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8a73cd4c NKC |
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> | |
8a73cd4c NKC |
15 | #include <linux/time.h> |
16 | #include <linux/interrupt.h> | |
17 | #include <linux/delay.h> | |
18 | #include <linux/errno.h> | |
19 | #include <linux/err.h> | |
20 | #include <linux/platform_device.h> | |
21 | #include <linux/clk.h> | |
22 | #include <linux/slab.h> | |
23 | #include <linux/io.h> | |
24 | #include <linux/of_address.h> | |
b371f866 | 25 | #include <linux/of_device.h> |
8a73cd4c NKC |
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 | ||
8a73cd4c NKC |
80 | /* I2C_TRAILING_CTL Register bits */ |
81 | #define HSI2C_TRAILING_COUNT (0xf) | |
82 | ||
83 | /* I2C_INT_EN Register bits */ | |
84 | #define HSI2C_INT_TX_ALMOSTEMPTY_EN (1u << 0) | |
85 | #define HSI2C_INT_RX_ALMOSTFULL_EN (1u << 1) | |
86 | #define HSI2C_INT_TRAILING_EN (1u << 6) | |
8a73cd4c NKC |
87 | |
88 | /* I2C_INT_STAT Register bits */ | |
89 | #define HSI2C_INT_TX_ALMOSTEMPTY (1u << 0) | |
90 | #define HSI2C_INT_RX_ALMOSTFULL (1u << 1) | |
91 | #define HSI2C_INT_TX_UNDERRUN (1u << 2) | |
92 | #define HSI2C_INT_TX_OVERRUN (1u << 3) | |
93 | #define HSI2C_INT_RX_UNDERRUN (1u << 4) | |
94 | #define HSI2C_INT_RX_OVERRUN (1u << 5) | |
95 | #define HSI2C_INT_TRAILING (1u << 6) | |
96 | #define HSI2C_INT_I2C (1u << 9) | |
97 | ||
2374a539 NKC |
98 | #define HSI2C_INT_TRANS_DONE (1u << 7) |
99 | #define HSI2C_INT_TRANS_ABORT (1u << 8) | |
100 | #define HSI2C_INT_NO_DEV_ACK (1u << 9) | |
101 | #define HSI2C_INT_NO_DEV (1u << 10) | |
102 | #define HSI2C_INT_TIMEOUT (1u << 11) | |
103 | #define HSI2C_INT_I2C_TRANS (HSI2C_INT_TRANS_DONE | \ | |
104 | HSI2C_INT_TRANS_ABORT | \ | |
105 | HSI2C_INT_NO_DEV_ACK | \ | |
106 | HSI2C_INT_NO_DEV | \ | |
107 | HSI2C_INT_TIMEOUT) | |
108 | ||
8a73cd4c NKC |
109 | /* I2C_FIFO_STAT Register bits */ |
110 | #define HSI2C_RX_FIFO_EMPTY (1u << 24) | |
111 | #define HSI2C_RX_FIFO_FULL (1u << 23) | |
112 | #define HSI2C_RX_FIFO_LVL(x) ((x >> 16) & 0x7f) | |
113 | #define HSI2C_TX_FIFO_EMPTY (1u << 8) | |
114 | #define HSI2C_TX_FIFO_FULL (1u << 7) | |
115 | #define HSI2C_TX_FIFO_LVL(x) ((x >> 0) & 0x7f) | |
116 | ||
117 | /* I2C_CONF Register bits */ | |
118 | #define HSI2C_AUTO_MODE (1u << 31) | |
119 | #define HSI2C_10BIT_ADDR_MODE (1u << 30) | |
120 | #define HSI2C_HS_MODE (1u << 29) | |
121 | ||
122 | /* I2C_AUTO_CONF Register bits */ | |
123 | #define HSI2C_READ_WRITE (1u << 16) | |
124 | #define HSI2C_STOP_AFTER_TRANS (1u << 17) | |
125 | #define HSI2C_MASTER_RUN (1u << 31) | |
126 | ||
127 | /* I2C_TIMEOUT Register bits */ | |
128 | #define HSI2C_TIMEOUT_EN (1u << 31) | |
129 | #define HSI2C_TIMEOUT_MASK 0xff | |
130 | ||
131 | /* I2C_TRANS_STATUS register bits */ | |
132 | #define HSI2C_MASTER_BUSY (1u << 17) | |
133 | #define HSI2C_SLAVE_BUSY (1u << 16) | |
7999eecb AH |
134 | |
135 | /* I2C_TRANS_STATUS register bits for Exynos5 variant */ | |
8a73cd4c NKC |
136 | #define HSI2C_TIMEOUT_AUTO (1u << 4) |
137 | #define HSI2C_NO_DEV (1u << 3) | |
138 | #define HSI2C_NO_DEV_ACK (1u << 2) | |
139 | #define HSI2C_TRANS_ABORT (1u << 1) | |
140 | #define HSI2C_TRANS_DONE (1u << 0) | |
141 | ||
7999eecb AH |
142 | /* I2C_TRANS_STATUS register bits for Exynos7 variant */ |
143 | #define HSI2C_MASTER_ST_MASK 0xf | |
144 | #define HSI2C_MASTER_ST_IDLE 0x0 | |
145 | #define HSI2C_MASTER_ST_START 0x1 | |
146 | #define HSI2C_MASTER_ST_RESTART 0x2 | |
147 | #define HSI2C_MASTER_ST_STOP 0x3 | |
148 | #define HSI2C_MASTER_ST_MASTER_ID 0x4 | |
149 | #define HSI2C_MASTER_ST_ADDR0 0x5 | |
150 | #define HSI2C_MASTER_ST_ADDR1 0x6 | |
