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Kuninori Morimoto6ccbe602012-09-27 23:44:25 -07001/*
Wolfram Sang3d99bea2014-05-28 09:44:46 +02002 * Driver for the Renesas RCar I2C unit
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -07003 *
Wolfram Sang3d99bea2014-05-28 09:44:46 +02004 * Copyright (C) 2014 Wolfram Sang <wsa@sang-engineering.com>
5 *
6 * Copyright (C) 2012-14 Renesas Solutions Corp.
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -07007 * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
8 *
9 * This file is based on the drivers/i2c/busses/i2c-sh7760.c
10 * (c) 2005-2008 MSC Vertriebsges.m.b.H, Manuel Lauss <mlau@msc-ge.com>
11 *
12 * This file used out-of-tree driver i2c-rcar.c
13 * Copyright (C) 2011-2012 Renesas Electronics Corporation
14 *
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License as published by
Wolfram Sang3d99bea2014-05-28 09:44:46 +020017 * the Free Software Foundation; version 2 of the License.
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -070018 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -070023 */
24#include <linux/clk.h>
25#include <linux/delay.h>
26#include <linux/err.h>
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -070027#include <linux/interrupt.h>
28#include <linux/io.h>
29#include <linux/i2c.h>
30#include <linux/i2c/i2c-rcar.h>
31#include <linux/kernel.h>
32#include <linux/module.h>
Guennadi Liakhovetski7679c0e2013-09-12 14:36:46 +020033#include <linux/of_device.h>
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -070034#include <linux/platform_device.h>
35#include <linux/pm_runtime.h>
36#include <linux/slab.h>
Sergei Shtylyov91bfe292014-08-24 00:44:09 +040037#include <linux/spinlock.h>
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -070038
39/* register offsets */
40#define ICSCR 0x00 /* slave ctrl */
41#define ICMCR 0x04 /* master ctrl */
42#define ICSSR 0x08 /* slave status */
43#define ICMSR 0x0C /* master status */
44#define ICSIER 0x10 /* slave irq enable */
45#define ICMIER 0x14 /* master irq enable */
46#define ICCCR 0x18 /* clock dividers */
47#define ICSAR 0x1C /* slave address */
48#define ICMAR 0x20 /* master address */
49#define ICRXTX 0x24 /* data port */
50
Wolfram Sangde20d182014-11-18 17:04:55 +010051/* ICSCR */
52#define SDBS (1 << 3) /* slave data buffer select */
53#define SIE (1 << 2) /* slave interface enable */
54#define GCAE (1 << 1) /* general call address enable */
55#define FNA (1 << 0) /* forced non acknowledgment */
56
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -070057/* ICMCR */
58#define MDBS (1 << 7) /* non-fifo mode switch */
59#define FSCL (1 << 6) /* override SCL pin */
60#define FSDA (1 << 5) /* override SDA pin */
61#define OBPC (1 << 4) /* override pins */
62#define MIE (1 << 3) /* master if enable */
63#define TSBE (1 << 2)
64#define FSB (1 << 1) /* force stop bit */
65#define ESG (1 << 0) /* en startbit gen */
66
Wolfram Sangde20d182014-11-18 17:04:55 +010067/* ICSSR (also for ICSIER) */
68#define GCAR (1 << 6) /* general call received */
69#define STM (1 << 5) /* slave transmit mode */
70#define SSR (1 << 4) /* stop received */
71#define SDE (1 << 3) /* slave data empty */
72#define SDT (1 << 2) /* slave data transmitted */
73#define SDR (1 << 1) /* slave data received */
74#define SAR (1 << 0) /* slave addr received */
75
Wolfram Sang3e3aaba2014-05-28 09:44:44 +020076/* ICMSR (also for ICMIE) */
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -070077#define MNR (1 << 6) /* nack received */
78#define MAL (1 << 5) /* arbitration lost */
79#define MST (1 << 4) /* sent a stop */
80#define MDE (1 << 3)
81#define MDT (1 << 2)
82#define MDR (1 << 1)
83#define MAT (1 << 0) /* slave addr xfer done */
84
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -070085
Wolfram Sang4f443a82014-05-28 09:44:38 +020086#define RCAR_BUS_PHASE_START (MDBS | MIE | ESG)
