Commit | Line | Data |
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1ab52cf9 BS |
1 | /* |
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 | |
e28000a3 | 52 | #define DW_IC_RAW_INTR_STAT 0x34 |
4cb6d1d6 SK |
53 | #define DW_IC_RX_TL 0x38 |
54 | #define DW_IC_TX_TL 0x3c | |
1ab52cf9 | 55 | #define DW_IC_CLR_INTR 0x40 |
e28000a3 SK |
56 | #define DW_IC_CLR_RX_UNDER 0x44 |
57 | #define DW_IC_CLR_RX_OVER 0x48 | |
58 | #define DW_IC_CLR_TX_OVER 0x4c | |
59 | #define DW_IC_CLR_RD_REQ 0x50 | |
60 | #define DW_IC_CLR_TX_ABRT 0x54 | |
61 | #define DW_IC_CLR_RX_DONE 0x58 | |
62 | #define DW_IC_CLR_ACTIVITY 0x5c | |
63 | #define DW_IC_CLR_STOP_DET 0x60 | |
64 | #define DW_IC_CLR_START_DET 0x64 | |
65 | #define DW_IC_CLR_GEN_CALL 0x68 | |
1ab52cf9 BS |
66 | #define DW_IC_ENABLE 0x6c |
67 | #define DW_IC_STATUS 0x70 | |
68 | #define DW_IC_TXFLR 0x74 | |
69 | #define DW_IC_RXFLR 0x78 | |
70 | #define DW_IC_COMP_PARAM_1 0xf4 | |
71 | #define DW_IC_TX_ABRT_SOURCE 0x80 | |
72 | ||
73 | #define DW_IC_CON_MASTER 0x1 | |
74 | #define DW_IC_CON_SPEED_STD 0x2 | |
75 | #define DW_IC_CON_SPEED_FAST 0x4 | |
76 | #define DW_IC_CON_10BITADDR_MASTER 0x10 | |
77 | #define DW_IC_CON_RESTART_EN 0x20 | |
78 | #define DW_IC_CON_SLAVE_DISABLE 0x40 | |
79 | ||
e28000a3 SK |
80 | #define DW_IC_INTR_RX_UNDER 0x001 |
81 | #define DW_IC_INTR_RX_OVER 0x002 | |
82 | #define DW_IC_INTR_RX_FULL 0x004 | |
83 | #define DW_IC_INTR_TX_OVER 0x008 | |
84 | #define DW_IC_INTR_TX_EMPTY 0x010 | |
85 | #define DW_IC_INTR_RD_REQ 0x020 | |
86 | #define DW_IC_INTR_TX_ABRT 0x040 | |
87 | #define DW_IC_INTR_RX_DONE 0x080 | |
88 | #define DW_IC_INTR_ACTIVITY 0x100 | |
1ab52cf9 | 89 | #define DW_IC_INTR_STOP_DET 0x200 |
e28000a3 SK |
90 | #define DW_IC_INTR_START_DET 0x400 |
91 | #define DW_IC_INTR_GEN_CALL 0x800 | |
1ab52cf9 | 92 | |
201d6a70 SK |
93 | #define DW_IC_INTR_DEFAULT_MASK (DW_IC_INTR_RX_FULL | \ |
94 | DW_IC_INTR_TX_EMPTY | \ | |
95 | DW_IC_INTR_TX_ABRT | \ | |
96 | DW_IC_INTR_STOP_DET) | |
97 | ||
1ab52cf9 BS |
98 | #define DW_IC_STATUS_ACTIVITY 0x1 |
99 | ||
100 | #define DW_IC_ERR_TX_ABRT 0x1 | |
101 | ||
102 | /* | |
103 | * status codes | |
104 | */ | |
105 | #define STATUS_IDLE 0x0 | |
106 | #define STATUS_WRITE_IN_PROGRESS 0x1 | |
107 | #define STATUS_READ_IN_PROGRESS 0x2 | |
108 | ||
109 | #define TIMEOUT 20 /* ms */ | |
110 | ||
111 | /* | |
112 | * hardware abort codes from the DW_IC_TX_ABRT_SOURCE register | |
113 | * | |
114 | * only expected abort codes are listed here | |
115 | * refer to the datasheet for the full list | |
116 | */ | |
117 | #define ABRT_7B_ADDR_NOACK 0 | |
118 | #define ABRT_10ADDR1_NOACK 1 | |
119 | #define ABRT_10ADDR2_NOACK 2 | |
120 | #define ABRT_TXDATA_NOACK 3 | |
121 | #define ABRT_GCALL_NOACK 4 | |
122 | #define ABRT_GCALL_READ 5 | |
123 | #define ABRT_SBYTE_ACKDET 7 | |
124 | #define ABRT_SBYTE_NORSTRT 9 | |
125 | #define ABRT_10B_RD_NORSTRT 10 | |
126 | #define ARB_MASTER_DIS 11 | |
127 | #define ARB_LOST 12 | |
128 | ||
129 | static char *abort_sources[] = { | |
130 | [ABRT_7B_ADDR_NOACK] = | |
131 | "slave address not acknowledged (7bit mode)", | |
132 | [ABRT_10ADDR1_NOACK] = | |
133 | "first address byte not acknowledged (10bit mode)", | |
134 | [ABRT_10ADDR2_NOACK] = | |
135 | "second address byte not acknowledged (10bit mode)", | |
136 | [ABRT_TXDATA_NOACK] = | |
137 | "data not acknowledged", | |
138 | [ABRT_GCALL_NOACK] = | |
