xref: /linux/drivers/i2c/busses/i2c-hisi.c (revision a9aaf1ff88a8cb99a1335c9eb76de637f0cf8c10)
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/mod_devicetable.h>
17 #include <linux/platform_device.h>
18 #include <linux/property.h>
19 #include <linux/units.h>
20 
21 #define HISI_I2C_FRAME_CTRL		0x0000
22 #define   HISI_I2C_FRAME_CTRL_SPEED_MODE	GENMASK(1, 0)
23 #define   HISI_I2C_FRAME_CTRL_ADDR_TEN	BIT(2)
24 #define HISI_I2C_SLV_ADDR		0x0004
25 #define   HISI_I2C_SLV_ADDR_VAL		GENMASK(9, 0)
26 #define   HISI_I2C_SLV_ADDR_GC_S_MODE	BIT(10)
27 #define   HISI_I2C_SLV_ADDR_GC_S_EN	BIT(11)
28 #define HISI_I2C_CMD_TXDATA		0x0008
29 #define   HISI_I2C_CMD_TXDATA_DATA	GENMASK(7, 0)
30 #define   HISI_I2C_CMD_TXDATA_RW	BIT(8)
31 #define   HISI_I2C_CMD_TXDATA_P_EN	BIT(9)
32 #define   HISI_I2C_CMD_TXDATA_SR_EN	BIT(10)
33 #define HISI_I2C_RXDATA			0x000c
34 #define   HISI_I2C_RXDATA_DATA		GENMASK(7, 0)
35 #define HISI_I2C_SS_SCL_HCNT		0x0010
36 #define HISI_I2C_SS_SCL_LCNT		0x0014
37 #define HISI_I2C_FS_SCL_HCNT		0x0018
38 #define HISI_I2C_FS_SCL_LCNT		0x001c
39 #define HISI_I2C_HS_SCL_HCNT		0x0020
40 #define HISI_I2C_HS_SCL_LCNT		0x0024
41 #define HISI_I2C_FIFO_CTRL		0x0028
42 #define   HISI_I2C_FIFO_RX_CLR		BIT(0)
43 #define   HISI_I2C_FIFO_TX_CLR		BIT(1)
44 #define   HISI_I2C_FIFO_RX_AF_THRESH	GENMASK(7, 2)
45 #define   HISI_I2C_FIFO_TX_AE_THRESH	GENMASK(13, 8)
46 #define HISI_I2C_FIFO_STATE		0x002c
47 #define   HISI_I2C_FIFO_STATE_RX_RERR	BIT(0)
48 #define   HISI_I2C_FIFO_STATE_RX_WERR	BIT(1)
49 #define   HISI_I2C_FIFO_STATE_RX_EMPTY	BIT(3)
50 #define   HISI_I2C_FIFO_STATE_TX_RERR	BIT(6)
51 #define   HISI_I2C_FIFO_STATE_TX_WERR	BIT(7)
52 #define   HISI_I2C_FIFO_STATE_TX_FULL	BIT(11)
53 #define HISI_I2C_SDA_HOLD		0x0030
54 #define   HISI_I2C_SDA_HOLD_TX		GENMASK(15, 0)
55 #define   HISI_I2C_SDA_HOLD_RX		GENMASK(23, 16)
56 #define HISI_I2C_FS_SPK_LEN		0x0038
57 #define   HISI_I2C_FS_SPK_LEN_CNT	GENMASK(7, 0)
58 #define HISI_I2C_HS_SPK_LEN		0x003c
59 #define   HISI_I2C_HS_SPK_LEN_CNT	GENMASK(7, 0)
60 #define HISI_I2C_TX_INT_CLR		0x0040
61 #define   HISI_I2C_TX_AEMPTY_INT		BIT(0)
62 #define HISI_I2C_INT_MSTAT		0x0044
