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Vladimir Barinov95a7f102007-10-13 23:56:30 +02001/*
2 * TI DAVINCI I2C adapter driver.
3 *
4 * Copyright (C) 2006 Texas Instruments.
5 * Copyright (C) 2007 MontaVista Software Inc.
6 *
7 * Updated by Vinod & Sudhakar Feb 2005
8 *
9 * ----------------------------------------------------------------------------
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 * ----------------------------------------------------------------------------
25 *
26 */
27#include <linux/kernel.h>
28#include <linux/module.h>
29#include <linux/delay.h>
30#include <linux/i2c.h>
31#include <linux/clk.h>
32#include <linux/errno.h>
33#include <linux/sched.h>
34#include <linux/err.h>
35#include <linux/interrupt.h>
36#include <linux/platform_device.h>
37#include <linux/io.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090038#include <linux/slab.h>
Vladimir Barinov95a7f102007-10-13 23:56:30 +020039
Russell Kinga09e64f2008-08-05 16:14:15 +010040#include <mach/hardware.h>
Russell Kinga09e64f2008-08-05 16:14:15 +010041#include <mach/i2c.h>
Vladimir Barinov95a7f102007-10-13 23:56:30 +020042
43/* ----- global defines ----------------------------------------------- */
44
45#define DAVINCI_I2C_TIMEOUT (1*HZ)
46#define I2C_DAVINCI_INTR_ALL (DAVINCI_I2C_IMR_AAS | \
47 DAVINCI_I2C_IMR_SCD | \
48 DAVINCI_I2C_IMR_ARDY | \
49 DAVINCI_I2C_IMR_NACK | \
50 DAVINCI_I2C_IMR_AL)
51
52#define DAVINCI_I2C_OAR_REG 0x00
53#define DAVINCI_I2C_IMR_REG 0x04
54#define DAVINCI_I2C_STR_REG 0x08
55#define DAVINCI_I2C_CLKL_REG 0x0c
56#define DAVINCI_I2C_CLKH_REG 0x10
57#define DAVINCI_I2C_CNT_REG 0x14
58#define DAVINCI_I2C_DRR_REG 0x18
59#define DAVINCI_I2C_SAR_REG 0x1c
60#define DAVINCI_I2C_DXR_REG 0x20
61#define DAVINCI_I2C_MDR_REG 0x24
62#define DAVINCI_I2C_IVR_REG 0x28
63#define DAVINCI_I2C_EMDR_REG 0x2c
64#define DAVINCI_I2C_PSC_REG 0x30
65
66#define DAVINCI_I2C_IVR_AAS 0x07
67#define DAVINCI_I2C_IVR_SCD 0x06
68#define DAVINCI_I2C_IVR_XRDY 0x05
69#define DAVINCI_I2C_IVR_RDR 0x04
70#define DAVINCI_I2C_IVR_ARDY 0x03
71#define DAVINCI_I2C_IVR_NACK 0x02
72#define DAVINCI_I2C_IVR_AL 0x01
73
Chaithrika U Sc062a252010-01-06 14:54:57 +053074#define DAVINCI_I2C_STR_BB BIT(12)
75#define DAVINCI_I2C_STR_RSFULL BIT(11)
76#define DAVINCI_I2C_STR_SCD BIT(5)
77#define DAVINCI_I2C_STR_ARDY BIT(2)
78#define DAVINCI_I2C_STR_NACK BIT(1)
79#define DAVINCI_I2C_STR_AL BIT(0)
Vladimir Barinov95a7f102007-10-13 23:56:30 +020080
Chaithrika U Sc062a252010-01-06 14:54:57 +053081#define DAVINCI_I2C_MDR_NACK BIT(15)
82#define DAVINCI_I2C_MDR_STT BIT(13)
83#define DAVINCI_I2C_MDR_STP BIT(11)
84#define DAVINCI_I2C_MDR_MST BIT(10)
85#define DAVINCI_I2C_MDR_TRX BIT(9)
86#define DAVINCI_I2C_MDR_XA BIT(8)
87#define DAVINCI_I2C_MDR_RM BIT(7)
88#define DAVINCI_I2C_MDR_IRS BIT(5)
Vladimir Barinov95a7f102007-10-13 23:56:30 +020089
Chaithrika U Sc062a252010-01-06 14:54:57 +053090#define DAVINCI_I2C_IMR_AAS BIT(6)
91#define DAVINCI_I2C_IMR_SCD BIT(5)
92#define DAVINCI_I2C_IMR_XRDY BIT(4)
93#define DAVINCI_I2C_IMR_RRDY BIT(3)
94#define DAVINCI_I2C_IMR_ARDY BIT(2)
95#define DAVINCI_I2C_IMR_NACK BIT(1)
96#define DAVINCI_I2C_IMR_AL BIT(0)
Vladimir Barinov95a7f102007-10-13 23:56:30 +020097
98struct davinci_i2c_dev {
