Commit | Line | Data |
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010d442c KS |
1 | /* |
2 | * TI OMAP I2C master mode driver | |
3 | * | |
4 | * Copyright (C) 2003 MontaVista Software, Inc. | |
5 | * Copyright (C) 2004 Texas Instruments. | |
6 | * | |
7 | * Updated to work with multiple I2C interfaces on 24xx by | |
8 | * Tony Lindgren <tony@atomide.com> and Imre Deak <imre.deak@nokia.com> | |
9 | * Copyright (C) 2005 Nokia Corporation | |
10 | * | |
96de0e25 | 11 | * Cleaned up by Juha Yrjölä <juha.yrjola@nokia.com> |
010d442c KS |
12 | * |
13 | * This program is free software; you can redistribute it and/or modify | |
14 | * it under the terms of the GNU General Public License as published by | |
15 | * the Free Software Foundation; either version 2 of the License, or | |
16 | * (at your option) any later version. | |
17 | * | |
18 | * This program is distributed in the hope that it will be useful, | |
19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
21 | * GNU General Public License for more details. | |
22 | * | |
23 | * You should have received a copy of the GNU General Public License | |
24 | * along with this program; if not, write to the Free Software | |
25 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
26 | */ | |
27 | ||
28 | #include <linux/module.h> | |
29 | #include <linux/delay.h> | |
30 | #include <linux/i2c.h> | |
31 | #include <linux/err.h> | |
32 | #include <linux/interrupt.h> | |
33 | #include <linux/completion.h> | |
34 | #include <linux/platform_device.h> | |
35 | #include <linux/clk.h> | |
36 | ||
37 | #include <asm/io.h> | |
38 | ||
39 | /* timeout waiting for the controller to respond */ | |
40 | #define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000)) | |
41 | ||
42 | #define OMAP_I2C_REV_REG 0x00 | |
43 | #define OMAP_I2C_IE_REG 0x04 | |
44 | #define OMAP_I2C_STAT_REG 0x08 | |
45 | #define OMAP_I2C_IV_REG 0x0c | |
46 | #define OMAP_I2C_SYSS_REG 0x10 | |
47 | #define OMAP_I2C_BUF_REG 0x14 | |
48 | #define OMAP_I2C_CNT_REG 0x18 | |
49 | #define OMAP_I2C_DATA_REG 0x1c | |
50 | #define OMAP_I2C_SYSC_REG 0x20 | |
51 | #define OMAP_I2C_CON_REG 0x24 | |
52 | #define OMAP_I2C_OA_REG 0x28 | |
53 | #define OMAP_I2C_SA_REG 0x2c | |
54 | #define OMAP_I2C_PSC_REG 0x30 | |
55 | #define OMAP_I2C_SCLL_REG 0x34 | |
56 | #define OMAP_I2C_SCLH_REG 0x38 | |
57 | #define OMAP_I2C_SYSTEST_REG 0x3c | |
58 | ||
59 | /* I2C Interrupt Enable Register (OMAP_I2C_IE): */ | |
60 | #define OMAP_I2C_IE_XRDY (1 << 4) /* TX data ready int enable */ | |
61 | #define OMAP_I2C_IE_RRDY (1 << 3) /* RX data ready int enable */ | |
62 | #define OMAP_I2C_IE_ARDY (1 << 2) /* Access ready int enable */ | |
63 | #define OMAP_I2C_IE_NACK (1 << 1) /* No ack interrupt enable */ | |
64 | #define OMAP_I2C_IE_AL (1 << 0) /* Arbitration lost int ena */ | |
65 | ||
66 | /* I2C Status Register (OMAP_I2C_STAT): */ | |
67 | #define OMAP_I2C_STAT_SBD (1 << 15) /* Single byte data */ | |
68 | #define OMAP_I2C_STAT_BB (1 << 12) /* Bus busy */ | |
69 | #define OMAP_I2C_STAT_ROVR (1 << 11) /* Receive overrun */ | |
70 | #define OMAP_I2C_STAT_XUDF (1 << 10) /* Transmit underflow */ | |
71 | #define OMAP_I2C_STAT_AAS (1 << 9) /* Address as slave */ | |
