xref: /openbmc/linux/drivers/i2c/busses/i2c-mt65xx.c (revision 2540d3c9)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2014 MediaTek Inc.
4  * Author: Xudong Chen <xudong.chen@mediatek.com>
5  */
6 
7 #include <linux/clk.h>
8 #include <linux/completion.h>
9 #include <linux/delay.h>
10 #include <linux/device.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/err.h>
13 #include <linux/errno.h>
14 #include <linux/i2c.h>
15 #include <linux/init.h>
16 #include <linux/interrupt.h>
17 #include <linux/io.h>
18 #include <linux/iopoll.h>
19 #include <linux/kernel.h>
20 #include <linux/mm.h>
21 #include <linux/module.h>
22 #include <linux/of_address.h>
23 #include <linux/of_device.h>
24 #include <linux/of_irq.h>
25 #include <linux/platform_device.h>
26 #include <linux/scatterlist.h>
27 #include <linux/sched.h>
28 #include <linux/slab.h>
29 
30 #define I2C_RS_TRANSFER			(1 << 4)
31 #define I2C_ARB_LOST			(1 << 3)
32 #define I2C_HS_NACKERR			(1 << 2)
33 #define I2C_ACKERR			(1 << 1)
34 #define I2C_TRANSAC_COMP		(1 << 0)
35 #define I2C_TRANSAC_START		(1 << 0)
36 #define I2C_RS_MUL_CNFG			(1 << 15)
37 #define I2C_RS_MUL_TRIG			(1 << 14)
38 #define I2C_DCM_DISABLE			0x0000
39 #define I2C_IO_CONFIG_OPEN_DRAIN	0x0003
40 #define I2C_IO_CONFIG_PUSH_PULL		0x0000
41 #define I2C_SOFT_RST			0x0001
42 #define I2C_HANDSHAKE_RST		0x0020
43 #define I2C_FIFO_ADDR_CLR		0x0001
44 #define I2C_DELAY_LEN			0x0002
45 #define I2C_ST_START_CON		0x8001
46 #define I2C_FS_START_CON		0x1800
47 #define I2C_TIME_CLR_VALUE		0x0000
48 #define I2C_TIME_DEFAULT_VALUE		0x0003
49 #define I2C_WRRD_TRANAC_VALUE		0x0002
50 #define I2C_RD_TRANAC_VALUE		0x0001
51 #define I2C_SCL_MIS_COMP_VALUE		0x0000
52 #define I2C_CHN_CLR_FLAG		0x0000
53 #define I2C_RELIABILITY		0x0010
54 #define I2C_DMAACK_ENABLE		0x0008
55 
56 #define I2C_DMA_CON_TX			0x0000
57 #define I2C_DMA_CON_RX			0x0001
58 #define I2C_DMA_ASYNC_MODE		0x0004
59 #define I2C_DMA_SKIP_CONFIG		0x0010
60 #define I2C_DMA_DIR_CHANGE		0x0200
61 #define I2C_DMA_START_EN		0x0001
62 #define I2C_DMA_INT_FLAG_NONE		0x0000
63 #define I2C_DMA_CLR_FLAG		0x0000
64 #define I2C_DMA_WARM_RST		0x0001
65 #define I2C_DMA_HARD_RST		0x0002
66 #define I2C_DMA_HANDSHAKE_RST		0x0004
67 
68 #define MAX_SAMPLE_CNT_DIV		8
69 #define MAX_STEP_CNT_DIV		64
70 #define MAX_CLOCK_DIV_8BITS		256
71 #define MAX_CLOCK_DIV_5BITS		32
72 #define MAX_HS_STEP_CNT_DIV		8
73 #define I2C_STANDARD_MODE_BUFFER	(1000 / 3)
74 #define I2C_FAST_MODE_BUFFER		(300 / 3)
75 #define I2C_FAST_MODE_PLUS_BUFFER	(20 / 3)
76 
77 #define I2C_CONTROL_RS                  (0x1 << 1)
78 #define I2C_CONTROL_DMA_EN              (0x1 << 2)
79 #define I2C_CONTROL_CLK_EXT_EN          (0x1 << 3)
80 #define I2C_CONTROL_DIR_CHANGE          (0x1 << 4)
81 #define I2C_CONTROL_ACKERR_DET_EN       (0x1 << 5)
82 #define I2C_CONTROL_TRANSFER_LEN_CHANGE (0x1 << 6)
83 #define I2C_CONTROL_DMAACK_EN           (0x1 << 8)
84 #define I2C_CONTROL_ASYNC_MODE          (0x1 << 9)
85 #define I2C_CONTROL_WRAPPER             (0x1 << 0)
86 
87 #define I2C_DRV_NAME		"i2c-mt65xx"
88 
89 /**
90  * enum i2c_mt65xx_clks - Clocks enumeration for MT65XX I2C
91  *
92  * @I2C_MT65XX_CLK_MAIN: main clock for i2c bus
93  * @I2C_MT65XX_CLK_DMA:  DMA clock for i2c via DMA
94  * @I2C_MT65XX_CLK_PMIC: PMIC clock for i2c from PMIC
95  * @I2C_MT65XX_CLK_ARB:  Arbitrator clock for i2c
96  * @I2C_MT65XX_CLK_MAX:  Number of supported clocks
97  */
98 enum i2c_mt65xx_clks {
99 	I2C_MT65XX_CLK_MAIN = 0,
100 	I2C_MT65XX_CLK_DMA,
101 	I2C_MT65XX_CLK_PMIC,
102 	I2C_MT65XX_CLK_ARB,
103 	I2C_MT65XX_CLK_MAX
104 };
105 
106 static const char * const i2c_mt65xx_clk_ids[I2C_MT65XX_CLK_MAX] = {
107 	"main", "dma", "pmic", "arb"
108 };
109 
110 enum DMA_REGS_OFFSET {
111 	OFFSET_INT_FLAG = 0x0,
112 	OFFSET_INT_EN = 0x04,
113 	OFFSET_EN = 0x08,
114 	OFFSET_RST = 0x0c,
115 	OFFSET_CON = 0x18,
116 	OFFSET_TX_MEM_ADDR = 0x1c,
117 	OFFSET_RX_MEM_ADDR = 0x20,
118 	OFFSET_TX_LEN = 0x24,
119 	OFFSET_RX_LEN = 0x28,
120 	OFFSET_TX_4G_MODE = 0x54,
121 	OFFSET_RX_4G_MODE = 0x58,
122 };
123 
124 enum i2c_trans_st_rs {
125 	I2C_TRANS_STOP = 0,
126 	I2C_TRANS_REPEATED_START,
127 };
128 
129 enum mtk_trans_op {
130 	I2C_MASTER_WR = 1,
131 	I2C_MASTER_RD,
132 	I2C_MASTER_WRRD,
133 };
134 
135 enum I2C_REGS_OFFSET {
136 	OFFSET_DATA_PORT,
137 	OFFSET_SLAVE_ADDR,
138 	OFFSET_INTR_MASK,
139 	OFFSET_INTR_STAT,
140 	OFFSET_CONTROL,
141 	OFFSET_TRANSFER_LEN,
142 	OFFSET_TRANSAC_LEN,
143 	OFFSET_DELAY_LEN,
144 	OFFSET_TIMING,
145 	OFFSET_START,
146 	OFFSET_EXT_CONF,
147 	OFFSET_FIFO_STAT,
148 	OFFSET_FIFO_THRESH,
149 	OFFSET_FIFO_ADDR_CLR,
150 	OFFSET_IO_CONFIG,
151 	OFFSET_RSV_DEBUG,
152 	OFFSET_HS,
153 	OFFSET_SOFTRESET,
154 	OFFSET_DCM_EN,
155 	OFFSET_MULTI_DMA,
156 	OFFSET_PATH_DIR,
157 	OFFSET_DEBUGSTAT,
158 	OFFSET_DEBUGCTRL,
159 	OFFSET_TRANSFER_LEN_AUX,
160 	OFFSET_CLOCK_DIV,
161 	OFFSET_LTIMING,
162 	OFFSET_SCL_HIGH_LOW_RATIO,
163 	OFFSET_HS_SCL_HIGH_LOW_RATIO,
164 	OFFSET_SCL_MIS_COMP_POINT,
165 	OFFSET_STA_STO_AC_TIMING,
166 	OFFSET_HS_STA_STO_AC_TIMING,
167 	OFFSET_SDA_TIMING,
168 };
169 
170 static const u16 mt_i2c_regs_v1[] = {
171 	[OFFSET_DATA_PORT] = 0x0,
172 	[OFFSET_SLAVE_ADDR] = 0x4,
173 	[OFFSET_INTR_MASK] = 0x8,
174 	[OFFSET_INTR_STAT] = 0xc,
175 	[OFFSET_CONTROL] = 0x10,
176 	[OFFSET_TRANSFER_LEN] = 0x14,
177 	[OFFSET_TRANSAC_LEN] = 0x18,
178 	[OFFSET_DELAY_LEN] = 0x1c,
179 	[OFFSET_TIMING] = 0x20,
180 	[OFFSET_START] = 0x24,
181 	[OFFSET_EXT_CONF] = 0x28,
182 	[OFFSET_FIFO_STAT] = 0x30,
183 	[OFFSET_FIFO_THRESH] = 0x34,
184 	[OFFSET_FIFO_ADDR_CLR] = 0x38,
185 	[OFFSET_IO_CONFIG] = 0x40,
186 	[OFFSET_RSV_DEBUG] = 0x44,
187 	[OFFSET_HS] = 0x48,
188 	[OFFSET_SOFTRESET] = 0x50,
189 	[OFFSET_DCM_EN] = 0x54,
190 	[OFFSET_PATH_DIR] = 0x60,
