic;
361 };
362 
363 /*
364  * All these values are coming from I2C Specification, Version 6.0, 4th of
365  * April 2014.
366  *
367  * Table10. Characteristics of the SDA and SCL bus lines for Standard, Fast,
368  * and Fast-mode Plus I2C-bus devices
369  */
370 static struct stm32f7_i2c_spec stm32f7_i2c_specs[] = {
371 	{
372 		.rate = I2C_MAX_STANDARD_MODE_FREQ,
373 		.fall_max = 300,
374 		.rise_max = 1000,
375 		.hddat_min = 0,
376 		.vddat_max = 3450,
377 		.sudat_min = 250,
378 		.l_min = 4700,
379 		.h_min = 4000,
380 	},
381 	{
382 		.rate = I2C_MAX_FAST_MODE_FREQ,
383 		.fall_max = 300,
384 		.rise_max = 300,
385 		.hddat_min = 0,
386 		.vddat_max = 900,
387 		.sudat_min = 100,
388 		.l_min = 1300,
389 		.h_min = 600,
390 	},
391 	{
392 		.rate = I2C_MAX_FAST_MODE_PLUS_FREQ,
393 		.fall_max = 100,
394 		.rise_max = 120,
395 		.hddat_min = 0,
396 		.vddat_max = 450,
397 		.sudat_min = 50,
398 		.l_min = 500,
399 		.h_min = 260,
400 	},
401 };
402 
403 static const struct stm32f7_i2c_setup stm32f7_setup = {
404 	.rise_time = STM32F7_I2C_RISE_TIME_DEFAULT,
405 	.fall_time = STM32F7_I2C_FALL_TIME_DEFAULT,
406 };
407 
408 static const struct stm32f7_i2c_setup stm32mp15_setup = {
409 	.rise_time = STM32F7_I2C_RISE_TIME_DEFAULT,
410 	.fall_time = STM32F7_I2C_FALL_TIME_DEFAULT,
411 	.fmp_clr_offset = 0x40,
412 };
413 
414 static const struct stm32f7_i2c_setup stm32mp13_setup = {
415 	.rise_time = STM32F7_I2C_RISE_TIME_DEFAULT,
416 	.fall_time = STM32F7_I2C_FALL_TIME_DEFAULT,
417 	.fmp_clr_offset = 0x4,
418 };
419 
stm32f7_i2c_set_bits(void __iomem * reg,u32 mask)420 static inline void stm32f7_i2c_set_bits(void __iomem *reg, u32 mask)
421 {
422 	writel_relaxed(readl_relaxed(reg) | mask, reg);
423 }
424 
stm32f7_i2c_clr_bits(void __iomem * reg,u32 mask)425 static inline void stm32f7_i2c_clr_bits(void __iomem *reg, u32 mask)
426 {
427 	writel_relaxed(readl_relaxed(reg) & ~mask, reg);
428 }
429 
stm32f7_i2c_disable_irq(struct stm32f7_i2c_dev * i2c_dev,u32 mask)430 static void stm32f7_i2c_disable_irq(struct stm32f7_i2c_dev *i2c_dev, u32 mask)
431 {
432 	stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1, mask);
433 }
434 
stm32f7_get_specs(u32 rate)435 static struct stm32f7_i2c_spec *stm32f7_get_specs(u32 rate)
436 {
437 	int i;
438 
439 	for (i = 0; i < ARRAY_SIZE(stm32f7_i2c_specs); i++)
440 		if (rate <= stm32f7_i2c_specs[i].rate)
441 			return &stm32f7_i2c_specs[i];
442 
443 	return ERR_PTR(-EINVAL);
444 }
445 
446 #define	RATE_MIN(rate)	((rate) * 8 / 10)
stm32f7_i2c_compute_timing(struct stm32f7_i2c_dev * i2c_dev,struct stm32f7_i2c_setup * setup,struct stm32f7_i2c_timings * output)447 static int stm32f7_i2c_compute_timing(struct stm32f7_i2c_dev *i2c_dev,
448 				      struct stm32f7_i2c_setup *setup,
449 				      struct stm32f7_i2c_timings *output)
450 {
451 	struct stm32f7_i2c_spec *specs;
452 	u32 p_prev = STM32F7_PRESC_MAX;
453 	u32 i2cclk = DIV_ROUND_CLOSEST(NSEC_PER_SEC,
454 				       setup->clock_src);
455 	u32 i2cbus = DIV_ROUND_CLOSEST(NSEC_PER_SEC,
456 				       setup->speed_freq);
457 	u32 clk_error_prev = i2cbus;
458 	u32 tsync;
459 	u32 af_delay_min, af_delay_max;
460 	u32 dnf_delay;
461 	u32 clk_min, clk_max;
462 	int sdadel_min, sdadel_max;
463 	int scldel_min;
464 	struct stm32f7_i2c_timings *v, *_v, *s;
465 	struct list_head solutions;
466 	u16 p, l, a, h;
467 	int ret = 0;
468 
469 	specs = stm32f7_get_specs(setup->speed_freq);
470 	if (specs == ERR_PTR(-EINVAL)) {
471 		dev_err(i2c_dev->dev, "speed out of bound {%d}\n",
472 			setup->speed_freq);
473 		return -EINVAL;
474 	}
475 
476 	if ((setup->rise_time > specs->rise_max) ||
477 	    (setup->fall_time > specs->fall_max)) {
478 		dev_err(i2c_dev->dev,
479 			"timings out of bound Rise{%d>%d}/Fall{%d>%d}\n",
480 			setup->rise_time, specs->rise_max,
481 			setup->fall_time, specs->fall_max);
482 		return -EINVAL;
483 	}
484 
485 	i2c_dev->dnf = DIV_ROUND_CLOSEST(i2c_dev->dnf_dt, i2cclk);
486 	if (i2c_dev->dnf > STM32F7_I2C_DNF_MAX) {
487 		dev_err(i2c_dev->dev,
488 			"DNF out of bound %d/%d\n",
489 			i2c_dev->dnf * i2cclk, STM32F7_I2C_DNF_MAX * i2cclk);
490 		return -EINVAL;
491 	}
492 
493 	/*  Analog and Digital Filters */
494 	af_delay_min =
495 		(i2c_dev->analog_filter ?
496 		 STM32F7_I2C_ANALOG_FILTER_DELAY_MIN : 0);
497 	af_delay_max =
498 		(i2c_dev->analog_filter ?
499 		 STM32F7_I2C_ANALOG_FILTER_DELAY_MAX : 0);
500 	dnf_delay = i2c_dev->dnf * i2cclk;
501 
502 	sdadel_min = specs->hddat_min + setup->fall_time -
503 		af_delay_min - (i2c_dev->dnf + 3) * i2cclk;
504 
505 	sdadel_max = specs->vddat_max - setup->rise_time -
506 		af_delay_max - (i2c_dev->dnf + 4) * i2cclk;
507 
508 	scldel_min = setup->rise_time + specs->sudat_min;
509 
510 	if (sdadel_min < 0)
511 		sdadel_min = 0;
512 	if (sdadel_max < 0)
513 		sdadel_max = 0;
514 
515 	dev_dbg(i2c_dev->dev, "SDADEL(min/max): %i/%i, SCLDEL(Min): %i\n",
516 		sdadel_min, sdadel_max, scldel_min);
517 
518 	INIT_LIST_HEAD(&solutions);
519 	/* Compute possible values for PRESC, SCLDEL and SDADEL */
520 	for (p = 0; p < STM32F7_PRESC_MAX; p++) {
521 		for (l = 0; l < STM32F7_SCLDEL_MAX; l++) {
522 			u32 scldel = (l + 1) * (p + 1) * i2cclk;
523 
524 			if (scldel < scldel_min)
525 				continue;
526 
527 			for (a = 0; a < STM32F7_SDADEL_MAX; a++) {
528 				u32 sdadel = (a * (p + 1) + 1) * i2cclk;
529 
530 				if (((sdadel >= sdadel_min) &&
531 				     (sdadel <= sdadel_max)) &&
532 				    (p != p_prev)) {
533 					v = kmalloc(sizeof(*v), GFP_KERNEL);
534 					if (!v) {
535 						ret = -ENOMEM;
536 						goto exit;
537 					}
538 
539 					v->presc = p;
540 					v->scldel = l;
541 					v->sdadel = a;
542 					p_prev = p;
543 
544 					list_add_tail(&v->node,
545 						      &solutions);
546 					break;
547 				}
548 			}
549 
550 			if (p_prev == p)
551 				break;
552 		}
553 	}
554 
555 	if (list_empty(&solutions)) {
556 		dev_err(i2c_dev->dev, "no Prescaler solution\n");
557 		ret = -EPERM;
558 		goto exit;
559 	}
560 
561 	tsync = af_delay_min + dnf_delay + (2 * i2cclk);
562 	s = NULL;
563 	clk_max = NSEC_PER_SEC / RATE_MIN(setup->speed_freq);
564 	clk_min = NSEC_PER_SEC / setup->speed_freq;
565 
566 	/*
567 	 * Among Prescaler possibilities discovered above figures out SCL Low
568 	 * and High Period. Provided:
569 	 * - SCL Low Period has to be higher than SCL Clock Low Period
570 	 *   defined by I2C Specification. I2C Clock has to be lower than
571 	 *   (SCL Low Period - Analog/Digital filters) / 4.
