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6a62974b MY |
1 | /* |
2 | * Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@socionext.com> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | */ | |
14 | ||
15 | #include <linux/clk.h> | |
16 | #include <linux/i2c.h> | |
17 | #include <linux/interrupt.h> | |
18 | #include <linux/io.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/platform_device.h> | |
21 | ||
22 | #define UNIPHIER_FI2C_CR 0x00 /* control register */ | |
23 | #define UNIPHIER_FI2C_CR_MST BIT(3) /* master mode */ | |
24 | #define UNIPHIER_FI2C_CR_STA BIT(2) /* start condition */ | |
25 | #define UNIPHIER_FI2C_CR_STO BIT(1) /* stop condition */ | |
26 | #define UNIPHIER_FI2C_CR_NACK BIT(0) /* do not return ACK */ | |
27 | #define UNIPHIER_FI2C_DTTX 0x04 /* TX FIFO */ | |
28 | #define UNIPHIER_FI2C_DTTX_CMD BIT(8) /* send command (slave addr) */ | |
29 | #define UNIPHIER_FI2C_DTTX_RD BIT(0) /* read transaction */ | |
30 | #define UNIPHIER_FI2C_DTRX 0x04 /* RX FIFO */ | |
31 | #define UNIPHIER_FI2C_SLAD 0x0c /* slave address */ | |
32 | #define UNIPHIER_FI2C_CYC 0x10 /* clock cycle control */ | |
33 | #define UNIPHIER_FI2C_LCTL 0x14 /* clock low period control */ | |
34 | #define UNIPHIER_FI2C_SSUT 0x18 /* restart/stop setup time control */ | |
35 | #define UNIPHIER_FI2C_DSUT 0x1c /* data setup time control */ | |
36 | #define UNIPHIER_FI2C_INT 0x20 /* interrupt status */ | |
37 | #define UNIPHIER_FI2C_IE 0x24 /* interrupt enable */ | |
38 | #define UNIPHIER_FI2C_IC 0x28 /* interrupt clear */ | |
39 | #define UNIPHIER_FI2C_INT_TE BIT(9) /* TX FIFO empty */ | |
40 | #define UNIPHIER_FI2C_INT_RF BIT(8) /* RX FIFO full */ | |
41 | #define UNIPHIER_FI2C_INT_TC BIT(7) /* send complete (STOP) */ | |
42 | #define UNIPHIER_FI2C_INT_RC BIT(6) /* receive complete (STOP) */ | |
43 | #define UNIPHIER_FI2C_INT_TB BIT(5) /* sent specified bytes */ | |
44 | #define UNIPHIER_FI2C_INT_RB BIT(4) /* received specified bytes */ | |
45 | #define UNIPHIER_FI2C_INT_NA BIT(2) /* no ACK */ | |
46 | #define UNIPHIER_FI2C_INT_AL BIT(1) /* arbitration lost */ | |
47 | #define UNIPHIER_FI2C_SR 0x2c /* status register */ | |
48 | #define UNIPHIER_FI2C_SR_DB BIT(12) /* device busy */ | |
49 | #define UNIPHIER_FI2C_SR_STS BIT(11) /* stop condition detected */ | |
50 | #define UNIPHIER_FI2C_SR_BB BIT(8) /* bus busy */ | |
51 | #define UNIPHIER_FI2C_SR_RFF BIT(3) /* RX FIFO full */ | |
52 | #define UNIPHIER_FI2C_SR_RNE BIT(2) /* RX FIFO not empty */ | |
53 | #define UNIPHIER_FI2C_SR_TNF BIT(1) /* TX FIFO not full */ | |
54 | #define UNIPHIER_FI2C_SR_TFE BIT(0) /* TX FIFO empty */ | |
55 | #define UNIPHIER_FI2C_RST 0x34 /* reset control */ | |
56 | #define UNIPHIER_FI2C_RST_TBRST BIT(2) /* clear TX FIFO */ | |
57 | #define UNIPHIER_FI2C_RST_RBRST BIT(1) /* clear RX FIFO */ | |
58 | #define UNIPHIER_FI2C_RST_RST BIT(0) /* forcible bus reset */ | |
59 | #define UNIPHIER_FI2C_BM 0x38 /* bus monitor */ | |
60 | #define UNIPHIER_FI2C_BM_SDAO BIT(3) /* output for SDA line */ | |
61 | #define UNIPHIER_FI2C_BM_SDAS BIT(2) /* readback of SDA line */ | |
