xref: /linux/drivers/i2c/busses/i2c-hisi.c (revision 47096fc3d064a07c0842f748b99ebf01be120f2b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * HiSilicon I2C Controller Driver for Kunpeng SoC
4  *
5  * Copyright (c) 2021 HiSilicon Technologies Co., Ltd.
6  */
7 
8 #include <linux/bits.h>
9 #include <linux/bitfield.h>
10 #include <linux/clk.h>
11 #include <linux/completion.h>
12 #include <linux/i2c.h>
13 #include <linux/interrupt.h>
14 #include <linux/io.h>
15 #include <linux/module.h>
16 #include <linux/platform_device.h>
17 #include <linux/property.h>
18 #include <linux/units.h>
19 
20 #define HISI_I2C_FRAME_CTRL		0x0000
21 #define   HISI_I2C_FRAME_CTRL_SPEED_MODE	GENMASK(1, 0)
22 #define   HISI_I2C_FRAME_CTRL_ADDR_TEN	BIT(2)
23 #define HISI_I2C_SLV_ADDR		0x0004
24 #define   HISI_I2C_SLV_ADDR_VAL		GENMASK(9, 0)
25 #define   HISI_I2C_SLV_ADDR_GC_S_MODE	BIT(10)
26 #define   HISI_I2C_SLV_ADDR_GC_S_EN	BIT(11)
27 #define HISI_I2C_CMD_TXDATA		0x0008
28 #define   HISI_I2C_CMD_TXDATA_DATA	GENMASK(7, 0)
29 #define   HISI_I2C_CMD_TXDATA_RW	BIT(8)
30 #define   HISI_I2C_CMD_TXDATA_P_EN	BIT(9)
31 #define   HISI_I2C_CMD_TXDATA_SR_EN	BIT(10)
32 #define HISI_I2C_RXDATA			0x000c
33 #define   HISI_I2C_RXDATA_DATA		GENMASK(7, 0)
34 #define HISI_I2C_SS_SCL_HCNT		0x0010
35 #define HISI_I2C_SS_SCL_LCNT		0x0014
36 #define HISI_I2C_FS_SCL_HCNT		0x0018
37 #define HISI_I2C_FS_SCL_LCNT		0x001c
38 #define HISI_I2C_HS_SCL_HCNT		0x0020
39 #define HISI_I2C_HS_SCL_LCNT		0x0024
40 #define HISI_I2C_FIFO_CTRL		0x0028
41 #define   HISI_I2C_FIFO_RX_CLR		BIT(0)
42 #define   HISI_I2C_FIFO_TX_CLR		BIT(1)
43 #define   HISI_I2C_FIFO_RX_AF_THRESH	GENMASK(7, 2)
44 #define   HISI_I2C_FIFO_TX_AE_THRESH	GENMASK(13, 8)
45 #define HISI_I2C_FIFO_STATE		0x002c
46 #define   HISI_I2C_FIFO_STATE_RX_RERR	BIT(0)
47 #define   HISI_I2C_FIFO_STATE_RX_WERR	BIT(1)
48 #define   HISI_I2C_FIFO_STATE_RX_EMPTY	BIT(3)
49 #define   HISI_I2C_FIFO_STATE_TX_RERR	BIT(6)
50 #define   HISI_I2C_FIFO_STATE_TX_WERR	BIT(7)
51 #define   HISI_I2C_FIFO_STATE_TX_FULL	BIT(11)
52 #define HISI_I2C_SDA_HOLD		0x0030
53 #define   HISI_I2C_SDA_HOLD_TX		GENMASK(15, 0)
54 #define   HISI_I2C_SDA_HOLD_RX		GENMASK(23, 16)
55 #define HISI_I2C_FS_SPK_LEN		0x0038
56 #define   HISI_I2C_FS_SPK_LEN_CNT	GENMASK(7, 0)
57 #define HISI_I2C_HS_SPK_LEN		0x003c
58 #define   HISI_I2C_HS_SPK_LEN_CNT	GENMASK(7, 0)
59 #define HISI_I2C_TX_INT_CLR		0x0040
