1 /*
2  * Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@socionext.com>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  */
14 
15 #include <linux/clk.h>
16 #include <linux/i2c.h>
17 #include <linux/iopoll.h>
18 #include <linux/interrupt.h>
19 #include <linux/io.h>
20 #include <linux/module.h>
21 #include <linux/platform_device.h>
22 
23 #define UNIPHIER_FI2C_CR	0x00	/* control register */
24 #define     UNIPHIER_FI2C_CR_MST	BIT(3)	/* master mode */
25 #define     UNIPHIER_FI2C_CR_STA	BIT(2)	/* start condition */
26 #define     UNIPHIER_FI2C_CR_STO	BIT(1)	/* stop condition */
27 #define     UNIPHIER_FI2C_CR_NACK	BIT(0)	/* do not return ACK */
28 #define UNIPHIER_FI2C_DTTX	0x04	/* TX FIFO */
29 #define     UNIPHIER_FI2C_DTTX_CMD	BIT(8)	/* send command (slave addr) */
30 #define     UNIPHIER_FI2C_DTTX_RD	BIT(0)	/* read transaction */
31 #define UNIPHIER_FI2C_DTRX	0x04	/* RX FIFO */
32 #define UNIPHIER_FI2C_SLAD	0x0c	/* slave address */
33 #define UNIPHIER_FI2C_CYC	0x10	/* clock cycle control */
34 #define UNIPHIER_FI2C_LCTL	0x14	/* clock low period control */
35 #define UNIPHIER_FI2C_SSUT	0x18	/* restart/stop setup time control */
36 #define UNIPHIER_FI2C_DSUT	0x1c	/* data setup time control */
37 #define UNIPHIER_FI2C_INT	0x20	/* interrupt status */
38 #define UNIPHIER_FI2C_IE	0x24	/* interrupt enable */
39 #define UNIPHIER_FI2C_IC	0x28	/* interrupt clear */
40 #define     UNIPHIER_FI2C_INT_TE	BIT(9)	/* TX FIFO empty */
41 #define     UNIPHIER_FI2C_INT_RF	BIT(8)	/* RX FIFO full */
42 #define     UNIPHIER_FI2C_INT_TC	BIT(7)	/* send complete (STOP) */
43 #define     UNIPHIER_FI2C_INT_RC	BIT(6)	/* receive complete (STOP) */
44 #define     UNIPHIER_FI2C_INT_TB	BIT(5)	/* sent specified bytes */
45 #define     UNIPHIER_FI2C_INT_RB	BIT(4)	/* received specified bytes */
46 #define     UNIPHIER_FI2C_INT_NA	BIT(2)	/* no ACK */
47 #define     UNIPHIER_FI2C_INT_AL	BIT(1)	/* arbitration lost */
48 #define UNIPHIER_FI2C_SR	0x2c	/* status register */
49 #define     UNIPHIER_FI2C_SR_DB		BIT(12)	/* device busy */
50 #define     UNIPHIER_FI2C_SR_STS	BIT(11)	/* stop condition detected */
51 #define     UNIPHIER_FI2C_SR_BB		BIT(8)	/* bus busy */
52 #define     UNIPHIER_FI2C_SR_RFF	BIT(3)	/* RX FIFO full */
53 #define     UNIPHIER_FI2C_SR_RNE	BIT(2)	/* RX FIFO not empty */
54 #define     UNIPHIER_FI2C_SR_TNF	BIT(1)	/* TX FIFO not full */
55 #define     UNIPHIER_FI2C_SR_TFE	BIT(0)	/* TX FIFO empty */
56 #define UNIPHIER_FI2C_RST	0x34	/* reset control */
57 #define     UNIPHIER_FI2C_RST_TBRST	BIT(2)	/* clear TX FIFO */
58 #define     UNIPHIER_FI2C_RST_RBRST	BIT(1)	/* clear RX FIFO */
59 #define     UNIPHIER_FI2C_RST_RST	BIT(0)	/* forcible bus reset */
60 #define UNIPHIER_FI2C_BM	0x38	/* bus monitor */
61 #define     UNIPHIER_FI2C_BM_SDAO	BIT(3)	/* output for SDA line */
62 #define     UNIPHIER_FI2C_BM_SDAS	BIT(2)	/* readback of SDA line */
63 #define     UNIPHIER_FI2C_BM_SCLO	BIT(1)	/* output for SCL line */
64 #define     UNIPHIER_FI2C_BM_SCLS	BIT(0)	/* readback of SCL line */
65 #define UNIPHIER_FI2C_NOISE	0x3c	/* noise filter control */