72 | #define OMAP_I2C_STAT_AD0 (1 << 8) /* Address zero */ | |
73 | #define OMAP_I2C_STAT_XRDY (1 << 4) /* Transmit data ready */ | |
74 | #define OMAP_I2C_STAT_RRDY (1 << 3) /* Receive data ready */ | |
75 | #define OMAP_I2C_STAT_ARDY (1 << 2) /* Register access ready */ | |
76 | #define OMAP_I2C_STAT_NACK (1 << 1) /* No ack interrupt enable */ | |
77 | #define OMAP_I2C_STAT_AL (1 << 0) /* Arbitration lost int ena */ | |
78 | ||
79 | /* I2C Buffer Configuration Register (OMAP_I2C_BUF): */ | |
80 | #define OMAP_I2C_BUF_RDMA_EN (1 << 15) /* RX DMA channel enable */ | |
81 | #define OMAP_I2C_BUF_XDMA_EN (1 << 7) /* TX DMA channel enable */ | |
82 | ||
83 | /* I2C Configuration Register (OMAP_I2C_CON): */ | |
84 | #define OMAP_I2C_CON_EN (1 << 15) /* I2C module enable */ | |
85 | #define OMAP_I2C_CON_BE (1 << 14) /* Big endian mode */ | |
86 | #define OMAP_I2C_CON_STB (1 << 11) /* Start byte mode (master) */ | |
87 | #define OMAP_I2C_CON_MST (1 << 10) /* Master/slave mode */ | |
88 | #define OMAP_I2C_CON_TRX (1 << 9) /* TX/RX mode (master only) */ | |
89 | #define OMAP_I2C_CON_XA (1 << 8) /* Expand address */ | |
90 | #define OMAP_I2C_CON_RM (1 << 2) /* Repeat mode (master only) */ | |
91 | #define OMAP_I2C_CON_STP (1 << 1) /* Stop cond (master only) */ | |
92 | #define OMAP_I2C_CON_STT (1 << 0) /* Start condition (master) */ | |
93 | ||
94 | /* I2C System Test Register (OMAP_I2C_SYSTEST): */ | |
95 | #ifdef DEBUG | |
96 | #define OMAP_I2C_SYSTEST_ST_EN (1 << 15) /* System test enable */ | |
97 | #define OMAP_I2C_SYSTEST_FREE (1 << 14) /* Free running mode */ | |
98 | #define OMAP_I2C_SYSTEST_TMODE_MASK (3 << 12) /* Test mode select */ | |
99 | #define OMAP_I2C_SYSTEST_TMODE_SHIFT (12) /* Test mode select */ | |
100 | #define OMAP_I2C_SYSTEST_SCL_I (1 << 3) /* SCL line sense in */ | |
101 | #define OMAP_I2C_SYSTEST_SCL_O (1 << 2) /* SCL line drive out */ | |
102 | #define OMAP_I2C_SYSTEST_SDA_I (1 << 1) /* SDA line sense in */ | |
103 | #define OMAP_I2C_SYSTEST_SDA_O (1 << 0) /* SDA line drive out */ | |
104 | #endif | |
105 | ||
106 | /* I2C System Status register (OMAP_I2C_SYSS): */ | |
107 | #define OMAP_I2C_SYSS_RDONE (1 << 0) /* Reset Done */ | |
108 | ||
109 | /* I2C System Configuration Register (OMAP_I2C_SYSC): */ | |
110 | #define OMAP_I2C_SYSC_SRST (1 << 1) /* Soft Reset */ | |
111 | ||
112 | /* REVISIT: Use platform_data instead of module parameters */ | |
113 | /* Fast Mode = 400 kHz, Standard = 100 kHz */ | |
114 | static int clock = 100; /* Default: 100 kHz */ | |
115 | module_param(clock, int, 0); | |
116 | MODULE_PARM_DESC(clock, "Set I2C clock in kHz: 400=fast mode (default == 100)"); | |
117 | ||
118 | struct omap_i2c_dev { | |
119 | struct device *dev; | |
120 | void __iomem *base; /* virtual */ | |
121 | int irq; | |
122 | struct clk *iclk; /* Interface clock */ | |
123 | struct clk *fclk; /* Functional clock */ | |
124 | struct completion cmd_complete; | |
125 | struct resource *ioarea; | |
126 | u16 cmd_err; | |
127 | u8 *buf; | |
128 | size_t buf_len; | |
129 | struct i2c_adapter adapter; | |
130 | unsigned rev1:1; | |
f08ac4e7 TL |
131 | unsigned idle:1; |
132 | u16 iestate; /* Saved interrupt register */ | |
010d442c KS |
133 | }; |
134 | ||
135 | static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev, | |