60 #define   HISI_I2C_TX_AEMPTY_INT		BIT(0)
61 #define HISI_I2C_INT_MSTAT		0x0044
62 #define HISI_I2C_INT_CLR		0x0048
63 #define HISI_I2C_INT_MASK		0x004C
64 #define HISI_I2C_TRANS_STATE		0x0050
65 #define HISI_I2C_TRANS_ERR		0x0054
66 #define HISI_I2C_VERSION		0x0058
67 
68 #define HISI_I2C_INT_ALL	GENMASK(4, 0)
69 #define HISI_I2C_INT_TRANS_CPLT	BIT(0)
70 #define HISI_I2C_INT_TRANS_ERR	BIT(1)
71 #define HISI_I2C_INT_FIFO_ERR	BIT(2)
72 #define HISI_I2C_INT_RX_FULL	BIT(3)
73 #define HISI_I2C_INT_TX_EMPTY	BIT(4)
74 #define HISI_I2C_INT_ERR \
75 	(HISI_I2C_INT_TRANS_ERR | HISI_I2C_INT_FIFO_ERR)
76 
77 #define HISI_I2C_STD_SPEED_MODE		0
78 #define HISI_I2C_FAST_SPEED_MODE	1
79 #define HISI_I2C_HIGH_SPEED_MODE	2
80 
81 #define HISI_I2C_TX_FIFO_DEPTH		64
82 #define HISI_I2C_RX_FIFO_DEPTH		64
83 #define HISI_I2C_TX_F_AE_THRESH		1
84 #define HISI_I2C_RX_F_AF_THRESH		60
85 
86 #define NSEC_TO_CYCLES(ns, clk_rate_khz) \
87 	DIV_ROUND_UP_ULL((clk_rate_khz) * (ns), NSEC_PER_MSEC)
88 
89 struct hisi_i2c_controller {
90 	struct i2c_adapter adapter;
91 	void __iomem *iobase;
92 	struct device *dev;
93 	struct clk *clk;
94 	int irq;
95 
96 	/* Intermediates for recording the transfer process */
97 	struct completion *completion;
98 	struct i2c_msg *msgs;
99 	int msg_num;
100 	int msg_tx_idx;
101 	int buf_tx_idx;
102 	int msg_rx_idx;
103 	int buf_rx_idx;
104 	u16 tar_addr;
105 	u32 xfer_err;
106 
107 	/* I2C bus configuration */
108 	struct i2c_timings t;
109 	u32 clk_rate_khz;
110 	u32 spk_len;
111 };
112 
hisi_i2c_enable_int(struct hisi_i2c_controller * ctlr,u32 mask)113 static void hisi_i2c_enable_int(struct hisi_i2c_controller *ctlr, u32 mask)
114 {
115 	writel_relaxed(mask, ctlr->iobase + HISI_I2C_INT_MASK);
116 }
117 
hisi_i2c_disable_int(struct hisi_i2c_controller * ctlr,u32 mask)118 static void hisi_i2c_disable_int(struct hisi_i2c_controller *ctlr, u32 mask)
119 {
120 	writel_relaxed((~mask) & HISI_I2C_INT_ALL, ctlr->iobase + HISI_I2C_INT_MASK);
121 }
122 
hisi_i2c_clear_int(struct hisi_i2c_controller * ctlr,u32 mask)123 static void hisi_i2c_clear_int(struct hisi_i2c_controller *ctlr, u32 mask)
124 {
125 	writel_relaxed(mask, ctlr->iobase + HISI_I2C_INT_CLR);
126 }
127 
hisi_i2c_clear_tx_int(struct hisi_i2c_controller * ctlr,u32 mask)128 static void hisi_i2c_clear_tx_int(struct hisi_i2c_controller *ctlr, u32 mask)
129 {
130 	writel_relaxed(mask, ctlr->iobase + HISI_I2C_TX_INT_CLR);