151 | #define HSI2C_MASTER_ST_ADDR2 0x7 | |
152 | #define HSI2C_MASTER_ST_ADDR_SR 0x8 | |
153 | #define HSI2C_MASTER_ST_READ 0x9 | |
154 | #define HSI2C_MASTER_ST_WRITE 0xa | |
155 | #define HSI2C_MASTER_ST_NO_ACK 0xb | |
156 | #define HSI2C_MASTER_ST_LOSE 0xc | |
157 | #define HSI2C_MASTER_ST_WAIT 0xd | |
158 | #define HSI2C_MASTER_ST_WAIT_CMD 0xe | |
159 | ||
8a73cd4c NKC |
160 | /* I2C_ADDR register bits */ |
161 | #define HSI2C_SLV_ADDR_SLV(x) ((x & 0x3ff) << 0) | |
162 | #define HSI2C_SLV_ADDR_MAS(x) ((x & 0x3ff) << 10) | |
163 | #define HSI2C_MASTER_ID(x) ((x & 0xff) << 24) | |
164 | #define MASTER_ID(x) ((x & 0x7) + 0x08) | |
165 | ||
166 | /* | |
167 | * Controller operating frequency, timing values for operation | |
168 | * are calculated against this frequency | |
169 | */ | |
170 | #define HSI2C_HS_TX_CLOCK 1000000 | |
171 | #define HSI2C_FS_TX_CLOCK 100000 | |
8a73cd4c NKC |
172 | |
173 | #define EXYNOS5_I2C_TIMEOUT (msecs_to_jiffies(1000)) | |
174 | ||
2374a539 NKC |
175 | #define HSI2C_EXYNOS7 BIT(0) |
176 | ||
8a73cd4c NKC |
177 | struct exynos5_i2c { |
178 | struct i2c_adapter adap; | |
179 | unsigned int suspended:1; | |
180 | ||
181 | struct i2c_msg *msg; | |
182 | struct completion msg_complete; | |
183 | unsigned int msg_ptr; | |
184 | ||
185 | unsigned int irq; | |
186 | ||
187 | void __iomem *regs; | |
188 | struct clk *clk; | |
189 | struct device *dev; | |
190 | int state; | |
191 | ||
192 | spinlock_t lock; /* IRQ synchronization */ | |
193 | ||
194 | /* | |
195 | * Since the TRANS_DONE bit is cleared on read, and we may read it | |
196 | * either during an IRQ or after a transaction, keep track of its | |
197 | * state here. | |
198 | */ | |
199 | int trans_done; | |
200 | ||
201 | /* Controller operating frequency */ | |
b9d5b31a | 202 | unsigned int op_clock; |
218e1496 NKC |
203 | |
204 | /* Version of HS-I2C Hardware */ | |
b371f866 | 205 | const struct exynos_hsi2c_variant *variant; |
218e1496 NKC |
206 | }; |
207 | ||
208 | /** | |
209 | * struct exynos_hsi2c_variant - platform specific HSI2C driver data | |
210 | * @fifo_depth: the fifo depth supported by the HSI2C module | |
211 | * | |
212 | * Specifies platform specific configuration of HSI2C module. | |
213 | * Note: A structure for driver specific platform data is used for future | |
214 | * expansion of its usage. | |
215 | */ | |
216 | struct exynos_hsi2c_variant { | |
217 | unsigned int fifo_depth; | |
2374a539 | 218 | unsigned int hw; |
218e1496 NKC |
219 | }; |
220 | ||
221 | static const struct exynos_hsi2c_variant exynos5250_hsi2c_data = { | |
222 | .fifo_depth = 64, | |
223 | }; | |
224 | ||
225 | static const struct exynos_hsi2c_variant exynos5260_hsi2c_data = { | |
226 | .fifo_depth = 16, | |
8a73cd4c NKC |
227 | }; |
228 | ||
2374a539 NKC |
229 | static const struct exynos_hsi2c_variant exynos7_hsi2c_data = { |
230 | .fifo_depth = 16, | |
231 | .hw = HSI2C_EXYNOS7, | |
232 | }; | |
233 | ||
8a73cd4c | 234 | static const struct of_device_id exynos5_i2c_match[] = { |
218e1496 NKC |
235 | { |
236 | .compatible = "samsung,exynos5-hsi2c", | |
237 | .data = &exynos5250_hsi2c_data | |
238 | }, { | |
239 | .compatible = "samsung,exynos5250-hsi2c", | |
240 | .data = &exynos5250_hsi2c_data | |
241 | }, { | |
242 | .compatible = "samsung,exynos5260-hsi2c", | |
243 | .data = &exynos5260_hsi2c_data | |
2374a539 NKC |
244 | }, { |
245 | .compatible = "samsung,exynos7-hsi2c", | |
246 | .data = &exynos7_hsi2c_data | |
218e1496 | 247 | }, {}, |
8a73cd4c NKC |
248 | }; |
249 | MODULE_DEVICE_TABLE(of, exynos5_i2c_match); | |
250 | ||
251 | static void exynos5_i2c_clr_pend_irq(struct exynos5_i2c *i2c) | |
