xref: /openbmc/linux/drivers/i2c/busses/i2c-mt65xx.c (revision 34facb04)
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/kernel.h>
19 #include <linux/mm.h>
20 #include <linux/module.h>
21 #include <linux/of_address.h>
22 #include <linux/of_device.h>
23 #include <linux/of_irq.h>
24 #include <linux/platform_device.h>
25 #include <linux/scatterlist.h>
26 #include <linux/sched.h>
27 #include <linux/slab.h>
28 
29 #define I2C_RS_TRANSFER			(1 << 4)
30 #define I2C_ARB_LOST			(1 << 3)
31 #define I2C_HS_NACKERR			(1 << 2)
32 #define I2C_ACKERR			(1 << 1)
33 #define I2C_TRANSAC_COMP		(1 << 0)
34 #define I2C_TRANSAC_START		(1 << 0)
35 #define I2C_RS_MUL_CNFG			(1 << 15)
36 #define I2C_RS_MUL_TRIG			(1 << 14)
37 #define I2C_DCM_DISABLE			0x0000
38 #define I2C_IO_CONFIG_OPEN_DRAIN	0x0003
39 #define I2C_IO_CONFIG_PUSH_PULL		0x0000
40 #define I2C_SOFT_RST			0x0001
41 #define I2C_FIFO_ADDR_CLR		0x0001
42 #define I2C_DELAY_LEN			0x0002
43 #define I2C_TIME_CLR_VALUE		0x0000
44 #define I2C_TIME_DEFAULT_VALUE		0x0003
45 #define I2C_WRRD_TRANAC_VALUE		0x0002
46 #define I2C_RD_TRANAC_VALUE		0x0001
47 #define I2C_SCL_MIS_COMP_VALUE		0x0000
48 
49 #define I2C_DMA_CON_TX			0x0000
50 #define I2C_DMA_CON_RX			0x0001
51 #define I2C_DMA_START_EN		0x0001
52 #define I2C_DMA_INT_FLAG_NONE		0x0000
53 #define I2C_DMA_CLR_FLAG		0x0000
54 #define I2C_DMA_HARD_RST		0x0002
55 #define I2C_DMA_4G_MODE			0x0001
56 
57 #define MAX_SAMPLE_CNT_DIV		8
58 #define MAX_STEP_CNT_DIV		64
59 #define MAX_CLOCK_DIV			256
60 #define MAX_HS_STEP_CNT_DIV		8
61 #define I2C_STANDARD_MODE_BUFFER	(1000 / 2)
62 #define I2C_FAST_MODE_BUFFER		(300 / 2)
63 #define I2C_FAST_MODE_PLUS_BUFFER	(20 / 2)
64 
65 #define I2C_CONTROL_RS                  (0x1 << 1)
66 #define I2C_CONTROL_DMA_EN              (0x1 << 2)
67 #define I2C_CONTROL_CLK_EXT_EN          (0x1 << 3)
68 #define I2C_CONTROL_DIR_CHANGE          (0x1 << 4)
69 #define I2C_CONTROL_ACKERR_DET_EN       (0x1 << 5)
70 #define I2C_CONTROL_TRANSFER_LEN_CHANGE (0x1 << 6)
71 #define I2C_CONTROL_DMAACK_EN           (0x1 << 8)
72 #define I2C_CONTROL_ASYNC_MODE          (0x1 << 9)
73 #define I2C_CONTROL_WRAPPER             (0x1 << 0)
74 
75 #define I2C_DRV_NAME		"i2c-mt65xx"
76 
77 enum DMA_REGS_OFFSET {
78 	OFFSET_INT_FLAG = 0x0,
79 	OFFSET_INT_EN = 0x04,
80 	OFFSET_EN = 0x08,
81 	OFFSET_RST = 0x0c,
82 	OFFSET_CON = 0x18,
83 	OFFSET_TX_MEM_ADDR = 0x1c,
84 	OFFSET_RX_MEM_ADDR = 0x20,
85 	OFFSET_TX_LEN = 0x24,
86 	OFFSET_RX_LEN = 0x28,
87 	OFFSET_TX_4G_MODE = 0x54,
88 	OFFSET_RX_4G_MODE = 0x58,
89 };
90 
91 enum i2c_trans_st_rs {
92 	I2C_TRANS_STOP = 0,
93 	I2C_TRANS_REPEATED_START,
94 };
95 
96 enum mtk_trans_op {
97 	I2C_MASTER_WR = 1,
98 	I2C_MASTER_RD,
99 	I2C_MASTER_WRRD,
100 };
101 
102 enum I2C_REGS_OFFSET {
103 	OFFSET_DATA_PORT,
104 	OFFSET_SLAVE_ADDR,
105 	OFFSET_INTR_MASK,
106 	OFFSET_INTR_STAT,
107 	OFFSET_CONTROL,
108 	OFFSET_TRANSFER_LEN,
109 	OFFSET_TRANSAC_LEN,
110 	OFFSET_DELAY_LEN,
111 	OFFSET_TIMING,
112 	OFFSET_START,
113 	OFFSET_EXT_CONF,
114 	OFFSET_FIFO_STAT,
115 	OFFSET_FIFO_THRESH,
116 	OFFSET_FIFO_ADDR_CLR,
117 	OFFSET_IO_CONFIG,
118 	OFFSET_RSV_DEBUG,
119 	OFFSET_HS,
120 	OFFSET_SOFTRESET,
121 	OFFSET_DCM_EN,
122 	OFFSET_PATH_DIR,
123 	OFFSET_DEBUGSTAT,
124 	OFFSET_DEBUGCTRL,
125 	OFFSET_TRANSFER_LEN_AUX,
126 	OFFSET_CLOCK_DIV,
127 	OFFSET_LTIMING,
128 	OFFSET_SCL_HIGH_LOW_RATIO,
129 	OFFSET_HS_SCL_HIGH_LOW_RATIO,
130 	OFFSET_SCL_MIS_COMP_POINT,
131 	OFFSET_STA_STO_AC_TIMING,
132 	OFFSET_HS_STA_STO_AC_TIMING,
133 	OFFSET_SDA_TIMING,
134 };
135 
136 static const u16 mt_i2c_regs_v1[] = {
137 	[OFFSET_DATA_PORT] = 0x0,
138 	[OFFSET_SLAVE_ADDR] = 0x4,
139 	[OFFSET_INTR_MASK] = 0x8,
140 	[OFFSET_INTR_STAT] = 0xc,
141 	[OFFSET_CONTROL] = 0x10,
142 	[OFFSET_TRANSFER_LEN] = 0x14,
143 	[OFFSET_TRANSAC_LEN] = 0x18,
144 	[OFFSET_DELAY_LEN] = 0x1c,
145 	[OFFSET_TIMING] = 0x20,
146 	[OFFSET_START] = 0x24,
147 	[OFFSET_EXT_CONF] = 0x28,
148 	[OFFSET_FIFO_STAT] = 0x30,
149 	[OFFSET_FIFO_THRESH] = 0x34,
150 	[OFFSET_FIFO_ADDR_CLR] = 0x38,
151 	[OFFSET_IO_CONFIG] = 0x40,
152 	[OFFSET_RSV_DEBUG] = 0x44,
153 	[OFFSET_HS] = 0x48,
154 	[OFFSET_SOFTRESET] = 0x50,
155 	[OFFSET_DCM_EN] = 0x54,
156 	[OFFSET_PATH_DIR] = 0x60,
157 	[OFFSET_DEBUGSTAT] = 0x64,
158 	[OFFSET_DEBUGCTRL] = 0x68,
159 	[OFFSET_TRANSFER_LEN_AUX] = 0x6c,
160 	[OFFSET_CLOCK_DIV] = 0x70,
161 	[OFFSET_SCL_HIGH_LOW_RATIO] = 0x74,
162 	[OFFSET_HS_SCL_HIGH_LOW_RATIO] = 0x78,
163 	[OFFSET_SCL_MIS_COMP_POINT] = 0x7C,
164 	[OFFSET_STA_STO_AC_TIMING] = 0x80,
165 	[OFFSET_HS_STA_STO_AC_TIMING] = 0x84,
166 	[OFFSET_SDA_TIMING] = 0x88,
167 };
168 
169 static const u16 mt_i2c_regs_v2[] = {
170 	[OFFSET_DATA_PORT] = 0x0,
171 	[OFFSET_SLAVE_ADDR] = 0x4,
