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i2c-synquacer.c

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linux-6.19.14/drivers/i2c/busses/i2c-synquacer.c C
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (C) 2012 FUJITSU SEMICONDUCTOR LIMITED
  4 */
  5
  6#include <linux/acpi.h>
  7#include <linux/clk.h>
  8#include <linux/delay.h>
  9#include <linux/device.h>
 10#include <linux/err.h>
 11#include <linux/errno.h>
 12#include <linux/i2c.h>
 13#include <linux/interrupt.h>
 14#include <linux/io.h>
 15#include <linux/kernel.h>
 16#include <linux/module.h>
 17#include <linux/platform_device.h>
 18#include <linux/sched.h>
 19#include <linux/slab.h>
 20#include <linux/spinlock.h>
 21
 22#define WAIT_PCLK(n, rate)	\
 23	ndelay(DIV_ROUND_UP(DIV_ROUND_UP(1000000000, rate), n) + 10)
 24
 25/* I2C register address definitions */
 26#define SYNQUACER_I2C_REG_BSR		(0x00 << 2) // Bus Status
 27#define SYNQUACER_I2C_REG_BCR		(0x01 << 2) // Bus Control
 28#define SYNQUACER_I2C_REG_CCR		(0x02 << 2) // Clock Control
 29#define SYNQUACER_I2C_REG_ADR		(0x03 << 2) // Address
 30#define SYNQUACER_I2C_REG_DAR		(0x04 << 2) // Data
 31#define SYNQUACER_I2C_REG_CSR		(0x05 << 2) // Expansion CS
 32#define SYNQUACER_I2C_REG_FSR		(0x06 << 2) // Bus Clock Freq
 33#define SYNQUACER_I2C_REG_BC2R		(0x07 << 2) // Bus Control 2
 34
 35/* I2C register bit definitions */
 36#define SYNQUACER_I2C_BSR_FBT		BIT(0)	// First Byte Transfer
 37#define SYNQUACER_I2C_BSR_GCA		BIT(1)	// General Call Address
 38#define SYNQUACER_I2C_BSR_AAS		BIT(2)	// Address as Slave
 39#define SYNQUACER_I2C_BSR_TRX		BIT(3)	// Transfer/Receive
 40#define SYNQUACER_I2C_BSR_LRB		BIT(4)	// Last Received Bit
 41#define SYNQUACER_I2C_BSR_AL		BIT(5)	// Arbitration Lost
 42#define SYNQUACER_I2C_BSR_RSC		BIT(6)	// Repeated Start Cond.
 43#define SYNQUACER_I2C_BSR_BB		BIT(7)	// Bus Busy
 44
 45#define SYNQUACER_I2C_BCR_INT		BIT(0)	// Interrupt
 46#define SYNQUACER_I2C_BCR_INTE		BIT(1)	// Interrupt Enable
 47#define SYNQUACER_I2C_BCR_GCAA		BIT(2)	// Gen. Call Access Ack.
 48#define SYNQUACER_I2C_BCR_ACK		BIT(3)	// Acknowledge
 49#define SYNQUACER_I2C_BCR_MSS		BIT(4)	// Master Slave Select
 50#define SYNQUACER_I2C_BCR_SCC		BIT(5)	// Start Condition Cont.
 51#define SYNQUACER_I2C_BCR_BEIE		BIT(6)	// Bus Error Int Enable
 52#define SYNQUACER_I2C_BCR_BER		BIT(7)	// Bus Error
 53
 54#define SYNQUACER_I2C_CCR_CS_MASK	(0x1f)	// CCR Clock Period Sel.
 55#define SYNQUACER_I2C_CCR_EN		BIT(5)	// Enable
 56#define SYNQUACER_I2C_CCR_FM		BIT(6)	// Speed Mode Select
 57
 58#define SYNQUACER_I2C_CSR_CS_MASK	(0x3f)	// CSR Clock Period Sel.
