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1 | /** |
2 | * i2c-exynos5.c - Samsung Exynos5 I2C Controller Driver | |
3 | * | |
4 | * Copyright (C) 2013 Samsung Electronics Co., Ltd. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | */ | |
10 | ||
11 | #include <linux/kernel.h> | |
12 | #include <linux/module.h> | |
13 | ||
14 | #include <linux/i2c.h> | |
15 | #include <linux/init.h> | |
16 | #include <linux/time.h> | |
17 | #include <linux/interrupt.h> | |
18 | #include <linux/delay.h> | |
19 | #include <linux/errno.h> | |
20 | #include <linux/err.h> | |
21 | #include <linux/platform_device.h> | |
22 | #include <linux/clk.h> | |
23 | #include <linux/slab.h> | |
24 | #include <linux/io.h> | |
25 | #include <linux/of_address.h> | |
26 | #include <linux/of_irq.h> | |
27 | #include <linux/spinlock.h> | |
28 | ||
29 | /* | |
30 | * HSI2C controller from Samsung supports 2 modes of operation | |
31 | * 1. Auto mode: Where in master automatically controls the whole transaction | |
32 | * 2. Manual mode: Software controls the transaction by issuing commands | |
33 | * START, READ, WRITE, STOP, RESTART in I2C_MANUAL_CMD register. | |
34 | * | |
35 | * Operation mode can be selected by setting AUTO_MODE bit in I2C_CONF register | |
36 | * | |
37 | * Special bits are available for both modes of operation to set commands | |
38 | * and for checking transfer status | |
39 | */ | |
40 | ||
41 | /* Register Map */ | |
42 | #define HSI2C_CTL 0x00 | |
43 | #define HSI2C_FIFO_CTL 0x04 | |
44 | #define HSI2C_TRAILIG_CTL 0x08 | |
45 | #define HSI2C_CLK_CTL 0x0C | |
46 | #define HSI2C_CLK_SLOT 0x10 | |
47 | #define HSI2C_INT_ENABLE 0x20 | |
48 | #define HSI2C_INT_STATUS 0x24 | |
49 | #define HSI2C_ERR_STATUS 0x2C | |
50 | #define HSI2C_FIFO_STATUS 0x30 | |
51 | #define HSI2C_TX_DATA 0x34 | |
52 | #define HSI2C_RX_DATA 0x38 | |
53 | #define HSI2C_CONF 0x40 | |
54 | #define HSI2C_AUTO_CONF 0x44 | |
55 | #define HSI2C_TIMEOUT 0x48 | |
56 | #define HSI2C_MANUAL_CMD 0x4C | |
57 | #define HSI2C_TRANS_STATUS 0x50 | |
58 | #define HSI2C_TIMING_HS1 0x54 | |
59 | #define HSI2C_TIMING_HS2 0x58 | |
60 | #define HSI2C_TIMING_HS3 0x5C | |
61 | #define HSI2C_TIMING_FS1 0x60 | |
62 | #define HSI2C_TIMING_FS2 0x64 | |
63 | #define HSI2C_TIMING_FS3 0x68 | |
64 | #define HSI2C_TIMING_SLA 0x6C | |
65 | #define HSI2C_ADDR 0x70 | |
66 | ||
67 | /* I2C_CTL Register bits */ | |
68 | #define HSI2C_FUNC_MODE_I2C (1u << 0) | |
69 | #define HSI2C_MASTER (1u << 3) | |
70 | #define HSI2C_RXCHON (1u << 6) | |
71 | #define HSI2C_TXCHON (1u << 7) | |
72 | #define HSI2C_SW_RST (1u << 31) | |
73 | ||
74 | /* I2C_FIFO_CTL Register bits */ | |
75 | #define HSI2C_RXFIFO_EN (1u << 0) | |
76 | #define HSI2C_TXFIFO_EN (1u << 1) | |
77 | #define HSI2C_RXFIFO_TRIGGER_LEVEL(x) ((x) << 4) | |
78 | #define HSI2C_TXFIFO_TRIGGER_LEVEL(x) ((x) << 16) | |
79 | ||
80 | /* As per user manual FIFO max depth is 64bytes */ | |
81 | #define HSI2C_FIFO_MAX 0x40 | |
82 | /* default trigger levels for Tx and Rx FIFOs */ | |
83 | #define HSI2C_DEF_TXFIFO_LVL (HSI2C_FIFO_MAX - 0x30) | |
84 | #define HSI2C_DEF_RXFIFO_LVL (HSI2C_FIFO_MAX - 0x10) | |
85 | ||
86 | /* I2C_TRAILING_CTL Register bits */ | |
87 | #define HSI2C_TRAILING_COUNT (0xf) | |
88 | ||
89 | /* I2C_INT_EN Register bits */ | |
90 | #define HSI2C_INT_TX_ALMOSTEMPTY_EN (1u << 0) | |
