xref: /openbmc/linux/drivers/i2c/busses/i2c-stm32f7.c (revision 82df5b73)
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/interrupt.h>
22 #include <linux/io.h>
23 #include <linux/iopoll.h>
24 #include <linux/mfd/syscon.h>
25 #include <linux/module.h>
26 #include <linux/of.h>
27 #include <linux/of_address.h>
28 #include <linux/of_platform.h>
29 #include <linux/platform_device.h>
30 #include <linux/pinctrl/consumer.h>
31 #include <linux/pm_runtime.h>
32 #include <linux/pm_wakeirq.h>
33 #include <linux/regmap.h>
34 #include <linux/reset.h>
35 #include <linux/slab.h>
36 
37 #include "i2c-stm32.h"
38 
39 /* STM32F7 I2C registers */
40 #define STM32F7_I2C_CR1				0x00
41 #define STM32F7_I2C_CR2				0x04
42 #define STM32F7_I2C_OAR1			0x08
43 #define STM32F7_I2C_OAR2			0x0C
44 #define STM32F7_I2C_PECR			0x20
45 #define STM32F7_I2C_TIMINGR			0x10
46 #define STM32F7_I2C_ISR				0x18
47 #define STM32F7_I2C_ICR				0x1C
48 #define STM32F7_I2C_RXDR			0x24
49 #define STM32F7_I2C_TXDR			0x28
50 
51 /* STM32F7 I2C control 1 */
52 #define STM32F7_I2C_CR1_PECEN			BIT(23)
53 #define STM32F7_I2C_CR1_WUPEN			BIT(18)
54 #define STM32F7_I2C_CR1_SBC			BIT(16)
55 #define STM32F7_I2C_CR1_RXDMAEN			BIT(15)
56 #define STM32F7_I2C_CR1_TXDMAEN			BIT(14)
57 #define STM32F7_I2C_CR1_ANFOFF			BIT(12)
58 #define STM32F7_I2C_CR1_ERRIE			BIT(7)
59 #define STM32F7_I2C_CR1_TCIE			BIT(6)
60 #define STM32F7_I2C_CR1_STOPIE			BIT(5)
61 #define STM32F7_I2C_CR1_NACKIE			BIT(4)
62 #define STM32F7_I2C_CR1_ADDRIE			BIT(3)
63 #define STM32F7_I2C_CR1_RXIE			BIT(2)
64 #define STM32F7_I2C_CR1_TXIE			BIT(1)
65 #define STM32F7_I2C_CR1_PE			BIT(0)
66 #define STM32F7_I2C_ALL_IRQ_MASK		(STM32F7_I2C_CR1_ERRIE \
67 						| STM32F7_I2C_CR1_TCIE \
68 						| STM32F7_I2C_CR1_STOPIE \
69 						| STM32F7_I2C_CR1_NACKIE \
70 						| STM32F7_I2C_CR1_RXIE \
71 						| STM32F7_I2C_CR1_TXIE)
72 #define STM32F7_I2C_XFER_IRQ_MASK		(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 
78 /* STM32F7 I2C control 2 */
79 #define STM32F7_I2C_CR2_PECBYTE			BIT(26)
80 #define STM32F7_I2C_CR2_RELOAD			BIT(24)
81 #define STM32F7_I2C_CR2_NBYTES_MASK		GENMASK(23, 16)
82 #define STM32F7_I2C_CR2_NBYTES(n)		(((n) & 0xff) << 16)
83 #define STM32F7_I2C_CR2_NACK			BIT(15)
84 #define STM32F7_I2C_CR2_STOP			BIT(14)
85 #define STM32F7_I2C_CR2_START			BIT(13)
86 #define STM32F7_I2C_CR2_HEAD10R			BIT(12)
87 #define STM32F7_I2C_CR2_ADD10			BIT(11)
88 #define STM32F7_I2C_CR2_RD_WRN			BIT(10)
89 #define STM32F7_I2C_CR2_SADD10_MASK		GENMASK(9, 0)
90 #define STM32F7_I2C_CR2_SADD10(n)		(((n) & \
91 						STM32F7_I2C_CR2_SADD10_MASK))
92 #define STM32F7_I2C_CR2_SADD7_MASK		GENMASK(7, 1)
93 #define STM32F7_I2C_CR2_SADD7(n)		(((n) & 0x7f) << 1)
94 
95 /* STM32F7 I2C Own Address 1 */
96 #define STM32F7_I2C_OAR1_OA1EN			BIT(15)
97 #define STM32F7_I2C_OAR1_OA1MODE		BIT(10)
98 #define STM32F7_I2C_OAR1_OA1_10_MASK		GENMASK(9, 0)
99 #define STM32F7_I2C_OAR1_OA1_10(n)		(((n) & \
100 						STM32F7_I2C_OAR1_OA1_10_MASK))
101 #define STM32F7_I2C_OAR1_OA1_7_MASK		GENMASK(7, 1)
102 #define STM32F7_I2C_OAR1_OA1_7(n)		(((n) & 0x7f) << 1)
103 #define STM32F7_I2C_OAR1_MASK			(STM32F7_I2C_OAR1_OA1_7_MASK \
104 						| STM32F7_I2C_OAR1_OA1_10_MASK \
105 						| STM32F7_I2C_OAR1_OA1EN \
106 						| STM32F7_I2C_OAR1_OA1MODE)
107 
108 /* STM32F7 I2C Own Address 2 */
109 #define STM32F7_I2C_OAR2_OA2EN			BIT(15)
110 #define STM32F7_I2C_OAR2_OA2MSK_MASK		GENMASK(10, 8)
111 #define STM32F7_I2C_OAR2_OA2MSK(n)		(((n) & 0x7) << 8)
112 #define STM32F7_I2C_OAR2_OA2_7_MASK		GENMASK(7, 1)
113 #define STM32F7_I2C_OAR2_OA2_7(n)		(((n) & 0x7f) << 1)
114 #define STM32F7_I2C_OAR2_MASK			(STM32F7_I2C_OAR2_OA2MSK_MASK \
115 						| STM32F7_I2C_OAR2_OA2_7_MASK \
116 						| STM32F7_I2C_OAR2_OA2EN)
117 
118 /* STM32F7 I2C Interrupt Status */
119 #define STM32F7_I2C_ISR_ADDCODE_MASK		GENMASK(23, 17)
120 #define STM32F7_I2C_ISR_ADDCODE_GET(n) \
121 				(((n) & STM32F7_I2C_ISR_ADDCODE_MASK) >> 17)
122 #define STM32F7_I2C_ISR_DIR			BIT(16)
123 #define STM32F7_I2C_ISR_BUSY			BIT(15)
124 #define STM32F7_I2C_ISR_PECERR			BIT(11)
125 #define STM32F7_I2C_ISR_ARLO			BIT(9)
126 #define STM32F7_I2C_ISR_BERR			BIT(8)
127 #define STM32F7_I2C_ISR_TCR			BIT(7)
128 #define STM32F7_I2C_ISR_TC			BIT(6)
129 #define STM32F7_I2C_ISR_STOPF			BIT(5)
130 #define STM32F7_I2C_ISR_NACKF			BIT(4)
131 #define STM32F7_I2C_ISR_ADDR			BIT(3)
132 #define STM32F7_I2C_ISR_RXNE			BIT(2)
133 #define STM32F7_I2C_ISR_TXIS			BIT(1)
134 #define STM32F7_I2C_ISR_TXE			BIT(0)
135 
136 /* STM32F7 I2C Interrupt Clear */
137 #define STM32F7_I2C_ICR_PECCF			BIT(11)
138 #define STM32F7_I2C_ICR_ARLOCF			BIT(9)
139 #define STM32F7_I2C_ICR_BERRCF			BIT(8)
140 #define STM32F7_I2C_ICR_STOPCF			BIT(5)
141 #define STM32F7_I2C_ICR_NACKCF			BIT(4)
142 #define STM32F7_I2C_ICR_ADDRCF			BIT(3)
143 
144 /* STM32F7 I2C Timing */
145 #define STM32F7_I2C_TIMINGR_PRESC(n)		(((n) & 0xf) << 28)
146 #define STM32F7_I2C_TIMINGR_SCLDEL(n)		(((n) & 0xf) << 20)
147 #define STM32F7_I2C_TIMINGR_SDADEL(n)		(((n) & 0xf) << 16)
148 #define STM32F7_I2C_TIMINGR_SCLH(n)		(((n) & 0xff) << 8)
149 #define STM32F7_I2C_TIMINGR_SCLL(n)		((n) & 0xff)
150 
151 #define STM32F7_I2C_MAX_LEN			0xff
152 #define STM32F7_I2C_DMA_LEN_MIN			0x16
153 #define STM32F7_I2C_MAX_SLAVE			0x2
154 
155 #define STM32F7_I2C_DNF_DEFAULT			0
156 #define STM32F7_I2C_DNF_MAX			16
157 
158 #define STM32F7_I2C_ANALOG_FILTER_ENABLE	1
159 #define STM32F7_I2C_ANALOG_FILTER_DELAY_MIN	50	/* ns */
160 #define STM32F7_I2C_ANALOG_FILTER_DELAY_MAX	260	/* ns */
161 
162 #define STM32F7_I2C_RISE_TIME_DEFAULT		25	/* ns */
163 #define STM32F7_I2C_FALL_TIME_DEFAULT		10	/* ns */
164 
165 #define STM32F7_PRESC_MAX			BIT(4)
166 #define STM32F7_SCLDEL_MAX			BIT(4)
167 #define STM32F7_SDADEL_MAX			BIT(4)
168 #define STM32F7_SCLH_MAX			BIT(8)
169 #define STM32F7_SCLL_MAX			BIT(8)
170 
171 #define STM32F7_AUTOSUSPEND_DELAY		(HZ / 100)
172 
173 /**
174  * struct stm32f7_i2c_regs - i2c f7 registers backup
175  * @cr1: Control register 1
176  * @cr2: Control register 2
177  * @oar1: Own address 1 register
178  * @oar2: Own address 2 register
179  * @tmgr: Timing register
180  */
181 struct stm32f7_i2c_regs {
182 	u32 cr1;
183 	u32 cr2;
184 	u32 oar1;
185 	u32 oar2;
186 	u32 tmgr;
187 };
188 
189 /**
190  * struct stm32f7_i2c_spec - private i2c specification timing
191  * @rate: I2C bus speed (Hz)
192  * @fall_max: Max fall time of both SDA and SCL signals (ns)
193  * @rise_max: Max rise time of both SDA and SCL signals (ns)
194  * @hddat_min: Min data hold time (ns)
195  * @vddat_max: Max data valid time (ns)
196  * @sudat_min: Min data setup time (ns)
197  * @l_min: Min low period of the SCL clock (ns)
198  * @h_min: Min high period of the SCL clock (ns)
199  */
200 struct stm32f7_i2c_spec {
201 	u32 rate;
202 	u32 fall_max;
203 	u32 rise_max;
204 	u32 hddat_min;
205 	u32 vddat_max;
206 	u32 sudat_min;
207 	u32 l_min;
208 	u32 h_min;
209 };
210 
211 /**
212  * struct stm32f7_i2c_setup - private I2C timing setup parameters
213  * @speed_freq: I2C speed frequency  (Hz)
214  * @clock_src: I2C clock source frequency (Hz)
215  * @rise_time: Rise time (ns)
216  * @fall_time: Fall time (ns)
217  * @dnf: Digital filter coefficient (0-16)
218  * @analog_filter: Analog filter delay (On/Off)
219  * @fmp_clr_offset: Fast Mode Plus clear register offset from set register
220  */
221 struct stm32f7_i2c_setup {
222 	u32 speed_freq;
223 	u32 clock_src;
224 	u32 rise_time;
225 	u32 fall_time;
226 	u8 dnf;
227 	bool analog_filter;
228 	u32 fmp_clr_offset;
229 };
230 
231 /**
232  * struct stm32f7_i2c_timings - private I2C output parameters
233  * @node: List entry
234  * @presc: Prescaler value
235  * @scldel: Data setup time
236  * @sdadel: Data hold time
237  * @sclh: SCL high period (master mode)
238  * @scll: SCL low period (master mode)
239  */
240 struct stm32f7_i2c_timings {
241 	struct list_head node;
242 	u8 presc;
243 	u8 scldel;
244 	u8 sdadel;
245 	u8 sclh;
246 	u8 scll;
247 };
248 
249 /**
250  * struct stm32f7_i2c_msg - client specific data
251  * @addr: 8-bit or 10-bit slave addr, including r/w bit
252  * @count: number of bytes to be transferred
253  * @buf: data buffer
254  * @result: result of the transfer
255  * @stop: last I2C msg to be sent, i.e. STOP to be generated
256  * @smbus: boolean to know if the I2C IP is used in SMBus mode
257  * @size: type of SMBus protocol
258  * @read_write: direction of SMBus protocol
259  * SMBus block read and SMBus block write - block read process call protocols
260  * @smbus_buf: buffer to be used for SMBus protocol transfer. It will
261  * contain a maximum of 32 bytes of data + byte command + byte count + PEC
262  * This buffer has to be 32-bit aligned to be compliant with memory address
263  * register in DMA mode.
