1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@socionext.com>
4 */
5
6#include <linux/clk.h>
7#include <linux/i2c.h>
8#include <linux/iopoll.h>
9#include <linux/interrupt.h>
10#include <linux/io.h>
11#include <linux/module.h>
12#include <linux/platform_device.h>
13
14#define UNIPHIER_FI2C_CR	0x00	/* control register */
15#define     UNIPHIER_FI2C_CR_MST	BIT(3)	/* master mode */
16#define     UNIPHIER_FI2C_CR_STA	BIT(2)	/* start condition */
17#define     UNIPHIER_FI2C_CR_STO	BIT(1)	/* stop condition */
18#define     UNIPHIER_FI2C_CR_NACK	BIT(0)	/* do not return ACK */
19#define UNIPHIER_FI2C_DTTX	0x04	/* TX FIFO */
20#define     UNIPHIER_FI2C_DTTX_CMD	BIT(8)	/* send command (slave addr) */
21#define     UNIPHIER_FI2C_DTTX_RD	BIT(0)	/* read transaction */
22#define UNIPHIER_FI2C_DTRX	0x04	/* RX FIFO */
23#define UNIPHIER_FI2C_SLAD	0x0c	/* slave address */
24#define UNIPHIER_FI2C_CYC	0x10	/* clock cycle control */
25#define UNIPHIER_FI2C_LCTL	0x14	/* clock low period control */
26#define UNIPHIER_FI2C_SSUT	0x18	/* restart/stop setup time control */
27#define UNIPHIER_FI2C_DSUT	0x1c	/* data setup time control */
28#define UNIPHIER_FI2C_INT	0x20	/* interrupt status */
29#define UNIPHIER_FI2C_IE	0x24	/* interrupt enable */
30#define UNIPHIER_FI2C_IC	0x28	/* interrupt clear */
31#define     UNIPHIER_FI2C_INT_TE	BIT(9)	/* TX FIFO empty */
32#define     UNIPHIER_FI2C_INT_RF	BIT(8)	/* RX FIFO full */
33#define     UNIPHIER_FI2C_INT_TC	BIT(7)	/* send complete (STOP) */
34#define     UNIPHIER_FI2C_INT_RC	BIT(6)	/* receive complete (STOP) */
35#define     UNIPHIER_FI2C_INT_TB	BIT(5)	/* sent specified bytes */
36#define     UNIPHIER_FI2C_INT_RB	BIT(4)	/* received specified bytes */
37#define     UNIPHIER_FI2C_INT_NA	BIT(2)	/* no ACK */
38#define     UNIPHIER_FI2C_INT_AL	BIT(1)	/* arbitration lost */
39#define UNIPHIER_FI2C_SR	0x2c	/* status register */
40#define     UNIPHIER_FI2C_SR_DB		BIT(12)	/* device busy */
41#define     UNIPHIER_FI2C_SR_STS	BIT(11)	/* stop condition detected */
42#define     UNIPHIER_FI2C_SR_BB		BIT(8)	/* bus busy */
43#define     UNIPHIER_FI2C_SR_RFF	BIT(3)	/* RX FIFO full */
44#define     UNIPHIER_FI2C_SR_RNE	BIT(2)	/* RX FIFO not empty */
45#define     UNIPHIER_FI2C_SR_TNF	BIT(1)	/* TX FIFO not full */
46#define     UNIPHIER_FI2C_SR_TFE	BIT(0)	/* TX FIFO empty */
47#define UNIPHIER_FI2C_RST	0x34	/* reset control */
