Commit | Line | Data |
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979b907f ZS |
1 | /* |
2 | * I2C bus driver for CSR SiRFprimaII | |
3 | * | |
4 | * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company. | |
5 | * | |
6 | * Licensed under GPLv2 or later. | |
7 | */ | |
8 | ||
9 | #include <linux/interrupt.h> | |
10 | #include <linux/kernel.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/platform_device.h> | |
14 | #include <linux/i2c.h> | |
15 | #include <linux/clk.h> | |
16 | #include <linux/err.h> | |
17 | #include <linux/io.h> | |
18 | ||
19 | #define SIRFSOC_I2C_CLK_CTRL 0x00 | |
20 | #define SIRFSOC_I2C_STATUS 0x0C | |
21 | #define SIRFSOC_I2C_CTRL 0x10 | |
22 | #define SIRFSOC_I2C_IO_CTRL 0x14 | |
23 | #define SIRFSOC_I2C_SDA_DELAY 0x18 | |
24 | #define SIRFSOC_I2C_CMD_START 0x1C | |
25 | #define SIRFSOC_I2C_CMD_BUF 0x30 | |
26 | #define SIRFSOC_I2C_DATA_BUF 0x80 | |
27 | ||
28 | #define SIRFSOC_I2C_CMD_BUF_MAX 16 | |
29 | #define SIRFSOC_I2C_DATA_BUF_MAX 16 | |
30 | ||
31 | #define SIRFSOC_I2C_CMD(x) (SIRFSOC_I2C_CMD_BUF + (x)*0x04) | |
32 | #define SIRFSOC_I2C_DATA_MASK(x) (0xFF<<(((x)&3)*8)) | |
33 | #define SIRFSOC_I2C_DATA_SHIFT(x) (((x)&3)*8) | |
34 | ||
35 | #define SIRFSOC_I2C_DIV_MASK (0xFFFF) | |
36 | ||
37 | /* I2C status flags */ | |
38 | #define SIRFSOC_I2C_STAT_BUSY BIT(0) | |
39 | #define SIRFSOC_I2C_STAT_TIP BIT(1) | |
40 | #define SIRFSOC_I2C_STAT_NACK BIT(2) | |
41 | #define SIRFSOC_I2C_STAT_TR_INT BIT(4) | |
42 | #define SIRFSOC_I2C_STAT_STOP BIT(6) | |
43 | #define SIRFSOC_I2C_STAT_CMD_DONE BIT(8) | |
44 | #define SIRFSOC_I2C_STAT_ERR BIT(9) | |
45 | #define SIRFSOC_I2C_CMD_INDEX (0x1F<<16) | |
46 | ||
47 | /* I2C control flags */ | |
48 | #define SIRFSOC_I2C_RESET BIT(0) | |
49 | #define SIRFSOC_I2C_CORE_EN BIT(1) | |
50 | #define SIRFSOC_I2C_MASTER_MODE BIT(2) | |
51 | #define SIRFSOC_I2C_CMD_DONE_EN BIT(11) | |
52 | #define SIRFSOC_I2C_ERR_INT_EN BIT(12) | |
53 | ||
54 | #define SIRFSOC_I2C_SDA_DELAY_MASK (0xFF) | |
55 | #define SIRFSOC_I2C_SCLF_FILTER (3<<8) | |
56 | ||
57 | #define SIRFSOC_I2C_START_CMD BIT(0) | |
58 | ||
59 | #define SIRFSOC_I2C_CMD_RP(x) ((x)&0x7) | |
60 | #define SIRFSOC_I2C_NACK BIT(3) | |
61 | #define SIRFSOC_I2C_WRITE BIT(4) | |
62 | #define SIRFSOC_I2C_READ BIT(5) | |
63 | #define SIRFSOC_I2C_STOP BIT(6) | |
64 | #define SIRFSOC_I2C_START BIT(7) | |
65 | ||
66 | #define SIRFSOC_I2C_DEFAULT_SPEED 100000 | |
c984319a ZS |
67 | #define SIRFSOC_I2C_ERR_NOACK 1 |
68 | #define SIRFSOC_I2C_ERR_TIMEOUT 2 | |
979b907f ZS |
69 | |
70 | struct sirfsoc_i2c { | |
71 | void __iomem *base; | |
72 | struct clk *clk; | |
73 | u32 cmd_ptr; /* Current position in CMD buffer */ | |
74 | u8 *buf; /* Buffer passed by user */ | |
75 | u32 msg_len; /* Message length */ | |