91 | #define HSI2C_INT_RX_ALMOSTFULL_EN (1u << 1) | |
92 | #define HSI2C_INT_TRAILING_EN (1u << 6) | |
93 | #define HSI2C_INT_I2C_EN (1u << 9) | |
94 | ||
95 | /* I2C_INT_STAT Register bits */ | |
96 | #define HSI2C_INT_TX_ALMOSTEMPTY (1u << 0) | |
97 | #define HSI2C_INT_RX_ALMOSTFULL (1u << 1) | |
98 | #define HSI2C_INT_TX_UNDERRUN (1u << 2) | |
99 | #define HSI2C_INT_TX_OVERRUN (1u << 3) | |
100 | #define HSI2C_INT_RX_UNDERRUN (1u << 4) | |
101 | #define HSI2C_INT_RX_OVERRUN (1u << 5) | |
102 | #define HSI2C_INT_TRAILING (1u << 6) | |
103 | #define HSI2C_INT_I2C (1u << 9) | |
104 | ||
105 | /* I2C_FIFO_STAT Register bits */ | |
106 | #define HSI2C_RX_FIFO_EMPTY (1u << 24) | |
107 | #define HSI2C_RX_FIFO_FULL (1u << 23) | |
108 | #define HSI2C_RX_FIFO_LVL(x) ((x >> 16) & 0x7f) | |
109 | #define HSI2C_TX_FIFO_EMPTY (1u << 8) | |
110 | #define HSI2C_TX_FIFO_FULL (1u << 7) | |
111 | #define HSI2C_TX_FIFO_LVL(x) ((x >> 0) & 0x7f) | |
112 | ||
113 | /* I2C_CONF Register bits */ | |
114 | #define HSI2C_AUTO_MODE (1u << 31) | |
115 | #define HSI2C_10BIT_ADDR_MODE (1u << 30) | |
116 | #define HSI2C_HS_MODE (1u << 29) | |
117 | ||
118 | /* I2C_AUTO_CONF Register bits */ | |
119 | #define HSI2C_READ_WRITE (1u << 16) | |
120 | #define HSI2C_STOP_AFTER_TRANS (1u << 17) | |
121 | #define HSI2C_MASTER_RUN (1u << 31) | |
122 | ||
123 | /* I2C_TIMEOUT Register bits */ | |
124 | #define HSI2C_TIMEOUT_EN (1u << 31) | |
125 | #define HSI2C_TIMEOUT_MASK 0xff | |
126 | ||
127 | /* I2C_TRANS_STATUS register bits */ | |
128 | #define HSI2C_MASTER_BUSY (1u << 17) | |
129 | #define HSI2C_SLAVE_BUSY (1u << 16) | |
130 | #define HSI2C_TIMEOUT_AUTO (1u << 4) | |
131 | #define HSI2C_NO_DEV (1u << 3) | |
132 | #define HSI2C_NO_DEV_ACK (1u << 2) | |
133 | #define HSI2C_TRANS_ABORT (1u << 1) | |
134 | #define HSI2C_TRANS_DONE (1u << 0) | |
135 | ||
136 | /* I2C_ADDR register bits */ | |
137 | #define HSI2C_SLV_ADDR_SLV(x) ((x & 0x3ff) << 0) | |
138 | #define HSI2C_SLV_ADDR_MAS(x) ((x & 0x3ff) << 10) | |
139 | #define HSI2C_MASTER_ID(x) ((x & 0xff) << 24) | |
140 | #define MASTER_ID(x) ((x & 0x7) + 0x08) | |
141 | ||
142 | /* | |
143 | * Controller operating frequency, timing values for operation | |
144 | * are calculated against this frequency | |
145 | */ | |
146 | #define HSI2C_HS_TX_CLOCK 1000000 | |
147 | #define HSI2C_FS_TX_CLOCK 100000 | |
148 | #define HSI2C_HIGH_SPD 1 | |
149 | #define HSI2C_FAST_SPD 0 | |
150 | ||
151 | #define EXYNOS5_I2C_TIMEOUT (msecs_to_jiffies(1000)) | |
152 | ||
153 | struct exynos5_i2c { | |
154 | struct i2c_adapter adap; | |
155 | unsigned int suspended:1; | |
156 | ||
157 | struct i2c_msg *msg; | |
158 | struct completion msg_complete; | |
159 | unsigned int msg_ptr; | |
160 | ||
161 | unsigned int irq; | |
162 | ||
163 | void __iomem *regs; | |
164 | struct clk *clk; | |
165 | struct device *dev; | |
166 | int state; | |
167 | ||
168 | spinlock_t lock; /* IRQ synchronization */ | |
169 | ||
170 | /* | |
171 | * Since the TRANS_DONE bit is cleared on read, and we may read it | |
172 | * either during an IRQ or after a transaction, keep track of its | |
173 | * state here. | |
174 | */ | |
175 | int trans_done; | |
176 | ||
177 | /* Controller operating frequency */ | |
178 | unsigned int fs_clock; | |
179 | unsigned int hs_clock; | |
180 | ||
181 | /* | |
182 | * HSI2C Controller can operate in | |