48#define     UNIPHIER_FI2C_RST_TBRST	BIT(2)	/* clear TX FIFO */
49#define     UNIPHIER_FI2C_RST_RBRST	BIT(1)	/* clear RX FIFO */
50#define     UNIPHIER_FI2C_RST_RST	BIT(0)	/* forcible bus reset */
51#define UNIPHIER_FI2C_BM	0x38	/* bus monitor */
52#define     UNIPHIER_FI2C_BM_SDAO	BIT(3)	/* output for SDA line */
53#define     UNIPHIER_FI2C_BM_SDAS	BIT(2)	/* readback of SDA line */
54#define     UNIPHIER_FI2C_BM_SCLO	BIT(1)	/* output for SCL line */
55#define     UNIPHIER_FI2C_BM_SCLS	BIT(0)	/* readback of SCL line */
56#define UNIPHIER_FI2C_NOISE	0x3c	/* noise filter control */
57#define UNIPHIER_FI2C_TBC	0x40	/* TX byte count setting */
58#define UNIPHIER_FI2C_RBC	0x44	/* RX byte count setting */
59#define UNIPHIER_FI2C_TBCM	0x48	/* TX byte count monitor */
60#define UNIPHIER_FI2C_RBCM	0x4c	/* RX byte count monitor */
61#define UNIPHIER_FI2C_BRST	0x50	/* bus reset */
62#define     UNIPHIER_FI2C_BRST_FOEN	BIT(1)	/* normal operation */
63#define     UNIPHIER_FI2C_BRST_RSCL	BIT(0)	/* release SCL */
64
65#define UNIPHIER_FI2C_INT_FAULTS	\
66				(UNIPHIER_FI2C_INT_NA | UNIPHIER_FI2C_INT_AL)
67#define UNIPHIER_FI2C_INT_STOP		\
68				(UNIPHIER_FI2C_INT_TC | UNIPHIER_FI2C_INT_RC)
69
70#define UNIPHIER_FI2C_RD		BIT(0)
71#define UNIPHIER_FI2C_STOP		BIT(1)
72#define UNIPHIER_FI2C_MANUAL_NACK	BIT(2)
73#define UNIPHIER_FI2C_BYTE_WISE		BIT(3)
74#define UNIPHIER_FI2C_DEFER_STOP_COMP	BIT(4)
75
76#define UNIPHIER_FI2C_FIFO_SIZE		8
77
78struct uniphier_fi2c_priv {
79	struct completion comp;
80	struct i2c_adapter adap;
81	void __iomem *membase;
82	struct clk *clk;
83	unsigned int len;
84	u8 *buf;
85	u32 enabled_irqs;
86	int error;
87	unsigned int flags;
88	unsigned int busy_cnt;
89	unsigned int clk_cycle;
90	spinlock_t lock;	/* IRQ synchronization */
91};
92
93static void uniphier_fi2c_fill_txfifo(struct uniphier_fi2c_priv *priv,
94				      bool first)
95{
96	int fifo_space = UNIPHIER_FI2C_FIFO_SIZE;
97
98	/*
99	 * TX-FIFO stores slave address in it for the first access.
100	 * Decrement the counter.
101	 */
102	if (first)
103		fifo_space--;
104
105	while (priv->len) {
106		if (fifo_space-- <= 0)
107			break;
108
109		writel(*priv->buf++, priv->membase + UNIPHIER_FI2C_DTTX);
110		priv->len--;
111	}
112}
113
114static void uniphier_fi2c_drain_rxfifo(struct uniphier_fi2c_priv *priv)
115{
116	int fifo_left = priv->flags & UNIPHIER_FI2C_BYTE_WISE ?