131 }
132 
hisi_i2c_handle_errors(struct hisi_i2c_controller * ctlr)133 static void hisi_i2c_handle_errors(struct hisi_i2c_controller *ctlr)
134 {
135 	u32 int_err = ctlr->xfer_err, reg;
136 
137 	if (int_err & HISI_I2C_INT_FIFO_ERR) {
138 		reg = readl(ctlr->iobase + HISI_I2C_FIFO_STATE);
139 
140 		if (reg & HISI_I2C_FIFO_STATE_RX_RERR)
141 			dev_err(ctlr->dev, "rx fifo error read\n");
142 
143 		if (reg & HISI_I2C_FIFO_STATE_RX_WERR)
144 			dev_err(ctlr->dev, "rx fifo error write\n");
145 
146 		if (reg & HISI_I2C_FIFO_STATE_TX_RERR)
147 			dev_err(ctlr->dev, "tx fifo error read\n");
148 
149 		if (reg & HISI_I2C_FIFO_STATE_TX_WERR)
150 			dev_err(ctlr->dev, "tx fifo error write\n");
151 	}
152 }
153 
hisi_i2c_start_xfer(struct hisi_i2c_controller * ctlr)154 static int hisi_i2c_start_xfer(struct hisi_i2c_controller *ctlr)
155 {
156 	struct i2c_msg *msg = ctlr->msgs;
157 	u32 reg;
158 
159 	reg = readl(ctlr->iobase + HISI_I2C_FRAME_CTRL);
160 	reg &= ~HISI_I2C_FRAME_CTRL_ADDR_TEN;
161 	if (msg->flags & I2C_M_TEN)
162 		reg |= HISI_I2C_FRAME_CTRL_ADDR_TEN;
163 	writel(reg, ctlr->iobase + HISI_I2C_FRAME_CTRL);
164 
165 	reg = readl(ctlr->iobase + HISI_I2C_SLV_ADDR);
166 	reg &= ~HISI_I2C_SLV_ADDR_VAL;
167 	reg |= FIELD_PREP(HISI_I2C_SLV_ADDR_VAL, msg->addr);
168 	writel(reg, ctlr->iobase + HISI_I2C_SLV_ADDR);
169 
170 	reg = readl(ctlr->iobase + HISI_I2C_FIFO_CTRL);
171 	reg |= HISI_I2C_FIFO_RX_CLR | HISI_I2C_FIFO_TX_CLR;
172 	writel(reg, ctlr->iobase + HISI_I2C_FIFO_CTRL);
173 	reg &= ~(HISI_I2C_FIFO_RX_CLR | HISI_I2C_FIFO_TX_CLR);
174 	writel(reg, ctlr->iobase + HISI_I2C_FIFO_CTRL);
175 
176 	hisi_i2c_clear_int(ctlr, HISI_I2C_INT_ALL);
177 	hisi_i2c_clear_tx_int(ctlr, HISI_I2C_TX_AEMPTY_INT);
178 	hisi_i2c_enable_int(ctlr, HISI_I2C_INT_ALL);
179 
180 	return 0;
181 }
182 
hisi_i2c_reset_xfer(struct hisi_i2c_controller * ctlr)183 static void hisi_i2c_reset_xfer(struct hisi_i2c_controller *ctlr)
184 {
185 	ctlr->msg_num = 0;
186 	ctlr->xfer_err = 0;
187 	ctlr->msg_tx_idx = 0;
188 	ctlr->msg_rx_idx = 0;
189 	ctlr->buf_tx_idx = 0;
190 	ctlr->buf_rx_idx = 0;
191 }
192 
193 /*
194  * Initialize the transfer information and start the I2C bus transfer.
195  * We only configure the transfer and do some pre/post works here, and
196  * wait for the transfer done. The major transfer process is performed
197  * in the IRQ handler.