62 | #define UNIPHIER_FI2C_BM_SCLO BIT(1) /* output for SCL line */ | |
63 | #define UNIPHIER_FI2C_BM_SCLS BIT(0) /* readback of SCL line */ | |
64 | #define UNIPHIER_FI2C_NOISE 0x3c /* noise filter control */ | |
65 | #define UNIPHIER_FI2C_TBC 0x40 /* TX byte count setting */ | |
66 | #define UNIPHIER_FI2C_RBC 0x44 /* RX byte count setting */ | |
67 | #define UNIPHIER_FI2C_TBCM 0x48 /* TX byte count monitor */ | |
68 | #define UNIPHIER_FI2C_RBCM 0x4c /* RX byte count monitor */ | |
69 | #define UNIPHIER_FI2C_BRST 0x50 /* bus reset */ | |
70 | #define UNIPHIER_FI2C_BRST_FOEN BIT(1) /* normal operation */ | |
71 | #define UNIPHIER_FI2C_BRST_RSCL BIT(0) /* release SCL */ | |
72 | ||
73 | #define UNIPHIER_FI2C_INT_FAULTS \ | |
74 | (UNIPHIER_FI2C_INT_NA | UNIPHIER_FI2C_INT_AL) | |
75 | #define UNIPHIER_FI2C_INT_STOP \ | |
76 | (UNIPHIER_FI2C_INT_TC | UNIPHIER_FI2C_INT_RC) | |
77 | ||
78 | #define UNIPHIER_FI2C_RD BIT(0) | |
79 | #define UNIPHIER_FI2C_STOP BIT(1) | |
80 | #define UNIPHIER_FI2C_MANUAL_NACK BIT(2) | |
81 | #define UNIPHIER_FI2C_BYTE_WISE BIT(3) | |
82 | #define UNIPHIER_FI2C_DEFER_STOP_COMP BIT(4) | |
83 | ||
84 | #define UNIPHIER_FI2C_DEFAULT_SPEED 100000 | |
85 | #define UNIPHIER_FI2C_MAX_SPEED 400000 | |
86 | #define UNIPHIER_FI2C_FIFO_SIZE 8 | |
87 | ||
88 | struct uniphier_fi2c_priv { | |
89 | struct completion comp; | |
90 | struct i2c_adapter adap; | |
91 | void __iomem *membase; | |
92 | struct clk *clk; | |
93 | unsigned int len; | |
94 | u8 *buf; | |
95 | u32 enabled_irqs; | |
96 | int error; | |
97 | unsigned int flags; | |
98 | unsigned int busy_cnt; | |
99 | }; | |
100 | ||
101 | static void uniphier_fi2c_fill_txfifo(struct uniphier_fi2c_priv *priv, | |
102 | bool first) | |
103 | { | |
104 | int fifo_space = UNIPHIER_FI2C_FIFO_SIZE; | |
105 | ||
106 | /* | |
107 | * TX-FIFO stores slave address in it for the first access. | |
108 | * Decrement the counter. | |
109 | */ | |
110 | if (first) | |
111 | fifo_space--; | |
112 | ||
113 | while (priv->len) { | |
114 | if (fifo_space-- <= 0) | |
115 | break; | |
116 | ||
117 | dev_dbg(&priv->adap.dev, "write data: %02x\n", *priv->buf); | |
118 | writel(*priv->buf++, priv->membase + UNIPHIER_FI2C_DTTX); | |
119 | priv->len--; | |
120 | } | |
121 | } | |
122 | ||
123 | static void uniphier_fi2c_drain_rxfifo(struct uniphier_fi2c_priv *priv) | |
124 | { | |
125 | int fifo_left = priv->flags & UNIPHIER_FI2C_BYTE_WISE ? | |
126 | 1 : UNIPHIER_FI2C_FIFO_SIZE; | |
127 | ||
128 | while (priv->len) { | |
129 | if (fifo_left-- <= 0) | |
130 | break; | |
131 | ||
132 | *priv->buf++ = readl(priv->membase + UNIPHIER_FI2C_DTRX); | |
133 | dev_dbg(&priv->adap.dev, "read data: %02x\n", priv->buf[-1]); | |
134 | priv->len--; | |
135 | } | |
136 | } | |
137 | ||
138 | static void uniphier_fi2c_set_irqs(struct uniphier_fi2c_priv *priv) | |
139 | { | |
140 | writel(priv->enabled_irqs, priv->membase + UNIPHIER_FI2C_IE); | |
141 | } | |
142 | ||
143 | static void uniphier_fi2c_clear_irqs(struct uniphier_fi2c_priv *priv) | |
144 | { | |
145 | writel(-1, priv->membase + UNIPHIER_FI2C_IC); | |