172 	[OFFSET_INTR_MASK] = 0x8,
173 	[OFFSET_INTR_STAT] = 0xc,
174 	[OFFSET_CONTROL] = 0x10,
175 	[OFFSET_TRANSFER_LEN] = 0x14,
176 	[OFFSET_TRANSAC_LEN] = 0x18,
177 	[OFFSET_DELAY_LEN] = 0x1c,
178 	[OFFSET_TIMING] = 0x20,
179 	[OFFSET_START] = 0x24,
180 	[OFFSET_EXT_CONF] = 0x28,
181 	[OFFSET_LTIMING] = 0x2c,
182 	[OFFSET_HS] = 0x30,
183 	[OFFSET_IO_CONFIG] = 0x34,
184 	[OFFSET_FIFO_ADDR_CLR] = 0x38,
185 	[OFFSET_SDA_TIMING] = 0x3c,
186 	[OFFSET_TRANSFER_LEN_AUX] = 0x44,
187 	[OFFSET_CLOCK_DIV] = 0x48,
188 	[OFFSET_SOFTRESET] = 0x50,
189 	[OFFSET_SCL_MIS_COMP_POINT] = 0x90,
190 	[OFFSET_DEBUGSTAT] = 0xe0,
191 	[OFFSET_DEBUGCTRL] = 0xe8,
192 	[OFFSET_FIFO_STAT] = 0xf4,
193 	[OFFSET_FIFO_THRESH] = 0xf8,
194 	[OFFSET_DCM_EN] = 0xf88,
195 };
196 
197 struct mtk_i2c_compatible {
198 	const struct i2c_adapter_quirks *quirks;
199 	const u16 *regs;
200 	unsigned char pmic_i2c: 1;
201 	unsigned char dcm: 1;
202 	unsigned char auto_restart: 1;
203 	unsigned char aux_len_reg: 1;
204 	unsigned char support_33bits: 1;
205 	unsigned char timing_adjust: 1;
206 	unsigned char dma_sync: 1;
207 	unsigned char ltiming_adjust: 1;
208 };
209 
210 struct mtk_i2c_ac_timing {
211 	u16 htiming;
212 	u16 ltiming;
213 	u16 hs;
214 	u16 ext;
215 	u16 inter_clk_div;
216 	u16 scl_hl_ratio;
217 	u16 hs_scl_hl_ratio;
218 	u16 sta_stop;
219 	u16 hs_sta_stop;
220 	u16 sda_timing;
221 };
222 
223 struct mtk_i2c {
224 	struct i2c_adapter adap;	/* i2c host adapter */
225 	struct device *dev;
226 	struct completion msg_complete;
227 
228 	/* set in i2c probe */
229 	void __iomem *base;		/* i2c base addr */
230 	void __iomem *pdmabase;		/* dma base address*/
231 	struct clk *clk_main;		/* main clock for i2c bus */
232 	struct clk *clk_dma;		/* DMA clock for i2c via DMA */
233 	struct clk *clk_pmic;		/* PMIC clock for i2c from PMIC */
234 	struct clk *clk_arb;		/* Arbitrator clock for i2c */
235 	bool have_pmic;			/* can use i2c pins from PMIC */
236 	bool use_push_pull;		/* IO config push-pull mode */
237 
238 	u16 irq_stat;			/* interrupt status */
239 	unsigned int clk_src_div;
240 	unsigned int speed_hz;		/* The speed in transfer */
241 	enum mtk_trans_op op;
242 	u16 timing_reg;
243 	u16 high_speed_reg;
244 	u16 ltiming_reg;
245 	unsigned char auto_restart;
246 	bool ignore_restart_irq;
247 	struct mtk_i2c_ac_timing ac_timing;
248 	const struct mtk_i2c_compatible *dev_comp;
249 };
250 
251 /**
252  * struct i2c_spec_values:
253  * min_low_ns: min LOW period of the SCL clock
254  * min_su_sta_ns: min set-up time for a repeated START condition
255  * max_hd_dat_ns: max data hold time
256  * min_su_dat_ns: min data set-up time
257  */
258 struct i2c_spec_values {
259 	unsigned int min_low_ns;
260 	unsigned int min_high_ns;
261 	unsigned int min_su_sta_ns;
262 	unsigned int max_hd_dat_ns;
263 	unsigned int min_su_dat_ns;
264 };
265 
266 static const struct i2c_spec_values standard_mode_spec = {
267 	.min_low_ns = 4700 + I2C_STANDARD_MODE_BUFFER,
268 	.min_su_sta_ns = 4700 + I2C_STANDARD_MODE_BUFFER,
269 	.max_hd_dat_ns = 3450 - I2C_STANDARD_MODE_BUFFER,
270 	.min_su_dat_ns = 250 + I2C_STANDARD_MODE_BUFFER,
271 };
272 
273 static const struct i2c_spec_values fast_mode_spec = {
274 	.min_low_ns = 1300 + I2C_FAST_MODE_BUFFER,
275 	.min_su_sta_ns = 600 + I2C_FAST_MODE_BUFFER,
276 	.max_hd_dat_ns = 900 - I2C_FAST_MODE_BUFFER,
277 	.min_su_dat_ns = 100 + I2C_FAST_MODE_BUFFER,
278 };
279 
280 static const struct i2c_spec_values fast_mode_plus_spec = {
281 	.min_low_ns = 500 + I2C_FAST_MODE_PLUS_BUFFER,
282 	.min_su_sta_ns = 260 + I2C_FAST_MODE_PLUS_BUFFER,
283 	.max_hd_dat_ns = 400 - I2C_FAST_MODE_PLUS_BUFFER,
284 	.min_su_dat_ns = 50 + I2C_FAST_MODE_PLUS_BUFFER,
285 };
286 
287 static const struct i2c_adapter_quirks mt6577_i2c_quirks = {
288 	.flags = I2C_AQ_COMB_WRITE_THEN_READ,
289 	.max_num_msgs = 1,
290 	.max_write_len = 255,
291 	.max_read_len = 255,
292 	.max_comb_1st_msg_len = 255,
293 	.max_comb_2nd_msg_len = 31,
294 };
295 
296 static const struct i2c_adapter_quirks mt7622_i2c_quirks = {
297 	.max_num_msgs = 255,
298 };
299 
300 static const struct i2c_adapter_quirks mt8183_i2c_quirks = {
301 	.flags = I2C_AQ_NO_ZERO_LEN,
302 };
303 
304 static const struct mtk_i2c_compatible mt2712_compat = {
305 	.regs = mt_i2c_regs_v1,
306 	.pmic_i2c = 0,
307 	.dcm = 1,
308 	.auto_restart = 1,
309 	.aux_len_reg = 1,
310 	.support_33bits = 1,
311 	.timing_adjust = 1,
312 	.dma_sync = 0,
313 	.ltiming_adjust = 0,
314 };
315 
316 static const struct mtk_i2c_compatible mt6577_compat = {
317 	.quirks = &mt6577_i2c_quirks,
318 	.regs = mt_i2c_regs_v1,
319 	.pmic_i2c = 0,
320 	.dcm = 1,
321 	.auto_restart = 0,
322 	.aux_len_reg = 0,
323 	.support_33bits = 0,
324 	.timing_adjust = 0,