572 	 * - SCL High Period has to be lower than SCL Clock High Period
573 	 *   defined by I2C Specification
574 	 * - I2C Clock has to be lower than SCL High Period
575 	 */
576 	list_for_each_entry(v, &solutions, node) {
577 		u32 prescaler = (v->presc + 1) * i2cclk;
578 
579 		for (l = 0; l < STM32F7_SCLL_MAX; l++) {
580 			u32 tscl_l = (l + 1) * prescaler + tsync;
581 
582 			if ((tscl_l < specs->l_min) ||
583 			    (i2cclk >=
584 			     ((tscl_l - af_delay_min - dnf_delay) / 4))) {
585 				continue;
586 			}
587 
588 			for (h = 0; h < STM32F7_SCLH_MAX; h++) {
589 				u32 tscl_h = (h + 1) * prescaler + tsync;
590 				u32 tscl = tscl_l + tscl_h +
591 					setup->rise_time + setup->fall_time;
592 
593 				if ((tscl >= clk_min) && (tscl <= clk_max) &&
594 				    (tscl_h >= specs->h_min) &&
595 				    (i2cclk < tscl_h)) {
596 					int clk_error = tscl - i2cbus;
597 
598 					if (clk_error < 0)
599 						clk_error = -clk_error;
600 
601 					if (clk_error < clk_error_prev) {
602 						clk_error_prev = clk_error;
603 						v->scll = l;
604 						v->sclh = h;
605 						s = v;
606 					}
607 				}
608 			}
609 		}
610 	}
611 
612 	if (!s) {
613 		dev_err(i2c_dev->dev, "no solution at all\n");
614 		ret = -EPERM;
615 		goto exit;
616 	}
617 
618 	output->presc = s->presc;
619 	output->scldel = s->scldel;
620 	output->sdadel = s->sdadel;
621 	output->scll = s->scll;
622 	output->sclh = s->sclh;
623 
624 	dev_dbg(i2c_dev->dev,
625 		"Presc: %i, scldel: %i, sdadel: %i, scll: %i, sclh: %i\n",
626 		output->presc,
627 		output->scldel, output->sdadel,
628 		output->scll, output->sclh);
629 
630 exit:
631 	/* Release list and memory */
632 	list_for_each_entry_safe(v, _v, &solutions, node) {
633 		list_del(&v->node);
634 		kfree(v);
635 	}
636 
637 	return ret;
638 }
639 
stm32f7_get_lower_rate(u32 rate)640 static u32 stm32f7_get_lower_rate(u32 rate)
641 {
642 	int i = ARRAY_SIZE(stm32f7_i2c_specs);
643 
644 	while (--i)
645 		if (stm32f7_i2c_specs[i].rate < rate)
646 			break;
647 
648 	return stm32f7_i2c_specs[i].rate;
649 }
650 
stm32f7_i2c_setup_timing(struct stm32f7_i2c_dev * i2c_dev,struct stm32f7_i2c_setup * setup)651 static int stm32f7_i2c_setup_timing(struct stm32f7_i2c_dev *i2c_dev,
652 				    struct stm32f7_i2c_setup *setup)
653 {
654 	struct i2c_timings timings, *t = &timings;
655 	int ret = 0;
656 
657 	t->bus_freq_hz = I2C_MAX_STANDARD_MODE_FREQ;
658 	t->scl_rise_ns = i2c_dev->setup.rise_time;
659 	t->scl_fall_ns = i2c_dev->setup.fall_time;
660 
661 	i2c_parse_fw_timings(i2c_dev->dev, t, false);
662 
663 	if (t->bus_freq_hz > I2C_MAX_FAST_MODE_PLUS_FREQ) {
664 		dev_err(i2c_dev->dev, "Invalid bus speed (%i>%i)\n",
665 			t->bus_freq_hz, I2C_MAX_FAST_MODE_PLUS_FREQ);
666 		return -EINVAL;
667 	}
668 
669 	setup->speed_freq = t->bus_freq_hz;
670 	i2c_dev->setup.rise_time = t->scl_rise_ns;
671 	i2c_dev->setup.fall_time = t->scl_fall_ns;
672 	i2c_dev->dnf_dt = t->digital_filter_width_ns;
673 	setup->clock_src = clk_get_rate(i2c_dev->clk);
674 
675 	if (!setup->clock_src) {
676 		dev_err(i2c_dev->dev, "clock rate is 0\n");
677 		return -EINVAL;
678 	}
679 
680 	if (!of_property_read_bool(i2c_dev->dev->of_node, "i2c-digital-filter"))
681 		i2c_dev->dnf_dt = STM32F7_I2C_DNF_DEFAULT;
682 
683 	do {
684 		ret = stm32f7_i2c_compute_timing(i2c_dev, setup,
685 						 &i2c_dev->timing);
686 		if (ret) {
687 			dev_err(i2c_dev->dev,
688 				"failed to compute I2C timings.\n");
689 			if (setup->speed_freq <= I2C_MAX_STANDARD_MODE_FREQ)
690 				break;
691 			setup->speed_freq =
692 				stm32f7_get_lower_rate(setup->speed_freq);
693 			dev_warn(i2c_dev->dev,
694 				 "downgrade I2C Speed Freq to (%i)\n",
695 				 setup->speed_freq);
696 		}
697 	} while (ret);
698 
699 	if (ret) {
700 		dev_err(i2c_dev->dev, "Impossible to compute I2C timings.\n");
701 		return ret;
702 	}
703 
704 	i2c_dev->analog_filter = of_property_read_bool(i2c_dev->dev->of_node,
705 						       "i2c-analog-filter");
706 
707 	dev_dbg(i2c_dev->dev, "I2C Speed(%i), Clk Source(%i)\n",
708 		setup->speed_freq, setup->clock_src);
709 	dev_dbg(i2c_dev->dev, "I2C Rise(%i) and Fall(%i) Time\n",
710 		setup->rise_time, setup->fall_time);
711 	dev_dbg(i2c_dev->dev, "I2C Analog Filter(%s), DNF(%i)\n",
712 		(i2c_dev->analog_filter ? "On" : "Off"), i2c_dev->dnf);
713 
714 	i2c_dev->bus_rate = setup->speed_freq;
715 
716 	return 0;
717 }
718 
stm32f7_i2c_disable_dma_req(struct stm32f7_i2c_dev * i2c_dev)719 static void stm32f7_i2c_disable_dma_req(struct stm32f7_i2c_dev *i2c_dev)
720 {
721 	void __iomem *base = i2c_dev->base;
722 	u32 mask = STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN;
723 
724 	stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, mask);
725 }
726 
stm32f7_i2c_dma_callback(void * arg)727 static void stm32f7_i2c_dma_callback(void *arg)
728 {
729 	struct stm32f7_i2c_dev *i2c_dev = (struct stm32f7_i2c_dev *)arg;
730 	struct stm32_i2c_dma *dma = i2c_dev->dma;
731 	struct device *dev = dma->chan_using->device->dev;
732 
733 	stm32f7_i2c_disable_dma_req(i2c_dev);
734 	dma_unmap_single(dev, dma->dma_buf, dma->dma_len, dma->dma_data_dir);
735 	complete(&dma->dma_complete);
736 }
737 
stm32f7_i2c_hw_config(struct stm32f7_i2c_dev * i2c_dev)738 static void stm32f7_i2c_hw_config(struct stm32f7_i2c_dev *i2c_dev)
739 {
740 	struct stm32f7_i2c_timings *t = &i2c_dev->timing;
741 	u32 timing = 0;
742 
743 	/* Timing settings */
744 	timing |= STM32F7_I2C_TIMINGR_PRESC(t->presc);
745 	timing |= STM32F7_I2C_TIMINGR_SCLDEL(t->scldel);
746 	timing |= STM32F7_I2C_TIMINGR_SDADEL(t->sdadel);
747 	timing |= STM32F7_I2C_TIMINGR_SCLH(t->sclh);
748 	timing |= STM32F7_I2C_TIMINGR_SCLL(t->scll);
749 	writel_relaxed(timing, i2c_dev->base + STM32F7_I2C_TIMINGR);
750 
751 	/* Configure the Analog Filter */
752 	if (i2c_dev->analog_filter)
753 		stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1,
754 				     STM32F7_I2C_CR1_ANFOFF);
755 	else
756 		stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,
757 				     STM32F7_I2C_CR1_ANFOFF);
758 
759 	/* Program the Digital Filter */
760 	stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1,
761 			     STM32F7_I2C_CR1_DNF_MASK);
762 	stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,
763 			     STM32F7_I2C_CR1_DNF(i2c_dev->dnf));
764 
765 	stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,
766 			     STM32F7_I2C_CR1_PE);
767 }
768 
stm32f7_i2c_write_tx_data(struct stm32f7_i2c_dev * i2c_dev)769 static void stm32f7_i2c_write_tx_data(struct stm32f7_i2c_dev *i2c_dev)
770 {
771 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
772 	void __iomem *base = i2c_dev->base;
773 
774 	if (f7_msg->count) {
775 		writeb_relaxed(*f7_msg->buf++, base + STM32F7_I2C_TXDR);
776 		f7_msg->count--;
777 	}
778 }
779 
stm32f7_i2c_read_rx_data(struct stm32f7_i2c_dev * i2c_dev)780 static void stm32f7_i2c_read_rx_data(struct stm32f7_i2c_dev *i2c_dev)
781 {
782 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
783 	void __iomem *base = i2c_dev->base;
784 
785 	if (f7_msg->count) {
786 		*f7_msg->buf++ = readb_relaxed(base + STM32F7_I2C_RXDR);
787 		f7_msg->count--;
788 	} else {
789 		/* Flush RX buffer has no data is expected */
790 		readb_relaxed(base + STM32F7_I2C_RXDR);
791 	}
792 }
793 
stm32f7_i2c_reload(struct stm32f7_i2c_dev * i2c_dev)794 static void stm32f7_i2c_reload(struct stm32f7_i2c_dev *i2c_dev)
795 {
796 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
797 	u32 cr2;
798 
799 	if (i2c_dev->use_dma)
800 		f7_msg->count -= STM32F7_I2C_MAX_LEN;
801 
802 	cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
803 
804 	cr2 &= ~STM32F7_I2C_CR2_NBYTES_MASK;
805 	if (f7_msg->count > STM32F7_I2C_MAX_LEN) {
806 		cr2 |= STM32F7_I2C_CR2_NBYTES(STM32F7_I2C_MAX_LEN);
807 	} else {
808 		cr2 &= ~STM32F7_I2C_CR2_RELOAD;
809 		cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
810 	}
811 
812 	writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2);
813 }
814 
stm32f7_i2c_smbus_reload(struct stm32f7_i2c_dev * i2c_dev)815 static void stm32f7_i2c_smbus_reload(struct stm32f7_i2c_dev *i2c_dev)
816 {
817 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
818 	u32 cr2;
819 	u8 *val;
820 
821 	/*
822 	 * For I2C_SMBUS_BLOCK_DATA && I2C_SMBUS_BLOCK_PROC_CALL, the first
823 	 * data received inform us how many data will follow.
