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Merge remote-tracking branches 'spi/topic/octeon', 'spi/topic/omap2-mcspi', 'spi...
[deliverable/linux.git] / drivers / i2c / busses / i2c-tegra.c
1 /*
2 * drivers/i2c/busses/i2c-tegra.c
3 *
4 * Copyright (C) 2010 Google, Inc.
5 * Author: Colin Cross <ccross@android.com>
6 *
7 * This software is licensed under the terms of the GNU General Public
8 * License version 2, as published by the Free Software Foundation, and
9 * may be copied, distributed, and modified under those terms.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 */
17
18 #include <linux/kernel.h>
19 #include <linux/init.h>
20 #include <linux/platform_device.h>
21 #include <linux/clk.h>
22 #include <linux/err.h>
23 #include <linux/i2c.h>
24 #include <linux/io.h>
25 #include <linux/interrupt.h>
26 #include <linux/delay.h>
27 #include <linux/slab.h>
28 #include <linux/of_device.h>
29 #include <linux/module.h>
30 #include <linux/reset.h>
31
32 #include <asm/unaligned.h>
33
34 #define TEGRA_I2C_TIMEOUT (msecs_to_jiffies(1000))
35 #define BYTES_PER_FIFO_WORD 4
36
37 #define I2C_CNFG 0x000
38 #define I2C_CNFG_DEBOUNCE_CNT_SHIFT 12
39 #define I2C_CNFG_PACKET_MODE_EN (1<<10)
40 #define I2C_CNFG_NEW_MASTER_FSM (1<<11)
41 #define I2C_STATUS 0x01C
42 #define I2C_SL_CNFG 0x020
43 #define I2C_SL_CNFG_NACK (1<<1)
44 #define I2C_SL_CNFG_NEWSL (1<<2)
45 #define I2C_SL_ADDR1 0x02c
46 #define I2C_SL_ADDR2 0x030
47 #define I2C_TX_FIFO 0x050
48 #define I2C_RX_FIFO 0x054
49 #define I2C_PACKET_TRANSFER_STATUS 0x058
50 #define I2C_FIFO_CONTROL 0x05c
51 #define I2C_FIFO_CONTROL_TX_FLUSH (1<<1)
52 #define I2C_FIFO_CONTROL_RX_FLUSH (1<<0)
53 #define I2C_FIFO_CONTROL_TX_TRIG_SHIFT 5
54 #define I2C_FIFO_CONTROL_RX_TRIG_SHIFT 2
55 #define I2C_FIFO_STATUS 0x060
56 #define I2C_FIFO_STATUS_TX_MASK 0xF0
57 #define I2C_FIFO_STATUS_TX_SHIFT 4
58 #define I2C_FIFO_STATUS_RX_MASK 0x0F
59 #define I2C_FIFO_STATUS_RX_SHIFT 0
60 #define I2C_INT_MASK 0x064
61 #define I2C_INT_STATUS 0x068
62 #define I2C_INT_PACKET_XFER_COMPLETE (1<<7)
63 #define I2C_INT_ALL_PACKETS_XFER_COMPLETE (1<<6)
64 #define I2C_INT_TX_FIFO_OVERFLOW (1<<5)
65 #define I2C_INT_RX_FIFO_UNDERFLOW (1<<4)
66 #define I2C_INT_NO_ACK (1<<3)
67 #define I2C_INT_ARBITRATION_LOST (1<<2)
68 #define I2C_INT_TX_FIFO_DATA_REQ (1<<1)
69 #define I2C_INT_RX_FIFO_DATA_REQ (1<<0)
70 #define I2C_CLK_DIVISOR 0x06c
71 #define I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT 16
72 #define I2C_CLK_MULTIPLIER_STD_FAST_MODE 8
73
74 #define DVC_CTRL_REG1 0x000
75 #define DVC_CTRL_REG1_INTR_EN (1<<10)
76 #define DVC_CTRL_REG2 0x004
77 #define DVC_CTRL_REG3 0x008
78 #define DVC_CTRL_REG3_SW_PROG (1<<26)