191 	[OFFSET_DEBUGSTAT] = 0x64,
192 	[OFFSET_DEBUGCTRL] = 0x68,
193 	[OFFSET_TRANSFER_LEN_AUX] = 0x6c,
194 	[OFFSET_CLOCK_DIV] = 0x70,
195 	[OFFSET_SCL_HIGH_LOW_RATIO] = 0x74,
196 	[OFFSET_HS_SCL_HIGH_LOW_RATIO] = 0x78,
197 	[OFFSET_SCL_MIS_COMP_POINT] = 0x7C,
198 	[OFFSET_STA_STO_AC_TIMING] = 0x80,
199 	[OFFSET_HS_STA_STO_AC_TIMING] = 0x84,
200 	[OFFSET_SDA_TIMING] = 0x88,
201 };
202 
203 static const u16 mt_i2c_regs_v2[] = {
204 	[OFFSET_DATA_PORT] = 0x0,
205 	[OFFSET_SLAVE_ADDR] = 0x4,
206 	[OFFSET_INTR_MASK] = 0x8,
207 	[OFFSET_INTR_STAT] = 0xc,
208 	[OFFSET_CONTROL] = 0x10,
209 	[OFFSET_TRANSFER_LEN] = 0x14,
210 	[OFFSET_TRANSAC_LEN] = 0x18,
211 	[OFFSET_DELAY_LEN] = 0x1c,
212 	[OFFSET_TIMING] = 0x20,
213 	[OFFSET_START] = 0x24,
214 	[OFFSET_EXT_CONF] = 0x28,
215 	[OFFSET_LTIMING] = 0x2c,
216 	[OFFSET_HS] = 0x30,
217 	[OFFSET_IO_CONFIG] = 0x34,
218 	[OFFSET_FIFO_ADDR_CLR] = 0x38,
219 	[OFFSET_SDA_TIMING] = 0x3c,
220 	[OFFSET_TRANSFER_LEN_AUX] = 0x44,
221 	[OFFSET_CLOCK_DIV] = 0x48,
222 	[OFFSET_SOFTRESET] = 0x50,
223 	[OFFSET_MULTI_DMA] = 0x8c,
224 	[OFFSET_SCL_MIS_COMP_POINT] = 0x90,
225 	[OFFSET_DEBUGSTAT] = 0xe4,
226 	[OFFSET_DEBUGCTRL] = 0xe8,
227 	[OFFSET_FIFO_STAT] = 0xf4,
228 	[OFFSET_FIFO_THRESH] = 0xf8,
229 	[OFFSET_DCM_EN] = 0xf88,
230 };
231 
232 struct mtk_i2c_compatible {
233 	const struct i2c_adapter_quirks *quirks;
234 	const u16 *regs;
235 	unsigned char pmic_i2c: 1;
236 	unsigned char dcm: 1;
237 	unsigned char auto_restart: 1;
238 	unsigned char aux_len_reg: 1;
239 	unsigned char timing_adjust: 1;
240 	unsigned char dma_sync: 1;
241 	unsigned char ltiming_adjust: 1;
242 	unsigned char apdma_sync: 1;
243 	unsigned char max_dma_support;
244 };
245 
246 struct mtk_i2c_ac_timing {
247 	u16 htiming;
248 	u16 ltiming;
249 	u16 hs;
250 	u16 ext;
251 	u16 inter_clk_div;
252 	u16 scl_hl_ratio;
253 	u16 hs_scl_hl_ratio;
254 	u16 sta_stop;
255 	u16 hs_sta_stop;
256 	u16 sda_timing;
257 };
258 
259 struct mtk_i2c {
260 	struct i2c_adapter adap;	/* i2c host adapter */
261 	struct device *dev;
262 	struct completion msg_complete;
263 	struct i2c_timings timing_info;
264 
265 	/* set in i2c probe */
266 	void __iomem *base;		/* i2c base addr */
267 	void __iomem *pdmabase;		/* dma base address*/
268 	struct clk_bulk_data clocks[I2C_MT65XX_CLK_MAX]; /* clocks for i2c */
269 	bool have_pmic;			/* can use i2c pins from PMIC */
270 	bool use_push_pull;		/* IO config push-pull mode */
271 
272 	u16 irq_stat;			/* interrupt status */
273 	unsigned int clk_src_div;
274 	unsigned int speed_hz;		/* The speed in transfer */
275 	enum mtk_trans_op op;
276 	u16 timing_reg;
277 	u16 high_speed_reg;
278 	u16 ltiming_reg;
279 	unsigned char auto_restart;
280 	bool ignore_restart_irq;
281 	struct mtk_i2c_ac_timing ac_timing;
282 	const struct mtk_i2c_compatible *dev_comp;
283 };
284 
285 /**
286  * struct i2c_spec_values:
287  * @min_low_ns: min LOW period of the SCL clock
288  * @min_su_sta_ns: min set-up time for a repeated START condition
289  * @max_hd_dat_ns: max data hold time
290  * @min_su_dat_ns: min data set-up time
291  */
292 struct i2c_spec_values {
293 	unsigned int min_low_ns;
294 	unsigned int min_su_sta_ns;
295 	unsigned int max_hd_dat_ns;
296 	unsigned int min_su_dat_ns;
297 };
298 
299 static const struct i2c_spec_values standard_mode_spec = {
300 	.min_low_ns = 4700 + I2C_STANDARD_MODE_BUFFER,
301 	.min_su_sta_ns = 4700 + I2C_STANDARD_MODE_BUFFER,
302 	.max_hd_dat_ns = 3450 - I2C_STANDARD_MODE_BUFFER,
303 	.min_su_dat_ns = 250 + I2C_STANDARD_MODE_BUFFER,
304 };
305 
306 static const struct i2c_spec_values fast_mode_spec = {
307 	.min_low_ns = 1300 + I2C_FAST_MODE_BUFFER,
308 	.min_su_sta_ns = 600 + I2C_FAST_MODE_BUFFER,
309 	.max_hd_dat_ns = 900 - I2C_FAST_MODE_BUFFER,
310 	.min_su_dat_ns = 100 + I2C_FAST_MODE_BUFFER,
311 };
312 
313 static const struct i2c_spec_values fast_mode_plus_spec = {
314 	.min_low_ns = 500 + I2C_FAST_MODE_PLUS_BUFFER,
315 	.min_su_sta_ns = 260 + I2C_FAST_MODE_PLUS_BUFFER,
316 	.max_hd_dat_ns = 400 - I2C_FAST_MODE_PLUS_BUFFER,
317 	.min_su_dat_ns = 50 + I2C_FAST_MODE_PLUS_BUFFER,
318 };
319 
320 static const struct i2c_adapter_quirks mt6577_i2c_quirks = {
321 	.flags = I2C_AQ_COMB_WRITE_THEN_READ,
322 	.max_num_msgs = 1,
323 	.max_write_len = 255,
324 	.max_read_len = 255,
325 	.max_comb_1st_msg_len = 255,
326 	.max_comb_2nd_msg_len = 31,
327 };
328 
329 static const struct i2c_adapter_quirks mt7622_i2c_quirks = {
330 	.max_num_msgs = 255,
331 };
332 
333 static const struct i2c_adapter_quirks mt8183_i2c_quirks = {
334 	.flags = I2C_AQ_NO_ZERO_LEN,
335 };
336 
337 static const struct mtk_i2c_compatible mt2712_compat = {
338 	.regs = mt_i2c_regs_v1,
339 	.pmic_i2c = 0,
340 	.dcm = 1,
341 	.auto_restart = 1,
342 	.aux_len_reg = 1,
343 	.timing_adjust = 1,
344 	.dma_sync = 0,
345 	.ltiming_adjust = 0,
346 	.apdma_sync = 0,
347 	.max_dma_support = 33,
348 };
349 
350 static const struct mtk_i2c_compatible mt6577_compat = {
351 	.quirks = &mt6577_i2c_quirks,
352 	.regs = mt_i2c_regs_v1,
353 	.pmic_i2c = 0,
354 	.dcm = 1,
355 	.auto_restart = 0,
356 	.aux_len_reg = 0,
357 	.timing_adjust = 0,
358 	.dma_sync = 0,
359 	.ltiming_adjust = 0,
360 	.apdma_sync = 0,
361 	.max_dma_support = 32,
362 };
363 
364 static const struct mtk_i2c_compatible mt6589_compat = {
365 	.quirks = &mt6577_i2c_quirks,
366 	.regs = mt_i2c_regs_v1,
367 	.pmic_i2c = 1,
368 	.dcm = 0,
369 	.auto_restart = 0,
370 	.aux_len_reg = 0,
371 	.timing_adjust = 0,
372 	.dma_sync = 0,
373 	.ltiming_adjust = 0,
374 	.apdma_sync = 0,
375 	.max_dma_support = 32,
376 };
377 
378 static const struct mtk_i2c_compatible mt7622_compat = {
379 	.quirks = &mt7622_i2c_quirks,
380 	.regs = mt_i2c_regs_v1,
381 	.pmic_i2c = 0,
382 	.dcm = 1,
