1 /*
2  * Synopsys DesignWare I2C adapter driver.
3  *
4  * Based on the TI DAVINCI I2C adapter driver.
5  *
6  * Copyright (C) 2006 Texas Instruments.
7  * Copyright (C) 2007 MontaVista Software Inc.
8  * Copyright (C) 2009 Provigent Ltd.
9  *
10  * ----------------------------------------------------------------------------
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  * ----------------------------------------------------------------------------
22  *
23  */
24 
25 #include <linux/i2c.h>
26 #include <linux/pm_qos.h>
27 
28 #define DW_IC_DEFAULT_FUNCTIONALITY (I2C_FUNC_I2C |			\
29 					I2C_FUNC_SMBUS_BYTE |		\
30 					I2C_FUNC_SMBUS_BYTE_DATA |	\
31 					I2C_FUNC_SMBUS_WORD_DATA |	\
32 					I2C_FUNC_SMBUS_BLOCK_DATA |	\
33 					I2C_FUNC_SMBUS_I2C_BLOCK)
34 
35 #define DW_IC_CON_MASTER		0x1
36 #define DW_IC_CON_SPEED_STD		0x2
37 #define DW_IC_CON_SPEED_FAST		0x4
38 #define DW_IC_CON_SPEED_HIGH		0x6
39 #define DW_IC_CON_SPEED_MASK		0x6
40 #define DW_IC_CON_10BITADDR_SLAVE		0x8
41 #define DW_IC_CON_10BITADDR_MASTER	0x10
42 #define DW_IC_CON_RESTART_EN		0x20
43 #define DW_IC_CON_SLAVE_DISABLE		0x40
44 #define DW_IC_CON_STOP_DET_IFADDRESSED		0x80
45 #define DW_IC_CON_TX_EMPTY_CTRL		0x100
46 #define DW_IC_CON_RX_FIFO_FULL_HLD_CTRL		0x200
47 
48 /*
49  * Registers offset
50  */
51 #define DW_IC_CON		0x0
52 #define DW_IC_TAR		0x4
53 #define DW_IC_SAR		0x8
54 #define DW_IC_DATA_CMD		0x10
55 #define DW_IC_SS_SCL_HCNT	0x14
56 #define DW_IC_SS_SCL_LCNT	0x18
57 #define DW_IC_FS_SCL_HCNT	0x1c
58 #define DW_IC_FS_SCL_LCNT	0x20
59 #define DW_IC_HS_SCL_HCNT	0x24
60 #define DW_IC_HS_SCL_LCNT	0x28
61 #define DW_IC_INTR_STAT		0x2c
62 #define DW_IC_INTR_MASK		0x30
63 #define DW_IC_RAW_INTR_STAT	0x34
64 #define DW_IC_RX_TL		0x38
65 #define DW_IC_TX_TL		0x3c
66 #define DW_IC_CLR_INTR		0x40
67 #define DW_IC_CLR_RX_UNDER	0x44
68 #define DW_IC_CLR_RX_OVER	0x48
69 #define DW_IC_CLR_TX_OVER	0x4c
70 #define DW_IC_CLR_RD_REQ	0x50
71 #define DW_IC_CLR_TX_ABRT	0x54
72 #define DW_IC_CLR_RX_DONE	0x58
73 #define DW_IC_CLR_ACTIVITY	0x5c
74 #define DW_IC_CLR_STOP_DET	0x60
75 #define DW_IC_CLR_START_DET	0x64
76 #define DW_IC_CLR_GEN_CALL	0x68
77 #define DW_IC_ENABLE		0x6c
78 #define DW_IC_STATUS		0x70
79 #define DW_IC_TXFLR		0x74
80 #define DW_IC_RXFLR		0x78
81 #define DW_IC_SDA_HOLD		0x7c
82 #define DW_IC_TX_ABRT_SOURCE	0x80
83 #define DW_IC_ENABLE_STATUS	0x9c
84 #define DW_IC_CLR_RESTART_DET	0xa8
85 #define DW_IC_COMP_PARAM_1	0xf4
86 #define DW_IC_COMP_VERSION	0xf8
87 #define DW_IC_SDA_HOLD_MIN_VERS	0x3131312A
88 #define DW_IC_COMP_TYPE		0xfc
89 #define DW_IC_COMP_TYPE_VALUE	0x44570140
90 
91 #define DW_IC_INTR_RX_UNDER	0x001
92 #define DW_IC_INTR_RX_OVER	0x002
93 #define DW_IC_INTR_RX_FULL	0x004
94 #define DW_IC_INTR_TX_OVER	0x008
95 #define DW_IC_INTR_TX_EMPTY	0x010
96 #define DW_IC_INTR_RD_REQ	0x020