136 | int reg, u16 val) | |
137 | { | |
138 | __raw_writew(val, i2c_dev->base + reg); | |
139 | } | |
140 | ||
141 | static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg) | |
142 | { | |
143 | return __raw_readw(i2c_dev->base + reg); | |
144 | } | |
145 | ||
146 | static int omap_i2c_get_clocks(struct omap_i2c_dev *dev) | |
147 | { | |
148 | if (cpu_is_omap16xx() || cpu_is_omap24xx()) { | |
149 | dev->iclk = clk_get(dev->dev, "i2c_ick"); | |
150 | if (IS_ERR(dev->iclk)) { | |
151 | dev->iclk = NULL; | |
152 | return -ENODEV; | |
153 | } | |
154 | } | |
155 | ||
156 | dev->fclk = clk_get(dev->dev, "i2c_fck"); | |
157 | if (IS_ERR(dev->fclk)) { | |
158 | if (dev->iclk != NULL) { | |
159 | clk_put(dev->iclk); | |
160 | dev->iclk = NULL; | |
161 | } | |
162 | dev->fclk = NULL; | |
163 | return -ENODEV; | |
164 | } | |
165 | ||
166 | return 0; | |
167 | } | |
168 | ||
169 | static void omap_i2c_put_clocks(struct omap_i2c_dev *dev) | |
170 | { | |
171 | clk_put(dev->fclk); | |
172 | dev->fclk = NULL; | |
173 | if (dev->iclk != NULL) { | |
174 | clk_put(dev->iclk); | |
175 | dev->iclk = NULL; | |
176 | } | |
177 | } | |
178 | ||
f08ac4e7 | 179 | static void omap_i2c_unidle(struct omap_i2c_dev *dev) |
010d442c KS |
180 | { |
181 | if (dev->iclk != NULL) | |
182 | clk_enable(dev->iclk); | |
183 | clk_enable(dev->fclk); | |
0cbbcffd | 184 | dev->idle = 0; |
f08ac4e7 TL |
185 | if (dev->iestate) |
186 | omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate); | |
010d442c KS |
187 | } |
188 | ||
f08ac4e7 | 189 | static void omap_i2c_idle(struct omap_i2c_dev *dev) |
010d442c | 190 | { |
f08ac4e7 TL |
191 | u16 iv; |
192 | ||
f08ac4e7 TL |
193 | dev->iestate = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG); |
194 | omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, 0); | |
0cbbcffd | 195 | if (dev->rev1) { |
f08ac4e7 | 196 | iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG); /* Read clears */ |
0cbbcffd | 197 | } else { |
f08ac4e7 | 198 | omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, dev->iestate); |
0cbbcffd PW |
199 | |
200 | /* Flush posted write before the dev->idle store occurs */ | |
201 | omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG); | |
202 | } | |
203 | dev->idle = 1; | |
f08ac4e7 | 204 | clk_disable(dev->fclk); |
010d442c KS |
205 | if (dev->iclk != NULL) |
206 | clk_disable(dev->iclk); | |
010d442c KS |
207 | } |
208 | ||
209 | static int omap_i2c_init(struct omap_i2c_dev *dev) | |
210 | { | |
211 | u16 psc = 0; | |
212 | unsigned long fclk_rate = 12000000; | |
213 | unsigned long timeout; | |
214 | ||
215 | if (!dev->rev1) { | |
216 | omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, OMAP_I2C_SYSC_SRST); | |
217 | /* For some reason we need to set the EN bit before the | |
218 | * reset done bit gets set. */ | |
219 | timeout = jiffies + OMAP_I2C_TIMEOUT; | |
220 | omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); | |
221 | while (!(omap_i2c_read_reg(dev, OMAP_I2C_SYSS_REG) & | |
222 | OMAP_I2C_SYSS_RDONE)) { | |
223 | if (time_after(jiffies, timeout)) { | |
fce3ff03 | 224 | dev_warn(dev->dev, "timeout waiting " |
010d442c KS |
225 | "for controller reset\n"); |
226 | return -ETIMEDOUT; | |