198  */
hisi_i2c_xfer(struct i2c_adapter * adap,struct i2c_msg * msgs,int num)199 static int hisi_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
200 			 int num)
201 {
202 	struct hisi_i2c_controller *ctlr = i2c_get_adapdata(adap);
203 	DECLARE_COMPLETION_ONSTACK(done);
204 	int ret = num;
205 
206 	hisi_i2c_reset_xfer(ctlr);
207 	ctlr->completion = &done;
208 	ctlr->msg_num = num;
209 	ctlr->msgs = msgs;
210 
211 	hisi_i2c_start_xfer(ctlr);
212 
213 	if (!wait_for_completion_timeout(ctlr->completion, adap->timeout)) {
214 		hisi_i2c_disable_int(ctlr, HISI_I2C_INT_ALL);
215 		synchronize_irq(ctlr->irq);
216 		i2c_recover_bus(&ctlr->adapter);
217 		dev_err(ctlr->dev, "bus transfer timeout\n");
218 		ret = -EIO;
219 	}
220 
221 	if (ctlr->xfer_err) {
222 		hisi_i2c_handle_errors(ctlr);
223 		ret = -EIO;
224 	}
225 
226 	hisi_i2c_reset_xfer(ctlr);
227 	ctlr->completion = NULL;
228 
229 	return ret;
230 }
231 
hisi_i2c_functionality(struct i2c_adapter * adap)232 static u32 hisi_i2c_functionality(struct i2c_adapter *adap)
233 {
234 	return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL;
235 }
236 
237 static const struct i2c_algorithm hisi_i2c_algo = {
238 	.xfer = hisi_i2c_xfer,
239 	.functionality = hisi_i2c_functionality,
240 };
241 
hisi_i2c_read_rx_fifo(struct hisi_i2c_controller * ctlr)242 static int hisi_i2c_read_rx_fifo(struct hisi_i2c_controller *ctlr)
243 {
244 	struct i2c_msg *cur_msg;
245 	u32 fifo_state;
246 
247 	while (ctlr->msg_rx_idx < ctlr->msg_num) {
248 		cur_msg = ctlr->msgs + ctlr->msg_rx_idx;
249 
250 		if (!(cur_msg->flags & I2C_M_RD)) {
251 			ctlr->msg_rx_idx++;
252 			continue;
253 		}
254 
255 		fifo_state = readl(ctlr->iobase + HISI_I2C_FIFO_STATE);
256 		while (!(fifo_state & HISI_I2C_FIFO_STATE_RX_EMPTY) &&
257 		       ctlr->buf_rx_idx < cur_msg->len) {
258 			cur_msg->buf[ctlr->buf_rx_idx++] = readl(ctlr->iobase + HISI_I2C_RXDATA);
259 			fifo_state = readl(ctlr->iobase + HISI_I2C_FIFO_STATE);
260 		}
261 
262 		if (ctlr->buf_rx_idx == cur_msg->len) {
263 			ctlr->buf_rx_idx = 0;
264 			ctlr->msg_rx_idx++;
265 		}
266 
267 		if (fifo_state & HISI_I2C_FIFO_STATE_RX_EMPTY)
268 			break;
269 	}
270 
271 	return 0;
272 }
273 
hisi_i2c_xfer_msg(struct hisi_i2c_controller * ctlr)274 static void hisi_i2c_xfer_msg(struct hisi_i2c_controller *ctlr)
275 {
276 	int max_write = HISI_I2C_TX_FIFO_DEPTH - HISI_I2C_TX_F_AE_THRESH;
277 	bool need_restart = false, last_msg;
278 	struct i2c_msg *cur_msg;
279 	u32 cmd, fifo_state;
280 
281 	while (ctlr->msg_tx_idx < ctlr->msg_num) {
282 		cur_msg = ctlr->msgs + ctlr->msg_tx_idx;
283 		last_msg = (ctlr->msg_tx_idx == ctlr->msg_num - 1);
284 
285 		/* Signal the SR bit when we start transferring a new message */
286 		if (ctlr->msg_tx_idx && !ctlr->buf_tx_idx)
287 			need_restart = true;
288 
289 		fifo_state = readl(ctlr->iobase + HISI_I2C_FIFO_STATE);
290 		while (!(fifo_state & HISI_I2C_FIFO_STATE_TX_FULL) &&
291 		       ctlr->buf_tx_idx < cur_msg->len && max_write) {
292 			cmd = 0;
293 
294 			if (need_restart) {
295 				cmd |= HISI_I2C_CMD_TXDATA_SR_EN;
296 				need_restart = false;
297 			}
298 
299 			/* Signal the STOP bit at the last frame of the last message */
300 			if (ctlr->buf_tx_idx == cur_msg->len - 1 && last_msg)
301 				cmd |= HISI_I2C_CMD_TXDATA_P_EN;
302 
303 			if (cur_msg->flags & I2C_M_RD)
304 				cmd |= HISI_I2C_CMD_TXDATA_RW;
305 			else
306 				cmd |= FIELD_PREP(HISI_I2C_CMD_TXDATA_DATA,
307 						  cur_msg->buf[ctlr->buf_tx_idx]);
308 
309 			writel(cmd, ctlr->iobase + HISI_I2C_CMD_TXDATA);
310 			ctlr->buf_tx_idx++;
311 			max_write--;
312 
313 			fifo_state = readl(ctlr->iobase + HISI_I2C_FIFO_STATE);
314 		}
315 
316 		/* Update the transfer index after per message transfer is done. */
317 		if (ctlr->buf_tx_idx == cur_msg->len) {
318 			ctlr->buf_tx_idx = 0;
319 			ctlr->msg_tx_idx++;
320 		}
321 
322 		if ((fifo_state & HISI_I2C_FIFO_STATE_TX_FULL) ||
323 		    max_write == 0)
324 			break;
325 	}
326 
327 	/*
328 	 * Disable the TX_EMPTY interrupt after finishing all the messages to
329 	 * avoid overwhelming the CPU.