824 	 */
825 	stm32f7_i2c_read_rx_data(i2c_dev);
826 
827 	/*
828 	 * Update NBYTES with the value read to continue the transfer
829 	 */
830 	val = f7_msg->buf - sizeof(u8);
831 	f7_msg->count = *val;
832 	cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
833 	cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK | STM32F7_I2C_CR2_RELOAD);
834 	cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
835 	writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2);
836 }
837 
stm32f7_i2c_release_bus(struct i2c_adapter * i2c_adap)838 static void stm32f7_i2c_release_bus(struct i2c_adapter *i2c_adap)
839 {
840 	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap);
841 
842 	stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1,
843 			     STM32F7_I2C_CR1_PE);
844 
845 	stm32f7_i2c_hw_config(i2c_dev);
846 }
847 
stm32f7_i2c_wait_free_bus(struct stm32f7_i2c_dev * i2c_dev)848 static int stm32f7_i2c_wait_free_bus(struct stm32f7_i2c_dev *i2c_dev)
849 {
850 	u32 status;
851 	int ret;
852 
853 	ret = readl_relaxed_poll_timeout(i2c_dev->base + STM32F7_I2C_ISR,
854 					 status,
855 					 !(status & STM32F7_I2C_ISR_BUSY),
856 					 10, 1000);
857 	if (!ret)
858 		return 0;
859 
860 	stm32f7_i2c_release_bus(&i2c_dev->adap);
861 
862 	return -EBUSY;
863 }
864 
stm32f7_i2c_xfer_msg(struct stm32f7_i2c_dev * i2c_dev,struct i2c_msg * msg)865 static void stm32f7_i2c_xfer_msg(struct stm32f7_i2c_dev *i2c_dev,
866 				 struct i2c_msg *msg)
867 {
868 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
869 	void __iomem *base = i2c_dev->base;
870 	u32 cr1, cr2;
871 	int ret;
872 
873 	f7_msg->addr = msg->addr;
874 	f7_msg->buf = msg->buf;
875 	f7_msg->count = msg->len;
876 	f7_msg->result = 0;
877 	f7_msg->stop = (i2c_dev->msg_id >= i2c_dev->msg_num - 1);
878 
879 	reinit_completion(&i2c_dev->complete);
880 
881 	cr1 = readl_relaxed(base + STM32F7_I2C_CR1);
882 	cr2 = readl_relaxed(base + STM32F7_I2C_CR2);
883 
884 	/* Set transfer direction */
885 	cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
886 	if (msg->flags & I2C_M_RD)
887 		cr2 |= STM32F7_I2C_CR2_RD_WRN;
888 
889 	/* Set slave address */
890 	cr2 &= ~(STM32F7_I2C_CR2_HEAD10R | STM32F7_I2C_CR2_ADD10);
891 	if (msg->flags & I2C_M_TEN) {
892 		cr2 &= ~STM32F7_I2C_CR2_SADD10_MASK;
893 		cr2 |= STM32F7_I2C_CR2_SADD10(f7_msg->addr);
894 		cr2 |= STM32F7_I2C_CR2_ADD10;
895 	} else {
896 		cr2 &= ~STM32F7_I2C_CR2_SADD7_MASK;
897 		cr2 |= STM32F7_I2C_CR2_SADD7(f7_msg->addr);
898 	}
899 
900 	/* Set nb bytes to transfer and reload if needed */
901 	cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK | STM32F7_I2C_CR2_RELOAD);
902 	if (f7_msg->count > STM32F7_I2C_MAX_LEN) {
903 		cr2 |= STM32F7_I2C_CR2_NBYTES(STM32F7_I2C_MAX_LEN);
904 		cr2 |= STM32F7_I2C_CR2_RELOAD;
905 	} else {
906 		cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
907 	}
908 
909 	/* Enable NACK, STOP, error and transfer complete interrupts */
910 	cr1 |= STM32F7_I2C_CR1_ERRIE | STM32F7_I2C_CR1_TCIE |
911 		STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE;
912 
913 	/* Clear DMA req and TX/RX interrupt */
914 	cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE |
915 			STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN);
916 
917 	/* Configure DMA or enable RX/TX interrupt */
918 	i2c_dev->use_dma = false;
919 	if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN
920 	    && !i2c_dev->atomic) {
921 		ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma,
922 					      msg->flags & I2C_M_RD,
923 					      f7_msg->count, f7_msg->buf,
924 					      stm32f7_i2c_dma_callback,
925 					      i2c_dev);
926 		if (!ret)
927 			i2c_dev->use_dma = true;
928 		else
929 			dev_warn(i2c_dev->dev, "can't use DMA\n");
930 	}
931 
932 	if (!i2c_dev->use_dma) {
933 		if (msg->flags & I2C_M_RD)
934 			cr1 |= STM32F7_I2C_CR1_RXIE;
935 		else
936 			cr1 |= STM32F7_I2C_CR1_TXIE;
937 	} else {
938 		if (msg->flags & I2C_M_RD)
939 			cr1 |= STM32F7_I2C_CR1_RXDMAEN;
940 		else
941 			cr1 |= STM32F7_I2C_CR1_TXDMAEN;
942 	}
943 
944 	if (i2c_dev->atomic)
945 		cr1 &= ~STM32F7_I2C_ALL_IRQ_MASK; /* Disable all interrupts */
946 
947 	/* Configure Start/Repeated Start */
948 	cr2 |= STM32F7_I2C_CR2_START;
949 
950 	i2c_dev->master_mode = true;
951 
952 	/* Write configurations registers */
953 	writel_relaxed(cr1, base + STM32F7_I2C_CR1);
954 	writel_relaxed(cr2, base + STM32F7_I2C_CR2);
955 }
956 
stm32f7_i2c_smbus_xfer_msg(struct stm32f7_i2c_dev * i2c_dev,unsigned short flags,u8 command,union i2c_smbus_data * data)957 static int stm32f7_i2c_smbus_xfer_msg(struct stm32f7_i2c_dev *i2c_dev,
958 				      unsigned short flags, u8 command,
959 				      union i2c_smbus_data *data)
960 {
961 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
962 	struct device *dev = i2c_dev->dev;
963 	void __iomem *base = i2c_dev->base;
964 	u32 cr1, cr2;
965 	int i, ret;
966 
967 	f7_msg->result = 0;
968 	reinit_completion(&i2c_dev->complete);
969 
970 	cr2 = readl_relaxed(base + STM32F7_I2C_CR2);
971 	cr1 = readl_relaxed(base + STM32F7_I2C_CR1);
972 
973 	/* Set transfer direction */
974 	cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
975 	if (f7_msg->read_write)
976 		cr2 |= STM32F7_I2C_CR2_RD_WRN;
977 
978 	/* Set slave address */
979 	cr2 &= ~(STM32F7_I2C_CR2_ADD10 | STM32F7_I2C_CR2_SADD7_MASK);
980 	cr2 |= STM32F7_I2C_CR2_SADD7(f7_msg->addr);
981 
982 	f7_msg->smbus_buf[0] = command;
983 	switch (f7_msg->size) {
984 	case I2C_SMBUS_QUICK:
985 		f7_msg->stop = true;
986 		f7_msg->count = 0;
987 		break;
988 	case I2C_SMBUS_BYTE:
989 		f7_msg->stop = true;
990 		f7_msg->count = 1;
991 		break;
992 	case I2C_SMBUS_BYTE_DATA:
993 		if (f7_msg->read_write) {
994 			f7_msg->stop = false;
995 			f7_msg->count = 1;
996 			cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
997 		} else {
998 			f7_msg->stop = true;
999 			f7_msg->count = 2;
1000 			f7_msg->smbus_buf[1] = data->byte;
1001 		}
1002 		break;
1003 	case I2C_SMBUS_WORD_DATA:
1004 		if (f7_msg->read_write) {
1005 			f7_msg->stop = false;
1006 			f7_msg->count = 1;
1007 			cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
1008 		} else {
1009 			f7_msg->stop = true;
1010 			f7_msg->count = 3;
1011 			f7_msg->smbus_buf[1] = data->word & 0xff;
1012 			f7_msg->smbus_buf[2] = data->word >> 8;
1013 		}
1014 		break;
1015 	case I2C_SMBUS_BLOCK_DATA:
1016 		if (f7_msg->read_write) {
1017 			f7_msg->stop = false;
1018 			f7_msg->count = 1;
1019 			cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
1020 		} else {
1021 			f7_msg->stop = true;
1022 			if (data->block[0] > I2C_SMBUS_BLOCK_MAX ||
1023 			    !data->block[0]) {
1024 				dev_err(dev, "Invalid block write size %d\n",
1025 					data->block[0]);
1026 				return -EINVAL;
1027 			}
1028 			f7_msg->count = data->block[0] + 2;
1029 			for (i = 1; i < f7_msg->count; i++)
1030 				f7_msg->smbus_buf[i] = data->block[i - 1];
1031 		}
1032 		break;
1033 	case I2C_SMBUS_PROC_CALL:
1034 		f7_msg->stop = false;
1035 		f7_msg->count = 3;
1036 		f7_msg->smbus_buf[1] = data->word & 0xff;
1037 		f7_msg->smbus_buf[2] = data->word >> 8;
1038 		cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
1039 		f7_msg->read_write = I2C_SMBUS_READ;
1040 		break;
1041 	case I2C_SMBUS_BLOCK_PROC_CALL:
1042 		f7_msg->stop = false;
1043 		if (data->block[0] > I2C_SMBUS_BLOCK_MAX - 1) {
1044 			dev_err(dev, "Invalid block write size %d\n",
1045 				data->block[0]);
1046 			return -EINVAL;
1047 		}
1048 		f7_msg->count = data->block[0] + 2;
1049 		for (i = 1; i < f7_msg->count; i++)
1050 			f7_msg->smbus_buf[i] = data->block[i - 1];
1051 		cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
1052 		f7_msg->read_write = I2C_SMBUS_READ;
1053 		break;
1054 	case I2C_SMBUS_I2C_BLOCK_DATA:
1055 		/* Rely on emulated i2c transfer (through master_xfer) */
1056 		return -EOPNOTSUPP;
1057 	default:
1058 		dev_err(dev, "Unsupported smbus protocol %d\n", f7_msg->size);
1059 		return -EOPNOTSUPP;
1060 	}
1061 
1062 	f7_msg->buf = f7_msg->smbus_buf;
1063 
1064 	/* Configure PEC */
1065 	if ((flags & I2C_CLIENT_PEC) && f7_msg->size != I2C_SMBUS_QUICK) {
1066 		cr1 |= STM32F7_I2C_CR1_PECEN;
1067 		if (!f7_msg->read_write) {
1068 			cr2 |= STM32F7_I2C_CR2_PECBYTE;
1069 			f7_msg->count++;
1070 		}
1071 	} else {
1072 		cr1 &= ~STM32F7_I2C_CR1_PECEN;
1073 		cr2 &= ~STM32F7_I2C_CR2_PECBYTE;
1074 	}
1075 
1076 	/* Set number of bytes to be transferred */
1077 	cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK | STM32F7_I2C_CR2_RELOAD);
1078 	cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
1079 
1080 	/* Enable NACK, STOP, error and transfer complete interrupts */
1081 	cr1 |= STM32F7_I2C_CR1_ERRIE | STM32F7_I2C_CR1_TCIE |
1082 		STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE;
1083 
1084 	/* Clear DMA req and TX/RX interrupt */
1085 	cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE |
1086 			STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN);
1087 
1088 	/* Configure DMA or enable RX/TX interrupt */
1089 	i2c_dev->use_dma = false;
1090 	if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN) {
1091 		ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma,
1092 					      cr2 & STM32F7_I2C_CR2_RD_WRN,
1093 					      f7_msg->count, f7_msg->buf,
1094 					      stm32f7_i2c_dma_callback,
1095 					      i2c_dev);
1096 		if (!ret)