227 | } | |
228 | msleep(1); | |
229 | } | |
230 | } | |
231 | omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0); | |
232 | ||
233 | if (cpu_class_is_omap1()) { | |
234 | struct clk *armxor_ck; | |
235 | ||
236 | armxor_ck = clk_get(NULL, "armxor_ck"); | |
237 | if (IS_ERR(armxor_ck)) | |
238 | dev_warn(dev->dev, "Could not get armxor_ck\n"); | |
239 | else { | |
240 | fclk_rate = clk_get_rate(armxor_ck); | |
241 | clk_put(armxor_ck); | |
242 | } | |
243 | /* TRM for 5912 says the I2C clock must be prescaled to be | |
244 | * between 7 - 12 MHz. The XOR input clock is typically | |
245 | * 12, 13 or 19.2 MHz. So we should have code that produces: | |
246 | * | |
247 | * XOR MHz Divider Prescaler | |
248 | * 12 1 0 | |
249 | * 13 2 1 | |
250 | * 19.2 2 1 | |
251 | */ | |
d7aef138 JD |
252 | if (fclk_rate > 12000000) |
253 | psc = fclk_rate / 12000000; | |
010d442c KS |
254 | } |
255 | ||
256 | /* Setup clock prescaler to obtain approx 12MHz I2C module clock: */ | |
257 | omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, psc); | |
258 | ||
259 | /* Program desired operating rate */ | |
260 | fclk_rate /= (psc + 1) * 1000; | |
261 | if (psc > 2) | |
262 | psc = 2; | |
263 | ||
264 | omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, | |
265 | fclk_rate / (clock * 2) - 7 + psc); | |
266 | omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, | |
267 | fclk_rate / (clock * 2) - 7 + psc); | |
268 | ||
269 | /* Take the I2C module out of reset: */ | |
270 | omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); | |
271 | ||
272 | /* Enable interrupts */ | |
273 | omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, | |
274 | (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY | | |
275 | OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK | | |
276 | OMAP_I2C_IE_AL)); | |
277 | return 0; | |
278 | } | |
279 | ||
280 | /* | |
281 | * Waiting on Bus Busy | |
282 | */ | |
283 | static int omap_i2c_wait_for_bb(struct omap_i2c_dev *dev) | |
284 | { | |
285 | unsigned long timeout; | |
286 | ||
287 | timeout = jiffies + OMAP_I2C_TIMEOUT; | |
288 | while (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) { | |
289 | if (time_after(jiffies, timeout)) { | |
290 | dev_warn(dev->dev, "timeout waiting for bus ready\n"); | |
291 | return -ETIMEDOUT; | |
292 | } | |
293 | msleep(1); | |
294 | } | |
295 | ||
296 | return 0; | |
297 | } | |
298 | ||
299 | /* | |
300 | * Low level master read/write transaction. | |
301 | */ | |
302 | static int omap_i2c_xfer_msg(struct i2c_adapter *adap, | |
303 | struct i2c_msg *msg, int stop) | |
304 | { | |
305 | struct omap_i2c_dev *dev = i2c_get_adapdata(adap); | |
306 | int r; | |
307 | u16 w; | |
308 | ||
309 | dev_dbg(dev->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n", | |
310 | msg->addr, msg->len, msg->flags, stop); | |
311 | ||
312 | if (msg->len == 0) | |
313 | return -EINVAL; | |
314 | ||
315 | omap_i2c_write_reg(dev, OMAP_I2C_SA_REG, msg->addr); | |
316 | ||
317 | /* REVISIT: Could the STB bit of I2C_CON be used with probing? */ | |
318 | dev->buf = msg->buf; | |
319 | dev->buf_len = msg->len; | |
320 | ||
321 | omap_i2c_write_reg(dev, OMAP_I2C_CNT_REG, dev->buf_len); | |
322 | ||