139 | "no acknowledgement for a general call", | |
140 | [ABRT_GCALL_READ] = | |
141 | "read after general call", | |
142 | [ABRT_SBYTE_ACKDET] = | |
143 | "start byte acknowledged", | |
144 | [ABRT_SBYTE_NORSTRT] = | |
145 | "trying to send start byte when restart is disabled", | |
146 | [ABRT_10B_RD_NORSTRT] = | |
147 | "trying to read when restart is disabled (10bit mode)", | |
148 | [ARB_MASTER_DIS] = | |
149 | "trying to use disabled adapter", | |
150 | [ARB_LOST] = | |
151 | "lost arbitration", | |
152 | }; | |
153 | ||
154 | /** | |
155 | * struct dw_i2c_dev - private i2c-designware data | |
156 | * @dev: driver model device node | |
157 | * @base: IO registers pointer | |
158 | * @cmd_complete: tx completion indicator | |
1ab52cf9 BS |
159 | * @lock: protect this struct and IO registers |
160 | * @clk: input reference clock | |
161 | * @cmd_err: run time hadware error code | |
162 | * @msgs: points to an array of messages currently being transfered | |
163 | * @msgs_num: the number of elements in msgs | |
164 | * @msg_write_idx: the element index of the current tx message in the msgs | |
165 | * array | |
166 | * @tx_buf_len: the length of the current tx buffer | |
167 | * @tx_buf: the current tx buffer | |
168 | * @msg_read_idx: the element index of the current rx message in the msgs | |
169 | * array | |
170 | * @rx_buf_len: the length of the current rx buffer | |
171 | * @rx_buf: the current rx buffer | |
172 | * @msg_err: error status of the current transfer | |
173 | * @status: i2c master status, one of STATUS_* | |
174 | * @abort_source: copy of the TX_ABRT_SOURCE register | |
175 | * @irq: interrupt number for the i2c master | |
176 | * @adapter: i2c subsystem adapter node | |
177 | * @tx_fifo_depth: depth of the hardware tx fifo | |
178 | * @rx_fifo_depth: depth of the hardware rx fifo | |
179 | */ | |
180 | struct dw_i2c_dev { | |
181 | struct device *dev; | |
182 | void __iomem *base; | |
183 | struct completion cmd_complete; | |
1ab52cf9 BS |
184 | struct mutex lock; |
185 | struct clk *clk; | |
186 | int cmd_err; | |
187 | struct i2c_msg *msgs; | |
188 | int msgs_num; | |
189 | int msg_write_idx; | |
ed5e1dd5 | 190 | u32 tx_buf_len; |
1ab52cf9 BS |
191 | u8 *tx_buf; |
192 | int msg_read_idx; | |
ed5e1dd5 | 193 | u32 rx_buf_len; |
1ab52cf9 BS |
194 | u8 *rx_buf; |
195 | int msg_err; | |
196 | unsigned int status; | |
ed5e1dd5 | 197 | u32 abort_source; |
1ab52cf9 BS |
198 | int irq; |
199 | struct i2c_adapter adapter; | |
200 | unsigned int tx_fifo_depth; | |
201 | unsigned int rx_fifo_depth; | |
202 | }; | |
203 | ||
d60c7e81 SK |
204 | static u32 |
205 | i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset) | |
206 | { | |
207 | /* | |
208 | * DesignWare I2C core doesn't seem to have solid strategy to meet | |
209 | * the tHD;STA timing spec. Configuring _HCNT based on tHIGH spec | |
210 | * will result in violation of the tHD;STA spec. | |
211 | */ | |
212 | if (cond) | |
213 | /* | |
214 | * Conditional expression: | |
215 | * | |
216 | * IC_[FS]S_SCL_HCNT + (1+4+3) >= IC_CLK * tHIGH | |
217 | * | |
218 | * This is based on the DW manuals, and represents an ideal | |
219 | * configuration. The resulting I2C bus speed will be | |
220 | * faster than any of the others. | |
221 | * | |
222 | * If your hardware is free from tHD;STA issue, try this one. | |
223 | */ | |
224 | return (ic_clk * tSYMBOL + 5000) / 10000 - 8 + offset; | |