252 | { | |
253 | writel(readl(i2c->regs + HSI2C_INT_STATUS), | |
254 | i2c->regs + HSI2C_INT_STATUS); | |
255 | } | |
256 | ||
257 | /* | |
258 | * exynos5_i2c_set_timing: updates the registers with appropriate | |
259 | * timing values calculated | |
260 | * | |
261 | * Returns 0 on success, -EINVAL if the cycle length cannot | |
262 | * be calculated. | |
263 | */ | |
b9d5b31a | 264 | static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, bool hs_timings) |
8a73cd4c NKC |
265 | { |
266 | u32 i2c_timing_s1; | |
267 | u32 i2c_timing_s2; | |
268 | u32 i2c_timing_s3; | |
269 | u32 i2c_timing_sla; | |
270 | unsigned int t_start_su, t_start_hd; | |
271 | unsigned int t_stop_su; | |
272 | unsigned int t_data_su, t_data_hd; | |
273 | unsigned int t_scl_l, t_scl_h; | |
274 | unsigned int t_sr_release; | |
275 | unsigned int t_ftl_cycle; | |
276 | unsigned int clkin = clk_get_rate(i2c->clk); | |
b9d5b31a AH |
277 | unsigned int op_clk = hs_timings ? i2c->op_clock : |
278 | (i2c->op_clock >= HSI2C_HS_TX_CLOCK) ? HSI2C_FS_TX_CLOCK : | |
279 | i2c->op_clock; | |
b917d4fd | 280 | int div, clk_cycle, temp; |
8a73cd4c NKC |
281 | |
282 | /* | |
2374a539 | 283 | * In case of HSI2C controller in Exynos5 series |
8a73cd4c NKC |
284 | * FPCLK / FI2C = |
285 | * (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) + 8 + 2 * FLT_CYCLE | |
2374a539 NKC |
286 | * |
287 | * In case of HSI2C controllers in Exynos7 series | |
288 | * FPCLK / FI2C = | |
289 | * (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) + 8 + FLT_CYCLE | |
290 | * | |
b917d4fd AH |
291 | * clk_cycle := TSCLK_L + TSCLK_H |
292 | * temp := (CLK_DIV + 1) * (clk_cycle + 2) | |
293 | * | |
294 | * Constraints: 4 <= temp, 0 <= CLK_DIV < 256, 2 <= clk_cycle <= 510 | |
295 | * | |
8a73cd4c NKC |
296 | */ |
297 | t_ftl_cycle = (readl(i2c->regs + HSI2C_CONF) >> 16) & 0x7; | |
b917d4fd AH |
298 | temp = clkin / op_clk - 8 - t_ftl_cycle; |
299 | if (i2c->variant->hw != HSI2C_EXYNOS7) | |
300 | temp -= t_ftl_cycle; | |
301 | div = temp / 512; | |
302 | clk_cycle = temp / (div + 1) - 2; | |
303 | if (temp < 4 || div >= 256 || clk_cycle < 2) { | |
70c8c4e9 AH |
304 | dev_err(i2c->dev, "%s clock set-up failed\n", |
305 | hs_timings ? "HS" : "FS"); | |
b917d4fd | 306 | return -EINVAL; |
8a73cd4c NKC |
307 | } |
308 | ||
309 | t_scl_l = clk_cycle / 2; | |
310 | t_scl_h = clk_cycle / 2; | |
311 | t_start_su = t_scl_l; | |
312 | t_start_hd = t_scl_l; | |
313 | t_stop_su = t_scl_l; | |
314 | t_data_su = t_scl_l / 2; | |
315 | t_data_hd = t_scl_l / 2; | |
316 | t_sr_release = clk_cycle; | |
317 | ||
318 | i2c_timing_s1 = t_start_su << 24 | t_start_hd << 16 | t_stop_su << 8; | |
319 | i2c_timing_s2 = t_data_su << 24 | t_scl_l << 8 | t_scl_h << 0; | |
320 | i2c_timing_s3 = div << 16 | t_sr_release << 0; | |
321 | i2c_timing_sla = t_data_hd << 0; | |
322 | ||
323 | dev_dbg(i2c->dev, "tSTART_SU: %X, tSTART_HD: %X, tSTOP_SU: %X\n", | |
324 | t_start_su, t_start_hd, t_stop_su); | |
325 | dev_dbg(i2c->dev, "tDATA_SU: %X, tSCL_L: %X, tSCL_H: %X\n", | |
326 | t_data_su, t_scl_l, t_scl_h); | |
327 | dev_dbg(i2c->dev, "nClkDiv: %X, tSR_RELEASE: %X\n", | |
328 | div, t_sr_release); | |
329 | dev_dbg(i2c->dev, "tDATA_HD: %X\n", t_data_hd); | |
330 | ||
b9d5b31a | 331 | if (hs_timings) { |
8a73cd4c NKC |
332 | writel(i2c_timing_s1, i2c->regs + HSI2C_TIMING_HS1); |
333 | writel(i2c_timing_s2, i2c->regs + HSI2C_TIMING_HS2); | |
334 | writel(i2c_timing_s3, i2c->regs + HSI2C_TIMING_HS3); | |
335 | } else { | |
336 | writel(i2c_timing_s1, i2c->regs + HSI2C_TIMING_FS1); | |
337 | writel(i2c_timing_s2, i2c->regs + HSI2C_TIMING_FS2); | |