146 | } | |
147 | ||
148 | static void uniphier_fi2c_stop(struct uniphier_fi2c_priv *priv) | |
149 | { | |
150 | dev_dbg(&priv->adap.dev, "stop condition\n"); | |
151 | ||
152 | priv->enabled_irqs |= UNIPHIER_FI2C_INT_STOP; | |
153 | uniphier_fi2c_set_irqs(priv); | |
154 | writel(UNIPHIER_FI2C_CR_MST | UNIPHIER_FI2C_CR_STO, | |
155 | priv->membase + UNIPHIER_FI2C_CR); | |
156 | } | |
157 | ||
158 | static irqreturn_t uniphier_fi2c_interrupt(int irq, void *dev_id) | |
159 | { | |
160 | struct uniphier_fi2c_priv *priv = dev_id; | |
161 | u32 irq_status; | |
162 | ||
163 | irq_status = readl(priv->membase + UNIPHIER_FI2C_INT); | |
164 | ||
165 | dev_dbg(&priv->adap.dev, | |
166 | "interrupt: enabled_irqs=%04x, irq_status=%04x\n", | |
167 | priv->enabled_irqs, irq_status); | |
168 | ||
169 | if (irq_status & UNIPHIER_FI2C_INT_STOP) | |
170 | goto complete; | |
171 | ||
172 | if (unlikely(irq_status & UNIPHIER_FI2C_INT_AL)) { | |
173 | dev_dbg(&priv->adap.dev, "arbitration lost\n"); | |
174 | priv->error = -EAGAIN; | |
175 | goto complete; | |
176 | } | |
177 | ||
178 | if (unlikely(irq_status & UNIPHIER_FI2C_INT_NA)) { | |
179 | dev_dbg(&priv->adap.dev, "could not get ACK\n"); | |
180 | priv->error = -ENXIO; | |
181 | if (priv->flags & UNIPHIER_FI2C_RD) { | |
182 | /* | |
183 | * work around a hardware bug: | |
184 | * The receive-completed interrupt is never set even if | |
185 | * STOP condition is detected after the address phase | |
186 | * of read transaction fails to get ACK. | |
187 | * To avoid time-out error, we issue STOP here, | |
188 | * but do not wait for its completion. | |
189 | * It should be checked after exiting this handler. | |
190 | */ | |
191 | uniphier_fi2c_stop(priv); | |
192 | priv->flags |= UNIPHIER_FI2C_DEFER_STOP_COMP; | |
193 | goto complete; | |
194 | } | |
195 | goto stop; | |
196 | } | |
197 | ||
198 | if (irq_status & UNIPHIER_FI2C_INT_TE) { | |
199 | if (!priv->len) | |
200 | goto data_done; | |
201 | ||
202 | uniphier_fi2c_fill_txfifo(priv, false); | |
203 | goto handled; | |
204 | } | |
205 | ||
206 | if (irq_status & (UNIPHIER_FI2C_INT_RF | UNIPHIER_FI2C_INT_RB)) { | |
207 | uniphier_fi2c_drain_rxfifo(priv); | |
208 | if (!priv->len) | |
209 | goto data_done; | |
210 | ||
211 | if (unlikely(priv->flags & UNIPHIER_FI2C_MANUAL_NACK)) { | |
212 | if (priv->len <= UNIPHIER_FI2C_FIFO_SIZE && | |
213 | !(priv->flags & UNIPHIER_FI2C_BYTE_WISE)) { | |
214 | dev_dbg(&priv->adap.dev, | |
215 | "enable read byte count IRQ\n"); | |
216 | priv->enabled_irqs |= UNIPHIER_FI2C_INT_RB; | |
217 | uniphier_fi2c_set_irqs(priv); | |
218 | priv->flags |= UNIPHIER_FI2C_BYTE_WISE; | |
219 | } | |
220 | if (priv->len <= 1) { | |
221 | dev_dbg(&priv->adap.dev, "set NACK\n"); | |
222 | writel(UNIPHIER_FI2C_CR_MST | | |
223 | UNIPHIER_FI2C_CR_NACK, | |
224 | priv->membase + UNIPHIER_FI2C_CR); | |
225 | } | |
226 | } | |
227 | ||
228 | goto handled; | |
229 | } | |
230 | ||
231 | return IRQ_NONE; | |
232 | ||
233 | data_done: | |
234 | if (priv->flags & UNIPHIER_FI2C_STOP) { | |
235 | stop: | |