225 | else | |
226 | /* | |
227 | * Conditional expression: | |
228 | * | |
229 | * IC_[FS]S_SCL_HCNT + 3 >= IC_CLK * (tHD;STA + tf) | |
230 | * | |
231 | * This is just experimental rule; the tHD;STA period turned | |
232 | * out to be proportinal to (_HCNT + 3). With this setting, | |
233 | * we could meet both tHIGH and tHD;STA timing specs. | |
234 | * | |
235 | * If unsure, you'd better to take this alternative. | |
236 | * | |
237 | * The reason why we need to take into account "tf" here, | |
238 | * is the same as described in i2c_dw_scl_lcnt(). | |
239 | */ | |
240 | return (ic_clk * (tSYMBOL + tf) + 5000) / 10000 - 3 + offset; | |
241 | } | |
242 | ||
243 | static u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset) | |
244 | { | |
245 | /* | |
246 | * Conditional expression: | |
247 | * | |
248 | * IC_[FS]S_SCL_LCNT + 1 >= IC_CLK * (tLOW + tf) | |
249 | * | |
250 | * DW I2C core starts counting the SCL CNTs for the LOW period | |
251 | * of the SCL clock (tLOW) as soon as it pulls the SCL line. | |
252 | * In order to meet the tLOW timing spec, we need to take into | |
253 | * account the fall time of SCL signal (tf). Default tf value | |
254 | * should be 0.3 us, for safety. | |
255 | */ | |
256 | return ((ic_clk * (tLOW + tf) + 5000) / 10000) - 1 + offset; | |
257 | } | |
258 | ||
1ab52cf9 BS |
259 | /** |
260 | * i2c_dw_init() - initialize the designware i2c master hardware | |
261 | * @dev: device private data | |
262 | * | |
263 | * This functions configures and enables the I2C master. | |
264 | * This function is called during I2C init function, and in case of timeout at | |
265 | * run time. | |
266 | */ | |
267 | static void i2c_dw_init(struct dw_i2c_dev *dev) | |
268 | { | |
269 | u32 input_clock_khz = clk_get_rate(dev->clk) / 1000; | |
d60c7e81 | 270 | u32 ic_con, hcnt, lcnt; |
1ab52cf9 BS |
271 | |
272 | /* Disable the adapter */ | |
ed5e1dd5 | 273 | writel(0, dev->base + DW_IC_ENABLE); |
1ab52cf9 BS |
274 | |
275 | /* set standard and fast speed deviders for high/low periods */ | |
d60c7e81 SK |
276 | |
277 | /* Standard-mode */ | |
278 | hcnt = i2c_dw_scl_hcnt(input_clock_khz, | |
279 | 40, /* tHD;STA = tHIGH = 4.0 us */ | |
280 | 3, /* tf = 0.3 us */ | |
281 | 0, /* 0: DW default, 1: Ideal */ | |
282 | 0); /* No offset */ | |
283 | lcnt = i2c_dw_scl_lcnt(input_clock_khz, | |
284 | 47, /* tLOW = 4.7 us */ | |
285 | 3, /* tf = 0.3 us */ | |
286 | 0); /* No offset */ | |
287 | writel(hcnt, dev->base + DW_IC_SS_SCL_HCNT); | |
288 | writel(lcnt, dev->base + DW_IC_SS_SCL_LCNT); | |
289 | dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt); | |
290 | ||
291 | /* Fast-mode */ | |
292 | hcnt = i2c_dw_scl_hcnt(input_clock_khz, | |
293 | 6, /* tHD;STA = tHIGH = 0.6 us */ | |
294 | 3, /* tf = 0.3 us */ | |
295 | 0, /* 0: DW default, 1: Ideal */ | |
296 | 0); /* No offset */ | |
297 | lcnt = i2c_dw_scl_lcnt(input_clock_khz, | |
298 | 13, /* tLOW = 1.3 us */ | |
299 | 3, /* tf = 0.3 us */ | |
300 | 0); /* No offset */ | |
301 | writel(hcnt, dev->base + DW_IC_FS_SCL_HCNT); | |
302 | writel(lcnt, dev->base + DW_IC_FS_SCL_LCNT); | |
303 | dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt); | |
1ab52cf9 | 304 | |
4cb6d1d6 SK |
305 | /* Configure Tx/Rx FIFO threshold levels */ |
306 | writel(dev->tx_fifo_depth - 1, dev->base + DW_IC_TX_TL); | |
307 | writel(0, dev->base + DW_IC_RX_TL); | |
308 | ||
1ab52cf9 BS |
309 | /* configure the i2c master */ |