330 	 */
331 	if (ctlr->msg_tx_idx == ctlr->msg_num)
332 		hisi_i2c_disable_int(ctlr, HISI_I2C_INT_TX_EMPTY);
333 
334 	hisi_i2c_clear_tx_int(ctlr, HISI_I2C_TX_AEMPTY_INT);
335 }
336 
hisi_i2c_irq(int irq,void * context)337 static irqreturn_t hisi_i2c_irq(int irq, void *context)
338 {
339 	struct hisi_i2c_controller *ctlr = context;
340 	u32 int_stat;
341 
342 	/*
343 	 * Don't handle the interrupt if cltr->completion is NULL. We may
344 	 * reach here because the interrupt is spurious or the transfer is
345 	 * started by another port (e.g. firmware) rather than us.
346 	 */
347 	if (!ctlr->completion)
348 		return IRQ_NONE;
349 
350 	int_stat = readl(ctlr->iobase + HISI_I2C_INT_MSTAT);
351 	hisi_i2c_clear_int(ctlr, int_stat);
352 	if (!(int_stat & HISI_I2C_INT_ALL))
353 		return IRQ_NONE;
354 
355 	if (int_stat & HISI_I2C_INT_TX_EMPTY)
356 		hisi_i2c_xfer_msg(ctlr);
357 
358 	if (int_stat & HISI_I2C_INT_ERR) {
359 		ctlr->xfer_err = int_stat;
360 		goto out;
361 	}
362 
363 	/* Drain the rx fifo before finish the transfer */
364 	if (int_stat & (HISI_I2C_INT_TRANS_CPLT | HISI_I2C_INT_RX_FULL))
365 		hisi_i2c_read_rx_fifo(ctlr);
366 
367 out:
368 	/*
369 	 * Only use TRANS_CPLT to indicate the completion. On error cases we'll
370 	 * get two interrupts, INT_ERR first then TRANS_CPLT.
371 	 */
372 	if (int_stat & HISI_I2C_INT_TRANS_CPLT) {
373 		hisi_i2c_disable_int(ctlr, HISI_I2C_INT_ALL);
374 		hisi_i2c_clear_int(ctlr, HISI_I2C_INT_ALL);
375 		hisi_i2c_clear_tx_int(ctlr, HISI_I2C_TX_AEMPTY_INT);
376 		complete(ctlr->completion);
377 	}
378 
379 	return IRQ_HANDLED;
380 }
381 
382 /*
383  * Helper function for calculating and configuring the HIGH and LOW
384  * periods of SCL clock. The caller will pass the ratio of the
385  * counts (divide / divisor) according to the target speed mode,
386  * and the target registers.