87#define RCAR_BUS_PHASE_DATA (MDBS | MIE)
88#define RCAR_BUS_PHASE_STOP (MDBS | MIE | FSB)
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -070089
Wolfram Sang3e3aaba2014-05-28 09:44:44 +020090#define RCAR_IRQ_SEND (MNR | MAL | MST | MAT | MDE)
91#define RCAR_IRQ_RECV (MNR | MAL | MST | MAT | MDR)
92#define RCAR_IRQ_STOP (MST)
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -070093
Sergei Shtylyov938916f2014-09-06 03:34:32 +040094#define RCAR_IRQ_ACK_SEND (~(MAT | MDE) & 0xFF)
95#define RCAR_IRQ_ACK_RECV (~(MAT | MDR) & 0xFF)
Wolfram Sang3c95de62014-05-28 09:44:42 +020096
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -070097#define ID_LAST_MSG (1 << 0)
98#define ID_IOERROR (1 << 1)
99#define ID_DONE (1 << 2)
100#define ID_ARBLOST (1 << 3)
101#define ID_NACK (1 << 4)
102
Nguyen Viet Dungb7204232013-09-03 09:09:25 +0900103enum rcar_i2c_type {
Kuninori Morimoto043a3f12013-10-21 01:04:32 -0700104 I2C_RCAR_GEN1,
105 I2C_RCAR_GEN2,
Nguyen Viet Dungb7204232013-09-03 09:09:25 +0900106};
107
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700108struct rcar_i2c_priv {
109 void __iomem *io;
110 struct i2c_adapter adap;
111 struct i2c_msg *msg;
Ben Dooksbc8120f2014-01-26 16:05:35 +0000112 struct clk *clk;
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700113
Sergei Shtylyov91bfe292014-08-24 00:44:09 +0400114 spinlock_t lock;
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700115 wait_queue_head_t wait;
116
117 int pos;
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700118 u32 icccr;
119 u32 flags;
Wolfram Sang51371cd2014-05-28 09:44:45 +0200120 enum rcar_i2c_type devtype;
Wolfram Sangde20d182014-11-18 17:04:55 +0100121 struct i2c_client *slave;
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700122};
123
124#define rcar_i2c_priv_to_dev(p) ((p)->adap.dev.parent)
125#define rcar_i2c_is_recv(p) ((p)->msg->flags & I2C_M_RD)
126
127#define rcar_i2c_flags_set(p, f) ((p)->flags |= (f))
128#define rcar_i2c_flags_has(p, f) ((p)->flags & (f))
129
130#define LOOP_TIMEOUT 1024
131
Wolfram Sang51371cd2014-05-28 09:44:45 +0200132
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700133static void rcar_i2c_write(struct rcar_i2c_priv *priv, int reg, u32 val)
134{
135 writel(val, priv->io + reg);
136}
137
138static u32 rcar_i2c_read(struct rcar_i2c_priv *priv, int reg)
139{
140 return readl(priv->io + reg);
141}
142
143static void rcar_i2c_init(struct rcar_i2c_priv *priv)
144{
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700145 /* reset master mode */
146 rcar_i2c_write(priv, ICMIER, 0);
147 rcar_i2c_write(priv, ICMCR, 0);
148 rcar_i2c_write(priv, ICMSR, 0);
149 rcar_i2c_write(priv, ICMAR, 0);
150}
151
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700152static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv)
153{
154 int i;
155
156 for (i = 0; i < LOOP_TIMEOUT; i++) {
157 /* make sure that bus is not busy */
158 if (!(rcar_i2c_read(priv, ICMCR) & FSDA))
159 return 0;
160 udelay(1);
161 }
162
163 return -EBUSY;
164}
165
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700166static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv,
167 u32 bus_speed,
168 struct device *dev)
169{
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700170 u32 scgd, cdf;
171 u32 round, ick;
172 u32 scl;
Nguyen Viet Dungb7204232013-09-03 09:09:25 +0900173 u32 cdf_width;
Guennadi Liakhovetski8d049402013-09-12 14:36:45 +0200174 unsigned long rate;
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700175
Nguyen Viet Dungb7204232013-09-03 09:09:25 +0900176 switch (priv->devtype) {
Kuninori Morimoto043a3f12013-10-21 01:04:32 -0700177 case I2C_RCAR_GEN1:
Nguyen Viet Dungb7204232013-09-03 09:09:25 +0900178 cdf_width = 2;
179 break;
Kuninori Morimoto043a3f12013-10-21 01:04:32 -0700180 case I2C_RCAR_GEN2:
Nguyen Viet Dungb7204232013-09-03 09:09:25 +0900181 cdf_width = 3;
182 break;
183 default:
184 dev_err(dev, "device type error\n");
185 return -EIO;
186 }
187
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700188 /*
189 * calculate SCL clock
190 * see
191 * ICCCR
192 *
193 * ick = clkp / (1 + CDF)
194 * SCL = ick / (20 + SCGD * 8 + F[(ticf + tr + intd) * ick])
195 *
196 * ick : I2C internal clock < 20 MHz
197 * ticf : I2C SCL falling time = 35 ns here
198 * tr : I2C SCL rising time = 200 ns here
199 * intd : LSI internal delay = 50 ns here
200 * clkp : peripheral_clk
201 * F[] : integer up-valuation
202 */
Ben Dooksbc8120f2014-01-26 16:05:35 +0000203 rate = clk_get_rate(priv->clk);
Guennadi Liakhovetski8d049402013-09-12 14:36:45 +0200204 cdf = rate / 20000000;
Wolfram Sang22762cc2014-09-20 12:07:37 +0200205 if (cdf >= 1U << cdf_width) {
Guennadi Liakhovetski8d049402013-09-12 14:36:45 +0200206 dev_err(dev, "Input clock %lu too high\n", rate);
207 return -EIO;
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700208 }
Guennadi Liakhovetski8d049402013-09-12 14:36:45 +0200209 ick = rate / (cdf + 1);
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700210
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700211 /*
212 * it is impossible to calculate large scale
213 * number on u32. separate it
214 *
215 * F[(ticf + tr + intd) * ick]
216 * = F[(35 + 200 + 50)ns * ick]
217 * = F[285 * ick / 1000000000]
218 * = F[(ick / 1000000) * 285 / 1000]
219 */
220 round = (ick + 500000) / 1000000 * 285;
221 round = (round + 500) / 1000;
222
223 /*
224 * SCL = ick / (20 + SCGD * 8 + F[(ticf + tr + intd) * ick])
225 *
226 * Calculation result (= SCL) should be less than
227 * bus_speed for hardware safety
Guennadi Liakhovetski8d049402013-09-12 14:36:45 +0200228 *
229 * We could use something along the lines of
230 * div = ick / (bus_speed + 1) + 1;
231 * scgd = (div - 20 - round + 7) / 8;
232 * scl = ick / (20 + (scgd * 8) + round);
233 * (not fully verified) but that would get pretty involved
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700234 */
235 for (scgd = 0; scgd < 0x40; scgd++) {
236 scl = ick / (20 + (scgd * 8) + round);
237 if (scl <= bus_speed)
238 goto scgd_find;
239 }
240 dev_err(dev, "it is impossible to calculate best SCL\n");
241 return -EIO;
242
243scgd_find:
244 dev_dbg(dev, "clk %d/%d(%lu), round %u, CDF:0x%x, SCGD: 0x%x\n",
Ben Dooksbc8120f2014-01-26 16:05:35 +0000245 scl, bus_speed, clk_get_rate(priv->clk), round, cdf, scgd);
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700246
247 /*
248 * keep icccr value
249 */
Guennadi Liakhovetski14d32f12013-09-12 14:36:44 +0200250 priv->icccr = scgd << cdf_width | cdf;
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700251
252 return 0;
253}
254
Sergei Shtylyov7c7117f2014-09-15 00:15:46 +0400255static void rcar_i2c_prepare_msg(struct rcar_i2c_priv *priv)
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700256{
Wolfram Sang386babf2014-05-28 09:44:41 +0200257 int read = !!rcar_i2c_is_recv(priv);
258
259 rcar_i2c_write(priv, ICMAR, (priv->msg->addr << 1) | read);
Wolfram Sang3c95de62014-05-28 09:44:42 +0200260 rcar_i2c_write(priv, ICMSR, 0);
Wolfram Sang4f443a82014-05-28 09:44:38 +0200261 rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START);
Wolfram Sang386babf2014-05-28 09:44:41 +0200262 rcar_i2c_write(priv, ICMIER, read ? RCAR_IRQ_RECV : RCAR_IRQ_SEND);
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700263}
264
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700265/*
266 * interrupt functions
267 */
268static int rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr)
269{
270 struct i2c_msg *msg = priv->msg;
271
272 /*
273 * FIXME
274 * sometimes, unknown interrupt happened.
275 * Do nothing
276 */
277 if (!(msr & MDE))
278 return 0;
279
280 /*
281 * If address transfer phase finished,
282 * goto data phase.