310 | ic_con = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | | |
311 | DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST; | |
ed5e1dd5 | 312 | writel(ic_con, dev->base + DW_IC_CON); |
1ab52cf9 BS |
313 | } |
314 | ||
315 | /* | |
316 | * Waiting for bus not busy | |
317 | */ | |
318 | static int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev) | |
319 | { | |
320 | int timeout = TIMEOUT; | |
321 | ||
ed5e1dd5 | 322 | while (readl(dev->base + DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) { |
1ab52cf9 BS |
323 | if (timeout <= 0) { |
324 | dev_warn(dev->dev, "timeout waiting for bus ready\n"); | |
325 | return -ETIMEDOUT; | |
326 | } | |
327 | timeout--; | |
328 | mdelay(1); | |
329 | } | |
330 | ||
331 | return 0; | |
332 | } | |
333 | ||
81e798b7 SK |
334 | static void i2c_dw_xfer_init(struct dw_i2c_dev *dev) |
335 | { | |
336 | struct i2c_msg *msgs = dev->msgs; | |
337 | u32 ic_con; | |
338 | ||
339 | /* Disable the adapter */ | |
340 | writel(0, dev->base + DW_IC_ENABLE); | |
341 | ||
342 | /* set the slave (target) address */ | |
343 | writel(msgs[dev->msg_write_idx].addr, dev->base + DW_IC_TAR); | |
344 | ||
345 | /* if the slave address is ten bit address, enable 10BITADDR */ | |
346 | ic_con = readl(dev->base + DW_IC_CON); | |
347 | if (msgs[dev->msg_write_idx].flags & I2C_M_TEN) | |
348 | ic_con |= DW_IC_CON_10BITADDR_MASTER; | |
349 | else | |
350 | ic_con &= ~DW_IC_CON_10BITADDR_MASTER; | |
351 | writel(ic_con, dev->base + DW_IC_CON); | |
352 | ||
353 | /* Enable the adapter */ | |
354 | writel(1, dev->base + DW_IC_ENABLE); | |
201d6a70 SK |
355 | |
356 | /* Enable interrupts */ | |
357 | writel(DW_IC_INTR_DEFAULT_MASK, dev->base + DW_IC_INTR_MASK); | |
81e798b7 SK |
358 | } |
359 | ||
1ab52cf9 | 360 | /* |
201d6a70 SK |
361 | * Initiate (and continue) low level master read/write transaction. |
362 | * This function is only called from i2c_dw_isr, and pumping i2c_msg | |
363 | * messages into the tx buffer. Even if the size of i2c_msg data is | |
364 | * longer than the size of the tx buffer, it handles everything. | |
1ab52cf9 BS |
365 | */ |
366 | static void | |
e77cf232 | 367 | i2c_dw_xfer_msg(struct dw_i2c_dev *dev) |
1ab52cf9 | 368 | { |
1ab52cf9 | 369 | struct i2c_msg *msgs = dev->msgs; |
81e798b7 | 370 | u32 intr_mask; |
ae72222d | 371 | int tx_limit, rx_limit; |
ed5e1dd5 SK |
372 | u32 addr = msgs[dev->msg_write_idx].addr; |
373 | u32 buf_len = dev->tx_buf_len; | |
26ea15b1 | 374 | u8 *buf = dev->tx_buf;; |
1ab52cf9 | 375 | |
201d6a70 | 376 | intr_mask = DW_IC_INTR_DEFAULT_MASK; |
c70c5cd3 | 377 | |
6d2ea487 | 378 | for (; dev->msg_write_idx < dev->msgs_num; dev->msg_write_idx++) { |
1ab52cf9 BS |
379 | /* if target address has changed, we need to |
380 | * reprogram the target address in the i2c | |
381 | * adapter when we are done with this transfer | |
382 | */ | |
8f588e40 SK |
383 | if (msgs[dev->msg_write_idx].addr != addr) { |
384 | dev_err(dev->dev, | |
385 | "%s: invalid target address\n", __func__); | |
386 | dev->msg_err = -EINVAL; | |
387 | break; | |
388 | } | |
1ab52cf9 BS |
389 | |
390 | if (msgs[dev->msg_write_idx].len == 0) { | |
391 | dev_err(dev->dev, | |
392 | "%s: invalid message length\n", __func__); | |
393 | dev->msg_err = -EINVAL; | |
8f588e40 | 394 | break; |
1ab52cf9 BS |
395 | } |
396 | ||
397 | if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) { | |