383 	.auto_restart = 1,
384 	.aux_len_reg = 1,
385 	.timing_adjust = 0,
386 	.dma_sync = 0,
387 	.ltiming_adjust = 0,
388 	.apdma_sync = 0,
389 	.max_dma_support = 32,
390 };
391 
392 static const struct mtk_i2c_compatible mt8168_compat = {
393 	.regs = mt_i2c_regs_v1,
394 	.pmic_i2c = 0,
395 	.dcm = 1,
396 	.auto_restart = 1,
397 	.aux_len_reg = 1,
398 	.timing_adjust = 1,
399 	.dma_sync = 1,
400 	.ltiming_adjust = 0,
401 	.apdma_sync = 0,
402 	.max_dma_support = 33,
403 };
404 
405 static const struct mtk_i2c_compatible mt8173_compat = {
406 	.regs = mt_i2c_regs_v1,
407 	.pmic_i2c = 0,
408 	.dcm = 1,
409 	.auto_restart = 1,
410 	.aux_len_reg = 1,
411 	.timing_adjust = 0,
412 	.dma_sync = 0,
413 	.ltiming_adjust = 0,
414 	.apdma_sync = 0,
415 	.max_dma_support = 33,
416 };
417 
418 static const struct mtk_i2c_compatible mt8183_compat = {
419 	.quirks = &mt8183_i2c_quirks,
420 	.regs = mt_i2c_regs_v2,
421 	.pmic_i2c = 0,
422 	.dcm = 0,
423 	.auto_restart = 1,
424 	.aux_len_reg = 1,
425 	.timing_adjust = 1,
426 	.dma_sync = 1,
427 	.ltiming_adjust = 1,
428 	.apdma_sync = 0,
429 	.max_dma_support = 33,
430 };
431 
432 static const struct mtk_i2c_compatible mt8186_compat = {
433 	.regs = mt_i2c_regs_v2,
434 	.pmic_i2c = 0,
435 	.dcm = 0,
436 	.auto_restart = 1,
437 	.aux_len_reg = 1,
438 	.timing_adjust = 1,
439 	.dma_sync = 0,
440 	.ltiming_adjust = 1,
441 	.apdma_sync = 0,
442 	.max_dma_support = 36,
443 };
444 
445 static const struct mtk_i2c_compatible mt8192_compat = {
446 	.quirks = &mt8183_i2c_quirks,
447 	.regs = mt_i2c_regs_v2,
448 	.pmic_i2c = 0,
449 	.dcm = 0,
450 	.auto_restart = 1,
451 	.aux_len_reg = 1,
452 	.timing_adjust = 1,
453 	.dma_sync = 1,
454 	.ltiming_adjust = 1,
455 	.apdma_sync = 1,
456 	.max_dma_support = 36,
457 };
458 
459 static const struct of_device_id mtk_i2c_of_match[] = {
460 	{ .compatible = "mediatek,mt2712-i2c", .data = &mt2712_compat },
461 	{ .compatible = "mediatek,mt6577-i2c", .data = &mt6577_compat },
462 	{ .compatible = "mediatek,mt6589-i2c", .data = &mt6589_compat },
463 	{ .compatible = "mediatek,mt7622-i2c", .data = &mt7622_compat },
464 	{ .compatible = "mediatek,mt8168-i2c", .data = &mt8168_compat },
465 	{ .compatible = "mediatek,mt8173-i2c", .data = &mt8173_compat },
466 	{ .compatible = "mediatek,mt8183-i2c", .data = &mt8183_compat },
467 	{ .compatible = "mediatek,mt8186-i2c", .data = &mt8186_compat },
468 	{ .compatible = "mediatek,mt8192-i2c", .data = &mt8192_compat },
469 	{}
470 };
471 MODULE_DEVICE_TABLE(of, mtk_i2c_of_match);
472 
473 static u16 mtk_i2c_readw(struct mtk_i2c *i2c, enum I2C_REGS_OFFSET reg)
474 {
475 	return readw(i2c->base + i2c->dev_comp->regs[reg]);
476 }
477 
478 static void mtk_i2c_writew(struct mtk_i2c *i2c, u16 val,
479 			   enum I2C_REGS_OFFSET reg)
480 {
481 	writew(val, i2c->base + i2c->dev_comp->regs[reg]);
482 }
483 
484 static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
485 {
486 	u16 control_reg;
487 	u16 intr_stat_reg;
488 	u16 ext_conf_val;
489 
490 	mtk_i2c_writew(i2c, I2C_CHN_CLR_FLAG, OFFSET_START);
491 	intr_stat_reg = mtk_i2c_readw(i2c, OFFSET_INTR_STAT);
492 	mtk_i2c_writew(i2c, intr_stat_reg, OFFSET_INTR_STAT);
493 
494 	if (i2c->dev_comp->apdma_sync) {
495 		writel(I2C_DMA_WARM_RST, i2c->pdmabase + OFFSET_RST);
496 		udelay(10);
497 		writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
498 		udelay(10);
499 		writel(I2C_DMA_HANDSHAKE_RST | I2C_DMA_HARD_RST,
500 		       i2c->pdmabase + OFFSET_RST);
501 		mtk_i2c_writew(i2c, I2C_HANDSHAKE_RST | I2C_SOFT_RST,
502 			       OFFSET_SOFTRESET);
503 		udelay(10);
504 		writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
505 		mtk_i2c_writew(i2c, I2C_CHN_CLR_FLAG, OFFSET_SOFTRESET);
506 	} else {
507 		writel(I2C_DMA_HARD_RST, i2c->pdmabase + OFFSET_RST);
508 		udelay(50);
509 		writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
510 		mtk_i2c_writew(i2c, I2C_SOFT_RST, OFFSET_SOFTRESET);
511 	}
512 
513 	/* Set ioconfig */
514 	if (i2c->use_push_pull)
515 		mtk_i2c_writew(i2c, I2C_IO_CONFIG_PUSH_PULL, OFFSET_IO_CONFIG);
516 	else
517 		mtk_i2c_writew(i2c, I2C_IO_CONFIG_OPEN_DRAIN, OFFSET_IO_CONFIG);
518 
519 	if (i2c->dev_comp->dcm)
520 		mtk_i2c_writew(i2c, I2C_DCM_DISABLE, OFFSET_DCM_EN);
521 
522 	mtk_i2c_writew(i2c, i2c->timing_reg, OFFSET_TIMING);
523 	mtk_i2c_writew(i2c, i2c->high_speed_reg, OFFSET_HS);
524 	if (i2c->dev_comp->ltiming_adjust)
525 		mtk_i2c_writew(i2c, i2c->ltiming_reg, OFFSET_LTIMING);
526 
527 	if (i2c->speed_hz <= I2C_MAX_STANDARD_MODE_FREQ)
528 		ext_conf_val = I2C_ST_START_CON;
529 	else
530 		ext_conf_val = I2C_FS_START_CON;
531 
532 	if (i2c->dev_comp->timing_adjust) {
533 		ext_conf_val = i2c->ac_timing.ext;
534 		mtk_i2c_writew(i2c, i2c->ac_timing.inter_clk_div,
535 			       OFFSET_CLOCK_DIV);
536 		mtk_i2c_writew(i2c, I2C_SCL_MIS_COMP_VALUE,
537 			       OFFSET_SCL_MIS_COMP_POINT);
538 		mtk_i2c_writew(i2c, i2c->ac_timing.sda_timing,
539 			       OFFSET_SDA_TIMING);
540 
541 		if (i2c->dev_comp->ltiming_adjust) {
542 			mtk_i2c_writew(i2c, i2c->ac_timing.htiming,
543 				       OFFSET_TIMING);
544 			mtk_i2c_writew(i2c, i2c->ac_timing.hs, OFFSET_HS);
545 			mtk_i2c_writew(i2c, i2c->ac_timing.ltiming,
546 				       OFFSET_LTIMING);
547 		} else {
548 			mtk_i2c_writew(i2c, i2c->ac_timing.scl_hl_ratio,
549 				       OFFSET_SCL_HIGH_LOW_RATIO);
550 			mtk_i2c_writew(i2c, i2c->ac_timing.hs_scl_hl_ratio,
551 				       OFFSET_HS_SCL_HIGH_LOW_RATIO);
552 			mtk_i2c_writew(i2c, i2c->ac_timing.sta_stop,
553 				       OFFSET_STA_STO_AC_TIMING);
554 			mtk_i2c_writew(i2c, i2c->ac_timing.hs_sta_stop,
555 				       OFFSET_HS_STA_STO_AC_TIMING);
556 		}
557 	}
558 	mtk_i2c_writew(i2c, ext_conf_val, OFFSET_EXT_CONF);
559 