323 | init_completion(&dev->cmd_complete); | |
324 | dev->cmd_err = 0; | |
325 | ||
326 | w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT; | |
327 | if (msg->flags & I2C_M_TEN) | |
328 | w |= OMAP_I2C_CON_XA; | |
329 | if (!(msg->flags & I2C_M_RD)) | |
330 | w |= OMAP_I2C_CON_TRX; | |
331 | if (stop) | |
332 | w |= OMAP_I2C_CON_STP; | |
333 | omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w); | |
334 | ||
b7af349b JN |
335 | /* |
336 | * REVISIT: We should abort the transfer on signals, but the bus goes | |
337 | * into arbitration and we're currently unable to recover from it. | |
338 | */ | |
339 | r = wait_for_completion_timeout(&dev->cmd_complete, | |
340 | OMAP_I2C_TIMEOUT); | |
010d442c KS |
341 | dev->buf_len = 0; |
342 | if (r < 0) | |
343 | return r; | |
344 | if (r == 0) { | |
345 | dev_err(dev->dev, "controller timed out\n"); | |
346 | omap_i2c_init(dev); | |
347 | return -ETIMEDOUT; | |
348 | } | |
349 | ||
350 | if (likely(!dev->cmd_err)) | |
351 | return 0; | |
352 | ||
353 | /* We have an error */ | |
354 | if (dev->cmd_err & (OMAP_I2C_STAT_AL | OMAP_I2C_STAT_ROVR | | |
355 | OMAP_I2C_STAT_XUDF)) { | |
356 | omap_i2c_init(dev); | |
357 | return -EIO; | |
358 | } | |
359 | ||
360 | if (dev->cmd_err & OMAP_I2C_STAT_NACK) { | |
361 | if (msg->flags & I2C_M_IGNORE_NAK) | |
362 | return 0; | |
363 | if (stop) { | |
364 | w = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG); | |
365 | w |= OMAP_I2C_CON_STP; | |
366 | omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w); | |
367 | } | |
368 | return -EREMOTEIO; | |
369 | } | |
370 | return -EIO; | |
371 | } | |
372 | ||
373 | ||
374 | /* | |
375 | * Prepare controller for a transaction and call omap_i2c_xfer_msg | |
376 | * to do the work during IRQ processing. | |
377 | */ | |
378 | static int | |
379 | omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) | |
380 | { | |
381 | struct omap_i2c_dev *dev = i2c_get_adapdata(adap); | |
382 | int i; | |
383 | int r; | |
384 | ||
f08ac4e7 | 385 | omap_i2c_unidle(dev); |
010d442c | 386 | |
010d442c KS |
387 | if ((r = omap_i2c_wait_for_bb(dev)) < 0) |
388 | goto out; | |
389 | ||
390 | for (i = 0; i < num; i++) { | |
391 | r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1))); | |
392 | if (r != 0) | |
393 | break; | |
394 | } | |
395 | ||
396 | if (r == 0) | |
397 | r = num; | |
398 | out: | |
f08ac4e7 | 399 | omap_i2c_idle(dev); |
010d442c KS |
400 | return r; |
401 | } | |
402 | ||
403 | static u32 | |
404 | omap_i2c_func(struct i2c_adapter *adap) | |
405 | { | |
406 | return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK); | |
407 | } | |
408 | ||
409 | static inline void | |
410 | omap_i2c_complete_cmd(struct omap_i2c_dev *dev, u16 err) | |
411 | { | |
412 | dev->cmd_err |= err; | |
413 | complete(&dev->cmd_complete); | |
414 | } | |
415 | ||
416 | static inline void | |
417 | omap_i2c_ack_stat(struct omap_i2c_dev *dev, u16 stat) | |
418 | { | |
419 | omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat); | |
420 | } | |
421 | ||
422 | static irqreturn_t | |
7d12e780 | 423 | omap_i2c_rev1_isr(int this_irq, void *dev_id) |
010d442c KS |
424 | { |
425 | struct omap_i2c_dev *dev = dev_id; | |
426 | u16 iv, w; | |
427 | ||
f08ac4e7 TL |