325 	.dma_sync = 0,
326 	.ltiming_adjust = 0,
327 };
328 
329 static const struct mtk_i2c_compatible mt6589_compat = {
330 	.quirks = &mt6577_i2c_quirks,
331 	.regs = mt_i2c_regs_v1,
332 	.pmic_i2c = 1,
333 	.dcm = 0,
334 	.auto_restart = 0,
335 	.aux_len_reg = 0,
336 	.support_33bits = 0,
337 	.timing_adjust = 0,
338 	.dma_sync = 0,
339 	.ltiming_adjust = 0,
340 };
341 
342 static const struct mtk_i2c_compatible mt7622_compat = {
343 	.quirks = &mt7622_i2c_quirks,
344 	.regs = mt_i2c_regs_v1,
345 	.pmic_i2c = 0,
346 	.dcm = 1,
347 	.auto_restart = 1,
348 	.aux_len_reg = 1,
349 	.support_33bits = 0,
350 	.timing_adjust = 0,
351 	.dma_sync = 0,
352 	.ltiming_adjust = 0,
353 };
354 
355 static const struct mtk_i2c_compatible mt8173_compat = {
356 	.regs = mt_i2c_regs_v1,
357 	.pmic_i2c = 0,
358 	.dcm = 1,
359 	.auto_restart = 1,
360 	.aux_len_reg = 1,
361 	.support_33bits = 1,
362 	.timing_adjust = 0,
363 	.dma_sync = 0,
364 	.ltiming_adjust = 0,
365 };
366 
367 static const struct mtk_i2c_compatible mt8183_compat = {
368 	.quirks = &mt8183_i2c_quirks,
369 	.regs = mt_i2c_regs_v2,
370 	.pmic_i2c = 0,
371 	.dcm = 0,
372 	.auto_restart = 1,
373 	.aux_len_reg = 1,
374 	.support_33bits = 1,
375 	.timing_adjust = 1,
376 	.dma_sync = 1,
377 	.ltiming_adjust = 1,
378 };
379 
380 static const struct of_device_id mtk_i2c_of_match[] = {
381 	{ .compatible = "mediatek,mt2712-i2c", .data = &mt2712_compat },
382 	{ .compatible = "mediatek,mt6577-i2c", .data = &mt6577_compat },
383 	{ .compatible = "mediatek,mt6589-i2c", .data = &mt6589_compat },
384 	{ .compatible = "mediatek,mt7622-i2c", .data = &mt7622_compat },
385 	{ .compatible = "mediatek,mt8173-i2c", .data = &mt8173_compat },
386 	{ .compatible = "mediatek,mt8183-i2c", .data = &mt8183_compat },
387 	{}
388 };
389 MODULE_DEVICE_TABLE(of, mtk_i2c_of_match);
390 
391 static u16 mtk_i2c_readw(struct mtk_i2c *i2c, enum I2C_REGS_OFFSET reg)
392 {
393 	return readw(i2c->base + i2c->dev_comp->regs[reg]);
394 }
395 
396 static void mtk_i2c_writew(struct mtk_i2c *i2c, u16 val,
397 			   enum I2C_REGS_OFFSET reg)
398 {
399 	writew(val, i2c->base + i2c->dev_comp->regs[reg]);
400 }
401 
402 static int mtk_i2c_clock_enable(struct mtk_i2c *i2c)
403 {
404 	int ret;
405 
406 	ret = clk_prepare_enable(i2c->clk_dma);
407 	if (ret)
408 		return ret;
409 
410 	ret = clk_prepare_enable(i2c->clk_main);
411 	if (ret)
412 		goto err_main;
413 
414 	if (i2c->have_pmic) {
415 		ret = clk_prepare_enable(i2c->clk_pmic);
416 		if (ret)
417 			goto err_pmic;
418 	}
419 
420 	if (i2c->clk_arb) {
421 		ret = clk_prepare_enable(i2c->clk_arb);
422 		if (ret)
423 			goto err_arb;
424 	}
425 
426 	return 0;
427 
428 err_arb:
429 	if (i2c->have_pmic)
430 		clk_disable_unprepare(i2c->clk_pmic);
431 err_pmic:
432 	clk_disable_unprepare(i2c->clk_main);
433 err_main:
434 	clk_disable_unprepare(i2c->clk_dma);
435 
436 	return ret;
437 }
438 
439 static void mtk_i2c_clock_disable(struct mtk_i2c *i2c)
440 {
441 	if (i2c->clk_arb)
442 		clk_disable_unprepare(i2c->clk_arb);
443 
444 	if (i2c->have_pmic)
445 		clk_disable_unprepare(i2c->clk_pmic);
446 
447 	clk_disable_unprepare(i2c->clk_main);
448 	clk_disable_unprepare(i2c->clk_dma);
449 }
450 
451 static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
452 {
453 	u16 control_reg;
454 
455 	mtk_i2c_writew(i2c, I2C_SOFT_RST, OFFSET_SOFTRESET);
456 
457 	/* Set ioconfig */
458 	if (i2c->use_push_pull)
459 		mtk_i2c_writew(i2c, I2C_IO_CONFIG_PUSH_PULL, OFFSET_IO_CONFIG);
460 	else
461 		mtk_i2c_writew(i2c, I2C_IO_CONFIG_OPEN_DRAIN, OFFSET_IO_CONFIG);
462 
463 	if (i2c->dev_comp->dcm)
464 		mtk_i2c_writew(i2c, I2C_DCM_DISABLE, OFFSET_DCM_EN);
465 
466 	mtk_i2c_writew(i2c, i2c->timing_reg, OFFSET_TIMING);
467 	mtk_i2c_writew(i2c, i2c->high_speed_reg, OFFSET_HS);
468 	if (i2c->dev_comp->ltiming_adjust)
469 		mtk_i2c_writew(i2c, i2c->ltiming_reg, OFFSET_LTIMING);
470 
471 	if (i2c->dev_comp->timing_adjust) {
472 		mtk_i2c_writew(i2c, i2c->ac_timing.ext, OFFSET_EXT_CONF);
473 		mtk_i2c_writew(i2c, i2c->ac_timing.inter_clk_div,
474 			       OFFSET_CLOCK_DIV);
475 		mtk_i2c_writew(i2c, I2C_SCL_MIS_COMP_VALUE,
476 			       OFFSET_SCL_MIS_COMP_POINT);
477 		mtk_i2c_writew(i2c, i2c->ac_timing.sda_timing,
478 			       OFFSET_SDA_TIMING);
479 
480 		if (i2c->dev_comp->ltiming_adjust) {
481 			mtk_i2c_writew(i2c, i2c->ac_timing.htiming,
482 				       OFFSET_TIMING);
483 			mtk_i2c_writew(i2c, i2c->ac_timing.hs, OFFSET_HS);
484 			mtk_i2c_writew(i2c, i2c->ac_timing.ltiming,
485 				       OFFSET_LTIMING);
486 		} else {
487 			mtk_i2c_writew(i2c, i2c->ac_timing.scl_hl_ratio,
488 				       OFFSET_SCL_HIGH_LOW_RATIO);
489 			mtk_i2c_writew(i2c, i2c->ac_timing.hs_scl_hl_ratio,