283 */
284 if (msr & MAT)
Wolfram Sang4f443a82014-05-28 09:44:38 +0200285 rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA);
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700286
287 if (priv->pos < msg->len) {
288 /*
289 * Prepare next data to ICRXTX register.
290 * This data will go to _SHIFT_ register.
291 *
292 * *
293 * [ICRXTX] -> [SHIFT] -> [I2C bus]
294 */
295 rcar_i2c_write(priv, ICRXTX, msg->buf[priv->pos]);
296 priv->pos++;
297
298 } else {
299 /*
300 * The last data was pushed to ICRXTX on _PREV_ empty irq.
301 * It is on _SHIFT_ register, and will sent to I2C bus.
302 *
303 * *
304 * [ICRXTX] -> [SHIFT] -> [I2C bus]
305 */
306
307 if (priv->flags & ID_LAST_MSG)
308 /*
309 * If current msg is the _LAST_ msg,
310 * prepare stop condition here.
311 * ID_DONE will be set on STOP irq.
312 */
Wolfram Sang4f443a82014-05-28 09:44:38 +0200313 rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP);
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700314 else
315 /*
316 * If current msg is _NOT_ last msg,
317 * it doesn't call stop phase.
318 * thus, there is no STOP irq.
319 * return ID_DONE here.
320 */
321 return ID_DONE;
322 }
323
Wolfram Sang3c95de62014-05-28 09:44:42 +0200324 rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_SEND);
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700325
326 return 0;
327}
328
329static int rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr)
330{
331 struct i2c_msg *msg = priv->msg;
332
333 /*
334 * FIXME
335 * sometimes, unknown interrupt happened.
336 * Do nothing
337 */
338 if (!(msr & MDR))
339 return 0;
340
341 if (msr & MAT) {
342 /*
343 * Address transfer phase finished,
344 * but, there is no data at this point.
345 * Do nothing.
346 */
347 } else if (priv->pos < msg->len) {
348 /*
349 * get received data
350 */
351 msg->buf[priv->pos] = rcar_i2c_read(priv, ICRXTX);
352 priv->pos++;
353 }
354
355 /*
356 * If next received data is the _LAST_,
357 * go to STOP phase,
358 * otherwise, go to DATA phase.
359 */
360 if (priv->pos + 1 >= msg->len)
Wolfram Sang4f443a82014-05-28 09:44:38 +0200361 rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP);
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700362 else
Wolfram Sang4f443a82014-05-28 09:44:38 +0200363 rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA);
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700364
Wolfram Sang3c95de62014-05-28 09:44:42 +0200365 rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_RECV);
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700366
367 return 0;
368}
369
Wolfram Sangde20d182014-11-18 17:04:55 +0100370static bool rcar_i2c_slave_irq(struct rcar_i2c_priv *priv)
371{
372 u32 ssr_raw, ssr_filtered;
373 u8 value;
374
375 ssr_raw = rcar_i2c_read(priv, ICSSR) & 0xff;
376 ssr_filtered = ssr_raw & rcar_i2c_read(priv, ICSIER);
377
378 if (!ssr_filtered)
379 return false;
380
381 /* address detected */
382 if (ssr_filtered & SAR) {
383 /* read or write request */
384 if (ssr_raw & STM) {
Wolfram Sang5b77d162015-03-23 09:26:36 +0100385 i2c_slave_event(priv->slave, I2C_SLAVE_READ_REQUESTED, &value);
Wolfram Sangde20d182014-11-18 17:04:55 +0100386 rcar_i2c_write(priv, ICRXTX, value);
387 rcar_i2c_write(priv, ICSIER, SDE | SSR | SAR);
388 } else {
Wolfram Sang5b77d162015-03-23 09:26:36 +0100389 i2c_slave_event(priv->slave, I2C_SLAVE_WRITE_REQUESTED, &value);
Wolfram Sangde20d182014-11-18 17:04:55 +0100390 rcar_i2c_read(priv, ICRXTX); /* dummy read */
391 rcar_i2c_write(priv, ICSIER, SDR | SSR | SAR);
392 }
393
394 rcar_i2c_write(priv, ICSSR, ~SAR & 0xff);
395 }
396
397 /* master sent stop */
398 if (ssr_filtered & SSR) {
399 i2c_slave_event(priv->slave, I2C_SLAVE_STOP, &value);