 59
 60#define SYNQUACER_I2C_BC2R_SCLL		BIT(0)	// SCL Low Drive
 61#define SYNQUACER_I2C_BC2R_SDAL		BIT(1)	// SDA Low Drive
 62#define SYNQUACER_I2C_BC2R_SCLS		BIT(4)	// SCL Status
 63#define SYNQUACER_I2C_BC2R_SDAS		BIT(5)	// SDA Status
 64
 65/* PCLK frequency */
 66#define SYNQUACER_I2C_BUS_CLK_FR(rate)	(((rate) / 20000000) + 1)
 67
 68/* STANDARD MODE frequency */
 69#define SYNQUACER_I2C_CLK_MASTER_STD(rate)			\
 70	DIV_ROUND_UP(DIV_ROUND_UP((rate), I2C_MAX_STANDARD_MODE_FREQ) - 2, 2)
 71/* FAST MODE frequency */
 72#define SYNQUACER_I2C_CLK_MASTER_FAST(rate)			\
 73	DIV_ROUND_UP((DIV_ROUND_UP((rate), I2C_MAX_FAST_MODE_FREQ) - 2) * 2, 3)
 74
 75/* (clkrate <= 18000000) */
 76/* calculate the value of CS bits in CCR register on standard mode */
 77#define SYNQUACER_I2C_CCR_CS_STD_MAX_18M(rate)			\
 78	   ((SYNQUACER_I2C_CLK_MASTER_STD(rate) - 65)		\
 79					& SYNQUACER_I2C_CCR_CS_MASK)
 80
 81/* calculate the value of CS bits in CSR register on standard mode */
 82#define SYNQUACER_I2C_CSR_CS_STD_MAX_18M(rate)		0x00
 83
 84/* calculate the value of CS bits in CCR register on fast mode */
 85#define SYNQUACER_I2C_CCR_CS_FAST_MAX_18M(rate)			\
 86	   ((SYNQUACER_I2C_CLK_MASTER_FAST(rate) - 1)		\
 87					& SYNQUACER_I2C_CCR_CS_MASK)
 88
 89/* calculate the value of CS bits in CSR register on fast mode */
 90#define SYNQUACER_I2C_CSR_CS_FAST_MAX_18M(rate)		0x00
 91
 92/* (clkrate > 18000000) */
 93/* calculate the value of CS bits in CCR register on standard mode */
 94#define SYNQUACER_I2C_CCR_CS_STD_MIN_18M(rate)			\
 95	   ((SYNQUACER_I2C_CLK_MASTER_STD(rate) - 1)		\
 96					& SYNQUACER_I2C_CCR_CS_MASK)
 97
 98/* calculate the value of CS bits in CSR register on standard mode */
 99#define SYNQUACER_I2C_CSR_CS_STD_MIN_18M(rate)			\
100	   (((SYNQUACER_I2C_CLK_MASTER_STD(rate) - 1) >> 5)	\
101					& SYNQUACER_I2C_CSR_CS_MASK)
102
103/* calculate the value of CS bits in CCR register on fast mode */
104#define SYNQUACER_I2C_CCR_CS_FAST_MIN_18M(rate)			\
105	   ((SYNQUACER_I2C_CLK_MASTER_FAST(rate) - 1)		\
106					& SYNQUACER_I2C_CCR_CS_MASK)
107
108/* calculate the value of CS bits in CSR register on fast mode */
109#define SYNQUACER_I2C_CSR_CS_FAST_MIN_18M(rate)			\
110	   (((SYNQUACER_I2C_CLK_MASTER_FAST(rate) - 1) >> 5)	\
111					& SYNQUACER_I2C_CSR_CS_MASK)
112
113/* min I2C clock frequency 14M */
114#define SYNQUACER_I2C_MIN_CLK_RATE	(14 * 1000000)
115/* max I2C clock frequency 200M */
116#define SYNQUACER_I2C_MAX_CLK_RATE	(200 * 1000000)
117/* I2C clock frequency 18M */
118#define SYNQUACER_I2C_CLK_RATE_18M	(18 * 1000000)
119
120#define SYNQUACER_I2C_SPEED_FM		400	// Fast Mode
121#define SYNQUACER_I2C_SPEED_SM		100	// Standard Mode
122
123enum i2c_state {
124	STATE_IDLE,
125	STATE_START,
126	STATE_READ,
127	STATE_WRITE
128};
129
130struct synquacer_i2c {
131	struct completion	completion;
132