79 #define DVC_CTRL_REG3_I2C_DONE_INTR_EN (1<<30)
80 #define DVC_STATUS 0x00c
81 #define DVC_STATUS_I2C_DONE_INTR (1<<30)
82
83 #define I2C_ERR_NONE 0x00
84 #define I2C_ERR_NO_ACK 0x01
85 #define I2C_ERR_ARBITRATION_LOST 0x02
86 #define I2C_ERR_UNKNOWN_INTERRUPT 0x04
87
88 #define PACKET_HEADER0_HEADER_SIZE_SHIFT 28
89 #define PACKET_HEADER0_PACKET_ID_SHIFT 16
90 #define PACKET_HEADER0_CONT_ID_SHIFT 12
91 #define PACKET_HEADER0_PROTOCOL_I2C (1<<4)
92
93 #define I2C_HEADER_HIGHSPEED_MODE (1<<22)
94 #define I2C_HEADER_CONT_ON_NAK (1<<21)
95 #define I2C_HEADER_SEND_START_BYTE (1<<20)
96 #define I2C_HEADER_READ (1<<19)
97 #define I2C_HEADER_10BIT_ADDR (1<<18)
98 #define I2C_HEADER_IE_ENABLE (1<<17)
99 #define I2C_HEADER_REPEAT_START (1<<16)
100 #define I2C_HEADER_CONTINUE_XFER (1<<15)
101 #define I2C_HEADER_MASTER_ADDR_SHIFT 12
102 #define I2C_HEADER_SLAVE_ADDR_SHIFT 1
103
104 #define I2C_CONFIG_LOAD 0x08C
105 #define I2C_MSTR_CONFIG_LOAD (1 << 0)
106 #define I2C_SLV_CONFIG_LOAD (1 << 1)
107 #define I2C_TIMEOUT_CONFIG_LOAD (1 << 2)
108
109 /*
110 * msg_end_type: The bus control which need to be send at end of transfer.
111 * @MSG_END_STOP: Send stop pulse at end of transfer.
112 * @MSG_END_REPEAT_START: Send repeat start at end of transfer.
113 * @MSG_END_CONTINUE: The following on message is coming and so do not send
114 * stop or repeat start.
115 */
116 enum msg_end_type {
117 MSG_END_STOP,
118 MSG_END_REPEAT_START,
119 MSG_END_CONTINUE,
120 };
121
122 /**
123 * struct tegra_i2c_hw_feature : Different HW support on Tegra
124 * @has_continue_xfer_support: Continue transfer supports.
125 * @has_per_pkt_xfer_complete_irq: Has enable/disable capability for transfer
126 * complete interrupt per packet basis.
127 * @has_single_clk_source: The i2c controller has single clock source. Tegra30
128 * and earlier Socs has two clock sources i.e. div-clk and
129 * fast-clk.
130 * @has_config_load_reg: Has the config load register to load the new
131 * configuration.
132 * @clk_divisor_hs_mode: Clock divisor in HS mode.
133 * @clk_divisor_std_fast_mode: Clock divisor in standard/fast mode. It is
134 * applicable if there is no fast clock source i.e. single clock
135 * source.
136 */
137
138 struct tegra_i2c_hw_feature {
139 bool has_continue_xfer_support;
140 bool has_per_pkt_xfer_complete_irq;
141 bool has_single_clk_source;
142 bool has_config_load_reg;
143 int clk_divisor_hs_mode;
144 int clk_divisor_std_fast_mode;
145 u16 clk_divisor_fast_plus_mode;
146 };
147
148 /**
149 * struct tegra_i2c_dev - per device i2c context
150 * @dev: device reference for power management
151 * @hw: Tegra i2c hw feature.