66 #define UNIPHIER_FI2C_TBC	0x40	/* TX byte count setting */
67 #define UNIPHIER_FI2C_RBC	0x44	/* RX byte count setting */
68 #define UNIPHIER_FI2C_TBCM	0x48	/* TX byte count monitor */
69 #define UNIPHIER_FI2C_RBCM	0x4c	/* RX byte count monitor */
70 #define UNIPHIER_FI2C_BRST	0x50	/* bus reset */
71 #define     UNIPHIER_FI2C_BRST_FOEN	BIT(1)	/* normal operation */
72 #define     UNIPHIER_FI2C_BRST_RSCL	BIT(0)	/* release SCL */
73 
74 #define UNIPHIER_FI2C_INT_FAULTS	\
75 				(UNIPHIER_FI2C_INT_NA | UNIPHIER_FI2C_INT_AL)
76 #define UNIPHIER_FI2C_INT_STOP		\
77 				(UNIPHIER_FI2C_INT_TC | UNIPHIER_FI2C_INT_RC)
78 
79 #define UNIPHIER_FI2C_RD		BIT(0)
80 #define UNIPHIER_FI2C_STOP		BIT(1)
81 #define UNIPHIER_FI2C_MANUAL_NACK	BIT(2)
82 #define UNIPHIER_FI2C_BYTE_WISE		BIT(3)
83 #define UNIPHIER_FI2C_DEFER_STOP_COMP	BIT(4)
84 
85 #define UNIPHIER_FI2C_DEFAULT_SPEED	100000
86 #define UNIPHIER_FI2C_MAX_SPEED		400000
87 #define UNIPHIER_FI2C_FIFO_SIZE		8
88 
89 struct uniphier_fi2c_priv {
90 	struct completion comp;
91 	struct i2c_adapter adap;
92 	void __iomem *membase;
93 	struct clk *clk;
94 	unsigned int len;
95 	u8 *buf;
96 	u32 enabled_irqs;
97 	int error;
98 	unsigned int flags;
99 	unsigned int busy_cnt;
100 };
101 
102 static void uniphier_fi2c_fill_txfifo(struct uniphier_fi2c_priv *priv,
103 				      bool first)
104 {
105 	int fifo_space = UNIPHIER_FI2C_FIFO_SIZE;
106 
107 	/*
108 	 * TX-FIFO stores slave address in it for the first access.
109 	 * Decrement the counter.
110 	 */
111 	if (first)
112 		fifo_space--;
113 
114 	while (priv->len) {
115 		if (fifo_space-- <= 0)
116 			break;
117 
118 		dev_dbg(&priv->adap.dev, "write data: %02x\n", *priv->buf);
119 		writel(*priv->buf++, priv->membase + UNIPHIER_FI2C_DTTX);
120 		priv->len--;
121 	}
122 }
123 
124 static void uniphier_fi2c_drain_rxfifo(struct uniphier_fi2c_priv *priv)
125 {
126 	int fifo_left = priv->flags & UNIPHIER_FI2C_BYTE_WISE ?
127 						1 : UNIPHIER_FI2C_FIFO_SIZE;
128 
129 	while (priv->len) {
130 		if (fifo_left-- <= 0)
131 			break;
132 
133 		*priv->buf++ = readl(priv->membase + UNIPHIER_FI2C_DTRX);
134 		dev_dbg(&priv->adap.dev, "read data: %02x\n", priv->buf[-1]);
135 		priv->len--;
136 	}
137 }
138 
139 static void uniphier_fi2c_set_irqs(struct uniphier_fi2c_priv *priv)
140 {
141 	writel(priv->enabled_irqs, priv->membase + UNIPHIER_FI2C_IE);
142 }
143 
144 static void uniphier_fi2c_clear_irqs(struct uniphier_fi2c_priv *priv)
145 {
146 	writel(-1, priv->membase + UNIPHIER_FI2C_IC);
147 }
148 
149 static void uniphier_fi2c_stop(struct uniphier_fi2c_priv *priv)
150 {
151 	dev_dbg(&priv->adap.dev, "stop condition\n");
152 
153 	priv->enabled_irqs |= UNIPHIER_FI2C_INT_STOP;
154 	uniphier_fi2c_set_irqs(priv);
155 	writel(UNIPHIER_FI2C_CR_MST | UNIPHIER_FI2C_CR_STO,
156 	       priv->membase + UNIPHIER_FI2C_CR);
157 }
158 
159 static irqreturn_t uniphier_fi2c_interrupt(int irq, void *dev_id)
160 {
161 	struct uniphier_fi2c_priv *priv = dev_id;
162 	u32 irq_status;
163 
164 	irq_status = readl(priv->membase + UNIPHIER_FI2C_INT);
165 