400 rcar_i2c_write(priv, ICSIER, SAR | SSR);
401 rcar_i2c_write(priv, ICSSR, ~SSR & 0xff);
402 }
403
404 /* master wants to write to us */
405 if (ssr_filtered & SDR) {
406 int ret;
407
408 value = rcar_i2c_read(priv, ICRXTX);
Wolfram Sang5b77d162015-03-23 09:26:36 +0100409 ret = i2c_slave_event(priv->slave, I2C_SLAVE_WRITE_RECEIVED, &value);
Wolfram Sangde20d182014-11-18 17:04:55 +0100410 /* Send NACK in case of error */
411 rcar_i2c_write(priv, ICSCR, SIE | SDBS | (ret < 0 ? FNA : 0));
Wolfram Sangde20d182014-11-18 17:04:55 +0100412 rcar_i2c_write(priv, ICSSR, ~SDR & 0xff);
413 }
414
415 /* master wants to read from us */
416 if (ssr_filtered & SDE) {
Wolfram Sang5b77d162015-03-23 09:26:36 +0100417 i2c_slave_event(priv->slave, I2C_SLAVE_READ_PROCESSED, &value);
Wolfram Sangde20d182014-11-18 17:04:55 +0100418 rcar_i2c_write(priv, ICRXTX, value);
419 rcar_i2c_write(priv, ICSSR, ~SDE & 0xff);
420 }
421
422 return true;
423}
424
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700425static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
426{
427 struct rcar_i2c_priv *priv = ptr;
Sergei Shtylyovaa5beaf2014-09-15 00:20:19 +0400428 irqreturn_t result = IRQ_HANDLED;
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700429 u32 msr;
430
Sergei Shtylyov91bfe292014-08-24 00:44:09 +0400431 /*-------------- spin lock -----------------*/
432 spin_lock(&priv->lock);
433
Wolfram Sangde20d182014-11-18 17:04:55 +0100434 if (rcar_i2c_slave_irq(priv))
435 goto exit;
436
Wolfram Sang1c176d52014-05-28 09:44:36 +0200437 msr = rcar_i2c_read(priv, ICMSR);
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700438
Sergei Shtylyovdd318b02014-09-02 01:15:26 +0400439 /* Only handle interrupts that are currently enabled */
440 msr &= rcar_i2c_read(priv, ICMIER);
Sergei Shtylyovaa5beaf2014-09-15 00:20:19 +0400441 if (!msr) {
442 result = IRQ_NONE;
443 goto exit;
444 }
Sergei Shtylyovdd318b02014-09-02 01:15:26 +0400445
Wolfram Sang51371cd2014-05-28 09:44:45 +0200446 /* Arbitration lost */
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700447 if (msr & MAL) {
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700448 rcar_i2c_flags_set(priv, (ID_DONE | ID_ARBLOST));
449 goto out;
450 }
451
Wolfram Sang51371cd2014-05-28 09:44:45 +0200452 /* Nack */
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700453 if (msr & MNR) {
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700454 /* go to stop phase */
Wolfram Sang4f443a82014-05-28 09:44:38 +0200455 rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP);
Wolfram Sangf2382242014-05-28 09:44:39 +0200456 rcar_i2c_write(priv, ICMIER, RCAR_IRQ_STOP);
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700457 rcar_i2c_flags_set(priv, ID_NACK);
458 goto out;
459 }
460
Sergei Shtylyovdd318b02014-09-02 01:15:26 +0400461 /* Stop */
462 if (msr & MST) {
463 rcar_i2c_flags_set(priv, ID_DONE);
464 goto out;
465 }
466
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700467 if (rcar_i2c_is_recv(priv))
468 rcar_i2c_flags_set(priv, rcar_i2c_irq_recv(priv, msr));
469 else
470 rcar_i2c_flags_set(priv, rcar_i2c_irq_send(priv, msr));
471
472out:
473 if (rcar_i2c_flags_has(priv, ID_DONE)) {
Wolfram Sangf2382242014-05-28 09:44:39 +0200474 rcar_i2c_write(priv, ICMIER, 0);
Wolfram Sang3c95de62014-05-28 09:44:42 +0200475 rcar_i2c_write(priv, ICMSR, 0);
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700476 wake_up(&priv->wait);
477 }
478
Sergei Shtylyovaa5beaf2014-09-15 00:20:19 +0400479exit:
Sergei Shtylyov91bfe292014-08-24 00:44:09 +0400480 spin_unlock(&priv->lock);
481 /*-------------- spin unlock -----------------*/
482
Sergei Shtylyovaa5beaf2014-09-15 00:20:19 +0400483 return result;