1097 			i2c_dev->use_dma = true;
1098 		else
1099 			dev_warn(i2c_dev->dev, "can't use DMA\n");
1100 	}
1101 
1102 	if (!i2c_dev->use_dma) {
1103 		if (cr2 & STM32F7_I2C_CR2_RD_WRN)
1104 			cr1 |= STM32F7_I2C_CR1_RXIE;
1105 		else
1106 			cr1 |= STM32F7_I2C_CR1_TXIE;
1107 	} else {
1108 		if (cr2 & STM32F7_I2C_CR2_RD_WRN)
1109 			cr1 |= STM32F7_I2C_CR1_RXDMAEN;
1110 		else
1111 			cr1 |= STM32F7_I2C_CR1_TXDMAEN;
1112 	}
1113 
1114 	/* Set Start bit */
1115 	cr2 |= STM32F7_I2C_CR2_START;
1116 
1117 	i2c_dev->master_mode = true;
1118 
1119 	/* Write configurations registers */
1120 	writel_relaxed(cr1, base + STM32F7_I2C_CR1);
1121 	writel_relaxed(cr2, base + STM32F7_I2C_CR2);
1122 
1123 	return 0;
1124 }
1125 
stm32f7_i2c_smbus_rep_start(struct stm32f7_i2c_dev * i2c_dev)1126 static void stm32f7_i2c_smbus_rep_start(struct stm32f7_i2c_dev *i2c_dev)
1127 {
1128 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1129 	void __iomem *base = i2c_dev->base;
1130 	u32 cr1, cr2;
1131 	int ret;
1132 
1133 	cr2 = readl_relaxed(base + STM32F7_I2C_CR2);
1134 	cr1 = readl_relaxed(base + STM32F7_I2C_CR1);
1135 
1136 	/* Set transfer direction */
1137 	cr2 |= STM32F7_I2C_CR2_RD_WRN;
1138 
1139 	switch (f7_msg->size) {
1140 	case I2C_SMBUS_BYTE_DATA:
1141 		f7_msg->count = 1;
1142 		break;
1143 	case I2C_SMBUS_WORD_DATA:
1144 	case I2C_SMBUS_PROC_CALL:
1145 		f7_msg->count = 2;
1146 		break;
1147 	case I2C_SMBUS_BLOCK_DATA:
1148 	case I2C_SMBUS_BLOCK_PROC_CALL:
1149 		f7_msg->count = 1;
1150 		cr2 |= STM32F7_I2C_CR2_RELOAD;
1151 		break;
1152 	}
1153 
1154 	f7_msg->buf = f7_msg->smbus_buf;
1155 	f7_msg->stop = true;
1156 
1157 	/* Add one byte for PEC if needed */
1158 	if (cr1 & STM32F7_I2C_CR1_PECEN) {
1159 		cr2 |= STM32F7_I2C_CR2_PECBYTE;
1160 		f7_msg->count++;
1161 	}
1162 
1163 	/* Set number of bytes to be transferred */
1164 	cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK);
1165 	cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
1166 
1167 	/*
1168 	 * Configure RX/TX interrupt:
1169 	 */
1170 	cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE);
1171 	cr1 |= STM32F7_I2C_CR1_RXIE;
1172 
1173 	/*
1174 	 * Configure DMA or enable RX/TX interrupt:
1175 	 * For I2C_SMBUS_BLOCK_DATA and I2C_SMBUS_BLOCK_PROC_CALL we don't use
1176 	 * dma as we don't know in advance how many data will be received
1177 	 */
1178 	cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE |
1179 		 STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN);
1180 
1181 	i2c_dev->use_dma = false;
1182 	if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN &&
1183 	    f7_msg->size != I2C_SMBUS_BLOCK_DATA &&
1184 	    f7_msg->size != I2C_SMBUS_BLOCK_PROC_CALL) {
1185 		ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma,
1186 					      cr2 & STM32F7_I2C_CR2_RD_WRN,
1187 					      f7_msg->count, f7_msg->buf,
1188 					      stm32f7_i2c_dma_callback,
1189 					      i2c_dev);
1190 
1191 		if (!ret)
1192 			i2c_dev->use_dma = true;
1193 		else
1194 			dev_warn(i2c_dev->dev, "can't use DMA\n");
1195 	}
1196 
1197 	if (!i2c_dev->use_dma)
1198 		cr1 |= STM32F7_I2C_CR1_RXIE;
1199 	else
1200 		cr1 |= STM32F7_I2C_CR1_RXDMAEN;
1201 
1202 	/* Configure Repeated Start */
1203 	cr2 |= STM32F7_I2C_CR2_START;
1204 
1205 	/* Write configurations registers */
1206 	writel_relaxed(cr1, base + STM32F7_I2C_CR1);
1207 	writel_relaxed(cr2, base + STM32F7_I2C_CR2);
1208 }
1209 
stm32f7_i2c_smbus_check_pec(struct stm32f7_i2c_dev * i2c_dev)1210 static int stm32f7_i2c_smbus_check_pec(struct stm32f7_i2c_dev *i2c_dev)
1211 {
1212 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1213 	u8 count, internal_pec, received_pec;
1214 
1215 	internal_pec = readl_relaxed(i2c_dev->base + STM32F7_I2C_PECR);
1216 
1217 	switch (f7_msg->size) {
1218 	case I2C_SMBUS_BYTE:
1219 	case I2C_SMBUS_BYTE_DATA:
1220 		received_pec = f7_msg->smbus_buf[1];
1221 		break;
1222 	case I2C_SMBUS_WORD_DATA:
1223 	case I2C_SMBUS_PROC_CALL:
1224 		received_pec = f7_msg->smbus_buf[2];
1225 		break;
1226 	case I2C_SMBUS_BLOCK_DATA:
1227 	case I2C_SMBUS_BLOCK_PROC_CALL:
1228 		count = f7_msg->smbus_buf[0];
1229 		received_pec = f7_msg->smbus_buf[count];
1230 		break;
1231 	default:
1232 		dev_err(i2c_dev->dev, "Unsupported smbus protocol for PEC\n");
1233 		return -EINVAL;
1234 	}
1235 
1236 	if (internal_pec != received_pec) {
1237 		dev_err(i2c_dev->dev, "Bad PEC 0x%02x vs. 0x%02x\n",
1238 			internal_pec, received_pec);
1239 		return -EBADMSG;
1240 	}
1241 
1242 	return 0;
1243 }
1244 
stm32f7_i2c_is_addr_match(struct i2c_client * slave,u32 addcode)1245 static bool stm32f7_i2c_is_addr_match(struct i2c_client *slave, u32 addcode)
1246 {
1247 	u32 addr;
1248 
1249 	if (!slave)
1250 		return false;
1251 
1252 	if (slave->flags & I2C_CLIENT_TEN) {
1253 		/*
1254 		 * For 10-bit addr, addcode = 11110XY with
1255 		 * X = Bit 9 of slave address
1256 		 * Y = Bit 8 of slave address
1257 		 */
1258 		addr = slave->addr >> 8;
1259 		addr |= 0x78;
1260 		if (addr == addcode)
1261 			return true;
1262 	} else {
1263 		addr = slave->addr & 0x7f;
1264 		if (addr == addcode)
1265 			return true;
1266 	}
1267 
1268 	return false;
1269 }
1270 
stm32f7_i2c_slave_start(struct stm32f7_i2c_dev * i2c_dev)1271 static void stm32f7_i2c_slave_start(struct stm32f7_i2c_dev *i2c_dev)
1272 {
1273 	struct i2c_client *slave = i2c_dev->slave_running;
1274 	void __iomem *base = i2c_dev->base;
1275 	u32 mask;
1276 	u8 value = 0;
1277 
1278 	if (i2c_dev->slave_dir) {
1279 		/* Notify i2c slave that new read transfer is starting */
1280 		i2c_slave_event(slave, I2C_SLAVE_READ_REQUESTED, &value);
1281 
1282 		/*
1283 		 * Disable slave TX config in case of I2C combined message
1284 		 * (I2C Write followed by I2C Read)
1285 		 */
1286 		mask = STM32F7_I2C_CR2_RELOAD;
1287 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR2, mask);
1288 		mask = STM32F7_I2C_CR1_SBC | STM32F7_I2C_CR1_RXIE |
1289 		       STM32F7_I2C_CR1_TCIE;
1290 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, mask);
1291 
1292 		/* Enable TX empty, STOP, NACK interrupts */
1293 		mask =  STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE |
1294 			STM32F7_I2C_CR1_TXIE;
1295 		stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
1296 
1297 		/* Write 1st data byte */
1298 		writel_relaxed(value, base + STM32F7_I2C_TXDR);
1299 	} else {
1300 		/* Notify i2c slave that new write transfer is starting */
1301 		i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value);
1302 
1303 		/* Set reload mode to be able to ACK/NACK each received byte */
1304 		mask = STM32F7_I2C_CR2_RELOAD;
1305 		stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask);
1306 
1307 		/*
1308 		 * Set STOP, NACK, RX empty and transfer complete interrupts.*
1309 		 * Set Slave Byte Control to be able to ACK/NACK each data
1310 		 * byte received
1311 		 */
1312 		mask =  STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE |
1313 			STM32F7_I2C_CR1_SBC | STM32F7_I2C_CR1_RXIE |
1314 			STM32F7_I2C_CR1_TCIE;
1315 		stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
1316 	}
1317 }
1318 
stm32f7_i2c_slave_addr(struct stm32f7_i2c_dev * i2c_dev)1319 static void stm32f7_i2c_slave_addr(struct stm32f7_i2c_dev *i2c_dev)
1320 {
1321 	void __iomem *base = i2c_dev->base;
1322 	u32 isr, addcode, dir, mask;
1323 	int i;
1324 
1325 	isr = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
1326 	addcode = STM32F7_I2C_ISR_ADDCODE_GET(isr);
1327 	dir = isr & STM32F7_I2C_ISR_DIR;
1328 
1329 	for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) {
1330 		if (stm32f7_i2c_is_addr_match(i2c_dev->slave[i], addcode)) {
1331 			i2c_dev->slave_running = i2c_dev->slave[i];
1332 			i2c_dev->slave_dir = dir;
1333 
1334 			/* Start I2C slave processing */
1335 			stm32f7_i2c_slave_start(i2c_dev);
1336 
1337 			/* Clear ADDR flag */
1338 			mask = STM32F7_I2C_ICR_ADDRCF;
1339 			writel_relaxed(mask, base + STM32F7_I2C_ICR);
1340 			break;
1341 		}
1342 	}
1343 }
1344 
stm32f7_i2c_get_slave_id(struct stm32f7_i2c_dev * i2c_dev,struct i2c_client * slave,int * id)1345 static int stm32f7_i2c_get_slave_id(struct stm32f7_i2c_dev *i2c_dev,
1346 				    struct i2c_client *slave, int *id)
1347 {
1348 	int i;
1349 
1350 	for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) {
1351 		if (i2c_dev->slave[i] == slave) {
1352 			*id = i;
1353 			return 0;
1354 		}
1355 	}
1356 
1357 	dev_err(i2c_dev->dev, "Slave 0x%x not registered\n", slave->addr);
1358 
1359 	return -ENODEV;
1360 }
1361 
stm32f7_i2c_get_free_slave_id(struct stm32f7_i2c_dev * i2c_dev,struct i2c_client * slave,int * id)1362 static int stm32f7_i2c_get_free_slave_id(struct stm32f7_i2c_dev *i2c_dev,
1363 					 struct i2c_client *slave, int *id)
1364 {
1365 	struct device *dev = i2c_dev->dev;
1366 	int i;
1367 
1368 	/*
1369 	 * slave[STM32F7_SLAVE_HOSTNOTIFY] support only SMBus Host address (0x8)
1370 	 * slave[STM32F7_SLAVE_7_10_BITS_ADDR] supports 7-bit and 10-bit slave address
1371 	 * slave[STM32F7_SLAVE_7_BITS_ADDR] supports 7-bit slave address only
1372 	 */
1373 	if (i2c_dev->smbus_mode && (slave->addr == 0x08)) {
1374 		if (i2c_dev->slave[STM32F7_SLAVE_HOSTNOTIFY])
1375 			goto fail;
1376 		*id = STM32F7_SLAVE_HOSTNOTIFY;
1377 		return 0;
1378 	}
1379 
1380 	for (i = STM32F7_I2C_MAX_SLAVE - 1; i > STM32F7_SLAVE_HOSTNOTIFY; i--) {