264  */
265 struct stm32f7_i2c_msg {
266 	u16 addr;
267 	u32 count;
268 	u8 *buf;
269 	int result;
270 	bool stop;
271 	bool smbus;
272 	int size;
273 	char read_write;
274 	u8 smbus_buf[I2C_SMBUS_BLOCK_MAX + 3] __aligned(4);
275 };
276 
277 /**
278  * struct stm32f7_i2c_dev - private data of the controller
279  * @adap: I2C adapter for this controller
280  * @dev: device for this controller
281  * @base: virtual memory area
282  * @complete: completion of I2C message
283  * @clk: hw i2c clock
284  * @bus_rate: I2C clock frequency of the controller
285  * @msg: Pointer to data to be written
286  * @msg_num: number of I2C messages to be executed
287  * @msg_id: message identifiant
288  * @f7_msg: customized i2c msg for driver usage
289  * @setup: I2C timing input setup
290  * @timing: I2C computed timings
291  * @slave: list of slave devices registered on the I2C bus
292  * @slave_running: slave device currently used
293  * @backup_regs: backup of i2c controller registers (for suspend/resume)
294  * @slave_dir: transfer direction for the current slave device
295  * @master_mode: boolean to know in which mode the I2C is running (master or
296  * slave)
297  * @dma: dma data
298  * @use_dma: boolean to know if dma is used in the current transfer
299  * @regmap: holds SYSCFG phandle for Fast Mode Plus bits
300  * @fmp_sreg: register address for setting Fast Mode Plus bits
301  * @fmp_creg: register address for clearing Fast Mode Plus bits
302  * @fmp_mask: mask for Fast Mode Plus bits in set register
303  * @wakeup_src: boolean to know if the device is a wakeup source
304  */
305 struct stm32f7_i2c_dev {
306 	struct i2c_adapter adap;
307 	struct device *dev;
308 	void __iomem *base;
309 	struct completion complete;
310 	struct clk *clk;
311 	unsigned int bus_rate;
312 	struct i2c_msg *msg;
313 	unsigned int msg_num;
314 	unsigned int msg_id;
315 	struct stm32f7_i2c_msg f7_msg;
316 	struct stm32f7_i2c_setup setup;
317 	struct stm32f7_i2c_timings timing;
318 	struct i2c_client *slave[STM32F7_I2C_MAX_SLAVE];
319 	struct i2c_client *slave_running;
320 	struct stm32f7_i2c_regs backup_regs;
321 	u32 slave_dir;
322 	bool master_mode;
323 	struct stm32_i2c_dma *dma;
324 	bool use_dma;
325 	struct regmap *regmap;
326 	u32 fmp_sreg;
327 	u32 fmp_creg;
328 	u32 fmp_mask;
329 	bool wakeup_src;
330 };
331 
332 /*
333  * All these values are coming from I2C Specification, Version 6.0, 4th of
334  * April 2014.
335  *
336  * Table10. Characteristics of the SDA and SCL bus lines for Standard, Fast,
337  * and Fast-mode Plus I2C-bus devices
338  */
339 static struct stm32f7_i2c_spec stm32f7_i2c_specs[] = {
340 	{
341 		.rate = I2C_MAX_STANDARD_MODE_FREQ,
342 		.fall_max = 300,
343 		.rise_max = 1000,
344 		.hddat_min = 0,
345 		.vddat_max = 3450,
346 		.sudat_min = 250,
347 		.l_min = 4700,
348 		.h_min = 4000,
349 	},
350 	{
351 		.rate = I2C_MAX_FAST_MODE_FREQ,
352 		.fall_max = 300,
353 		.rise_max = 300,
354 		.hddat_min = 0,
355 		.vddat_max = 900,
356 		.sudat_min = 100,
357 		.l_min = 1300,
358 		.h_min = 600,
359 	},
360 	{
361 		.rate = I2C_MAX_FAST_MODE_PLUS_FREQ,
362 		.fall_max = 100,
363 		.rise_max = 120,
364 		.hddat_min = 0,
365 		.vddat_max = 450,
366 		.sudat_min = 50,
367 		.l_min = 500,
368 		.h_min = 260,
369 	},
370 };
371 
372 static const struct stm32f7_i2c_setup stm32f7_setup = {
373 	.rise_time = STM32F7_I2C_RISE_TIME_DEFAULT,
374 	.fall_time = STM32F7_I2C_FALL_TIME_DEFAULT,
375 	.dnf = STM32F7_I2C_DNF_DEFAULT,
376 	.analog_filter = STM32F7_I2C_ANALOG_FILTER_ENABLE,
377 };
378 
379 static const struct stm32f7_i2c_setup stm32mp15_setup = {
380 	.rise_time = STM32F7_I2C_RISE_TIME_DEFAULT,
381 	.fall_time = STM32F7_I2C_FALL_TIME_DEFAULT,
382 	.dnf = STM32F7_I2C_DNF_DEFAULT,
383 	.analog_filter = STM32F7_I2C_ANALOG_FILTER_ENABLE,
384 	.fmp_clr_offset = 0x40,
385 };
386 
387 static inline void stm32f7_i2c_set_bits(void __iomem *reg, u32 mask)
388 {
389 	writel_relaxed(readl_relaxed(reg) | mask, reg);
390 }
391 
392 static inline void stm32f7_i2c_clr_bits(void __iomem *reg, u32 mask)
393 {
394 	writel_relaxed(readl_relaxed(reg) & ~mask, reg);
395 }
396 
397 static void stm32f7_i2c_disable_irq(struct stm32f7_i2c_dev *i2c_dev, u32 mask)
398 {
399 	stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1, mask);
400 }
401 
402 static struct stm32f7_i2c_spec *stm32f7_get_specs(u32 rate)
403 {
404 	int i;
405 
406 	for (i = 0; i < ARRAY_SIZE(stm32f7_i2c_specs); i++)
407 		if (rate <= stm32f7_i2c_specs[i].rate)
408 			return &stm32f7_i2c_specs[i];
409 
410 	return ERR_PTR(-EINVAL);
411 }
412 
413 #define	RATE_MIN(rate)	((rate) * 8 / 10)
414 static int stm32f7_i2c_compute_timing(struct stm32f7_i2c_dev *i2c_dev,
415 				      struct stm32f7_i2c_setup *setup,
416 				      struct stm32f7_i2c_timings *output)
417 {
418 	struct stm32f7_i2c_spec *specs;
419 	u32 p_prev = STM32F7_PRESC_MAX;
420 	u32 i2cclk = DIV_ROUND_CLOSEST(NSEC_PER_SEC,
421 				       setup->clock_src);
422 	u32 i2cbus = DIV_ROUND_CLOSEST(NSEC_PER_SEC,
423 				       setup->speed_freq);
424 	u32 clk_error_prev = i2cbus;
425 	u32 tsync;
426 	u32 af_delay_min, af_delay_max;
427 	u32 dnf_delay;
428 	u32 clk_min, clk_max;
429 	int sdadel_min, sdadel_max;
430 	int scldel_min;
431 	struct stm32f7_i2c_timings *v, *_v, *s;
432 	struct list_head solutions;
433 	u16 p, l, a, h;
434 	int ret = 0;
435 
436 	specs = stm32f7_get_specs(setup->speed_freq);
437 	if (specs == ERR_PTR(-EINVAL)) {
438 		dev_err(i2c_dev->dev, "speed out of bound {%d}\n",
439 			setup->speed_freq);
440 		return -EINVAL;
441 	}
442 
443 	if ((setup->rise_time > specs->rise_max) ||
444 	    (setup->fall_time > specs->fall_max)) {
445 		dev_err(i2c_dev->dev,
446 			"timings out of bound Rise{%d>%d}/Fall{%d>%d}\n",
447 			setup->rise_time, specs->rise_max,
448 			setup->fall_time, specs->fall_max);
449 		return -EINVAL;
450 	}
451 
452 	if (setup->dnf > STM32F7_I2C_DNF_MAX) {
453 		dev_err(i2c_dev->dev,
454 			"DNF out of bound %d/%d\n",
455 			setup->dnf, STM32F7_I2C_DNF_MAX);
456 		return -EINVAL;
457 	}
458 
459 	/*  Analog and Digital Filters */
460 	af_delay_min =
461 		(setup->analog_filter ?
462 		 STM32F7_I2C_ANALOG_FILTER_DELAY_MIN : 0);
463 	af_delay_max =
464 		(setup->analog_filter ?
465 		 STM32F7_I2C_ANALOG_FILTER_DELAY_MAX : 0);
466 	dnf_delay = setup->dnf * i2cclk;
467 
468 	sdadel_min = specs->hddat_min + setup->fall_time -
469 		af_delay_min - (setup->dnf + 3) * i2cclk;
470 
471 	sdadel_max = specs->vddat_max - setup->rise_time -
472 		af_delay_max - (setup->dnf + 4) * i2cclk;
473 
474 	scldel_min = setup->rise_time + specs->sudat_min;
475 
476 	if (sdadel_min < 0)
477 		sdadel_min = 0;
478 	if (sdadel_max < 0)
479 		sdadel_max = 0;
480 
481 	dev_dbg(i2c_dev->dev, "SDADEL(min/max): %i/%i, SCLDEL(Min): %i\n",
482 		sdadel_min, sdadel_max, scldel_min);
483 
484 	INIT_LIST_HEAD(&solutions);
485 	/* Compute possible values for PRESC, SCLDEL and SDADEL */
486 	for (p = 0; p < STM32F7_PRESC_MAX; p++) {
487 		for (l = 0; l < STM32F7_SCLDEL_MAX; l++) {
488 			u32 scldel = (l + 1) * (p + 1) * i2cclk;
489 
490 			if (scldel < scldel_min)
491 				continue;
492 
493 			for (a = 0; a < STM32F7_SDADEL_MAX; a++) {
494 				u32 sdadel = (a * (p + 1) + 1) * i2cclk;
495 
496 				if (((sdadel >= sdadel_min) &&
497 				     (sdadel <= sdadel_max)) &&
498 				    (p != p_prev)) {
499 					v = kmalloc(sizeof(*v), GFP_KERNEL);
500 					if (!v) {
501 						ret = -ENOMEM;
502 						goto exit;
503 					}
504 
505 					v->presc = p;
506 					v->scldel = l;
507 					v->sdadel = a;
508 					p_prev = p;
509 
510 					list_add_tail(&v->node,
511 						      &solutions);
512 					break;
513 				}
514 			}
515 
516 			if (p_prev == p)
517 				break;
518 		}
519 	}
520 
521 	if (list_empty(&solutions)) {
522 		dev_err(i2c_dev->dev, "no Prescaler solution\n");
523 		ret = -EPERM;
524 		goto exit;
525 	}
526 
527 	tsync = af_delay_min + dnf_delay + (2 * i2cclk);
528 	s = NULL;
529 	clk_max = NSEC_PER_SEC / RATE_MIN(setup->speed_freq);
530 	clk_min = NSEC_PER_SEC / setup->speed_freq;
531 
532 	/*
533 	 * Among Prescaler possibilities discovered above figures out SCL Low
534 	 * and High Period. Provided:
535 	 * - SCL Low Period has to be higher than SCL Clock Low Period
536 	 *   defined by I2C Specification. I2C Clock has to be lower than
537 	 *   (SCL Low Period - Analog/Digital filters) / 4.