99 struct device *dev;
100 void __iomem *base;
101 struct completion cmd_complete;
102 struct clk *clk;
103 int cmd_err;
104 u8 *buf;
105 size_t buf_len;
106 int irq;
Dirk Behmec6c7c722008-03-28 06:16:12 +0100107 int stop;
Troy Kisky5a0d5f52008-07-14 22:38:21 +0200108 u8 terminate;
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200109 struct i2c_adapter adapter;
110};
111
112/* default platform data to use if not supplied in the platform_device */
113static struct davinci_i2c_platform_data davinci_i2c_platform_data_default = {
114 .bus_freq = 100,
115 .bus_delay = 0,
116};
117
118static inline void davinci_i2c_write_reg(struct davinci_i2c_dev *i2c_dev,
119 int reg, u16 val)
120{
121 __raw_writew(val, i2c_dev->base + reg);
122}
123
124static inline u16 davinci_i2c_read_reg(struct davinci_i2c_dev *i2c_dev, int reg)
125{
126 return __raw_readw(i2c_dev->base + reg);
127}
128
Chaithrika U S5ae5b112010-01-06 14:54:58 +0530129static inline void davinci_i2c_reset_ctrl(struct davinci_i2c_dev *i2c_dev,
130 int val)
131{
132 u16 w;
133
134 w = davinci_i2c_read_reg(i2c_dev, DAVINCI_I2C_MDR_REG);
135 if (!val) /* put I2C into reset */
136 w &= ~DAVINCI_I2C_MDR_IRS;
137 else /* take I2C out of reset */
138 w |= DAVINCI_I2C_MDR_IRS;
139
140 davinci_i2c_write_reg(i2c_dev, DAVINCI_I2C_MDR_REG, w);
141}
142
143static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev)
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200144{
145 struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
146 u16 psc;
147 u32 clk;
Troy Kiskycc99ff72008-07-14 22:38:20 +0200148 u32 d;
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200149 u32 clkh;
150 u32 clkl;
151 u32 input_clock = clk_get_rate(dev->clk);
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200152
153 /* NOTE: I2C Clock divider programming info
154 * As per I2C specs the following formulas provide prescaler
155 * and low/high divider values
156 * input clk --> PSC Div -----------> ICCL/H Div --> output clock
157 * module clk
158 *
159 * output clk = module clk / (PSC + 1) [ (ICCL + d) + (ICCH + d) ]
160 *
161 * Thus,
162 * (ICCL + ICCH) = clk = (input clk / ((psc +1) * output clk)) - 2d;
163 *
164 * where if PSC == 0, d = 7,
165 * if PSC == 1, d = 6
166 * if PSC > 1 , d = 5
167 */
168
Troy Kiskycc99ff72008-07-14 22:38:20 +0200169 /* get minimum of 7 MHz clock, but max of 12 MHz */
170 psc = (input_clock / 7000000) - 1;
171 if ((input_clock / (psc + 1)) > 12000000)
172 psc++; /* better to run under spec than over */
173 d = (psc >= 2) ? 5 : 7 - psc;
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200174
Troy Kiskycc99ff72008-07-14 22:38:20 +0200175 clk = ((input_clock / (psc + 1)) / (pdata->bus_freq * 1000)) - (d << 1);
176 clkh = clk >> 1;
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200177 clkl = clk - clkh;
178
179 davinci_i2c_write_reg(dev, DAVINCI_I2C_PSC_REG, psc);
180 davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKH_REG, clkh);
181 davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKL_REG, clkl);
182
Chaithrika U S5ae5b112010-01-06 14:54:58 +0530183 dev_dbg(dev->dev, "input_clock = %d, CLK = %d\n", input_clock, clk);
184}
185
186/*
187 * This function configures I2C and brings I2C out of reset.