428 | if (dev->idle) |
429 | return IRQ_NONE; | |
430 | ||
010d442c KS |
431 | iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG); |
432 | switch (iv) { | |
433 | case 0x00: /* None */ | |
434 | break; | |
435 | case 0x01: /* Arbitration lost */ | |
436 | dev_err(dev->dev, "Arbitration lost\n"); | |
437 | omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL); | |
438 | break; | |
439 | case 0x02: /* No acknowledgement */ | |
440 | omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK); | |
441 | omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP); | |
442 | break; | |
443 | case 0x03: /* Register access ready */ | |
444 | omap_i2c_complete_cmd(dev, 0); | |
445 | break; | |
446 | case 0x04: /* Receive data ready */ | |
447 | if (dev->buf_len) { | |
448 | w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG); | |
449 | *dev->buf++ = w; | |
450 | dev->buf_len--; | |
451 | if (dev->buf_len) { | |
452 | *dev->buf++ = w >> 8; | |
453 | dev->buf_len--; | |
454 | } | |
455 | } else | |
456 | dev_err(dev->dev, "RRDY IRQ while no data requested\n"); | |
457 | break; | |
458 | case 0x05: /* Transmit data ready */ | |
459 | if (dev->buf_len) { | |
460 | w = *dev->buf++; | |
461 | dev->buf_len--; | |
462 | if (dev->buf_len) { | |
463 | w |= *dev->buf++ << 8; | |
464 | dev->buf_len--; | |
465 | } | |
466 | omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w); | |
467 | } else | |
468 | dev_err(dev->dev, "XRDY IRQ while no data to send\n"); | |
469 | break; | |
470 | default: | |
471 | return IRQ_NONE; | |
472 | } | |
473 | ||
474 | return IRQ_HANDLED; | |
475 | } | |
476 | ||
477 | static irqreturn_t | |
7d12e780 | 478 | omap_i2c_isr(int this_irq, void *dev_id) |
010d442c KS |
479 | { |
480 | struct omap_i2c_dev *dev = dev_id; | |
481 | u16 bits; | |
482 | u16 stat, w; | |
483 | int count = 0; | |
484 | ||
f08ac4e7 TL |
485 | if (dev->idle) |
486 | return IRQ_NONE; | |
487 | ||
010d442c KS |
488 | bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG); |
489 | while ((stat = (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG))) & bits) { | |
490 | dev_dbg(dev->dev, "IRQ (ISR = 0x%04x)\n", stat); | |
491 | if (count++ == 100) { | |
492 | dev_warn(dev->dev, "Too much work in one IRQ\n"); | |
493 | break; | |
494 | } | |
495 | ||
496 | omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat); | |
497 | ||
498 | if (stat & OMAP_I2C_STAT_ARDY) { | |
499 | omap_i2c_complete_cmd(dev, 0); | |
500 | continue; | |
501 | } | |
502 | if (stat & OMAP_I2C_STAT_RRDY) { | |
503 | w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG); | |
504 | if (dev->buf_len) { | |
505 | *dev->buf++ = w; | |
506 | dev->buf_len--; | |
507 | if (dev->buf_len) { | |
508 | *dev->buf++ = w >> 8; | |
509 | dev->buf_len--; | |
510 | } | |
511 | } else | |
fce3ff03 | 512 | dev_err(dev->dev, "RRDY IRQ while no data " |
010d442c KS |
513 | "requested\n"); |
514 | omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RRDY); | |
515 | continue; | |
516 | } | |
517 | if (stat & OMAP_I2C_STAT_XRDY) { | |
518 | w = 0; | |
519 | if (dev->buf_len) { | |
520 | w = *dev->buf++; | |
521 | dev->buf_len--; | |
522 | if (dev->buf_len) { | |
523 | w |= *dev->buf++ << 8; | |
524 | dev->buf_len--; | |
525 | } | |