183 | * 1. High speed upto 3.4Mbps | |
184 | * 2. Fast speed upto 1Mbps | |
185 | */ | |
186 | int speed_mode; | |
187 | }; | |
188 | ||
189 | static const struct of_device_id exynos5_i2c_match[] = { | |
190 | { .compatible = "samsung,exynos5-hsi2c" }, | |
191 | {}, | |
192 | }; | |
193 | MODULE_DEVICE_TABLE(of, exynos5_i2c_match); | |
194 | ||
195 | static void exynos5_i2c_clr_pend_irq(struct exynos5_i2c *i2c) | |
196 | { | |
197 | writel(readl(i2c->regs + HSI2C_INT_STATUS), | |
198 | i2c->regs + HSI2C_INT_STATUS); | |
199 | } | |
200 | ||
201 | /* | |
202 | * exynos5_i2c_set_timing: updates the registers with appropriate | |
203 | * timing values calculated | |
204 | * | |
205 | * Returns 0 on success, -EINVAL if the cycle length cannot | |
206 | * be calculated. | |
207 | */ | |
208 | static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, int mode) | |
209 | { | |
210 | u32 i2c_timing_s1; | |
211 | u32 i2c_timing_s2; | |
212 | u32 i2c_timing_s3; | |
213 | u32 i2c_timing_sla; | |
214 | unsigned int t_start_su, t_start_hd; | |
215 | unsigned int t_stop_su; | |
216 | unsigned int t_data_su, t_data_hd; | |
217 | unsigned int t_scl_l, t_scl_h; | |
218 | unsigned int t_sr_release; | |
219 | unsigned int t_ftl_cycle; | |
220 | unsigned int clkin = clk_get_rate(i2c->clk); | |
221 | unsigned int div, utemp0 = 0, utemp1 = 0, clk_cycle; | |
222 | unsigned int op_clk = (mode == HSI2C_HIGH_SPD) ? | |
223 | i2c->hs_clock : i2c->fs_clock; | |
224 | ||
225 | /* | |
226 | * FPCLK / FI2C = | |
227 | * (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) + 8 + 2 * FLT_CYCLE | |
228 | * utemp0 = (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) | |
229 | * utemp1 = (TSCLK_L + TSCLK_H + 2) | |
230 | */ | |
231 | t_ftl_cycle = (readl(i2c->regs + HSI2C_CONF) >> 16) & 0x7; | |
232 | utemp0 = (clkin / op_clk) - 8 - 2 * t_ftl_cycle; | |
233 | ||
234 | /* CLK_DIV max is 256 */ | |
235 | for (div = 0; div < 256; div++) { | |
236 | utemp1 = utemp0 / (div + 1); | |
237 | ||
238 | /* | |
239 | * SCL_L and SCL_H each has max value of 255 | |
240 | * Hence, For the clk_cycle to the have right value | |
241 | * utemp1 has to be less then 512 and more than 4. | |
242 | */ | |
243 | if ((utemp1 < 512) && (utemp1 > 4)) { | |
244 | clk_cycle = utemp1 - 2; | |
245 | break; | |
246 | } else if (div == 255) { | |
247 | dev_warn(i2c->dev, "Failed to calculate divisor"); | |
248 | return -EINVAL; | |
249 | } | |
250 | } | |
251 | ||
252 | t_scl_l = clk_cycle / 2; | |
253 | t_scl_h = clk_cycle / 2; | |
254 | t_start_su = t_scl_l; | |
255 | t_start_hd = t_scl_l; | |
256 | t_stop_su = t_scl_l; | |
257 | t_data_su = t_scl_l / 2; | |
258 | t_data_hd = t_scl_l / 2; | |
259 | t_sr_release = clk_cycle; | |
260 | ||
261 | i2c_timing_s1 = t_start_su << 24 | t_start_hd << 16 | t_stop_su << 8; | |
262 | i2c_timing_s2 = t_data_su << 24 | t_scl_l << 8 | t_scl_h << 0; | |
263 | i2c_timing_s3 = div << 16 | t_sr_release << 0; | |
264 | i2c_timing_sla = t_data_hd << 0; | |
265 | ||
266 | dev_dbg(i2c->dev, "tSTART_SU: %X, tSTART_HD: %X, tSTOP_SU: %X\n", | |
267 | t_start_su, t_start_hd, t_stop_su); | |
268 | dev_dbg(i2c->dev, "tDATA_SU: %X, tSCL_L: %X, tSCL_H: %X\n", | |
269 | t_data_su, t_scl_l, t_scl_h); | |
270 | dev_dbg(i2c->dev, "nClkDiv: %X, tSR_RELEASE: %X\n", | |
271 | div, t_sr_release); | |