76 | u32 finished_len; /* number of bytes read/written */ | |
77 | u32 read_cmd_len; /* number of read cmd sent */ | |
78 | int msg_read; /* 1 indicates a read message */ | |
79 | int err_status; /* 1 indicates an error on bus */ | |
80 | ||
81 | u32 sda_delay; /* For suspend/resume */ | |
82 | u32 clk_div; | |
83 | int last; /* Last message in transfer, STOP cmd can be sent */ | |
84 | ||
85 | struct completion done; /* indicates completion of message transfer */ | |
86 | struct i2c_adapter adapter; | |
87 | }; | |
88 | ||
89 | static void i2c_sirfsoc_read_data(struct sirfsoc_i2c *siic) | |
90 | { | |
91 | u32 data = 0; | |
92 | int i; | |
93 | ||
94 | for (i = 0; i < siic->read_cmd_len; i++) { | |
95 | if (!(i & 0x3)) | |
96 | data = readl(siic->base + SIRFSOC_I2C_DATA_BUF + i); | |
97 | siic->buf[siic->finished_len++] = | |
98 | (u8)((data & SIRFSOC_I2C_DATA_MASK(i)) >> | |
99 | SIRFSOC_I2C_DATA_SHIFT(i)); | |
100 | } | |
101 | } | |
102 | ||
103 | static void i2c_sirfsoc_queue_cmd(struct sirfsoc_i2c *siic) | |
104 | { | |
105 | u32 regval; | |
106 | int i = 0; | |
107 | ||
108 | if (siic->msg_read) { | |
109 | while (((siic->finished_len + i) < siic->msg_len) | |
110 | && (siic->cmd_ptr < SIRFSOC_I2C_CMD_BUF_MAX)) { | |
111 | regval = SIRFSOC_I2C_READ | SIRFSOC_I2C_CMD_RP(0); | |
112 | if (((siic->finished_len + i) == | |
113 | (siic->msg_len - 1)) && siic->last) | |
114 | regval |= SIRFSOC_I2C_STOP | SIRFSOC_I2C_NACK; | |
115 | writel(regval, | |
116 | siic->base + SIRFSOC_I2C_CMD(siic->cmd_ptr++)); | |
117 | i++; | |
118 | } | |
119 | ||
120 | siic->read_cmd_len = i; | |
121 | } else { | |
122 | while ((siic->cmd_ptr < SIRFSOC_I2C_CMD_BUF_MAX - 1) | |
123 | && (siic->finished_len < siic->msg_len)) { | |
124 | regval = SIRFSOC_I2C_WRITE | SIRFSOC_I2C_CMD_RP(0); | |
125 | if ((siic->finished_len == (siic->msg_len - 1)) | |
126 | && siic->last) | |
127 | regval |= SIRFSOC_I2C_STOP; | |
128 | writel(regval, | |
129 | siic->base + SIRFSOC_I2C_CMD(siic->cmd_ptr++)); | |
130 | writel(siic->buf[siic->finished_len++], | |
131 | siic->base + SIRFSOC_I2C_CMD(siic->cmd_ptr++)); | |
132 | } | |
133 | } | |
134 | siic->cmd_ptr = 0; | |
135 | ||
136 | /* Trigger the transfer */ | |
137 | writel(SIRFSOC_I2C_START_CMD, siic->base + SIRFSOC_I2C_CMD_START); | |
138 | } | |
139 | ||
140 | static irqreturn_t i2c_sirfsoc_irq(int irq, void *dev_id) | |
141 | { | |
142 | struct sirfsoc_i2c *siic = (struct sirfsoc_i2c *)dev_id; | |
143 | u32 i2c_stat = readl(siic->base + SIRFSOC_I2C_STATUS); | |
144 | ||
145 | if (i2c_stat & SIRFSOC_I2C_STAT_ERR) { | |
146 | /* Error conditions */ | |
c984319a | 147 | siic->err_status = SIRFSOC_I2C_ERR_NOACK; |
979b907f ZS |
148 | writel(SIRFSOC_I2C_STAT_ERR, siic->base + SIRFSOC_I2C_STATUS); |
149 | ||
150 | if (i2c_stat & SIRFSOC_I2C_STAT_NACK) | |