188 * This function is called during I2C init function. This function
189 * also gets called if I2C encounters any errors.
190 */
191static int i2c_davinci_init(struct davinci_i2c_dev *dev)
192{
193 struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
194
195 if (!pdata)
196 pdata = &davinci_i2c_platform_data_default;
197
198 /* put I2C into reset */
199 davinci_i2c_reset_ctrl(dev, 0);
200
201 /* compute clock dividers */
202 i2c_davinci_calc_clk_dividers(dev);
203
David Brownell7605fa32009-07-06 15:48:36 -0700204 /* Respond at reserved "SMBus Host" slave address" (and zero);
205 * we seem to have no option to not respond...
206 */
207 davinci_i2c_write_reg(dev, DAVINCI_I2C_OAR_REG, 0x08);
208
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200209 dev_dbg(dev->dev, "PSC = %d\n",
210 davinci_i2c_read_reg(dev, DAVINCI_I2C_PSC_REG));
211 dev_dbg(dev->dev, "CLKL = %d\n",
212 davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKL_REG));
213 dev_dbg(dev->dev, "CLKH = %d\n",
214 davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKH_REG));
Troy Kiskycc99ff72008-07-14 22:38:20 +0200215 dev_dbg(dev->dev, "bus_freq = %dkHz, bus_delay = %d\n",
216 pdata->bus_freq, pdata->bus_delay);
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200217
218 /* Take the I2C module out of reset: */
Chaithrika U S5ae5b112010-01-06 14:54:58 +0530219 davinci_i2c_reset_ctrl(dev, 1);
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200220
221 /* Enable interrupts */
222 davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, I2C_DAVINCI_INTR_ALL);
223
224 return 0;
225}
226
227/*
228 * Waiting for bus not busy
229 */
230static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev,
231 char allow_sleep)
232{
233 unsigned long timeout;
234
Jean Delvare98a679c2009-03-28 21:34:43 +0100235 timeout = jiffies + dev->adapter.timeout;
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200236 while (davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG)
237 & DAVINCI_I2C_STR_BB) {
238 if (time_after(jiffies, timeout)) {
239 dev_warn(dev->dev,
240 "timeout waiting for bus ready\n");
241 return -ETIMEDOUT;
242 }
243 if (allow_sleep)
244 schedule_timeout(1);
245 }
246
247 return 0;
248}
249
250/*
251 * Low level master read/write transaction. This function is called
252 * from i2c_davinci_xfer.
253 */
254static int
255i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
256{
257 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
258 struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
259 u32 flag;
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200260 u16 w;
261 int r;
262
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200263 if (!pdata)
264 pdata = &davinci_i2c_platform_data_default;
265 /* Introduce a delay, required for some boards (e.g Davinci EVM) */
266 if (pdata->bus_delay)
267 udelay(pdata->bus_delay);
268
269 /* set the slave address */
270 davinci_i2c_write_reg(dev, DAVINCI_I2C_SAR_REG, msg->addr);
271
272 dev->buf = msg->buf;
273 dev->buf_len = msg->len;
Dirk Behmec6c7c722008-03-28 06:16:12 +0100274 dev->stop = stop;
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200275
276 davinci_i2c_write_reg(dev, DAVINCI_I2C_CNT_REG, dev->buf_len);
277
Troy Kisky2e743782008-07-14 22:38:21 +0200278 INIT_COMPLETION(dev->cmd_complete);
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200279 dev->cmd_err = 0;
280
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200281 /* Take I2C out of reset, configure it as master and set the
282 * start bit */
283 flag = DAVINCI_I2C_MDR_IRS | DAVINCI_I2C_MDR_MST | DAVINCI_I2C_MDR_STT;
284
285 /* if the slave address is ten bit address, enable XA bit */