152 * @adapter: core i2c layer adapter information
153 * @div_clk: clock reference for div clock of i2c controller.
154 * @fast_clk: clock reference for fast clock of i2c controller.
155 * @base: ioremapped registers cookie
156 * @cont_id: i2c controller id, used for for packet header
157 * @irq: irq number of transfer complete interrupt
158 * @is_dvc: identifies the DVC i2c controller, has a different register layout
159 * @msg_complete: transfer completion notifier
160 * @msg_err: error code for completed message
161 * @msg_buf: pointer to current message data
162 * @msg_buf_remaining: size of unsent data in the message buffer
163 * @msg_read: identifies read transfers
164 * @bus_clk_rate: current i2c bus clock rate
165 * @is_suspended: prevents i2c controller accesses after suspend is called
166 */
167 struct tegra_i2c_dev {
168 struct device *dev;
169 const struct tegra_i2c_hw_feature *hw;
170 struct i2c_adapter adapter;
171 struct clk *div_clk;
172 struct clk *fast_clk;
173 struct reset_control *rst;
174 void __iomem *base;
175 int cont_id;
176 int irq;
177 bool irq_disabled;
178 int is_dvc;
179 struct completion msg_complete;
180 int msg_err;
181 u8 *msg_buf;
182 size_t msg_buf_remaining;
183 int msg_read;
184 u32 bus_clk_rate;
185 u16 clk_divisor_non_hs_mode;
186 bool is_suspended;
187 };
188
189 static void dvc_writel(struct tegra_i2c_dev *i2c_dev, u32 val, unsigned long reg)
190 {
191 writel(val, i2c_dev->base + reg);
192 }
193
194 static u32 dvc_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
195 {
196 return readl(i2c_dev->base + reg);
197 }
198
199 /*
200 * i2c_writel and i2c_readl will offset the register if necessary to talk
201 * to the I2C block inside the DVC block
202 */
203 static unsigned long tegra_i2c_reg_addr(struct tegra_i2c_dev *i2c_dev,
204 unsigned long reg)
205 {
206 if (i2c_dev->is_dvc)
207 reg += (reg >= I2C_TX_FIFO) ? 0x10 : 0x40;
208 return reg;
209 }
210
211 static void i2c_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
212 unsigned long reg)
213 {
214 writel(val, i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
215
216 /* Read back register to make sure that register writes completed */
217 if (reg != I2C_TX_FIFO)
218 readl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
219 }
220
221 static u32 i2c_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
222 {
223 return readl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
224 }
225
226 static void i2c_writesl(struct tegra_i2c_dev *i2c_dev, void *data,
227 unsigned long reg, int len)
228 {
229 writesl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
230 }
231
232 static void i2c_readsl(struct tegra_i2c_dev *i2c_dev, void *data,
233 unsigned long reg, int len)
234 {
235 readsl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
236 }
237
238 static void tegra_i2c_mask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
239 {
240 u32 int_mask = i2c_readl(i2c_dev, I2C_INT_MASK);
241 int_mask &= ~mask;
242 i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
243 }
244
245 static void tegra_i2c_unmask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
246 {
247 u32 int_mask = i2c_readl(i2c_dev, I2C_INT_MASK);
248 int_mask |= mask;
249 i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
250 }
251
252 static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
253 {
254 unsigned long timeout = jiffies + HZ;
255 u32 val = i2c_readl(i2c_dev, I2C_FIFO_CONTROL);
256 val |= I2C_FIFO_CONTROL_TX_FLUSH | I2C_FIFO_CONTROL_RX_FLUSH;