236 | uniphier_fi2c_stop(priv); | |
237 | } else { | |
238 | complete: | |
239 | priv->enabled_irqs = 0; | |
240 | uniphier_fi2c_set_irqs(priv); | |
241 | complete(&priv->comp); | |
242 | } | |
243 | ||
244 | handled: | |
245 | uniphier_fi2c_clear_irqs(priv); | |
246 | ||
247 | return IRQ_HANDLED; | |
248 | } | |
249 | ||
250 | static void uniphier_fi2c_tx_init(struct uniphier_fi2c_priv *priv, u16 addr) | |
251 | { | |
252 | priv->enabled_irqs |= UNIPHIER_FI2C_INT_TE; | |
253 | /* do not use TX byte counter */ | |
254 | writel(0, priv->membase + UNIPHIER_FI2C_TBC); | |
255 | /* set slave address */ | |
256 | writel(UNIPHIER_FI2C_DTTX_CMD | addr << 1, | |
257 | priv->membase + UNIPHIER_FI2C_DTTX); | |
258 | /* first chunk of data */ | |
259 | uniphier_fi2c_fill_txfifo(priv, true); | |
260 | } | |
261 | ||
262 | static void uniphier_fi2c_rx_init(struct uniphier_fi2c_priv *priv, u16 addr) | |
263 | { | |
264 | priv->flags |= UNIPHIER_FI2C_RD; | |
265 | ||
266 | if (likely(priv->len < 256)) { | |
267 | /* | |
268 | * If possible, use RX byte counter. | |
269 | * It can automatically handle NACK for the last byte. | |
270 | */ | |
271 | writel(priv->len, priv->membase + UNIPHIER_FI2C_RBC); | |
272 | priv->enabled_irqs |= UNIPHIER_FI2C_INT_RF | | |
273 | UNIPHIER_FI2C_INT_RB; | |
274 | } else { | |
275 | /* | |
276 | * The byte counter can not count over 256. In this case, | |
277 | * do not use it at all. Drain data when FIFO gets full, | |
278 | * but treat the last portion as a special case. | |
279 | */ | |
280 | writel(0, priv->membase + UNIPHIER_FI2C_RBC); | |
281 | priv->flags |= UNIPHIER_FI2C_MANUAL_NACK; | |
282 | priv->enabled_irqs |= UNIPHIER_FI2C_INT_RF; | |
283 | } | |
284 | ||
285 | /* set slave address with RD bit */ | |
286 | writel(UNIPHIER_FI2C_DTTX_CMD | UNIPHIER_FI2C_DTTX_RD | addr << 1, | |
287 | priv->membase + UNIPHIER_FI2C_DTTX); | |
288 | } | |
289 | ||
290 | static void uniphier_fi2c_reset(struct uniphier_fi2c_priv *priv) | |
291 | { | |
292 | writel(UNIPHIER_FI2C_RST_RST, priv->membase + UNIPHIER_FI2C_RST); | |
293 | } | |
294 | ||
295 | static void uniphier_fi2c_prepare_operation(struct uniphier_fi2c_priv *priv) | |
296 | { | |
297 | writel(UNIPHIER_FI2C_BRST_FOEN | UNIPHIER_FI2C_BRST_RSCL, | |
298 | priv->membase + UNIPHIER_FI2C_BRST); | |
299 | } | |
300 | ||
301 | static void uniphier_fi2c_recover(struct uniphier_fi2c_priv *priv) | |
302 | { | |
303 | uniphier_fi2c_reset(priv); | |
304 | i2c_recover_bus(&priv->adap); | |
305 | } | |
306 | ||
307 | static int uniphier_fi2c_master_xfer_one(struct i2c_adapter *adap, | |
308 | struct i2c_msg *msg, bool stop) | |
309 | { | |
310 | struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap); | |
311 | bool is_read = msg->flags & I2C_M_RD; | |
312 | unsigned long time_left; | |
313 | ||
314 | dev_dbg(&adap->dev, "%s: addr=0x%02x, len=%d, stop=%d\n", | |
315 | is_read ? "receive" : "transmit", msg->addr, msg->len, stop); | |
316 | ||
317 | priv->len = msg->len; | |
318 | priv->buf = msg->buf; | |
319 | priv->enabled_irqs = UNIPHIER_FI2C_INT_FAULTS; | |
