blob: eeb1915c59e369cf464cc9cc332bf14b05e8eb42 [file] [log] [blame]
Baruch Siach1ab52cf2009-06-22 16:36:29 +03001/*
2 * Synopsys Designware I2C adapter driver (master only).
3 *
4 * Based on the TI DAVINCI I2C adapter driver.
5 *
6 * Copyright (C) 2006 Texas Instruments.
7 * Copyright (C) 2007 MontaVista Software Inc.
8 * Copyright (C) 2009 Provigent Ltd.
9 *
10 * ----------------------------------------------------------------------------
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 * ----------------------------------------------------------------------------
26 *
27 */
28#include <linux/kernel.h>
29#include <linux/module.h>
30#include <linux/delay.h>
31#include <linux/i2c.h>
32#include <linux/clk.h>
33#include <linux/errno.h>
34#include <linux/sched.h>
35#include <linux/err.h>
36#include <linux/interrupt.h>
37#include <linux/platform_device.h>
38#include <linux/io.h>
39
40/*
41 * Registers offset
42 */
43#define DW_IC_CON 0x0
44#define DW_IC_TAR 0x4
45#define DW_IC_DATA_CMD 0x10
46#define DW_IC_SS_SCL_HCNT 0x14
47#define DW_IC_SS_SCL_LCNT 0x18
48#define DW_IC_FS_SCL_HCNT 0x1c
49#define DW_IC_FS_SCL_LCNT 0x20
50#define DW_IC_INTR_STAT 0x2c
51#define DW_IC_INTR_MASK 0x30
Shinya Kuribayashie28000a2009-11-06 21:44:37 +090052#define DW_IC_RAW_INTR_STAT 0x34
Baruch Siach1ab52cf2009-06-22 16:36:29 +030053#define DW_IC_CLR_INTR 0x40
Shinya Kuribayashie28000a2009-11-06 21:44:37 +090054#define DW_IC_CLR_RX_UNDER 0x44
55#define DW_IC_CLR_RX_OVER 0x48
56#define DW_IC_CLR_TX_OVER 0x4c
57#define DW_IC_CLR_RD_REQ 0x50
58#define DW_IC_CLR_TX_ABRT 0x54
59#define DW_IC_CLR_RX_DONE 0x58
60#define DW_IC_CLR_ACTIVITY 0x5c
61#define DW_IC_CLR_STOP_DET 0x60
62#define DW_IC_CLR_START_DET 0x64
63#define DW_IC_CLR_GEN_CALL 0x68
Baruch Siach1ab52cf2009-06-22 16:36:29 +030064#define DW_IC_ENABLE 0x6c
65#define DW_IC_STATUS 0x70
66#define DW_IC_TXFLR 0x74
67#define DW_IC_RXFLR 0x78
68#define DW_IC_COMP_PARAM_1 0xf4
69#define DW_IC_TX_ABRT_SOURCE 0x80
70
71#define DW_IC_CON_MASTER 0x1
72#define DW_IC_CON_SPEED_STD 0x2
73#define DW_IC_CON_SPEED_FAST 0x4
74#define DW_IC_CON_10BITADDR_MASTER 0x10
75#define DW_IC_CON_RESTART_EN 0x20
76#define DW_IC_CON_SLAVE_DISABLE 0x40
77
Shinya Kuribayashie28000a2009-11-06 21:44:37 +090078#define DW_IC_INTR_RX_UNDER 0x001
79#define DW_IC_INTR_RX_OVER 0x002
80#define DW_IC_INTR_RX_FULL 0x004
81#define DW_IC_INTR_TX_OVER 0x008
82#define DW_IC_INTR_TX_EMPTY 0x010
83#define DW_IC_INTR_RD_REQ 0x020
84#define DW_IC_INTR_TX_ABRT 0x040
85#define DW_IC_INTR_RX_DONE 0x080
86#define DW_IC_INTR_ACTIVITY 0x100
Baruch Siach1ab52cf2009-06-22 16:36:29 +030087#define DW_IC_INTR_STOP_DET 0x200
Shinya Kuribayashie28000a2009-11-06 21:44:37 +090088#define DW_IC_INTR_START_DET 0x400
89#define DW_IC_INTR_GEN_CALL 0x800
Baruch Siach1ab52cf2009-06-22 16:36:29 +030090
91#define DW_IC_STATUS_ACTIVITY 0x1
92
93#define DW_IC_ERR_TX_ABRT 0x1
94
95/*
96 * status codes
97 */
98#define STATUS_IDLE 0x0
99#define STATUS_WRITE_IN_PROGRESS 0x1
100#define STATUS_READ_IN_PROGRESS 0x2
101
102#define TIMEOUT 20 /* ms */
103
104/*
105 * hardware abort codes from the DW_IC_TX_ABRT_SOURCE register
106 *
107 * only expected abort codes are listed here
108 * refer to the datasheet for the full list
109 */
110#define ABRT_7B_ADDR_NOACK 0
111#define ABRT_10ADDR1_NOACK 1
112#define ABRT_10ADDR2_NOACK 2
113#define ABRT_TXDATA_NOACK 3