133	struct i2c_msg		*msg;
134	u32			msg_num;
135	u32			msg_idx;
136	u32			msg_ptr;
137
138	int			irq;
139	struct device		*dev;
140	void __iomem		*base;
141	u32			pclkrate;
142	u32			speed_khz;
143	u32			timeout_ms;
144	enum i2c_state		state;
145	struct i2c_adapter	adapter;
146};
147
148static inline int is_lastmsg(struct synquacer_i2c *i2c)
149{
150	return i2c->msg_idx >= (i2c->msg_num - 1);
151}
152
153static inline int is_msglast(struct synquacer_i2c *i2c)
154{
155	return i2c->msg_ptr == (i2c->msg->len - 1);
156}
157
158static inline int is_msgend(struct synquacer_i2c *i2c)
159{
160	return i2c->msg_ptr >= i2c->msg->len;
161}
162
163static inline unsigned long calc_timeout_ms(struct synquacer_i2c *i2c,
164					    struct i2c_msg *msgs,
165					    int num)
166{
167	unsigned long bit_count = 0;
168	int i;
169
170	for (i = 0; i < num; i++, msgs++)
171		bit_count += msgs->len;
172
173	return DIV_ROUND_UP((bit_count * 9 + num * 10) * 3, 200) + 10;
174}
175
176static void synquacer_i2c_stop(struct synquacer_i2c *i2c, int ret)
177{
178	/*
179	 * clear IRQ (INT=0, BER=0)
180	 * set Stop Condition (MSS=0)
181	 * Interrupt Disable
182	 */
183	writeb(0, i2c->base + SYNQUACER_I2C_REG_BCR);
184
185	i2c->state = STATE_IDLE;
186
187	i2c->msg_ptr = 0;
188	i2c->msg = NULL;
189	i2c->msg_idx++;
190	i2c->msg_num = 0;
191	if (ret)
192		i2c->msg_idx = ret;
193
194	complete(&i2c->completion);
195}
196
197static void synquacer_i2c_hw_init(struct synquacer_i2c *i2c)
198{
199	unsigned char ccr_cs, csr_cs;
200	u32 rt = i2c->pclkrate;
201
202	/* Set own Address */
203	writeb(0, i2c->base + SYNQUACER_I2C_REG_ADR);
204
205	/* Set PCLK frequency */
206	writeb(SYNQUACER_I2C_BUS_CLK_FR(i2c->pclkrate),
207	       i2c->base + SYNQUACER_I2C_REG_FSR);
208
209	switch (i2c->speed_khz) {
210	case SYNQUACER_I2C_SPEED_FM:
211		if (i2c->pclkrate <= SYNQUACER_I2C_CLK_RATE_18M) {
212			ccr_cs = SYNQUACER_I2C_CCR_CS_FAST_MAX_18M(rt);
213			csr_cs = SYNQUACER_I2C_CSR_CS_FAST_MAX_18M(rt);
214		} else {
215			ccr_cs = SYNQUACER_I2C_CCR_CS_FAST_MIN_18M(rt);
216			csr_cs = SYNQUACER_I2C_CSR_CS_FAST_MIN_18M(rt);
217		}
218
219		/* Set Clock and enable, Set fast mode */
220		writeb(ccr_cs | SYNQUACER_I2C_CCR_FM |
221		       SYNQUACER_I2C_CCR_EN,
222		       i2c->base + SYNQUACER_I2C_REG_CCR);
223		writeb(csr_cs, i2c->base + SYNQUACER_I2C_REG_CSR);
224		break;
225	case SYNQUACER_I2C_SPEED_SM:
226		if (i2c->pclkrate <= SYNQUACER_I2C_CLK_RATE_18M) {
227			ccr_cs = SYNQUACER_I2C_CCR_CS_STD_MAX_18M(rt);
228			csr_cs = SYNQUACER_I2C_CSR_CS_STD_MAX_18M(rt);
229		} else {
230			ccr_cs = SYNQUACER_I2C_CCR_CS_STD_MIN_18M(rt);
231			csr_cs = SYNQUACER_I2C_CSR_CS_STD_MIN_18M(rt);
232		}
233
234		/* Set Clock and enable, Set standard mode */
235		writeb(ccr_cs | SYNQUACER_I2C_CCR_EN,
236		      i2c->base + SYNQUACER_I2C_REG_CCR);
237		writeb(csr_cs, i2c->base + SYNQUACER_I2C_REG_CSR);