560 	/* If use i2c pin from PMIC mt6397 side, need set PATH_DIR first */
561 	if (i2c->have_pmic)
562 		mtk_i2c_writew(i2c, I2C_CONTROL_WRAPPER, OFFSET_PATH_DIR);
563 
564 	control_reg = I2C_CONTROL_ACKERR_DET_EN |
565 		      I2C_CONTROL_CLK_EXT_EN | I2C_CONTROL_DMA_EN;
566 	if (i2c->dev_comp->dma_sync)
567 		control_reg |= I2C_CONTROL_DMAACK_EN | I2C_CONTROL_ASYNC_MODE;
568 
569 	mtk_i2c_writew(i2c, control_reg, OFFSET_CONTROL);
570 	mtk_i2c_writew(i2c, I2C_DELAY_LEN, OFFSET_DELAY_LEN);
571 }
572 
573 static const struct i2c_spec_values *mtk_i2c_get_spec(unsigned int speed)
574 {
575 	if (speed <= I2C_MAX_STANDARD_MODE_FREQ)
576 		return &standard_mode_spec;
577 	else if (speed <= I2C_MAX_FAST_MODE_FREQ)
578 		return &fast_mode_spec;
579 	else
580 		return &fast_mode_plus_spec;
581 }
582 
583 static int mtk_i2c_max_step_cnt(unsigned int target_speed)
584 {
585 	if (target_speed > I2C_MAX_FAST_MODE_PLUS_FREQ)
586 		return MAX_HS_STEP_CNT_DIV;
587 	else
588 		return MAX_STEP_CNT_DIV;
589 }
590 
591 static int mtk_i2c_get_clk_div_restri(struct mtk_i2c *i2c,
592 				      unsigned int sample_cnt)
593 {
594 	int clk_div_restri = 0;
595 
596 	if (i2c->dev_comp->ltiming_adjust == 0)
597 		return 0;
598 
599 	if (sample_cnt == 1) {
600 		if (i2c->ac_timing.inter_clk_div == 0)
601 			clk_div_restri = 0;
602 		else
603 			clk_div_restri = 1;
604 	} else {
605 		if (i2c->ac_timing.inter_clk_div == 0)
606 			clk_div_restri = -1;
607 		else if (i2c->ac_timing.inter_clk_div == 1)
608 			clk_div_restri = 0;
609 		else
610 			clk_div_restri = 1;
611 	}
612 
613 	return clk_div_restri;
614 }
615 
616 /*
617  * Check and Calculate i2c ac-timing
618  *
619  * Hardware design:
620  * sample_ns = (1000000000 * (sample_cnt + 1)) / clk_src
621  * xxx_cnt_div =  spec->min_xxx_ns / sample_ns
622  *
623  * Sample_ns is rounded down for xxx_cnt_div would be greater
624  * than the smallest spec.
625  * The sda_timing is chosen as the middle value between
626  * the largest and smallest.
627  */
628 static int mtk_i2c_check_ac_timing(struct mtk_i2c *i2c,
629 				   unsigned int clk_src,
630 				   unsigned int check_speed,
631 				   unsigned int step_cnt,
632 				   unsigned int sample_cnt)
633 {
634 	const struct i2c_spec_values *spec;
635 	unsigned int su_sta_cnt, low_cnt, high_cnt, max_step_cnt;
636 	unsigned int sda_max, sda_min, clk_ns, max_sta_cnt = 0x3f;
637 	unsigned int sample_ns = div_u64(1000000000ULL * (sample_cnt + 1),
638 					 clk_src);
639 
640 	if (!i2c->dev_comp->timing_adjust)
641 		return 0;
642 
643 	if (i2c->dev_comp->ltiming_adjust)
644 		max_sta_cnt = 0x100;
645 
646 	spec = mtk_i2c_get_spec(check_speed);
647 
648 	if (i2c->dev_comp->ltiming_adjust)
649 		clk_ns = 1000000000 / clk_src;
650 	else
651 		clk_ns = sample_ns / 2;
652 
653 	su_sta_cnt = DIV_ROUND_UP(spec->min_su_sta_ns +
654 				  i2c->timing_info.scl_int_delay_ns, clk_ns);
655 	if (su_sta_cnt > max_sta_cnt)
656 		return -1;
657 
658 	low_cnt = DIV_ROUND_UP(spec->min_low_ns, sample_ns);
659 	max_step_cnt = mtk_i2c_max_step_cnt(check_speed);
660 	if ((2 * step_cnt) > low_cnt && low_cnt < max_step_cnt) {
661 		if (low_cnt > step_cnt) {
662 			high_cnt = 2 * step_cnt - low_cnt;
663 		} else {
664 			high_cnt = step_cnt;
665 			low_cnt = step_cnt;
666 		}
667 	} else {
668 		return -2;
669 	}
670 
671 	sda_max = spec->max_hd_dat_ns / sample_ns;
672 	if (sda_max > low_cnt)
673 		sda_max = 0;
674 
675 	sda_min = DIV_ROUND_UP(spec->min_su_dat_ns, sample_ns);
676 	if (sda_min < low_cnt)
677 		sda_min = 0;
678 
679 	if (sda_min > sda_max)
680 		return -3;
681 
682 	if (check_speed > I2C_MAX_FAST_MODE_PLUS_FREQ) {
683 		if (i2c->dev_comp->ltiming_adjust) {
684 			i2c->ac_timing.hs = I2C_TIME_DEFAULT_VALUE |
685 				(sample_cnt << 12) | (high_cnt << 8);
686 			i2c->ac_timing.ltiming &= ~GENMASK(15, 9);
687 			i2c->ac_timing.ltiming |= (sample_cnt << 12) |
688 				(low_cnt << 9);
689 			i2c->ac_timing.ext &= ~GENMASK(7, 1);
690 			i2c->ac_timing.ext |= (su_sta_cnt << 1) | (1 << 0);
691 		} else {
692 			i2c->ac_timing.hs_scl_hl_ratio = (1 << 12) |
693 				(high_cnt << 6) | low_cnt;
694 			i2c->ac_timing.hs_sta_stop = (su_sta_cnt << 8) |
695 				su_sta_cnt;
696 		}
697 		i2c->ac_timing.sda_timing &= ~GENMASK(11, 6);
698 		i2c->ac_timing.sda_timing |= (1 << 12) |
699 			((sda_max + sda_min) / 2) << 6;
700 	} else {
701 		if (i2c->dev_comp->ltiming_adjust) {
702 			i2c->ac_timing.htiming = (sample_cnt << 8) | (high_cnt);
703 			i2c->ac_timing.ltiming = (sample_cnt << 6) | (low_cnt);
704 			i2c->ac_timing.ext = (su_sta_cnt << 8) | (1 << 0);
705 		} else {
706 			i2c->ac_timing.scl_hl_ratio = (1 << 12) |
707 				(high_cnt << 6) | low_cnt;
708 			i2c->ac_timing.sta_stop = (su_sta_cnt << 8) |
709 				su_sta_cnt;
710 		}
711 
712 		i2c->ac_timing.sda_timing = (1 << 12) |
713 			(sda_max + sda_min) / 2;
714 	}
715 
716 	return 0;
717 }
718 
719 /*
720  * Calculate i2c port speed
721  *
722  * Hardware design:
723  * i2c_bus_freq = parent_clk / (clock_div * 2 * sample_cnt * step_cnt)
724  * clock_div: fixed in hardware, but may be various in different SoCs
725  *
726  * The calculation want to pick the highest bus frequency that is still
727  * less than or equal to i2c->speed_hz. The calculation try to get
728  * sample_cnt and step_cn
729  */
730 static int mtk_i2c_calculate_speed(struct mtk_i2c *i2c, unsigned int clk_src,
731 				   unsigned int target_speed,
732 				   unsigned int *timing_step_cnt,
733 				   unsigned int *timing_sample_cnt)
734 {
735 	unsigned int step_cnt;
736 	unsigned int sample_cnt;
737 	unsigned int max_step_cnt;
738 	unsigned int base_sample_cnt = MAX_SAMPLE_CNT_DIV;
739 	unsigned int base_step_cnt;
740 	unsigned int opt_div;
741 	unsigned int best_mul;