114#define ABRT_GCALL_NOACK 4
115#define ABRT_GCALL_READ 5
116#define ABRT_SBYTE_ACKDET 7
117#define ABRT_SBYTE_NORSTRT 9
118#define ABRT_10B_RD_NORSTRT 10
119#define ARB_MASTER_DIS 11
120#define ARB_LOST 12
121
122static char *abort_sources[] = {
123 [ABRT_7B_ADDR_NOACK] =
124 "slave address not acknowledged (7bit mode)",
125 [ABRT_10ADDR1_NOACK] =
126 "first address byte not acknowledged (10bit mode)",
127 [ABRT_10ADDR2_NOACK] =
128 "second address byte not acknowledged (10bit mode)",
129 [ABRT_TXDATA_NOACK] =
130 "data not acknowledged",
131 [ABRT_GCALL_NOACK] =
132 "no acknowledgement for a general call",
133 [ABRT_GCALL_READ] =
134 "read after general call",
135 [ABRT_SBYTE_ACKDET] =
136 "start byte acknowledged",
137 [ABRT_SBYTE_NORSTRT] =
138 "trying to send start byte when restart is disabled",
139 [ABRT_10B_RD_NORSTRT] =
140 "trying to read when restart is disabled (10bit mode)",
141 [ARB_MASTER_DIS] =
142 "trying to use disabled adapter",
143 [ARB_LOST] =
144 "lost arbitration",
145};
146
147/**
148 * struct dw_i2c_dev - private i2c-designware data
149 * @dev: driver model device node
150 * @base: IO registers pointer
151 * @cmd_complete: tx completion indicator
152 * @pump_msg: continue in progress transfers
153 * @lock: protect this struct and IO registers
154 * @clk: input reference clock
155 * @cmd_err: run time hadware error code
156 * @msgs: points to an array of messages currently being transfered
157 * @msgs_num: the number of elements in msgs
158 * @msg_write_idx: the element index of the current tx message in the msgs
159 * array
160 * @tx_buf_len: the length of the current tx buffer
161 * @tx_buf: the current tx buffer
162 * @msg_read_idx: the element index of the current rx message in the msgs
163 * array
164 * @rx_buf_len: the length of the current rx buffer
165 * @rx_buf: the current rx buffer
166 * @msg_err: error status of the current transfer
167 * @status: i2c master status, one of STATUS_*
168 * @abort_source: copy of the TX_ABRT_SOURCE register
169 * @irq: interrupt number for the i2c master
170 * @adapter: i2c subsystem adapter node
171 * @tx_fifo_depth: depth of the hardware tx fifo
172 * @rx_fifo_depth: depth of the hardware rx fifo
173 */
174struct dw_i2c_dev {
175 struct device *dev;
176 void __iomem *base;
177 struct completion cmd_complete;
178 struct tasklet_struct pump_msg;
179 struct mutex lock;
180 struct clk *clk;
181 int cmd_err;
182 struct i2c_msg *msgs;
183 int msgs_num;
184 int msg_write_idx;
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900185 u32 tx_buf_len;
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300186 u8 *tx_buf;
187 int msg_read_idx;
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900188 u32 rx_buf_len;
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300189 u8 *rx_buf;
190 int msg_err;
191 unsigned int status;
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900192 u32 abort_source;
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300193 int irq;
194 struct i2c_adapter adapter;
195 unsigned int tx_fifo_depth;
196 unsigned int rx_fifo_depth;
197};
198
199/**
200 * i2c_dw_init() - initialize the designware i2c master hardware
201 * @dev: device private data
202 *
203 * This functions configures and enables the I2C master.
204 * This function is called during I2C init function, and in case of timeout at
205 * run time.