c984319a | 151 | dev_dbg(&siic->adapter.dev, "ACK not received\n"); |
979b907f ZS |
152 | else |
153 | dev_err(&siic->adapter.dev, "I2C error\n"); | |
154 | ||
c984319a ZS |
155 | /* |
156 | * Due to hardware ANOMALY, we need to reset I2C earlier after | |
157 | * we get NOACK while accessing non-existing clients, otherwise | |
158 | * we will get errors even we access existing clients later | |
159 | */ | |
160 | writel(readl(siic->base + SIRFSOC_I2C_CTRL) | SIRFSOC_I2C_RESET, | |
161 | siic->base + SIRFSOC_I2C_CTRL); | |
162 | while (readl(siic->base + SIRFSOC_I2C_CTRL) & SIRFSOC_I2C_RESET) | |
163 | cpu_relax(); | |
164 | ||
979b907f ZS |
165 | complete(&siic->done); |
166 | } else if (i2c_stat & SIRFSOC_I2C_STAT_CMD_DONE) { | |
167 | /* CMD buffer execution complete */ | |
168 | if (siic->msg_read) | |
169 | i2c_sirfsoc_read_data(siic); | |
170 | if (siic->finished_len == siic->msg_len) | |
171 | complete(&siic->done); | |
172 | else /* Fill a new CMD buffer for left data */ | |
173 | i2c_sirfsoc_queue_cmd(siic); | |
174 | ||
175 | writel(SIRFSOC_I2C_STAT_CMD_DONE, siic->base + SIRFSOC_I2C_STATUS); | |
176 | } | |
177 | ||
178 | return IRQ_HANDLED; | |
179 | } | |
180 | ||
181 | static void i2c_sirfsoc_set_address(struct sirfsoc_i2c *siic, | |
182 | struct i2c_msg *msg) | |
183 | { | |
184 | unsigned char addr; | |
185 | u32 regval = SIRFSOC_I2C_START | SIRFSOC_I2C_CMD_RP(0) | SIRFSOC_I2C_WRITE; | |
186 | ||
187 | /* no data and last message -> add STOP */ | |
188 | if (siic->last && (msg->len == 0)) | |
189 | regval |= SIRFSOC_I2C_STOP; | |
190 | ||
191 | writel(regval, siic->base + SIRFSOC_I2C_CMD(siic->cmd_ptr++)); | |
192 | ||
193 | addr = msg->addr << 1; /* Generate address */ | |
194 | if (msg->flags & I2C_M_RD) | |
195 | addr |= 1; | |
196 | ||
5ebffa6b ZS |
197 | /* Reverse direction bit */ |
198 | if (msg->flags & I2C_M_REV_DIR_ADDR) | |
199 | addr ^= 1; | |
200 | ||
979b907f ZS |
201 | writel(addr, siic->base + SIRFSOC_I2C_CMD(siic->cmd_ptr++)); |
202 | } | |
203 | ||
204 | static int i2c_sirfsoc_xfer_msg(struct sirfsoc_i2c *siic, struct i2c_msg *msg) | |
205 | { | |
206 | u32 regval = readl(siic->base + SIRFSOC_I2C_CTRL); | |
207 | /* timeout waiting for the xfer to finish or fail */ | |
208 | int timeout = msecs_to_jiffies((msg->len + 1) * 50); | |
979b907f ZS |
209 | |
210 | i2c_sirfsoc_set_address(siic, msg); | |
211 | ||
212 | writel(regval | SIRFSOC_I2C_CMD_DONE_EN | SIRFSOC_I2C_ERR_INT_EN, | |
213 | siic->base + SIRFSOC_I2C_CTRL); | |
214 | i2c_sirfsoc_queue_cmd(siic); | |
215 | ||
216 | if (wait_for_completion_timeout(&siic->done, timeout) == 0) { | |
c984319a | 217 | siic->err_status = SIRFSOC_I2C_ERR_TIMEOUT; |
979b907f ZS |
218 | dev_err(&siic->adapter.dev, "Transfer timeout\n"); |
219 | } | |
220 | ||
221 | writel(regval & ~(SIRFSOC_I2C_CMD_DONE_EN | SIRFSOC_I2C_ERR_INT_EN), | |