526 | } else | |
fce3ff03 | 527 | dev_err(dev->dev, "XRDY IRQ while no " |
010d442c KS |
528 | "data to send\n"); |
529 | omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w); | |
530 | omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XRDY); | |
531 | continue; | |
532 | } | |
533 | if (stat & OMAP_I2C_STAT_ROVR) { | |
534 | dev_err(dev->dev, "Receive overrun\n"); | |
535 | dev->cmd_err |= OMAP_I2C_STAT_ROVR; | |
536 | } | |
537 | if (stat & OMAP_I2C_STAT_XUDF) { | |
538 | dev_err(dev->dev, "Transmit overflow\n"); | |
539 | dev->cmd_err |= OMAP_I2C_STAT_XUDF; | |
540 | } | |
541 | if (stat & OMAP_I2C_STAT_NACK) { | |
542 | omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK); | |
543 | omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, | |
544 | OMAP_I2C_CON_STP); | |
545 | } | |
546 | if (stat & OMAP_I2C_STAT_AL) { | |
547 | dev_err(dev->dev, "Arbitration lost\n"); | |
548 | omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL); | |
549 | } | |
550 | } | |
551 | ||
552 | return count ? IRQ_HANDLED : IRQ_NONE; | |
553 | } | |
554 | ||
8f9082c5 | 555 | static const struct i2c_algorithm omap_i2c_algo = { |
010d442c KS |
556 | .master_xfer = omap_i2c_xfer, |
557 | .functionality = omap_i2c_func, | |
558 | }; | |
559 | ||
560 | static int | |
561 | omap_i2c_probe(struct platform_device *pdev) | |
562 | { | |
563 | struct omap_i2c_dev *dev; | |
564 | struct i2c_adapter *adap; | |
565 | struct resource *mem, *irq, *ioarea; | |
566 | int r; | |
567 | ||
568 | /* NOTE: driver uses the static register mapping */ | |
569 | mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
570 | if (!mem) { | |
571 | dev_err(&pdev->dev, "no mem resource?\n"); | |
572 | return -ENODEV; | |
573 | } | |
574 | irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); | |
575 | if (!irq) { | |
576 | dev_err(&pdev->dev, "no irq resource?\n"); | |
577 | return -ENODEV; | |
578 | } | |
579 | ||
580 | ioarea = request_mem_region(mem->start, (mem->end - mem->start) + 1, | |
581 | pdev->name); | |
582 | if (!ioarea) { | |
583 | dev_err(&pdev->dev, "I2C region already claimed\n"); | |
584 | return -EBUSY; | |
585 | } | |
586 | ||
587 | if (clock > 200) | |
588 | clock = 400; /* Fast mode */ | |
589 | else | |
590 | clock = 100; /* Standard mode */ | |
591 | ||
592 | dev = kzalloc(sizeof(struct omap_i2c_dev), GFP_KERNEL); | |
593 | if (!dev) { | |
594 | r = -ENOMEM; | |
595 | goto err_release_region; | |
596 | } | |
597 | ||
598 | dev->dev = &pdev->dev; | |
599 | dev->irq = irq->start; | |
55c381e4 RK |
600 | dev->base = ioremap(mem->start, mem->end - mem->start + 1); |
601 | if (!dev->base) { | |
602 | r = -ENOMEM; | |
603 | goto err_free_mem; | |
604 | } | |
605 | ||
010d442c KS |
606 | platform_set_drvdata(pdev, dev); |
607 | ||
608 | if ((r = omap_i2c_get_clocks(dev)) != 0) | |
55c381e4 | 609 | goto err_iounmap; |
010d442c | 610 | |
f08ac4e7 | 611 | omap_i2c_unidle(dev); |
010d442c KS |
612 | |
613 | if (cpu_is_omap15xx()) | |
614 | dev->rev1 = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) < 0x20; | |
615 | ||
616 | /* reset ASAP, clearing any IRQs */ | |
617 | omap_i2c_init(dev); | |
618 | ||
619 | r = request_irq(dev->irq, dev->rev1 ? omap_i2c_rev1_isr : omap_i2c_isr, | |