320 | priv->error = 0; | |
321 | priv->flags = 0; | |
322 | ||
323 | if (stop) | |
324 | priv->flags |= UNIPHIER_FI2C_STOP; | |
325 | ||
326 | reinit_completion(&priv->comp); | |
327 | uniphier_fi2c_clear_irqs(priv); | |
328 | writel(UNIPHIER_FI2C_RST_TBRST | UNIPHIER_FI2C_RST_RBRST, | |
329 | priv->membase + UNIPHIER_FI2C_RST); /* reset TX/RX FIFO */ | |
330 | ||
331 | if (is_read) | |
332 | uniphier_fi2c_rx_init(priv, msg->addr); | |
333 | else | |
334 | uniphier_fi2c_tx_init(priv, msg->addr); | |
335 | ||
336 | uniphier_fi2c_set_irqs(priv); | |
337 | ||
338 | dev_dbg(&adap->dev, "start condition\n"); | |
339 | writel(UNIPHIER_FI2C_CR_MST | UNIPHIER_FI2C_CR_STA, | |
340 | priv->membase + UNIPHIER_FI2C_CR); | |
341 | ||
342 | time_left = wait_for_completion_timeout(&priv->comp, adap->timeout); | |
343 | if (!time_left) { | |
344 | dev_err(&adap->dev, "transaction timeout.\n"); | |
345 | uniphier_fi2c_recover(priv); | |
346 | return -ETIMEDOUT; | |
347 | } | |
348 | dev_dbg(&adap->dev, "complete\n"); | |
349 | ||
350 | if (unlikely(priv->flags & UNIPHIER_FI2C_DEFER_STOP_COMP)) { | |
351 | u32 status = readl(priv->membase + UNIPHIER_FI2C_SR); | |
352 | ||
353 | if (!(status & UNIPHIER_FI2C_SR_STS) || | |
354 | status & UNIPHIER_FI2C_SR_BB) { | |
355 | dev_err(&adap->dev, | |
356 | "stop condition was not completed.\n"); | |
357 | uniphier_fi2c_recover(priv); | |
358 | return -EBUSY; | |
359 | } | |
360 | } | |
361 | ||
362 | return priv->error; | |
363 | } | |
364 | ||
365 | static int uniphier_fi2c_check_bus_busy(struct i2c_adapter *adap) | |
366 | { | |
367 | struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap); | |
368 | ||
369 | if (readl(priv->membase + UNIPHIER_FI2C_SR) & UNIPHIER_FI2C_SR_DB) { | |
370 | if (priv->busy_cnt++ > 3) { | |
371 | /* | |
372 | * If bus busy continues too long, it is probably | |
373 | * in a wrong state. Try bus recovery. | |
374 | */ | |
375 | uniphier_fi2c_recover(priv); | |
376 | priv->busy_cnt = 0; | |
377 | } | |
378 | ||
379 | return -EAGAIN; | |
380 | } | |
381 | ||
382 | priv->busy_cnt = 0; | |
383 | return 0; | |
384 | } | |
385 | ||
386 | static int uniphier_fi2c_master_xfer(struct i2c_adapter *adap, | |
387 | struct i2c_msg *msgs, int num) | |
388 | { | |
389 | struct i2c_msg *msg, *emsg = msgs + num; | |
390 | int ret; | |
391 | ||
392 | ret = uniphier_fi2c_check_bus_busy(adap); | |
393 | if (ret) | |
394 | return ret; | |
395 | ||
396 | for (msg = msgs; msg < emsg; msg++) { | |
397 | /* If next message is read, skip the stop condition */ | |
398 | bool stop = !(msg + 1 < emsg && msg[1].flags & I2C_M_RD); | |
399 | /* but, force it if I2C_M_STOP is set */ | |
400 | if (msg->flags & I2C_M_STOP) | |
401 | stop = true; | |
402 | ||
403 | ret = uniphier_fi2c_master_xfer_one(adap, msg, stop); | |
404 | if (ret) | |
405 | return ret; | |
406 | } | |
407 | ||
408 | return num; | |
409 | } | |
410 | ||
411 | static u32 uniphier_fi2c_functionality(struct i2c_adapter *adap) | |
412 | { | |
413 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; | |
414 | } | |
415 | ||