387  */
hisi_i2c_set_scl(struct hisi_i2c_controller * ctlr,u32 divide,u32 divisor,u32 reg_hcnt,u32 reg_lcnt)388 static void hisi_i2c_set_scl(struct hisi_i2c_controller *ctlr,
389 			     u32 divide, u32 divisor,
390 			     u32 reg_hcnt, u32 reg_lcnt)
391 {
392 	u32 total_cnt, t_scl_hcnt, t_scl_lcnt, scl_fall_cnt, scl_rise_cnt;
393 	u32 scl_hcnt, scl_lcnt;
394 
395 	/* Total SCL clock cycles per speed period */
396 	total_cnt = DIV_ROUND_UP_ULL(ctlr->clk_rate_khz * HZ_PER_KHZ, ctlr->t.bus_freq_hz);
397 	/* Total HIGH level SCL clock cycles including edges */
398 	t_scl_hcnt = DIV_ROUND_UP_ULL(total_cnt * divide, divisor);
399 	/* Total LOW level SCL clock cycles including edges */
400 	t_scl_lcnt = total_cnt - t_scl_hcnt;
401 	/* Fall edge SCL clock cycles */
402 	scl_fall_cnt = NSEC_TO_CYCLES(ctlr->t.scl_fall_ns, ctlr->clk_rate_khz);
403 	/* Rise edge SCL clock cycles */
404 	scl_rise_cnt = NSEC_TO_CYCLES(ctlr->t.scl_rise_ns, ctlr->clk_rate_khz);
405 
406 	/* Calculated HIGH and LOW periods of SCL clock */
407 	scl_hcnt = t_scl_hcnt - ctlr->spk_len - 7 - scl_fall_cnt;
408 	scl_lcnt = t_scl_lcnt - 1 - scl_rise_cnt;
409 
410 	writel(scl_hcnt, ctlr->iobase + reg_hcnt);
411 	writel(scl_lcnt, ctlr->iobase + reg_lcnt);
412 }
413 
hisi_i2c_configure_bus(struct hisi_i2c_controller * ctlr)414 static void hisi_i2c_configure_bus(struct hisi_i2c_controller *ctlr)
415 {
416 	u32 reg, sda_hold_cnt, speed_mode;
417 
418 	i2c_parse_fw_timings(ctlr->dev, &ctlr->t, true);
419 	ctlr->spk_len = NSEC_TO_CYCLES(ctlr->t.digital_filter_width_ns, ctlr->clk_rate_khz);
420 
421 	switch (ctlr->t.bus_freq_hz) {
422 	case I2C_MAX_FAST_MODE_FREQ:
423 		speed_mode = HISI_I2C_FAST_SPEED_MODE;
424 		hisi_i2c_set_scl(ctlr, 26, 76, HISI_I2C_FS_SCL_HCNT, HISI_I2C_FS_SCL_LCNT);
425 		break;
426 	case I2C_MAX_HIGH_SPEED_MODE_FREQ:
427 		speed_mode = HISI_I2C_HIGH_SPEED_MODE;
428 		hisi_i2c_set_scl(ctlr, 6, 22, HISI_I2C_HS_SCL_HCNT, HISI_I2C_HS_SCL_LCNT);
429 		break;
430 	case I2C_MAX_STANDARD_MODE_FREQ:
431 	default:
432 		speed_mode = HISI_I2C_STD_SPEED_MODE;
433 
434 		/* For default condition force the bus speed to standard mode. */
435 		ctlr->t.bus_freq_hz = I2C_MAX_STANDARD_MODE_FREQ;
436 		hisi_i2c_set_scl(ctlr, 40, 87, HISI_I2C_SS_SCL_HCNT, HISI_I2C_SS_SCL_LCNT);
437 		break;
438 	}
439 
440 	reg = readl(ctlr->iobase + HISI_I2C_FRAME_CTRL);
441 	reg &= ~HISI_I2C_FRAME_CTRL_SPEED_MODE;
442 	reg |= FIELD_PREP(HISI_I2C_FRAME_CTRL_SPEED_MODE, speed_mode);
443 	writel(reg, ctlr->iobase + HISI_I2C_FRAME_CTRL);
444 
445 	sda_hold_cnt = NSEC_TO_CYCLES(ctlr->t.sda_hold_ns, ctlr->clk_rate_khz);
446 
447 	reg = FIELD_PREP(HISI_I2C_SDA_HOLD_TX, sda_hold_cnt);
448 	writel(reg, ctlr->iobase + HISI_I2C_SDA_HOLD);
449 
450 	writel(ctlr->spk_len, ctlr->iobase + HISI_I2C_FS_SPK_LEN);
451 