286 if (msg->flags & I2C_M_TEN)
287 flag |= DAVINCI_I2C_MDR_XA;
288 if (!(msg->flags & I2C_M_RD))
289 flag |= DAVINCI_I2C_MDR_TRX;
290 if (stop)
291 flag |= DAVINCI_I2C_MDR_STP;
Dirk Behmec6c7c722008-03-28 06:16:12 +0100292 if (msg->len == 0) {
293 flag |= DAVINCI_I2C_MDR_RM;
294 flag &= ~DAVINCI_I2C_MDR_STP;
295 }
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200296
297 /* Enable receive or transmit interrupts */
298 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_IMR_REG);
299 if (msg->flags & I2C_M_RD)
Chaithrika U Sc062a252010-01-06 14:54:57 +0530300 w |= DAVINCI_I2C_IMR_RRDY;
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200301 else
Chaithrika U Sc062a252010-01-06 14:54:57 +0530302 w |= DAVINCI_I2C_IMR_XRDY;
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200303 davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, w);
304
Troy Kisky5a0d5f52008-07-14 22:38:21 +0200305 dev->terminate = 0;
Dirk Behmec6c7c722008-03-28 06:16:12 +0100306
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200307 /* write the data into mode register */
308 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
309
Dirk Behmec6c7c722008-03-28 06:16:12 +0100310 /*
311 * First byte should be set here, not after interrupt,
312 * because transmit-data-ready interrupt can come before
313 * NACK-interrupt during sending of previous message and
314 * ICDXR may have wrong data
315 */
316 if ((!(msg->flags & I2C_M_RD)) && dev->buf_len) {
317 davinci_i2c_write_reg(dev, DAVINCI_I2C_DXR_REG, *dev->buf++);
318 dev->buf_len--;
319 }
320
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200321 r = wait_for_completion_interruptible_timeout(&dev->cmd_complete,
Jean Delvare98a679c2009-03-28 21:34:43 +0100322 dev->adapter.timeout);
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200323 if (r == 0) {
324 dev_err(dev->dev, "controller timed out\n");
325 i2c_davinci_init(dev);
Troy Kisky5a0d5f52008-07-14 22:38:21 +0200326 dev->buf_len = 0;
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200327 return -ETIMEDOUT;
328 }
Troy Kisky5a0d5f52008-07-14 22:38:21 +0200329 if (dev->buf_len) {
330 /* This should be 0 if all bytes were transferred
331 * or dev->cmd_err denotes an error.
332 * A signal may have aborted the transfer.
333 */
334 if (r >= 0) {
335 dev_err(dev->dev, "abnormal termination buf_len=%i\n",
336 dev->buf_len);
337 r = -EREMOTEIO;
338 }
339 dev->terminate = 1;
340 wmb();
341 dev->buf_len = 0;
342 }
343 if (r < 0)
344 return r;
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200345
346 /* no error */
347 if (likely(!dev->cmd_err))
348 return msg->len;
349
350 /* We have an error */
351 if (dev->cmd_err & DAVINCI_I2C_STR_AL) {
352 i2c_davinci_init(dev);
353 return -EIO;
354 }
355
356 if (dev->cmd_err & DAVINCI_I2C_STR_NACK) {
357 if (msg->flags & I2C_M_IGNORE_NAK)
358 return msg->len;
359 if (stop) {
360 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
Chaithrika U Sc062a252010-01-06 14:54:57 +0530361 w |= DAVINCI_I2C_MDR_STP;
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200362 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
363 }
364 return -EREMOTEIO;
365 }
366 return -EIO;
367}
368
369/*
370 * Prepare controller for a transaction and call i2c_davinci_xfer_msg
371 */
372static int
373i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
374{
375 struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
376 int i;
377 int ret;
378
Harvey Harrison08882d22008-04-22 22:16:47 +0200379 dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200380
381 ret = i2c_davinci_wait_bus_not_busy(dev, 1);
382 if (ret < 0) {
383 dev_warn(dev->dev, "timeout waiting for bus ready\n");
384 return ret;
385 }
386