490 				       OFFSET_HS_SCL_HIGH_LOW_RATIO);
491 			mtk_i2c_writew(i2c, i2c->ac_timing.sta_stop,
492 				       OFFSET_STA_STO_AC_TIMING);
493 			mtk_i2c_writew(i2c, i2c->ac_timing.hs_sta_stop,
494 				       OFFSET_HS_STA_STO_AC_TIMING);
495 		}
496 	}
497 
498 	/* If use i2c pin from PMIC mt6397 side, need set PATH_DIR first */
499 	if (i2c->have_pmic)
500 		mtk_i2c_writew(i2c, I2C_CONTROL_WRAPPER, OFFSET_PATH_DIR);
501 
502 	control_reg = I2C_CONTROL_ACKERR_DET_EN |
503 		      I2C_CONTROL_CLK_EXT_EN | I2C_CONTROL_DMA_EN;
504 	if (i2c->dev_comp->dma_sync)
505 		control_reg |= I2C_CONTROL_DMAACK_EN | I2C_CONTROL_ASYNC_MODE;
506 
507 	mtk_i2c_writew(i2c, control_reg, OFFSET_CONTROL);
508 	mtk_i2c_writew(i2c, I2C_DELAY_LEN, OFFSET_DELAY_LEN);
509 
510 	writel(I2C_DMA_HARD_RST, i2c->pdmabase + OFFSET_RST);
511 	udelay(50);
512 	writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
513 }
514 
515 static const struct i2c_spec_values *mtk_i2c_get_spec(unsigned int speed)
516 {
517 	if (speed <= I2C_MAX_STANDARD_MODE_FREQ)
518 		return &standard_mode_spec;
519 	else if (speed <= I2C_MAX_FAST_MODE_FREQ)
520 		return &fast_mode_spec;
521 	else
522 		return &fast_mode_plus_spec;
523 }
524 
525 static int mtk_i2c_max_step_cnt(unsigned int target_speed)
526 {
527 	if (target_speed > I2C_MAX_FAST_MODE_FREQ)
528 		return MAX_HS_STEP_CNT_DIV;
529 	else
530 		return MAX_STEP_CNT_DIV;
531 }
532 
533 /*
534  * Check and Calculate i2c ac-timing
535  *
536  * Hardware design:
537  * sample_ns = (1000000000 * (sample_cnt + 1)) / clk_src
538  * xxx_cnt_div =  spec->min_xxx_ns / sample_ns
539  *
540  * Sample_ns is rounded down for xxx_cnt_div would be greater
541  * than the smallest spec.
542  * The sda_timing is chosen as the middle value between
543  * the largest and smallest.
544  */
545 static int mtk_i2c_check_ac_timing(struct mtk_i2c *i2c,
546 				   unsigned int clk_src,
547 				   unsigned int check_speed,
548 				   unsigned int step_cnt,
549 				   unsigned int sample_cnt)
550 {
551 	const struct i2c_spec_values *spec;
552 	unsigned int su_sta_cnt, low_cnt, high_cnt, max_step_cnt;
553 	unsigned int sda_max, sda_min, clk_ns, max_sta_cnt = 0x3f;
554 	unsigned int sample_ns = div_u64(1000000000ULL * (sample_cnt + 1),
555 					 clk_src);
556 
557 	if (!i2c->dev_comp->timing_adjust)
558 		return 0;
559 
560 	if (i2c->dev_comp->ltiming_adjust)
561 		max_sta_cnt = 0x100;
562 
563 	spec = mtk_i2c_get_spec(check_speed);
564 
565 	if (i2c->dev_comp->ltiming_adjust)
566 		clk_ns = 1000000000 / clk_src;
567 	else
568 		clk_ns = sample_ns / 2;
569 
570 	su_sta_cnt = DIV_ROUND_UP(spec->min_su_sta_ns, clk_ns);
571 	if (su_sta_cnt > max_sta_cnt)
572 		return -1;
573 
574 	low_cnt = DIV_ROUND_UP(spec->min_low_ns, sample_ns);
575 	max_step_cnt = mtk_i2c_max_step_cnt(check_speed);
576 	if ((2 * step_cnt) > low_cnt && low_cnt < max_step_cnt) {
577 		if (low_cnt > step_cnt) {
578 			high_cnt = 2 * step_cnt - low_cnt;
579 		} else {
580 			high_cnt = step_cnt;
581 			low_cnt = step_cnt;
582 		}
583 	} else {
584 		return -2;
585 	}
586 
587 	sda_max = spec->max_hd_dat_ns / sample_ns;
588 	if (sda_max > low_cnt)
589 		sda_max = 0;
590 
591 	sda_min = DIV_ROUND_UP(spec->min_su_dat_ns, sample_ns);
592 	if (sda_min < low_cnt)
593 		sda_min = 0;
594 
595 	if (sda_min > sda_max)
596 		return -3;
597 
598 	if (check_speed > I2C_MAX_FAST_MODE_FREQ) {
599 		if (i2c->dev_comp->ltiming_adjust) {
600 			i2c->ac_timing.hs = I2C_TIME_DEFAULT_VALUE |
601 				(sample_cnt << 12) | (high_cnt << 8);
602 			i2c->ac_timing.ltiming &= ~GENMASK(15, 9);
603 			i2c->ac_timing.ltiming |= (sample_cnt << 12) |
604 				(low_cnt << 9);
605 			i2c->ac_timing.ext &= ~GENMASK(7, 1);
606 			i2c->ac_timing.ext |= (su_sta_cnt << 1) | (1 << 0);
607 		} else {
608 			i2c->ac_timing.hs_scl_hl_ratio = (1 << 12) |
609 				(high_cnt << 6) | low_cnt;
610 			i2c->ac_timing.hs_sta_stop = (su_sta_cnt << 8) |
611 				su_sta_cnt;
612 		}
613 		i2c->ac_timing.sda_timing &= ~GENMASK(11, 6);
614 		i2c->ac_timing.sda_timing |= (1 << 12) |
615 			((sda_max + sda_min) / 2) << 6;
616 	} else {
617 		if (i2c->dev_comp->ltiming_adjust) {
618 			i2c->ac_timing.htiming = (sample_cnt << 8) | (high_cnt);
619 			i2c->ac_timing.ltiming = (sample_cnt << 6) | (low_cnt);
620 			i2c->ac_timing.ext = (su_sta_cnt << 8) | (1 << 0);
621 		} else {
622 			i2c->ac_timing.scl_hl_ratio = (1 << 12) |
623 				(high_cnt << 6) | low_cnt;
624 			i2c->ac_timing.sta_stop = (su_sta_cnt << 8) |
625 				su_sta_cnt;
626 		}
627 
628 		i2c->ac_timing.sda_timing = (1 << 12) |
629 			(sda_max + sda_min) / 2;
630 	}
631 
632 	return 0;
633 }
634 
635 /*
636  * Calculate i2c port speed
637  *
638  * Hardware design:
639  * i2c_bus_freq = parent_clk / (clock_div * 2 * sample_cnt * step_cnt)
640  * clock_div: fixed in hardware, but may be various in different SoCs
641  *
642  * The calculation want to pick the highest bus frequency that is still
643  * less than or equal to i2c->speed_hz. The calculation try to get
644  * sample_cnt and step_cn
645  */
646 static int mtk_i2c_calculate_speed(struct mtk_i2c *i2c, unsigned int clk_src,
647 				   unsigned int target_speed,
648 				   unsigned int *timing_step_cnt,
649 				   unsigned int *timing_sample_cnt)
650 {
651 	unsigned int step_cnt;
652 	unsigned int sample_cnt;
653 	unsigned int max_step_cnt;
654 	unsigned int base_sample_cnt = MAX_SAMPLE_CNT_DIV;
655 	unsigned int base_step_cnt;
656 	unsigned int opt_div;
657 	unsigned int best_mul;
658 	unsigned int cnt_mul;
659 	int ret = -EINVAL;
660 
661 	if (target_speed > I2C_MAX_FAST_MODE_PLUS_FREQ)
662 		target_speed = I2C_MAX_FAST_MODE_PLUS_FREQ;
663 
664 	max_step_cnt = mtk_i2c_max_step_cnt(target_speed);
665 	base_step_cnt = max_step_cnt;
666 	/* Find the best combination */
667 	opt_div = DIV_ROUND_UP(clk_src >> 1, target_speed);
668 	best_mul = MAX_SAMPLE_CNT_DIV * max_step_cnt;
669 
670 	/* Search for the best pair (sample_cnt, step_cnt) with
671 	 * 0 < sample_cnt < MAX_SAMPLE_CNT_DIV
672 	 * 0 < step_cnt < max_step_cnt
673 	 * sample_cnt * step_cnt >= opt_div
674 	 * optimizing for sample_cnt * step_cnt being minimal
675 	 */
676 	for (sample_cnt = 1; sample_cnt <= MAX_SAMPLE_CNT_DIV; sample_cnt++) {
677 		step_cnt = DIV_ROUND_UP(opt_div, sample_cnt);
678 		cnt_mul = step_cnt * sample_cnt;
679 		if (step_cnt > max_step_cnt)
680 			continue;
681 
682 		if (cnt_mul < best_mul) {
683 			ret = mtk_i2c_check_ac_timing(i2c, clk_src,
684 				target_speed, step_cnt - 1, sample_cnt - 1);
685 			if (ret)
686 				continue;
687 
688 			best_mul = cnt_mul;
689 			base_sample_cnt = sample_cnt;
690 			base_step_cnt = step_cnt;
691 			if (best_mul == opt_div)
692 				break;
693 		}
694 	}
695 
696 	if (ret)
697 		return -EINVAL;
698 
699 	sample_cnt = base_sample_cnt;
700 	step_cnt = base_step_cnt;
701 
702 	if ((clk_src / (2 * sample_cnt * step_cnt)) > target_speed) {
703 		/* In this case, hardware can't support such
704 		 * low i2c_bus_freq
705 		 */
706 		dev_dbg(i2c->dev, "Unsupported speed (%uhz)\n",	target_speed);
707 		return -EINVAL;
708 	}
709 
710 	*timing_step_cnt = step_cnt - 1;
711 	*timing_sample_cnt = sample_cnt - 1;
712 
713 	return 0;
714 }
715 
716 static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk)
717 {
718 	unsigned int clk_src;
719 	unsigned int step_cnt;
720 	unsigned int sample_cnt;
721 	unsigned int l_step_cnt;
722 	unsigned int l_sample_cnt;
723 	unsigned int target_speed;
724 	unsigned int clk_div;
725 	unsigned int max_clk_div;
726 	int ret;
727 
728 	target_speed = i2c->speed_hz;
729 	parent_clk /= i2c->clk_src_div;
730 
731 	if (i2c->dev_comp->timing_adjust)
732 		max_clk_div = MAX_CLOCK_DIV;
733 	else
734 		max_clk_div = 1;
735 
736 	for (clk_div = 1; clk_div <= max_clk_div; clk_div++) {
737 		clk_src = parent_clk / clk_div;
738 
739 		if (target_speed > I2C_MAX_FAST_MODE_FREQ) {
740 			/* Set master code speed register */
741 			ret = mtk_i2c_calculate_speed(i2c, clk_src,
742 						      I2C_MAX_FAST_MODE_FREQ,
743 						      &l_step_cnt,
744 						      &l_sample_cnt);
745 			if (ret < 0)
746 				continue;
747 
748 			i2c->timing_reg = (l_sample_cnt << 8) | l_step_cnt;
749 
750 			/* Set the high speed mode register */
751 			ret = mtk_i2c_calculate_speed(i2c, clk_src,
752 						      target_speed, &step_cnt,
753 						      &sample_cnt);
754 			if (ret < 0)
755 				continue;
756 
757 			i2c->high_speed_reg = I2C_TIME_DEFAULT_VALUE |
758 					(sample_cnt << 12) | (step_cnt << 8);
759 
760 			if (i2c->dev_comp->ltiming_adjust)
761 				i2c->ltiming_reg =
762 					(l_sample_cnt << 6) | l_step_cnt |
763 					(sample_cnt << 12) | (step_cnt << 9);
764 		} else {
765 			ret = mtk_i2c_calculate_speed(i2c, clk_src,
766 						      target_speed, &l_step_cnt,
767 						      &l_sample_cnt);
768 			if (ret < 0)
769 				continue;
770 
771 			i2c->timing_reg = (l_sample_cnt << 8) | l_step_cnt;
772 
773 			/* Disable the high speed transaction */
774 			i2c->high_speed_reg = I2C_TIME_CLR_VALUE;
775 
776 			if (i2c->dev_comp->ltiming_adjust)
777 				i2c->ltiming_reg =
778 					(l_sample_cnt << 6) | l_step_cnt;
779 		}
780 
781 		break;
782 	}
783 
784 	i2c->ac_timing.inter_clk_div = clk_div - 1;
785 
786 	return 0;
787 }
788 
789 static inline u32 mtk_i2c_set_4g_mode(dma_addr_t addr)
790 {
791 	return (addr & BIT_ULL(32)) ? I2C_DMA_4G_MODE : I2C_DMA_CLR_FLAG;
792 }
793 
794 static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