238		break;
239	default:
240		WARN_ON(1);
241	}
242
243	/* clear IRQ (INT=0, BER=0), Interrupt Disable */
244	writeb(0, i2c->base + SYNQUACER_I2C_REG_BCR);
245	writeb(0, i2c->base + SYNQUACER_I2C_REG_BC2R);
246}
247
248static void synquacer_i2c_hw_reset(struct synquacer_i2c *i2c)
249{
250	/* Disable clock */
251	writeb(0, i2c->base + SYNQUACER_I2C_REG_CCR);
252	writeb(0, i2c->base + SYNQUACER_I2C_REG_CSR);
253
254	WAIT_PCLK(100, i2c->pclkrate);
255}
256
257static int synquacer_i2c_master_start(struct synquacer_i2c *i2c,
258				      struct i2c_msg *pmsg)
259{
260	unsigned char bsr, bcr;
261
262	writeb(i2c_8bit_addr_from_msg(pmsg), i2c->base + SYNQUACER_I2C_REG_DAR);
263
264	dev_dbg(i2c->dev, "slave:0x%02x\n", pmsg->addr);
265
266	/* Generate Start Condition */
267	bsr = readb(i2c->base + SYNQUACER_I2C_REG_BSR);
268	bcr = readb(i2c->base + SYNQUACER_I2C_REG_BCR);
269	dev_dbg(i2c->dev, "bsr:0x%02x, bcr:0x%02x\n", bsr, bcr);
270
271	if ((bsr & SYNQUACER_I2C_BSR_BB) &&
272	    !(bcr & SYNQUACER_I2C_BCR_MSS)) {
273		dev_dbg(i2c->dev, "bus is busy");
274		return -EBUSY;
275	}
276
277	if (bsr & SYNQUACER_I2C_BSR_BB) { /* Bus is busy */
278		dev_dbg(i2c->dev, "Continuous Start");
279		writeb(bcr | SYNQUACER_I2C_BCR_SCC,
280		       i2c->base + SYNQUACER_I2C_REG_BCR);
281	} else {
282		if (bcr & SYNQUACER_I2C_BCR_MSS) {
283			dev_dbg(i2c->dev, "not in master mode");
284			return -EAGAIN;
285		}
286		dev_dbg(i2c->dev, "Start Condition");
287		/* Start Condition + Enable Interrupts */
288		writeb(bcr | SYNQUACER_I2C_BCR_MSS |
289		       SYNQUACER_I2C_BCR_INTE | SYNQUACER_I2C_BCR_BEIE,
290		       i2c->base + SYNQUACER_I2C_REG_BCR);
291	}
292
293	WAIT_PCLK(10, i2c->pclkrate);
294
295	/* get BSR & BCR registers */
296	bsr = readb(i2c->base + SYNQUACER_I2C_REG_BSR);
297	bcr = readb(i2c->base + SYNQUACER_I2C_REG_BCR);
298	dev_dbg(i2c->dev, "bsr:0x%02x, bcr:0x%02x\n", bsr, bcr);
299
300	if ((bsr & SYNQUACER_I2C_BSR_AL) ||
301	    !(bcr & SYNQUACER_I2C_BCR_MSS)) {
302		dev_dbg(i2c->dev, "arbitration lost\n");
303		return -EAGAIN;
304	}
305
306	return 0;
307}
308
309static int synquacer_i2c_doxfer(struct synquacer_i2c *i2c,
310				struct i2c_msg *msgs, int num)
311{
312	unsigned char bsr;
313	unsigned long time_left;
314	int ret;
315
316	synquacer_i2c_hw_init(i2c);
317	bsr = readb(i2c->base + SYNQUACER_I2C_REG_BSR);
318	if (bsr & SYNQUACER_I2C_BSR_BB) {
319		dev_err(i2c->dev, "cannot get bus (bus busy)\n");
320		return -EBUSY;
321	}
322
323	reinit_completion(&i2c->completion);
324
325	i2c->msg = msgs;
326	i2c->msg_num = num;
327	i2c->msg_ptr = 0;
328	i2c->msg_idx = 0;
329	i2c->state = STATE_START;
330
331	ret = synquacer_i2c_master_start(i2c, i2c->msg);
332	if (ret < 0) {
333		dev_dbg(i2c->dev, "Address failed: (%d)\n", ret);
334		return ret;
335	}
336
337	time_left = wait_for_completion_timeout(&i2c->completion,