338 | writel(i2c_timing_s3, i2c->regs + HSI2C_TIMING_FS3); | |
339 | } | |
340 | writel(i2c_timing_sla, i2c->regs + HSI2C_TIMING_SLA); | |
341 | ||
342 | return 0; | |
343 | } | |
344 | ||
345 | static int exynos5_hsi2c_clock_setup(struct exynos5_i2c *i2c) | |
346 | { | |
70c8c4e9 AH |
347 | /* always set Fast Speed timings */ |
348 | int ret = exynos5_i2c_set_timing(i2c, false); | |
8a73cd4c | 349 | |
70c8c4e9 AH |
350 | if (ret < 0 || i2c->op_clock < HSI2C_HS_TX_CLOCK) |
351 | return ret; | |
8a73cd4c | 352 | |
70c8c4e9 | 353 | return exynos5_i2c_set_timing(i2c, true); |
8a73cd4c NKC |
354 | } |
355 | ||
356 | /* | |
357 | * exynos5_i2c_init: configures the controller for I2C functionality | |
358 | * Programs I2C controller for Master mode operation | |
359 | */ | |
360 | static void exynos5_i2c_init(struct exynos5_i2c *i2c) | |
361 | { | |
362 | u32 i2c_conf = readl(i2c->regs + HSI2C_CONF); | |
363 | u32 i2c_timeout = readl(i2c->regs + HSI2C_TIMEOUT); | |
364 | ||
365 | /* Clear to disable Timeout */ | |
366 | i2c_timeout &= ~HSI2C_TIMEOUT_EN; | |
367 | writel(i2c_timeout, i2c->regs + HSI2C_TIMEOUT); | |
368 | ||
369 | writel((HSI2C_FUNC_MODE_I2C | HSI2C_MASTER), | |
370 | i2c->regs + HSI2C_CTL); | |
371 | writel(HSI2C_TRAILING_COUNT, i2c->regs + HSI2C_TRAILIG_CTL); | |
372 | ||
b9d5b31a | 373 | if (i2c->op_clock >= HSI2C_HS_TX_CLOCK) { |
8a73cd4c NKC |
374 | writel(HSI2C_MASTER_ID(MASTER_ID(i2c->adap.nr)), |
375 | i2c->regs + HSI2C_ADDR); | |
376 | i2c_conf |= HSI2C_HS_MODE; | |
377 | } | |
378 | ||
379 | writel(i2c_conf | HSI2C_AUTO_MODE, i2c->regs + HSI2C_CONF); | |
380 | } | |
381 | ||
382 | static void exynos5_i2c_reset(struct exynos5_i2c *i2c) | |
383 | { | |
384 | u32 i2c_ctl; | |
385 | ||
386 | /* Set and clear the bit for reset */ | |
387 | i2c_ctl = readl(i2c->regs + HSI2C_CTL); | |
388 | i2c_ctl |= HSI2C_SW_RST; | |
389 | writel(i2c_ctl, i2c->regs + HSI2C_CTL); | |
390 | ||
391 | i2c_ctl = readl(i2c->regs + HSI2C_CTL); | |
392 | i2c_ctl &= ~HSI2C_SW_RST; | |
393 | writel(i2c_ctl, i2c->regs + HSI2C_CTL); | |
394 | ||
395 | /* We don't expect calculations to fail during the run */ | |
396 | exynos5_hsi2c_clock_setup(i2c); | |
397 | /* Initialize the configure registers */ | |
398 | exynos5_i2c_init(i2c); | |
399 | } | |
400 | ||
401 | /* | |
402 | * exynos5_i2c_irq: top level IRQ servicing routine | |
403 | * | |
404 | * INT_STATUS registers gives the interrupt details. Further, | |
405 | * FIFO_STATUS or TRANS_STATUS registers are to be check for detailed | |
406 | * state of the bus. | |
407 | */ | |
408 | static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id) | |
409 | { | |
410 | struct exynos5_i2c *i2c = dev_id; | |
411 | u32 fifo_level, int_status, fifo_status, trans_status; | |
412 | unsigned char byte; | |
413 | int len = 0; | |
414 | ||
415 | i2c->state = -EINVAL; | |
416 | ||
417 | spin_lock(&i2c->lock); | |
418 | ||
419 | int_status = readl(i2c->regs + HSI2C_INT_STATUS); | |
420 | writel(int_status, i2c->regs + HSI2C_INT_STATUS); | |
8a73cd4c NKC |
421 | |
422 | /* handle interrupt related to the transfer status */ | |
2374a539 NKC |
423 | if (i2c->variant->hw == HSI2C_EXYNOS7) { |
424 | if (int_status & HSI2C_INT_TRANS_DONE) { | |
425 | i2c->trans_done = 1; | |
426 | i2c->state = 0; | |
427 | } else if (int_status & HSI2C_INT_TRANS_ABORT) { | |
428 | dev_dbg(i2c->dev, "Deal with arbitration lose\n"); | |
429 | i2c->state = -EAGAIN; | |
430 | goto stop; | |
431 | } else if (int_status & HSI2C_INT_NO_DEV_ACK) { | |
432 | dev_dbg(i2c->dev, "No ACK from device\n"); | |
433 | i2c->state = -ENXIO; | |
434 | goto stop; | |
435 | } else if (int_status & HSI2C_INT_NO_DEV) { | |