416 | static const struct i2c_algorithm uniphier_fi2c_algo = { | |
417 | .master_xfer = uniphier_fi2c_master_xfer, | |
418 | .functionality = uniphier_fi2c_functionality, | |
419 | }; | |
420 | ||
421 | static int uniphier_fi2c_get_scl(struct i2c_adapter *adap) | |
422 | { | |
423 | struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap); | |
424 | ||
425 | return !!(readl(priv->membase + UNIPHIER_FI2C_BM) & | |
426 | UNIPHIER_FI2C_BM_SCLS); | |
427 | } | |
428 | ||
429 | static void uniphier_fi2c_set_scl(struct i2c_adapter *adap, int val) | |
430 | { | |
431 | struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap); | |
432 | ||
433 | writel(val ? UNIPHIER_FI2C_BRST_RSCL : 0, | |
434 | priv->membase + UNIPHIER_FI2C_BRST); | |
435 | } | |
436 | ||
437 | static int uniphier_fi2c_get_sda(struct i2c_adapter *adap) | |
438 | { | |
439 | struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap); | |
440 | ||
441 | return !!(readl(priv->membase + UNIPHIER_FI2C_BM) & | |
442 | UNIPHIER_FI2C_BM_SDAS); | |
443 | } | |
444 | ||
445 | static void uniphier_fi2c_unprepare_recovery(struct i2c_adapter *adap) | |
446 | { | |
447 | uniphier_fi2c_prepare_operation(i2c_get_adapdata(adap)); | |
448 | } | |
449 | ||
450 | static struct i2c_bus_recovery_info uniphier_fi2c_bus_recovery_info = { | |
451 | .recover_bus = i2c_generic_scl_recovery, | |
452 | .get_scl = uniphier_fi2c_get_scl, | |
453 | .set_scl = uniphier_fi2c_set_scl, | |
454 | .get_sda = uniphier_fi2c_get_sda, | |
455 | .unprepare_recovery = uniphier_fi2c_unprepare_recovery, | |
456 | }; | |
457 | ||
458 | static int uniphier_fi2c_clk_init(struct device *dev, | |
459 | struct uniphier_fi2c_priv *priv) | |
460 | { | |
461 | struct device_node *np = dev->of_node; | |
462 | unsigned long clk_rate; | |
463 | u32 bus_speed, clk_count; | |
464 | int ret; | |
465 | ||
466 | if (of_property_read_u32(np, "clock-frequency", &bus_speed)) | |
467 | bus_speed = UNIPHIER_FI2C_DEFAULT_SPEED; | |
468 | ||
51549c08 | 469 | if (!bus_speed) { |
bca71ba0 | 470 | dev_err(dev, "clock-frequency should not be zero\n"); |
51549c08 MY |
471 | return -EINVAL; |
472 | } | |
473 | ||
6a62974b MY |
474 | if (bus_speed > UNIPHIER_FI2C_MAX_SPEED) |
475 | bus_speed = UNIPHIER_FI2C_MAX_SPEED; | |
476 | ||
477 | /* Get input clk rate through clk driver */ | |
478 | priv->clk = devm_clk_get(dev, NULL); | |
479 | if (IS_ERR(priv->clk)) { | |
480 | dev_err(dev, "failed to get clock\n"); | |
481 | return PTR_ERR(priv->clk); | |
482 | } | |
483 | ||
484 | ret = clk_prepare_enable(priv->clk); | |
485 | if (ret) | |
486 | return ret; | |
487 | ||
488 | clk_rate = clk_get_rate(priv->clk); | |
ac9b91f3 MY |
489 | if (!clk_rate) { |
490 | dev_err(dev, "input clock rate should not be zero\n"); | |
491 | return -EINVAL; | |
492 | } | |
6a62974b MY |
493 | |
494 | uniphier_fi2c_reset(priv); | |
495 | ||
496 | clk_count = clk_rate / bus_speed; | |
497 | ||
498 | writel(clk_count, priv->membase + UNIPHIER_FI2C_CYC); | |
499 | writel(clk_count / 2, priv->membase + UNIPHIER_FI2C_LCTL); | |
500 | writel(clk_count / 2, priv->membase + UNIPHIER_FI2C_SSUT); | |