63 #define HISI_I2C_INT_CLR		0x0048
64 #define HISI_I2C_INT_MASK		0x004C
65 #define HISI_I2C_TRANS_STATE		0x0050
66 #define HISI_I2C_TRANS_ERR		0x0054
67 #define HISI_I2C_VERSION		0x0058
68 
69 #define HISI_I2C_INT_ALL	GENMASK(4, 0)
70 #define HISI_I2C_INT_TRANS_CPLT	BIT(0)
71 #define HISI_I2C_INT_TRANS_ERR	BIT(1)
72 #define HISI_I2C_INT_FIFO_ERR	BIT(2)
73 #define HISI_I2C_INT_RX_FULL	BIT(3)
74 #define HISI_I2C_INT_TX_EMPTY	BIT(4)
75 #define HISI_I2C_INT_ERR \
76 	(HISI_I2C_INT_TRANS_ERR | HISI_I2C_INT_FIFO_ERR)
77 
78 #define HISI_I2C_STD_SPEED_MODE		0
79 #define HISI_I2C_FAST_SPEED_MODE	1
80 #define HISI_I2C_HIGH_SPEED_MODE	2
81 
82 #define HISI_I2C_TX_FIFO_DEPTH		64
83 #define HISI_I2C_RX_FIFO_DEPTH		64
84 #define HISI_I2C_TX_F_AE_THRESH		1
85 #define HISI_I2C_RX_F_AF_THRESH		60
86 
87 #define NSEC_TO_CYCLES(ns, clk_rate_khz) \
88 	DIV_ROUND_UP_ULL((clk_rate_khz) * (ns), NSEC_PER_MSEC)
89 
90 struct hisi_i2c_controller {
91 	struct i2c_adapter adapter;
92 	void __iomem *iobase;
93 	struct device *dev;
94 	struct clk *clk;
95 	int irq;
96 
97 	/* Intermediates for recording the transfer process */
98 	struct completion *completion;
99 	struct i2c_msg *msgs;
100 	int msg_num;
101 	int msg_tx_idx;
102 	int buf_tx_idx;
103 	int msg_rx_idx;
104 	int buf_rx_idx;
105 	u16 tar_addr;
106 	u32 xfer_err;
107 
108 	/* I2C bus configuration */
109 	struct i2c_timings t;
110 	u32 clk_rate_khz;
111 	u32 spk_len;
112 };
113 
114 static void hisi_i2c_enable_int(struct hisi_i2c_controller *ctlr, u32 mask)
115 {
116 	writel_relaxed(mask, ctlr->iobase + HISI_I2C_INT_MASK);
117 }
118 
119 static void hisi_i2c_disable_int(struct hisi_i2c_controller *ctlr, u32 mask)
120 {
121 	writel_relaxed((~mask) & HISI_I2C_INT_ALL, ctlr->iobase + HISI_I2C_INT_MASK);
122 }
123 
124 static void hisi_i2c_clear_int(struct hisi_i2c_controller *ctlr, u32 mask)
125 {
126 	writel_relaxed(mask, ctlr->iobase + HISI_I2C_INT_CLR);
127 }
128 
129 static void hisi_i2c_clear_tx_int(struct hisi_i2c_controller *ctlr, u32 mask)
130 {
131 	writel_relaxed(mask, ctlr->iobase + HISI_I2C_TX_INT_CLR);
132 }
133 
134 static void hisi_i2c_handle_errors(struct hisi_i2c_controller *ctlr)