117						1 : UNIPHIER_FI2C_FIFO_SIZE;
118
119	while (priv->len) {
120		if (fifo_left-- <= 0)
121			break;
122
123		*priv->buf++ = readl(priv->membase + UNIPHIER_FI2C_DTRX);
124		priv->len--;
125	}
126}
127
128static void uniphier_fi2c_set_irqs(struct uniphier_fi2c_priv *priv)
129{
130	writel(priv->enabled_irqs, priv->membase + UNIPHIER_FI2C_IE);
131}
132
133static void uniphier_fi2c_clear_irqs(struct uniphier_fi2c_priv *priv,
134				     u32 mask)
135{
136	writel(mask, priv->membase + UNIPHIER_FI2C_IC);
137}
138
139static void uniphier_fi2c_stop(struct uniphier_fi2c_priv *priv)
140{
141	priv->enabled_irqs |= UNIPHIER_FI2C_INT_STOP;
142	uniphier_fi2c_set_irqs(priv);
143	writel(UNIPHIER_FI2C_CR_MST | UNIPHIER_FI2C_CR_STO,
144	       priv->membase + UNIPHIER_FI2C_CR);
145}
146
147static irqreturn_t uniphier_fi2c_interrupt(int irq, void *dev_id)
148{
149	struct uniphier_fi2c_priv *priv = dev_id;
150	u32 irq_status;
151
152	spin_lock(&priv->lock);
153
154	irq_status = readl(priv->membase + UNIPHIER_FI2C_INT);
155	irq_status &= priv->enabled_irqs;
156
157	if (irq_status & UNIPHIER_FI2C_INT_STOP)
158		goto complete;
159
160	if (unlikely(irq_status & UNIPHIER_FI2C_INT_AL)) {
161		priv->error = -EAGAIN;
162		goto complete;
163	}
164
165	if (unlikely(irq_status & UNIPHIER_FI2C_INT_NA)) {
166		priv->error = -ENXIO;
167		if (priv->flags & UNIPHIER_FI2C_RD) {
168			/*
169			 * work around a hardware bug:
170			 * The receive-completed interrupt is never set even if
171			 * STOP condition is detected after the address phase
172			 * of read transaction fails to get ACK.
173			 * To avoid time-out error, we issue STOP here,
174			 * but do not wait for its completion.
175			 * It should be checked after exiting this handler.
176			 */
177			uniphier_fi2c_stop(priv);
178			priv->flags |= UNIPHIER_FI2C_DEFER_STOP_COMP;
179			goto complete;
180		}
181		goto stop;
182	}
183
184	if (irq_status & UNIPHIER_FI2C_INT_TE) {
185		if (!priv->len)
186			goto data_done;
187
188		uniphier_fi2c_fill_txfifo(priv, false);
189		goto handled;
190	}
191
192	if (irq_status & (UNIPHIER_FI2C_INT_RF | UNIPHIER_FI2C_INT_RB)) {
193		uniphier_fi2c_drain_rxfifo(priv);
194		/*
195		 * If the number of bytes to read is multiple of the FIFO size
196		 * (msg->len == 8, 16, 24, ...), the INT_RF bit is set a little
197		 * earlier than INT_RB. We wait for INT_RB to confirm the
198		 * completion of the current message.
199		 */
200		if (!priv->len && (irq_status & UNIPHIER_FI2C_INT_RB))
201			goto data_done;
202
203		if (unlikely(priv->flags & UNIPHIER_FI2C_MANUAL_NACK)) {
204			if (priv->len <= UNIPHIER_FI2C_FIFO_SIZE &&
205			    !(priv->flags & UNIPHIER_FI2C_BYTE_WISE)) {
206				priv->enabled_irqs |= UNIPHIER_FI2C_INT_RB;
207				uniphier_fi2c_set_irqs(priv);
208				priv->flags |= UNIPHIER_FI2C_BYTE_WISE;
209			}
210			if (priv->len <= 1)
211				writel(UNIPHIER_FI2C_CR_MST |
212				       UNIPHIER_FI2C_CR_NACK,
213				       priv->membase + UNIPHIER_FI2C_CR);
214		}
215
216		goto handled;
217	}
218
219	spin_unlock(&priv->lock);
220
221	return IRQ_NONE;
222
223data_done:
224	if (priv->flags & UNIPHIER_FI2C_STOP) {
225stop:
226		uniphier_fi2c_stop(priv);
227	} else {
228complete:
229		priv->enabled_irqs = 0;
230		uniphier_fi2c_set_irqs(priv);
231		complete(&priv->comp);
232	}
233
234handled:
235	/*
236	 * This controller makes a pause while any bit of the IRQ status is
237	 * asserted. Clear the asserted bit to kick the controller just before
238	 * exiting the handler.