742 	unsigned int cnt_mul;
743 	int ret = -EINVAL;
744 	int clk_div_restri = 0;
745 
746 	if (target_speed > I2C_MAX_HIGH_SPEED_MODE_FREQ)
747 		target_speed = I2C_MAX_HIGH_SPEED_MODE_FREQ;
748 
749 	max_step_cnt = mtk_i2c_max_step_cnt(target_speed);
750 	base_step_cnt = max_step_cnt;
751 	/* Find the best combination */
752 	opt_div = DIV_ROUND_UP(clk_src >> 1, target_speed);
753 	best_mul = MAX_SAMPLE_CNT_DIV * max_step_cnt;
754 
755 	/* Search for the best pair (sample_cnt, step_cnt) with
756 	 * 0 < sample_cnt < MAX_SAMPLE_CNT_DIV
757 	 * 0 < step_cnt < max_step_cnt
758 	 * sample_cnt * step_cnt >= opt_div
759 	 * optimizing for sample_cnt * step_cnt being minimal
760 	 */
761 	for (sample_cnt = 1; sample_cnt <= MAX_SAMPLE_CNT_DIV; sample_cnt++) {
762 		clk_div_restri = mtk_i2c_get_clk_div_restri(i2c, sample_cnt);
763 		step_cnt = DIV_ROUND_UP(opt_div + clk_div_restri, sample_cnt);
764 		cnt_mul = step_cnt * sample_cnt;
765 		if (step_cnt > max_step_cnt)
766 			continue;
767 
768 		if (cnt_mul < best_mul) {
769 			ret = mtk_i2c_check_ac_timing(i2c, clk_src,
770 				target_speed, step_cnt - 1, sample_cnt - 1);
771 			if (ret)
772 				continue;
773 
774 			best_mul = cnt_mul;
775 			base_sample_cnt = sample_cnt;
776 			base_step_cnt = step_cnt;
777 			if (best_mul == (opt_div + clk_div_restri))
778 				break;
779 		}
780 	}
781 
782 	if (ret)
783 		return -EINVAL;
784 
785 	sample_cnt = base_sample_cnt;
786 	step_cnt = base_step_cnt;
787 
788 	if ((clk_src / (2 * (sample_cnt * step_cnt - clk_div_restri))) >
789 		target_speed) {
790 		/* In this case, hardware can't support such
791 		 * low i2c_bus_freq
792 		 */
793 		dev_dbg(i2c->dev, "Unsupported speed (%uhz)\n",	target_speed);
794 		return -EINVAL;
795 	}
796 
797 	*timing_step_cnt = step_cnt - 1;
798 	*timing_sample_cnt = sample_cnt - 1;
799 
800 	return 0;
801 }
802 
803 static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk)
804 {
805 	unsigned int clk_src;
806 	unsigned int step_cnt;
807 	unsigned int sample_cnt;
808 	unsigned int l_step_cnt;
809 	unsigned int l_sample_cnt;
810 	unsigned int target_speed;
811 	unsigned int clk_div;
812 	unsigned int max_clk_div;
813 	int ret;
814 
815 	target_speed = i2c->speed_hz;
816 	parent_clk /= i2c->clk_src_div;
817 
818 	if (i2c->dev_comp->timing_adjust && i2c->dev_comp->ltiming_adjust)
819 		max_clk_div = MAX_CLOCK_DIV_5BITS;
820 	else if (i2c->dev_comp->timing_adjust)
821 		max_clk_div = MAX_CLOCK_DIV_8BITS;
822 	else
823 		max_clk_div = 1;
824 
825 	for (clk_div = 1; clk_div <= max_clk_div; clk_div++) {
826 		clk_src = parent_clk / clk_div;
827 		i2c->ac_timing.inter_clk_div = clk_div - 1;
828 
829 		if (target_speed > I2C_MAX_FAST_MODE_PLUS_FREQ) {
830 			/* Set master code speed register */
831 			ret = mtk_i2c_calculate_speed(i2c, clk_src,
832 						      I2C_MAX_FAST_MODE_FREQ,
833 						      &l_step_cnt,
834 						      &l_sample_cnt);
835 			if (ret < 0)
836 				continue;
837 
838 			i2c->timing_reg = (l_sample_cnt << 8) | l_step_cnt;
839 
840 			/* Set the high speed mode register */
841 			ret = mtk_i2c_calculate_speed(i2c, clk_src,
842 						      target_speed, &step_cnt,
843 						      &sample_cnt);
844 			if (ret < 0)
845 				continue;
846 
847 			i2c->high_speed_reg = I2C_TIME_DEFAULT_VALUE |
848 					(sample_cnt << 12) | (step_cnt << 8);
849 
850 			if (i2c->dev_comp->ltiming_adjust)
851 				i2c->ltiming_reg =
852 					(l_sample_cnt << 6) | l_step_cnt |
853 					(sample_cnt << 12) | (step_cnt << 9);
854 		} else {
855 			ret = mtk_i2c_calculate_speed(i2c, clk_src,
856 						      target_speed, &l_step_cnt,
857 						      &l_sample_cnt);
858 			if (ret < 0)
859 				continue;
860 
861 			i2c->timing_reg = (l_sample_cnt << 8) | l_step_cnt;
862 
863 			/* Disable the high speed transaction */
864 			i2c->high_speed_reg = I2C_TIME_CLR_VALUE;
865 
866 			if (i2c->dev_comp->ltiming_adjust)
867 				i2c->ltiming_reg =
868 					(l_sample_cnt << 6) | l_step_cnt;
869 		}
870 
871 		break;
872 	}
873 
874 
875 	return 0;
876 }
877 
878 static void i2c_dump_register(struct mtk_i2c *i2c)
879 {
880 	dev_dbg(i2c->dev, "SLAVE_ADDR: 0x%x, INTR_MASK: 0x%x\n",
881 		mtk_i2c_readw(i2c, OFFSET_SLAVE_ADDR),
882 		mtk_i2c_readw(i2c, OFFSET_INTR_MASK));
883 	dev_dbg(i2c->dev, "INTR_STAT: 0x%x, CONTROL: 0x%x\n",
884 		mtk_i2c_readw(i2c, OFFSET_INTR_STAT),
885 		mtk_i2c_readw(i2c, OFFSET_CONTROL));
886 	dev_dbg(i2c->dev, "TRANSFER_LEN: 0x%x, TRANSAC_LEN: 0x%x\n",
887 		mtk_i2c_readw(i2c, OFFSET_TRANSFER_LEN),
888 		mtk_i2c_readw(i2c, OFFSET_TRANSAC_LEN));
889 	dev_dbg(i2c->dev, "DELAY_LEN: 0x%x, HTIMING: 0x%x\n",
890 		mtk_i2c_readw(i2c, OFFSET_DELAY_LEN),
891 		mtk_i2c_readw(i2c, OFFSET_TIMING));
892 	dev_dbg(i2c->dev, "START: 0x%x, EXT_CONF: 0x%x\n",
893 		mtk_i2c_readw(i2c, OFFSET_START),
894 		mtk_i2c_readw(i2c, OFFSET_EXT_CONF));
895 	dev_dbg(i2c->dev, "HS: 0x%x, IO_CONFIG: 0x%x\n",
896 		mtk_i2c_readw(i2c, OFFSET_HS),
897 		mtk_i2c_readw(i2c, OFFSET_IO_CONFIG));
898 	dev_dbg(i2c->dev, "DCM_EN: 0x%x, TRANSFER_LEN_AUX: 0x%x\n",
899 		mtk_i2c_readw(i2c, OFFSET_DCM_EN),
900 		mtk_i2c_readw(i2c, OFFSET_TRANSFER_LEN_AUX));
901 	dev_dbg(i2c->dev, "CLOCK_DIV: 0x%x, FIFO_STAT: 0x%x\n",
902 		mtk_i2c_readw(i2c, OFFSET_CLOCK_DIV),
903 		mtk_i2c_readw(i2c, OFFSET_FIFO_STAT));
904 	dev_dbg(i2c->dev, "DEBUGCTRL : 0x%x, DEBUGSTAT: 0x%x\n",
905 		mtk_i2c_readw(i2c, OFFSET_DEBUGCTRL),
906 		mtk_i2c_readw(i2c, OFFSET_DEBUGSTAT));
907 	if (i2c->dev_comp->regs == mt_i2c_regs_v2) {
908 		dev_dbg(i2c->dev, "LTIMING: 0x%x, MULTI_DMA: 0x%x\n",
909 			mtk_i2c_readw(i2c, OFFSET_LTIMING),
910 			mtk_i2c_readw(i2c, OFFSET_MULTI_DMA));
911 	}
912 	dev_dbg(i2c->dev, "\nDMA_INT_FLAG: 0x%x, DMA_INT_EN: 0x%x\n",
913 		readl(i2c->pdmabase + OFFSET_INT_FLAG),