166 	dev_dbg(&priv->adap.dev,
167 		"interrupt: enabled_irqs=%04x, irq_status=%04x\n",
168 		priv->enabled_irqs, irq_status);
169 
170 	if (irq_status & UNIPHIER_FI2C_INT_STOP)
171 		goto complete;
172 
173 	if (unlikely(irq_status & UNIPHIER_FI2C_INT_AL)) {
174 		dev_dbg(&priv->adap.dev, "arbitration lost\n");
175 		priv->error = -EAGAIN;
176 		goto complete;
177 	}
178 
179 	if (unlikely(irq_status & UNIPHIER_FI2C_INT_NA)) {
180 		dev_dbg(&priv->adap.dev, "could not get ACK\n");
181 		priv->error = -ENXIO;
182 		if (priv->flags & UNIPHIER_FI2C_RD) {
183 			/*
184 			 * work around a hardware bug:
185 			 * The receive-completed interrupt is never set even if
186 			 * STOP condition is detected after the address phase
187 			 * of read transaction fails to get ACK.
188 			 * To avoid time-out error, we issue STOP here,
189 			 * but do not wait for its completion.
190 			 * It should be checked after exiting this handler.
191 			 */
192 			uniphier_fi2c_stop(priv);
193 			priv->flags |= UNIPHIER_FI2C_DEFER_STOP_COMP;
194 			goto complete;
195 		}
196 		goto stop;
197 	}
198 
199 	if (irq_status & UNIPHIER_FI2C_INT_TE) {
200 		if (!priv->len)
201 			goto data_done;
202 
203 		uniphier_fi2c_fill_txfifo(priv, false);
204 		goto handled;
205 	}
206 
207 	if (irq_status & (UNIPHIER_FI2C_INT_RF | UNIPHIER_FI2C_INT_RB)) {
208 		uniphier_fi2c_drain_rxfifo(priv);
209 		if (!priv->len)
210 			goto data_done;
211 
212 		if (unlikely(priv->flags & UNIPHIER_FI2C_MANUAL_NACK)) {
213 			if (priv->len <= UNIPHIER_FI2C_FIFO_SIZE &&
214 			    !(priv->flags & UNIPHIER_FI2C_BYTE_WISE)) {
215 				dev_dbg(&priv->adap.dev,
216 					"enable read byte count IRQ\n");
217 				priv->enabled_irqs |= UNIPHIER_FI2C_INT_RB;
218 				uniphier_fi2c_set_irqs(priv);
219 				priv->flags |= UNIPHIER_FI2C_BYTE_WISE;
220 			}
221 			if (priv->len <= 1) {
222 				dev_dbg(&priv->adap.dev, "set NACK\n");
223 				writel(UNIPHIER_FI2C_CR_MST |
224 				       UNIPHIER_FI2C_CR_NACK,
225 				       priv->membase + UNIPHIER_FI2C_CR);
226 			}
227 		}
228 
229 		goto handled;
230 	}
231 
232 	return IRQ_NONE;
233 
234 data_done:
235 	if (priv->flags & UNIPHIER_FI2C_STOP) {
236 stop:
237 		uniphier_fi2c_stop(priv);
238 	} else {
239 complete:
240 		priv->enabled_irqs = 0;
241 		uniphier_fi2c_set_irqs(priv);
242 		complete(&priv->comp);
243 	}
244 
245 handled:
246 	uniphier_fi2c_clear_irqs(priv);
247 
248 	return IRQ_HANDLED;
249 }
250 
251 static void uniphier_fi2c_tx_init(struct uniphier_fi2c_priv *priv, u16 addr)
252 {
253 	priv->enabled_irqs |= UNIPHIER_FI2C_INT_TE;
254 	/* do not use TX byte counter */
255 	writel(0, priv->membase + UNIPHIER_FI2C_TBC);
256 	/* set slave address */
257 	writel(UNIPHIER_FI2C_DTTX_CMD | addr << 1,
258 	       priv->membase + UNIPHIER_FI2C_DTTX);
259 	/* first chunk of data */
260 	uniphier_fi2c_fill_txfifo(priv, true);
261 }
262 
263 static void uniphier_fi2c_rx_init(struct uniphier_fi2c_priv *priv, u16 addr)
264 {
265 	priv->flags |= UNIPHIER_FI2C_RD;
266 
267 	if (likely(priv->len < 256)) {
268 		/*
269 		 * If possible, use RX byte counter.