239	 */
240	uniphier_fi2c_clear_irqs(priv, irq_status);
241
242	spin_unlock(&priv->lock);
243
244	return IRQ_HANDLED;
245}
246
247static void uniphier_fi2c_tx_init(struct uniphier_fi2c_priv *priv, u16 addr,
248				  bool repeat)
249{
250	priv->enabled_irqs |= UNIPHIER_FI2C_INT_TE;
251	uniphier_fi2c_set_irqs(priv);
252
253	/* do not use TX byte counter */
254	writel(0, priv->membase + UNIPHIER_FI2C_TBC);
255	/* set slave address */
256	writel(UNIPHIER_FI2C_DTTX_CMD | addr << 1,
257	       priv->membase + UNIPHIER_FI2C_DTTX);
258	/*
259	 * First chunk of data. For a repeated START condition, do not write
260	 * data to the TX fifo here to avoid the timing issue.
261	 */
262	if (!repeat)
263		uniphier_fi2c_fill_txfifo(priv, true);
264}
265
266static void uniphier_fi2c_rx_init(struct uniphier_fi2c_priv *priv, u16 addr)
267{
268	priv->flags |= UNIPHIER_FI2C_RD;
269
270	if (likely(priv->len < 256)) {
271		/*
272		 * If possible, use RX byte counter.
273		 * It can automatically handle NACK for the last byte.
274		 */
275		writel(priv->len, priv->membase + UNIPHIER_FI2C_RBC);
276		priv->enabled_irqs |= UNIPHIER_FI2C_INT_RF |
277				      UNIPHIER_FI2C_INT_RB;
278	} else {
279		/*
280		 * The byte counter can not count over 256.  In this case,
281		 * do not use it at all.  Drain data when FIFO gets full,
282		 * but treat the last portion as a special case.
283		 */
284		writel(0, priv->membase + UNIPHIER_FI2C_RBC);
285		priv->flags |= UNIPHIER_FI2C_MANUAL_NACK;
286		priv->enabled_irqs |= UNIPHIER_FI2C_INT_RF;
287	}
288
289	uniphier_fi2c_set_irqs(priv);
290
291	/* set slave address with RD bit */
292	writel(UNIPHIER_FI2C_DTTX_CMD | UNIPHIER_FI2C_DTTX_RD | addr << 1,
293	       priv->membase + UNIPHIER_FI2C_DTTX);
294}
295
296static void uniphier_fi2c_reset(struct uniphier_fi2c_priv *priv)
297{
298	writel(UNIPHIER_FI2C_RST_RST, priv->membase + UNIPHIER_FI2C_RST);
299}
300
301static void uniphier_fi2c_prepare_operation(struct uniphier_fi2c_priv *priv)
302{
303	writel(UNIPHIER_FI2C_BRST_FOEN | UNIPHIER_FI2C_BRST_RSCL,
304	       priv->membase + UNIPHIER_FI2C_BRST);
305}
306
307static void uniphier_fi2c_recover(struct uniphier_fi2c_priv *priv)
308{
309	uniphier_fi2c_reset(priv);
310	i2c_recover_bus(&priv->adap);
311}
312
313static int uniphier_fi2c_master_xfer_one(struct i2c_adapter *adap,
314					 struct i2c_msg *msg, bool repeat,
315					 bool stop)
316{
317	struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);
318	bool is_read = msg->flags & I2C_M_RD;
319	unsigned long time_left, flags;
320
321	priv->len = msg->len;
322	priv->buf = msg->buf;
323	priv->enabled_irqs = UNIPHIER_FI2C_INT_FAULTS;
324	priv->error = 0;
325	priv->flags = 0;
326
327	if (stop)
328		priv->flags |= UNIPHIER_FI2C_STOP;
329
330	reinit_completion(&priv->comp);
331	uniphier_fi2c_clear_irqs(priv, U32_MAX);
332	writel(UNIPHIER_FI2C_RST_TBRST | UNIPHIER_FI2C_RST_RBRST,
333	       priv->membase + UNIPHIER_FI2C_RST);	/* reset TX/RX FIFO */
334
335	spin_lock_irqsave(&priv->lock, flags);
336
337	if (is_read)
338		uniphier_fi2c_rx_init(priv, msg->addr);
339	else
340		uniphier_fi2c_tx_init(priv, msg->addr, repeat);
341
342	/*
343	 * For a repeated START condition, writing a slave address to the FIFO
344	 * kicks the controller. So, the UNIPHIER_FI2C_CR register should be
345	 * written only for a non-repeated START condition.