272 | dev_dbg(i2c->dev, "tDATA_HD: %X\n", t_data_hd); | |
273 | ||
274 | if (mode == HSI2C_HIGH_SPD) { | |
275 | writel(i2c_timing_s1, i2c->regs + HSI2C_TIMING_HS1); | |
276 | writel(i2c_timing_s2, i2c->regs + HSI2C_TIMING_HS2); | |
277 | writel(i2c_timing_s3, i2c->regs + HSI2C_TIMING_HS3); | |
278 | } else { | |
279 | writel(i2c_timing_s1, i2c->regs + HSI2C_TIMING_FS1); | |
280 | writel(i2c_timing_s2, i2c->regs + HSI2C_TIMING_FS2); | |
281 | writel(i2c_timing_s3, i2c->regs + HSI2C_TIMING_FS3); | |
282 | } | |
283 | writel(i2c_timing_sla, i2c->regs + HSI2C_TIMING_SLA); | |
284 | ||
285 | return 0; | |
286 | } | |
287 | ||
288 | static int exynos5_hsi2c_clock_setup(struct exynos5_i2c *i2c) | |
289 | { | |
290 | /* | |
291 | * Configure the Fast speed timing values | |
292 | * Even the High Speed mode initially starts with Fast mode | |
293 | */ | |
294 | if (exynos5_i2c_set_timing(i2c, HSI2C_FAST_SPD)) { | |
295 | dev_err(i2c->dev, "HSI2C FS Clock set up failed\n"); | |
296 | return -EINVAL; | |
297 | } | |
298 | ||
299 | /* configure the High speed timing values */ | |
300 | if (i2c->speed_mode == HSI2C_HIGH_SPD) { | |
301 | if (exynos5_i2c_set_timing(i2c, HSI2C_HIGH_SPD)) { | |
302 | dev_err(i2c->dev, "HSI2C HS Clock set up failed\n"); | |
303 | return -EINVAL; | |
304 | } | |
305 | } | |
306 | ||
307 | return 0; | |
308 | } | |
309 | ||
310 | /* | |
311 | * exynos5_i2c_init: configures the controller for I2C functionality | |
312 | * Programs I2C controller for Master mode operation | |
313 | */ | |
314 | static void exynos5_i2c_init(struct exynos5_i2c *i2c) | |
315 | { | |
316 | u32 i2c_conf = readl(i2c->regs + HSI2C_CONF); | |
317 | u32 i2c_timeout = readl(i2c->regs + HSI2C_TIMEOUT); | |
318 | ||
319 | /* Clear to disable Timeout */ | |
320 | i2c_timeout &= ~HSI2C_TIMEOUT_EN; | |
321 | writel(i2c_timeout, i2c->regs + HSI2C_TIMEOUT); | |
322 | ||
323 | writel((HSI2C_FUNC_MODE_I2C | HSI2C_MASTER), | |
324 | i2c->regs + HSI2C_CTL); | |
325 | writel(HSI2C_TRAILING_COUNT, i2c->regs + HSI2C_TRAILIG_CTL); | |
326 | ||
327 | if (i2c->speed_mode == HSI2C_HIGH_SPD) { | |
328 | writel(HSI2C_MASTER_ID(MASTER_ID(i2c->adap.nr)), | |
329 | i2c->regs + HSI2C_ADDR); | |
330 | i2c_conf |= HSI2C_HS_MODE; | |
331 | } | |
332 | ||
333 | writel(i2c_conf | HSI2C_AUTO_MODE, i2c->regs + HSI2C_CONF); | |
334 | } | |
335 | ||
336 | static void exynos5_i2c_reset(struct exynos5_i2c *i2c) | |
337 | { | |
338 | u32 i2c_ctl; | |
339 | ||
340 | /* Set and clear the bit for reset */ | |
341 | i2c_ctl = readl(i2c->regs + HSI2C_CTL); | |
342 | i2c_ctl |= HSI2C_SW_RST; | |
343 | writel(i2c_ctl, i2c->regs + HSI2C_CTL); | |
344 | ||
345 | i2c_ctl = readl(i2c->regs + HSI2C_CTL); | |
346 | i2c_ctl &= ~HSI2C_SW_RST; | |
347 | writel(i2c_ctl, i2c->regs + HSI2C_CTL); | |
348 | ||
349 | /* We don't expect calculations to fail during the run */ | |
350 | exynos5_hsi2c_clock_setup(i2c); | |
351 | /* Initialize the configure registers */ | |
352 | exynos5_i2c_init(i2c); | |
353 | } | |
354 | ||
355 | /* | |
356 | * exynos5_i2c_irq: top level IRQ servicing routine | |
357 | * | |
358 | * INT_STATUS registers gives the interrupt details. Further, | |
359 | * FIFO_STATUS or TRANS_STATUS registers are to be check for detailed | |
360 | * state of the bus. | |
361 | */ | |
362 | static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id) | |