1381 		if ((i == STM32F7_SLAVE_7_BITS_ADDR) &&
1382 		    (slave->flags & I2C_CLIENT_TEN))
1383 			continue;
1384 		if (!i2c_dev->slave[i]) {
1385 			*id = i;
1386 			return 0;
1387 		}
1388 	}
1389 
1390 fail:
1391 	dev_err(dev, "Slave 0x%x could not be registered\n", slave->addr);
1392 
1393 	return -EINVAL;
1394 }
1395 
stm32f7_i2c_is_slave_registered(struct stm32f7_i2c_dev * i2c_dev)1396 static bool stm32f7_i2c_is_slave_registered(struct stm32f7_i2c_dev *i2c_dev)
1397 {
1398 	int i;
1399 
1400 	for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) {
1401 		if (i2c_dev->slave[i])
1402 			return true;
1403 	}
1404 
1405 	return false;
1406 }
1407 
stm32f7_i2c_is_slave_busy(struct stm32f7_i2c_dev * i2c_dev)1408 static bool stm32f7_i2c_is_slave_busy(struct stm32f7_i2c_dev *i2c_dev)
1409 {
1410 	int i, busy;
1411 
1412 	busy = 0;
1413 	for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) {
1414 		if (i2c_dev->slave[i])
1415 			busy++;
1416 	}
1417 
1418 	return i == busy;
1419 }
1420 
stm32f7_i2c_slave_isr_event(struct stm32f7_i2c_dev * i2c_dev)1421 static irqreturn_t stm32f7_i2c_slave_isr_event(struct stm32f7_i2c_dev *i2c_dev)
1422 {
1423 	void __iomem *base = i2c_dev->base;
1424 	u32 cr2, status, mask;
1425 	u8 val;
1426 	int ret;
1427 
1428 	status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
1429 
1430 	/* Slave transmitter mode */
1431 	if (status & STM32F7_I2C_ISR_TXIS) {
1432 		i2c_slave_event(i2c_dev->slave_running,
1433 				I2C_SLAVE_READ_PROCESSED,
1434 				&val);
1435 
1436 		/* Write data byte */
1437 		writel_relaxed(val, base + STM32F7_I2C_TXDR);
1438 	}
1439 
1440 	/* Transfer Complete Reload for Slave receiver mode */
1441 	if (status & STM32F7_I2C_ISR_TCR || status & STM32F7_I2C_ISR_RXNE) {
1442 		/*
1443 		 * Read data byte then set NBYTES to receive next byte or NACK
1444 		 * the current received byte
1445 		 */
1446 		val = readb_relaxed(i2c_dev->base + STM32F7_I2C_RXDR);
1447 		ret = i2c_slave_event(i2c_dev->slave_running,
1448 				      I2C_SLAVE_WRITE_RECEIVED,
1449 				      &val);
1450 		if (!ret) {
1451 			cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
1452 			cr2 |= STM32F7_I2C_CR2_NBYTES(1);
1453 			writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2);
1454 		} else {
1455 			mask = STM32F7_I2C_CR2_NACK;
1456 			stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask);
1457 		}
1458 	}
1459 
1460 	/* NACK received */
1461 	if (status & STM32F7_I2C_ISR_NACKF) {
1462 		dev_dbg(i2c_dev->dev, "<%s>: Receive NACK\n", __func__);
1463 		writel_relaxed(STM32F7_I2C_ICR_NACKCF, base + STM32F7_I2C_ICR);
1464 	}
1465 
1466 	/* STOP received */
1467 	if (status & STM32F7_I2C_ISR_STOPF) {
1468 		/* Disable interrupts */
1469 		stm32f7_i2c_disable_irq(i2c_dev, STM32F7_I2C_XFER_IRQ_MASK);
1470 
1471 		if (i2c_dev->slave_dir) {
1472 			/*
1473 			 * Flush TX buffer in order to not used the byte in
1474 			 * TXDR for the next transfer
1475 			 */
1476 			mask = STM32F7_I2C_ISR_TXE;
1477 			stm32f7_i2c_set_bits(base + STM32F7_I2C_ISR, mask);
1478 		}
1479 
1480 		/* Clear STOP flag */
1481 		writel_relaxed(STM32F7_I2C_ICR_STOPCF, base + STM32F7_I2C_ICR);
1482 
1483 		/* Notify i2c slave that a STOP flag has been detected */
1484 		i2c_slave_event(i2c_dev->slave_running, I2C_SLAVE_STOP, &val);
1485 
1486 		i2c_dev->slave_running = NULL;
1487 	}
1488 
1489 	/* Address match received */
1490 	if (status & STM32F7_I2C_ISR_ADDR)
1491 		stm32f7_i2c_slave_addr(i2c_dev);
1492 
1493 	return IRQ_HANDLED;
1494 }
1495 
stm32f7_i2c_isr_event(int irq,void * data)1496 static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data)
1497 {
1498 	struct stm32f7_i2c_dev *i2c_dev = data;
1499 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1500 	struct stm32_i2c_dma *dma = i2c_dev->dma;
1501 	void __iomem *base = i2c_dev->base;
1502 	u32 status, mask;
1503 	int ret = IRQ_HANDLED;
1504 
1505 	/* Check if the interrupt if for a slave device */
1506 	if (!i2c_dev->master_mode) {
1507 		ret = stm32f7_i2c_slave_isr_event(i2c_dev);
1508 		return ret;
1509 	}
1510 
1511 	status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
1512 
1513 	/* Tx empty */
1514 	if (status & STM32F7_I2C_ISR_TXIS)
1515 		stm32f7_i2c_write_tx_data(i2c_dev);
1516 
1517 	/* RX not empty */
1518 	if (status & STM32F7_I2C_ISR_RXNE)
1519 		stm32f7_i2c_read_rx_data(i2c_dev);
1520 
1521 	/* NACK received */
1522 	if (status & STM32F7_I2C_ISR_NACKF) {
1523 		dev_dbg(i2c_dev->dev, "<%s>: Receive NACK (addr %x)\n",
1524 			__func__, f7_msg->addr);
1525 		writel_relaxed(STM32F7_I2C_ICR_NACKCF, base + STM32F7_I2C_ICR);
1526 		if (i2c_dev->use_dma) {
1527 			stm32f7_i2c_disable_dma_req(i2c_dev);
1528 			dmaengine_terminate_async(dma->chan_using);
1529 		}
1530 		f7_msg->result = -ENXIO;
1531 	}
1532 
1533 	/* STOP detection flag */
1534 	if (status & STM32F7_I2C_ISR_STOPF) {
1535 		/* Disable interrupts */
1536 		if (stm32f7_i2c_is_slave_registered(i2c_dev))
1537 			mask = STM32F7_I2C_XFER_IRQ_MASK;
1538 		else
1539 			mask = STM32F7_I2C_ALL_IRQ_MASK;
1540 		stm32f7_i2c_disable_irq(i2c_dev, mask);
1541 
1542 		/* Clear STOP flag */
1543 		writel_relaxed(STM32F7_I2C_ICR_STOPCF, base + STM32F7_I2C_ICR);
1544 
1545 		if (i2c_dev->use_dma && !f7_msg->result) {
1546 			ret = IRQ_WAKE_THREAD;
1547 		} else {
1548 			i2c_dev->master_mode = false;
1549 			complete(&i2c_dev->complete);
1550 		}
1551 	}
1552 
1553 	/* Transfer complete */
1554 	if (status & STM32F7_I2C_ISR_TC) {
1555 		if (f7_msg->stop) {
1556 			mask = STM32F7_I2C_CR2_STOP;
1557 			stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask);
1558 		} else if (i2c_dev->use_dma && !f7_msg->result) {
1559 			ret = IRQ_WAKE_THREAD;
1560 		} else if (f7_msg->smbus) {
1561 			stm32f7_i2c_smbus_rep_start(i2c_dev);
1562 		} else {
1563 			i2c_dev->msg_id++;
1564 			i2c_dev->msg++;
1565 			stm32f7_i2c_xfer_msg(i2c_dev, i2c_dev->msg);
1566 		}
1567 	}
1568 
1569 	if (status & STM32F7_I2C_ISR_TCR) {
1570 		if (f7_msg->smbus)
1571 			stm32f7_i2c_smbus_reload(i2c_dev);
1572 		else
1573 			stm32f7_i2c_reload(i2c_dev);
1574 	}
1575 
1576 	return ret;
1577 }
1578 
stm32f7_i2c_isr_event_thread(int irq,void * data)1579 static irqreturn_t stm32f7_i2c_isr_event_thread(int irq, void *data)
1580 {
1581 	struct stm32f7_i2c_dev *i2c_dev = data;
1582 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1583 	struct stm32_i2c_dma *dma = i2c_dev->dma;
1584 	u32 status;
1585 	int ret;
1586 
1587 	/*
1588 	 * Wait for dma transfer completion before sending next message or
1589 	 * notity the end of xfer to the client
1590 	 */
1591 	ret = wait_for_completion_timeout(&i2c_dev->dma->dma_complete, HZ);
1592 	if (!ret) {
1593 		dev_dbg(i2c_dev->dev, "<%s>: Timed out\n", __func__);
1594 		stm32f7_i2c_disable_dma_req(i2c_dev);
1595 		dmaengine_terminate_async(dma->chan_using);
1596 		f7_msg->result = -ETIMEDOUT;
1597 	}
1598 
1599 	status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
1600 
1601 	if (status & STM32F7_I2C_ISR_TC) {
1602 		if (f7_msg->smbus) {
1603 			stm32f7_i2c_smbus_rep_start(i2c_dev);
1604 		} else {
1605 			i2c_dev->msg_id++;
1606 			i2c_dev->msg++;
1607 			stm32f7_i2c_xfer_msg(i2c_dev, i2c_dev->msg);
1608 		}
1609 	} else {
1610 		i2c_dev->master_mode = false;
1611 		complete(&i2c_dev->complete);
1612 	}
1613 
1614 	return IRQ_HANDLED;
1615 }
1616 
stm32f7_i2c_isr_error(int irq,void * data)1617 static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data)
1618 {
1619 	struct stm32f7_i2c_dev *i2c_dev = data;
1620 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1621 	void __iomem *base = i2c_dev->base;
1622 	struct device *dev = i2c_dev->dev;
1623 	struct stm32_i2c_dma *dma = i2c_dev->dma;
1624 	u32 status;
1625 
1626 	status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
1627 
1628 	/* Bus error */
1629 	if (status & STM32F7_I2C_ISR_BERR) {
1630 		dev_err(dev, "<%s>: Bus error accessing addr 0x%x\n",
1631 			__func__, f7_msg->addr);
1632 		writel_relaxed(STM32F7_I2C_ICR_BERRCF, base + STM32F7_I2C_ICR);
1633 		stm32f7_i2c_release_bus(&i2c_dev->adap);
1634 		f7_msg->result = -EIO;
1635 	}
1636 
1637 	/* Arbitration loss */
1638 	if (status & STM32F7_I2C_ISR_ARLO) {
1639 		dev_dbg(dev, "<%s>: Arbitration loss accessing addr 0x%x\n",
1640 			__func__, f7_msg->addr);
1641 		writel_relaxed(STM32F7_I2C_ICR_ARLOCF, base + STM32F7_I2C_ICR);
1642 		f7_msg->result = -EAGAIN;
1643 	}
1644 
1645 	if (status & STM32F7_I2C_ISR_PECERR) {
1646 		dev_err(dev, "<%s>: PEC error in reception accessing addr 0x%x\n",
1647 			__func__, f7_msg->addr);
1648 		writel_relaxed(STM32F7_I2C_ICR_PECCF, base + STM32F7_I2C_ICR);
1649 		f7_msg->result = -EINVAL;
1650 	}
1651 
1652 	if (status & STM32F7_I2C_ISR_ALERT) {
1653 		dev_dbg(dev, "<%s>: SMBus alert received\n", __func__);
1654 		writel_relaxed(STM32F7_I2C_ICR_ALERTCF, base + STM32F7_I2C_ICR);
1655 		i2c_handle_smbus_alert(i2c_dev->alert->ara);
1656 		return IRQ_HANDLED;
1657 	}
1658 
1659 	if (!i2c_dev->slave_running) {
1660 		u32 mask;
1661 		/* Disable interrupts */
1662 		if (stm32f7_i2c_is_slave_registered(i2c_dev))
1663 			mask = STM32F7_I2C_XFER_IRQ_MASK;
1664 		else
1665 			mask = STM32F7_I2C_ALL_IRQ_MASK;
1666 		stm32f7_i2c_disable_irq(i2c_dev, mask);
1667 	}
1668 
1669 	/* Disable dma */
1670 	if (i2c_dev->use_dma) {
1671 		stm32f7_i2c_disable_dma_req(i2c_dev);