270 		 * It can automatically handle NACK for the last byte.
271 		 */
272 		writel(priv->len, priv->membase + UNIPHIER_FI2C_RBC);
273 		priv->enabled_irqs |= UNIPHIER_FI2C_INT_RF |
274 				      UNIPHIER_FI2C_INT_RB;
275 	} else {
276 		/*
277 		 * The byte counter can not count over 256.  In this case,
278 		 * do not use it at all.  Drain data when FIFO gets full,
279 		 * but treat the last portion as a special case.
280 		 */
281 		writel(0, priv->membase + UNIPHIER_FI2C_RBC);
282 		priv->flags |= UNIPHIER_FI2C_MANUAL_NACK;
283 		priv->enabled_irqs |= UNIPHIER_FI2C_INT_RF;
284 	}
285 
286 	/* set slave address with RD bit */
287 	writel(UNIPHIER_FI2C_DTTX_CMD | UNIPHIER_FI2C_DTTX_RD | addr << 1,
288 	       priv->membase + UNIPHIER_FI2C_DTTX);
289 }
290 
291 static void uniphier_fi2c_reset(struct uniphier_fi2c_priv *priv)
292 {
293 	writel(UNIPHIER_FI2C_RST_RST, priv->membase + UNIPHIER_FI2C_RST);
294 }
295 
296 static void uniphier_fi2c_prepare_operation(struct uniphier_fi2c_priv *priv)
297 {
298 	writel(UNIPHIER_FI2C_BRST_FOEN | UNIPHIER_FI2C_BRST_RSCL,
299 	       priv->membase + UNIPHIER_FI2C_BRST);
300 }
301 
302 static void uniphier_fi2c_recover(struct uniphier_fi2c_priv *priv)
303 {
304 	uniphier_fi2c_reset(priv);
305 	i2c_recover_bus(&priv->adap);
306 }
307 
308 static int uniphier_fi2c_master_xfer_one(struct i2c_adapter *adap,
309 					 struct i2c_msg *msg, bool stop)
310 {
311 	struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);
312 	bool is_read = msg->flags & I2C_M_RD;
313 	unsigned long time_left;
314 
315 	dev_dbg(&adap->dev, "%s: addr=0x%02x, len=%d, stop=%d\n",
316 		is_read ? "receive" : "transmit", msg->addr, msg->len, stop);
317 
318 	priv->len = msg->len;
319 	priv->buf = msg->buf;
320 	priv->enabled_irqs = UNIPHIER_FI2C_INT_FAULTS;
321 	priv->error = 0;
322 	priv->flags = 0;
323 
324 	if (stop)
325 		priv->flags |= UNIPHIER_FI2C_STOP;
326 
327 	reinit_completion(&priv->comp);
328 	uniphier_fi2c_clear_irqs(priv);
329 	writel(UNIPHIER_FI2C_RST_TBRST | UNIPHIER_FI2C_RST_RBRST,
330 	       priv->membase + UNIPHIER_FI2C_RST);	/* reset TX/RX FIFO */
331 
332 	if (is_read)
333 		uniphier_fi2c_rx_init(priv, msg->addr);
334 	else
335 		uniphier_fi2c_tx_init(priv, msg->addr);
336 
337 	uniphier_fi2c_set_irqs(priv);
338 
339 	dev_dbg(&adap->dev, "start condition\n");
340 	writel(UNIPHIER_FI2C_CR_MST | UNIPHIER_FI2C_CR_STA,
341 	       priv->membase + UNIPHIER_FI2C_CR);
342 
343 	time_left = wait_for_completion_timeout(&priv->comp, adap->timeout);
344 	if (!time_left) {
345 		dev_err(&adap->dev, "transaction timeout.\n");
346 		uniphier_fi2c_recover(priv);
347 		return -ETIMEDOUT;
348 	}
349 	dev_dbg(&adap->dev, "complete\n");
350 
351 	if (unlikely(priv->flags & UNIPHIER_FI2C_DEFER_STOP_COMP)) {
352 		u32 status;
353 		int ret;
354 
355 		ret = readl_poll_timeout(priv->membase + UNIPHIER_FI2C_SR,
356 					 status,
357 					 (status & UNIPHIER_FI2C_SR_STS) &&
358 					 !(status & UNIPHIER_FI2C_SR_BB),
359 					 1, 20);
360 		if (ret) {
361 			dev_err(&adap->dev,
362 				"stop condition was not completed.\n");
363 			uniphier_fi2c_recover(priv);
364 			return ret;
365 		}
366 	}
367 
368 	return priv->error;
369 }
370 
371 static int uniphier_fi2c_check_bus_busy(struct i2c_adapter *adap)
372 {
373 	struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);
374 
375 	if (readl(priv->membase + UNIPHIER_FI2C_SR) & UNIPHIER_FI2C_SR_DB) {
376 		if (priv->busy_cnt++ > 3) {
377 			/*
378 			 * If bus busy continues too long, it is probably
379 			 * in a wrong state.  Try bus recovery.