97 #define DW_IC_INTR_TX_ABRT	0x040
98 #define DW_IC_INTR_RX_DONE	0x080
99 #define DW_IC_INTR_ACTIVITY	0x100
100 #define DW_IC_INTR_STOP_DET	0x200
101 #define DW_IC_INTR_START_DET	0x400
102 #define DW_IC_INTR_GEN_CALL	0x800
103 #define DW_IC_INTR_RESTART_DET	0x1000
104 
105 #define DW_IC_INTR_DEFAULT_MASK		(DW_IC_INTR_RX_FULL | \
106 					 DW_IC_INTR_TX_ABRT | \
107 					 DW_IC_INTR_STOP_DET)
108 #define DW_IC_INTR_MASTER_MASK		(DW_IC_INTR_DEFAULT_MASK | \
109 					 DW_IC_INTR_TX_EMPTY)
110 #define DW_IC_INTR_SLAVE_MASK		(DW_IC_INTR_DEFAULT_MASK | \
111 					 DW_IC_INTR_RX_DONE | \
112 					 DW_IC_INTR_RX_UNDER | \
113 					 DW_IC_INTR_RD_REQ)
114 
115 #define DW_IC_STATUS_ACTIVITY		0x1
116 #define DW_IC_STATUS_TFE		BIT(2)
117 #define DW_IC_STATUS_MASTER_ACTIVITY	BIT(5)
118 #define DW_IC_STATUS_SLAVE_ACTIVITY	BIT(6)
119 
120 #define DW_IC_SDA_HOLD_RX_SHIFT		16
121 #define DW_IC_SDA_HOLD_RX_MASK		GENMASK(23, DW_IC_SDA_HOLD_RX_SHIFT)
122 
123 #define DW_IC_ERR_TX_ABRT	0x1
124 
125 #define DW_IC_TAR_10BITADDR_MASTER BIT(12)
126 
127 #define DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH	(BIT(2) | BIT(3))
128 #define DW_IC_COMP_PARAM_1_SPEED_MODE_MASK	GENMASK(3, 2)
129 
130 /*
131  * status codes
132  */
133 #define STATUS_IDLE			0x0
134 #define STATUS_WRITE_IN_PROGRESS	0x1
135 #define STATUS_READ_IN_PROGRESS		0x2
136 
137 #define TIMEOUT			20 /* ms */
138 
139 /*
140  * operation modes
141  */
142 #define DW_IC_MASTER		0
143 #define DW_IC_SLAVE		1
144 
145 /*
146  * Hardware abort codes from the DW_IC_TX_ABRT_SOURCE register
147  *
148  * Only expected abort codes are listed here
149  * refer to the datasheet for the full list
150  */
151 #define ABRT_7B_ADDR_NOACK	0
152 #define ABRT_10ADDR1_NOACK	1
153 #define ABRT_10ADDR2_NOACK	2
154 #define ABRT_TXDATA_NOACK	3
155 #define ABRT_GCALL_NOACK	4
156 #define ABRT_GCALL_READ		5
157 #define ABRT_SBYTE_ACKDET	7
158 #define ABRT_SBYTE_NORSTRT	9
159 #define ABRT_10B_RD_NORSTRT	10
160 #define ABRT_MASTER_DIS		11
161 #define ARB_LOST		12
162 #define ABRT_SLAVE_FLUSH_TXFIFO	13
163 #define ABRT_SLAVE_ARBLOST	14
164 #define ABRT_SLAVE_RD_INTX	15
165 
166 #define DW_IC_TX_ABRT_7B_ADDR_NOACK	(1UL << ABRT_7B_ADDR_NOACK)
167 #define DW_IC_TX_ABRT_10ADDR1_NOACK	(1UL << ABRT_10ADDR1_NOACK)
168 #define DW_IC_TX_ABRT_10ADDR2_NOACK	(1UL << ABRT_10ADDR2_NOACK)
169 #define DW_IC_TX_ABRT_TXDATA_NOACK	(1UL << ABRT_TXDATA_NOACK)
170 #define DW_IC_TX_ABRT_GCALL_NOACK	(1UL << ABRT_GCALL_NOACK)
171 #define DW_IC_TX_ABRT_GCALL_READ	(1UL << ABRT_GCALL_READ)
172 #define DW_IC_TX_ABRT_SBYTE_ACKDET	(1UL << ABRT_SBYTE_ACKDET)
173 #define DW_IC_TX_ABRT_SBYTE_NORSTRT	(1UL << ABRT_SBYTE_NORSTRT)
174 #define DW_IC_TX_ABRT_10B_RD_NORSTRT	(1UL << ABRT_10B_RD_NORSTRT)
175 #define DW_IC_TX_ABRT_MASTER_DIS	(1UL << ABRT_MASTER_DIS)
176 #define DW_IC_TX_ARB_LOST		(1UL << ARB_LOST)