135 {
136 	u32 int_err = ctlr->xfer_err, reg;
137 
138 	if (int_err & HISI_I2C_INT_FIFO_ERR) {
139 		reg = readl(ctlr->iobase + HISI_I2C_FIFO_STATE);
140 
141 		if (reg & HISI_I2C_FIFO_STATE_RX_RERR)
142 			dev_err(ctlr->dev, "rx fifo error read\n");
143 
144 		if (reg & HISI_I2C_FIFO_STATE_RX_WERR)
145 			dev_err(ctlr->dev, "rx fifo error write\n");
146 
147 		if (reg & HISI_I2C_FIFO_STATE_TX_RERR)
148 			dev_err(ctlr->dev, "tx fifo error read\n");
149 
150 		if (reg & HISI_I2C_FIFO_STATE_TX_WERR)
151 			dev_err(ctlr->dev, "tx fifo error write\n");
152 	}
153 }
154 
155 static int hisi_i2c_start_xfer(struct hisi_i2c_controller *ctlr)
156 {
157 	struct i2c_msg *msg = ctlr->msgs;
158 	u32 reg;
159 
160 	reg = readl(ctlr->iobase + HISI_I2C_FRAME_CTRL);
161 	reg &= ~HISI_I2C_FRAME_CTRL_ADDR_TEN;
162 	if (msg->flags & I2C_M_TEN)
163 		reg |= HISI_I2C_FRAME_CTRL_ADDR_TEN;
164 	writel(reg, ctlr->iobase + HISI_I2C_FRAME_CTRL);
165 
166 	reg = readl(ctlr->iobase + HISI_I2C_SLV_ADDR);
167 	reg &= ~HISI_I2C_SLV_ADDR_VAL;
168 	reg |= FIELD_PREP(HISI_I2C_SLV_ADDR_VAL, msg->addr);
169 	writel(reg, ctlr->iobase + HISI_I2C_SLV_ADDR);
170 
171 	reg = readl(ctlr->iobase + HISI_I2C_FIFO_CTRL);
172 	reg |= HISI_I2C_FIFO_RX_CLR | HISI_I2C_FIFO_TX_CLR;
173 	writel(reg, ctlr->iobase + HISI_I2C_FIFO_CTRL);
174 	reg &= ~(HISI_I2C_FIFO_RX_CLR | HISI_I2C_FIFO_TX_CLR);
175 	writel(reg, ctlr->iobase + HISI_I2C_FIFO_CTRL);
176 
177 	hisi_i2c_clear_int(ctlr, HISI_I2C_INT_ALL);
178 	hisi_i2c_clear_tx_int(ctlr, HISI_I2C_TX_AEMPTY_INT);
179 	hisi_i2c_enable_int(ctlr, HISI_I2C_INT_ALL);
180 
181 	return 0;
182 }
183 
184 static void hisi_i2c_reset_xfer(struct hisi_i2c_controller *ctlr)
185 {
186 	ctlr->msg_num = 0;
187 	ctlr->xfer_err = 0;
188 	ctlr->msg_tx_idx = 0;
189 	ctlr->msg_rx_idx = 0;
190 	ctlr->buf_tx_idx = 0;
191 	ctlr->buf_rx_idx = 0;
192 }
193 
194 /*
195  * Initialize the transfer information and start the I2C bus transfer.
196  * We only configure the transfer and do some pre/post works here, and
197  * wait for the transfer done. The major transfer process is performed
198  * in the IRQ handler.