387 for (i = 0; i < num; i++) {
388 ret = i2c_davinci_xfer_msg(adap, &msgs[i], (i == (num - 1)));
Troy Kiskyd868caa2008-07-14 22:38:20 +0200389 dev_dbg(dev->dev, "%s [%d/%d] ret: %d\n", __func__, i + 1, num,
390 ret);
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200391 if (ret < 0)
392 return ret;
393 }
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200394 return num;
395}
396
397static u32 i2c_davinci_func(struct i2c_adapter *adap)
398{
Dirk Behmec6c7c722008-03-28 06:16:12 +0100399 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200400}
401
Troy Kisky5a0d5f52008-07-14 22:38:21 +0200402static void terminate_read(struct davinci_i2c_dev *dev)
403{
404 u16 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
405 w |= DAVINCI_I2C_MDR_NACK;
406 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
407
408 /* Throw away data */
409 davinci_i2c_read_reg(dev, DAVINCI_I2C_DRR_REG);
410 if (!dev->terminate)
411 dev_err(dev->dev, "RDR IRQ while no data requested\n");
412}
413static void terminate_write(struct davinci_i2c_dev *dev)
414{
415 u16 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
416 w |= DAVINCI_I2C_MDR_RM | DAVINCI_I2C_MDR_STP;
417 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
418
419 if (!dev->terminate)
David Brownell7605fa32009-07-06 15:48:36 -0700420 dev_dbg(dev->dev, "TDR IRQ while no data to send\n");
Troy Kisky5a0d5f52008-07-14 22:38:21 +0200421}
422
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200423/*
424 * Interrupt service routine. This gets called whenever an I2C interrupt
425 * occurs.
426 */
427static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
428{
429 struct davinci_i2c_dev *dev = dev_id;
430 u32 stat;
431 int count = 0;
432 u16 w;
433
434 while ((stat = davinci_i2c_read_reg(dev, DAVINCI_I2C_IVR_REG))) {
Harvey Harrison08882d22008-04-22 22:16:47 +0200435 dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200436 if (count++ == 100) {
437 dev_warn(dev->dev, "Too much work in one IRQ\n");
438 break;
439 }
440
441 switch (stat) {
442 case DAVINCI_I2C_IVR_AL:
Troy Kisky5a0d5f52008-07-14 22:38:21 +0200443 /* Arbitration lost, must retry */
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200444 dev->cmd_err |= DAVINCI_I2C_STR_AL;
Troy Kisky5a0d5f52008-07-14 22:38:21 +0200445 dev->buf_len = 0;
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200446 complete(&dev->cmd_complete);
447 break;
448
449 case DAVINCI_I2C_IVR_NACK:
450 dev->cmd_err |= DAVINCI_I2C_STR_NACK;
Troy Kisky5a0d5f52008-07-14 22:38:21 +0200451 dev->buf_len = 0;
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200452 complete(&dev->cmd_complete);
453 break;
454
455 case DAVINCI_I2C_IVR_ARDY:
Troy Kiskyb73a9ae2008-04-11 12:07:05 +0200456 davinci_i2c_write_reg(dev,
457 DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_ARDY);
Dirk Behmec6c7c722008-03-28 06:16:12 +0100458 if (((dev->buf_len == 0) && (dev->stop != 0)) ||
459 (dev->cmd_err & DAVINCI_I2C_STR_NACK)) {
460 w = davinci_i2c_read_reg(dev,
461 DAVINCI_I2C_MDR_REG);
462 w |= DAVINCI_I2C_MDR_STP;
463 davinci_i2c_write_reg(dev,
464 DAVINCI_I2C_MDR_REG, w);
465 }
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200466 complete(&dev->cmd_complete);
467 break;
468
469 case DAVINCI_I2C_IVR_RDR:
470 if (dev->buf_len) {
471 *dev->buf++ =
472 davinci_i2c_read_reg(dev,
473 DAVINCI_I2C_DRR_REG);
474 dev->buf_len--;
475 if (dev->buf_len)
476 continue;
477
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200478 davinci_i2c_write_reg(dev,
Troy Kiskyb73a9ae2008-04-11 12:07:05 +0200479 DAVINCI_I2C_STR_REG,
480 DAVINCI_I2C_IMR_RRDY);
Troy Kisky5a0d5f52008-07-14 22:38:21 +0200481 } else {
482 /* signal can terminate transfer */