346	 */
347	if (!repeat)
348		writel(UNIPHIER_FI2C_CR_MST | UNIPHIER_FI2C_CR_STA,
349		       priv->membase + UNIPHIER_FI2C_CR);
350
351	spin_unlock_irqrestore(&priv->lock, flags);
352
353	time_left = wait_for_completion_timeout(&priv->comp, adap->timeout);
354
355	spin_lock_irqsave(&priv->lock, flags);
356	priv->enabled_irqs = 0;
357	uniphier_fi2c_set_irqs(priv);
358	spin_unlock_irqrestore(&priv->lock, flags);
359
360	if (!time_left) {
361		dev_err(&adap->dev, "transaction timeout.\n");
362		uniphier_fi2c_recover(priv);
363		return -ETIMEDOUT;
364	}
365
366	if (unlikely(priv->flags & UNIPHIER_FI2C_DEFER_STOP_COMP)) {
367		u32 status;
368		int ret;
369
370		ret = readl_poll_timeout(priv->membase + UNIPHIER_FI2C_SR,
371					 status,
372					 (status & UNIPHIER_FI2C_SR_STS) &&
373					 !(status & UNIPHIER_FI2C_SR_BB),
374					 1, 20);
375		if (ret) {
376			dev_err(&adap->dev,
377				"stop condition was not completed.\n");
378			uniphier_fi2c_recover(priv);
379			return ret;
380		}
381	}
382
383	return priv->error;
384}
385
386static int uniphier_fi2c_check_bus_busy(struct i2c_adapter *adap)
387{
388	struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);
389
390	if (readl(priv->membase + UNIPHIER_FI2C_SR) & UNIPHIER_FI2C_SR_DB) {
391		if (priv->busy_cnt++ > 3) {
392			/*
393			 * If bus busy continues too long, it is probably
394			 * in a wrong state.  Try bus recovery.
395			 */
396			uniphier_fi2c_recover(priv);
397			priv->busy_cnt = 0;
398		}
399
400		return -EAGAIN;
401	}
402
403	priv->busy_cnt = 0;
404	return 0;
405}
406
407static int uniphier_fi2c_master_xfer(struct i2c_adapter *adap,
408				     struct i2c_msg *msgs, int num)
409{
410	struct i2c_msg *msg, *emsg = msgs + num;
411	bool repeat = false;
412	int ret;
413
414	ret = uniphier_fi2c_check_bus_busy(adap);
415	if (ret)
416		return ret;
417
418	for (msg = msgs; msg < emsg; msg++) {
419		/* Emit STOP if it is the last message or I2C_M_STOP is set. */
420		bool stop = (msg + 1 == emsg) || (msg->flags & I2C_M_STOP);
421
422		ret = uniphier_fi2c_master_xfer_one(adap, msg, repeat, stop);
423		if (ret)
424			return ret;
425
426		repeat = !stop;
427	}
428
429	return num;
430}
431
432static u32 uniphier_fi2c_functionality(struct i2c_adapter *adap)
433{
434	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
435}
436
437static const struct i2c_algorithm uniphier_fi2c_algo = {
438	.master_xfer = uniphier_fi2c_master_xfer,
439	.functionality = uniphier_fi2c_functionality,
440};
441
442static int uniphier_fi2c_get_scl(struct i2c_adapter *adap)
443{
444	struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);
445
446	return !!(readl(priv->membase + UNIPHIER_FI2C_BM) &
447							UNIPHIER_FI2C_BM_SCLS);
448}
449