206 */
207static void i2c_dw_init(struct dw_i2c_dev *dev)
208{
209 u32 input_clock_khz = clk_get_rate(dev->clk) / 1000;
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900210 u32 ic_con;
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300211
212 /* Disable the adapter */
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900213 writel(0, dev->base + DW_IC_ENABLE);
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300214
215 /* set standard and fast speed deviders for high/low periods */
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900216 writel((input_clock_khz * 40 / 10000)+1, /* std speed high, 4us */
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300217 dev->base + DW_IC_SS_SCL_HCNT);
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900218 writel((input_clock_khz * 47 / 10000)+1, /* std speed low, 4.7us */
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300219 dev->base + DW_IC_SS_SCL_LCNT);
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900220 writel((input_clock_khz * 6 / 10000)+1, /* fast speed high, 0.6us */
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300221 dev->base + DW_IC_FS_SCL_HCNT);
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900222 writel((input_clock_khz * 13 / 10000)+1, /* fast speed low, 1.3us */
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300223 dev->base + DW_IC_FS_SCL_LCNT);
224
225 /* configure the i2c master */
226 ic_con = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
227 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900228 writel(ic_con, dev->base + DW_IC_CON);
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300229}
230
231/*
232 * Waiting for bus not busy
233 */
234static int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
235{
236 int timeout = TIMEOUT;
237
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900238 while (readl(dev->base + DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) {
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300239 if (timeout <= 0) {
240 dev_warn(dev->dev, "timeout waiting for bus ready\n");
241 return -ETIMEDOUT;
242 }
243 timeout--;
244 mdelay(1);
245 }
246
247 return 0;
248}
249
250/*
251 * Initiate low level master read/write transaction.
252 * This function is called from i2c_dw_xfer when starting a transfer.
253 * This function is also called from dw_i2c_pump_msg to continue a transfer
254 * that is longer than the size of the TX FIFO.
255 */
256static void
257i2c_dw_xfer_msg(struct i2c_adapter *adap)
258{
259 struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
260 struct i2c_msg *msgs = dev->msgs;
261 int num = dev->msgs_num;
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900262 u32 ic_con, intr_mask;
263 int tx_limit = dev->tx_fifo_depth - readl(dev->base + DW_IC_TXFLR);
264 int rx_limit = dev->rx_fifo_depth - readl(dev->base + DW_IC_RXFLR);
265 u32 addr = msgs[dev->msg_write_idx].addr;
266 u32 buf_len = dev->tx_buf_len;
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300267
268 if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
269 /* Disable the adapter */
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900270 writel(0, dev->base + DW_IC_ENABLE);
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300271
272 /* set the slave (target) address */
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900273 writel(msgs[dev->msg_write_idx].addr, dev->base + DW_IC_TAR);
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300274
275 /* if the slave address is ten bit address, enable 10BITADDR */
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900276 ic_con = readl(dev->base + DW_IC_CON);
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300277 if (msgs[dev->msg_write_idx].flags & I2C_M_TEN)
278 ic_con |= DW_IC_CON_10BITADDR_MASTER;
279 else
280 ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900281 writel(ic_con, dev->base + DW_IC_CON);
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300282
283 /* Enable the adapter */
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900284 writel(1, dev->base + DW_IC_ENABLE);
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300285 }
286
287 for (; dev->msg_write_idx < num; dev->msg_write_idx++) {
288 /* if target address has changed, we need to
289 * reprogram the target address in the i2c
290 * adapter when we are done with this transfer
291 */
292 if (msgs[dev->msg_write_idx].addr != addr)
293 return;
294
295 if (msgs[dev->msg_write_idx].len == 0) {
296 dev_err(dev->dev,
297 "%s: invalid message length\n", __func__);
298 dev->msg_err = -EINVAL;
299 return;
300 }
301
302 if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
303 /* new i2c_msg */
304 dev->tx_buf = msgs[dev->msg_write_idx].buf;
305 buf_len = msgs[dev->msg_write_idx].len;
306 }
307
308 while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) {
309 if (msgs[dev->msg_write_idx].flags & I2C_M_RD) {
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900310 writel(0x100, dev->base + DW_IC_DATA_CMD);