338						msecs_to_jiffies(i2c->timeout_ms));
339	if (time_left == 0) {
340		dev_dbg(i2c->dev, "timeout\n");
341		return -EAGAIN;
342	}
343
344	ret = i2c->msg_idx;
345	if (ret != num) {
346		dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret);
347		return -EAGAIN;
348	}
349
350	/* wait 2 clock periods to ensure the stop has been through the bus */
351	udelay(DIV_ROUND_UP(2 * 1000, i2c->speed_khz));
352
353	return ret;
354}
355
356static irqreturn_t synquacer_i2c_isr(int irq, void *dev_id)
357{
358	struct synquacer_i2c *i2c = dev_id;
359
360	unsigned char byte;
361	unsigned char bsr, bcr;
362	int ret;
363
364	bcr = readb(i2c->base + SYNQUACER_I2C_REG_BCR);
365	bsr = readb(i2c->base + SYNQUACER_I2C_REG_BSR);
366	dev_dbg(i2c->dev, "bsr:0x%02x, bcr:0x%02x\n", bsr, bcr);
367
368	if (bcr & SYNQUACER_I2C_BCR_BER) {
369		dev_err(i2c->dev, "bus error\n");
370		synquacer_i2c_stop(i2c, -EAGAIN);
371		goto out;
372	}
373	if ((bsr & SYNQUACER_I2C_BSR_AL) ||
374	    !(bcr & SYNQUACER_I2C_BCR_MSS)) {
375		dev_dbg(i2c->dev, "arbitration lost\n");
376		synquacer_i2c_stop(i2c, -EAGAIN);
377		goto out;
378	}
379
380	switch (i2c->state) {
381	case STATE_START:
382		if (bsr & SYNQUACER_I2C_BSR_LRB) {
383			dev_dbg(i2c->dev, "ack was not received\n");
384			synquacer_i2c_stop(i2c, -EAGAIN);
385			goto out;
386		}
387
388		if (i2c->msg->flags & I2C_M_RD)
389			i2c->state = STATE_READ;
390		else
391			i2c->state = STATE_WRITE;
392
393		if (is_lastmsg(i2c) && i2c->msg->len == 0) {
394			synquacer_i2c_stop(i2c, 0);
395			goto out;
396		}
397
398		if (i2c->state == STATE_READ)
399			goto prepare_read;
400		fallthrough;
401
402	case STATE_WRITE:
403		if (bsr & SYNQUACER_I2C_BSR_LRB) {
404			dev_dbg(i2c->dev, "WRITE: No Ack\n");
405			synquacer_i2c_stop(i2c, -EAGAIN);
406			goto out;
407		}
408
409		if (!is_msgend(i2c)) {
410			writeb(i2c->msg->buf[i2c->msg_ptr++],
411			       i2c->base + SYNQUACER_I2C_REG_DAR);
412
413			/* clear IRQ, and continue */
414			writeb(SYNQUACER_I2C_BCR_BEIE |
415			       SYNQUACER_I2C_BCR_MSS |
416			       SYNQUACER_I2C_BCR_INTE,
417			       i2c->base + SYNQUACER_I2C_REG_BCR);
418			break;
419		}
420		if (is_lastmsg(i2c)) {
421			synquacer_i2c_stop(i2c, 0);
422			break;
423		}
424		dev_dbg(i2c->dev, "WRITE: Next Message\n");
425
426		i2c->msg_ptr = 0;
427		i2c->msg_idx++;
428		i2c->msg++;
429
430		/* send the new start */
431		ret = synquacer_i2c_master_start(i2c, i2c->msg);
432		if (ret < 0) {
433			dev_dbg(i2c->dev, "restart error (%d)\n", ret);
434			synquacer_i2c_stop(i2c, -EAGAIN);
435			break;
436		}
437		i2c->state = STATE_START;
438		break;
439
440	case STATE_READ:
441		byte = readb(i2c->base + SYNQUACER_I2C_REG_DAR);
442		if (!(bsr & SYNQUACER_I2C_BSR_FBT)) /* data */
443			i2c->msg->buf[i2c->msg_ptr++] = byte;
444		else /* address */
445			dev_dbg(i2c->dev, "address:0x%02x. ignore it.\n", byte);