436 | dev_dbg(i2c->dev, "No device\n"); | |
437 | i2c->state = -ENXIO; | |
438 | goto stop; | |
439 | } else if (int_status & HSI2C_INT_TIMEOUT) { | |
440 | dev_dbg(i2c->dev, "Accessing device timed out\n"); | |
194fa7ff | 441 | i2c->state = -ETIMEDOUT; |
2374a539 NKC |
442 | goto stop; |
443 | } | |
7999eecb | 444 | |
9ad22474 | 445 | trans_status = readl(i2c->regs + HSI2C_TRANS_STATUS); |
7999eecb AH |
446 | if ((trans_status & HSI2C_MASTER_ST_MASK) == HSI2C_MASTER_ST_LOSE) { |
447 | i2c->state = -EAGAIN; | |
448 | goto stop; | |
449 | } | |
2374a539 | 450 | } else if (int_status & HSI2C_INT_I2C) { |
9ad22474 | 451 | trans_status = readl(i2c->regs + HSI2C_TRANS_STATUS); |
8a73cd4c NKC |
452 | if (trans_status & HSI2C_NO_DEV_ACK) { |
453 | dev_dbg(i2c->dev, "No ACK from device\n"); | |
454 | i2c->state = -ENXIO; | |
455 | goto stop; | |
456 | } else if (trans_status & HSI2C_NO_DEV) { | |
457 | dev_dbg(i2c->dev, "No device\n"); | |
458 | i2c->state = -ENXIO; | |
459 | goto stop; | |
460 | } else if (trans_status & HSI2C_TRANS_ABORT) { | |
461 | dev_dbg(i2c->dev, "Deal with arbitration lose\n"); | |
462 | i2c->state = -EAGAIN; | |
463 | goto stop; | |
464 | } else if (trans_status & HSI2C_TIMEOUT_AUTO) { | |
465 | dev_dbg(i2c->dev, "Accessing device timed out\n"); | |
194fa7ff | 466 | i2c->state = -ETIMEDOUT; |
8a73cd4c NKC |
467 | goto stop; |
468 | } else if (trans_status & HSI2C_TRANS_DONE) { | |
469 | i2c->trans_done = 1; | |
470 | i2c->state = 0; | |
471 | } | |
472 | } | |
473 | ||
474 | if ((i2c->msg->flags & I2C_M_RD) && (int_status & | |
475 | (HSI2C_INT_TRAILING | HSI2C_INT_RX_ALMOSTFULL))) { | |
476 | fifo_status = readl(i2c->regs + HSI2C_FIFO_STATUS); | |
477 | fifo_level = HSI2C_RX_FIFO_LVL(fifo_status); | |
478 | len = min(fifo_level, i2c->msg->len - i2c->msg_ptr); | |
479 | ||
480 | while (len > 0) { | |
481 | byte = (unsigned char) | |
482 | readl(i2c->regs + HSI2C_RX_DATA); | |
483 | i2c->msg->buf[i2c->msg_ptr++] = byte; | |
484 | len--; | |
485 | } | |
486 | i2c->state = 0; | |
487 | } else if (int_status & HSI2C_INT_TX_ALMOSTEMPTY) { | |
488 | fifo_status = readl(i2c->regs + HSI2C_FIFO_STATUS); | |
489 | fifo_level = HSI2C_TX_FIFO_LVL(fifo_status); | |
490 | ||
218e1496 | 491 | len = i2c->variant->fifo_depth - fifo_level; |
fd1c9c85 AH |
492 | if (len > (i2c->msg->len - i2c->msg_ptr)) { |
493 | u32 int_en = readl(i2c->regs + HSI2C_INT_ENABLE); | |
494 | ||
495 | int_en &= ~HSI2C_INT_TX_ALMOSTEMPTY_EN; | |
496 | writel(int_en, i2c->regs + HSI2C_INT_ENABLE); | |
8a73cd4c | 497 | len = i2c->msg->len - i2c->msg_ptr; |
fd1c9c85 | 498 | } |
8a73cd4c NKC |
499 | |
500 | while (len > 0) { | |
501 | byte = i2c->msg->buf[i2c->msg_ptr++]; | |
502 | writel(byte, i2c->regs + HSI2C_TX_DATA); | |
503 | len--; | |
504 | } | |
505 | i2c->state = 0; | |
506 | } | |
507 | ||
508 | stop: | |
509 | if ((i2c->trans_done && (i2c->msg->len == i2c->msg_ptr)) || | |
510 | (i2c->state < 0)) { | |
511 | writel(0, i2c->regs + HSI2C_INT_ENABLE); | |
512 | exynos5_i2c_clr_pend_irq(i2c); | |
513 | complete(&i2c->msg_complete); | |
514 | } | |
515 | ||
516 | spin_unlock(&i2c->lock); | |
517 | ||
518 | return IRQ_HANDLED; | |
519 | } | |
520 | ||
521 | /* | |
522 | * exynos5_i2c_wait_bus_idle | |
523 | * | |
524 | * Wait for the bus to go idle, indicated by the MASTER_BUSY bit being | |
525 | * cleared. | |
526 | * | |
527 | * Returns -EBUSY if the bus cannot be bought to idle | |
528 | */ | |
529 | static int exynos5_i2c_wait_bus_idle(struct exynos5_i2c *i2c) | |
530 | { | |
531 | unsigned long stop_time; | |
532 | u32 trans_status; | |
533 | ||
534 | /* wait for 100 milli seconds for the bus to be idle */ | |