450static void uniphier_fi2c_set_scl(struct i2c_adapter *adap, int val)
451{
452	struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);
453
454	writel(val ? UNIPHIER_FI2C_BRST_RSCL : 0,
455	       priv->membase + UNIPHIER_FI2C_BRST);
456}
457
458static int uniphier_fi2c_get_sda(struct i2c_adapter *adap)
459{
460	struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);
461
462	return !!(readl(priv->membase + UNIPHIER_FI2C_BM) &
463							UNIPHIER_FI2C_BM_SDAS);
464}
465
466static void uniphier_fi2c_unprepare_recovery(struct i2c_adapter *adap)
467{
468	uniphier_fi2c_prepare_operation(i2c_get_adapdata(adap));
469}
470
471static struct i2c_bus_recovery_info uniphier_fi2c_bus_recovery_info = {
472	.recover_bus = i2c_generic_scl_recovery,
473	.get_scl = uniphier_fi2c_get_scl,
474	.set_scl = uniphier_fi2c_set_scl,
475	.get_sda = uniphier_fi2c_get_sda,
476	.unprepare_recovery = uniphier_fi2c_unprepare_recovery,
477};
478
479static void uniphier_fi2c_hw_init(struct uniphier_fi2c_priv *priv)
480{
481	unsigned int cyc = priv->clk_cycle;
482	u32 tmp;
483
484	tmp = readl(priv->membase + UNIPHIER_FI2C_CR);
485	tmp |= UNIPHIER_FI2C_CR_MST;
486	writel(tmp, priv->membase + UNIPHIER_FI2C_CR);
487
488	uniphier_fi2c_reset(priv);
489
490	/*
491	 *  Standard-mode: tLOW + tHIGH = 10 us
492	 *  Fast-mode:     tLOW + tHIGH = 2.5 us
493	 */
494	writel(cyc, priv->membase + UNIPHIER_FI2C_CYC);
495	/*
496	 *  Standard-mode: tLOW = 4.7 us, tHIGH = 4.0 us, tBUF = 4.7 us
497	 *  Fast-mode:     tLOW = 1.3 us, tHIGH = 0.6 us, tBUF = 1.3 us
498	 * "tLow/tHIGH = 5/4" meets both.
499	 */
500	writel(cyc * 5 / 9, priv->membase + UNIPHIER_FI2C_LCTL);
501	/*
502	 *  Standard-mode: tHD;STA = 4.0 us, tSU;STA = 4.7 us, tSU;STO = 4.0 us
503	 *  Fast-mode:     tHD;STA = 0.6 us, tSU;STA = 0.6 us, tSU;STO = 0.6 us
504	 */
505	writel(cyc / 2, priv->membase + UNIPHIER_FI2C_SSUT);
506	/*
507	 *  Standard-mode: tSU;DAT = 250 ns
508	 *  Fast-mode:     tSU;DAT = 100 ns
509	 */
510	writel(cyc / 16, priv->membase + UNIPHIER_FI2C_DSUT);
511
512	uniphier_fi2c_prepare_operation(priv);
513}
514
515static int uniphier_fi2c_probe(struct platform_device *pdev)
516{
517	struct device *dev = &pdev->dev;
518	struct uniphier_fi2c_priv *priv;
519	u32 bus_speed;
520	unsigned long clk_rate;
521	int irq, ret;
522
523	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
524	if (!priv)
525		return -ENOMEM;
526
527	priv->membase = devm_platform_ioremap_resource(pdev, 0);
528	if (IS_ERR(priv->membase))
529		return PTR_ERR(priv->membase);
530
531	irq = platform_get_irq(pdev, 0);
532	if (irq < 0)
533		return irq;
534
535	if (of_property_read_u32(dev->of_node, "clock-frequency", &bus_speed))
536		bus_speed = I2C_MAX_STANDARD_MODE_FREQ;
537