177 #define DW_IC_RX_ABRT_SLAVE_RD_INTX	(1UL << ABRT_SLAVE_RD_INTX)
178 #define DW_IC_RX_ABRT_SLAVE_ARBLOST	(1UL << ABRT_SLAVE_ARBLOST)
179 #define DW_IC_RX_ABRT_SLAVE_FLUSH_TXFIFO	(1UL << ABRT_SLAVE_FLUSH_TXFIFO)
180 
181 #define DW_IC_TX_ABRT_NOACK		(DW_IC_TX_ABRT_7B_ADDR_NOACK | \
182 					 DW_IC_TX_ABRT_10ADDR1_NOACK | \
183 					 DW_IC_TX_ABRT_10ADDR2_NOACK | \
184 					 DW_IC_TX_ABRT_TXDATA_NOACK | \
185 					 DW_IC_TX_ABRT_GCALL_NOACK)
186 
187 
188 /**
189  * struct dw_i2c_dev - private i2c-designware data
190  * @dev: driver model device node
191  * @base: IO registers pointer
192  * @cmd_complete: tx completion indicator
193  * @clk: input reference clock
194  * @slave: represent an I2C slave device
195  * @cmd_err: run time hadware error code
196  * @msgs: points to an array of messages currently being transferred
197  * @msgs_num: the number of elements in msgs
198  * @msg_write_idx: the element index of the current tx message in the msgs
199  *	array
200  * @tx_buf_len: the length of the current tx buffer
201  * @tx_buf: the current tx buffer
202  * @msg_read_idx: the element index of the current rx message in the msgs
203  *	array
204  * @rx_buf_len: the length of the current rx buffer
205  * @rx_buf: the current rx buffer
206  * @msg_err: error status of the current transfer
207  * @status: i2c master status, one of STATUS_*
208  * @abort_source: copy of the TX_ABRT_SOURCE register
209  * @irq: interrupt number for the i2c master
210  * @adapter: i2c subsystem adapter node
211  * @slave_cfg: configuration for the slave device
212  * @tx_fifo_depth: depth of the hardware tx fifo
213  * @rx_fifo_depth: depth of the hardware rx fifo
214  * @rx_outstanding: current master-rx elements in tx fifo
215  * @clk_freq: bus clock frequency
216  * @ss_hcnt: standard speed HCNT value
217  * @ss_lcnt: standard speed LCNT value
218  * @fs_hcnt: fast speed HCNT value
219  * @fs_lcnt: fast speed LCNT value
220  * @fp_hcnt: fast plus HCNT value
221  * @fp_lcnt: fast plus LCNT value
222  * @hs_hcnt: high speed HCNT value
223  * @hs_lcnt: high speed LCNT value
224  * @pm_qos: pm_qos_request used while holding a hardware lock on the bus
225  * @acquire_lock: function to acquire a hardware lock on the bus
226  * @release_lock: function to release a hardware lock on the bus
227  * @pm_disabled: true if power-management should be disabled for this i2c-bus
228  * @disable: function to disable the controller
229  * @disable_int: function to disable all interrupts
230  * @init: function to initialize the I2C hardware
231  * @mode: operation mode - DW_IC_MASTER or DW_IC_SLAVE
232  *
233  * HCNT and LCNT parameters can be used if the platform knows more accurate
234  * values than the one computed based only on the input clock frequency.
235  * Leave them to be %0 if not used.