535 | stop_time = jiffies + msecs_to_jiffies(100) + 1; | |
536 | do { | |
537 | trans_status = readl(i2c->regs + HSI2C_TRANS_STATUS); | |
538 | if (!(trans_status & HSI2C_MASTER_BUSY)) | |
539 | return 0; | |
540 | ||
541 | usleep_range(50, 200); | |
542 | } while (time_before(jiffies, stop_time)); | |
543 | ||
544 | return -EBUSY; | |
545 | } | |
546 | ||
547 | /* | |
548 | * exynos5_i2c_message_start: Configures the bus and starts the xfer | |
549 | * i2c: struct exynos5_i2c pointer for the current bus | |
550 | * stop: Enables stop after transfer if set. Set for last transfer of | |
551 | * in the list of messages. | |
552 | * | |
553 | * Configures the bus for read/write function | |
554 | * Sets chip address to talk to, message length to be sent. | |
555 | * Enables appropriate interrupts and sends start xfer command. | |
556 | */ | |
557 | static void exynos5_i2c_message_start(struct exynos5_i2c *i2c, int stop) | |
558 | { | |
559 | u32 i2c_ctl; | |
2374a539 | 560 | u32 int_en = 0; |
8a73cd4c NKC |
561 | u32 i2c_auto_conf = 0; |
562 | u32 fifo_ctl; | |
563 | unsigned long flags; | |
218e1496 | 564 | unsigned short trig_lvl; |
8a73cd4c | 565 | |
2374a539 NKC |
566 | if (i2c->variant->hw == HSI2C_EXYNOS7) |
567 | int_en |= HSI2C_INT_I2C_TRANS; | |
568 | else | |
569 | int_en |= HSI2C_INT_I2C; | |
570 | ||
8a73cd4c NKC |
571 | i2c_ctl = readl(i2c->regs + HSI2C_CTL); |
572 | i2c_ctl &= ~(HSI2C_TXCHON | HSI2C_RXCHON); | |
573 | fifo_ctl = HSI2C_RXFIFO_EN | HSI2C_TXFIFO_EN; | |
574 | ||
575 | if (i2c->msg->flags & I2C_M_RD) { | |
576 | i2c_ctl |= HSI2C_RXCHON; | |
577 | ||
290025d9 | 578 | i2c_auto_conf |= HSI2C_READ_WRITE; |
8a73cd4c | 579 | |
218e1496 NKC |
580 | trig_lvl = (i2c->msg->len > i2c->variant->fifo_depth) ? |
581 | (i2c->variant->fifo_depth * 3 / 4) : i2c->msg->len; | |
582 | fifo_ctl |= HSI2C_RXFIFO_TRIGGER_LEVEL(trig_lvl); | |
583 | ||
8a73cd4c NKC |
584 | int_en |= (HSI2C_INT_RX_ALMOSTFULL_EN | |
585 | HSI2C_INT_TRAILING_EN); | |
586 | } else { | |
587 | i2c_ctl |= HSI2C_TXCHON; | |
588 | ||
218e1496 NKC |
589 | trig_lvl = (i2c->msg->len > i2c->variant->fifo_depth) ? |
590 | (i2c->variant->fifo_depth * 1 / 4) : i2c->msg->len; | |
591 | fifo_ctl |= HSI2C_TXFIFO_TRIGGER_LEVEL(trig_lvl); | |
592 | ||
8a73cd4c NKC |
593 | int_en |= HSI2C_INT_TX_ALMOSTEMPTY_EN; |
594 | } | |
595 | ||
596 | writel(HSI2C_SLV_ADDR_MAS(i2c->msg->addr), i2c->regs + HSI2C_ADDR); | |
597 | ||
598 | writel(fifo_ctl, i2c->regs + HSI2C_FIFO_CTL); | |
599 | writel(i2c_ctl, i2c->regs + HSI2C_CTL); | |
600 | ||
8a73cd4c NKC |
601 | /* |
602 | * Enable interrupts before starting the transfer so that we don't | |
603 | * miss any INT_I2C interrupts. | |
604 | */ | |
605 | spin_lock_irqsave(&i2c->lock, flags); | |
606 | writel(int_en, i2c->regs + HSI2C_INT_ENABLE); | |
607 | ||
608 | if (stop == 1) | |
609 | i2c_auto_conf |= HSI2C_STOP_AFTER_TRANS; | |
610 | i2c_auto_conf |= i2c->msg->len; | |
611 | i2c_auto_conf |= HSI2C_MASTER_RUN; | |
612 | writel(i2c_auto_conf, i2c->regs + HSI2C_AUTO_CONF); | |
613 | spin_unlock_irqrestore(&i2c->lock, flags); | |
614 | } | |
615 | ||
616 | static int exynos5_i2c_xfer_msg(struct exynos5_i2c *i2c, | |
617 | struct i2c_msg *msgs, int stop) | |
618 | { | |
619 | unsigned long timeout; | |
620 | int ret; | |
621 | ||
622 | i2c->msg = msgs; | |
623 | i2c->msg_ptr = 0; | |
624 | i2c->trans_done = 0; | |
625 | ||
13509c3a | 626 | reinit_completion(&i2c->msg_complete); |
8a73cd4c NKC |
627 | |
628 | exynos5_i2c_message_start(i2c, stop); | |
629 | ||
630 | timeout = wait_for_completion_timeout(&i2c->msg_complete, | |
631 | EXYNOS5_I2C_TIMEOUT); | |