398 | /* new i2c_msg */ | |
26ea15b1 | 399 | buf = msgs[dev->msg_write_idx].buf; |
1ab52cf9 BS |
400 | buf_len = msgs[dev->msg_write_idx].len; |
401 | } | |
402 | ||
ae72222d SK |
403 | tx_limit = dev->tx_fifo_depth - readl(dev->base + DW_IC_TXFLR); |
404 | rx_limit = dev->rx_fifo_depth - readl(dev->base + DW_IC_RXFLR); | |
405 | ||
1ab52cf9 BS |
406 | while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) { |
407 | if (msgs[dev->msg_write_idx].flags & I2C_M_RD) { | |
ed5e1dd5 | 408 | writel(0x100, dev->base + DW_IC_DATA_CMD); |
1ab52cf9 BS |
409 | rx_limit--; |
410 | } else | |
26ea15b1 | 411 | writel(*buf++, dev->base + DW_IC_DATA_CMD); |
1ab52cf9 BS |
412 | tx_limit--; buf_len--; |
413 | } | |
c70c5cd3 | 414 | |
26ea15b1 | 415 | dev->tx_buf = buf; |
c70c5cd3 SK |
416 | dev->tx_buf_len = buf_len; |
417 | ||
418 | if (buf_len > 0) { | |
419 | /* more bytes to be written */ | |
c70c5cd3 SK |
420 | dev->status |= STATUS_WRITE_IN_PROGRESS; |
421 | break; | |
69151e53 | 422 | } else |
c70c5cd3 | 423 | dev->status &= ~STATUS_WRITE_IN_PROGRESS; |
1ab52cf9 BS |
424 | } |
425 | ||
69151e53 SK |
426 | /* |
427 | * If i2c_msg index search is completed, we don't need TX_EMPTY | |
428 | * interrupt any more. | |
429 | */ | |
430 | if (dev->msg_write_idx == dev->msgs_num) | |
431 | intr_mask &= ~DW_IC_INTR_TX_EMPTY; | |
432 | ||
8f588e40 SK |
433 | if (dev->msg_err) |
434 | intr_mask = 0; | |
435 | ||
ed5e1dd5 | 436 | writel(intr_mask, dev->base + DW_IC_INTR_MASK); |
1ab52cf9 BS |
437 | } |
438 | ||
439 | static void | |
78839bd0 | 440 | i2c_dw_read(struct dw_i2c_dev *dev) |
1ab52cf9 | 441 | { |
1ab52cf9 | 442 | struct i2c_msg *msgs = dev->msgs; |
ae72222d | 443 | int rx_valid; |
1ab52cf9 | 444 | |
6d2ea487 | 445 | for (; dev->msg_read_idx < dev->msgs_num; dev->msg_read_idx++) { |
ed5e1dd5 | 446 | u32 len; |
1ab52cf9 BS |
447 | u8 *buf; |
448 | ||
449 | if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD)) | |
450 | continue; | |
451 | ||
1ab52cf9 BS |
452 | if (!(dev->status & STATUS_READ_IN_PROGRESS)) { |
453 | len = msgs[dev->msg_read_idx].len; | |
454 | buf = msgs[dev->msg_read_idx].buf; | |
455 | } else { | |
456 | len = dev->rx_buf_len; | |
457 | buf = dev->rx_buf; | |
458 | } | |
459 | ||
ae72222d SK |
460 | rx_valid = readl(dev->base + DW_IC_RXFLR); |
461 | ||
1ab52cf9 | 462 | for (; len > 0 && rx_valid > 0; len--, rx_valid--) |
ed5e1dd5 | 463 | *buf++ = readl(dev->base + DW_IC_DATA_CMD); |
1ab52cf9 BS |
464 | |
465 | if (len > 0) { | |
466 | dev->status |= STATUS_READ_IN_PROGRESS; | |
467 | dev->rx_buf_len = len; | |
468 | dev->rx_buf = buf; | |
469 | return; | |
470 | } else | |
471 | dev->status &= ~STATUS_READ_IN_PROGRESS; | |
472 | } | |
473 | } | |
474 | ||
475 | /* | |
476 | * Prepare controller for a transaction and call i2c_dw_xfer_msg | |
477 | */ | |
478 | static int | |
479 | i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) | |
480 | { | |
481 | struct dw_i2c_dev *dev = i2c_get_adapdata(adap); | |
482 | int ret; | |
483 | ||
484 | dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num); | |
485 | ||
486 | mutex_lock(&dev->lock); | |
487 | ||
488 | INIT_COMPLETION(dev->cmd_complete); | |
489 | dev->msgs = msgs; | |
490 | dev->msgs_num = num; | |
491 | dev->cmd_err = 0; | |
492 | dev->msg_write_idx = 0; | |
493 | dev->msg_read_idx = 0; | |
494 | dev->msg_err = 0; | |
495 | dev->status = STATUS_IDLE; | |
496 | ||