501 | writel(clk_count / 16, priv->membase + UNIPHIER_FI2C_DSUT); | |
502 | ||
503 | uniphier_fi2c_prepare_operation(priv); | |
504 | ||
505 | return 0; | |
506 | } | |
507 | ||
508 | static int uniphier_fi2c_probe(struct platform_device *pdev) | |
509 | { | |
510 | struct device *dev = &pdev->dev; | |
511 | struct uniphier_fi2c_priv *priv; | |
512 | struct resource *regs; | |
513 | int irq; | |
514 | int ret; | |
515 | ||
516 | priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); | |
517 | if (!priv) | |
518 | return -ENOMEM; | |
519 | ||
520 | regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
521 | priv->membase = devm_ioremap_resource(dev, regs); | |
522 | if (IS_ERR(priv->membase)) | |
523 | return PTR_ERR(priv->membase); | |
524 | ||
525 | irq = platform_get_irq(pdev, 0); | |
526 | if (irq < 0) { | |
527 | dev_err(dev, "failed to get IRQ number"); | |
528 | return irq; | |
529 | } | |
530 | ||
531 | init_completion(&priv->comp); | |
532 | priv->adap.owner = THIS_MODULE; | |
533 | priv->adap.algo = &uniphier_fi2c_algo; | |
534 | priv->adap.dev.parent = dev; | |
535 | priv->adap.dev.of_node = dev->of_node; | |
536 | strlcpy(priv->adap.name, "UniPhier FI2C", sizeof(priv->adap.name)); | |
537 | priv->adap.bus_recovery_info = &uniphier_fi2c_bus_recovery_info; | |
538 | i2c_set_adapdata(&priv->adap, priv); | |
539 | platform_set_drvdata(pdev, priv); | |
540 | ||
541 | ret = uniphier_fi2c_clk_init(dev, priv); | |
542 | if (ret) | |
ac9b91f3 | 543 | goto err; |
6a62974b MY |
544 | |
545 | ret = devm_request_irq(dev, irq, uniphier_fi2c_interrupt, 0, | |
546 | pdev->name, priv); | |
547 | if (ret) { | |
548 | dev_err(dev, "failed to request irq %d\n", irq); | |
549 | goto err; | |
550 | } | |
551 | ||
552 | ret = i2c_add_adapter(&priv->adap); | |
553 | if (ret) { | |
554 | dev_err(dev, "failed to add I2C adapter\n"); | |
555 | goto err; | |
556 | } | |
557 | ||
558 | err: | |
559 | if (ret) | |
560 | clk_disable_unprepare(priv->clk); | |
561 | ||
562 | return ret; | |
563 | } | |
564 | ||
565 | static int uniphier_fi2c_remove(struct platform_device *pdev) | |
566 | { | |
567 | struct uniphier_fi2c_priv *priv = platform_get_drvdata(pdev); | |
568 | ||
569 | i2c_del_adapter(&priv->adap); | |
570 | clk_disable_unprepare(priv->clk); | |
571 | ||
572 | return 0; | |
573 | } | |
574 | ||
575 | static const struct of_device_id uniphier_fi2c_match[] = { | |
576 | { .compatible = "socionext,uniphier-fi2c" }, | |
577 | { /* sentinel */ } | |
578 | }; | |
579 | MODULE_DEVICE_TABLE(of, uniphier_fi2c_match); | |
580 | ||
581 | static struct platform_driver uniphier_fi2c_drv = { | |
582 | .probe = uniphier_fi2c_probe, | |
583 | .remove = uniphier_fi2c_remove, | |
584 | .driver = { | |
585 | .name = "uniphier-fi2c", | |
586 | .of_match_table = uniphier_fi2c_match, | |
587 | }, | |
588 | }; | |
589 | module_platform_driver(uniphier_fi2c_drv); | |
590 | ||
591 | MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>"); | |
592 | MODULE_DESCRIPTION("UniPhier FIFO-builtin I2C bus driver"); | |
593 | MODULE_LICENSE("GPL"); |