1672 		dmaengine_terminate_async(dma->chan_using);
1673 	}
1674 
1675 	i2c_dev->master_mode = false;
1676 	complete(&i2c_dev->complete);
1677 
1678 	return IRQ_HANDLED;
1679 }
1680 
stm32f7_i2c_wait_polling(struct stm32f7_i2c_dev * i2c_dev)1681 static int stm32f7_i2c_wait_polling(struct stm32f7_i2c_dev *i2c_dev)
1682 {
1683 	ktime_t timeout = ktime_add_ms(ktime_get(), i2c_dev->adap.timeout);
1684 
1685 	while (ktime_compare(ktime_get(), timeout) < 0) {
1686 		udelay(5);
1687 		stm32f7_i2c_isr_event(0, i2c_dev);
1688 
1689 		if (completion_done(&i2c_dev->complete))
1690 			return 1;
1691 	}
1692 
1693 	return 0;
1694 }
1695 
stm32f7_i2c_xfer_core(struct i2c_adapter * i2c_adap,struct i2c_msg msgs[],int num)1696 static int stm32f7_i2c_xfer_core(struct i2c_adapter *i2c_adap,
1697 			    struct i2c_msg msgs[], int num)
1698 {
1699 	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap);
1700 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1701 	struct stm32_i2c_dma *dma = i2c_dev->dma;
1702 	unsigned long time_left;
1703 	int ret;
1704 
1705 	i2c_dev->msg = msgs;
1706 	i2c_dev->msg_num = num;
1707 	i2c_dev->msg_id = 0;
1708 	f7_msg->smbus = false;
1709 
1710 	ret = pm_runtime_resume_and_get(i2c_dev->dev);
1711 	if (ret < 0)
1712 		return ret;
1713 
1714 	ret = stm32f7_i2c_wait_free_bus(i2c_dev);
1715 	if (ret)
1716 		goto pm_free;
1717 
1718 	stm32f7_i2c_xfer_msg(i2c_dev, msgs);
1719 
1720 	if (!i2c_dev->atomic)
1721 		time_left = wait_for_completion_timeout(&i2c_dev->complete,
1722 							i2c_dev->adap.timeout);
1723 	else
1724 		time_left = stm32f7_i2c_wait_polling(i2c_dev);
1725 
1726 	ret = f7_msg->result;
1727 	if (ret) {
1728 		if (i2c_dev->use_dma)
1729 			dmaengine_synchronize(dma->chan_using);
1730 
1731 		/*
1732 		 * It is possible that some unsent data have already been
1733 		 * written into TXDR. To avoid sending old data in a
1734 		 * further transfer, flush TXDR in case of any error
1735 		 */
1736 		writel_relaxed(STM32F7_I2C_ISR_TXE,
1737 			       i2c_dev->base + STM32F7_I2C_ISR);
1738 		goto pm_free;
1739 	}
1740 
1741 	if (!time_left) {
1742 		dev_dbg(i2c_dev->dev, "Access to slave 0x%x timed out\n",
1743 			i2c_dev->msg->addr);
1744 		if (i2c_dev->use_dma)
1745 			dmaengine_terminate_sync(dma->chan_using);
1746 		stm32f7_i2c_wait_free_bus(i2c_dev);
1747 		ret = -ETIMEDOUT;
1748 	}
1749 
1750 pm_free:
1751 	pm_runtime_mark_last_busy(i2c_dev->dev);
1752 	pm_runtime_put_autosuspend(i2c_dev->dev);
1753 
1754 	return (ret < 0) ? ret : num;
1755 }
1756 
stm32f7_i2c_xfer(struct i2c_adapter * i2c_adap,struct i2c_msg msgs[],int num)1757 static int stm32f7_i2c_xfer(struct i2c_adapter *i2c_adap,
1758 			    struct i2c_msg msgs[], int num)
1759 {
1760 	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap);
1761 
1762 	i2c_dev->atomic = false;
1763 	return stm32f7_i2c_xfer_core(i2c_adap, msgs, num);
1764 }
1765 
stm32f7_i2c_xfer_atomic(struct i2c_adapter * i2c_adap,struct i2c_msg msgs[],int num)1766 static int stm32f7_i2c_xfer_atomic(struct i2c_adapter *i2c_adap,
1767 			    struct i2c_msg msgs[], int num)
1768 {
1769 	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap);
1770 
1771 	i2c_dev->atomic = true;
1772 	return stm32f7_i2c_xfer_core(i2c_adap, msgs, num);
1773 }
1774 
stm32f7_i2c_smbus_xfer(struct i2c_adapter * adapter,u16 addr,unsigned short flags,char read_write,u8 command,int size,union i2c_smbus_data * data)1775 static int stm32f7_i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
1776 				  unsigned short flags, char read_write,
1777 				  u8 command, int size,
1778 				  union i2c_smbus_data *data)
1779 {
1780 	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(adapter);
1781 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1782 	struct stm32_i2c_dma *dma = i2c_dev->dma;
1783 	struct device *dev = i2c_dev->dev;
1784 	unsigned long timeout;
1785 	int i, ret;
1786 
1787 	f7_msg->addr = addr;
1788 	f7_msg->size = size;
1789 	f7_msg->read_write = read_write;
1790 	f7_msg->smbus = true;
1791 
1792 	ret = pm_runtime_resume_and_get(dev);
1793 	if (ret < 0)
1794 		return ret;
1795 
1796 	ret = stm32f7_i2c_wait_free_bus(i2c_dev);
1797 	if (ret)
1798 		goto pm_free;
1799 
1800 	ret = stm32f7_i2c_smbus_xfer_msg(i2c_dev, flags, command, data);
1801 	if (ret)
1802 		goto pm_free;
1803 
1804 	timeout = wait_for_completion_timeout(&i2c_dev->complete,
1805 					      i2c_dev->adap.timeout);
1806 	ret = f7_msg->result;
1807 	if (ret) {
1808 		if (i2c_dev->use_dma)
1809 			dmaengine_synchronize(dma->chan_using);
1810 
1811 		/*
1812 		 * It is possible that some unsent data have already been
1813 		 * written into TXDR. To avoid sending old data in a
1814 		 * further transfer, flush TXDR in case of any error
1815 		 */
1816 		writel_relaxed(STM32F7_I2C_ISR_TXE,
1817 			       i2c_dev->base + STM32F7_I2C_ISR);
1818 		goto pm_free;
1819 	}
1820 
1821 	if (!timeout) {
1822 		dev_dbg(dev, "Access to slave 0x%x timed out\n", f7_msg->addr);
1823 		if (i2c_dev->use_dma)
1824 			dmaengine_terminate_sync(dma->chan_using);
1825 		stm32f7_i2c_wait_free_bus(i2c_dev);
1826 		ret = -ETIMEDOUT;
1827 		goto pm_free;
1828 	}
1829 
1830 	/* Check PEC */
1831 	if ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK && read_write) {
1832 		ret = stm32f7_i2c_smbus_check_pec(i2c_dev);
1833 		if (ret)
1834 			goto pm_free;
1835 	}
1836 
1837 	if (read_write && size != I2C_SMBUS_QUICK) {
1838 		switch (size) {
1839 		case I2C_SMBUS_BYTE:
1840 		case I2C_SMBUS_BYTE_DATA:
1841 			data->byte = f7_msg->smbus_buf[0];
1842 		break;
1843 		case I2C_SMBUS_WORD_DATA:
1844 		case I2C_SMBUS_PROC_CALL:
1845 			data->word = f7_msg->smbus_buf[0] |
1846 				(f7_msg->smbus_buf[1] << 8);
1847 		break;
1848 		case I2C_SMBUS_BLOCK_DATA:
1849 		case I2C_SMBUS_BLOCK_PROC_CALL:
1850 		for (i = 0; i <= f7_msg->smbus_buf[0]; i++)
1851 			data->block[i] = f7_msg->smbus_buf[i];
1852 		break;
1853 		default:
1854 			dev_err(dev, "Unsupported smbus transaction\n");
1855 			ret = -EINVAL;
1856 		}
1857 	}
1858 
1859 pm_free:
1860 	pm_runtime_mark_last_busy(dev);
1861 	pm_runtime_put_autosuspend(dev);
1862 	return ret;
1863 }
1864 
stm32f7_i2c_enable_wakeup(struct stm32f7_i2c_dev * i2c_dev,bool enable)1865 static void stm32f7_i2c_enable_wakeup(struct stm32f7_i2c_dev *i2c_dev,
1866 				      bool enable)
1867 {
1868 	void __iomem *base = i2c_dev->base;
1869 	u32 mask = STM32F7_I2C_CR1_WUPEN;
1870 
1871 	if (!i2c_dev->wakeup_src)
1872 		return;
1873 
1874 	if (enable) {
1875 		device_set_wakeup_enable(i2c_dev->dev, true);
1876 		stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
1877 	} else {
1878 		device_set_wakeup_enable(i2c_dev->dev, false);
1879 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, mask);
1880 	}
1881 }
1882 
stm32f7_i2c_reg_slave(struct i2c_client * slave)1883 static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
1884 {
1885 	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(slave->adapter);
1886 	void __iomem *base = i2c_dev->base;
1887 	struct device *dev = i2c_dev->dev;
1888 	u32 oar1, oar2, mask;
1889 	int id, ret;
1890 
1891 	if (slave->flags & I2C_CLIENT_PEC) {
1892 		dev_err(dev, "SMBus PEC not supported in slave mode\n");
1893 		return -EINVAL;
1894 	}
1895 
1896 	if (stm32f7_i2c_is_slave_busy(i2c_dev)) {
1897 		dev_err(dev, "Too much slave registered\n");
1898 		return -EBUSY;
1899 	}
1900 
1901 	ret = stm32f7_i2c_get_free_slave_id(i2c_dev, slave, &id);
1902 	if (ret)
1903 		return ret;
1904 
1905 	ret = pm_runtime_resume_and_get(dev);
1906 	if (ret < 0)
1907 		return ret;
1908 
1909 	if (!stm32f7_i2c_is_slave_registered(i2c_dev))
1910 		stm32f7_i2c_enable_wakeup(i2c_dev, true);
1911 
1912 	switch (id) {
1913 	case 0:
1914 		/* Slave SMBus Host */
1915 		i2c_dev->slave[id] = slave;
1916 		break;
1917 
1918 	case 1:
1919 		/* Configure Own Address 1 */
1920 		oar1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR1);
1921 		oar1 &= ~STM32F7_I2C_OAR1_MASK;
1922 		if (slave->flags & I2C_CLIENT_TEN) {
1923 			oar1 |= STM32F7_I2C_OAR1_OA1_10(slave->addr);
1924 			oar1 |= STM32F7_I2C_OAR1_OA1MODE;
1925 		} else {
1926 			oar1 |= STM32F7_I2C_OAR1_OA1_7(slave->addr);
1927 		}
1928 		oar1 |= STM32F7_I2C_OAR1_OA1EN;
1929 		i2c_dev->slave[id] = slave;
1930 		writel_relaxed(oar1, i2c_dev->base + STM32F7_I2C_OAR1);
1931 		break;
1932 
1933 	case 2:
1934 		/* Configure Own Address 2 */
1935 		oar2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR2);
1936 		oar2 &= ~STM32F7_I2C_OAR2_MASK;
1937 		if (slave->flags & I2C_CLIENT_TEN) {
1938 			ret = -EOPNOTSUPP;
1939 			goto pm_free;
1940 		}
1941 
1942 		oar2 |= STM32F7_I2C_OAR2_OA2_7(slave->addr);
1943 		oar2 |= STM32F7_I2C_OAR2_OA2EN;
1944 		i2c_dev->slave[id] = slave;
1945 		writel_relaxed(oar2, i2c_dev->base + STM32F7_I2C_OAR2);
1946 		break;
1947 
1948 	default:
1949 		dev_err(dev, "I2C slave id not supported\n");
1950 		ret = -ENODEV;
1951 		goto pm_free;
1952 	}
1953 
1954 	/* Enable ACK */
1955 	stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR2, STM32F7_I2C_CR2_NACK);
1956 
1957 	/* Enable Address match interrupt, error interrupt and enable I2C  */
1958 	mask = STM32F7_I2C_CR1_ADDRIE | STM32F7_I2C_CR1_ERRIE |
1959 		STM32F7_I2C_CR1_PE;
1960 	stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
1961 
1962 	ret = 0;
1963 pm_free:
1964 	if (!stm32f7_i2c_is_slave_registered(i2c_dev))