538 	 * - SCL High Period has to be lower than SCL Clock High Period
539 	 *   defined by I2C Specification
540 	 * - I2C Clock has to be lower than SCL High Period
541 	 */
542 	list_for_each_entry(v, &solutions, node) {
543 		u32 prescaler = (v->presc + 1) * i2cclk;
544 
545 		for (l = 0; l < STM32F7_SCLL_MAX; l++) {
546 			u32 tscl_l = (l + 1) * prescaler + tsync;
547 
548 			if ((tscl_l < specs->l_min) ||
549 			    (i2cclk >=
550 			     ((tscl_l - af_delay_min - dnf_delay) / 4))) {
551 				continue;
552 			}
553 
554 			for (h = 0; h < STM32F7_SCLH_MAX; h++) {
555 				u32 tscl_h = (h + 1) * prescaler + tsync;
556 				u32 tscl = tscl_l + tscl_h +
557 					setup->rise_time + setup->fall_time;
558 
559 				if ((tscl >= clk_min) && (tscl <= clk_max) &&
560 				    (tscl_h >= specs->h_min) &&
561 				    (i2cclk < tscl_h)) {
562 					int clk_error = tscl - i2cbus;
563 
564 					if (clk_error < 0)
565 						clk_error = -clk_error;
566 
567 					if (clk_error < clk_error_prev) {
568 						clk_error_prev = clk_error;
569 						v->scll = l;
570 						v->sclh = h;
571 						s = v;
572 					}
573 				}
574 			}
575 		}
576 	}
577 
578 	if (!s) {
579 		dev_err(i2c_dev->dev, "no solution at all\n");
580 		ret = -EPERM;
581 		goto exit;
582 	}
583 
584 	output->presc = s->presc;
585 	output->scldel = s->scldel;
586 	output->sdadel = s->sdadel;
587 	output->scll = s->scll;
588 	output->sclh = s->sclh;
589 
590 	dev_dbg(i2c_dev->dev,
591 		"Presc: %i, scldel: %i, sdadel: %i, scll: %i, sclh: %i\n",
592 		output->presc,
593 		output->scldel, output->sdadel,
594 		output->scll, output->sclh);
595 
596 exit:
597 	/* Release list and memory */
598 	list_for_each_entry_safe(v, _v, &solutions, node) {
599 		list_del(&v->node);
600 		kfree(v);
601 	}
602 
603 	return ret;
604 }
605 
606 static u32 stm32f7_get_lower_rate(u32 rate)
607 {
608 	int i = ARRAY_SIZE(stm32f7_i2c_specs);
609 
610 	while (--i)
611 		if (stm32f7_i2c_specs[i].rate < rate)
612 			break;
613 
614 	return stm32f7_i2c_specs[i].rate;
615 }
616 
617 static int stm32f7_i2c_setup_timing(struct stm32f7_i2c_dev *i2c_dev,
618 				    struct stm32f7_i2c_setup *setup)
619 {
620 	struct i2c_timings timings, *t = &timings;
621 	int ret = 0;
622 
623 	t->bus_freq_hz = I2C_MAX_STANDARD_MODE_FREQ;
624 	t->scl_rise_ns = i2c_dev->setup.rise_time;
625 	t->scl_fall_ns = i2c_dev->setup.fall_time;
626 
627 	i2c_parse_fw_timings(i2c_dev->dev, t, false);
628 
629 	if (t->bus_freq_hz > I2C_MAX_FAST_MODE_PLUS_FREQ) {
630 		dev_err(i2c_dev->dev, "Invalid bus speed (%i>%i)\n",
631 			t->bus_freq_hz, I2C_MAX_FAST_MODE_PLUS_FREQ);
632 		return -EINVAL;
633 	}
634 
635 	setup->speed_freq = t->bus_freq_hz;
636 	i2c_dev->setup.rise_time = t->scl_rise_ns;
637 	i2c_dev->setup.fall_time = t->scl_fall_ns;
638 	setup->clock_src = clk_get_rate(i2c_dev->clk);
639 
640 	if (!setup->clock_src) {
641 		dev_err(i2c_dev->dev, "clock rate is 0\n");
642 		return -EINVAL;
643 	}
644 
645 	do {
646 		ret = stm32f7_i2c_compute_timing(i2c_dev, setup,
647 						 &i2c_dev->timing);
648 		if (ret) {
649 			dev_err(i2c_dev->dev,
650 				"failed to compute I2C timings.\n");
651 			if (setup->speed_freq <= I2C_MAX_STANDARD_MODE_FREQ)
652 				break;
653 			setup->speed_freq =
654 				stm32f7_get_lower_rate(setup->speed_freq);
655 			dev_warn(i2c_dev->dev,
656 				 "downgrade I2C Speed Freq to (%i)\n",
657 				 setup->speed_freq);
658 		}
659 	} while (ret);
660 
661 	if (ret) {
662 		dev_err(i2c_dev->dev, "Impossible to compute I2C timings.\n");
663 		return ret;
664 	}
665 
666 	dev_dbg(i2c_dev->dev, "I2C Speed(%i), Clk Source(%i)\n",
667 		setup->speed_freq, setup->clock_src);
668 	dev_dbg(i2c_dev->dev, "I2C Rise(%i) and Fall(%i) Time\n",
669 		setup->rise_time, setup->fall_time);
670 	dev_dbg(i2c_dev->dev, "I2C Analog Filter(%s), DNF(%i)\n",
671 		(setup->analog_filter ? "On" : "Off"), setup->dnf);
672 
673 	i2c_dev->bus_rate = setup->speed_freq;
674 
675 	return 0;
676 }
677 
678 static void stm32f7_i2c_disable_dma_req(struct stm32f7_i2c_dev *i2c_dev)
679 {
680 	void __iomem *base = i2c_dev->base;
681 	u32 mask = STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN;
682 
683 	stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, mask);
684 }
685 
686 static void stm32f7_i2c_dma_callback(void *arg)
687 {
688 	struct stm32f7_i2c_dev *i2c_dev = (struct stm32f7_i2c_dev *)arg;
689 	struct stm32_i2c_dma *dma = i2c_dev->dma;
690 	struct device *dev = dma->chan_using->device->dev;
691 
692 	stm32f7_i2c_disable_dma_req(i2c_dev);
693 	dma_unmap_single(dev, dma->dma_buf, dma->dma_len, dma->dma_data_dir);
694 	complete(&dma->dma_complete);
695 }
696 
697 static void stm32f7_i2c_hw_config(struct stm32f7_i2c_dev *i2c_dev)
698 {
699 	struct stm32f7_i2c_timings *t = &i2c_dev->timing;
700 	u32 timing = 0;
701 
702 	/* Timing settings */
703 	timing |= STM32F7_I2C_TIMINGR_PRESC(t->presc);
704 	timing |= STM32F7_I2C_TIMINGR_SCLDEL(t->scldel);
705 	timing |= STM32F7_I2C_TIMINGR_SDADEL(t->sdadel);
706 	timing |= STM32F7_I2C_TIMINGR_SCLH(t->sclh);
707 	timing |= STM32F7_I2C_TIMINGR_SCLL(t->scll);
708 	writel_relaxed(timing, i2c_dev->base + STM32F7_I2C_TIMINGR);
709 
710 	/* Enable I2C */
711 	if (i2c_dev->setup.analog_filter)
712 		stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1,
713 				     STM32F7_I2C_CR1_ANFOFF);
714 	else
715 		stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,
716 				     STM32F7_I2C_CR1_ANFOFF);
717 	stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,
718 			     STM32F7_I2C_CR1_PE);
719 }
720 
721 static void stm32f7_i2c_write_tx_data(struct stm32f7_i2c_dev *i2c_dev)
722 {
723 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
724 	void __iomem *base = i2c_dev->base;
725 
726 	if (f7_msg->count) {
727 		writeb_relaxed(*f7_msg->buf++, base + STM32F7_I2C_TXDR);
728 		f7_msg->count--;
729 	}
730 }
731 
732 static void stm32f7_i2c_read_rx_data(struct stm32f7_i2c_dev *i2c_dev)
733 {
734 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
735 	void __iomem *base = i2c_dev->base;
736 
737 	if (f7_msg->count) {
738 		*f7_msg->buf++ = readb_relaxed(base + STM32F7_I2C_RXDR);
739 		f7_msg->count--;
740 	} else {
741 		/* Flush RX buffer has no data is expected */
742 		readb_relaxed(base + STM32F7_I2C_RXDR);
743 	}
744 }
745 
746 static void stm32f7_i2c_reload(struct stm32f7_i2c_dev *i2c_dev)
747 {
748 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
749 	u32 cr2;
750 
751 	if (i2c_dev->use_dma)
752 		f7_msg->count -= STM32F7_I2C_MAX_LEN;
753 
754 	cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
755 
756 	cr2 &= ~STM32F7_I2C_CR2_NBYTES_MASK;
757 	if (f7_msg->count > STM32F7_I2C_MAX_LEN) {
758 		cr2 |= STM32F7_I2C_CR2_NBYTES(STM32F7_I2C_MAX_LEN);
759 	} else {
760 		cr2 &= ~STM32F7_I2C_CR2_RELOAD;
761 		cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
762 	}
763 
764 	writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2);
765 }
766 
767 static void stm32f7_i2c_smbus_reload(struct stm32f7_i2c_dev *i2c_dev)
768 {
769 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
770 	u32 cr2;
771 	u8 *val;
772 
773 	/*
774 	 * For I2C_SMBUS_BLOCK_DATA && I2C_SMBUS_BLOCK_PROC_CALL, the first
775 	 * data received inform us how many data will follow.