446
447prepare_read:
448		if (is_msglast(i2c)) {
449			writeb(SYNQUACER_I2C_BCR_MSS |
450			       SYNQUACER_I2C_BCR_BEIE |
451			       SYNQUACER_I2C_BCR_INTE,
452			       i2c->base + SYNQUACER_I2C_REG_BCR);
453			break;
454		}
455		if (!is_msgend(i2c)) {
456			writeb(SYNQUACER_I2C_BCR_MSS |
457			       SYNQUACER_I2C_BCR_BEIE |
458			       SYNQUACER_I2C_BCR_INTE |
459			       SYNQUACER_I2C_BCR_ACK,
460			       i2c->base + SYNQUACER_I2C_REG_BCR);
461			break;
462		}
463		if (is_lastmsg(i2c)) {
464			/* last message, send stop and complete */
465			dev_dbg(i2c->dev, "READ: Send Stop\n");
466			synquacer_i2c_stop(i2c, 0);
467			break;
468		}
469		dev_dbg(i2c->dev, "READ: Next Transfer\n");
470
471		i2c->msg_ptr = 0;
472		i2c->msg_idx++;
473		i2c->msg++;
474
475		ret = synquacer_i2c_master_start(i2c, i2c->msg);
476		if (ret < 0) {
477			dev_dbg(i2c->dev, "restart error (%d)\n", ret);
478			synquacer_i2c_stop(i2c, -EAGAIN);
479		} else {
480			i2c->state = STATE_START;
481		}
482		break;
483	default:
484		dev_err(i2c->dev, "called in err STATE (%d)\n", i2c->state);
485		break;
486	}
487
488out:
489	WAIT_PCLK(10, i2c->pclkrate);
490	return IRQ_HANDLED;
491}
492
493static int synquacer_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
494			      int num)
495{
496	struct synquacer_i2c *i2c;
497	int retry;
498	int ret;
499
500	i2c = i2c_get_adapdata(adap);
501	i2c->timeout_ms = calc_timeout_ms(i2c, msgs, num);
502
503	dev_dbg(i2c->dev, "calculated timeout %d ms\n", i2c->timeout_ms);
504
505	for (retry = 0; retry <= adap->retries; retry++) {
506		ret = synquacer_i2c_doxfer(i2c, msgs, num);
507		if (ret != -EAGAIN)
508			return ret;
509
510		dev_dbg(i2c->dev, "Retrying transmission (%d)\n", retry);
511
512		synquacer_i2c_hw_reset(i2c);
513	}
514	return -EIO;
515}
516
517static u32 synquacer_i2c_functionality(struct i2c_adapter *adap)
518{
519	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
520}
521
522static const struct i2c_algorithm synquacer_i2c_algo = {
523	.xfer = synquacer_i2c_xfer,
524	.functionality = synquacer_i2c_functionality,
525};
526
527static const struct i2c_adapter synquacer_i2c_ops = {
528	.owner		= THIS_MODULE,
529	.name		= "synquacer_i2c-adapter",
530	.algo		= &synquacer_i2c_algo,
531	.retries	= 5,
532};
533
534static int synquacer_i2c_probe(struct platform_device *pdev)
535{
536	struct synquacer_i2c *i2c;
537	struct clk *pclk;
538	u32 bus_speed;
539	int ret;
540
541	i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
542	if (!i2c)
543		return -ENOMEM;
544
545	bus_speed = i2c_acpi_find_bus_speed(&pdev->dev);
546	if (!bus_speed)
547		device_property_read_u32(&pdev->dev, "clock-frequency",
548					 &bus_speed);
549
550	device_property_read_u32(&pdev->dev, "socionext,pclk-rate",
551				 &i2c->pclkrate);
552
553	pclk = devm_clk_get_optional_enabled(&pdev->dev, "pclk");