795 			       int num, int left_num)
796 {
797 	u16 addr_reg;
798 	u16 start_reg;
799 	u16 control_reg;
800 	u16 restart_flag = 0;
801 	u32 reg_4g_mode;
802 	u8 *dma_rd_buf = NULL;
803 	u8 *dma_wr_buf = NULL;
804 	dma_addr_t rpaddr = 0;
805 	dma_addr_t wpaddr = 0;
806 	int ret;
807 
808 	i2c->irq_stat = 0;
809 
810 	if (i2c->auto_restart)
811 		restart_flag = I2C_RS_TRANSFER;
812 
813 	reinit_completion(&i2c->msg_complete);
814 
815 	control_reg = mtk_i2c_readw(i2c, OFFSET_CONTROL) &
816 			~(I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS);
817 	if ((i2c->speed_hz > I2C_MAX_FAST_MODE_FREQ) || (left_num >= 1))
818 		control_reg |= I2C_CONTROL_RS;
819 
820 	if (i2c->op == I2C_MASTER_WRRD)
821 		control_reg |= I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS;
822 
823 	mtk_i2c_writew(i2c, control_reg, OFFSET_CONTROL);
824 
825 	addr_reg = i2c_8bit_addr_from_msg(msgs);
826 	mtk_i2c_writew(i2c, addr_reg, OFFSET_SLAVE_ADDR);
827 
828 	/* Clear interrupt status */
829 	mtk_i2c_writew(i2c, restart_flag | I2C_HS_NACKERR | I2C_ACKERR |
830 			    I2C_ARB_LOST | I2C_TRANSAC_COMP, OFFSET_INTR_STAT);
831 
832 	mtk_i2c_writew(i2c, I2C_FIFO_ADDR_CLR, OFFSET_FIFO_ADDR_CLR);
833 
834 	/* Enable interrupt */
835 	mtk_i2c_writew(i2c, restart_flag | I2C_HS_NACKERR | I2C_ACKERR |
836 			    I2C_ARB_LOST | I2C_TRANSAC_COMP, OFFSET_INTR_MASK);
837 
838 	/* Set transfer and transaction len */
839 	if (i2c->op == I2C_MASTER_WRRD) {
840 		if (i2c->dev_comp->aux_len_reg) {
841 			mtk_i2c_writew(i2c, msgs->len, OFFSET_TRANSFER_LEN);
842 			mtk_i2c_writew(i2c, (msgs + 1)->len,
843 					    OFFSET_TRANSFER_LEN_AUX);
844 		} else {
845 			mtk_i2c_writew(i2c, msgs->len | ((msgs + 1)->len) << 8,
846 					    OFFSET_TRANSFER_LEN);
847 		}
848 		mtk_i2c_writew(i2c, I2C_WRRD_TRANAC_VALUE, OFFSET_TRANSAC_LEN);
849 	} else {
850 		mtk_i2c_writew(i2c, msgs->len, OFFSET_TRANSFER_LEN);
851 		mtk_i2c_writew(i2c, num, OFFSET_TRANSAC_LEN);
852 	}
853 
854 	/* Prepare buffer data to start transfer */
855 	if (i2c->op == I2C_MASTER_RD) {
856 		writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG);
857 		writel(I2C_DMA_CON_RX, i2c->pdmabase + OFFSET_CON);
858 
859 		dma_rd_buf = i2c_get_dma_safe_msg_buf(msgs, 1);
860 		if (!dma_rd_buf)
861 			return -ENOMEM;
862 
863 		rpaddr = dma_map_single(i2c->dev, dma_rd_buf,
864 					msgs->len, DMA_FROM_DEVICE);
865 		if (dma_mapping_error(i2c->dev, rpaddr)) {
866 			i2c_put_dma_safe_msg_buf(dma_rd_buf, msgs, false);
867 
868 			return -ENOMEM;
869 		}
870 
871 		if (i2c->dev_comp->support_33bits) {
872 			reg_4g_mode = mtk_i2c_set_4g_mode(rpaddr);
873 			writel(reg_4g_mode, i2c->pdmabase + OFFSET_RX_4G_MODE);
874 		}
875 
876 		writel((u32)rpaddr, i2c->pdmabase + OFFSET_RX_MEM_ADDR);
877 		writel(msgs->len, i2c->pdmabase + OFFSET_RX_LEN);
878 	} else if (i2c->op == I2C_MASTER_WR) {
879 		writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG);
880 		writel(I2C_DMA_CON_TX, i2c->pdmabase + OFFSET_CON);
881 
882 		dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 1);
883 		if (!dma_wr_buf)
884 			return -ENOMEM;
885 
886 		wpaddr = dma_map_single(i2c->dev, dma_wr_buf,
887 					msgs->len, DMA_TO_DEVICE);
888 		if (dma_mapping_error(i2c->dev, wpaddr)) {
889 			i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, false);
890 
891 			return -ENOMEM;
892 		}
893 
894 		if (i2c->dev_comp->support_33bits) {
895 			reg_4g_mode = mtk_i2c_set_4g_mode(wpaddr);
896 			writel(reg_4g_mode, i2c->pdmabase + OFFSET_TX_4G_MODE);
897 		}
898 
899 		writel((u32)wpaddr, i2c->pdmabase + OFFSET_TX_MEM_ADDR);
900 		writel(msgs->len, i2c->pdmabase + OFFSET_TX_LEN);
901 	} else {
902 		writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_INT_FLAG);
903 		writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_CON);
904 
905 		dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 1);
906 		if (!dma_wr_buf)
907 			return -ENOMEM;
908 
909 		wpaddr = dma_map_single(i2c->dev, dma_wr_buf,
910 					msgs->len, DMA_TO_DEVICE);
911 		if (dma_mapping_error(i2c->dev, wpaddr)) {
912 			i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, false);
913 
914 			return -ENOMEM;
915 		}
916 
917 		dma_rd_buf = i2c_get_dma_safe_msg_buf((msgs + 1), 1);
918 		if (!dma_rd_buf) {
919 			dma_unmap_single(i2c->dev, wpaddr,
920 					 msgs->len, DMA_TO_DEVICE);
921 
922 			i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, false);
923 
924 			return -ENOMEM;
925 		}
926 
927 		rpaddr = dma_map_single(i2c->dev, dma_rd_buf,
928 					(msgs + 1)->len,
929 					DMA_FROM_DEVICE);
930 		if (dma_mapping_error(i2c->dev, rpaddr)) {
931 			dma_unmap_single(i2c->dev, wpaddr,
932 					 msgs->len, DMA_TO_DEVICE);
933 