452 	reg = FIELD_PREP(HISI_I2C_FIFO_RX_AF_THRESH, HISI_I2C_RX_F_AF_THRESH);
453 	reg |= FIELD_PREP(HISI_I2C_FIFO_TX_AE_THRESH, HISI_I2C_TX_F_AE_THRESH);
454 	writel(reg, ctlr->iobase + HISI_I2C_FIFO_CTRL);
455 }
456 
hisi_i2c_probe(struct platform_device * pdev)457 static int hisi_i2c_probe(struct platform_device *pdev)
458 {
459 	struct hisi_i2c_controller *ctlr;
460 	struct device *dev = &pdev->dev;
461 	struct i2c_adapter *adapter;
462 	u64 clk_rate_hz;
463 	u32 hw_version;
464 	int ret;
465 
466 	ctlr = devm_kzalloc(dev, sizeof(*ctlr), GFP_KERNEL);
467 	if (!ctlr)
468 		return -ENOMEM;
469 
470 	ctlr->iobase = devm_platform_ioremap_resource(pdev, 0);
471 	if (IS_ERR(ctlr->iobase))
472 		return PTR_ERR(ctlr->iobase);
473 
474 	ctlr->irq = platform_get_irq(pdev, 0);
475 	if (ctlr->irq < 0)
476 		return ctlr->irq;
477 
478 	ctlr->dev = dev;
479 
480 	hisi_i2c_disable_int(ctlr, HISI_I2C_INT_ALL);
481 
482 	ret = devm_request_irq(dev, ctlr->irq, hisi_i2c_irq, 0, "hisi-i2c", ctlr);
483 	if (ret)
484 		return ret;
485 
486 	ctlr->clk = devm_clk_get_optional_enabled(&pdev->dev, NULL);
487 	if (IS_ERR_OR_NULL(ctlr->clk)) {
488 		ret = device_property_read_u64(dev, "clk_rate", &clk_rate_hz);
489 		if (ret)
490 			return dev_err_probe(dev, ret, "failed to get clock frequency\n");
491 	} else {
492 		clk_rate_hz = clk_get_rate(ctlr->clk);
493 	}
494 
495 	ctlr->clk_rate_khz = DIV_ROUND_UP_ULL(clk_rate_hz, HZ_PER_KHZ);
496 
497 	hisi_i2c_configure_bus(ctlr);
498 
499 	adapter = &ctlr->adapter;
500 	snprintf(adapter->name, sizeof(adapter->name),
501 		 "HiSilicon I2C Controller %s", dev_name(dev));
502 	adapter->owner = THIS_MODULE;
503 	adapter->algo = &hisi_i2c_algo;
504 	adapter->dev.parent = dev;
505 	i2c_set_adapdata(adapter, ctlr);
506 
507 	ret = devm_i2c_add_adapter(dev, adapter);
508 	if (ret)
509 		return ret;
510 
511 	hw_version = readl(ctlr->iobase + HISI_I2C_VERSION);
512 	dev_info(ctlr->dev, "speed mode is %s. hw version 0x%x\n",
513 		 i2c_freq_mode_string(ctlr->t.bus_freq_hz), hw_version);
514 
515 	return 0;
516 }
517 
518 static const struct acpi_device_id hisi_i2c_acpi_ids[] = {
519 	{ "HISI03D1", 0 },
520 	{ }
521 };
522 MODULE_DEVICE_TABLE(acpi, hisi_i2c_acpi_ids);
523 
524 static const struct of_device_id hisi_i2c_dts_ids[] = {
525 	{ .compatible = "hisilicon,ascend910-i2c", },
526 	{ }
527 };
528 MODULE_DEVICE_TABLE(of, hisi_i2c_dts_ids);
529 
530 static struct platform_driver hisi_i2c_driver = {
531 	.probe		= hisi_i2c_probe,
532 	.driver		= {
533 		.name	= "hisi-i2c",
534 		.acpi_match_table = hisi_i2c_acpi_ids,
535 		.of_match_table = hisi_i2c_dts_ids,
536 	},
537 };
538 module_platform_driver(hisi_i2c_driver);
539 
540 MODULE_AUTHOR("Yicong Yang <yangyicong@hisilicon.com>");
541 MODULE_DESCRIPTION("HiSilicon I2C Controller Driver");
542 MODULE_LICENSE("GPL");
543