776 	 */
777 	stm32f7_i2c_read_rx_data(i2c_dev);
778 
779 	/*
780 	 * Update NBYTES with the value read to continue the transfer
781 	 */
782 	val = f7_msg->buf - sizeof(u8);
783 	f7_msg->count = *val;
784 	cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
785 	cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK | STM32F7_I2C_CR2_RELOAD);
786 	cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
787 	writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2);
788 }
789 
790 static int stm32f7_i2c_release_bus(struct i2c_adapter *i2c_adap)
791 {
792 	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap);
793 
794 	dev_info(i2c_dev->dev, "Trying to recover bus\n");
795 
796 	stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1,
797 			     STM32F7_I2C_CR1_PE);
798 
799 	stm32f7_i2c_hw_config(i2c_dev);
800 
801 	return 0;
802 }
803 
804 static int stm32f7_i2c_wait_free_bus(struct stm32f7_i2c_dev *i2c_dev)
805 {
806 	u32 status;
807 	int ret;
808 
809 	ret = readl_relaxed_poll_timeout(i2c_dev->base + STM32F7_I2C_ISR,
810 					 status,
811 					 !(status & STM32F7_I2C_ISR_BUSY),
812 					 10, 1000);
813 	if (!ret)
814 		return 0;
815 
816 	dev_info(i2c_dev->dev, "bus busy\n");
817 
818 	ret = stm32f7_i2c_release_bus(&i2c_dev->adap);
819 	if (ret) {
820 		dev_err(i2c_dev->dev, "Failed to recover the bus (%d)\n", ret);
821 		return ret;
822 	}
823 
824 	return -EBUSY;
825 }
826 
827 static void stm32f7_i2c_xfer_msg(struct stm32f7_i2c_dev *i2c_dev,
828 				 struct i2c_msg *msg)
829 {
830 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
831 	void __iomem *base = i2c_dev->base;
832 	u32 cr1, cr2;
833 	int ret;
834 
835 	f7_msg->addr = msg->addr;
836 	f7_msg->buf = msg->buf;
837 	f7_msg->count = msg->len;
838 	f7_msg->result = 0;
839 	f7_msg->stop = (i2c_dev->msg_id >= i2c_dev->msg_num - 1);
840 
841 	reinit_completion(&i2c_dev->complete);
842 
843 	cr1 = readl_relaxed(base + STM32F7_I2C_CR1);
844 	cr2 = readl_relaxed(base + STM32F7_I2C_CR2);
845 
846 	/* Set transfer direction */
847 	cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
848 	if (msg->flags & I2C_M_RD)
849 		cr2 |= STM32F7_I2C_CR2_RD_WRN;
850 
851 	/* Set slave address */
852 	cr2 &= ~(STM32F7_I2C_CR2_HEAD10R | STM32F7_I2C_CR2_ADD10);
853 	if (msg->flags & I2C_M_TEN) {
854 		cr2 &= ~STM32F7_I2C_CR2_SADD10_MASK;
855 		cr2 |= STM32F7_I2C_CR2_SADD10(f7_msg->addr);
856 		cr2 |= STM32F7_I2C_CR2_ADD10;
857 	} else {
858 		cr2 &= ~STM32F7_I2C_CR2_SADD7_MASK;
859 		cr2 |= STM32F7_I2C_CR2_SADD7(f7_msg->addr);
860 	}
861 
862 	/* Set nb bytes to transfer and reload if needed */
863 	cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK | STM32F7_I2C_CR2_RELOAD);
864 	if (f7_msg->count > STM32F7_I2C_MAX_LEN) {
865 		cr2 |= STM32F7_I2C_CR2_NBYTES(STM32F7_I2C_MAX_LEN);
866 		cr2 |= STM32F7_I2C_CR2_RELOAD;
867 	} else {
868 		cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
869 	}
870 
871 	/* Enable NACK, STOP, error and transfer complete interrupts */
872 	cr1 |= STM32F7_I2C_CR1_ERRIE | STM32F7_I2C_CR1_TCIE |
873 		STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE;
874 
875 	/* Clear DMA req and TX/RX interrupt */
876 	cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE |
877 			STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN);
878 
879 	/* Configure DMA or enable RX/TX interrupt */
880 	i2c_dev->use_dma = false;
881 	if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN) {
882 		ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma,
883 					      msg->flags & I2C_M_RD,
884 					      f7_msg->count, f7_msg->buf,
885 					      stm32f7_i2c_dma_callback,
886 					      i2c_dev);
887 		if (!ret)
888 			i2c_dev->use_dma = true;
889 		else
890 			dev_warn(i2c_dev->dev, "can't use DMA\n");
891 	}
892 
893 	if (!i2c_dev->use_dma) {
894 		if (msg->flags & I2C_M_RD)
895 			cr1 |= STM32F7_I2C_CR1_RXIE;
896 		else
897 			cr1 |= STM32F7_I2C_CR1_TXIE;
898 	} else {
899 		if (msg->flags & I2C_M_RD)
900 			cr1 |= STM32F7_I2C_CR1_RXDMAEN;
901 		else
902 			cr1 |= STM32F7_I2C_CR1_TXDMAEN;
903 	}
904 
905 	/* Configure Start/Repeated Start */
906 	cr2 |= STM32F7_I2C_CR2_START;
907 
908 	i2c_dev->master_mode = true;
909 
910 	/* Write configurations registers */
911 	writel_relaxed(cr1, base + STM32F7_I2C_CR1);
912 	writel_relaxed(cr2, base + STM32F7_I2C_CR2);
913 }
914 
915 static int stm32f7_i2c_smbus_xfer_msg(struct stm32f7_i2c_dev *i2c_dev,
916 				      unsigned short flags, u8 command,
917 				      union i2c_smbus_data *data)
918 {
919 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
920 	struct device *dev = i2c_dev->dev;
921 	void __iomem *base = i2c_dev->base;
922 	u32 cr1, cr2;
923 	int i, ret;
924 
925 	f7_msg->result = 0;
926 	reinit_completion(&i2c_dev->complete);
927 
928 	cr2 = readl_relaxed(base + STM32F7_I2C_CR2);
929 	cr1 = readl_relaxed(base + STM32F7_I2C_CR1);
930 
931 	/* Set transfer direction */
932 	cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
933 	if (f7_msg->read_write)
934 		cr2 |= STM32F7_I2C_CR2_RD_WRN;
935 
936 	/* Set slave address */
937 	cr2 &= ~(STM32F7_I2C_CR2_ADD10 | STM32F7_I2C_CR2_SADD7_MASK);
938 	cr2 |= STM32F7_I2C_CR2_SADD7(f7_msg->addr);
939 
940 	f7_msg->smbus_buf[0] = command;
941 	switch (f7_msg->size) {
942 	case I2C_SMBUS_QUICK:
943 		f7_msg->stop = true;
944 		f7_msg->count = 0;
945 		break;
946 	case I2C_SMBUS_BYTE:
947 		f7_msg->stop = true;
948 		f7_msg->count = 1;
949 		break;
950 	case I2C_SMBUS_BYTE_DATA:
951 		if (f7_msg->read_write) {
952 			f7_msg->stop = false;
953 			f7_msg->count = 1;
954 			cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
955 		} else {
956 			f7_msg->stop = true;
957 			f7_msg->count = 2;
958 			f7_msg->smbus_buf[1] = data->byte;
959 		}
960 		break;
961 	case I2C_SMBUS_WORD_DATA:
962 		if (f7_msg->read_write) {
963 			f7_msg->stop = false;
964 			f7_msg->count = 1;
965 			cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
966 		} else {
967 			f7_msg->stop = true;
968 			f7_msg->count = 3;
969 			f7_msg->smbus_buf[1] = data->word & 0xff;
970 			f7_msg->smbus_buf[2] = data->word >> 8;
971 		}
972 		break;
973 	case I2C_SMBUS_BLOCK_DATA:
974 		if (f7_msg->read_write) {
975 			f7_msg->stop = false;
976 			f7_msg->count = 1;
977 			cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
978 		} else {
979 			f7_msg->stop = true;
980 			if (data->block[0] > I2C_SMBUS_BLOCK_MAX ||
981 			    !data->block[0]) {
982 				dev_err(dev, "Invalid block write size %d\n",
983 					data->block[0]);
984 				return -EINVAL;
985 			}
986 			f7_msg->count = data->block[0] + 2;
987 			for (i = 1; i < f7_msg->count; i++)
988 				f7_msg->smbus_buf[i] = data->block[i - 1];
989 		}
990 		break;
991 	case I2C_SMBUS_PROC_CALL:
992 		f7_msg->stop = false;
993 		f7_msg->count = 3;
994 		f7_msg->smbus_buf[1] = data->word & 0xff;
995 		f7_msg->smbus_buf[2] = data->word >> 8;
996 		cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
997 		f7_msg->read_write = I2C_SMBUS_READ;
998 		break;
999 	case I2C_SMBUS_BLOCK_PROC_CALL:
1000 		f7_msg->stop = false;
1001 		if (data->block[0] > I2C_SMBUS_BLOCK_MAX - 1) {
1002 			dev_err(dev, "Invalid block write size %d\n",
1003 				data->block[0]);
1004 			return -EINVAL;
1005 		}
1006 		f7_msg->count = data->block[0] + 2;
1007 		for (i = 1; i < f7_msg->count; i++)
1008 			f7_msg->smbus_buf[i] = data->block[i - 1];
1009 		cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
1010 		f7_msg->read_write = I2C_SMBUS_READ;
1011 		break;
1012 	case I2C_SMBUS_I2C_BLOCK_DATA:
1013 		/* Rely on emulated i2c transfer (through master_xfer) */
1014 		return -EOPNOTSUPP;
1015 	default:
1016 		dev_err(dev, "Unsupported smbus protocol %d\n", f7_msg->size);
1017 		return -EOPNOTSUPP;
1018 	}
1019 
1020 	f7_msg->buf = f7_msg->smbus_buf;
1021 
1022 	/* Configure PEC */
1023 	if ((flags & I2C_CLIENT_PEC) && f7_msg->size != I2C_SMBUS_QUICK) {
1024 		cr1 |= STM32F7_I2C_CR1_PECEN;
1025 		cr2 |= STM32F7_I2C_CR2_PECBYTE;
1026 		if (!f7_msg->read_write)
1027 			f7_msg->count++;
1028 	} else {
1029 		cr1 &= ~STM32F7_I2C_CR1_PECEN;
1030 		cr2 &= ~STM32F7_I2C_CR2_PECBYTE;
1031 	}
1032 
1033 	/* Set number of bytes to be transferred */
1034 	cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK | STM32F7_I2C_CR2_RELOAD);
1035 	cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
1036 
1037 	/* Enable NACK, STOP, error and transfer complete interrupts */
1038 	cr1 |= STM32F7_I2C_CR1_ERRIE | STM32F7_I2C_CR1_TCIE |
1039 		STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE;
1040 
1041 	/* Clear DMA req and TX/RX interrupt */
1042 	cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE |
1043 			STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN);
1044 
1045 	/* Configure DMA or enable RX/TX interrupt */
1046 	i2c_dev->use_dma = false;
1047 	if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN) {
1048 		ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma,
1049 					      cr2 & STM32F7_I2C_CR2_RD_WRN,
1050 					      f7_msg->count, f7_msg->buf,
1051 					      stm32f7_i2c_dma_callback,
1052 					      i2c_dev);
1053 		if (!ret)
1054 			i2c_dev->use_dma = true;
1055 		else
1056 			dev_warn(i2c_dev->dev, "can't use DMA\n");
1057 	}
1058 
1059 	if (!i2c_dev->use_dma) {
1060 		if (cr2 & STM32F7_I2C_CR2_RD_WRN)
1061 			cr1 |= STM32F7_I2C_CR1_RXIE;
1062 		else
1063 			cr1 |= STM32F7_I2C_CR1_TXIE;
1064 	} else {
1065 		if (cr2 & STM32F7_I2C_CR2_RD_WRN)
1066 			cr1 |= STM32F7_I2C_CR1_RXDMAEN;