363 | { | |
364 | struct exynos5_i2c *i2c = dev_id; | |
365 | u32 fifo_level, int_status, fifo_status, trans_status; | |
366 | unsigned char byte; | |
367 | int len = 0; | |
368 | ||
369 | i2c->state = -EINVAL; | |
370 | ||
371 | spin_lock(&i2c->lock); | |
372 | ||
373 | int_status = readl(i2c->regs + HSI2C_INT_STATUS); | |
374 | writel(int_status, i2c->regs + HSI2C_INT_STATUS); | |
375 | fifo_status = readl(i2c->regs + HSI2C_FIFO_STATUS); | |
376 | ||
377 | /* handle interrupt related to the transfer status */ | |
378 | if (int_status & HSI2C_INT_I2C) { | |
379 | trans_status = readl(i2c->regs + HSI2C_TRANS_STATUS); | |
380 | if (trans_status & HSI2C_NO_DEV_ACK) { | |
381 | dev_dbg(i2c->dev, "No ACK from device\n"); | |
382 | i2c->state = -ENXIO; | |
383 | goto stop; | |
384 | } else if (trans_status & HSI2C_NO_DEV) { | |
385 | dev_dbg(i2c->dev, "No device\n"); | |
386 | i2c->state = -ENXIO; | |
387 | goto stop; | |
388 | } else if (trans_status & HSI2C_TRANS_ABORT) { | |
389 | dev_dbg(i2c->dev, "Deal with arbitration lose\n"); | |
390 | i2c->state = -EAGAIN; | |
391 | goto stop; | |
392 | } else if (trans_status & HSI2C_TIMEOUT_AUTO) { | |
393 | dev_dbg(i2c->dev, "Accessing device timed out\n"); | |
394 | i2c->state = -EAGAIN; | |
395 | goto stop; | |
396 | } else if (trans_status & HSI2C_TRANS_DONE) { | |
397 | i2c->trans_done = 1; | |
398 | i2c->state = 0; | |
399 | } | |
400 | } | |
401 | ||
402 | if ((i2c->msg->flags & I2C_M_RD) && (int_status & | |
403 | (HSI2C_INT_TRAILING | HSI2C_INT_RX_ALMOSTFULL))) { | |
404 | fifo_status = readl(i2c->regs + HSI2C_FIFO_STATUS); | |
405 | fifo_level = HSI2C_RX_FIFO_LVL(fifo_status); | |
406 | len = min(fifo_level, i2c->msg->len - i2c->msg_ptr); | |
407 | ||
408 | while (len > 0) { | |
409 | byte = (unsigned char) | |
410 | readl(i2c->regs + HSI2C_RX_DATA); | |
411 | i2c->msg->buf[i2c->msg_ptr++] = byte; | |
412 | len--; | |
413 | } | |
414 | i2c->state = 0; | |
415 | } else if (int_status & HSI2C_INT_TX_ALMOSTEMPTY) { | |
416 | fifo_status = readl(i2c->regs + HSI2C_FIFO_STATUS); | |
417 | fifo_level = HSI2C_TX_FIFO_LVL(fifo_status); | |
418 | ||
419 | len = HSI2C_FIFO_MAX - fifo_level; | |
420 | if (len > (i2c->msg->len - i2c->msg_ptr)) | |
421 | len = i2c->msg->len - i2c->msg_ptr; | |
422 | ||
423 | while (len > 0) { | |
424 | byte = i2c->msg->buf[i2c->msg_ptr++]; | |
425 | writel(byte, i2c->regs + HSI2C_TX_DATA); | |
426 | len--; | |
427 | } | |
428 | i2c->state = 0; | |
429 | } | |
430 | ||
431 | stop: | |
432 | if ((i2c->trans_done && (i2c->msg->len == i2c->msg_ptr)) || | |
433 | (i2c->state < 0)) { | |
434 | writel(0, i2c->regs + HSI2C_INT_ENABLE); | |
435 | exynos5_i2c_clr_pend_irq(i2c); | |
436 | complete(&i2c->msg_complete); | |
437 | } | |
438 | ||
439 | spin_unlock(&i2c->lock); | |
440 | ||
441 | return IRQ_HANDLED; | |
442 | } | |
443 | ||
444 | /* | |
445 | * exynos5_i2c_wait_bus_idle | |
446 | * | |
447 | * Wait for the bus to go idle, indicated by the MASTER_BUSY bit being | |
448 | * cleared. | |
449 | * | |
450 | * Returns -EBUSY if the bus cannot be bought to idle | |
451 | */ | |
452 | static int exynos5_i2c_wait_bus_idle(struct exynos5_i2c *i2c) | |
453 | { | |
454 | unsigned long stop_time; | |
455 | u32 trans_status; | |
456 | ||
457 | /* wait for 100 milli seconds for the bus to be idle */ | |