222 | siic->base + SIRFSOC_I2C_CTRL); | |
223 | writel(0, siic->base + SIRFSOC_I2C_CMD_START); | |
224 | ||
c984319a ZS |
225 | /* i2c control doesn't response, reset it */ |
226 | if (siic->err_status == SIRFSOC_I2C_ERR_TIMEOUT) { | |
979b907f ZS |
227 | writel(readl(siic->base + SIRFSOC_I2C_CTRL) | SIRFSOC_I2C_RESET, |
228 | siic->base + SIRFSOC_I2C_CTRL); | |
229 | while (readl(siic->base + SIRFSOC_I2C_CTRL) & SIRFSOC_I2C_RESET) | |
230 | cpu_relax(); | |
979b907f | 231 | } |
617da00c | 232 | return siic->err_status ? -EAGAIN : 0; |
979b907f ZS |
233 | } |
234 | ||
235 | static u32 i2c_sirfsoc_func(struct i2c_adapter *adap) | |
236 | { | |
237 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; | |
238 | } | |
239 | ||
240 | static int i2c_sirfsoc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, | |
241 | int num) | |
242 | { | |
243 | struct sirfsoc_i2c *siic = adap->algo_data; | |
244 | int i, ret; | |
245 | ||
246 | clk_enable(siic->clk); | |
247 | ||
248 | for (i = 0; i < num; i++) { | |
249 | siic->buf = msgs[i].buf; | |
250 | siic->msg_len = msgs[i].len; | |
251 | siic->msg_read = !!(msgs[i].flags & I2C_M_RD); | |
252 | siic->err_status = 0; | |
253 | siic->cmd_ptr = 0; | |
254 | siic->finished_len = 0; | |
255 | siic->last = (i == (num - 1)); | |
256 | ||
257 | ret = i2c_sirfsoc_xfer_msg(siic, &msgs[i]); | |
258 | if (ret) { | |
259 | clk_disable(siic->clk); | |
260 | return ret; | |
261 | } | |
262 | } | |
263 | ||
264 | clk_disable(siic->clk); | |
265 | return num; | |
266 | } | |
267 | ||
268 | /* I2C algorithms associated with this master controller driver */ | |
269 | static const struct i2c_algorithm i2c_sirfsoc_algo = { | |
270 | .master_xfer = i2c_sirfsoc_xfer, | |
271 | .functionality = i2c_sirfsoc_func, | |
272 | }; | |
273 | ||
0b255e92 | 274 | static int i2c_sirfsoc_probe(struct platform_device *pdev) |
979b907f ZS |
275 | { |
276 | struct sirfsoc_i2c *siic; | |
277 | struct i2c_adapter *adap; | |
278 | struct resource *mem_res; | |
279 | struct clk *clk; | |
280 | int bitrate; | |
281 | int ctrl_speed; | |
282 | int irq; | |
283 | ||
284 | int err; | |
285 | u32 regval; | |
286 | ||
287 | clk = clk_get(&pdev->dev, NULL); | |
288 | if (IS_ERR(clk)) { | |
289 | err = PTR_ERR(clk); | |
290 | dev_err(&pdev->dev, "Clock get failed\n"); | |
291 | goto err_get_clk; | |
292 | } | |
293 | ||
294 | err = clk_prepare(clk); | |
295 | if (err) { | |
296 | dev_err(&pdev->dev, "Clock prepare failed\n"); | |
297 | goto err_clk_prep; | |
298 | } | |
299 | ||
300 | err = clk_enable(clk); | |
301 | if (err) { | |
302 | dev_err(&pdev->dev, "Clock enable failed\n"); | |
303 | goto err_clk_en; | |
304 | } | |
305 | ||
306 | ctrl_speed = clk_get_rate(clk); | |
307 | ||
308 | siic = devm_kzalloc(&pdev->dev, sizeof(*siic), GFP_KERNEL); | |