199  */
200 static int hisi_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
201 			 int num)
202 {
203 	struct hisi_i2c_controller *ctlr = i2c_get_adapdata(adap);
204 	DECLARE_COMPLETION_ONSTACK(done);
205 	int ret = num;
206 
207 	hisi_i2c_reset_xfer(ctlr);
208 	ctlr->completion = &done;
209 	ctlr->msg_num = num;
210 	ctlr->msgs = msgs;
211 
212 	hisi_i2c_start_xfer(ctlr);
213 
214 	if (!wait_for_completion_timeout(ctlr->completion, adap->timeout)) {
215 		hisi_i2c_disable_int(ctlr, HISI_I2C_INT_ALL);
216 		synchronize_irq(ctlr->irq);
217 		i2c_recover_bus(&ctlr->adapter);
218 		dev_err(ctlr->dev, "bus transfer timeout\n");
219 		ret = -EIO;
220 	}
221 
222 	if (ctlr->xfer_err) {
223 		hisi_i2c_handle_errors(ctlr);
224 		ret = -EIO;
225 	}
226 
227 	hisi_i2c_reset_xfer(ctlr);
228 	ctlr->completion = NULL;
229 
230 	return ret;
231 }
232 
233 static u32 hisi_i2c_functionality(struct i2c_adapter *adap)
234 {
235 	return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL;
236 }
237 
238 static const struct i2c_algorithm hisi_i2c_algo = {
239 	.xfer = hisi_i2c_xfer,
240 	.functionality = hisi_i2c_functionality,
241 };
242 
243 static int hisi_i2c_read_rx_fifo(struct hisi_i2c_controller *ctlr)
244 {
245 	struct i2c_msg *cur_msg;
246 	u32 fifo_state;
247 
248 	while (ctlr->msg_rx_idx < ctlr->msg_num) {
249 		cur_msg = ctlr->msgs + ctlr->msg_rx_idx;
250 
251 		if (!(cur_msg->flags & I2C_M_RD)) {
252 			ctlr->msg_rx_idx++;
253 			continue;
254 		}
255 
256 		fifo_state = readl(ctlr->iobase + HISI_I2C_FIFO_STATE);
257 		while (!(fifo_state & HISI_I2C_FIFO_STATE_RX_EMPTY) &&
258 		       ctlr->buf_rx_idx < cur_msg->len) {
259 			cur_msg->buf[ctlr->buf_rx_idx++] = readl(ctlr->iobase + HISI_I2C_RXDATA);
260 			fifo_state = readl(ctlr->iobase + HISI_I2C_FIFO_STATE);
261 		}
262 
263 		if (ctlr->buf_rx_idx == cur_msg->len) {
264 			ctlr->buf_rx_idx = 0;
265 			ctlr->msg_rx_idx++;
266 		}
267 
268 		if (fifo_state & HISI_I2C_FIFO_STATE_RX_EMPTY)
269 			break;
270 	}
271 
272 	return 0;
273 }
274 
275 static void hisi_i2c_xfer_msg(struct hisi_i2c_controller *ctlr)
276 {
277 	int max_write = HISI_I2C_TX_FIFO_DEPTH - HISI_I2C_TX_F_AE_THRESH;
278 	bool need_restart = false, last_msg;
279 	struct i2c_msg *cur_msg;
280 	u32 cmd, fifo_state;
281 
282 	while (ctlr->msg_tx_idx < ctlr->msg_num) {
283 		cur_msg = ctlr->msgs + ctlr->msg_tx_idx;
284 		last_msg = (ctlr->msg_tx_idx == ctlr->msg_num - 1);
285 
286 		/* Signal the SR bit when we start transferring a new message */
287 		if (ctlr->msg_tx_idx && !ctlr->buf_tx_idx)
288 			need_restart = true;
289 
290 		fifo_state = readl(ctlr->iobase + HISI_I2C_FIFO_STATE);
291 		while (!(fifo_state & HISI_I2C_FIFO_STATE_TX_FULL) &&
292 		       ctlr->buf_tx_idx < cur_msg->len && max_write) {
293 			cmd = 0;
294 
295 			if (need_restart) {
296 				cmd |= HISI_I2C_CMD_TXDATA_SR_EN;
297 				need_restart = false;
298 			}
299 
300 			/* Signal the STOP bit at the last frame of the last message */
301 			if (ctlr->buf_tx_idx == cur_msg->len - 1 && last_msg)
302 				cmd |= HISI_I2C_CMD_TXDATA_P_EN;
303 
304 			if (cur_msg->flags & I2C_M_RD)
305 				cmd |= HISI_I2C_CMD_TXDATA_RW;
306 			else
307 				cmd |= FIELD_PREP(HISI_I2C_CMD_TXDATA_DATA,
308 						  cur_msg->buf[ctlr->buf_tx_idx]);
309 
310 			writel(cmd, ctlr->iobase + HISI_I2C_CMD_TXDATA);
311 			ctlr->buf_tx_idx++;
312 			max_write--;
313 
314 			fifo_state = readl(ctlr->iobase + HISI_I2C_FIFO_STATE);
315 		}
316 
317 		/* Update the transfer index after per message transfer is done. */
318 		if (ctlr->buf_tx_idx == cur_msg->len) {
319 			ctlr->buf_tx_idx = 0;
320 			ctlr->msg_tx_idx++;
321 		}
322 
323 		if ((fifo_state & HISI_I2C_FIFO_STATE_TX_FULL) ||
324 		    max_write == 0)
325 			break;
326 	}
327 
328 	/*
329 	 * Disable the TX_EMPTY interrupt after finishing all the messages to
330 	 * avoid overwhelming the CPU.