554	if (IS_ERR(pclk))
555		return dev_err_probe(&pdev->dev, PTR_ERR(pclk),
556				     "failed to get and enable clock\n");
557
558	if (pclk)
559		i2c->pclkrate = clk_get_rate(pclk);
560
561	if (i2c->pclkrate < SYNQUACER_I2C_MIN_CLK_RATE ||
562	    i2c->pclkrate > SYNQUACER_I2C_MAX_CLK_RATE)
563		return dev_err_probe(&pdev->dev, -EINVAL,
564				     "PCLK missing or out of range (%d)\n",
565				     i2c->pclkrate);
566
567	i2c->base = devm_platform_ioremap_resource(pdev, 0);
568	if (IS_ERR(i2c->base))
569		return PTR_ERR(i2c->base);
570
571	i2c->irq = platform_get_irq(pdev, 0);
572	if (i2c->irq < 0)
573		return i2c->irq;
574
575	ret = devm_request_irq(&pdev->dev, i2c->irq, synquacer_i2c_isr,
576			       0, dev_name(&pdev->dev), i2c);
577	if (ret < 0)
578		return dev_err_probe(&pdev->dev, ret, "cannot claim IRQ %d\n", i2c->irq);
579
580	i2c->state = STATE_IDLE;
581	i2c->dev = &pdev->dev;
582	i2c->adapter = synquacer_i2c_ops;
583	i2c_set_adapdata(&i2c->adapter, i2c);
584	i2c->adapter.dev.parent = &pdev->dev;
585	i2c->adapter.dev.of_node = pdev->dev.of_node;
586	ACPI_COMPANION_SET(&i2c->adapter.dev, ACPI_COMPANION(&pdev->dev));
587	i2c->adapter.nr = pdev->id;
588	init_completion(&i2c->completion);
589
590	if (bus_speed < I2C_MAX_FAST_MODE_FREQ)
591		i2c->speed_khz = SYNQUACER_I2C_SPEED_SM;
592	else
593		i2c->speed_khz = SYNQUACER_I2C_SPEED_FM;
594
595	synquacer_i2c_hw_init(i2c);
596
597	ret = i2c_add_numbered_adapter(&i2c->adapter);
598	if (ret)
599		return dev_err_probe(&pdev->dev, ret, "failed to add bus to i2c core\n");
600
601	platform_set_drvdata(pdev, i2c);
602
603	dev_info(&pdev->dev, "%s: synquacer_i2c adapter\n",
604		 dev_name(&i2c->adapter.dev));
605
606	return 0;
607}
608
609static void synquacer_i2c_remove(struct platform_device *pdev)
610{
611	struct synquacer_i2c *i2c = platform_get_drvdata(pdev);
612
613	i2c_del_adapter(&i2c->adapter);
614};
615
616static const struct of_device_id synquacer_i2c_dt_ids[] __maybe_unused = {
617	{ .compatible = "socionext,synquacer-i2c" },
618	{ /* sentinel */ }
619};
620MODULE_DEVICE_TABLE(of, synquacer_i2c_dt_ids);
621
622#ifdef CONFIG_ACPI
623static const struct acpi_device_id synquacer_i2c_acpi_ids[] = {
624	{ "SCX0003" },
625	{ /* sentinel */ }
626};
627MODULE_DEVICE_TABLE(acpi, synquacer_i2c_acpi_ids);
628#endif
629
630static struct platform_driver synquacer_i2c_driver = {
631	.probe	= synquacer_i2c_probe,
632	.remove = synquacer_i2c_remove,
633	.driver	= {
634		.name = "synquacer_i2c",
635		.of_match_table = of_match_ptr(synquacer_i2c_dt_ids),
636		.acpi_match_table = ACPI_PTR(synquacer_i2c_acpi_ids),
637	},
638};
639module_platform_driver(synquacer_i2c_driver);
640
641MODULE_AUTHOR("Fujitsu Semiconductor Ltd");
642MODULE_DESCRIPTION("Socionext SynQuacer I2C Driver");
643MODULE_LICENSE("GPL v2");
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