458 | stop_time = jiffies + msecs_to_jiffies(100) + 1; | |
459 | do { | |
460 | trans_status = readl(i2c->regs + HSI2C_TRANS_STATUS); | |
461 | if (!(trans_status & HSI2C_MASTER_BUSY)) | |
462 | return 0; | |
463 | ||
464 | usleep_range(50, 200); | |
465 | } while (time_before(jiffies, stop_time)); | |
466 | ||
467 | return -EBUSY; | |
468 | } | |
469 | ||
470 | /* | |
471 | * exynos5_i2c_message_start: Configures the bus and starts the xfer | |
472 | * i2c: struct exynos5_i2c pointer for the current bus | |
473 | * stop: Enables stop after transfer if set. Set for last transfer of | |
474 | * in the list of messages. | |
475 | * | |
476 | * Configures the bus for read/write function | |
477 | * Sets chip address to talk to, message length to be sent. | |
478 | * Enables appropriate interrupts and sends start xfer command. | |
479 | */ | |
480 | static void exynos5_i2c_message_start(struct exynos5_i2c *i2c, int stop) | |
481 | { | |
482 | u32 i2c_ctl; | |
483 | u32 int_en = HSI2C_INT_I2C_EN; | |
484 | u32 i2c_auto_conf = 0; | |
485 | u32 fifo_ctl; | |
486 | unsigned long flags; | |
487 | ||
488 | i2c_ctl = readl(i2c->regs + HSI2C_CTL); | |
489 | i2c_ctl &= ~(HSI2C_TXCHON | HSI2C_RXCHON); | |
490 | fifo_ctl = HSI2C_RXFIFO_EN | HSI2C_TXFIFO_EN; | |
491 | ||
492 | if (i2c->msg->flags & I2C_M_RD) { | |
493 | i2c_ctl |= HSI2C_RXCHON; | |
494 | ||
495 | i2c_auto_conf = HSI2C_READ_WRITE; | |
496 | ||
497 | fifo_ctl |= HSI2C_RXFIFO_TRIGGER_LEVEL(HSI2C_DEF_TXFIFO_LVL); | |
498 | int_en |= (HSI2C_INT_RX_ALMOSTFULL_EN | | |
499 | HSI2C_INT_TRAILING_EN); | |
500 | } else { | |
501 | i2c_ctl |= HSI2C_TXCHON; | |
502 | ||
503 | fifo_ctl |= HSI2C_TXFIFO_TRIGGER_LEVEL(HSI2C_DEF_RXFIFO_LVL); | |
504 | int_en |= HSI2C_INT_TX_ALMOSTEMPTY_EN; | |
505 | } | |
506 | ||
507 | writel(HSI2C_SLV_ADDR_MAS(i2c->msg->addr), i2c->regs + HSI2C_ADDR); | |
508 | ||
509 | writel(fifo_ctl, i2c->regs + HSI2C_FIFO_CTL); | |
510 | writel(i2c_ctl, i2c->regs + HSI2C_CTL); | |
511 | ||
512 | ||
513 | /* | |
514 | * Enable interrupts before starting the transfer so that we don't | |
515 | * miss any INT_I2C interrupts. | |
516 | */ | |
517 | spin_lock_irqsave(&i2c->lock, flags); | |
518 | writel(int_en, i2c->regs + HSI2C_INT_ENABLE); | |
519 | ||
520 | if (stop == 1) | |
521 | i2c_auto_conf |= HSI2C_STOP_AFTER_TRANS; | |
522 | i2c_auto_conf |= i2c->msg->len; | |
523 | i2c_auto_conf |= HSI2C_MASTER_RUN; | |
524 | writel(i2c_auto_conf, i2c->regs + HSI2C_AUTO_CONF); | |
525 | spin_unlock_irqrestore(&i2c->lock, flags); | |
526 | } | |
527 | ||
528 | static int exynos5_i2c_xfer_msg(struct exynos5_i2c *i2c, | |
529 | struct i2c_msg *msgs, int stop) | |
530 | { | |
531 | unsigned long timeout; | |
532 | int ret; | |
533 | ||
534 | i2c->msg = msgs; | |
535 | i2c->msg_ptr = 0; | |
536 | i2c->trans_done = 0; | |
537 | ||
538 | INIT_COMPLETION(i2c->msg_complete); | |
539 | ||
540 | exynos5_i2c_message_start(i2c, stop); | |
541 | ||
542 | timeout = wait_for_completion_timeout(&i2c->msg_complete, | |
543 | EXYNOS5_I2C_TIMEOUT); | |
544 | if (timeout == 0) | |
545 | ret = -ETIMEDOUT; | |
546 | else | |
547 | ret = i2c->state; | |
548 | ||
549 | /* | |
550 | * If this is the last message to be transfered (stop == 1) | |
551 | * Then check if the bus can be brought back to idle. | |
552 | */ | |
553 | if (ret == 0 && stop) | |
554 | ret = exynos5_i2c_wait_bus_idle(i2c); | |