483 terminate_read(dev);
484 }
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200485 break;
486
487 case DAVINCI_I2C_IVR_XRDY:
488 if (dev->buf_len) {
489 davinci_i2c_write_reg(dev, DAVINCI_I2C_DXR_REG,
490 *dev->buf++);
491 dev->buf_len--;
492 if (dev->buf_len)
493 continue;
494
495 w = davinci_i2c_read_reg(dev,
496 DAVINCI_I2C_IMR_REG);
Chaithrika U Sc062a252010-01-06 14:54:57 +0530497 w &= ~DAVINCI_I2C_IMR_XRDY;
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200498 davinci_i2c_write_reg(dev,
499 DAVINCI_I2C_IMR_REG,
500 w);
Troy Kisky5a0d5f52008-07-14 22:38:21 +0200501 } else {
502 /* signal can terminate transfer */
503 terminate_write(dev);
504 }
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200505 break;
506
507 case DAVINCI_I2C_IVR_SCD:
Troy Kiskyb73a9ae2008-04-11 12:07:05 +0200508 davinci_i2c_write_reg(dev,
509 DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_SCD);
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200510 complete(&dev->cmd_complete);
511 break;
512
513 case DAVINCI_I2C_IVR_AAS:
David Brownell7605fa32009-07-06 15:48:36 -0700514 dev_dbg(dev->dev, "Address as slave interrupt\n");
515 break;
516
517 default:
518 dev_warn(dev->dev, "Unrecognized irq stat %d\n", stat);
519 break;
520 }
521 }
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200522
523 return count ? IRQ_HANDLED : IRQ_NONE;
524}
525
526static struct i2c_algorithm i2c_davinci_algo = {
527 .master_xfer = i2c_davinci_xfer,
528 .functionality = i2c_davinci_func,
529};
530
531static int davinci_i2c_probe(struct platform_device *pdev)
532{
533 struct davinci_i2c_dev *dev;
534 struct i2c_adapter *adap;
535 struct resource *mem, *irq, *ioarea;
536 int r;
537
538 /* NOTE: driver uses the static register mapping */
539 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
540 if (!mem) {
541 dev_err(&pdev->dev, "no mem resource?\n");
542 return -ENODEV;
543 }
544
545 irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
546 if (!irq) {
547 dev_err(&pdev->dev, "no irq resource?\n");
548 return -ENODEV;
549 }
550
Julia Lawall59330822009-07-05 08:37:50 +0200551 ioarea = request_mem_region(mem->start, resource_size(mem),
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200552 pdev->name);
553 if (!ioarea) {
554 dev_err(&pdev->dev, "I2C region already claimed\n");
555 return -EBUSY;
556 }
557
558 dev = kzalloc(sizeof(struct davinci_i2c_dev), GFP_KERNEL);
559 if (!dev) {
560 r = -ENOMEM;
561 goto err_release_region;
562 }
563
Troy Kisky2e743782008-07-14 22:38:21 +0200564 init_completion(&dev->cmd_complete);
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200565 dev->dev = get_device(&pdev->dev);
566 dev->irq = irq->start;
567 platform_set_drvdata(pdev, dev);
568
Kevin Hilmane164dde2009-07-06 15:48:35 -0700569 dev->clk = clk_get(&pdev->dev, NULL);
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200570 if (IS_ERR(dev->clk)) {
571 r = -ENODEV;
572 goto err_free_mem;
573 }
574 clk_enable(dev->clk);
575
Chaithrika U Sc062a252010-01-06 14:54:57 +0530576 dev->base = ioremap(mem->start, resource_size(mem));
577 if (!dev->base) {
578 r = -EBUSY;
579 goto err_mem_ioremap;
580 }
581
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200582 i2c_davinci_init(dev);
583
584 r = request_irq(dev->irq, i2c_davinci_isr, 0, pdev->name, dev);
585 if (r) {
586 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
587 goto err_unuse_clocks;
588 }
589
590 adap = &dev->adapter;
591 i2c_set_adapdata(adap, dev);
592 adap->owner = THIS_MODULE;
593 adap->class = I2C_CLASS_HWMON;
594 strlcpy(adap->name, "DaVinci I2C adapter", sizeof(adap->name));
595 adap->algo = &i2c_davinci_algo;
596 adap->dev.parent = &pdev->dev;