236  */
237 struct dw_i2c_dev {
238 	struct device		*dev;
239 	void __iomem		*base;
240 	struct completion	cmd_complete;
241 	struct clk		*clk;
242 	struct reset_control	*rst;
243 	struct i2c_client		*slave;
244 	u32			(*get_clk_rate_khz) (struct dw_i2c_dev *dev);
245 	struct dw_pci_controller *controller;
246 	int			cmd_err;
247 	struct i2c_msg		*msgs;
248 	int			msgs_num;
249 	int			msg_write_idx;
250 	u32			tx_buf_len;
251 	u8			*tx_buf;
252 	int			msg_read_idx;
253 	u32			rx_buf_len;
254 	u8			*rx_buf;
255 	int			msg_err;
256 	unsigned int		status;
257 	u32			abort_source;
258 	int			irq;
259 	u32			flags;
260 	struct i2c_adapter	adapter;
261 	u32			functionality;
262 	u32			master_cfg;
263 	u32			slave_cfg;
264 	unsigned int		tx_fifo_depth;
265 	unsigned int		rx_fifo_depth;
266 	int			rx_outstanding;
267 	u32			clk_freq;
268 	u32			sda_hold_time;
269 	u32			sda_falling_time;
270 	u32			scl_falling_time;
271 	u16			ss_hcnt;
272 	u16			ss_lcnt;
273 	u16			fs_hcnt;
274 	u16			fs_lcnt;
275 	u16			fp_hcnt;
276 	u16			fp_lcnt;
277 	u16			hs_hcnt;
278 	u16			hs_lcnt;
279 	struct pm_qos_request	pm_qos;
280 	int			(*acquire_lock)(struct dw_i2c_dev *dev);
281 	void			(*release_lock)(struct dw_i2c_dev *dev);
282 	bool			pm_disabled;
283 	void			(*disable)(struct dw_i2c_dev *dev);
284 	void			(*disable_int)(struct dw_i2c_dev *dev);
285 	int			(*init)(struct dw_i2c_dev *dev);
286 	int			mode;
287 	struct i2c_bus_recovery_info rinfo;
288 };
289 
290 #define ACCESS_SWAP		0x00000001
291 #define ACCESS_16BIT		0x00000002
292 #define ACCESS_INTR_MASK	0x00000004
293 
294 #define MODEL_CHERRYTRAIL	0x00000100
295 
296 u32 dw_readl(struct dw_i2c_dev *dev, int offset);
297 void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset);
298 u32 i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset);
299 u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset);
300 unsigned long i2c_dw_clk_rate(struct dw_i2c_dev *dev);
301 int i2c_dw_prepare_clk(struct dw_i2c_dev *dev, bool prepare);
302 int i2c_dw_acquire_lock(struct dw_i2c_dev *dev);
303 void i2c_dw_release_lock(struct dw_i2c_dev *dev);
304 int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev);
305 int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev);
306 u32 i2c_dw_func(struct i2c_adapter *adap);
307 void i2c_dw_disable(struct dw_i2c_dev *dev);
308 void i2c_dw_disable_int(struct dw_i2c_dev *dev);
309 
310 static inline void __i2c_dw_enable(struct dw_i2c_dev *dev)
311 {
312 	dw_writel(dev, 1, DW_IC_ENABLE);
313 }
314 
315 static inline void __i2c_dw_disable_nowait(struct dw_i2c_dev *dev)
316 {
317 	dw_writel(dev, 0, DW_IC_ENABLE);
318 }
319 
320 void __i2c_dw_disable(struct dw_i2c_dev *dev);
321 
322 extern u32 i2c_dw_read_comp_param(struct dw_i2c_dev *dev);
323 extern int i2c_dw_probe(struct dw_i2c_dev *dev);
324 #if IS_ENABLED(CONFIG_I2C_DESIGNWARE_SLAVE)
325 extern int i2c_dw_probe_slave(struct dw_i2c_dev *dev);
326 #else
327 static inline int i2c_dw_probe_slave(struct dw_i2c_dev *dev) { return -EINVAL; }
328 #endif
329 
330 #if IS_ENABLED(CONFIG_I2C_DESIGNWARE_BAYTRAIL)
331 extern int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev);
332 extern void i2c_dw_remove_lock_support(struct dw_i2c_dev *dev);
333 #else
334 static inline int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) { return 0; }
335 static inline void i2c_dw_remove_lock_support(struct dw_i2c_dev *dev) {}
336 #endif
337