632 | if (timeout == 0) | |
633 | ret = -ETIMEDOUT; | |
634 | else | |
635 | ret = i2c->state; | |
636 | ||
637 | /* | |
638 | * If this is the last message to be transfered (stop == 1) | |
639 | * Then check if the bus can be brought back to idle. | |
640 | */ | |
641 | if (ret == 0 && stop) | |
642 | ret = exynos5_i2c_wait_bus_idle(i2c); | |
643 | ||
644 | if (ret < 0) { | |
645 | exynos5_i2c_reset(i2c); | |
646 | if (ret == -ETIMEDOUT) | |
647 | dev_warn(i2c->dev, "%s timeout\n", | |
648 | (msgs->flags & I2C_M_RD) ? "rx" : "tx"); | |
649 | } | |
650 | ||
651 | /* Return the state as in interrupt routine */ | |
652 | return ret; | |
653 | } | |
654 | ||
655 | static int exynos5_i2c_xfer(struct i2c_adapter *adap, | |
656 | struct i2c_msg *msgs, int num) | |
657 | { | |
0ff83d2c | 658 | struct exynos5_i2c *i2c = adap->algo_data; |
8a73cd4c NKC |
659 | int i = 0, ret = 0, stop = 0; |
660 | ||
661 | if (i2c->suspended) { | |
77d84ff8 | 662 | dev_err(i2c->dev, "HS-I2C is not initialized.\n"); |
8a73cd4c NKC |
663 | return -EIO; |
664 | } | |
665 | ||
10ff4c52 JMC |
666 | ret = clk_enable(i2c->clk); |
667 | if (ret) | |
668 | return ret; | |
8a73cd4c NKC |
669 | |
670 | for (i = 0; i < num; i++, msgs++) { | |
671 | stop = (i == num - 1); | |
672 | ||
673 | ret = exynos5_i2c_xfer_msg(i2c, msgs, stop); | |
674 | ||
675 | if (ret < 0) | |
676 | goto out; | |
677 | } | |
678 | ||
679 | if (i == num) { | |
680 | ret = num; | |
681 | } else { | |
682 | /* Only one message, cannot access the device */ | |
683 | if (i == 1) | |
684 | ret = -EREMOTEIO; | |
685 | else | |
686 | ret = i; | |
687 | ||
688 | dev_warn(i2c->dev, "xfer message failed\n"); | |
689 | } | |
690 | ||
691 | out: | |
10ff4c52 | 692 | clk_disable(i2c->clk); |
8a73cd4c NKC |
693 | return ret; |
694 | } | |
695 | ||
696 | static u32 exynos5_i2c_func(struct i2c_adapter *adap) | |
697 | { | |
698 | return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK); | |
699 | } | |
700 | ||
701 | static const struct i2c_algorithm exynos5_i2c_algorithm = { | |
702 | .master_xfer = exynos5_i2c_xfer, | |
703 | .functionality = exynos5_i2c_func, | |
704 | }; | |
705 | ||
706 | static int exynos5_i2c_probe(struct platform_device *pdev) | |
707 | { | |
708 | struct device_node *np = pdev->dev.of_node; | |
709 | struct exynos5_i2c *i2c; | |
710 | struct resource *mem; | |
8a73cd4c NKC |
711 | int ret; |
712 | ||
713 | i2c = devm_kzalloc(&pdev->dev, sizeof(struct exynos5_i2c), GFP_KERNEL); | |
46797a2a | 714 | if (!i2c) |
8a73cd4c | 715 | return -ENOMEM; |
8a73cd4c | 716 | |
b9d5b31a AH |
717 | if (of_property_read_u32(np, "clock-frequency", &i2c->op_clock)) |
718 | i2c->op_clock = HSI2C_FS_TX_CLOCK; | |
8a73cd4c NKC |
719 | |
720 | strlcpy(i2c->adap.name, "exynos5-i2c", sizeof(i2c->adap.name)); | |
721 | i2c->adap.owner = THIS_MODULE; | |
722 | i2c->adap.algo = &exynos5_i2c_algorithm; | |
723 | i2c->adap.retries = 3; | |
724 | ||
725 | i2c->dev = &pdev->dev; | |
726 | i2c->clk = devm_clk_get(&pdev->dev, "hsi2c"); | |
727 | if (IS_ERR(i2c->clk)) { | |
728 | dev_err(&pdev->dev, "cannot get clock\n"); | |
729 | return -ENOENT; | |
730 | } | |
731 | ||
10ff4c52 JMC |
732 | ret = clk_prepare_enable(i2c->clk); |
733 | if (ret) | |
734 | return ret; | |
8a73cd4c NKC |
735 | |
736 | mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
737 | i2c->regs = devm_ioremap_resource(&pdev->dev, mem); | |
738 | if (IS_ERR(i2c->regs)) { | |
739 | ret = PTR_ERR(i2c->regs); | |
740 | goto err_clk; | |
741 | } | |
742 | ||
743 | i2c->adap.dev.of_node = np; | |
744 | i2c->adap.algo_data = i2c; | |
745 | i2c->adap.dev.parent = &pdev->dev; | |
746 | ||