Jean Delvare98a679c2009-03-28 21:34:43 +0100597 adap->timeout = DAVINCI_I2C_TIMEOUT;
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200598
599 adap->nr = pdev->id;
600 r = i2c_add_numbered_adapter(adap);
601 if (r) {
602 dev_err(&pdev->dev, "failure adding adapter\n");
603 goto err_free_irq;
604 }
605
606 return 0;
607
608err_free_irq:
609 free_irq(dev->irq, dev);
610err_unuse_clocks:
Chaithrika U Sc062a252010-01-06 14:54:57 +0530611 iounmap(dev->base);
612err_mem_ioremap:
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200613 clk_disable(dev->clk);
614 clk_put(dev->clk);
615 dev->clk = NULL;
616err_free_mem:
617 platform_set_drvdata(pdev, NULL);
618 put_device(&pdev->dev);
619 kfree(dev);
620err_release_region:
Julia Lawall59330822009-07-05 08:37:50 +0200621 release_mem_region(mem->start, resource_size(mem));
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200622
623 return r;
624}
625
626static int davinci_i2c_remove(struct platform_device *pdev)
627{
628 struct davinci_i2c_dev *dev = platform_get_drvdata(pdev);
629 struct resource *mem;
630
631 platform_set_drvdata(pdev, NULL);
632 i2c_del_adapter(&dev->adapter);
633 put_device(&pdev->dev);
634
635 clk_disable(dev->clk);
636 clk_put(dev->clk);
637 dev->clk = NULL;
638
639 davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, 0);
640 free_irq(IRQ_I2C, dev);
Chaithrika U Sc062a252010-01-06 14:54:57 +0530641 iounmap(dev->base);
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200642 kfree(dev);
643
644 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
Julia Lawall59330822009-07-05 08:37:50 +0200645 release_mem_region(mem->start, resource_size(mem));
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200646 return 0;
647}
648
Chaithrika U S68f15de2010-01-06 14:54:59 +0530649#ifdef CONFIG_PM
650static int davinci_i2c_suspend(struct device *dev)
651{
652 struct platform_device *pdev = to_platform_device(dev);
653 struct davinci_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
654
655 /* put I2C into reset */
656 davinci_i2c_reset_ctrl(i2c_dev, 0);
657 clk_disable(i2c_dev->clk);
658
659 return 0;
660}
661
662static int davinci_i2c_resume(struct device *dev)
663{
664 struct platform_device *pdev = to_platform_device(dev);
665 struct davinci_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
666
667 clk_enable(i2c_dev->clk);
668 /* take I2C out of reset */
669 davinci_i2c_reset_ctrl(i2c_dev, 1);
670
671 return 0;
672}
673
674static const struct dev_pm_ops davinci_i2c_pm = {
675 .suspend = davinci_i2c_suspend,
676 .resume = davinci_i2c_resume,
677};
678
679#define davinci_i2c_pm_ops (&davinci_i2c_pm)
680#else
681#define davinci_i2c_pm_ops NULL
682#endif
683
Kay Sieversadd8eda2008-04-22 22:16:49 +0200684/* work with hotplug and coldplug */
685MODULE_ALIAS("platform:i2c_davinci");
686
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200687static struct platform_driver davinci_i2c_driver = {
688 .probe = davinci_i2c_probe,
689 .remove = davinci_i2c_remove,
690 .driver = {
691 .name = "i2c_davinci",
692 .owner = THIS_MODULE,
Chaithrika U S68f15de2010-01-06 14:54:59 +0530693 .pm = davinci_i2c_pm_ops,
Vladimir Barinov95a7f102007-10-13 23:56:30 +0200694 },
695};
696
697/* I2C may be needed to bring up other drivers */
698static int __init davinci_i2c_init_driver(void)
699{
700 return platform_driver_register(&davinci_i2c_driver);
701}
702subsys_initcall(davinci_i2c_init_driver);
703
704static void __exit davinci_i2c_exit_driver(void)
705{
706 platform_driver_unregister(&davinci_i2c_driver);
707}
708module_exit(davinci_i2c_exit_driver);
709
710MODULE_AUTHOR("Texas Instruments India");
711MODULE_DESCRIPTION("TI DaVinci I2C bus adapter");
712MODULE_LICENSE("GPL");