934 			i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, false);
935 			i2c_put_dma_safe_msg_buf(dma_rd_buf, (msgs + 1), false);
936 
937 			return -ENOMEM;
938 		}
939 
940 		if (i2c->dev_comp->support_33bits) {
941 			reg_4g_mode = mtk_i2c_set_4g_mode(wpaddr);
942 			writel(reg_4g_mode, i2c->pdmabase + OFFSET_TX_4G_MODE);
943 
944 			reg_4g_mode = mtk_i2c_set_4g_mode(rpaddr);
945 			writel(reg_4g_mode, i2c->pdmabase + OFFSET_RX_4G_MODE);
946 		}
947 
948 		writel((u32)wpaddr, i2c->pdmabase + OFFSET_TX_MEM_ADDR);
949 		writel((u32)rpaddr, i2c->pdmabase + OFFSET_RX_MEM_ADDR);
950 		writel(msgs->len, i2c->pdmabase + OFFSET_TX_LEN);
951 		writel((msgs + 1)->len, i2c->pdmabase + OFFSET_RX_LEN);
952 	}
953 
954 	writel(I2C_DMA_START_EN, i2c->pdmabase + OFFSET_EN);
955 
956 	if (!i2c->auto_restart) {
957 		start_reg = I2C_TRANSAC_START;
958 	} else {
959 		start_reg = I2C_TRANSAC_START | I2C_RS_MUL_TRIG;
960 		if (left_num >= 1)
961 			start_reg |= I2C_RS_MUL_CNFG;
962 	}
963 	mtk_i2c_writew(i2c, start_reg, OFFSET_START);
964 
965 	ret = wait_for_completion_timeout(&i2c->msg_complete,
966 					  i2c->adap.timeout);
967 
968 	/* Clear interrupt mask */
969 	mtk_i2c_writew(i2c, ~(restart_flag | I2C_HS_NACKERR | I2C_ACKERR |
970 			    I2C_ARB_LOST | I2C_TRANSAC_COMP), OFFSET_INTR_MASK);
971 
972 	if (i2c->op == I2C_MASTER_WR) {
973 		dma_unmap_single(i2c->dev, wpaddr,
974 				 msgs->len, DMA_TO_DEVICE);
975 
976 		i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, true);
977 	} else if (i2c->op == I2C_MASTER_RD) {
978 		dma_unmap_single(i2c->dev, rpaddr,
979 				 msgs->len, DMA_FROM_DEVICE);
980 
981 		i2c_put_dma_safe_msg_buf(dma_rd_buf, msgs, true);
982 	} else {
983 		dma_unmap_single(i2c->dev, wpaddr, msgs->len,
984 				 DMA_TO_DEVICE);
985 		dma_unmap_single(i2c->dev, rpaddr, (msgs + 1)->len,
986 				 DMA_FROM_DEVICE);
987 
988 		i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, true);
989 		i2c_put_dma_safe_msg_buf(dma_rd_buf, (msgs + 1), true);
990 	}
991 
992 	if (ret == 0) {
993 		dev_dbg(i2c->dev, "addr: %x, transfer timeout\n", msgs->addr);
994 		mtk_i2c_init_hw(i2c);
995 		return -ETIMEDOUT;
996 	}
997 
998 	if (i2c->irq_stat & (I2C_HS_NACKERR | I2C_ACKERR)) {
999 		dev_dbg(i2c->dev, "addr: %x, transfer ACK error\n", msgs->addr);
1000 		mtk_i2c_init_hw(i2c);
1001 		return -ENXIO;
1002 	}
1003 
1004 	return 0;
1005 }
1006 
1007 static int mtk_i2c_transfer(struct i2c_adapter *adap,
1008 			    struct i2c_msg msgs[], int num)
1009 {
1010 	int ret;
1011 	int left_num = num;
1012 	struct mtk_i2c *i2c = i2c_get_adapdata(adap);
1013 
1014 	ret = mtk_i2c_clock_enable(i2c);
1015 	if (ret)
1016 		return ret;
1017 
1018 	i2c->auto_restart = i2c->dev_comp->auto_restart;
1019 
1020 	/* checking if we can skip restart and optimize using WRRD mode */
1021 	if (i2c->auto_restart && num == 2) {
1022 		if (!(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD) &&
1023 		    msgs[0].addr == msgs[1].addr) {
1024 			i2c->auto_restart = 0;
1025 		}
1026 	}
1027 
1028 	if (i2c->auto_restart && num >= 2 && i2c->speed_hz > I2C_MAX_FAST_MODE_FREQ)
1029 		/* ignore the first restart irq after the master code,
1030 		 * otherwise the first transfer will be discarded.
1031 		 */
1032 		i2c->ignore_restart_irq = true;
1033 	else
1034 		i2c->ignore_restart_irq = false;
1035 
1036 	while (left_num--) {
1037 		if (!msgs->buf) {
1038 			dev_dbg(i2c->dev, "data buffer is NULL.\n");
1039 			ret = -EINVAL;
1040 			goto err_exit;
1041 		}
1042 
1043 		if (msgs->flags & I2C_M_RD)
1044 			i2c->op = I2C_MASTER_RD;
1045 		else
1046 			i2c->op = I2C_MASTER_WR;
1047 
1048 		if (!i2c->auto_restart) {
1049 			if (num > 1) {
1050 				/* combined two messages into one transaction */
1051 				i2c->op = I2C_MASTER_WRRD;
1052 				left_num--;
1053 			}
1054 		}
1055 
1056 		/* always use DMA mode. */
1057 		ret = mtk_i2c_do_transfer(i2c, msgs, num, left_num);
1058 		if (ret < 0)
1059 			goto err_exit;
1060 
1061 		msgs++;
1062 	}
1063 	/* the return value is number of executed messages */
1064 	ret = num;
1065 
1066 err_exit:
1067 	mtk_i2c_clock_disable(i2c);
1068 	return ret;
1069 }
1070 
1071 static irqreturn_t mtk_i2c_irq(int irqno, void *dev_id)
1072 {
1073 	struct mtk_i2c *i2c = dev_id;
1074 	u16 restart_flag = 0;
1075 	u16 intr_stat;
1076 
1077 	if (i2c->auto_restart)
1078 		restart_flag = I2C_RS_TRANSFER;
1079 
1080 	intr_stat = mtk_i2c_readw(i2c, OFFSET_INTR_STAT);
1081 	mtk_i2c_writew(i2c, intr_stat, OFFSET_INTR_STAT);
1082 
1083 	/*
1084 	 * when occurs ack error, i2c controller generate two interrupts
1085 	 * first is the ack error interrupt, then the complete interrupt
1086 	 * i2c->irq_stat need keep the two interrupt value.