1965 		stm32f7_i2c_enable_wakeup(i2c_dev, false);
1966 
1967 	pm_runtime_mark_last_busy(dev);
1968 	pm_runtime_put_autosuspend(dev);
1969 
1970 	return ret;
1971 }
1972 
stm32f7_i2c_unreg_slave(struct i2c_client * slave)1973 static int stm32f7_i2c_unreg_slave(struct i2c_client *slave)
1974 {
1975 	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(slave->adapter);
1976 	void __iomem *base = i2c_dev->base;
1977 	u32 mask;
1978 	int id, ret;
1979 
1980 	ret = stm32f7_i2c_get_slave_id(i2c_dev, slave, &id);
1981 	if (ret)
1982 		return ret;
1983 
1984 	WARN_ON(!i2c_dev->slave[id]);
1985 
1986 	ret = pm_runtime_resume_and_get(i2c_dev->dev);
1987 	if (ret < 0)
1988 		return ret;
1989 
1990 	if (id == 1) {
1991 		mask = STM32F7_I2C_OAR1_OA1EN;
1992 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR1, mask);
1993 	} else if (id == 2) {
1994 		mask = STM32F7_I2C_OAR2_OA2EN;
1995 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR2, mask);
1996 	}
1997 
1998 	i2c_dev->slave[id] = NULL;
1999 
2000 	if (!stm32f7_i2c_is_slave_registered(i2c_dev)) {
2001 		stm32f7_i2c_disable_irq(i2c_dev, STM32F7_I2C_ALL_IRQ_MASK);
2002 		stm32f7_i2c_enable_wakeup(i2c_dev, false);
2003 	}
2004 
2005 	pm_runtime_mark_last_busy(i2c_dev->dev);
2006 	pm_runtime_put_autosuspend(i2c_dev->dev);
2007 
2008 	return 0;
2009 }
2010 
stm32f7_i2c_write_fm_plus_bits(struct stm32f7_i2c_dev * i2c_dev,bool enable)2011 static int stm32f7_i2c_write_fm_plus_bits(struct stm32f7_i2c_dev *i2c_dev,
2012 					  bool enable)
2013 {
2014 	int ret;
2015 
2016 	if (i2c_dev->bus_rate <= I2C_MAX_FAST_MODE_FREQ ||
2017 	    IS_ERR_OR_NULL(i2c_dev->regmap))
2018 		/* Optional */
2019 		return 0;
2020 
2021 	if (i2c_dev->fmp_sreg == i2c_dev->fmp_creg)
2022 		ret = regmap_update_bits(i2c_dev->regmap,
2023 					 i2c_dev->fmp_sreg,
2024 					 i2c_dev->fmp_mask,
2025 					 enable ? i2c_dev->fmp_mask : 0);
2026 	else
2027 		ret = regmap_write(i2c_dev->regmap,
2028 				   enable ? i2c_dev->fmp_sreg :
2029 					    i2c_dev->fmp_creg,
2030 				   i2c_dev->fmp_mask);
2031 
2032 	return ret;
2033 }
2034 
stm32f7_i2c_setup_fm_plus_bits(struct platform_device * pdev,struct stm32f7_i2c_dev * i2c_dev)2035 static int stm32f7_i2c_setup_fm_plus_bits(struct platform_device *pdev,
2036 					  struct stm32f7_i2c_dev *i2c_dev)
2037 {
2038 	struct device_node *np = pdev->dev.of_node;
2039 	int ret;
2040 
2041 	i2c_dev->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg-fmp");
2042 	if (IS_ERR(i2c_dev->regmap))
2043 		/* Optional */
2044 		return 0;
2045 
2046 	ret = of_property_read_u32_index(np, "st,syscfg-fmp", 1,
2047 					 &i2c_dev->fmp_sreg);
2048 	if (ret)
2049 		return ret;
2050 
2051 	i2c_dev->fmp_creg = i2c_dev->fmp_sreg +
2052 			       i2c_dev->setup.fmp_clr_offset;
2053 
2054 	return of_property_read_u32_index(np, "st,syscfg-fmp", 2,
2055 					  &i2c_dev->fmp_mask);
2056 }
2057 
stm32f7_i2c_enable_smbus_host(struct stm32f7_i2c_dev * i2c_dev)2058 static int stm32f7_i2c_enable_smbus_host(struct stm32f7_i2c_dev *i2c_dev)
2059 {
2060 	struct i2c_adapter *adap = &i2c_dev->adap;
2061 	void __iomem *base = i2c_dev->base;
2062 	struct i2c_client *client;
2063 
2064 	client = i2c_new_slave_host_notify_device(adap);
2065 	if (IS_ERR(client))
2066 		return PTR_ERR(client);
2067 
2068 	i2c_dev->host_notify_client = client;
2069 
2070 	/* Enable SMBus Host address */
2071 	stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, STM32F7_I2C_CR1_SMBHEN);
2072 
2073 	return 0;
2074 }
2075 
stm32f7_i2c_disable_smbus_host(struct stm32f7_i2c_dev * i2c_dev)2076 static void stm32f7_i2c_disable_smbus_host(struct stm32f7_i2c_dev *i2c_dev)
2077 {
2078 	void __iomem *base = i2c_dev->base;
2079 
2080 	if (i2c_dev->host_notify_client) {
2081 		/* Disable SMBus Host address */
2082 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1,
2083 				     STM32F7_I2C_CR1_SMBHEN);
2084 		i2c_free_slave_host_notify_device(i2c_dev->host_notify_client);
2085 	}
2086 }
2087 
stm32f7_i2c_enable_smbus_alert(struct stm32f7_i2c_dev * i2c_dev)2088 static int stm32f7_i2c_enable_smbus_alert(struct stm32f7_i2c_dev *i2c_dev)
2089 {
2090 	struct stm32f7_i2c_alert *alert;
2091 	struct i2c_adapter *adap = &i2c_dev->adap;
2092 	struct device *dev = i2c_dev->dev;
2093 	void __iomem *base = i2c_dev->base;
2094 
2095 	alert = devm_kzalloc(dev, sizeof(*alert), GFP_KERNEL);
2096 	if (!alert)
2097 		return -ENOMEM;
2098 
2099 	alert->ara = i2c_new_smbus_alert_device(adap, &alert->setup);
2100 	if (IS_ERR(alert->ara))
2101 		return PTR_ERR(alert->ara);
2102 
2103 	i2c_dev->alert = alert;
2104 
2105 	/* Enable SMBus Alert */
2106 	stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, STM32F7_I2C_CR1_ALERTEN);
2107 
2108 	return 0;
2109 }
2110 
stm32f7_i2c_disable_smbus_alert(struct stm32f7_i2c_dev * i2c_dev)2111 static void stm32f7_i2c_disable_smbus_alert(struct stm32f7_i2c_dev *i2c_dev)
2112 {
2113 	struct stm32f7_i2c_alert *alert = i2c_dev->alert;
2114 	void __iomem *base = i2c_dev->base;
2115 
2116 	if (alert) {
2117 		/* Disable SMBus Alert */
2118 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1,
2119 				     STM32F7_I2C_CR1_ALERTEN);
2120 		i2c_unregister_device(alert->ara);
2121 	}
2122 }
2123 
stm32f7_i2c_func(struct i2c_adapter * adap)2124 static u32 stm32f7_i2c_func(struct i2c_adapter *adap)
2125 {
2126 	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
2127 
2128 	u32 func = I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SLAVE |
2129 		   I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
2130 		   I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
2131 		   I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
2132 		   I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_PEC |
2133 		   I2C_FUNC_SMBUS_I2C_BLOCK;
2134 
2135 	if (i2c_dev->smbus_mode)
2136 		func |= I2C_FUNC_SMBUS_HOST_NOTIFY;
2137 
2138 	return func;
2139 }
2140 
2141 static const struct i2c_algorithm stm32f7_i2c_algo = {
2142 	.master_xfer = stm32f7_i2c_xfer,
2143 	.master_xfer_atomic = stm32f7_i2c_xfer_atomic,
2144 	.smbus_xfer = stm32f7_i2c_smbus_xfer,
2145 	.functionality = stm32f7_i2c_func,
2146 	.reg_slave = stm32f7_i2c_reg_slave,
2147 	.unreg_slave = stm32f7_i2c_unreg_slave,
2148 };
2149 
stm32f7_i2c_probe(struct platform_device * pdev)2150 static int stm32f7_i2c_probe(struct platform_device *pdev)
2151 {
2152 	struct stm32f7_i2c_dev *i2c_dev;
2153 	const struct stm32f7_i2c_setup *setup;
2154 	struct resource *res;
2155 	struct i2c_adapter *adap;
2156 	struct reset_control *rst;
2157 	dma_addr_t phy_addr;
2158 	int irq_error, irq_event, ret;
2159 
2160 	i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
2161 	if (!i2c_dev)
2162 		return -ENOMEM;
2163 
2164 	i2c_dev->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
2165 	if (IS_ERR(i2c_dev->base))
2166 		return PTR_ERR(i2c_dev->base);
2167 	phy_addr = (dma_addr_t)res->start;
2168 
2169 	irq_event = platform_get_irq(pdev, 0);
2170 	if (irq_event < 0)
2171 		return irq_event;
2172 
2173 	irq_error = platform_get_irq(pdev, 1);
2174 	if (irq_error < 0)
2175 		return irq_error;
2176 
2177 	i2c_dev->wakeup_src = of_property_read_bool(pdev->dev.of_node,
2178 						    "wakeup-source");
2179 
2180 	i2c_dev->clk = devm_clk_get(&pdev->dev, NULL);
2181 	if (IS_ERR(i2c_dev->clk))
2182 		return dev_err_probe(&pdev->dev, PTR_ERR(i2c_dev->clk),
2183 				     "Failed to get controller clock\n");
2184 
2185 	ret = clk_prepare_enable(i2c_dev->clk);
2186 	if (ret) {
2187 		dev_err(&pdev->dev, "Failed to prepare_enable clock\n");
2188 		return ret;
2189 	}
2190 
2191 	rst = devm_reset_control_get(&pdev->dev, NULL);
2192 	if (IS_ERR(rst)) {
2193 		ret = dev_err_probe(&pdev->dev, PTR_ERR(rst),
2194 				    "Error: Missing reset ctrl\n");
2195 		goto clk_free;
2196 	}
2197 	reset_control_assert(rst);
2198 	udelay(2);
2199 	reset_control_deassert(rst);
2200 
2201 	i2c_dev->dev = &pdev->dev;
2202 
2203 	ret = devm_request_threaded_irq(&pdev->dev, irq_event,
2204 					stm32f7_i2c_isr_event,
2205 					stm32f7_i2c_isr_event_thread,
2206 					IRQF_ONESHOT,
2207 					pdev->name, i2c_dev);
2208 	if (ret) {
2209 		dev_err(&pdev->dev, "Failed to request irq event %i\n",
2210 			irq_event);
2211 		goto clk_free;
2212 	}
2213 
2214 	ret = devm_request_irq(&pdev->dev, irq_error, stm32f7_i2c_isr_error, 0,
2215 			       pdev->name, i2c_dev);
2216 	if (ret) {
2217 		dev_err(&pdev->dev, "Failed to request irq error %i\n",
2218 			irq_error);
2219 		goto clk_free;
2220 	}
2221 
2222 	setup = of_device_get_match_data(&pdev->dev);
2223 	if (!setup) {
2224 		dev_err(&pdev->dev, "Can't get device data\n");
2225 		ret = -ENODEV;
2226 		goto clk_free;
2227 	}
2228 	i2c_dev->setup = *setup;
2229 
2230 	ret = stm32f7_i2c_setup_timing(i2c_dev, &i2c_dev->setup);
2231 	if (ret)
2232 		goto clk_free;
2233 
2234 	/* Setup Fast mode plus if necessary */
2235 	if (i2c_dev->bus_rate > I2C_MAX_FAST_MODE_FREQ) {
2236 		ret = stm32f7_i2c_setup_fm_plus_bits(pdev, i2c_dev);
2237 		if (ret)
2238 			goto clk_free;
2239 		ret = stm32f7_i2c_write_fm_plus_bits(i2c_dev, true);
2240 		if (ret)
2241 			goto clk_free;
2242 	}
2243 
2244 	adap = &i2c_dev->adap;
2245 	i2c_set_adapdata(adap, i2c_dev);
2246 	snprintf(adap->name, sizeof(adap->name), "STM32F7 I2C(%pa)",
2247 		 &res->start);
2248 	adap->owner = THIS_MODULE;
2249 	adap->timeout = 2 * HZ;
2250 	adap->retries = 3;