914 		readl(i2c->pdmabase + OFFSET_INT_EN));
915 	dev_dbg(i2c->dev, "DMA_EN: 0x%x, DMA_CON: 0x%x\n",
916 		readl(i2c->pdmabase + OFFSET_EN),
917 		readl(i2c->pdmabase + OFFSET_CON));
918 	dev_dbg(i2c->dev, "DMA_TX_MEM_ADDR: 0x%x, DMA_RX_MEM_ADDR: 0x%x\n",
919 		readl(i2c->pdmabase + OFFSET_TX_MEM_ADDR),
920 		readl(i2c->pdmabase + OFFSET_RX_MEM_ADDR));
921 	dev_dbg(i2c->dev, "DMA_TX_LEN: 0x%x, DMA_RX_LEN: 0x%x\n",
922 		readl(i2c->pdmabase + OFFSET_TX_LEN),
923 		readl(i2c->pdmabase + OFFSET_RX_LEN));
924 	dev_dbg(i2c->dev, "DMA_TX_4G_MODE: 0x%x, DMA_RX_4G_MODE: 0x%x",
925 		readl(i2c->pdmabase + OFFSET_TX_4G_MODE),
926 		readl(i2c->pdmabase + OFFSET_RX_4G_MODE));
927 }
928 
929 static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
930 			       int num, int left_num)
931 {
932 	u16 addr_reg;
933 	u16 start_reg;
934 	u16 control_reg;
935 	u16 restart_flag = 0;
936 	u16 dma_sync = 0;
937 	u32 reg_4g_mode;
938 	u32 reg_dma_reset;
939 	u8 *dma_rd_buf = NULL;
940 	u8 *dma_wr_buf = NULL;
941 	dma_addr_t rpaddr = 0;
942 	dma_addr_t wpaddr = 0;
943 	int ret;
944 
945 	i2c->irq_stat = 0;
946 
947 	if (i2c->auto_restart)
948 		restart_flag = I2C_RS_TRANSFER;
949 
950 	reinit_completion(&i2c->msg_complete);
951 
952 	if (i2c->dev_comp->apdma_sync &&
953 	    i2c->op != I2C_MASTER_WRRD && num > 1) {
954 		mtk_i2c_writew(i2c, 0x00, OFFSET_DEBUGCTRL);
955 		writel(I2C_DMA_HANDSHAKE_RST | I2C_DMA_WARM_RST,
956 		       i2c->pdmabase + OFFSET_RST);
957 
958 		ret = readw_poll_timeout(i2c->pdmabase + OFFSET_RST,
959 					 reg_dma_reset,
960 					 !(reg_dma_reset & I2C_DMA_WARM_RST),
961 					 0, 100);
962 		if (ret) {
963 			dev_err(i2c->dev, "DMA warm reset timeout\n");
964 			return -ETIMEDOUT;
965 		}
966 
967 		writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
968 		mtk_i2c_writew(i2c, I2C_HANDSHAKE_RST, OFFSET_SOFTRESET);
969 		mtk_i2c_writew(i2c, I2C_CHN_CLR_FLAG, OFFSET_SOFTRESET);
970 		mtk_i2c_writew(i2c, I2C_RELIABILITY | I2C_DMAACK_ENABLE,
971 			       OFFSET_DEBUGCTRL);
972 	}
973 
974 	control_reg = mtk_i2c_readw(i2c, OFFSET_CONTROL) &
975 			~(I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS);
976 	if ((i2c->speed_hz > I2C_MAX_FAST_MODE_PLUS_FREQ) || (left_num >= 1))
977 		control_reg |= I2C_CONTROL_RS;
978 
979 	if (i2c->op == I2C_MASTER_WRRD)
980 		control_reg |= I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS;
981 
982 	mtk_i2c_writew(i2c, control_reg, OFFSET_CONTROL);
983 
984 	addr_reg = i2c_8bit_addr_from_msg(msgs);
985 	mtk_i2c_writew(i2c, addr_reg, OFFSET_SLAVE_ADDR);
986 
987 	/* Clear interrupt status */
988 	mtk_i2c_writew(i2c, restart_flag | I2C_HS_NACKERR | I2C_ACKERR |
989 			    I2C_ARB_LOST | I2C_TRANSAC_COMP, OFFSET_INTR_STAT);
990 
991 	mtk_i2c_writew(i2c, I2C_FIFO_ADDR_CLR, OFFSET_FIFO_ADDR_CLR);
992 
993 	/* Enable interrupt */
994 	mtk_i2c_writew(i2c, restart_flag | I2C_HS_NACKERR | I2C_ACKERR |
995 			    I2C_ARB_LOST | I2C_TRANSAC_COMP, OFFSET_INTR_MASK);
996 
997 	/* Set transfer and transaction len */
998 	if (i2c->op == I2C_MASTER_WRRD) {
999 		if (i2c->dev_comp->aux_len_reg) {
1000 			mtk_i2c_writew(i2c, msgs->len, OFFSET_TRANSFER_LEN);
1001 			mtk_i2c_writew(i2c, (msgs + 1)->len,
1002 					    OFFSET_TRANSFER_LEN_AUX);
1003 		} else {
1004 			mtk_i2c_writew(i2c, msgs->len | ((msgs + 1)->len) << 8,
1005 					    OFFSET_TRANSFER_LEN);
1006 		}
1007 		mtk_i2c_writew(i2c, I2C_WRRD_TRANAC_VALUE, OFFSET_TRANSAC_LEN);
1008 	} else {
1009 		mtk_i2c_writew(i2c, msgs->len, OFFSET_TRANSFER_LEN);
1010 		mtk_i2c_writew(i2c, num, OFFSET_TRANSAC_LEN);
1011 	}
1012 
1013 	if (i2c->dev_comp->apdma_sync) {
1014 		dma_sync = I2C_DMA_SKIP_CONFIG | I2C_DMA_ASYNC_MODE;
1015 		if (i2c->op == I2C_MASTER_WRRD)
1016 			dma_sync |= I2C_DMA_DIR_CHANGE;
1017 	}
1018 
1019 	/* Prepare buffer data to start transfer */
1020 	if (i2c->op == I2C_MASTER_RD) {
1021 		writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG);
1022 		writel(I2C_DMA_CON_RX | dma_sync, i2c->pdmabase + OFFSET_CON);
1023 
1024 		dma_rd_buf = i2c_get_dma_safe_msg_buf(msgs, 1);
1025 		if (!dma_rd_buf)
1026 			return -ENOMEM;
1027 
1028 		rpaddr = dma_map_single(i2c->dev, dma_rd_buf,
1029 					msgs->len, DMA_FROM_DEVICE);
1030 		if (dma_mapping_error(i2c->dev, rpaddr)) {
1031 			i2c_put_dma_safe_msg_buf(dma_rd_buf, msgs, false);
1032 
1033 			return -ENOMEM;
1034 		}
1035 
1036 		if (i2c->dev_comp->max_dma_support > 32) {
1037 			reg_4g_mode = upper_32_bits(rpaddr);
1038 			writel(reg_4g_mode, i2c->pdmabase + OFFSET_RX_4G_MODE);
1039 		}
1040 
1041 		writel((u32)rpaddr, i2c->pdmabase + OFFSET_RX_MEM_ADDR);
1042 		writel(msgs->len, i2c->pdmabase + OFFSET_RX_LEN);
1043 	} else if (i2c->op == I2C_MASTER_WR) {
1044 		writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG);
1045 		writel(I2C_DMA_CON_TX | dma_sync, i2c->pdmabase + OFFSET_CON);
1046 
1047 		dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 1);
1048 		if (!dma_wr_buf)
1049 			return -ENOMEM;
1050 
1051 		wpaddr = dma_map_single(i2c->dev, dma_wr_buf,
1052 					msgs->len, DMA_TO_DEVICE);
1053 		if (dma_mapping_error(i2c->dev, wpaddr)) {
1054 			i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, false);
1055 
1056 			return -ENOMEM;
1057 		}
1058 
1059 		if (i2c->dev_comp->max_dma_support > 32) {
1060 			reg_4g_mode = upper_32_bits(wpaddr);
1061 			writel(reg_4g_mode, i2c->pdmabase + OFFSET_TX_4G_MODE);
1062 		}
1063 
1064 		writel((u32)wpaddr, i2c->pdmabase + OFFSET_TX_MEM_ADDR);
1065 		writel(msgs->len, i2c->pdmabase + OFFSET_TX_LEN);
1066 	} else {
1067 		writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_INT_FLAG);
1068 		writel(I2C_DMA_CLR_FLAG | dma_sync, i2c->pdmabase + OFFSET_CON);
1069 
1070 		dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 1);