538	if (!bus_speed || bus_speed > I2C_MAX_FAST_MODE_FREQ) {
539		dev_err(dev, "invalid clock-frequency %d\n", bus_speed);
540		return -EINVAL;
541	}
542
543	priv->clk = devm_clk_get_enabled(dev, NULL);
544	if (IS_ERR(priv->clk)) {
545		dev_err(dev, "failed to enable clock\n");
546		return PTR_ERR(priv->clk);
547	}
548
549	clk_rate = clk_get_rate(priv->clk);
550	if (!clk_rate) {
551		dev_err(dev, "input clock rate should not be zero\n");
552		return -EINVAL;
553	}
554
555	priv->clk_cycle = clk_rate / bus_speed;
556	init_completion(&priv->comp);
557	spin_lock_init(&priv->lock);
558	priv->adap.owner = THIS_MODULE;
559	priv->adap.algo = &uniphier_fi2c_algo;
560	priv->adap.dev.parent = dev;
561	priv->adap.dev.of_node = dev->of_node;
562	strscpy(priv->adap.name, "UniPhier FI2C", sizeof(priv->adap.name));
563	priv->adap.bus_recovery_info = &uniphier_fi2c_bus_recovery_info;
564	i2c_set_adapdata(&priv->adap, priv);
565	platform_set_drvdata(pdev, priv);
566
567	uniphier_fi2c_hw_init(priv);
568
569	ret = devm_request_irq(dev, irq, uniphier_fi2c_interrupt, 0,
570			       pdev->name, priv);
571	if (ret) {
572		dev_err(dev, "failed to request irq %d\n", irq);
573		return ret;
574	}
575
576	return i2c_add_adapter(&priv->adap);
577}
578
579static void uniphier_fi2c_remove(struct platform_device *pdev)
580{
581	struct uniphier_fi2c_priv *priv = platform_get_drvdata(pdev);
582
583	i2c_del_adapter(&priv->adap);
584}
585
586static int __maybe_unused uniphier_fi2c_suspend(struct device *dev)
587{
588	struct uniphier_fi2c_priv *priv = dev_get_drvdata(dev);
589
590	clk_disable_unprepare(priv->clk);
591
592	return 0;
593}
594
595static int __maybe_unused uniphier_fi2c_resume(struct device *dev)
596{
597	struct uniphier_fi2c_priv *priv = dev_get_drvdata(dev);
598	int ret;
599
600	ret = clk_prepare_enable(priv->clk);
601	if (ret)
602		return ret;
603
604	uniphier_fi2c_hw_init(priv);
605
606	return 0;
607}
608
609static const struct dev_pm_ops uniphier_fi2c_pm_ops = {
610	SET_SYSTEM_SLEEP_PM_OPS(uniphier_fi2c_suspend, uniphier_fi2c_resume)
611};
612
613static const struct of_device_id uniphier_fi2c_match[] = {
614	{ .compatible = "socionext,uniphier-fi2c" },
615	{ /* sentinel */ }
616};
617MODULE_DEVICE_TABLE(of, uniphier_fi2c_match);
618
619static struct platform_driver uniphier_fi2c_drv = {
620	.probe  = uniphier_fi2c_probe,
621	.remove_new = uniphier_fi2c_remove,
622	.driver = {
623		.name  = "uniphier-fi2c",
624		.of_match_table = uniphier_fi2c_match,
625		.pm = &uniphier_fi2c_pm_ops,
626	},
627};
628module_platform_driver(uniphier_fi2c_drv);
629
630MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
631MODULE_DESCRIPTION("UniPhier FIFO-builtin I2C bus driver");
632MODULE_LICENSE("GPL");
633