309 | if (!siic) { | |
979b907f ZS |
310 | err = -ENOMEM; |
311 | goto out; | |
312 | } | |
313 | adap = &siic->adapter; | |
ca9c77cd | 314 | adap->class = I2C_CLASS_DEPRECATED; |
979b907f ZS |
315 | |
316 | mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
84dbf809 TR |
317 | siic->base = devm_ioremap_resource(&pdev->dev, mem_res); |
318 | if (IS_ERR(siic->base)) { | |
319 | err = PTR_ERR(siic->base); | |
979b907f ZS |
320 | goto out; |
321 | } | |
322 | ||
323 | irq = platform_get_irq(pdev, 0); | |
324 | if (irq < 0) { | |
325 | err = irq; | |
326 | goto out; | |
327 | } | |
328 | err = devm_request_irq(&pdev->dev, irq, i2c_sirfsoc_irq, 0, | |
329 | dev_name(&pdev->dev), siic); | |
330 | if (err) | |
331 | goto out; | |
332 | ||
333 | adap->algo = &i2c_sirfsoc_algo; | |
334 | adap->algo_data = siic; | |
617da00c | 335 | adap->retries = 3; |
979b907f | 336 | |
bfd059da | 337 | adap->dev.of_node = pdev->dev.of_node; |
979b907f ZS |
338 | adap->dev.parent = &pdev->dev; |
339 | adap->nr = pdev->id; | |
340 | ||
341 | strlcpy(adap->name, "sirfsoc-i2c", sizeof(adap->name)); | |
342 | ||
343 | platform_set_drvdata(pdev, adap); | |
344 | init_completion(&siic->done); | |
345 | ||
346 | /* Controller Initalisation */ | |
347 | ||
348 | writel(SIRFSOC_I2C_RESET, siic->base + SIRFSOC_I2C_CTRL); | |
349 | while (readl(siic->base + SIRFSOC_I2C_CTRL) & SIRFSOC_I2C_RESET) | |
350 | cpu_relax(); | |
351 | writel(SIRFSOC_I2C_CORE_EN | SIRFSOC_I2C_MASTER_MODE, | |
352 | siic->base + SIRFSOC_I2C_CTRL); | |
353 | ||
354 | siic->clk = clk; | |
355 | ||
356 | err = of_property_read_u32(pdev->dev.of_node, | |
357 | "clock-frequency", &bitrate); | |
358 | if (err < 0) | |
359 | bitrate = SIRFSOC_I2C_DEFAULT_SPEED; | |
360 | ||
361 | if (bitrate < 100000) | |
362 | regval = | |
4602bf16 | 363 | (2 * ctrl_speed) / (bitrate * 11); |
979b907f ZS |
364 | else |
365 | regval = ctrl_speed / (bitrate * 5); | |
366 | ||
367 | writel(regval, siic->base + SIRFSOC_I2C_CLK_CTRL); | |
368 | if (regval > 0xFF) | |
369 | writel(0xFF, siic->base + SIRFSOC_I2C_SDA_DELAY); | |
370 | else | |
371 | writel(regval, siic->base + SIRFSOC_I2C_SDA_DELAY); | |
372 | ||
373 | err = i2c_add_numbered_adapter(adap); | |
374 | if (err < 0) { | |
375 | dev_err(&pdev->dev, "Can't add new i2c adapter\n"); | |
376 | goto out; | |
377 | } | |
378 | ||
379 | clk_disable(clk); | |
380 | ||
381 | dev_info(&pdev->dev, " I2C adapter ready to operate\n"); | |
382 | ||
383 | return 0; | |
384 | ||
385 | out: | |
386 | clk_disable(clk); | |
387 | err_clk_en: | |
388 | clk_unprepare(clk); | |
389 | err_clk_prep: | |
390 | clk_put(clk); | |
391 | err_get_clk: | |
392 | return err; | |
393 | } | |
394 | ||
0b255e92 | 395 | static int i2c_sirfsoc_remove(struct platform_device *pdev) |