555 | ||
556 | if (ret < 0) { | |
557 | exynos5_i2c_reset(i2c); | |
558 | if (ret == -ETIMEDOUT) | |
559 | dev_warn(i2c->dev, "%s timeout\n", | |
560 | (msgs->flags & I2C_M_RD) ? "rx" : "tx"); | |
561 | } | |
562 | ||
563 | /* Return the state as in interrupt routine */ | |
564 | return ret; | |
565 | } | |
566 | ||
567 | static int exynos5_i2c_xfer(struct i2c_adapter *adap, | |
568 | struct i2c_msg *msgs, int num) | |
569 | { | |
570 | struct exynos5_i2c *i2c = (struct exynos5_i2c *)adap->algo_data; | |
571 | int i = 0, ret = 0, stop = 0; | |
572 | ||
573 | if (i2c->suspended) { | |
574 | dev_err(i2c->dev, "HS-I2C is not initialzed.\n"); | |
575 | return -EIO; | |
576 | } | |
577 | ||
578 | clk_prepare_enable(i2c->clk); | |
579 | ||
580 | for (i = 0; i < num; i++, msgs++) { | |
581 | stop = (i == num - 1); | |
582 | ||
583 | ret = exynos5_i2c_xfer_msg(i2c, msgs, stop); | |
584 | ||
585 | if (ret < 0) | |
586 | goto out; | |
587 | } | |
588 | ||
589 | if (i == num) { | |
590 | ret = num; | |
591 | } else { | |
592 | /* Only one message, cannot access the device */ | |
593 | if (i == 1) | |
594 | ret = -EREMOTEIO; | |
595 | else | |
596 | ret = i; | |
597 | ||
598 | dev_warn(i2c->dev, "xfer message failed\n"); | |
599 | } | |
600 | ||
601 | out: | |
602 | clk_disable_unprepare(i2c->clk); | |
603 | return ret; | |
604 | } | |
605 | ||
606 | static u32 exynos5_i2c_func(struct i2c_adapter *adap) | |
607 | { | |
608 | return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK); | |
609 | } | |
610 | ||
611 | static const struct i2c_algorithm exynos5_i2c_algorithm = { | |
612 | .master_xfer = exynos5_i2c_xfer, | |
613 | .functionality = exynos5_i2c_func, | |
614 | }; | |
615 | ||
616 | static int exynos5_i2c_probe(struct platform_device *pdev) | |
617 | { | |
618 | struct device_node *np = pdev->dev.of_node; | |
619 | struct exynos5_i2c *i2c; | |
620 | struct resource *mem; | |
621 | unsigned int op_clock; | |
622 | int ret; | |
623 | ||
624 | i2c = devm_kzalloc(&pdev->dev, sizeof(struct exynos5_i2c), GFP_KERNEL); | |
625 | if (!i2c) { | |
626 | dev_err(&pdev->dev, "no memory for state\n"); | |
627 | return -ENOMEM; | |
628 | } | |
629 | ||
630 | if (of_property_read_u32(np, "clock-frequency", &op_clock)) { | |
631 | i2c->speed_mode = HSI2C_FAST_SPD; | |
632 | i2c->fs_clock = HSI2C_FS_TX_CLOCK; | |
633 | } else { | |
634 | if (op_clock >= HSI2C_HS_TX_CLOCK) { | |
635 | i2c->speed_mode = HSI2C_HIGH_SPD; | |
636 | i2c->fs_clock = HSI2C_FS_TX_CLOCK; | |
637 | i2c->hs_clock = op_clock; | |
638 | } else { | |
639 | i2c->speed_mode = HSI2C_FAST_SPD; | |
640 | i2c->fs_clock = op_clock; | |
641 | } | |
642 | } | |
643 | ||
644 | strlcpy(i2c->adap.name, "exynos5-i2c", sizeof(i2c->adap.name)); | |
645 | i2c->adap.owner = THIS_MODULE; | |
646 | i2c->adap.algo = &exynos5_i2c_algorithm; | |
647 | i2c->adap.retries = 3; | |
648 | ||
649 | i2c->dev = &pdev->dev; | |
650 | i2c->clk = devm_clk_get(&pdev->dev, "hsi2c"); | |
651 | if (IS_ERR(i2c->clk)) { | |
652 | dev_err(&pdev->dev, "cannot get clock\n"); | |
653 | return -ENOENT; | |
654 | } | |
655 | ||
656 | clk_prepare_enable(i2c->clk); | |
657 | ||
658 | mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
659 | i2c->regs = devm_ioremap_resource(&pdev->dev, mem); | |
660 | if (IS_ERR(i2c->regs)) { | |
661 | ret = PTR_ERR(i2c->regs); | |