1067 		else
1068 			cr1 |= STM32F7_I2C_CR1_TXDMAEN;
1069 	}
1070 
1071 	/* Set Start bit */
1072 	cr2 |= STM32F7_I2C_CR2_START;
1073 
1074 	i2c_dev->master_mode = true;
1075 
1076 	/* Write configurations registers */
1077 	writel_relaxed(cr1, base + STM32F7_I2C_CR1);
1078 	writel_relaxed(cr2, base + STM32F7_I2C_CR2);
1079 
1080 	return 0;
1081 }
1082 
1083 static void stm32f7_i2c_smbus_rep_start(struct stm32f7_i2c_dev *i2c_dev)
1084 {
1085 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1086 	void __iomem *base = i2c_dev->base;
1087 	u32 cr1, cr2;
1088 	int ret;
1089 
1090 	cr2 = readl_relaxed(base + STM32F7_I2C_CR2);
1091 	cr1 = readl_relaxed(base + STM32F7_I2C_CR1);
1092 
1093 	/* Set transfer direction */
1094 	cr2 |= STM32F7_I2C_CR2_RD_WRN;
1095 
1096 	switch (f7_msg->size) {
1097 	case I2C_SMBUS_BYTE_DATA:
1098 		f7_msg->count = 1;
1099 		break;
1100 	case I2C_SMBUS_WORD_DATA:
1101 	case I2C_SMBUS_PROC_CALL:
1102 		f7_msg->count = 2;
1103 		break;
1104 	case I2C_SMBUS_BLOCK_DATA:
1105 	case I2C_SMBUS_BLOCK_PROC_CALL:
1106 		f7_msg->count = 1;
1107 		cr2 |= STM32F7_I2C_CR2_RELOAD;
1108 		break;
1109 	}
1110 
1111 	f7_msg->buf = f7_msg->smbus_buf;
1112 	f7_msg->stop = true;
1113 
1114 	/* Add one byte for PEC if needed */
1115 	if (cr1 & STM32F7_I2C_CR1_PECEN)
1116 		f7_msg->count++;
1117 
1118 	/* Set number of bytes to be transferred */
1119 	cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK);
1120 	cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
1121 
1122 	/*
1123 	 * Configure RX/TX interrupt:
1124 	 */
1125 	cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE);
1126 	cr1 |= STM32F7_I2C_CR1_RXIE;
1127 
1128 	/*
1129 	 * Configure DMA or enable RX/TX interrupt:
1130 	 * For I2C_SMBUS_BLOCK_DATA and I2C_SMBUS_BLOCK_PROC_CALL we don't use
1131 	 * dma as we don't know in advance how many data will be received
1132 	 */
1133 	cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE |
1134 		 STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN);
1135 
1136 	i2c_dev->use_dma = false;
1137 	if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN &&
1138 	    f7_msg->size != I2C_SMBUS_BLOCK_DATA &&
1139 	    f7_msg->size != I2C_SMBUS_BLOCK_PROC_CALL) {
1140 		ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma,
1141 					      cr2 & STM32F7_I2C_CR2_RD_WRN,
1142 					      f7_msg->count, f7_msg->buf,
1143 					      stm32f7_i2c_dma_callback,
1144 					      i2c_dev);
1145 
1146 		if (!ret)
1147 			i2c_dev->use_dma = true;
1148 		else
1149 			dev_warn(i2c_dev->dev, "can't use DMA\n");
1150 	}
1151 
1152 	if (!i2c_dev->use_dma)
1153 		cr1 |= STM32F7_I2C_CR1_RXIE;
1154 	else
1155 		cr1 |= STM32F7_I2C_CR1_RXDMAEN;
1156 
1157 	/* Configure Repeated Start */
1158 	cr2 |= STM32F7_I2C_CR2_START;
1159 
1160 	/* Write configurations registers */
1161 	writel_relaxed(cr1, base + STM32F7_I2C_CR1);
1162 	writel_relaxed(cr2, base + STM32F7_I2C_CR2);
1163 }
1164 
1165 static int stm32f7_i2c_smbus_check_pec(struct stm32f7_i2c_dev *i2c_dev)
1166 {
1167 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1168 	u8 count, internal_pec, received_pec;
1169 
1170 	internal_pec = readl_relaxed(i2c_dev->base + STM32F7_I2C_PECR);
1171 
1172 	switch (f7_msg->size) {
1173 	case I2C_SMBUS_BYTE:
1174 	case I2C_SMBUS_BYTE_DATA:
1175 		received_pec = f7_msg->smbus_buf[1];
1176 		break;
1177 	case I2C_SMBUS_WORD_DATA:
1178 	case I2C_SMBUS_PROC_CALL:
1179 		received_pec = f7_msg->smbus_buf[2];
1180 		break;
1181 	case I2C_SMBUS_BLOCK_DATA:
1182 	case I2C_SMBUS_BLOCK_PROC_CALL:
1183 		count = f7_msg->smbus_buf[0];
1184 		received_pec = f7_msg->smbus_buf[count];
1185 		break;
1186 	default:
1187 		dev_err(i2c_dev->dev, "Unsupported smbus protocol for PEC\n");
1188 		return -EINVAL;
1189 	}
1190 
1191 	if (internal_pec != received_pec) {
1192 		dev_err(i2c_dev->dev, "Bad PEC 0x%02x vs. 0x%02x\n",
1193 			internal_pec, received_pec);
1194 		return -EBADMSG;
1195 	}
1196 
1197 	return 0;
1198 }
1199 
1200 static bool stm32f7_i2c_is_addr_match(struct i2c_client *slave, u32 addcode)
1201 {
1202 	u32 addr;
1203 
1204 	if (!slave)
1205 		return false;
1206 
1207 	if (slave->flags & I2C_CLIENT_TEN) {
1208 		/*
1209 		 * For 10-bit addr, addcode = 11110XY with
1210 		 * X = Bit 9 of slave address
1211 		 * Y = Bit 8 of slave address
1212 		 */
1213 		addr = slave->addr >> 8;
1214 		addr |= 0x78;
1215 		if (addr == addcode)
1216 			return true;
1217 	} else {
1218 		addr = slave->addr & 0x7f;
1219 		if (addr == addcode)
1220 			return true;
1221 	}
1222 
1223 	return false;
1224 }
1225 
1226 static void stm32f7_i2c_slave_start(struct stm32f7_i2c_dev *i2c_dev)
1227 {
1228 	struct i2c_client *slave = i2c_dev->slave_running;
1229 	void __iomem *base = i2c_dev->base;
1230 	u32 mask;
1231 	u8 value = 0;
1232 
1233 	if (i2c_dev->slave_dir) {
1234 		/* Notify i2c slave that new read transfer is starting */
1235 		i2c_slave_event(slave, I2C_SLAVE_READ_REQUESTED, &value);
1236 
1237 		/*
1238 		 * Disable slave TX config in case of I2C combined message
1239 		 * (I2C Write followed by I2C Read)
1240 		 */
1241 		mask = STM32F7_I2C_CR2_RELOAD;
1242 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR2, mask);
1243 		mask = STM32F7_I2C_CR1_SBC | STM32F7_I2C_CR1_RXIE |
1244 		       STM32F7_I2C_CR1_TCIE;
1245 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, mask);
1246 
1247 		/* Enable TX empty, STOP, NACK interrupts */
1248 		mask =  STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE |
1249 			STM32F7_I2C_CR1_TXIE;
1250 		stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
1251 
1252 		/* Write 1st data byte */
1253 		writel_relaxed(value, base + STM32F7_I2C_TXDR);
1254 	} else {
1255 		/* Notify i2c slave that new write transfer is starting */
1256 		i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value);
1257 
1258 		/* Set reload mode to be able to ACK/NACK each received byte */
1259 		mask = STM32F7_I2C_CR2_RELOAD;
1260 		stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask);
1261 
1262 		/*
1263 		 * Set STOP, NACK, RX empty and transfer complete interrupts.*
1264 		 * Set Slave Byte Control to be able to ACK/NACK each data
1265 		 * byte received
1266 		 */
1267 		mask =  STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE |
1268 			STM32F7_I2C_CR1_SBC | STM32F7_I2C_CR1_RXIE |
1269 			STM32F7_I2C_CR1_TCIE;
1270 		stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
1271 	}
1272 }
1273 
1274 static void stm32f7_i2c_slave_addr(struct stm32f7_i2c_dev *i2c_dev)
1275 {
1276 	void __iomem *base = i2c_dev->base;
1277 	u32 isr, addcode, dir, mask;
1278 	int i;
1279 
1280 	isr = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
1281 	addcode = STM32F7_I2C_ISR_ADDCODE_GET(isr);
1282 	dir = isr & STM32F7_I2C_ISR_DIR;
1283 
1284 	for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) {
1285 		if (stm32f7_i2c_is_addr_match(i2c_dev->slave[i], addcode)) {
1286 			i2c_dev->slave_running = i2c_dev->slave[i];
1287 			i2c_dev->slave_dir = dir;
1288 
1289 			/* Start I2C slave processing */
1290 			stm32f7_i2c_slave_start(i2c_dev);
1291 
1292 			/* Clear ADDR flag */
1293 			mask = STM32F7_I2C_ICR_ADDRCF;
1294 			writel_relaxed(mask, base + STM32F7_I2C_ICR);
1295 			break;
1296 		}
1297 	}
1298 }
1299 
1300 static int stm32f7_i2c_get_slave_id(struct stm32f7_i2c_dev *i2c_dev,
1301 				    struct i2c_client *slave, int *id)
1302 {
1303 	int i;
1304 
1305 	for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) {
1306 		if (i2c_dev->slave[i] == slave) {
1307 			*id = i;
1308 			return 0;
1309 		}
1310 	}
1311 
1312 	dev_err(i2c_dev->dev, "Slave 0x%x not registered\n", slave->addr);
1313 
1314 	return -ENODEV;
1315 }
1316 
1317 static int stm32f7_i2c_get_free_slave_id(struct stm32f7_i2c_dev *i2c_dev,
1318 					 struct i2c_client *slave, int *id)
1319 {
1320 	struct device *dev = i2c_dev->dev;
1321 	int i;
1322 
1323 	/*
1324 	 * slave[0] supports 7-bit and 10-bit slave address
1325 	 * slave[1] supports 7-bit slave address only
1326 	 */
1327 	for (i = STM32F7_I2C_MAX_SLAVE - 1; i >= 0; i--) {
1328 		if (i == 1 && (slave->flags & I2C_CLIENT_TEN))
1329 			continue;
1330 		if (!i2c_dev->slave[i]) {
1331 			*id = i;
1332 			return 0;
1333 		}
1334 	}
1335 
1336 	dev_err(dev, "Slave 0x%x could not be registered\n", slave->addr);
1337 
1338 	return -EINVAL;
1339 }
1340 
1341 static bool stm32f7_i2c_is_slave_registered(struct stm32f7_i2c_dev *i2c_dev)
1342 {
1343 	int i;
1344 
1345 	for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) {
1346 		if (i2c_dev->slave[i])
1347 			return true;
1348 	}
1349 
1350 	return false;
1351 }
1352 
1353 static bool stm32f7_i2c_is_slave_busy(struct stm32f7_i2c_dev *i2c_dev)
1354 {
1355 	int i, busy;
1356 
1357 	busy = 0;
1358 	for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) {
1359 		if (i2c_dev->slave[i])
1360 			busy++;
1361 	}
1362 
1363 	return i == busy;
1364 }
1365 
1366 static irqreturn_t stm32f7_i2c_slave_isr_event(struct stm32f7_i2c_dev *i2c_dev)
1367 {
1368 	void __iomem *base = i2c_dev->base;
1369 	u32 cr2, status, mask;
1370 	u8 val;
1371 	int ret;
1372 
1373 	status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
1374 
1375 	/* Slave transmitter mode */
1376 	if (status & STM32F7_I2C_ISR_TXIS) {
1377 		i2c_slave_event(i2c_dev->slave_running,
1378 				I2C_SLAVE_READ_PROCESSED,
1379 				&val);
1380 
1381 		/* Write data byte */
1382 		writel_relaxed(val, base + STM32F7_I2C_TXDR);
1383 	}
1384 