380 			 */
381 			uniphier_fi2c_recover(priv);
382 			priv->busy_cnt = 0;
383 		}
384 
385 		return -EAGAIN;
386 	}
387 
388 	priv->busy_cnt = 0;
389 	return 0;
390 }
391 
392 static int uniphier_fi2c_master_xfer(struct i2c_adapter *adap,
393 				     struct i2c_msg *msgs, int num)
394 {
395 	struct i2c_msg *msg, *emsg = msgs + num;
396 	int ret;
397 
398 	ret = uniphier_fi2c_check_bus_busy(adap);
399 	if (ret)
400 		return ret;
401 
402 	for (msg = msgs; msg < emsg; msg++) {
403 		/* If next message is read, skip the stop condition */
404 		bool stop = !(msg + 1 < emsg && msg[1].flags & I2C_M_RD);
405 		/* but, force it if I2C_M_STOP is set */
406 		if (msg->flags & I2C_M_STOP)
407 			stop = true;
408 
409 		ret = uniphier_fi2c_master_xfer_one(adap, msg, stop);
410 		if (ret)
411 			return ret;
412 	}
413 
414 	return num;
415 }
416 
417 static u32 uniphier_fi2c_functionality(struct i2c_adapter *adap)
418 {
419 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
420 }
421 
422 static const struct i2c_algorithm uniphier_fi2c_algo = {
423 	.master_xfer = uniphier_fi2c_master_xfer,
424 	.functionality = uniphier_fi2c_functionality,
425 };
426 
427 static int uniphier_fi2c_get_scl(struct i2c_adapter *adap)
428 {
429 	struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);
430 
431 	return !!(readl(priv->membase + UNIPHIER_FI2C_BM) &
432 							UNIPHIER_FI2C_BM_SCLS);
433 }
434 
435 static void uniphier_fi2c_set_scl(struct i2c_adapter *adap, int val)
436 {
437 	struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);
438 
439 	writel(val ? UNIPHIER_FI2C_BRST_RSCL : 0,
440 	       priv->membase + UNIPHIER_FI2C_BRST);
441 }
442 
443 static int uniphier_fi2c_get_sda(struct i2c_adapter *adap)
444 {
445 	struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);
446 
447 	return !!(readl(priv->membase + UNIPHIER_FI2C_BM) &
448 							UNIPHIER_FI2C_BM_SDAS);
449 }
450 
451 static void uniphier_fi2c_unprepare_recovery(struct i2c_adapter *adap)
452 {
453 	uniphier_fi2c_prepare_operation(i2c_get_adapdata(adap));
454 }
455 
456 static struct i2c_bus_recovery_info uniphier_fi2c_bus_recovery_info = {
457 	.recover_bus = i2c_generic_scl_recovery,
458 	.get_scl = uniphier_fi2c_get_scl,
459 	.set_scl = uniphier_fi2c_set_scl,
460 	.get_sda = uniphier_fi2c_get_sda,
461 	.unprepare_recovery = uniphier_fi2c_unprepare_recovery,
462 };
463 
464 static void uniphier_fi2c_hw_init(struct uniphier_fi2c_priv *priv,
465 				  u32 bus_speed, unsigned long clk_rate)
466 {
467 	u32 tmp;
468 
469 	tmp = readl(priv->membase + UNIPHIER_FI2C_CR);
470 	tmp |= UNIPHIER_FI2C_CR_MST;
471 	writel(tmp, priv->membase + UNIPHIER_FI2C_CR);
472 
473 	uniphier_fi2c_reset(priv);
474 
475 	tmp = clk_rate / bus_speed;
476 
477 	writel(tmp, priv->membase + UNIPHIER_FI2C_CYC);
478 	writel(tmp / 2, priv->membase + UNIPHIER_FI2C_LCTL);
479 	writel(tmp / 2, priv->membase + UNIPHIER_FI2C_SSUT);
480 	writel(tmp / 16, priv->membase + UNIPHIER_FI2C_DSUT);
481 
482 	uniphier_fi2c_prepare_operation(priv);
483 }
484 
485 static int uniphier_fi2c_probe(struct platform_device *pdev)