979b907f ZS |
396 | { |
397 | struct i2c_adapter *adapter = platform_get_drvdata(pdev); | |
398 | struct sirfsoc_i2c *siic = adapter->algo_data; | |
399 | ||
400 | writel(SIRFSOC_I2C_RESET, siic->base + SIRFSOC_I2C_CTRL); | |
401 | i2c_del_adapter(adapter); | |
402 | clk_unprepare(siic->clk); | |
403 | clk_put(siic->clk); | |
404 | return 0; | |
405 | } | |
406 | ||
407 | #ifdef CONFIG_PM | |
408 | static int i2c_sirfsoc_suspend(struct device *dev) | |
409 | { | |
410 | struct platform_device *pdev = to_platform_device(dev); | |
411 | struct i2c_adapter *adapter = platform_get_drvdata(pdev); | |
412 | struct sirfsoc_i2c *siic = adapter->algo_data; | |
413 | ||
414 | clk_enable(siic->clk); | |
415 | siic->sda_delay = readl(siic->base + SIRFSOC_I2C_SDA_DELAY); | |
416 | siic->clk_div = readl(siic->base + SIRFSOC_I2C_CLK_CTRL); | |
417 | clk_disable(siic->clk); | |
418 | return 0; | |
419 | } | |
420 | ||
421 | static int i2c_sirfsoc_resume(struct device *dev) | |
422 | { | |
423 | struct platform_device *pdev = to_platform_device(dev); | |
424 | struct i2c_adapter *adapter = platform_get_drvdata(pdev); | |
425 | struct sirfsoc_i2c *siic = adapter->algo_data; | |
426 | ||
427 | clk_enable(siic->clk); | |
428 | writel(SIRFSOC_I2C_RESET, siic->base + SIRFSOC_I2C_CTRL); | |
ebae7dfa ZS |
429 | while (readl(siic->base + SIRFSOC_I2C_CTRL) & SIRFSOC_I2C_RESET) |
430 | cpu_relax(); | |
979b907f ZS |
431 | writel(SIRFSOC_I2C_CORE_EN | SIRFSOC_I2C_MASTER_MODE, |
432 | siic->base + SIRFSOC_I2C_CTRL); | |
433 | writel(siic->clk_div, siic->base + SIRFSOC_I2C_CLK_CTRL); | |
434 | writel(siic->sda_delay, siic->base + SIRFSOC_I2C_SDA_DELAY); | |
435 | clk_disable(siic->clk); | |
436 | return 0; | |
437 | } | |
438 | ||
439 | static const struct dev_pm_ops i2c_sirfsoc_pm_ops = { | |
440 | .suspend = i2c_sirfsoc_suspend, | |
441 | .resume = i2c_sirfsoc_resume, | |
442 | }; | |
443 | #endif | |
444 | ||
0b255e92 | 445 | static const struct of_device_id sirfsoc_i2c_of_match[] = { |
979b907f ZS |
446 | { .compatible = "sirf,prima2-i2c", }, |
447 | {}, | |
448 | }; | |
449 | MODULE_DEVICE_TABLE(of, sirfsoc_i2c_of_match); | |
450 | ||
451 | static struct platform_driver i2c_sirfsoc_driver = { | |
452 | .driver = { | |
453 | .name = "sirfsoc_i2c", | |
979b907f ZS |
454 | #ifdef CONFIG_PM |
455 | .pm = &i2c_sirfsoc_pm_ops, | |
456 | #endif | |
457 | .of_match_table = sirfsoc_i2c_of_match, | |
458 | }, | |
459 | .probe = i2c_sirfsoc_probe, | |
0b255e92 | 460 | .remove = i2c_sirfsoc_remove, |
979b907f ZS |
461 | }; |
462 | module_platform_driver(i2c_sirfsoc_driver); | |
463 | ||
464 | MODULE_DESCRIPTION("SiRF SoC I2C master controller driver"); | |
465 | MODULE_AUTHOR("Zhiwu Song <Zhiwu.Song@csr.com>, " | |
466 | "Xiangzhen Ye <Xiangzhen.Ye@csr.com>"); | |
467 | MODULE_LICENSE("GPL v2"); |