1385 	/* Transfer Complete Reload for Slave receiver mode */
1386 	if (status & STM32F7_I2C_ISR_TCR || status & STM32F7_I2C_ISR_RXNE) {
1387 		/*
1388 		 * Read data byte then set NBYTES to receive next byte or NACK
1389 		 * the current received byte
1390 		 */
1391 		val = readb_relaxed(i2c_dev->base + STM32F7_I2C_RXDR);
1392 		ret = i2c_slave_event(i2c_dev->slave_running,
1393 				      I2C_SLAVE_WRITE_RECEIVED,
1394 				      &val);
1395 		if (!ret) {
1396 			cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
1397 			cr2 |= STM32F7_I2C_CR2_NBYTES(1);
1398 			writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2);
1399 		} else {
1400 			mask = STM32F7_I2C_CR2_NACK;
1401 			stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask);
1402 		}
1403 	}
1404 
1405 	/* NACK received */
1406 	if (status & STM32F7_I2C_ISR_NACKF) {
1407 		dev_dbg(i2c_dev->dev, "<%s>: Receive NACK\n", __func__);
1408 		writel_relaxed(STM32F7_I2C_ICR_NACKCF, base + STM32F7_I2C_ICR);
1409 	}
1410 
1411 	/* STOP received */
1412 	if (status & STM32F7_I2C_ISR_STOPF) {
1413 		/* Disable interrupts */
1414 		stm32f7_i2c_disable_irq(i2c_dev, STM32F7_I2C_XFER_IRQ_MASK);
1415 
1416 		if (i2c_dev->slave_dir) {
1417 			/*
1418 			 * Flush TX buffer in order to not used the byte in
1419 			 * TXDR for the next transfer
1420 			 */
1421 			mask = STM32F7_I2C_ISR_TXE;
1422 			stm32f7_i2c_set_bits(base + STM32F7_I2C_ISR, mask);
1423 		}
1424 
1425 		/* Clear STOP flag */
1426 		writel_relaxed(STM32F7_I2C_ICR_STOPCF, base + STM32F7_I2C_ICR);
1427 
1428 		/* Notify i2c slave that a STOP flag has been detected */
1429 		i2c_slave_event(i2c_dev->slave_running, I2C_SLAVE_STOP, &val);
1430 
1431 		i2c_dev->slave_running = NULL;
1432 	}
1433 
1434 	/* Address match received */
1435 	if (status & STM32F7_I2C_ISR_ADDR)
1436 		stm32f7_i2c_slave_addr(i2c_dev);
1437 
1438 	return IRQ_HANDLED;
1439 }
1440 
1441 static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data)
1442 {
1443 	struct stm32f7_i2c_dev *i2c_dev = data;
1444 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1445 	void __iomem *base = i2c_dev->base;
1446 	u32 status, mask;
1447 	int ret = IRQ_HANDLED;
1448 
1449 	/* Check if the interrupt if for a slave device */
1450 	if (!i2c_dev->master_mode) {
1451 		ret = stm32f7_i2c_slave_isr_event(i2c_dev);
1452 		return ret;
1453 	}
1454 
1455 	status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
1456 
1457 	/* Tx empty */
1458 	if (status & STM32F7_I2C_ISR_TXIS)
1459 		stm32f7_i2c_write_tx_data(i2c_dev);
1460 
1461 	/* RX not empty */
1462 	if (status & STM32F7_I2C_ISR_RXNE)
1463 		stm32f7_i2c_read_rx_data(i2c_dev);
1464 
1465 	/* NACK received */
1466 	if (status & STM32F7_I2C_ISR_NACKF) {
1467 		dev_dbg(i2c_dev->dev, "<%s>: Receive NACK (addr %x)\n",
1468 			__func__, f7_msg->addr);
1469 		writel_relaxed(STM32F7_I2C_ICR_NACKCF, base + STM32F7_I2C_ICR);
1470 		f7_msg->result = -ENXIO;
1471 	}
1472 
1473 	/* STOP detection flag */
1474 	if (status & STM32F7_I2C_ISR_STOPF) {
1475 		/* Disable interrupts */
1476 		if (stm32f7_i2c_is_slave_registered(i2c_dev))
1477 			mask = STM32F7_I2C_XFER_IRQ_MASK;
1478 		else
1479 			mask = STM32F7_I2C_ALL_IRQ_MASK;
1480 		stm32f7_i2c_disable_irq(i2c_dev, mask);
1481 
1482 		/* Clear STOP flag */
1483 		writel_relaxed(STM32F7_I2C_ICR_STOPCF, base + STM32F7_I2C_ICR);
1484 
1485 		if (i2c_dev->use_dma) {
1486 			ret = IRQ_WAKE_THREAD;
1487 		} else {
1488 			i2c_dev->master_mode = false;
1489 			complete(&i2c_dev->complete);
1490 		}
1491 	}
1492 
1493 	/* Transfer complete */
1494 	if (status & STM32F7_I2C_ISR_TC) {
1495 		if (f7_msg->stop) {
1496 			mask = STM32F7_I2C_CR2_STOP;
1497 			stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask);
1498 		} else if (i2c_dev->use_dma) {
1499 			ret = IRQ_WAKE_THREAD;
1500 		} else if (f7_msg->smbus) {
1501 			stm32f7_i2c_smbus_rep_start(i2c_dev);
1502 		} else {
1503 			i2c_dev->msg_id++;
1504 			i2c_dev->msg++;
1505 			stm32f7_i2c_xfer_msg(i2c_dev, i2c_dev->msg);
1506 		}
1507 	}
1508 
1509 	if (status & STM32F7_I2C_ISR_TCR) {
1510 		if (f7_msg->smbus)
1511 			stm32f7_i2c_smbus_reload(i2c_dev);
1512 		else
1513 			stm32f7_i2c_reload(i2c_dev);
1514 	}
1515 
1516 	return ret;
1517 }
1518 
1519 static irqreturn_t stm32f7_i2c_isr_event_thread(int irq, void *data)
1520 {
1521 	struct stm32f7_i2c_dev *i2c_dev = data;
1522 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1523 	struct stm32_i2c_dma *dma = i2c_dev->dma;
1524 	u32 status;
1525 	int ret;
1526 
1527 	/*
1528 	 * Wait for dma transfer completion before sending next message or
1529 	 * notity the end of xfer to the client
1530 	 */
1531 	ret = wait_for_completion_timeout(&i2c_dev->dma->dma_complete, HZ);
1532 	if (!ret) {
1533 		dev_dbg(i2c_dev->dev, "<%s>: Timed out\n", __func__);
1534 		stm32f7_i2c_disable_dma_req(i2c_dev);
1535 		dmaengine_terminate_all(dma->chan_using);
1536 		f7_msg->result = -ETIMEDOUT;
1537 	}
1538 
1539 	status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
1540 
1541 	if (status & STM32F7_I2C_ISR_TC) {
1542 		if (f7_msg->smbus) {
1543 			stm32f7_i2c_smbus_rep_start(i2c_dev);
1544 		} else {
1545 			i2c_dev->msg_id++;
1546 			i2c_dev->msg++;
1547 			stm32f7_i2c_xfer_msg(i2c_dev, i2c_dev->msg);
1548 		}
1549 	} else {
1550 		i2c_dev->master_mode = false;
1551 		complete(&i2c_dev->complete);
1552 	}
1553 
1554 	return IRQ_HANDLED;
1555 }
1556 
1557 static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data)
1558 {
1559 	struct stm32f7_i2c_dev *i2c_dev = data;
1560 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1561 	void __iomem *base = i2c_dev->base;
1562 	struct device *dev = i2c_dev->dev;
1563 	struct stm32_i2c_dma *dma = i2c_dev->dma;
1564 	u32 status;
1565 
1566 	status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
1567 
1568 	/* Bus error */
1569 	if (status & STM32F7_I2C_ISR_BERR) {
1570 		dev_err(dev, "<%s>: Bus error\n", __func__);
1571 		writel_relaxed(STM32F7_I2C_ICR_BERRCF, base + STM32F7_I2C_ICR);
1572 		stm32f7_i2c_release_bus(&i2c_dev->adap);
1573 		f7_msg->result = -EIO;
1574 	}
1575 
1576 	/* Arbitration loss */
1577 	if (status & STM32F7_I2C_ISR_ARLO) {
1578 		dev_dbg(dev, "<%s>: Arbitration loss\n", __func__);
1579 		writel_relaxed(STM32F7_I2C_ICR_ARLOCF, base + STM32F7_I2C_ICR);
1580 		f7_msg->result = -EAGAIN;
1581 	}
1582 
1583 	if (status & STM32F7_I2C_ISR_PECERR) {
1584 		dev_err(dev, "<%s>: PEC error in reception\n", __func__);
1585 		writel_relaxed(STM32F7_I2C_ICR_PECCF, base + STM32F7_I2C_ICR);
1586 		f7_msg->result = -EINVAL;
1587 	}
1588 
1589 	if (!i2c_dev->slave_running) {
1590 		u32 mask;
1591 		/* Disable interrupts */
1592 		if (stm32f7_i2c_is_slave_registered(i2c_dev))
1593 			mask = STM32F7_I2C_XFER_IRQ_MASK;
1594 		else
1595 			mask = STM32F7_I2C_ALL_IRQ_MASK;
1596 		stm32f7_i2c_disable_irq(i2c_dev, mask);
1597 	}
1598 
1599 	/* Disable dma */
1600 	if (i2c_dev->use_dma) {
1601 		stm32f7_i2c_disable_dma_req(i2c_dev);
1602 		dmaengine_terminate_all(dma->chan_using);
1603 	}
1604 
1605 	i2c_dev->master_mode = false;
1606 	complete(&i2c_dev->complete);
1607 
1608 	return IRQ_HANDLED;
1609 }
1610 
1611 static int stm32f7_i2c_xfer(struct i2c_adapter *i2c_adap,
1612 			    struct i2c_msg msgs[], int num)
1613 {
1614 	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap);
1615 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1616 	struct stm32_i2c_dma *dma = i2c_dev->dma;
1617 	unsigned long time_left;
1618 	int ret;
1619 
1620 	i2c_dev->msg = msgs;
1621 	i2c_dev->msg_num = num;
1622 	i2c_dev->msg_id = 0;
1623 	f7_msg->smbus = false;
1624 
1625 	ret = pm_runtime_get_sync(i2c_dev->dev);
1626 	if (ret < 0)
1627 		return ret;
1628 
1629 	ret = stm32f7_i2c_wait_free_bus(i2c_dev);
1630 	if (ret)
1631 		goto pm_free;
1632 
1633 	stm32f7_i2c_xfer_msg(i2c_dev, msgs);
1634 
1635 	time_left = wait_for_completion_timeout(&i2c_dev->complete,
1636 						i2c_dev->adap.timeout);
1637 	ret = f7_msg->result;
1638 
1639 	if (!time_left) {
1640 		dev_dbg(i2c_dev->dev, "Access to slave 0x%x timed out\n",
1641 			i2c_dev->msg->addr);
1642 		if (i2c_dev->use_dma)
1643 			dmaengine_terminate_all(dma->chan_using);
1644 		ret = -ETIMEDOUT;
1645 	}
1646 
1647 pm_free:
1648 	pm_runtime_mark_last_busy(i2c_dev->dev);
1649 	pm_runtime_put_autosuspend(i2c_dev->dev);
1650 
1651 	return (ret < 0) ? ret : num;
1652 }
1653 
1654 static int stm32f7_i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
1655 				  unsigned short flags, char read_write,
1656 				  u8 command, int size,
1657 				  union i2c_smbus_data *data)
1658 {
1659 	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(adapter);
1660 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1661 	struct stm32_i2c_dma *dma = i2c_dev->dma;
1662 	struct device *dev = i2c_dev->dev;
1663 	unsigned long timeout;
1664 	int i, ret;
1665 
1666 	f7_msg->addr = addr;
1667 	f7_msg->size = size;
1668 	f7_msg->read_write = read_write;
1669 	f7_msg->smbus = true;
1670 
1671 	ret = pm_runtime_get_sync(dev);
1672 	if (ret < 0)
1673 		return ret;
1674 
1675 	ret = stm32f7_i2c_wait_free_bus(i2c_dev);
1676 	if (ret)
1677 		goto pm_free;
1678 
1679 	ret = stm32f7_i2c_smbus_xfer_msg(i2c_dev, flags, command, data);
1680 	if (ret)
1681 		goto pm_free;
1682 
1683 	timeout = wait_for_completion_timeout(&i2c_dev->complete,
1684 					      i2c_dev->adap.timeout);
1685 	ret = f7_msg->result;
1686 	if (ret)
1687 		goto pm_free;
1688 
1689 	if (!timeout) {