662 | goto err_clk; | |
663 | } | |
664 | ||
665 | i2c->adap.dev.of_node = np; | |
666 | i2c->adap.algo_data = i2c; | |
667 | i2c->adap.dev.parent = &pdev->dev; | |
668 | ||
669 | /* Clear pending interrupts from u-boot or misc causes */ | |
670 | exynos5_i2c_clr_pend_irq(i2c); | |
671 | ||
672 | spin_lock_init(&i2c->lock); | |
673 | init_completion(&i2c->msg_complete); | |
674 | ||
675 | i2c->irq = ret = platform_get_irq(pdev, 0); | |
676 | if (ret <= 0) { | |
677 | dev_err(&pdev->dev, "cannot find HS-I2C IRQ\n"); | |
678 | ret = -EINVAL; | |
679 | goto err_clk; | |
680 | } | |
681 | ||
682 | ret = devm_request_irq(&pdev->dev, i2c->irq, exynos5_i2c_irq, | |
683 | IRQF_NO_SUSPEND | IRQF_ONESHOT, | |
684 | dev_name(&pdev->dev), i2c); | |
685 | ||
686 | if (ret != 0) { | |
687 | dev_err(&pdev->dev, "cannot request HS-I2C IRQ %d\n", i2c->irq); | |
688 | goto err_clk; | |
689 | } | |
690 | ||
691 | ret = exynos5_hsi2c_clock_setup(i2c); | |
692 | if (ret) | |
693 | goto err_clk; | |
694 | ||
695 | exynos5_i2c_init(i2c); | |
696 | ||
697 | ret = i2c_add_adapter(&i2c->adap); | |
698 | if (ret < 0) { | |
699 | dev_err(&pdev->dev, "failed to add bus to i2c core\n"); | |
700 | goto err_clk; | |
701 | } | |
702 | ||
703 | platform_set_drvdata(pdev, i2c); | |
704 | ||
8a73cd4c NKC |
705 | err_clk: |
706 | clk_disable_unprepare(i2c->clk); | |
707 | return ret; | |
708 | } | |
709 | ||
710 | static int exynos5_i2c_remove(struct platform_device *pdev) | |
711 | { | |
712 | struct exynos5_i2c *i2c = platform_get_drvdata(pdev); | |
713 | ||
714 | i2c_del_adapter(&i2c->adap); | |
8a73cd4c NKC |
715 | |
716 | return 0; | |
717 | } | |
718 | ||
719 | static int exynos5_i2c_suspend_noirq(struct device *dev) | |
720 | { | |
721 | struct platform_device *pdev = to_platform_device(dev); | |
722 | struct exynos5_i2c *i2c = platform_get_drvdata(pdev); | |
723 | ||
724 | i2c->suspended = 1; | |
725 | ||
726 | return 0; | |
727 | } | |
728 | ||
729 | static int exynos5_i2c_resume_noirq(struct device *dev) | |
730 | { | |
731 | struct platform_device *pdev = to_platform_device(dev); | |
732 | struct exynos5_i2c *i2c = platform_get_drvdata(pdev); | |
733 | int ret = 0; | |
734 | ||
735 | clk_prepare_enable(i2c->clk); | |
736 | ||
737 | ret = exynos5_hsi2c_clock_setup(i2c); | |
738 | if (ret) { | |
739 | clk_disable_unprepare(i2c->clk); | |
740 | return ret; | |
741 | } | |
742 | ||
743 | exynos5_i2c_init(i2c); | |
744 | clk_disable_unprepare(i2c->clk); | |
745 | i2c->suspended = 0; | |
746 | ||
747 | return 0; | |
748 | } | |
749 | ||
750 | static SIMPLE_DEV_PM_OPS(exynos5_i2c_dev_pm_ops, exynos5_i2c_suspend_noirq, | |
751 | exynos5_i2c_resume_noirq); | |
752 | ||
753 | static struct platform_driver exynos5_i2c_driver = { | |
754 | .probe = exynos5_i2c_probe, | |
755 | .remove = exynos5_i2c_remove, | |
756 | .driver = { | |
757 | .owner = THIS_MODULE, | |
758 | .name = "exynos5-hsi2c", | |
759 | .pm = &exynos5_i2c_dev_pm_ops, | |
760 | .of_match_table = exynos5_i2c_match, | |
761 | }, | |
762 | }; | |
763 | ||
764 | module_platform_driver(exynos5_i2c_driver); | |
765 | ||
766 | MODULE_DESCRIPTION("Exynos5 HS-I2C Bus driver"); | |
767 | MODULE_AUTHOR("Naveen Krishna Chatradhi, <ch.naveen@samsung.com>"); | |
768 | MODULE_AUTHOR("Taekgyun Ko, <taeggyun.ko@samsung.com>"); | |
769 | MODULE_LICENSE("GPL v2"); |