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300311 rx_limit--;
312 } else
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900313 writel(*(dev->tx_buf++),
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300314 dev->base + DW_IC_DATA_CMD);
315 tx_limit--; buf_len--;
316 }
317 }
318
319 intr_mask = DW_IC_INTR_STOP_DET | DW_IC_INTR_TX_ABRT;
320 if (buf_len > 0) { /* more bytes to be written */
321 intr_mask |= DW_IC_INTR_TX_EMPTY;
322 dev->status |= STATUS_WRITE_IN_PROGRESS;
323 } else
324 dev->status &= ~STATUS_WRITE_IN_PROGRESS;
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900325 writel(intr_mask, dev->base + DW_IC_INTR_MASK);
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300326
327 dev->tx_buf_len = buf_len;
328}
329
330static void
331i2c_dw_read(struct i2c_adapter *adap)
332{
333 struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
334 struct i2c_msg *msgs = dev->msgs;
335 int num = dev->msgs_num;
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900336 u32 addr = msgs[dev->msg_read_idx].addr;
337 int rx_valid = readl(dev->base + DW_IC_RXFLR);
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300338
339 for (; dev->msg_read_idx < num; dev->msg_read_idx++) {
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900340 u32 len;
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300341 u8 *buf;
342
343 if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD))
344 continue;
345
346 /* different i2c client, reprogram the i2c adapter */
347 if (msgs[dev->msg_read_idx].addr != addr)
348 return;
349
350 if (!(dev->status & STATUS_READ_IN_PROGRESS)) {
351 len = msgs[dev->msg_read_idx].len;
352 buf = msgs[dev->msg_read_idx].buf;
353 } else {
354 len = dev->rx_buf_len;
355 buf = dev->rx_buf;
356 }
357
358 for (; len > 0 && rx_valid > 0; len--, rx_valid--)
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900359 *buf++ = readl(dev->base + DW_IC_DATA_CMD);
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300360
361 if (len > 0) {
362 dev->status |= STATUS_READ_IN_PROGRESS;
363 dev->rx_buf_len = len;
364 dev->rx_buf = buf;
365 return;
366 } else
367 dev->status &= ~STATUS_READ_IN_PROGRESS;
368 }
369}
370
371/*
372 * Prepare controller for a transaction and call i2c_dw_xfer_msg
373 */
374static int
375i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
376{
377 struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
378 int ret;
379
380 dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
381
382 mutex_lock(&dev->lock);
383
384 INIT_COMPLETION(dev->cmd_complete);
385 dev->msgs = msgs;
386 dev->msgs_num = num;
387 dev->cmd_err = 0;
388 dev->msg_write_idx = 0;
389 dev->msg_read_idx = 0;
390 dev->msg_err = 0;
391 dev->status = STATUS_IDLE;
392
393 ret = i2c_dw_wait_bus_not_busy(dev);
394 if (ret < 0)
395 goto done;
396
397 /* start the transfers */
398 i2c_dw_xfer_msg(adap);
399
400 /* wait for tx to complete */
401 ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete, HZ);
402 if (ret == 0) {
403 dev_err(dev->dev, "controller timed out\n");
404 i2c_dw_init(dev);
405 ret = -ETIMEDOUT;
406 goto done;
407 } else if (ret < 0)
408 goto done;
409
410 if (dev->msg_err) {
411 ret = dev->msg_err;
412 goto done;
413 }
414
415 /* no error */
416 if (likely(!dev->cmd_err)) {
417 /* read rx fifo, and disable the adapter */
418 do {
419 i2c_dw_read(adap);
420 } while (dev->status & STATUS_READ_IN_PROGRESS);
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900421 writel(0, dev->base + DW_IC_ENABLE);
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300422 ret = num;
423 goto done;
424 }
425
426 /* We have an error */
427 if (dev->cmd_err == DW_IC_ERR_TX_ABRT) {
428 unsigned long abort_source = dev->abort_source;
429 int i;
430
431 for_each_bit(i, &abort_source, ARRAY_SIZE(abort_sources)) {
432 dev_err(dev->dev, "%s: %s\n", __func__, abort_sources[i]);
433 }
434 }
435 ret = -EIO;
436
437done:
438 mutex_unlock(&dev->lock);
439
440 return ret;
441}
442
443static u32 i2c_dw_func(struct i2c_adapter *adap)
444{
445 return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR;
446}
447
448static void dw_i2c_pump_msg(unsigned long data)
449{
450 struct dw_i2c_dev *dev = (struct dw_i2c_dev *) data;
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900451 u32 intr_mask;
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300452
453 i2c_dw_read(&dev->adapter);
454 i2c_dw_xfer_msg(&dev->adapter);
455
456 intr_mask = DW_IC_INTR_STOP_DET | DW_IC_INTR_TX_ABRT;
457 if (dev->status & STATUS_WRITE_IN_PROGRESS)
458 intr_mask |= DW_IC_INTR_TX_EMPTY;
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900459 writel(intr_mask, dev->base + DW_IC_INTR_MASK);
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300460}
461
Shinya Kuribayashie28000a2009-11-06 21:44:37 +0900462static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev)
463{
464 u32 stat;
465
466 /*
467 * The IC_INTR_STAT register just indicates "enabled" interrupts.