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700484}
485
486static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
487 struct i2c_msg *msgs,
488 int num)
489{
490 struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
491 struct device *dev = rcar_i2c_priv_to_dev(priv);
Sergei Shtylyov91bfe292014-08-24 00:44:09 +0400492 unsigned long flags;
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700493 int i, ret, timeout;
494
495 pm_runtime_get_sync(dev);
496
Sergei Shtylyov91bfe292014-08-24 00:44:09 +0400497 /*-------------- spin lock -----------------*/
498 spin_lock_irqsave(&priv->lock, flags);
499
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700500 rcar_i2c_init(priv);
Wolfram Sang1c176d52014-05-28 09:44:36 +0200501 /* start clock */
502 rcar_i2c_write(priv, ICCCR, priv->icccr);
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700503
Sergei Shtylyov91bfe292014-08-24 00:44:09 +0400504 spin_unlock_irqrestore(&priv->lock, flags);
505 /*-------------- spin unlock -----------------*/
506
Wolfram Sang3f7de222014-05-28 09:44:40 +0200507 ret = rcar_i2c_bus_barrier(priv);
508 if (ret < 0)
509 goto out;
510
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700511 for (i = 0; i < num; i++) {
Wolfram Sangd7653962014-05-05 18:36:21 +0200512 /* This HW can't send STOP after address phase */
513 if (msgs[i].len == 0) {
514 ret = -EOPNOTSUPP;
515 break;
516 }
517
Sergei Shtylyov91bfe292014-08-24 00:44:09 +0400518 /*-------------- spin lock -----------------*/
519 spin_lock_irqsave(&priv->lock, flags);
520
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700521 /* init each data */
522 priv->msg = &msgs[i];
523 priv->pos = 0;
524 priv->flags = 0;
Sergei Shtylyovc30d7662014-09-15 00:14:14 +0400525 if (i == num - 1)
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700526 rcar_i2c_flags_set(priv, ID_LAST_MSG);
527
Sergei Shtylyov7c7117f2014-09-15 00:15:46 +0400528 rcar_i2c_prepare_msg(priv);
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700529
Sergei Shtylyov91bfe292014-08-24 00:44:09 +0400530 spin_unlock_irqrestore(&priv->lock, flags);
531 /*-------------- spin unlock -----------------*/
532
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700533 timeout = wait_event_timeout(priv->wait,
534 rcar_i2c_flags_has(priv, ID_DONE),
535 5 * HZ);
536 if (!timeout) {
537 ret = -ETIMEDOUT;
538 break;
539 }
540
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700541 if (rcar_i2c_flags_has(priv, ID_NACK)) {
Ben Dooks6ff4b1052014-01-26 16:05:37 +0000542 ret = -ENXIO;
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700543 break;
544 }
545
546 if (rcar_i2c_flags_has(priv, ID_ARBLOST)) {
547 ret = -EAGAIN;
548 break;
549 }
550
551 if (rcar_i2c_flags_has(priv, ID_IOERROR)) {
552 ret = -EIO;
553 break;
554 }
555
556 ret = i + 1; /* The number of transfer */
557 }
Wolfram Sang3f7de222014-05-28 09:44:40 +0200558out:
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700559 pm_runtime_put(dev);
560
Ben Dooks6ff4b1052014-01-26 16:05:37 +0000561 if (ret < 0 && ret != -ENXIO)
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700562 dev_err(dev, "error %d : %x\n", ret, priv->flags);
563
564 return ret;
565}
566
Wolfram Sangde20d182014-11-18 17:04:55 +0100567static int rcar_reg_slave(struct i2c_client *slave)
568{
569 struct rcar_i2c_priv *priv = i2c_get_adapdata(slave->adapter);
570
571 if (priv->slave)
572 return -EBUSY;
573
574 if (slave->flags & I2C_CLIENT_TEN)
575 return -EAFNOSUPPORT;
576
577 pm_runtime_forbid(rcar_i2c_priv_to_dev(priv));
578
579 priv->slave = slave;
580 rcar_i2c_write(priv, ICSAR, slave->addr);
581 rcar_i2c_write(priv, ICSSR, 0);
582 rcar_i2c_write(priv, ICSIER, SAR | SSR);