2251 	adap->algo = &stm32f7_i2c_algo;
2252 	adap->dev.parent = &pdev->dev;
2253 	adap->dev.of_node = pdev->dev.of_node;
2254 
2255 	init_completion(&i2c_dev->complete);
2256 
2257 	/* Init DMA config if supported */
2258 	i2c_dev->dma = stm32_i2c_dma_request(i2c_dev->dev, phy_addr,
2259 					     STM32F7_I2C_TXDR,
2260 					     STM32F7_I2C_RXDR);
2261 	if (IS_ERR(i2c_dev->dma)) {
2262 		ret = PTR_ERR(i2c_dev->dma);
2263 		/* DMA support is optional, only report other errors */
2264 		if (ret != -ENODEV)
2265 			goto fmp_clear;
2266 		dev_dbg(i2c_dev->dev, "No DMA option: fallback using interrupts\n");
2267 		i2c_dev->dma = NULL;
2268 	}
2269 
2270 	if (i2c_dev->wakeup_src) {
2271 		device_set_wakeup_capable(i2c_dev->dev, true);
2272 
2273 		ret = dev_pm_set_wake_irq(i2c_dev->dev, irq_event);
2274 		if (ret) {
2275 			dev_err(i2c_dev->dev, "Failed to set wake up irq\n");
2276 			goto clr_wakeup_capable;
2277 		}
2278 	}
2279 
2280 	platform_set_drvdata(pdev, i2c_dev);
2281 
2282 	pm_runtime_set_autosuspend_delay(i2c_dev->dev,
2283 					 STM32F7_AUTOSUSPEND_DELAY);
2284 	pm_runtime_use_autosuspend(i2c_dev->dev);
2285 	pm_runtime_set_active(i2c_dev->dev);
2286 	pm_runtime_enable(i2c_dev->dev);
2287 
2288 	pm_runtime_get_noresume(&pdev->dev);
2289 
2290 	stm32f7_i2c_hw_config(i2c_dev);
2291 
2292 	i2c_dev->smbus_mode = of_property_read_bool(pdev->dev.of_node, "smbus");
2293 
2294 	ret = i2c_add_adapter(adap);
2295 	if (ret)
2296 		goto pm_disable;
2297 
2298 	if (i2c_dev->smbus_mode) {
2299 		ret = stm32f7_i2c_enable_smbus_host(i2c_dev);
2300 		if (ret) {
2301 			dev_err(i2c_dev->dev,
2302 				"failed to enable SMBus Host-Notify protocol (%d)\n",
2303 				ret);
2304 			goto i2c_adapter_remove;
2305 		}
2306 	}
2307 
2308 	if (of_property_read_bool(pdev->dev.of_node, "smbus-alert")) {
2309 		ret = stm32f7_i2c_enable_smbus_alert(i2c_dev);
2310 		if (ret) {
2311 			dev_err(i2c_dev->dev,
2312 				"failed to enable SMBus alert protocol (%d)\n",
2313 				ret);
2314 			goto i2c_disable_smbus_host;
2315 		}
2316 	}
2317 
2318 	dev_info(i2c_dev->dev, "STM32F7 I2C-%d bus adapter\n", adap->nr);
2319 
2320 	pm_runtime_mark_last_busy(i2c_dev->dev);
2321 	pm_runtime_put_autosuspend(i2c_dev->dev);
2322 
2323 	return 0;
2324 
2325 i2c_disable_smbus_host:
2326 	stm32f7_i2c_disable_smbus_host(i2c_dev);
2327 
2328 i2c_adapter_remove:
2329 	i2c_del_adapter(adap);
2330 
2331 pm_disable:
2332 	pm_runtime_put_noidle(i2c_dev->dev);
2333 	pm_runtime_disable(i2c_dev->dev);
2334 	pm_runtime_set_suspended(i2c_dev->dev);
2335 	pm_runtime_dont_use_autosuspend(i2c_dev->dev);
2336 
2337 	if (i2c_dev->wakeup_src)
2338 		dev_pm_clear_wake_irq(i2c_dev->dev);
2339 
2340 clr_wakeup_capable:
2341 	if (i2c_dev->wakeup_src)
2342 		device_set_wakeup_capable(i2c_dev->dev, false);
2343 
2344 	if (i2c_dev->dma) {
2345 		stm32_i2c_dma_free(i2c_dev->dma);
2346 		i2c_dev->dma = NULL;
2347 	}
2348 
2349 fmp_clear:
2350 	stm32f7_i2c_write_fm_plus_bits(i2c_dev, false);
2351 
2352 clk_free:
2353 	clk_disable_unprepare(i2c_dev->clk);
2354 
2355 	return ret;
2356 }
2357 
stm32f7_i2c_remove(struct platform_device * pdev)2358 static void stm32f7_i2c_remove(struct platform_device *pdev)
2359 {
2360 	struct stm32f7_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
2361 
2362 	stm32f7_i2c_disable_smbus_alert(i2c_dev);
2363 	stm32f7_i2c_disable_smbus_host(i2c_dev);
2364 
2365 	i2c_del_adapter(&i2c_dev->adap);
2366 	pm_runtime_get_sync(i2c_dev->dev);
2367 
2368 	if (i2c_dev->wakeup_src) {
2369 		dev_pm_clear_wake_irq(i2c_dev->dev);
2370 		/*
2371 		 * enforce that wakeup is disabled and that the device
2372 		 * is marked as non wakeup capable
2373 		 */
2374 		device_init_wakeup(i2c_dev->dev, false);
2375 	}
2376 
2377 	pm_runtime_put_noidle(i2c_dev->dev);
2378 	pm_runtime_disable(i2c_dev->dev);
2379 	pm_runtime_set_suspended(i2c_dev->dev);
2380 	pm_runtime_dont_use_autosuspend(i2c_dev->dev);
2381 
2382 	if (i2c_dev->dma) {
2383 		stm32_i2c_dma_free(i2c_dev->dma);
2384 		i2c_dev->dma = NULL;
2385 	}
2386 
2387 	stm32f7_i2c_write_fm_plus_bits(i2c_dev, false);
2388 
2389 	clk_disable_unprepare(i2c_dev->clk);
2390 }
2391 
stm32f7_i2c_runtime_suspend(struct device * dev)2392 static int __maybe_unused stm32f7_i2c_runtime_suspend(struct device *dev)
2393 {
2394 	struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
2395 
2396 	if (!stm32f7_i2c_is_slave_registered(i2c_dev))
2397 		clk_disable(i2c_dev->clk);
2398 
2399 	return 0;
2400 }
2401 
stm32f7_i2c_runtime_resume(struct device * dev)2402 static int __maybe_unused stm32f7_i2c_runtime_resume(struct device *dev)
2403 {
2404 	struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
2405 	int ret;
2406 
2407 	if (!stm32f7_i2c_is_slave_registered(i2c_dev)) {
2408 		ret = clk_enable(i2c_dev->clk);
2409 		if (ret) {
2410 			dev_err(dev, "failed to enable clock\n");
2411 			return ret;
2412 		}
2413 	}
2414 
2415 	return 0;
2416 }
2417 
stm32f7_i2c_regs_backup(struct stm32f7_i2c_dev * i2c_dev)2418 static int __maybe_unused stm32f7_i2c_regs_backup(struct stm32f7_i2c_dev *i2c_dev)
2419 {
2420 	int ret;
2421 	struct stm32f7_i2c_regs *backup_regs = &i2c_dev->backup_regs;
2422 
2423 	ret = pm_runtime_resume_and_get(i2c_dev->dev);
2424 	if (ret < 0)
2425 		return ret;
2426 
2427 	backup_regs->cr1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR1);
2428 	backup_regs->cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
2429 	backup_regs->oar1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR1);
2430 	backup_regs->oar2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR2);
2431 	backup_regs->tmgr = readl_relaxed(i2c_dev->base + STM32F7_I2C_TIMINGR);
2432 	stm32f7_i2c_write_fm_plus_bits(i2c_dev, false);
2433 
2434 	pm_runtime_put_sync(i2c_dev->dev);
2435 
2436 	return ret;
2437 }
2438 
stm32f7_i2c_regs_restore(struct stm32f7_i2c_dev * i2c_dev)2439 static int __maybe_unused stm32f7_i2c_regs_restore(struct stm32f7_i2c_dev *i2c_dev)
2440 {
2441 	u32 cr1;
2442 	int ret;
2443 	struct stm32f7_i2c_regs *backup_regs = &i2c_dev->backup_regs;
2444 
2445 	ret = pm_runtime_resume_and_get(i2c_dev->dev);
2446 	if (ret < 0)
2447 		return ret;
2448 
2449 	cr1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR1);
2450 	if (cr1 & STM32F7_I2C_CR1_PE)
2451 		stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1,
2452 				     STM32F7_I2C_CR1_PE);
2453 
2454 	writel_relaxed(backup_regs->tmgr, i2c_dev->base + STM32F7_I2C_TIMINGR);
2455 	writel_relaxed(backup_regs->cr1 & ~STM32F7_I2C_CR1_PE,
2456 		       i2c_dev->base + STM32F7_I2C_CR1);
2457 	if (backup_regs->cr1 & STM32F7_I2C_CR1_PE)
2458 		stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,
2459 				     STM32F7_I2C_CR1_PE);
2460 	writel_relaxed(backup_regs->cr2, i2c_dev->base + STM32F7_I2C_CR2);
2461 	writel_relaxed(backup_regs->oar1, i2c_dev->base + STM32F7_I2C_OAR1);
2462 	writel_relaxed(backup_regs->oar2, i2c_dev->base + STM32F7_I2C_OAR2);
2463 	stm32f7_i2c_write_fm_plus_bits(i2c_dev, true);
2464 
2465 	pm_runtime_put_sync(i2c_dev->dev);
2466 
2467 	return ret;
2468 }
2469 
stm32f7_i2c_suspend(struct device * dev)2470 static int __maybe_unused stm32f7_i2c_suspend(struct device *dev)
2471 {
2472 	struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
2473 	int ret;
2474 
2475 	i2c_mark_adapter_suspended(&i2c_dev->adap);
2476 
2477 	if (!device_may_wakeup(dev) && !device_wakeup_path(dev)) {
2478 		ret = stm32f7_i2c_regs_backup(i2c_dev);
2479 		if (ret < 0) {
2480 			i2c_mark_adapter_resumed(&i2c_dev->adap);
2481 			return ret;
2482 		}
2483 
2484 		pinctrl_pm_select_sleep_state(dev);
2485 		pm_runtime_force_suspend(dev);
2486 	}
2487 
2488 	return 0;
2489 }
2490 
stm32f7_i2c_resume(struct device * dev)2491 static int __maybe_unused stm32f7_i2c_resume(struct device *dev)
2492 {
2493 	struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
2494 	int ret;
2495 
2496 	if (!device_may_wakeup(dev) && !device_wakeup_path(dev)) {
2497 		ret = pm_runtime_force_resume(dev);
2498 		if (ret < 0)
2499 			return ret;
2500 		pinctrl_pm_select_default_state(dev);
2501 
2502 		ret = stm32f7_i2c_regs_restore(i2c_dev);
2503 		if (ret < 0)
2504 			return ret;
2505 	}
2506 
2507 	i2c_mark_adapter_resumed(&i2c_dev->adap);
2508 
2509 	return 0;
2510 }
2511 
2512 static const struct dev_pm_ops stm32f7_i2c_pm_ops = {
2513 	SET_RUNTIME_PM_OPS(stm32f7_i2c_runtime_suspend,
2514 			   stm32f7_i2c_runtime_resume, NULL)
2515 	SET_SYSTEM_SLEEP_PM_OPS(stm32f7_i2c_suspend, stm32f7_i2c_resume)
2516 };
2517 
2518 static const struct of_device_id stm32f7_i2c_match[] = {
2519 	{ .compatible = "st,stm32f7-i2c", .data = &stm32f7_setup},
2520 	{ .compatible = "st,stm32mp15-i2c", .data = &stm32mp15_setup},
2521 	{ .compatible = "st,stm32mp13-i2c", .data = &stm32mp13_setup},
2522 	{},
2523 };
2524 MODULE_DEVICE_TABLE(of, stm32f7_i2c_match);
2525 
2526 static struct platform_driver stm32f7_i2c_driver = {
2527 	.driver = {
2528 		.name = "stm32f7-i2c",
2529 		.of_match_table = stm32f7_i2c_match,
2530 		.pm = &stm32f7_i2c_pm_ops,
2531 	},
2532 	.probe = stm32f7_i2c_probe,
2533 	.remove_new = stm32f7_i2c_remove,
2534 };
2535 
2536 module_platform_driver(stm32f7_i2c_driver);
2537 
2538 MODULE_AUTHOR("M'boumba Cedric Madianga <cedric.madianga@gmail.com>");
2539 MODULE_DESCRIPTION("STMicroelectronics STM32F7 I2C driver");
2540 MODULE_LICENSE("GPL v2");
2541