468 * Ths unmasked raw version of interrupt status bits are available
469 * in the IC_RAW_INTR_STAT register.
470 *
471 * That is,
472 * stat = readl(IC_INTR_STAT);
473 * equals to,
474 * stat = readl(IC_RAW_INTR_STAT) & readl(IC_INTR_MASK);
475 *
476 * The raw version might be useful for debugging purposes.
477 */
478 stat = readl(dev->base + DW_IC_INTR_STAT);
479
480 /*
481 * Do not use the IC_CLR_INTR register to clear interrupts, or
482 * you'll miss some interrupts, triggered during the period from
483 * readl(IC_INTR_STAT) to readl(IC_CLR_INTR).
484 *
485 * Instead, use the separately-prepared IC_CLR_* registers.
486 */
487 if (stat & DW_IC_INTR_RX_UNDER)
488 readl(dev->base + DW_IC_CLR_RX_UNDER);
489 if (stat & DW_IC_INTR_RX_OVER)
490 readl(dev->base + DW_IC_CLR_RX_OVER);
491 if (stat & DW_IC_INTR_TX_OVER)
492 readl(dev->base + DW_IC_CLR_TX_OVER);
493 if (stat & DW_IC_INTR_RD_REQ)
494 readl(dev->base + DW_IC_CLR_RD_REQ);
495 if (stat & DW_IC_INTR_TX_ABRT) {
496 /*
497 * The IC_TX_ABRT_SOURCE register is cleared whenever
498 * the IC_CLR_TX_ABRT is read. Preserve it beforehand.
499 */
500 dev->abort_source = readl(dev->base + DW_IC_TX_ABRT_SOURCE);
501 readl(dev->base + DW_IC_CLR_TX_ABRT);
502 }
503 if (stat & DW_IC_INTR_RX_DONE)
504 readl(dev->base + DW_IC_CLR_RX_DONE);
505 if (stat & DW_IC_INTR_ACTIVITY)
506 readl(dev->base + DW_IC_CLR_ACTIVITY);
507 if (stat & DW_IC_INTR_STOP_DET)
508 readl(dev->base + DW_IC_CLR_STOP_DET);
509 if (stat & DW_IC_INTR_START_DET)
510 readl(dev->base + DW_IC_CLR_START_DET);
511 if (stat & DW_IC_INTR_GEN_CALL)
512 readl(dev->base + DW_IC_CLR_GEN_CALL);
513
514 return stat;
515}
516
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300517/*
518 * Interrupt service routine. This gets called whenever an I2C interrupt
519 * occurs.
520 */
521static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
522{
523 struct dw_i2c_dev *dev = dev_id;
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900524 u32 stat;
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300525
Shinya Kuribayashie28000a2009-11-06 21:44:37 +0900526 stat = i2c_dw_read_clear_intrbits(dev);
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300527 dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);
Shinya Kuribayashie28000a2009-11-06 21:44:37 +0900528
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300529 if (stat & DW_IC_INTR_TX_ABRT) {
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300530 dev->cmd_err |= DW_IC_ERR_TX_ABRT;
531 dev->status = STATUS_IDLE;
532 } else if (stat & DW_IC_INTR_TX_EMPTY)
533 tasklet_schedule(&dev->pump_msg);
534
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900535 writel(0, dev->base + DW_IC_INTR_MASK); /* disable interrupts */
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300536 if (stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET))
537 complete(&dev->cmd_complete);
538
539 return IRQ_HANDLED;
540}
541
542static struct i2c_algorithm i2c_dw_algo = {
543 .master_xfer = i2c_dw_xfer,
544 .functionality = i2c_dw_func,
545};
546
547static int __devinit dw_i2c_probe(struct platform_device *pdev)
548{
549 struct dw_i2c_dev *dev;
550 struct i2c_adapter *adap;
551 struct resource *mem, *irq, *ioarea;
552 int r;
553
554 /* NOTE: driver uses the static register mapping */
555 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
556 if (!mem) {
557 dev_err(&pdev->dev, "no mem resource?\n");
558 return -EINVAL;
559 }
560
561 irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
562 if (!irq) {
563 dev_err(&pdev->dev, "no irq resource?\n");
564 return -EINVAL;
565 }
566
567 ioarea = request_mem_region(mem->start, resource_size(mem),