486 {
487 	struct device *dev = &pdev->dev;
488 	struct uniphier_fi2c_priv *priv;
489 	struct resource *regs;
490 	u32 bus_speed;
491 	unsigned long clk_rate;
492 	int irq, ret;
493 
494 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
495 	if (!priv)
496 		return -ENOMEM;
497 
498 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
499 	priv->membase = devm_ioremap_resource(dev, regs);
500 	if (IS_ERR(priv->membase))
501 		return PTR_ERR(priv->membase);
502 
503 	irq = platform_get_irq(pdev, 0);
504 	if (irq < 0) {
505 		dev_err(dev, "failed to get IRQ number\n");
506 		return irq;
507 	}
508 
509 	if (of_property_read_u32(dev->of_node, "clock-frequency", &bus_speed))
510 		bus_speed = UNIPHIER_FI2C_DEFAULT_SPEED;
511 
512 	if (!bus_speed || bus_speed > UNIPHIER_FI2C_MAX_SPEED) {
513 		dev_err(dev, "invalid clock-frequency %d\n", bus_speed);
514 		return -EINVAL;
515 	}
516 
517 	priv->clk = devm_clk_get(dev, NULL);
518 	if (IS_ERR(priv->clk)) {
519 		dev_err(dev, "failed to get clock\n");
520 		return PTR_ERR(priv->clk);
521 	}
522 
523 	ret = clk_prepare_enable(priv->clk);
524 	if (ret)
525 		return ret;
526 
527 	clk_rate = clk_get_rate(priv->clk);
528 	if (!clk_rate) {
529 		dev_err(dev, "input clock rate should not be zero\n");
530 		ret = -EINVAL;
531 		goto disable_clk;
532 	}
533 
534 	init_completion(&priv->comp);
535 	priv->adap.owner = THIS_MODULE;
536 	priv->adap.algo = &uniphier_fi2c_algo;
537 	priv->adap.dev.parent = dev;
538 	priv->adap.dev.of_node = dev->of_node;
539 	strlcpy(priv->adap.name, "UniPhier FI2C", sizeof(priv->adap.name));
540 	priv->adap.bus_recovery_info = &uniphier_fi2c_bus_recovery_info;
541 	i2c_set_adapdata(&priv->adap, priv);
542 	platform_set_drvdata(pdev, priv);
543 
544 	uniphier_fi2c_hw_init(priv, bus_speed, clk_rate);
545 
546 	ret = devm_request_irq(dev, irq, uniphier_fi2c_interrupt, 0,
547 			       pdev->name, priv);
548 	if (ret) {
549 		dev_err(dev, "failed to request irq %d\n", irq);
550 		goto disable_clk;
551 	}
552 
553 	ret = i2c_add_adapter(&priv->adap);
554 disable_clk:
555 	if (ret)
556 		clk_disable_unprepare(priv->clk);
557 
558 	return ret;
559 }
560 
561 static int uniphier_fi2c_remove(struct platform_device *pdev)
562 {
563 	struct uniphier_fi2c_priv *priv = platform_get_drvdata(pdev);
564 
565 	i2c_del_adapter(&priv->adap);
566 	clk_disable_unprepare(priv->clk);
567 
568 	return 0;
569 }
570 
571 static const struct of_device_id uniphier_fi2c_match[] = {
572 	{ .compatible = "socionext,uniphier-fi2c" },
573 	{ /* sentinel */ }
574 };
575 MODULE_DEVICE_TABLE(of, uniphier_fi2c_match);
576 
577 static struct platform_driver uniphier_fi2c_drv = {
578 	.probe  = uniphier_fi2c_probe,
579 	.remove = uniphier_fi2c_remove,
580 	.driver = {
581 		.name  = "uniphier-fi2c",
582 		.of_match_table = uniphier_fi2c_match,
583 	},
584 };
585 module_platform_driver(uniphier_fi2c_drv);
586 
587 MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
588 MODULE_DESCRIPTION("UniPhier FIFO-builtin I2C bus driver");
589 MODULE_LICENSE("GPL");
590