497 | ret = i2c_dw_wait_bus_not_busy(dev); | |
498 | if (ret < 0) | |
499 | goto done; | |
500 | ||
501 | /* start the transfers */ | |
81e798b7 | 502 | i2c_dw_xfer_init(dev); |
1ab52cf9 BS |
503 | |
504 | /* wait for tx to complete */ | |
505 | ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete, HZ); | |
506 | if (ret == 0) { | |
507 | dev_err(dev->dev, "controller timed out\n"); | |
508 | i2c_dw_init(dev); | |
509 | ret = -ETIMEDOUT; | |
510 | goto done; | |
511 | } else if (ret < 0) | |
512 | goto done; | |
513 | ||
514 | if (dev->msg_err) { | |
515 | ret = dev->msg_err; | |
516 | goto done; | |
517 | } | |
518 | ||
519 | /* no error */ | |
520 | if (likely(!dev->cmd_err)) { | |
07745399 | 521 | /* Disable the adapter */ |
ed5e1dd5 | 522 | writel(0, dev->base + DW_IC_ENABLE); |
1ab52cf9 BS |
523 | ret = num; |
524 | goto done; | |
525 | } | |
526 | ||
527 | /* We have an error */ | |
528 | if (dev->cmd_err == DW_IC_ERR_TX_ABRT) { | |
529 | unsigned long abort_source = dev->abort_source; | |
530 | int i; | |
531 | ||
532 | for_each_bit(i, &abort_source, ARRAY_SIZE(abort_sources)) { | |
533 | dev_err(dev->dev, "%s: %s\n", __func__, abort_sources[i]); | |
534 | } | |
535 | } | |
536 | ret = -EIO; | |
537 | ||
538 | done: | |
539 | mutex_unlock(&dev->lock); | |
540 | ||
541 | return ret; | |
542 | } | |
543 | ||
544 | static u32 i2c_dw_func(struct i2c_adapter *adap) | |
545 | { | |
52d7e430 SK |
546 | return I2C_FUNC_I2C | |
547 | I2C_FUNC_10BIT_ADDR | | |
548 | I2C_FUNC_SMBUS_BYTE | | |
549 | I2C_FUNC_SMBUS_BYTE_DATA | | |
550 | I2C_FUNC_SMBUS_WORD_DATA | | |
551 | I2C_FUNC_SMBUS_I2C_BLOCK; | |
1ab52cf9 BS |
552 | } |
553 | ||
e28000a3 SK |
554 | static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev) |
555 | { | |
556 | u32 stat; | |
557 | ||
558 | /* | |
559 | * The IC_INTR_STAT register just indicates "enabled" interrupts. | |
560 | * Ths unmasked raw version of interrupt status bits are available | |
561 | * in the IC_RAW_INTR_STAT register. | |
562 | * | |
563 | * That is, | |
564 | * stat = readl(IC_INTR_STAT); | |
565 | * equals to, | |
566 | * stat = readl(IC_RAW_INTR_STAT) & readl(IC_INTR_MASK); | |
567 | * | |
568 | * The raw version might be useful for debugging purposes. | |
569 | */ | |
570 | stat = readl(dev->base + DW_IC_INTR_STAT); | |
571 | ||
572 | /* | |
573 | * Do not use the IC_CLR_INTR register to clear interrupts, or | |
574 | * you'll miss some interrupts, triggered during the period from | |
575 | * readl(IC_INTR_STAT) to readl(IC_CLR_INTR). | |
576 | * | |
577 | * Instead, use the separately-prepared IC_CLR_* registers. | |
578 | */ | |
579 | if (stat & DW_IC_INTR_RX_UNDER) | |
580 | readl(dev->base + DW_IC_CLR_RX_UNDER); | |
581 | if (stat & DW_IC_INTR_RX_OVER) | |
582 | readl(dev->base + DW_IC_CLR_RX_OVER); | |
583 | if (stat & DW_IC_INTR_TX_OVER) | |
584 | readl(dev->base + DW_IC_CLR_TX_OVER); | |
585 | if (stat & DW_IC_INTR_RD_REQ) | |
586 | readl(dev->base + DW_IC_CLR_RD_REQ); | |
587 | if (stat & DW_IC_INTR_TX_ABRT) { | |
588 | /* | |
589 | * The IC_TX_ABRT_SOURCE register is cleared whenever | |
590 | * the IC_CLR_TX_ABRT is read. Preserve it beforehand. | |
591 | */ | |
592 | dev->abort_source = readl(dev->base + DW_IC_TX_ABRT_SOURCE); | |
593 | readl(dev->base + DW_IC_CLR_TX_ABRT); | |
594 | } | |
595 | if (stat & DW_IC_INTR_RX_DONE) | |
596 | readl(dev->base + DW_IC_CLR_RX_DONE); | |
597 | if (stat & DW_IC_INTR_ACTIVITY) | |