583 rcar_i2c_write(priv, ICSCR, SIE | SDBS);
584
585 return 0;
586}
587
588static int rcar_unreg_slave(struct i2c_client *slave)
589{
590 struct rcar_i2c_priv *priv = i2c_get_adapdata(slave->adapter);
591
592 WARN_ON(!priv->slave);
593
594 rcar_i2c_write(priv, ICSIER, 0);
595 rcar_i2c_write(priv, ICSCR, 0);
596
597 priv->slave = NULL;
598
599 pm_runtime_allow(rcar_i2c_priv_to_dev(priv));
600
601 return 0;
602}
603
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700604static u32 rcar_i2c_func(struct i2c_adapter *adap)
605{
Wolfram Sangd7653962014-05-05 18:36:21 +0200606 /* This HW can't do SMBUS_QUICK and NOSTART */
607 return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700608}
609
610static const struct i2c_algorithm rcar_i2c_algo = {
611 .master_xfer = rcar_i2c_master_xfer,
612 .functionality = rcar_i2c_func,
Wolfram Sangde20d182014-11-18 17:04:55 +0100613 .reg_slave = rcar_reg_slave,
614 .unreg_slave = rcar_unreg_slave,
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700615};
616
Guennadi Liakhovetski7679c0e2013-09-12 14:36:46 +0200617static const struct of_device_id rcar_i2c_dt_ids[] = {
Kuninori Morimoto043a3f12013-10-21 01:04:32 -0700618 { .compatible = "renesas,i2c-rcar", .data = (void *)I2C_RCAR_GEN1 },
619 { .compatible = "renesas,i2c-r8a7778", .data = (void *)I2C_RCAR_GEN1 },
620 { .compatible = "renesas,i2c-r8a7779", .data = (void *)I2C_RCAR_GEN1 },
621 { .compatible = "renesas,i2c-r8a7790", .data = (void *)I2C_RCAR_GEN2 },
Wolfram Sange8936452014-02-20 09:03:20 +0100622 { .compatible = "renesas,i2c-r8a7791", .data = (void *)I2C_RCAR_GEN2 },
Wolfram Sang819a3952014-05-27 14:06:28 +0200623 { .compatible = "renesas,i2c-r8a7792", .data = (void *)I2C_RCAR_GEN2 },
624 { .compatible = "renesas,i2c-r8a7793", .data = (void *)I2C_RCAR_GEN2 },
625 { .compatible = "renesas,i2c-r8a7794", .data = (void *)I2C_RCAR_GEN2 },
Guennadi Liakhovetski7679c0e2013-09-12 14:36:46 +0200626 {},
627};
628MODULE_DEVICE_TABLE(of, rcar_i2c_dt_ids);
629
Bill Pemberton0b255e92012-11-27 15:59:38 -0500630static int rcar_i2c_probe(struct platform_device *pdev)
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700631{
Jingoo Han6d4028c2013-07-30 16:59:33 +0900632 struct i2c_rcar_platform_data *pdata = dev_get_platdata(&pdev->dev);
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700633 struct rcar_i2c_priv *priv;
634 struct i2c_adapter *adap;
635 struct resource *res;
636 struct device *dev = &pdev->dev;
637 u32 bus_speed;
Wolfram Sang93e953d2014-05-28 09:44:37 +0200638 int irq, ret;
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700639
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700640 priv = devm_kzalloc(dev, sizeof(struct rcar_i2c_priv), GFP_KERNEL);
Jingoo Han46797a22014-05-13 10:51:58 +0900641 if (!priv)
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700642 return -ENOMEM;
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700643
Ben Dooksbc8120f2014-01-26 16:05:35 +0000644 priv->clk = devm_clk_get(dev, NULL);
645 if (IS_ERR(priv->clk)) {
646 dev_err(dev, "cannot get clock\n");
647 return PTR_ERR(priv->clk);
648 }
649
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700650 bus_speed = 100000; /* default 100 kHz */
Guennadi Liakhovetski7679c0e2013-09-12 14:36:46 +0200651 ret = of_property_read_u32(dev->of_node, "clock-frequency", &bus_speed);
652 if (ret < 0 && pdata && pdata->bus_speed)
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700653 bus_speed = pdata->bus_speed;
Nguyen Viet Dungb7204232013-09-03 09:09:25 +0900654
Guennadi Liakhovetski7679c0e2013-09-12 14:36:46 +0200655 if (pdev->dev.of_node)
656 priv->devtype = (long)of_match_device(rcar_i2c_dt_ids,
657 dev)->data;