620 | 0, pdev->name, dev); | |
621 | ||
622 | if (r) { | |
623 | dev_err(dev->dev, "failure requesting irq %i\n", dev->irq); | |
624 | goto err_unuse_clocks; | |
625 | } | |
626 | r = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff; | |
627 | dev_info(dev->dev, "bus %d rev%d.%d at %d kHz\n", | |
628 | pdev->id, r >> 4, r & 0xf, clock); | |
629 | ||
630 | adap = &dev->adapter; | |
631 | i2c_set_adapdata(adap, dev); | |
632 | adap->owner = THIS_MODULE; | |
633 | adap->class = I2C_CLASS_HWMON; | |
634 | strncpy(adap->name, "OMAP I2C adapter", sizeof(adap->name)); | |
635 | adap->algo = &omap_i2c_algo; | |
636 | adap->dev.parent = &pdev->dev; | |
637 | ||
638 | /* i2c device drivers may be active on return from add_adapter() */ | |
7c175499 DB |
639 | adap->nr = pdev->id; |
640 | r = i2c_add_numbered_adapter(adap); | |
010d442c KS |
641 | if (r) { |
642 | dev_err(dev->dev, "failure adding adapter\n"); | |
643 | goto err_free_irq; | |
644 | } | |
645 | ||
f08ac4e7 | 646 | omap_i2c_idle(dev); |
010d442c KS |
647 | |
648 | return 0; | |
649 | ||
650 | err_free_irq: | |
651 | free_irq(dev->irq, dev); | |
652 | err_unuse_clocks: | |
3e39752d | 653 | omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0); |
f08ac4e7 | 654 | omap_i2c_idle(dev); |
010d442c | 655 | omap_i2c_put_clocks(dev); |
55c381e4 RK |
656 | err_iounmap: |
657 | iounmap(dev->base); | |
010d442c KS |
658 | err_free_mem: |
659 | platform_set_drvdata(pdev, NULL); | |
660 | kfree(dev); | |
661 | err_release_region: | |
010d442c KS |
662 | release_mem_region(mem->start, (mem->end - mem->start) + 1); |
663 | ||
664 | return r; | |
665 | } | |
666 | ||
667 | static int | |
668 | omap_i2c_remove(struct platform_device *pdev) | |
669 | { | |
670 | struct omap_i2c_dev *dev = platform_get_drvdata(pdev); | |
671 | struct resource *mem; | |
672 | ||
673 | platform_set_drvdata(pdev, NULL); | |
674 | ||
675 | free_irq(dev->irq, dev); | |
676 | i2c_del_adapter(&dev->adapter); | |
677 | omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0); | |
678 | omap_i2c_put_clocks(dev); | |
55c381e4 | 679 | iounmap(dev->base); |
010d442c KS |
680 | kfree(dev); |
681 | mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
682 | release_mem_region(mem->start, (mem->end - mem->start) + 1); | |
683 | return 0; | |
684 | } | |
685 | ||
686 | static struct platform_driver omap_i2c_driver = { | |
687 | .probe = omap_i2c_probe, | |
688 | .remove = omap_i2c_remove, | |
689 | .driver = { | |
690 | .name = "i2c_omap", | |
691 | .owner = THIS_MODULE, | |
692 | }, | |
693 | }; | |
694 | ||
695 | /* I2C may be needed to bring up other drivers */ | |
696 | static int __init | |
697 | omap_i2c_init_driver(void) | |
698 | { | |
699 | return platform_driver_register(&omap_i2c_driver); | |
700 | } | |
701 | subsys_initcall(omap_i2c_init_driver); | |
702 | ||
703 | static void __exit omap_i2c_exit_driver(void) | |
704 | { | |
705 | platform_driver_unregister(&omap_i2c_driver); | |
706 | } | |
707 | module_exit(omap_i2c_exit_driver); | |
708 | ||
709 | MODULE_AUTHOR("MontaVista Software, Inc. (and others)"); | |
710 | MODULE_DESCRIPTION("TI OMAP I2C bus adapter"); | |
711 | MODULE_LICENSE("GPL"); | |
add8eda7 | 712 | MODULE_ALIAS("platform:i2c_omap"); |