1690 		dev_dbg(dev, "Access to slave 0x%x timed out\n", f7_msg->addr);
1691 		if (i2c_dev->use_dma)
1692 			dmaengine_terminate_all(dma->chan_using);
1693 		ret = -ETIMEDOUT;
1694 		goto pm_free;
1695 	}
1696 
1697 	/* Check PEC */
1698 	if ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK && read_write) {
1699 		ret = stm32f7_i2c_smbus_check_pec(i2c_dev);
1700 		if (ret)
1701 			goto pm_free;
1702 	}
1703 
1704 	if (read_write && size != I2C_SMBUS_QUICK) {
1705 		switch (size) {
1706 		case I2C_SMBUS_BYTE:
1707 		case I2C_SMBUS_BYTE_DATA:
1708 			data->byte = f7_msg->smbus_buf[0];
1709 		break;
1710 		case I2C_SMBUS_WORD_DATA:
1711 		case I2C_SMBUS_PROC_CALL:
1712 			data->word = f7_msg->smbus_buf[0] |
1713 				(f7_msg->smbus_buf[1] << 8);
1714 		break;
1715 		case I2C_SMBUS_BLOCK_DATA:
1716 		case I2C_SMBUS_BLOCK_PROC_CALL:
1717 		for (i = 0; i <= f7_msg->smbus_buf[0]; i++)
1718 			data->block[i] = f7_msg->smbus_buf[i];
1719 		break;
1720 		default:
1721 			dev_err(dev, "Unsupported smbus transaction\n");
1722 			ret = -EINVAL;
1723 		}
1724 	}
1725 
1726 pm_free:
1727 	pm_runtime_mark_last_busy(dev);
1728 	pm_runtime_put_autosuspend(dev);
1729 	return ret;
1730 }
1731 
1732 static void stm32f7_i2c_enable_wakeup(struct stm32f7_i2c_dev *i2c_dev,
1733 				      bool enable)
1734 {
1735 	void __iomem *base = i2c_dev->base;
1736 	u32 mask = STM32F7_I2C_CR1_WUPEN;
1737 
1738 	if (!i2c_dev->wakeup_src)
1739 		return;
1740 
1741 	if (enable) {
1742 		device_set_wakeup_enable(i2c_dev->dev, true);
1743 		stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
1744 	} else {
1745 		device_set_wakeup_enable(i2c_dev->dev, false);
1746 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, mask);
1747 	}
1748 }
1749 
1750 static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
1751 {
1752 	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(slave->adapter);
1753 	void __iomem *base = i2c_dev->base;
1754 	struct device *dev = i2c_dev->dev;
1755 	u32 oar1, oar2, mask;
1756 	int id, ret;
1757 
1758 	if (slave->flags & I2C_CLIENT_PEC) {
1759 		dev_err(dev, "SMBus PEC not supported in slave mode\n");
1760 		return -EINVAL;
1761 	}
1762 
1763 	if (stm32f7_i2c_is_slave_busy(i2c_dev)) {
1764 		dev_err(dev, "Too much slave registered\n");
1765 		return -EBUSY;
1766 	}
1767 
1768 	ret = stm32f7_i2c_get_free_slave_id(i2c_dev, slave, &id);
1769 	if (ret)
1770 		return ret;
1771 
1772 	ret = pm_runtime_get_sync(dev);
1773 	if (ret < 0)
1774 		return ret;
1775 
1776 	if (!stm32f7_i2c_is_slave_registered(i2c_dev))
1777 		stm32f7_i2c_enable_wakeup(i2c_dev, true);
1778 
1779 	if (id == 0) {
1780 		/* Configure Own Address 1 */
1781 		oar1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR1);
1782 		oar1 &= ~STM32F7_I2C_OAR1_MASK;
1783 		if (slave->flags & I2C_CLIENT_TEN) {
1784 			oar1 |= STM32F7_I2C_OAR1_OA1_10(slave->addr);
1785 			oar1 |= STM32F7_I2C_OAR1_OA1MODE;
1786 		} else {
1787 			oar1 |= STM32F7_I2C_OAR1_OA1_7(slave->addr);
1788 		}
1789 		oar1 |= STM32F7_I2C_OAR1_OA1EN;
1790 		i2c_dev->slave[id] = slave;
1791 		writel_relaxed(oar1, i2c_dev->base + STM32F7_I2C_OAR1);
1792 	} else if (id == 1) {
1793 		/* Configure Own Address 2 */
1794 		oar2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR2);
1795 		oar2 &= ~STM32F7_I2C_OAR2_MASK;
1796 		if (slave->flags & I2C_CLIENT_TEN) {
1797 			ret = -EOPNOTSUPP;
1798 			goto pm_free;
1799 		}
1800 
1801 		oar2 |= STM32F7_I2C_OAR2_OA2_7(slave->addr);
1802 		oar2 |= STM32F7_I2C_OAR2_OA2EN;
1803 		i2c_dev->slave[id] = slave;
1804 		writel_relaxed(oar2, i2c_dev->base + STM32F7_I2C_OAR2);
1805 	} else {
1806 		ret = -ENODEV;
1807 		goto pm_free;
1808 	}
1809 
1810 	/* Enable ACK */
1811 	stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR2, STM32F7_I2C_CR2_NACK);
1812 
1813 	/* Enable Address match interrupt, error interrupt and enable I2C  */
1814 	mask = STM32F7_I2C_CR1_ADDRIE | STM32F7_I2C_CR1_ERRIE |
1815 		STM32F7_I2C_CR1_PE;
1816 	stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
1817 
1818 	ret = 0;
1819 pm_free:
1820 	if (!stm32f7_i2c_is_slave_registered(i2c_dev))
1821 		stm32f7_i2c_enable_wakeup(i2c_dev, false);
1822 
1823 	pm_runtime_mark_last_busy(dev);
1824 	pm_runtime_put_autosuspend(dev);
1825 
1826 	return ret;
1827 }
1828 
1829 static int stm32f7_i2c_unreg_slave(struct i2c_client *slave)
1830 {
1831 	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(slave->adapter);
1832 	void __iomem *base = i2c_dev->base;
1833 	u32 mask;
1834 	int id, ret;
1835 
1836 	ret = stm32f7_i2c_get_slave_id(i2c_dev, slave, &id);
1837 	if (ret)
1838 		return ret;
1839 
1840 	WARN_ON(!i2c_dev->slave[id]);
1841 
1842 	ret = pm_runtime_get_sync(i2c_dev->dev);
1843 	if (ret < 0)
1844 		return ret;
1845 
1846 	if (id == 0) {
1847 		mask = STM32F7_I2C_OAR1_OA1EN;
1848 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR1, mask);
1849 	} else {
1850 		mask = STM32F7_I2C_OAR2_OA2EN;
1851 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR2, mask);
1852 	}
1853 
1854 	i2c_dev->slave[id] = NULL;
1855 
1856 	if (!stm32f7_i2c_is_slave_registered(i2c_dev)) {
1857 		stm32f7_i2c_disable_irq(i2c_dev, STM32F7_I2C_ALL_IRQ_MASK);
1858 		stm32f7_i2c_enable_wakeup(i2c_dev, false);
1859 	}
1860 
1861 	pm_runtime_mark_last_busy(i2c_dev->dev);
1862 	pm_runtime_put_autosuspend(i2c_dev->dev);
1863 
1864 	return 0;
1865 }
1866 
1867 static int stm32f7_i2c_write_fm_plus_bits(struct stm32f7_i2c_dev *i2c_dev,
1868 					  bool enable)
1869 {
1870 	int ret;
1871 
1872 	if (i2c_dev->bus_rate <= I2C_MAX_FAST_MODE_FREQ ||
1873 	    IS_ERR_OR_NULL(i2c_dev->regmap))
1874 		/* Optional */
1875 		return 0;
1876 
1877 	if (i2c_dev->fmp_sreg == i2c_dev->fmp_creg)
1878 		ret = regmap_update_bits(i2c_dev->regmap,
1879 					 i2c_dev->fmp_sreg,
1880 					 i2c_dev->fmp_mask,
1881 					 enable ? i2c_dev->fmp_mask : 0);
1882 	else
1883 		ret = regmap_write(i2c_dev->regmap,
1884 				   enable ? i2c_dev->fmp_sreg :
1885 					    i2c_dev->fmp_creg,
1886 				   i2c_dev->fmp_mask);
1887 
1888 	return ret;
1889 }
1890 
1891 static int stm32f7_i2c_setup_fm_plus_bits(struct platform_device *pdev,
1892 					  struct stm32f7_i2c_dev *i2c_dev)
1893 {
1894 	struct device_node *np = pdev->dev.of_node;
1895 	int ret;
1896 
1897 	i2c_dev->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg-fmp");
1898 	if (IS_ERR(i2c_dev->regmap))
1899 		/* Optional */
1900 		return 0;
1901 
1902 	ret = of_property_read_u32_index(np, "st,syscfg-fmp", 1,
1903 					 &i2c_dev->fmp_sreg);
1904 	if (ret)
1905 		return ret;
1906 
1907 	i2c_dev->fmp_creg = i2c_dev->fmp_sreg +
1908 			       i2c_dev->setup.fmp_clr_offset;
1909 
1910 	return of_property_read_u32_index(np, "st,syscfg-fmp", 2,
1911 					  &i2c_dev->fmp_mask);
1912 }
1913 
1914 static u32 stm32f7_i2c_func(struct i2c_adapter *adap)
1915 {
1916 	return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SLAVE |
1917 		I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
1918 		I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
1919 		I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
1920 		I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_PEC |
1921 		I2C_FUNC_SMBUS_I2C_BLOCK;
1922 }
1923 
1924 static const struct i2c_algorithm stm32f7_i2c_algo = {
1925 	.master_xfer = stm32f7_i2c_xfer,
1926 	.smbus_xfer = stm32f7_i2c_smbus_xfer,
1927 	.functionality = stm32f7_i2c_func,
1928 	.reg_slave = stm32f7_i2c_reg_slave,
1929 	.unreg_slave = stm32f7_i2c_unreg_slave,
1930 };
1931 
1932 static int stm32f7_i2c_probe(struct platform_device *pdev)
1933 {
1934 	struct stm32f7_i2c_dev *i2c_dev;
1935 	const struct stm32f7_i2c_setup *setup;
1936 	struct resource *res;
1937 	struct i2c_adapter *adap;
1938 	struct reset_control *rst;
1939 	dma_addr_t phy_addr;
1940 	int irq_error, irq_event, ret;
1941 
1942 	i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
1943 	if (!i2c_dev)
1944 		return -ENOMEM;
1945 
1946 	i2c_dev->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
1947 	if (IS_ERR(i2c_dev->base))
1948 		return PTR_ERR(i2c_dev->base);
1949 	phy_addr = (dma_addr_t)res->start;
1950 
1951 	irq_event = platform_get_irq(pdev, 0);
1952 	if (irq_event <= 0) {
1953 		if (irq_event != -EPROBE_DEFER)
1954 			dev_err(&pdev->dev, "Failed to get IRQ event: %d\n",
1955 				irq_event);
1956 		return irq_event ? : -ENOENT;
1957 	}
1958 
1959 	irq_error = platform_get_irq(pdev, 1);
1960 	if (irq_error <= 0) {
1961 		if (irq_error != -EPROBE_DEFER)
1962 			dev_err(&pdev->dev, "Failed to get IRQ error: %d\n",
1963 				irq_error);
1964 		return irq_error ? : -ENOENT;
1965 	}
1966 
1967 	i2c_dev->wakeup_src = of_property_read_bool(pdev->dev.of_node,
1968 						    "wakeup-source");
1969 
1970 	i2c_dev->clk = devm_clk_get(&pdev->dev, NULL);
1971 	if (IS_ERR(i2c_dev->clk)) {
1972 		if (PTR_ERR(i2c_dev->clk) != -EPROBE_DEFER)
1973 			dev_err(&pdev->dev, "Failed to get controller clock\n");
1974 		return PTR_ERR(i2c_dev->clk);
1975 	}
1976 
1977 	ret = clk_prepare_enable(i2c_dev->clk);
1978 	if (ret) {
1979 		dev_err(&pdev->dev, "Failed to prepare_enable clock\n");
1980 		return ret;
1981 	}
1982 
1983 	rst = devm_reset_control_get(&pdev->dev, NULL);
1984 	if (IS_ERR(rst)) {
1985 		ret = PTR_ERR(rst);
1986 		if (ret != -EPROBE_DEFER)
1987 			dev_err(&pdev->dev, "Error: Missing reset ctrl\n");
1988 
1989 		goto clk_free;
1990 	}
1991 	reset_control_assert(rst);
1992 	udelay(2);
1993 	reset_control_deassert(rst);
1994 
1995 	i2c_dev->dev = &pdev->dev;
1996 
1997 	ret = devm_request_threaded_irq(&pdev->dev, irq_event,