1071 		if (!dma_wr_buf)
1072 			return -ENOMEM;
1073 
1074 		wpaddr = dma_map_single(i2c->dev, dma_wr_buf,
1075 					msgs->len, DMA_TO_DEVICE);
1076 		if (dma_mapping_error(i2c->dev, wpaddr)) {
1077 			i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, false);
1078 
1079 			return -ENOMEM;
1080 		}
1081 
1082 		dma_rd_buf = i2c_get_dma_safe_msg_buf((msgs + 1), 1);
1083 		if (!dma_rd_buf) {
1084 			dma_unmap_single(i2c->dev, wpaddr,
1085 					 msgs->len, DMA_TO_DEVICE);
1086 
1087 			i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, false);
1088 
1089 			return -ENOMEM;
1090 		}
1091 
1092 		rpaddr = dma_map_single(i2c->dev, dma_rd_buf,
1093 					(msgs + 1)->len,
1094 					DMA_FROM_DEVICE);
1095 		if (dma_mapping_error(i2c->dev, rpaddr)) {
1096 			dma_unmap_single(i2c->dev, wpaddr,
1097 					 msgs->len, DMA_TO_DEVICE);
1098 
1099 			i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, false);
1100 			i2c_put_dma_safe_msg_buf(dma_rd_buf, (msgs + 1), false);
1101 
1102 			return -ENOMEM;
1103 		}
1104 
1105 		if (i2c->dev_comp->max_dma_support > 32) {
1106 			reg_4g_mode = upper_32_bits(wpaddr);
1107 			writel(reg_4g_mode, i2c->pdmabase + OFFSET_TX_4G_MODE);
1108 
1109 			reg_4g_mode = upper_32_bits(rpaddr);
1110 			writel(reg_4g_mode, i2c->pdmabase + OFFSET_RX_4G_MODE);
1111 		}
1112 
1113 		writel((u32)wpaddr, i2c->pdmabase + OFFSET_TX_MEM_ADDR);
1114 		writel((u32)rpaddr, i2c->pdmabase + OFFSET_RX_MEM_ADDR);
1115 		writel(msgs->len, i2c->pdmabase + OFFSET_TX_LEN);
1116 		writel((msgs + 1)->len, i2c->pdmabase + OFFSET_RX_LEN);
1117 	}
1118 
1119 	writel(I2C_DMA_START_EN, i2c->pdmabase + OFFSET_EN);
1120 
1121 	if (!i2c->auto_restart) {
1122 		start_reg = I2C_TRANSAC_START;
1123 	} else {
1124 		start_reg = I2C_TRANSAC_START | I2C_RS_MUL_TRIG;
1125 		if (left_num >= 1)
1126 			start_reg |= I2C_RS_MUL_CNFG;
1127 	}
1128 	mtk_i2c_writew(i2c, start_reg, OFFSET_START);
1129 
1130 	ret = wait_for_completion_timeout(&i2c->msg_complete,
1131 					  i2c->adap.timeout);
1132 
1133 	/* Clear interrupt mask */
1134 	mtk_i2c_writew(i2c, ~(restart_flag | I2C_HS_NACKERR | I2C_ACKERR |
1135 			    I2C_ARB_LOST | I2C_TRANSAC_COMP), OFFSET_INTR_MASK);
1136 
1137 	if (i2c->op == I2C_MASTER_WR) {
1138 		dma_unmap_single(i2c->dev, wpaddr,
1139 				 msgs->len, DMA_TO_DEVICE);
1140 
1141 		i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, true);
1142 	} else if (i2c->op == I2C_MASTER_RD) {
1143 		dma_unmap_single(i2c->dev, rpaddr,
1144 				 msgs->len, DMA_FROM_DEVICE);
1145 
1146 		i2c_put_dma_safe_msg_buf(dma_rd_buf, msgs, true);
1147 	} else {
1148 		dma_unmap_single(i2c->dev, wpaddr, msgs->len,
1149 				 DMA_TO_DEVICE);
1150 		dma_unmap_single(i2c->dev, rpaddr, (msgs + 1)->len,
1151 				 DMA_FROM_DEVICE);
1152 
1153 		i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, true);
1154 		i2c_put_dma_safe_msg_buf(dma_rd_buf, (msgs + 1), true);
1155 	}
1156 
1157 	if (ret == 0) {
1158 		dev_dbg(i2c->dev, "addr: %x, transfer timeout\n", msgs->addr);
1159 		i2c_dump_register(i2c);
1160 		mtk_i2c_init_hw(i2c);
1161 		return -ETIMEDOUT;
1162 	}
1163 
1164 	if (i2c->irq_stat & (I2C_HS_NACKERR | I2C_ACKERR)) {
1165 		dev_dbg(i2c->dev, "addr: %x, transfer ACK error\n", msgs->addr);
1166 		mtk_i2c_init_hw(i2c);
1167 		return -ENXIO;
1168 	}
1169 
1170 	return 0;
1171 }
1172 
1173 static int mtk_i2c_transfer(struct i2c_adapter *adap,
1174 			    struct i2c_msg msgs[], int num)
1175 {
1176 	int ret;
1177 	int left_num = num;
1178 	struct mtk_i2c *i2c = i2c_get_adapdata(adap);
1179 
1180 	ret = clk_bulk_enable(I2C_MT65XX_CLK_MAX, i2c->clocks);
1181 	if (ret)
1182 		return ret;
1183 
1184 	i2c->auto_restart = i2c->dev_comp->auto_restart;
1185 
1186 	/* checking if we can skip restart and optimize using WRRD mode */
1187 	if (i2c->auto_restart && num == 2) {
1188 		if (!(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD) &&
1189 		    msgs[0].addr == msgs[1].addr) {
1190 			i2c->auto_restart = 0;
1191 		}
1192 	}
1193 
1194 	if (i2c->auto_restart && num >= 2 &&
1195 		i2c->speed_hz > I2C_MAX_FAST_MODE_PLUS_FREQ)
1196 		/* ignore the first restart irq after the master code,
1197 		 * otherwise the first transfer will be discarded.
1198 		 */
1199 		i2c->ignore_restart_irq = true;
1200 	else
1201 		i2c->ignore_restart_irq = false;
1202 
1203 	while (left_num--) {
1204 		if (!msgs->buf) {
1205 			dev_dbg(i2c->dev, "data buffer is NULL.\n");
1206 			ret = -EINVAL;
1207 			goto err_exit;
1208 		}
1209 
1210 		if (msgs->flags & I2C_M_RD)
1211 			i2c->op = I2C_MASTER_RD;
1212 		else
1213 			i2c->op = I2C_MASTER_WR;
1214 
1215 		if (!i2c->auto_restart) {
1216 			if (num > 1) {
1217 				/* combined two messages into one transaction */
1218 				i2c->op = I2C_MASTER_WRRD;
1219 				left_num--;
1220 			}
1221 		}
1222 
1223 		/* always use DMA mode. */
1224 		ret = mtk_i2c_do_transfer(i2c, msgs, num, left_num);
1225 		if (ret < 0)
1226 			goto err_exit;
1227 
1228 		msgs++;
1229 	}
1230 	/* the return value is number of executed messages */
1231 	ret = num;
1232 
1233 err_exit:
1234 	clk_bulk_disable(I2C_MT65XX_CLK_MAX, i2c->clocks);
1235 	return ret;
1236 }
1237 
1238 static irqreturn_t mtk_i2c_irq(int irqno, void *dev_id)
1239 {
1240 	struct mtk_i2c *i2c = dev_id;
1241 	u16 restart_flag = 0;
1242 	u16 intr_stat;
1243 
1244 	if (i2c->auto_restart)
1245 		restart_flag = I2C_RS_TRANSFER;
1246 
1247 	intr_stat = mtk_i2c_readw(i2c, OFFSET_INTR_STAT);
1248 	mtk_i2c_writew(i2c, intr_stat, OFFSET_INTR_STAT);
1249 
1250 	/*
1251 	 * when occurs ack error, i2c controller generate two interrupts
1252 	 * first is the ack error interrupt, then the complete interrupt
1253 	 * i2c->irq_stat need keep the two interrupt value.