747 | /* Clear pending interrupts from u-boot or misc causes */ | |
748 | exynos5_i2c_clr_pend_irq(i2c); | |
749 | ||
750 | spin_lock_init(&i2c->lock); | |
751 | init_completion(&i2c->msg_complete); | |
752 | ||
753 | i2c->irq = ret = platform_get_irq(pdev, 0); | |
754 | if (ret <= 0) { | |
755 | dev_err(&pdev->dev, "cannot find HS-I2C IRQ\n"); | |
756 | ret = -EINVAL; | |
757 | goto err_clk; | |
758 | } | |
759 | ||
760 | ret = devm_request_irq(&pdev->dev, i2c->irq, exynos5_i2c_irq, | |
761 | IRQF_NO_SUSPEND | IRQF_ONESHOT, | |
762 | dev_name(&pdev->dev), i2c); | |
763 | ||
764 | if (ret != 0) { | |
765 | dev_err(&pdev->dev, "cannot request HS-I2C IRQ %d\n", i2c->irq); | |
766 | goto err_clk; | |
767 | } | |
768 | ||
b371f866 | 769 | i2c->variant = of_device_get_match_data(&pdev->dev); |
2374a539 | 770 | |
8a73cd4c NKC |
771 | ret = exynos5_hsi2c_clock_setup(i2c); |
772 | if (ret) | |
773 | goto err_clk; | |
774 | ||
218e1496 | 775 | exynos5_i2c_reset(i2c); |
8a73cd4c NKC |
776 | |
777 | ret = i2c_add_adapter(&i2c->adap); | |
ea734404 | 778 | if (ret < 0) |
8a73cd4c | 779 | goto err_clk; |
8a73cd4c NKC |
780 | |
781 | platform_set_drvdata(pdev, i2c); | |
782 | ||
10ff4c52 JMC |
783 | clk_disable(i2c->clk); |
784 | ||
785 | return 0; | |
786 | ||
8a73cd4c NKC |
787 | err_clk: |
788 | clk_disable_unprepare(i2c->clk); | |
789 | return ret; | |
790 | } | |
791 | ||
792 | static int exynos5_i2c_remove(struct platform_device *pdev) | |
793 | { | |
794 | struct exynos5_i2c *i2c = platform_get_drvdata(pdev); | |
795 | ||
796 | i2c_del_adapter(&i2c->adap); | |
8a73cd4c | 797 | |
10ff4c52 JMC |
798 | clk_unprepare(i2c->clk); |
799 | ||
8a73cd4c NKC |
800 | return 0; |
801 | } | |
802 | ||
3917b84d | 803 | #ifdef CONFIG_PM_SLEEP |
8a73cd4c NKC |
804 | static int exynos5_i2c_suspend_noirq(struct device *dev) |
805 | { | |
9242e72a | 806 | struct exynos5_i2c *i2c = dev_get_drvdata(dev); |
8a73cd4c NKC |
807 | |
808 | i2c->suspended = 1; | |
809 | ||
10ff4c52 JMC |
810 | clk_unprepare(i2c->clk); |
811 | ||
8a73cd4c NKC |
812 | return 0; |
813 | } | |
814 | ||
815 | static int exynos5_i2c_resume_noirq(struct device *dev) | |
816 | { | |
9242e72a | 817 | struct exynos5_i2c *i2c = dev_get_drvdata(dev); |
8a73cd4c NKC |
818 | int ret = 0; |
819 | ||
10ff4c52 JMC |
820 | ret = clk_prepare_enable(i2c->clk); |
821 | if (ret) | |
822 | return ret; | |
8a73cd4c NKC |
823 | |
824 | ret = exynos5_hsi2c_clock_setup(i2c); | |
825 | if (ret) { | |
826 | clk_disable_unprepare(i2c->clk); | |
827 | return ret; | |
828 | } | |
829 | ||
830 | exynos5_i2c_init(i2c); | |
10ff4c52 | 831 | clk_disable(i2c->clk); |
8a73cd4c NKC |
832 | i2c->suspended = 0; |
833 | ||
834 | return 0; | |
835 | } | |
3917b84d | 836 | #endif |
8a73cd4c | 837 | |
57186fe3 | 838 | static const struct dev_pm_ops exynos5_i2c_dev_pm_ops = { |
d4644bec AL |
839 | SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(exynos5_i2c_suspend_noirq, |
840 | exynos5_i2c_resume_noirq) | |
57186fe3 | 841 | }; |
8a73cd4c NKC |
842 | |
843 | static struct platform_driver exynos5_i2c_driver = { | |
844 | .probe = exynos5_i2c_probe, | |
845 | .remove = exynos5_i2c_remove, | |
846 | .driver = { | |
8a73cd4c NKC |
847 | .name = "exynos5-hsi2c", |
848 | .pm = &exynos5_i2c_dev_pm_ops, | |
849 | .of_match_table = exynos5_i2c_match, | |
850 | }, | |
851 | }; | |
852 | ||
853 | module_platform_driver(exynos5_i2c_driver); | |
854 | ||
855 | MODULE_DESCRIPTION("Exynos5 HS-I2C Bus driver"); | |
856 | MODULE_AUTHOR("Naveen Krishna Chatradhi, <ch.naveen@samsung.com>"); | |
857 | MODULE_AUTHOR("Taekgyun Ko, <taeggyun.ko@samsung.com>"); | |
858 | MODULE_LICENSE("GPL v2"); |