1087 	 */
1088 	i2c->irq_stat |= intr_stat;
1089 
1090 	if (i2c->ignore_restart_irq && (i2c->irq_stat & restart_flag)) {
1091 		i2c->ignore_restart_irq = false;
1092 		i2c->irq_stat = 0;
1093 		mtk_i2c_writew(i2c, I2C_RS_MUL_CNFG | I2C_RS_MUL_TRIG |
1094 				    I2C_TRANSAC_START, OFFSET_START);
1095 	} else {
1096 		if (i2c->irq_stat & (I2C_TRANSAC_COMP | restart_flag))
1097 			complete(&i2c->msg_complete);
1098 	}
1099 
1100 	return IRQ_HANDLED;
1101 }
1102 
1103 static u32 mtk_i2c_functionality(struct i2c_adapter *adap)
1104 {
1105 	if (i2c_check_quirks(adap, I2C_AQ_NO_ZERO_LEN))
1106 		return I2C_FUNC_I2C |
1107 			(I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
1108 	else
1109 		return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
1110 }
1111 
1112 static const struct i2c_algorithm mtk_i2c_algorithm = {
1113 	.master_xfer = mtk_i2c_transfer,
1114 	.functionality = mtk_i2c_functionality,
1115 };
1116 
1117 static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c)
1118 {
1119 	int ret;
1120 
1121 	ret = of_property_read_u32(np, "clock-frequency", &i2c->speed_hz);
1122 	if (ret < 0)
1123 		i2c->speed_hz = I2C_MAX_STANDARD_MODE_FREQ;
1124 
1125 	ret = of_property_read_u32(np, "clock-div", &i2c->clk_src_div);
1126 	if (ret < 0)
1127 		return ret;
1128 
1129 	if (i2c->clk_src_div == 0)
1130 		return -EINVAL;
1131 
1132 	i2c->have_pmic = of_property_read_bool(np, "mediatek,have-pmic");
1133 	i2c->use_push_pull =
1134 		of_property_read_bool(np, "mediatek,use-push-pull");
1135 
1136 	return 0;
1137 }
1138 
1139 static int mtk_i2c_probe(struct platform_device *pdev)
1140 {
1141 	int ret = 0;
1142 	struct mtk_i2c *i2c;
1143 	struct clk *clk;
1144 	struct resource *res;
1145 	int irq;
1146 
1147 	i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
1148 	if (!i2c)
1149 		return -ENOMEM;
1150 
1151 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1152 	i2c->base = devm_ioremap_resource(&pdev->dev, res);
1153 	if (IS_ERR(i2c->base))
1154 		return PTR_ERR(i2c->base);
1155 
1156 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1157 	i2c->pdmabase = devm_ioremap_resource(&pdev->dev, res);
1158 	if (IS_ERR(i2c->pdmabase))
1159 		return PTR_ERR(i2c->pdmabase);
1160 
1161 	irq = platform_get_irq(pdev, 0);
1162 	if (irq <= 0)
1163 		return irq;
1164 
1165 	init_completion(&i2c->msg_complete);
1166 
1167 	i2c->dev_comp = of_device_get_match_data(&pdev->dev);
1168 	i2c->adap.dev.of_node = pdev->dev.of_node;
1169 	i2c->dev = &pdev->dev;
1170 	i2c->adap.dev.parent = &pdev->dev;
1171 	i2c->adap.owner = THIS_MODULE;
1172 	i2c->adap.algo = &mtk_i2c_algorithm;
1173 	i2c->adap.quirks = i2c->dev_comp->quirks;
1174 	i2c->adap.timeout = 2 * HZ;
1175 	i2c->adap.retries = 1;
1176 
1177 	ret = mtk_i2c_parse_dt(pdev->dev.of_node, i2c);
1178 	if (ret)
1179 		return -EINVAL;
1180 
1181 	if (i2c->have_pmic && !i2c->dev_comp->pmic_i2c)
1182 		return -EINVAL;
1183 
1184 	i2c->clk_main = devm_clk_get(&pdev->dev, "main");
1185 	if (IS_ERR(i2c->clk_main)) {
1186 		dev_err(&pdev->dev, "cannot get main clock\n");
1187 		return PTR_ERR(i2c->clk_main);
1188 	}
1189 
1190 	i2c->clk_dma = devm_clk_get(&pdev->dev, "dma");
1191 	if (IS_ERR(i2c->clk_dma)) {
1192 		dev_err(&pdev->dev, "cannot get dma clock\n");
1193 		return PTR_ERR(i2c->clk_dma);
1194 	}
1195 
1196 	i2c->clk_arb = devm_clk_get(&pdev->dev, "arb");
1197 	if (IS_ERR(i2c->clk_arb))
1198 		i2c->clk_arb = NULL;
1199 
1200 	clk = i2c->clk_main;
1201 	if (i2c->have_pmic) {
1202 		i2c->clk_pmic = devm_clk_get(&pdev->dev, "pmic");
1203 		if (IS_ERR(i2c->clk_pmic)) {
1204 			dev_err(&pdev->dev, "cannot get pmic clock\n");
1205 			return PTR_ERR(i2c->clk_pmic);
1206 		}
1207 		clk = i2c->clk_pmic;
1208 	}
1209 
1210 	strlcpy(i2c->adap.name, I2C_DRV_NAME, sizeof(i2c->adap.name));
1211 
1212 	ret = mtk_i2c_set_speed(i2c, clk_get_rate(clk));
1213 	if (ret) {
1214 		dev_err(&pdev->dev, "Failed to set the speed.\n");
1215 		return -EINVAL;
1216 	}
1217 
1218 	if (i2c->dev_comp->support_33bits) {
1219 		ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(33));
1220 		if (ret) {
1221 			dev_err(&pdev->dev, "dma_set_mask return error.\n");
1222 			return ret;
1223 		}
1224 	}
1225 
1226 	ret = mtk_i2c_clock_enable(i2c);
1227 	if (ret) {
1228 		dev_err(&pdev->dev, "clock enable failed!\n");
1229 		return ret;
1230 	}
1231 	mtk_i2c_init_hw(i2c);
1232 	mtk_i2c_clock_disable(i2c);
1233 
1234 	ret = devm_request_irq(&pdev->dev, irq, mtk_i2c_irq,
1235 			       IRQF_TRIGGER_NONE, I2C_DRV_NAME, i2c);
1236 	if (ret < 0) {
1237 		dev_err(&pdev->dev,
1238 			"Request I2C IRQ %d fail\n", irq);
1239 		return ret;
1240 	}
1241 
1242 	i2c_set_adapdata(&i2c->adap, i2c);
1243 	ret = i2c_add_adapter(&i2c->adap);
1244 	if (ret)
1245 		return ret;
1246 
1247 	platform_set_drvdata(pdev, i2c);
1248 
1249 	return 0;
1250 }
1251 
1252 static int mtk_i2c_remove(struct platform_device *pdev)
1253 {
1254 	struct mtk_i2c *i2c = platform_get_drvdata(pdev);
1255 
1256 	i2c_del_adapter(&i2c->adap);
1257 
1258 	return 0;
1259 }
1260 
1261 #ifdef CONFIG_PM_SLEEP
1262 static int mtk_i2c_resume(struct device *dev)
1263 {
1264 	int ret;
1265 	struct mtk_i2c *i2c = dev_get_drvdata(dev);
1266 
1267 	ret = mtk_i2c_clock_enable(i2c);
1268 	if (ret) {
1269 		dev_err(dev, "clock enable failed!\n");
1270 		return ret;
1271 	}
1272 
1273 	mtk_i2c_init_hw(i2c);
1274 
1275 	mtk_i2c_clock_disable(i2c);
1276 
1277 	return 0;
1278 }
1279 #endif
1280 
1281 static const struct dev_pm_ops mtk_i2c_pm = {
1282 	SET_SYSTEM_SLEEP_PM_OPS(NULL, mtk_i2c_resume)
1283 };
1284 
1285 static struct platform_driver mtk_i2c_driver = {
1286 	.probe = mtk_i2c_probe,
1287 	.remove = mtk_i2c_remove,
1288 	.driver = {
1289 		.name = I2C_DRV_NAME,
1290 		.pm = &mtk_i2c_pm,
1291 		.of_match_table = of_match_ptr(mtk_i2c_of_match),
1292 	},
1293 };
1294 
1295 module_platform_driver(mtk_i2c_driver);
1296 
1297 MODULE_LICENSE("GPL v2");
1298 MODULE_DESCRIPTION("MediaTek I2C Bus Driver");
1299 MODULE_AUTHOR("Xudong Chen <xudong.chen@mediatek.com>");
1300