598 | readl(dev->base + DW_IC_CLR_ACTIVITY); | |
599 | if (stat & DW_IC_INTR_STOP_DET) | |
600 | readl(dev->base + DW_IC_CLR_STOP_DET); | |
601 | if (stat & DW_IC_INTR_START_DET) | |
602 | readl(dev->base + DW_IC_CLR_START_DET); | |
603 | if (stat & DW_IC_INTR_GEN_CALL) | |
604 | readl(dev->base + DW_IC_CLR_GEN_CALL); | |
605 | ||
606 | return stat; | |
607 | } | |
608 | ||
1ab52cf9 BS |
609 | /* |
610 | * Interrupt service routine. This gets called whenever an I2C interrupt | |
611 | * occurs. | |
612 | */ | |
613 | static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id) | |
614 | { | |
615 | struct dw_i2c_dev *dev = dev_id; | |
ed5e1dd5 | 616 | u32 stat; |
1ab52cf9 | 617 | |
e28000a3 | 618 | stat = i2c_dw_read_clear_intrbits(dev); |
1ab52cf9 | 619 | dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat); |
e28000a3 | 620 | |
1ab52cf9 | 621 | if (stat & DW_IC_INTR_TX_ABRT) { |
1ab52cf9 BS |
622 | dev->cmd_err |= DW_IC_ERR_TX_ABRT; |
623 | dev->status = STATUS_IDLE; | |
07745399 SK |
624 | } |
625 | ||
21a89d41 | 626 | if (stat & DW_IC_INTR_RX_FULL) |
07745399 | 627 | i2c_dw_read(dev); |
21a89d41 SK |
628 | |
629 | if (stat & DW_IC_INTR_TX_EMPTY) | |
07745399 | 630 | i2c_dw_xfer_msg(dev); |
07745399 SK |
631 | |
632 | /* | |
633 | * No need to modify or disable the interrupt mask here. | |
634 | * i2c_dw_xfer_msg() will take care of it according to | |
635 | * the current transmit status. | |
636 | */ | |
1ab52cf9 | 637 | |
8f588e40 | 638 | if ((stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET)) || dev->msg_err) |
1ab52cf9 BS |
639 | complete(&dev->cmd_complete); |
640 | ||
641 | return IRQ_HANDLED; | |
642 | } | |
643 | ||
644 | static struct i2c_algorithm i2c_dw_algo = { | |
645 | .master_xfer = i2c_dw_xfer, | |
646 | .functionality = i2c_dw_func, | |
647 | }; | |
648 | ||
649 | static int __devinit dw_i2c_probe(struct platform_device *pdev) | |
650 | { | |
651 | struct dw_i2c_dev *dev; | |
652 | struct i2c_adapter *adap; | |
91b52cae SK |
653 | struct resource *mem, *ioarea; |
654 | int irq, r; | |
1ab52cf9 BS |
655 | |
656 | /* NOTE: driver uses the static register mapping */ | |
657 | mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
658 | if (!mem) { | |
659 | dev_err(&pdev->dev, "no mem resource?\n"); | |
660 | return -EINVAL; | |
661 | } | |
662 | ||
91b52cae SK |
663 | irq = platform_get_irq(pdev, 0); |
664 | if (irq < 0) { | |
1ab52cf9 | 665 | dev_err(&pdev->dev, "no irq resource?\n"); |
91b52cae | 666 | return irq; /* -ENXIO */ |
1ab52cf9 BS |
667 | } |
668 | ||
669 | ioarea = request_mem_region(mem->start, resource_size(mem), | |
670 | pdev->name); | |
671 | if (!ioarea) { | |
672 | dev_err(&pdev->dev, "I2C region already claimed\n"); | |
673 | return -EBUSY; | |
674 | } | |
675 | ||
676 | dev = kzalloc(sizeof(struct dw_i2c_dev), GFP_KERNEL); | |
677 | if (!dev) { | |
678 | r = -ENOMEM; | |
679 | goto err_release_region; | |
680 | } | |
681 | ||
682 | init_completion(&dev->cmd_complete); | |
1ab52cf9 BS |
683 | mutex_init(&dev->lock); |
684 | dev->dev = get_device(&pdev->dev); | |
91b52cae | 685 | dev->irq = irq; |
1ab52cf9 BS |
686 | platform_set_drvdata(pdev, dev); |
687 | ||
688 | dev->clk = clk_get(&pdev->dev, NULL); | |
689 | if (IS_ERR(dev->clk)) { | |
690 | r = -ENODEV; | |
691 | goto err_free_mem; | |
692 | } | |
693 | clk_enable(dev->clk); | |
694 | ||
695 | dev->base = ioremap(mem->start, resource_size(mem)); | |