1998 					stm32f7_i2c_isr_event,
1999 					stm32f7_i2c_isr_event_thread,
2000 					IRQF_ONESHOT,
2001 					pdev->name, i2c_dev);
2002 	if (ret) {
2003 		dev_err(&pdev->dev, "Failed to request irq event %i\n",
2004 			irq_event);
2005 		goto clk_free;
2006 	}
2007 
2008 	ret = devm_request_irq(&pdev->dev, irq_error, stm32f7_i2c_isr_error, 0,
2009 			       pdev->name, i2c_dev);
2010 	if (ret) {
2011 		dev_err(&pdev->dev, "Failed to request irq error %i\n",
2012 			irq_error);
2013 		goto clk_free;
2014 	}
2015 
2016 	setup = of_device_get_match_data(&pdev->dev);
2017 	if (!setup) {
2018 		dev_err(&pdev->dev, "Can't get device data\n");
2019 		ret = -ENODEV;
2020 		goto clk_free;
2021 	}
2022 	i2c_dev->setup = *setup;
2023 
2024 	ret = stm32f7_i2c_setup_timing(i2c_dev, &i2c_dev->setup);
2025 	if (ret)
2026 		goto clk_free;
2027 
2028 	/* Setup Fast mode plus if necessary */
2029 	if (i2c_dev->bus_rate > I2C_MAX_FAST_MODE_FREQ) {
2030 		ret = stm32f7_i2c_setup_fm_plus_bits(pdev, i2c_dev);
2031 		if (ret)
2032 			goto clk_free;
2033 		ret = stm32f7_i2c_write_fm_plus_bits(i2c_dev, true);
2034 		if (ret)
2035 			goto clk_free;
2036 	}
2037 
2038 	adap = &i2c_dev->adap;
2039 	i2c_set_adapdata(adap, i2c_dev);
2040 	snprintf(adap->name, sizeof(adap->name), "STM32F7 I2C(%pa)",
2041 		 &res->start);
2042 	adap->owner = THIS_MODULE;
2043 	adap->timeout = 2 * HZ;
2044 	adap->retries = 3;
2045 	adap->algo = &stm32f7_i2c_algo;
2046 	adap->dev.parent = &pdev->dev;
2047 	adap->dev.of_node = pdev->dev.of_node;
2048 
2049 	init_completion(&i2c_dev->complete);
2050 
2051 	/* Init DMA config if supported */
2052 	i2c_dev->dma = stm32_i2c_dma_request(i2c_dev->dev, phy_addr,
2053 					     STM32F7_I2C_TXDR,
2054 					     STM32F7_I2C_RXDR);
2055 	if (PTR_ERR(i2c_dev->dma) == -ENODEV)
2056 		i2c_dev->dma = NULL;
2057 	else if (IS_ERR(i2c_dev->dma)) {
2058 		ret = PTR_ERR(i2c_dev->dma);
2059 		if (ret != -EPROBE_DEFER)
2060 			dev_err(&pdev->dev,
2061 				"Failed to request dma error %i\n", ret);
2062 		goto fmp_clear;
2063 	}
2064 
2065 	if (i2c_dev->wakeup_src) {
2066 		device_set_wakeup_capable(i2c_dev->dev, true);
2067 
2068 		ret = dev_pm_set_wake_irq(i2c_dev->dev, irq_event);
2069 		if (ret) {
2070 			dev_err(i2c_dev->dev, "Failed to set wake up irq\n");
2071 			goto clr_wakeup_capable;
2072 		}
2073 	}
2074 
2075 	platform_set_drvdata(pdev, i2c_dev);
2076 
2077 	pm_runtime_set_autosuspend_delay(i2c_dev->dev,
2078 					 STM32F7_AUTOSUSPEND_DELAY);
2079 	pm_runtime_use_autosuspend(i2c_dev->dev);
2080 	pm_runtime_set_active(i2c_dev->dev);
2081 	pm_runtime_enable(i2c_dev->dev);
2082 
2083 	pm_runtime_get_noresume(&pdev->dev);
2084 
2085 	stm32f7_i2c_hw_config(i2c_dev);
2086 
2087 	ret = i2c_add_adapter(adap);
2088 	if (ret)
2089 		goto pm_disable;
2090 
2091 	dev_info(i2c_dev->dev, "STM32F7 I2C-%d bus adapter\n", adap->nr);
2092 
2093 	pm_runtime_mark_last_busy(i2c_dev->dev);
2094 	pm_runtime_put_autosuspend(i2c_dev->dev);
2095 
2096 	return 0;
2097 
2098 pm_disable:
2099 	pm_runtime_put_noidle(i2c_dev->dev);
2100 	pm_runtime_disable(i2c_dev->dev);
2101 	pm_runtime_set_suspended(i2c_dev->dev);
2102 	pm_runtime_dont_use_autosuspend(i2c_dev->dev);
2103 
2104 	if (i2c_dev->wakeup_src)
2105 		dev_pm_clear_wake_irq(i2c_dev->dev);
2106 
2107 clr_wakeup_capable:
2108 	if (i2c_dev->wakeup_src)
2109 		device_set_wakeup_capable(i2c_dev->dev, false);
2110 
2111 	if (i2c_dev->dma) {
2112 		stm32_i2c_dma_free(i2c_dev->dma);
2113 		i2c_dev->dma = NULL;
2114 	}
2115 
2116 fmp_clear:
2117 	stm32f7_i2c_write_fm_plus_bits(i2c_dev, false);
2118 
2119 clk_free:
2120 	clk_disable_unprepare(i2c_dev->clk);
2121 
2122 	return ret;
2123 }
2124 
2125 static int stm32f7_i2c_remove(struct platform_device *pdev)
2126 {
2127 	struct stm32f7_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
2128 
2129 	i2c_del_adapter(&i2c_dev->adap);
2130 	pm_runtime_get_sync(i2c_dev->dev);
2131 
2132 	if (i2c_dev->wakeup_src) {
2133 		dev_pm_clear_wake_irq(i2c_dev->dev);
2134 		/*
2135 		 * enforce that wakeup is disabled and that the device
2136 		 * is marked as non wakeup capable
2137 		 */
2138 		device_init_wakeup(i2c_dev->dev, false);
2139 	}
2140 
2141 	pm_runtime_put_noidle(i2c_dev->dev);
2142 	pm_runtime_disable(i2c_dev->dev);
2143 	pm_runtime_set_suspended(i2c_dev->dev);
2144 	pm_runtime_dont_use_autosuspend(i2c_dev->dev);
2145 
2146 	if (i2c_dev->dma) {
2147 		stm32_i2c_dma_free(i2c_dev->dma);
2148 		i2c_dev->dma = NULL;
2149 	}
2150 
2151 	stm32f7_i2c_write_fm_plus_bits(i2c_dev, false);
2152 
2153 	clk_disable_unprepare(i2c_dev->clk);
2154 
2155 	return 0;
2156 }
2157 
2158 static int __maybe_unused stm32f7_i2c_runtime_suspend(struct device *dev)
2159 {
2160 	struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
2161 
2162 	if (!stm32f7_i2c_is_slave_registered(i2c_dev))
2163 		clk_disable_unprepare(i2c_dev->clk);
2164 
2165 	return 0;
2166 }
2167 
2168 static int __maybe_unused stm32f7_i2c_runtime_resume(struct device *dev)
2169 {
2170 	struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
2171 	int ret;
2172 
2173 	if (!stm32f7_i2c_is_slave_registered(i2c_dev)) {
2174 		ret = clk_prepare_enable(i2c_dev->clk);
2175 		if (ret) {
2176 			dev_err(dev, "failed to prepare_enable clock\n");
2177 			return ret;
2178 		}
2179 	}
2180 
2181 	return 0;
2182 }
2183 
2184 #ifdef CONFIG_PM_SLEEP
2185 static int stm32f7_i2c_regs_backup(struct stm32f7_i2c_dev *i2c_dev)
2186 {
2187 	int ret;
2188 	struct stm32f7_i2c_regs *backup_regs = &i2c_dev->backup_regs;
2189 
2190 	ret = pm_runtime_get_sync(i2c_dev->dev);
2191 	if (ret < 0)
2192 		return ret;
2193 
2194 	backup_regs->cr1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR1);
2195 	backup_regs->cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
2196 	backup_regs->oar1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR1);
2197 	backup_regs->oar2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR2);
2198 	backup_regs->tmgr = readl_relaxed(i2c_dev->base + STM32F7_I2C_TIMINGR);
2199 	stm32f7_i2c_write_fm_plus_bits(i2c_dev, false);
2200 
2201 	pm_runtime_put_sync(i2c_dev->dev);
2202 
2203 	return ret;
2204 }
2205 
2206 static int stm32f7_i2c_regs_restore(struct stm32f7_i2c_dev *i2c_dev)
2207 {
2208 	u32 cr1;
2209 	int ret;
2210 	struct stm32f7_i2c_regs *backup_regs = &i2c_dev->backup_regs;
2211 
2212 	ret = pm_runtime_get_sync(i2c_dev->dev);
2213 	if (ret < 0)
2214 		return ret;
2215 
2216 	cr1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR1);
2217 	if (cr1 & STM32F7_I2C_CR1_PE)
2218 		stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1,
2219 				     STM32F7_I2C_CR1_PE);
2220 
2221 	writel_relaxed(backup_regs->tmgr, i2c_dev->base + STM32F7_I2C_TIMINGR);
2222 	writel_relaxed(backup_regs->cr1 & ~STM32F7_I2C_CR1_PE,
2223 		       i2c_dev->base + STM32F7_I2C_CR1);
2224 	if (backup_regs->cr1 & STM32F7_I2C_CR1_PE)
2225 		stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,
2226 				     STM32F7_I2C_CR1_PE);
2227 	writel_relaxed(backup_regs->cr2, i2c_dev->base + STM32F7_I2C_CR2);
2228 	writel_relaxed(backup_regs->oar1, i2c_dev->base + STM32F7_I2C_OAR1);
2229 	writel_relaxed(backup_regs->oar2, i2c_dev->base + STM32F7_I2C_OAR2);
2230 	stm32f7_i2c_write_fm_plus_bits(i2c_dev, true);
2231 
2232 	pm_runtime_put_sync(i2c_dev->dev);
2233 
2234 	return ret;
2235 }
2236 
2237 static int stm32f7_i2c_suspend(struct device *dev)
2238 {
2239 	struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
2240 	int ret;
2241 
2242 	i2c_mark_adapter_suspended(&i2c_dev->adap);
2243 
2244 	if (!device_may_wakeup(dev) && !dev->power.wakeup_path) {
2245 		ret = stm32f7_i2c_regs_backup(i2c_dev);
2246 		if (ret < 0) {
2247 			i2c_mark_adapter_resumed(&i2c_dev->adap);
2248 			return ret;
2249 		}
2250 
2251 		pinctrl_pm_select_sleep_state(dev);
2252 		pm_runtime_force_suspend(dev);
2253 	}
2254 
2255 	return 0;
2256 }
2257 
2258 static int stm32f7_i2c_resume(struct device *dev)
2259 {
2260 	struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
2261 	int ret;
2262 
2263 	if (!device_may_wakeup(dev) && !dev->power.wakeup_path) {
2264 		ret = pm_runtime_force_resume(dev);
2265 		if (ret < 0)
2266 			return ret;
2267 		pinctrl_pm_select_default_state(dev);
2268 
2269 		ret = stm32f7_i2c_regs_restore(i2c_dev);
2270 		if (ret < 0)
2271 			return ret;
2272 	}
2273 
2274 	i2c_mark_adapter_resumed(&i2c_dev->adap);
2275 
2276 	return 0;
2277 }
2278 #endif
2279 
2280 static const struct dev_pm_ops stm32f7_i2c_pm_ops = {
2281 	SET_RUNTIME_PM_OPS(stm32f7_i2c_runtime_suspend,
2282 			   stm32f7_i2c_runtime_resume, NULL)
2283 	SET_SYSTEM_SLEEP_PM_OPS(stm32f7_i2c_suspend, stm32f7_i2c_resume)
2284 };
2285 
2286 static const struct of_device_id stm32f7_i2c_match[] = {
2287 	{ .compatible = "st,stm32f7-i2c", .data = &stm32f7_setup},
2288 	{ .compatible = "st,stm32mp15-i2c", .data = &stm32mp15_setup},
2289 	{},
2290 };
2291 MODULE_DEVICE_TABLE(of, stm32f7_i2c_match);
2292 
2293 static struct platform_driver stm32f7_i2c_driver = {
2294 	.driver = {
2295 		.name = "stm32f7-i2c",
2296 		.of_match_table = stm32f7_i2c_match,
2297 		.pm = &stm32f7_i2c_pm_ops,
2298 	},
2299 	.probe = stm32f7_i2c_probe,
2300 	.remove = stm32f7_i2c_remove,
2301 };
2302 
2303 module_platform_driver(stm32f7_i2c_driver);
2304 
2305 MODULE_AUTHOR("M'boumba Cedric Madianga <cedric.madianga@gmail.com>");
2306 MODULE_DESCRIPTION("STMicroelectronics STM32F7 I2C driver");
2307 MODULE_LICENSE("GPL v2");
2308