331 	 */
332 	if (ctlr->msg_tx_idx == ctlr->msg_num)
333 		hisi_i2c_disable_int(ctlr, HISI_I2C_INT_TX_EMPTY);
334 
335 	hisi_i2c_clear_tx_int(ctlr, HISI_I2C_TX_AEMPTY_INT);
336 }
337 
338 static irqreturn_t hisi_i2c_irq(int irq, void *context)
339 {
340 	struct hisi_i2c_controller *ctlr = context;
341 	u32 int_stat;
342 
343 	/*
344 	 * Don't handle the interrupt if cltr->completion is NULL. We may
345 	 * reach here because the interrupt is spurious or the transfer is
346 	 * started by another port (e.g. firmware) rather than us.
347 	 */
348 	if (!ctlr->completion)
349 		return IRQ_NONE;
350 
351 	int_stat = readl(ctlr->iobase + HISI_I2C_INT_MSTAT);
352 	hisi_i2c_clear_int(ctlr, int_stat);
353 	if (!(int_stat & HISI_I2C_INT_ALL))
354 		return IRQ_NONE;
355 
356 	if (int_stat & HISI_I2C_INT_TX_EMPTY)
357 		hisi_i2c_xfer_msg(ctlr);
358 
359 	if (int_stat & HISI_I2C_INT_ERR) {
360 		ctlr->xfer_err = int_stat;
361 		goto out;
362 	}
363 
364 	/* Drain the rx fifo before finish the transfer */
365 	if (int_stat & (HISI_I2C_INT_TRANS_CPLT | HISI_I2C_INT_RX_FULL))
366 		hisi_i2c_read_rx_fifo(ctlr);
367 
368 out:
369 	/*
370 	 * Only use TRANS_CPLT to indicate the completion. On error cases we'll
371 	 * get two interrupts, INT_ERR first then TRANS_CPLT.
372 	 */
373 	if (int_stat & HISI_I2C_INT_TRANS_CPLT) {
374 		hisi_i2c_disable_int(ctlr, HISI_I2C_INT_ALL);
375 		hisi_i2c_clear_int(ctlr, HISI_I2C_INT_ALL);
376 		hisi_i2c_clear_tx_int(ctlr, HISI_I2C_TX_AEMPTY_INT);
377 		complete(ctlr->completion);
378 	}
379 
380 	return IRQ_HANDLED;
381 }
382 
383 /*
384  * Helper function for calculating and configuring the HIGH and LOW
385  * periods of SCL clock. The caller will pass the ratio of the
386  * counts (divide / divisor) according to the target speed mode,
387  * and the target registers.