1254 	 */
1255 	i2c->irq_stat |= intr_stat;
1256 
1257 	if (i2c->ignore_restart_irq && (i2c->irq_stat & restart_flag)) {
1258 		i2c->ignore_restart_irq = false;
1259 		i2c->irq_stat = 0;
1260 		mtk_i2c_writew(i2c, I2C_RS_MUL_CNFG | I2C_RS_MUL_TRIG |
1261 				    I2C_TRANSAC_START, OFFSET_START);
1262 	} else {
1263 		if (i2c->irq_stat & (I2C_TRANSAC_COMP | restart_flag))
1264 			complete(&i2c->msg_complete);
1265 	}
1266 
1267 	return IRQ_HANDLED;
1268 }
1269 
1270 static u32 mtk_i2c_functionality(struct i2c_adapter *adap)
1271 {
1272 	if (i2c_check_quirks(adap, I2C_AQ_NO_ZERO_LEN))
1273 		return I2C_FUNC_I2C |
1274 			(I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
1275 	else
1276 		return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
1277 }
1278 
1279 static const struct i2c_algorithm mtk_i2c_algorithm = {
1280 	.master_xfer = mtk_i2c_transfer,
1281 	.functionality = mtk_i2c_functionality,
1282 };
1283 
1284 static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c)
1285 {
1286 	int ret;
1287 
1288 	ret = of_property_read_u32(np, "clock-frequency", &i2c->speed_hz);
1289 	if (ret < 0)
1290 		i2c->speed_hz = I2C_MAX_STANDARD_MODE_FREQ;
1291 
1292 	ret = of_property_read_u32(np, "clock-div", &i2c->clk_src_div);
1293 	if (ret < 0)
1294 		return ret;
1295 
1296 	if (i2c->clk_src_div == 0)
1297 		return -EINVAL;
1298 
1299 	i2c->have_pmic = of_property_read_bool(np, "mediatek,have-pmic");
1300 	i2c->use_push_pull =
1301 		of_property_read_bool(np, "mediatek,use-push-pull");
1302 
1303 	i2c_parse_fw_timings(i2c->dev, &i2c->timing_info, true);
1304 
1305 	return 0;
1306 }
1307 
1308 static int mtk_i2c_probe(struct platform_device *pdev)
1309 {
1310 	int ret = 0;
1311 	struct mtk_i2c *i2c;
1312 	struct resource *res;
1313 	int i, irq, speed_clk;
1314 
1315 	i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
1316 	if (!i2c)
1317 		return -ENOMEM;
1318 
1319 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1320 	i2c->base = devm_ioremap_resource(&pdev->dev, res);
1321 	if (IS_ERR(i2c->base))
1322 		return PTR_ERR(i2c->base);
1323 
1324 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1325 	i2c->pdmabase = devm_ioremap_resource(&pdev->dev, res);
1326 	if (IS_ERR(i2c->pdmabase))
1327 		return PTR_ERR(i2c->pdmabase);
1328 
1329 	irq = platform_get_irq(pdev, 0);
1330 	if (irq < 0)
1331 		return irq;
1332 
1333 	init_completion(&i2c->msg_complete);
1334 
1335 	i2c->dev_comp = of_device_get_match_data(&pdev->dev);
1336 	i2c->adap.dev.of_node = pdev->dev.of_node;
1337 	i2c->dev = &pdev->dev;
1338 	i2c->adap.dev.parent = &pdev->dev;
1339 	i2c->adap.owner = THIS_MODULE;
1340 	i2c->adap.algo = &mtk_i2c_algorithm;
1341 	i2c->adap.quirks = i2c->dev_comp->quirks;
1342 	i2c->adap.timeout = 2 * HZ;
1343 	i2c->adap.retries = 1;
1344 	i2c->adap.bus_regulator = devm_regulator_get_optional(&pdev->dev, "vbus");
1345 	if (IS_ERR(i2c->adap.bus_regulator)) {
1346 		if (PTR_ERR(i2c->adap.bus_regulator) == -ENODEV)
1347 			i2c->adap.bus_regulator = NULL;
1348 		else
1349 			return PTR_ERR(i2c->adap.bus_regulator);
1350 	}
1351 
1352 	ret = mtk_i2c_parse_dt(pdev->dev.of_node, i2c);
1353 	if (ret)
1354 		return -EINVAL;
1355 
1356 	if (i2c->have_pmic && !i2c->dev_comp->pmic_i2c)
1357 		return -EINVAL;
1358 
1359 	/* Fill in clk-bulk IDs */
1360 	for (i = 0; i < I2C_MT65XX_CLK_MAX; i++)
1361 		i2c->clocks[i].id = i2c_mt65xx_clk_ids[i];
1362 
1363 	/* Get clocks one by one, some may be optional */
1364 	i2c->clocks[I2C_MT65XX_CLK_MAIN].clk = devm_clk_get(&pdev->dev, "main");
1365 	if (IS_ERR(i2c->clocks[I2C_MT65XX_CLK_MAIN].clk)) {
1366 		dev_err(&pdev->dev, "cannot get main clock\n");
1367 		return PTR_ERR(i2c->clocks[I2C_MT65XX_CLK_MAIN].clk);
1368 	}
1369 
1370 	i2c->clocks[I2C_MT65XX_CLK_DMA].clk = devm_clk_get(&pdev->dev, "dma");
1371 	if (IS_ERR(i2c->clocks[I2C_MT65XX_CLK_DMA].clk)) {
1372 		dev_err(&pdev->dev, "cannot get dma clock\n");
1373 		return PTR_ERR(i2c->clocks[I2C_MT65XX_CLK_DMA].clk);
1374 	}
1375 
1376 	i2c->clocks[I2C_MT65XX_CLK_ARB].clk = devm_clk_get_optional(&pdev->dev, "arb");
1377 	if (IS_ERR(i2c->clocks[I2C_MT65XX_CLK_ARB].clk))
1378 		return PTR_ERR(i2c->clocks[I2C_MT65XX_CLK_ARB].clk);
1379 
1380 	if (i2c->have_pmic) {
1381 		i2c->clocks[I2C_MT65XX_CLK_PMIC].clk = devm_clk_get(&pdev->dev, "pmic");
1382 		if (IS_ERR(i2c->clocks[I2C_MT65XX_CLK_PMIC].clk)) {
1383 			dev_err(&pdev->dev, "cannot get pmic clock\n");
1384 			return PTR_ERR(i2c->clocks[I2C_MT65XX_CLK_PMIC].clk);
1385 		}
1386 		speed_clk = I2C_MT65XX_CLK_PMIC;
1387 	} else {
1388 		i2c->clocks[I2C_MT65XX_CLK_PMIC].clk = NULL;
1389 		speed_clk = I2C_MT65XX_CLK_MAIN;
1390 	}
1391 
1392 	strlcpy(i2c->adap.name, I2C_DRV_NAME, sizeof(i2c->adap.name));
1393 
1394 	ret = mtk_i2c_set_speed(i2c, clk_get_rate(i2c->clocks[speed_clk].clk));
1395 	if (ret) {
1396 		dev_err(&pdev->dev, "Failed to set the speed.\n");
1397 		return -EINVAL;
1398 	}
1399 
1400 	if (i2c->dev_comp->max_dma_support > 32) {
1401 		ret = dma_set_mask(&pdev->dev,
1402 				DMA_BIT_MASK(i2c->dev_comp->max_dma_support));
1403 		if (ret) {
1404 			dev_err(&pdev->dev, "dma_set_mask return error.\n");
1405 			return ret;
1406 		}
1407 	}
1408 
1409 	ret = clk_bulk_prepare_enable(I2C_MT65XX_CLK_MAX, i2c->clocks);
1410 	if (ret) {
1411 		dev_err(&pdev->dev, "clock enable failed!\n");
1412 		return ret;
1413 	}
1414 	mtk_i2c_init_hw(i2c);
1415 	clk_bulk_disable(I2C_MT65XX_CLK_MAX, i2c->clocks);
1416 
1417 	ret = devm_request_irq(&pdev->dev, irq, mtk_i2c_irq,
1418 			       IRQF_NO_SUSPEND | IRQF_TRIGGER_NONE,
1419 			       dev_name(&pdev->dev), i2c);
1420 	if (ret < 0) {
1421 		dev_err(&pdev->dev,
1422 			"Request I2C IRQ %d fail\n", irq);
1423 		goto err_bulk_unprepare;
1424 	}
1425 
1426 	i2c_set_adapdata(&i2c->adap, i2c);
1427 	ret = i2c_add_adapter(&i2c->adap);
1428 	if (ret)
1429 		goto err_bulk_unprepare;
1430 
1431 	platform_set_drvdata(pdev, i2c);
1432 
1433 	return 0;
1434 
1435 err_bulk_unprepare:
1436 	clk_bulk_unprepare(I2C_MT65XX_CLK_MAX, i2c->clocks);
1437 
1438 	return ret;
1439 }
1440 
1441 static int mtk_i2c_remove(struct platform_device *pdev)
1442 {
1443 	struct mtk_i2c *i2c = platform_get_drvdata(pdev);
1444 
1445 	i2c_del_adapter(&i2c->adap);
1446 
1447 	clk_bulk_unprepare(I2C_MT65XX_CLK_MAX, i2c->clocks);
1448 
1449 	return 0;
1450 }
1451 
1452 #ifdef CONFIG_PM_SLEEP
1453 static int mtk_i2c_suspend_noirq(struct device *dev)
1454 {
1455 	struct mtk_i2c *i2c = dev_get_drvdata(dev);
1456 
1457 	i2c_mark_adapter_suspended(&i2c->adap);
1458 	clk_bulk_unprepare(I2C_MT65XX_CLK_MAX, i2c->clocks);
1459 
1460 	return 0;
1461 }
1462 
1463 static int mtk_i2c_resume_noirq(struct device *dev)
1464 {
1465 	int ret;
1466 	struct mtk_i2c *i2c = dev_get_drvdata(dev);
1467 
1468 	ret = clk_bulk_prepare_enable(I2C_MT65XX_CLK_MAX, i2c->clocks);
1469 	if (ret) {
1470 		dev_err(dev, "clock enable failed!\n");
1471 		return ret;
1472 	}
1473 
1474 	mtk_i2c_init_hw(i2c);
1475 
1476 	clk_bulk_disable(I2C_MT65XX_CLK_MAX, i2c->clocks);
1477 
1478 	i2c_mark_adapter_resumed(&i2c->adap);
1479 
1480 	return 0;
1481 }
1482 #endif
1483 
1484 static const struct dev_pm_ops mtk_i2c_pm = {
1485 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(mtk_i2c_suspend_noirq,
1486 				      mtk_i2c_resume_noirq)
1487 };
1488 
1489 static struct platform_driver mtk_i2c_driver = {
1490 	.probe = mtk_i2c_probe,
1491 	.remove = mtk_i2c_remove,
1492 	.driver = {
1493 		.name = I2C_DRV_NAME,
1494 		.pm = &mtk_i2c_pm,
1495 		.of_match_table = of_match_ptr(mtk_i2c_of_match),
1496 	},
1497 };
1498 
1499 module_platform_driver(mtk_i2c_driver);
1500 
1501 MODULE_LICENSE("GPL v2");
1502 MODULE_DESCRIPTION("MediaTek I2C Bus Driver");
1503 MODULE_AUTHOR("Xudong Chen <xudong.chen@mediatek.com>");
1504