658 else
659 priv->devtype = platform_get_device_id(pdev)->driver_data;
Nguyen Viet Dungb7204232013-09-03 09:09:25 +0900660
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700661 ret = rcar_i2c_clock_calculate(priv, bus_speed, dev);
662 if (ret < 0)
663 return ret;
664
Wolfram Sang3cc2d002013-05-10 10:16:54 +0200665 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
Thierry Reding84dbf802013-01-21 11:09:03 +0100666 priv->io = devm_ioremap_resource(dev, res);
667 if (IS_ERR(priv->io))
668 return PTR_ERR(priv->io);
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700669
Wolfram Sang93e953d2014-05-28 09:44:37 +0200670 irq = platform_get_irq(pdev, 0);
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700671 init_waitqueue_head(&priv->wait);
Sergei Shtylyov91bfe292014-08-24 00:44:09 +0400672 spin_lock_init(&priv->lock);
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700673
Wolfram Sang929e3aba2014-07-10 13:46:31 +0200674 adap = &priv->adap;
675 adap->nr = pdev->id;
676 adap->algo = &rcar_i2c_algo;
677 adap->class = I2C_CLASS_DEPRECATED;
678 adap->retries = 3;
679 adap->dev.parent = dev;
680 adap->dev.of_node = dev->of_node;
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700681 i2c_set_adapdata(adap, priv);
682 strlcpy(adap->name, pdev->name, sizeof(adap->name));
683
Wolfram Sang93e953d2014-05-28 09:44:37 +0200684 ret = devm_request_irq(dev, irq, rcar_i2c_irq, 0,
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700685 dev_name(dev), priv);
686 if (ret < 0) {
Wolfram Sang93e953d2014-05-28 09:44:37 +0200687 dev_err(dev, "cannot get irq %d\n", irq);
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700688 return ret;
689 }
690
691 ret = i2c_add_numbered_adapter(adap);
692 if (ret < 0) {
693 dev_err(dev, "reg adap failed: %d\n", ret);
694 return ret;
695 }
696
697 pm_runtime_enable(dev);
698 platform_set_drvdata(pdev, priv);
699
700 dev_info(dev, "probed\n");
701
702 return 0;
703}
704
Bill Pemberton0b255e92012-11-27 15:59:38 -0500705static int rcar_i2c_remove(struct platform_device *pdev)
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700706{
707 struct rcar_i2c_priv *priv = platform_get_drvdata(pdev);
708 struct device *dev = &pdev->dev;
709
710 i2c_del_adapter(&priv->adap);
711 pm_runtime_disable(dev);
712
713 return 0;
714}
715
Nguyen Viet Dungb7204232013-09-03 09:09:25 +0900716static struct platform_device_id rcar_i2c_id_table[] = {
Kuninori Morimoto043a3f12013-10-21 01:04:32 -0700717 { "i2c-rcar", I2C_RCAR_GEN1 },
718 { "i2c-rcar_gen1", I2C_RCAR_GEN1 },
719 { "i2c-rcar_gen2", I2C_RCAR_GEN2 },
Nguyen Viet Dungb7204232013-09-03 09:09:25 +0900720 {},
721};
722MODULE_DEVICE_TABLE(platform, rcar_i2c_id_table);
723
Wolfram Sang45fd5e42012-11-13 11:24:15 +0100724static struct platform_driver rcar_i2c_driver = {
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700725 .driver = {
726 .name = "i2c-rcar",
Guennadi Liakhovetski7679c0e2013-09-12 14:36:46 +0200727 .of_match_table = rcar_i2c_dt_ids,
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700728 },
729 .probe = rcar_i2c_probe,
Bill Pemberton0b255e92012-11-27 15:59:38 -0500730 .remove = rcar_i2c_remove,
Nguyen Viet Dungb7204232013-09-03 09:09:25 +0900731 .id_table = rcar_i2c_id_table,
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700732};
733
Wolfram Sang45fd5e42012-11-13 11:24:15 +0100734module_platform_driver(rcar_i2c_driver);
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700735
Wolfram Sang3d99bea2014-05-28 09:44:46 +0200736MODULE_LICENSE("GPL v2");
Kuninori Morimoto6ccbe602012-09-27 23:44:25 -0700737MODULE_DESCRIPTION("Renesas R-Car I2C bus driver");
738MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");