388  */
389 static void hisi_i2c_set_scl(struct hisi_i2c_controller *ctlr,
390 			     u32 divide, u32 divisor,
391 			     u32 reg_hcnt, u32 reg_lcnt)
392 {
393 	u32 total_cnt, t_scl_hcnt, t_scl_lcnt, scl_fall_cnt, scl_rise_cnt;
394 	u32 scl_hcnt, scl_lcnt;
395 
396 	/* Total SCL clock cycles per speed period */
397 	total_cnt = DIV_ROUND_UP_ULL(ctlr->clk_rate_khz * HZ_PER_KHZ, ctlr->t.bus_freq_hz);
398 	/* Total HIGH level SCL clock cycles including edges */
399 	t_scl_hcnt = DIV_ROUND_UP_ULL(total_cnt * divide, divisor);
400 	/* Total LOW level SCL clock cycles including edges */
401 	t_scl_lcnt = total_cnt - t_scl_hcnt;
402 	/* Fall edge SCL clock cycles */
403 	scl_fall_cnt = NSEC_TO_CYCLES(ctlr->t.scl_fall_ns, ctlr->clk_rate_khz);
404 	/* Rise edge SCL clock cycles */
405 	scl_rise_cnt = NSEC_TO_CYCLES(ctlr->t.scl_rise_ns, ctlr->clk_rate_khz);
406 
407 	/* Calculated HIGH and LOW periods of SCL clock */
408 	scl_hcnt = t_scl_hcnt - ctlr->spk_len - 7 - scl_fall_cnt;
409 	scl_lcnt = t_scl_lcnt - 1 - scl_rise_cnt;
410 
411 	writel(scl_hcnt, ctlr->iobase + reg_hcnt);
412 	writel(scl_lcnt, ctlr->iobase + reg_lcnt);
413 }
414 
415 static void hisi_i2c_configure_bus(struct hisi_i2c_controller *ctlr)
416 {
417 	u32 reg, sda_hold_cnt, speed_mode;
418 
419 	i2c_parse_fw_timings(ctlr->dev, &ctlr->t, true);
420 	ctlr->spk_len = NSEC_TO_CYCLES(ctlr->t.digital_filter_width_ns, ctlr->clk_rate_khz);
421 
422 	switch (ctlr->t.bus_freq_hz) {
423 	case I2C_MAX_FAST_MODE_FREQ:
424 		speed_mode = HISI_I2C_FAST_SPEED_MODE;
425 		hisi_i2c_set_scl(ctlr, 26, 76, HISI_I2C_FS_SCL_HCNT, HISI_I2C_FS_SCL_LCNT);
426 		break;
427 	case I2C_MAX_HIGH_SPEED_MODE_FREQ:
428 		speed_mode = HISI_I2C_HIGH_SPEED_MODE;
429 		hisi_i2c_set_scl(ctlr, 6, 22, HISI_I2C_HS_SCL_HCNT, HISI_I2C_HS_SCL_LCNT);
430 		break;
431 	case I2C_MAX_STANDARD_MODE_FREQ:
432 	default:
433 		speed_mode = HISI_I2C_STD_SPEED_MODE;
434 
435 		/* For default condition force the bus speed to standard mode. */
436 		ctlr->t.bus_freq_hz = I2C_MAX_STANDARD_MODE_FREQ;
437 		hisi_i2c_set_scl(ctlr, 40, 87, HISI_I2C_SS_SCL_HCNT, HISI_I2C_SS_SCL_LCNT);
438 		break;
439 	}
440 
441 	reg = readl(ctlr->iobase + HISI_I2C_FRAME_CTRL);
442 	reg &= ~HISI_I2C_FRAME_CTRL_SPEED_MODE;
443 	reg |= FIELD_PREP(HISI_I2C_FRAME_CTRL_SPEED_MODE, speed_mode);
444 	writel(reg, ctlr->iobase + HISI_I2C_FRAME_CTRL);
445 
446 	sda_hold_cnt = NSEC_TO_CYCLES(ctlr->t.sda_hold_ns, ctlr->clk_rate_khz);
447 
448 	reg = FIELD_PREP(HISI_I2C_SDA_HOLD_TX, sda_hold_cnt);
449 	writel(reg, ctlr->iobase + HISI_I2C_SDA_HOLD);
450 
451 	writel(ctlr->spk_len, ctlr->iobase + HISI_I2C_FS_SPK_LEN);
452 
453 	reg = FIELD_PREP(HISI_I2C_FIFO_RX_AF_THRESH, HISI_I2C_RX_F_AF_THRESH);