696 | if (dev->base == NULL) { | |
697 | dev_err(&pdev->dev, "failure mapping io resources\n"); | |
698 | r = -EBUSY; | |
699 | goto err_unuse_clocks; | |
700 | } | |
701 | { | |
702 | u32 param1 = readl(dev->base + DW_IC_COMP_PARAM_1); | |
703 | ||
704 | dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1; | |
705 | dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1; | |
706 | } | |
707 | i2c_dw_init(dev); | |
708 | ||
ed5e1dd5 | 709 | writel(0, dev->base + DW_IC_INTR_MASK); /* disable IRQ */ |
201d6a70 | 710 | r = request_irq(dev->irq, i2c_dw_isr, IRQF_DISABLED, pdev->name, dev); |
1ab52cf9 BS |
711 | if (r) { |
712 | dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq); | |
713 | goto err_iounmap; | |
714 | } | |
715 | ||
716 | adap = &dev->adapter; | |
717 | i2c_set_adapdata(adap, dev); | |
718 | adap->owner = THIS_MODULE; | |
719 | adap->class = I2C_CLASS_HWMON; | |
720 | strlcpy(adap->name, "Synopsys DesignWare I2C adapter", | |
721 | sizeof(adap->name)); | |
722 | adap->algo = &i2c_dw_algo; | |
723 | adap->dev.parent = &pdev->dev; | |
724 | ||
725 | adap->nr = pdev->id; | |
726 | r = i2c_add_numbered_adapter(adap); | |
727 | if (r) { | |
728 | dev_err(&pdev->dev, "failure adding adapter\n"); | |
729 | goto err_free_irq; | |
730 | } | |
731 | ||
732 | return 0; | |
733 | ||
734 | err_free_irq: | |
735 | free_irq(dev->irq, dev); | |
736 | err_iounmap: | |
737 | iounmap(dev->base); | |
738 | err_unuse_clocks: | |
739 | clk_disable(dev->clk); | |
740 | clk_put(dev->clk); | |
741 | dev->clk = NULL; | |
742 | err_free_mem: | |
743 | platform_set_drvdata(pdev, NULL); | |
744 | put_device(&pdev->dev); | |
745 | kfree(dev); | |
746 | err_release_region: | |
747 | release_mem_region(mem->start, resource_size(mem)); | |
748 | ||
749 | return r; | |
750 | } | |
751 | ||
752 | static int __devexit dw_i2c_remove(struct platform_device *pdev) | |
753 | { | |
754 | struct dw_i2c_dev *dev = platform_get_drvdata(pdev); | |
755 | struct resource *mem; | |
756 | ||
757 | platform_set_drvdata(pdev, NULL); | |
758 | i2c_del_adapter(&dev->adapter); | |
759 | put_device(&pdev->dev); | |
760 | ||
761 | clk_disable(dev->clk); | |
762 | clk_put(dev->clk); | |
763 | dev->clk = NULL; | |
764 | ||
ed5e1dd5 | 765 | writel(0, dev->base + DW_IC_ENABLE); |
1ab52cf9 BS |
766 | free_irq(dev->irq, dev); |
767 | kfree(dev); | |
768 | ||
769 | mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
770 | release_mem_region(mem->start, resource_size(mem)); | |
771 | return 0; | |
772 | } | |
773 | ||
774 | /* work with hotplug and coldplug */ | |
775 | MODULE_ALIAS("platform:i2c_designware"); | |
776 | ||
777 | static struct platform_driver dw_i2c_driver = { | |
778 | .remove = __devexit_p(dw_i2c_remove), | |
779 | .driver = { | |
780 | .name = "i2c_designware", | |
781 | .owner = THIS_MODULE, | |
782 | }, | |
783 | }; | |
784 | ||
785 | static int __init dw_i2c_init_driver(void) | |
786 | { | |
787 | return platform_driver_probe(&dw_i2c_driver, dw_i2c_probe); | |
788 | } | |
789 | module_init(dw_i2c_init_driver); | |
790 | ||
791 | static void __exit dw_i2c_exit_driver(void) | |
792 | { | |
793 | platform_driver_unregister(&dw_i2c_driver); | |
794 | } | |
795 | module_exit(dw_i2c_exit_driver); | |
796 | ||
797 | MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); | |
798 | MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); | |
799 | MODULE_LICENSE("GPL"); |