568 pdev->name);
569 if (!ioarea) {
570 dev_err(&pdev->dev, "I2C region already claimed\n");
571 return -EBUSY;
572 }
573
574 dev = kzalloc(sizeof(struct dw_i2c_dev), GFP_KERNEL);
575 if (!dev) {
576 r = -ENOMEM;
577 goto err_release_region;
578 }
579
580 init_completion(&dev->cmd_complete);
581 tasklet_init(&dev->pump_msg, dw_i2c_pump_msg, (unsigned long) dev);
582 mutex_init(&dev->lock);
583 dev->dev = get_device(&pdev->dev);
584 dev->irq = irq->start;
585 platform_set_drvdata(pdev, dev);
586
587 dev->clk = clk_get(&pdev->dev, NULL);
588 if (IS_ERR(dev->clk)) {
589 r = -ENODEV;
590 goto err_free_mem;
591 }
592 clk_enable(dev->clk);
593
594 dev->base = ioremap(mem->start, resource_size(mem));
595 if (dev->base == NULL) {
596 dev_err(&pdev->dev, "failure mapping io resources\n");
597 r = -EBUSY;
598 goto err_unuse_clocks;
599 }
600 {
601 u32 param1 = readl(dev->base + DW_IC_COMP_PARAM_1);
602
603 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
604 dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1;
605 }
606 i2c_dw_init(dev);
607
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900608 writel(0, dev->base + DW_IC_INTR_MASK); /* disable IRQ */
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300609 r = request_irq(dev->irq, i2c_dw_isr, 0, pdev->name, dev);
610 if (r) {
611 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
612 goto err_iounmap;
613 }
614
615 adap = &dev->adapter;
616 i2c_set_adapdata(adap, dev);
617 adap->owner = THIS_MODULE;
618 adap->class = I2C_CLASS_HWMON;
619 strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
620 sizeof(adap->name));
621 adap->algo = &i2c_dw_algo;
622 adap->dev.parent = &pdev->dev;
623
624 adap->nr = pdev->id;
625 r = i2c_add_numbered_adapter(adap);
626 if (r) {
627 dev_err(&pdev->dev, "failure adding adapter\n");
628 goto err_free_irq;
629 }
630
631 return 0;
632
633err_free_irq:
634 free_irq(dev->irq, dev);
635err_iounmap:
636 iounmap(dev->base);
637err_unuse_clocks:
638 clk_disable(dev->clk);
639 clk_put(dev->clk);
640 dev->clk = NULL;
641err_free_mem:
642 platform_set_drvdata(pdev, NULL);
643 put_device(&pdev->dev);
644 kfree(dev);
645err_release_region:
646 release_mem_region(mem->start, resource_size(mem));
647
648 return r;
649}
650
651static int __devexit dw_i2c_remove(struct platform_device *pdev)
652{
653 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
654 struct resource *mem;
655
656 platform_set_drvdata(pdev, NULL);
657 i2c_del_adapter(&dev->adapter);
658 put_device(&pdev->dev);
659
660 clk_disable(dev->clk);
661 clk_put(dev->clk);
662 dev->clk = NULL;
663
Shinya Kuribayashied5e1dd2009-11-06 21:43:52 +0900664 writel(0, dev->base + DW_IC_ENABLE);
Baruch Siach1ab52cf2009-06-22 16:36:29 +0300665 free_irq(dev->irq, dev);
666 kfree(dev);
667
668 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
669 release_mem_region(mem->start, resource_size(mem));
670 return 0;
671}
672
673/* work with hotplug and coldplug */
674MODULE_ALIAS("platform:i2c_designware");
675
676static struct platform_driver dw_i2c_driver = {
677 .remove = __devexit_p(dw_i2c_remove),
678 .driver = {
679 .name = "i2c_designware",
680 .owner = THIS_MODULE,
681 },
682};
683
684static int __init dw_i2c_init_driver(void)
685{
686 return platform_driver_probe(&dw_i2c_driver, dw_i2c_probe);
687}
688module_init(dw_i2c_init_driver);
689
690static void __exit dw_i2c_exit_driver(void)
691{
692 platform_driver_unregister(&dw_i2c_driver);
693}
694module_exit(dw_i2c_exit_driver);
695
696MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
697MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
698MODULE_LICENSE("GPL");