454 	reg |= FIELD_PREP(HISI_I2C_FIFO_TX_AE_THRESH, HISI_I2C_TX_F_AE_THRESH);
455 	writel(reg, ctlr->iobase + HISI_I2C_FIFO_CTRL);
456 }
457 
458 static int hisi_i2c_probe(struct platform_device *pdev)
459 {
460 	struct hisi_i2c_controller *ctlr;
461 	struct device *dev = &pdev->dev;
462 	struct i2c_adapter *adapter;
463 	u64 clk_rate_hz;
464 	u32 hw_version;
465 	int ret;
466 
467 	ctlr = devm_kzalloc(dev, sizeof(*ctlr), GFP_KERNEL);
468 	if (!ctlr)
469 		return -ENOMEM;
470 
471 	ctlr->iobase = devm_platform_ioremap_resource(pdev, 0);
472 	if (IS_ERR(ctlr->iobase))
473 		return PTR_ERR(ctlr->iobase);
474 
475 	ctlr->irq = platform_get_irq(pdev, 0);
476 	if (ctlr->irq < 0)
477 		return ctlr->irq;
478 
479 	ctlr->dev = dev;
480 
481 	hisi_i2c_disable_int(ctlr, HISI_I2C_INT_ALL);
482 
483 	ret = devm_request_irq(dev, ctlr->irq, hisi_i2c_irq, 0, "hisi-i2c", ctlr);
484 	if (ret)
485 		return dev_err_probe(dev, ret, "failed to request irq handler\n");
486 
487 	ctlr->clk = devm_clk_get_optional_enabled(&pdev->dev, NULL);
488 	if (IS_ERR_OR_NULL(ctlr->clk)) {
489 		ret = device_property_read_u64(dev, "clk_rate", &clk_rate_hz);
490 		if (ret)
491 			return dev_err_probe(dev, ret, "failed to get clock frequency\n");
492 	} else {
493 		clk_rate_hz = clk_get_rate(ctlr->clk);
494 	}
495 
496 	ctlr->clk_rate_khz = DIV_ROUND_UP_ULL(clk_rate_hz, HZ_PER_KHZ);
497 
498 	hisi_i2c_configure_bus(ctlr);
499 
500 	adapter = &ctlr->adapter;
501 	snprintf(adapter->name, sizeof(adapter->name),
502 		 "HiSilicon I2C Controller %s", dev_name(dev));
503 	adapter->owner = THIS_MODULE;
504 	adapter->algo = &hisi_i2c_algo;
505 	adapter->dev.parent = dev;
506 	i2c_set_adapdata(adapter, ctlr);
507 
508 	ret = devm_i2c_add_adapter(dev, adapter);
509 	if (ret)
510 		return ret;
511 
512 	hw_version = readl(ctlr->iobase + HISI_I2C_VERSION);
513 	dev_info(ctlr->dev, "speed mode is %s. hw version 0x%x\n",
514 		 i2c_freq_mode_string(ctlr->t.bus_freq_hz), hw_version);
515 
516 	return 0;
517 }
518 
519 static const struct acpi_device_id hisi_i2c_acpi_ids[] = {
520 	{ "HISI03D1", 0 },
521 	{ }
522 };
523 MODULE_DEVICE_TABLE(acpi, hisi_i2c_acpi_ids);
524 
525 static const struct of_device_id hisi_i2c_dts_ids[] = {
526 	{ .compatible = "hisilicon,ascend910-i2c", },
527 	{ }
528 };
529 MODULE_DEVICE_TABLE(of, hisi_i2c_dts_ids);
530 
531 static struct platform_driver hisi_i2c_driver = {
532 	.probe		= hisi_i2c_probe,
533 	.driver		= {
534 		.name	= "hisi-i2c",
535 		.acpi_match_table = hisi_i2c_acpi_ids,
536 		.of_match_table = hisi_i2c_dts_ids,
537 	},
538 };
539 module_platform_driver(hisi_i2c_driver);
540 
541 MODULE_AUTHOR("Yicong Yang <yangyicong@hisilicon.com>");
542 MODULE_DESCRIPTION("HiSilicon I2C Controller Driver");
543 MODULE_LICENSE("GPL");
544