257 i2c_writel(i2c_dev, val, I2C_FIFO_CONTROL);
258
259 while (i2c_readl(i2c_dev, I2C_FIFO_CONTROL) &
260 (I2C_FIFO_CONTROL_TX_FLUSH | I2C_FIFO_CONTROL_RX_FLUSH)) {
261 if (time_after(jiffies, timeout)) {
262 dev_warn(i2c_dev->dev, "timeout waiting for fifo flush\n");
263 return -ETIMEDOUT;
264 }
265 msleep(1);
266 }
267 return 0;
268 }
269
270 static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
271 {
272 u32 val;
273 int rx_fifo_avail;
274 u8 *buf = i2c_dev->msg_buf;
275 size_t buf_remaining = i2c_dev->msg_buf_remaining;
276 int words_to_transfer;
277
278 val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
279 rx_fifo_avail = (val & I2C_FIFO_STATUS_RX_MASK) >>
280 I2C_FIFO_STATUS_RX_SHIFT;
281
282 /* Rounds down to not include partial word at the end of buf */
283 words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
284 if (words_to_transfer > rx_fifo_avail)
285 words_to_transfer = rx_fifo_avail;
286
287 i2c_readsl(i2c_dev, buf, I2C_RX_FIFO, words_to_transfer);
288
289 buf += words_to_transfer * BYTES_PER_FIFO_WORD;
290 buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
291 rx_fifo_avail -= words_to_transfer;
292
293 /*
294 * If there is a partial word at the end of buf, handle it manually to
295 * prevent overwriting past the end of buf
296 */
297 if (rx_fifo_avail > 0 && buf_remaining > 0) {
298 BUG_ON(buf_remaining > 3);
299 val = i2c_readl(i2c_dev, I2C_RX_FIFO);
300 val = cpu_to_le32(val);
301 memcpy(buf, &val, buf_remaining);
302 buf_remaining = 0;
303 rx_fifo_avail--;
304 }
305
306 BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
307 i2c_dev->msg_buf_remaining = buf_remaining;
308 i2c_dev->msg_buf = buf;
309 return 0;
310 }
311
312 static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
313 {
314 u32 val;
315 int tx_fifo_avail;
316 u8 *buf = i2c_dev->msg_buf;
317 size_t buf_remaining = i2c_dev->msg_buf_remaining;
318 int words_to_transfer;
319
320 val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
321 tx_fifo_avail = (val & I2C_FIFO_STATUS_TX_MASK) >>
322 I2C_FIFO_STATUS_TX_SHIFT;
323
324 /* Rounds down to not include partial word at the end of buf */
325 words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
326
327 /* It's very common to have < 4 bytes, so optimize that case. */
328 if (words_to_transfer) {
329 if (words_to_transfer > tx_fifo_avail)
330 words_to_transfer = tx_fifo_avail;
331
332 /*
333 * Update state before writing to FIFO. If this casues us
334 * to finish writing all bytes (AKA buf_remaining goes to 0) we
335 * have a potential for an interrupt (PACKET_XFER_COMPLETE is
336 * not maskable). We need to make sure that the isr sees
337 * buf_remaining as 0 and doesn't call us back re-entrantly.
338 */
339 buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
340 tx_fifo_avail -= words_to_transfer;
341 i2c_dev->msg_buf_remaining = buf_remaining;
342 i2c_dev->msg_buf = buf +
343 words_to_transfer * BYTES_PER_FIFO_WORD;
344 barrier();
345
346 i2c_writesl(i2c_dev, buf, I2C_TX_FIFO, words_to_transfer);
347
348 buf += words_to_transfer * BYTES_PER_FIFO_WORD;
349 }
350
351 /*
352 * If there is a partial word at the end of buf, handle it manually to
353 * prevent reading past the end of buf, which could cross a page
354 * boundary and fault.
355 */
356 if (tx_fifo_avail > 0 && buf_remaining > 0) {
357 BUG_ON(buf_remaining > 3);
358 memcpy(&val, buf, buf_remaining);
359 val = le32_to_cpu(val);
360
361 /* Again update before writing to FIFO to make sure isr sees. */
362 i2c_dev->msg_buf_remaining = 0;
363 i2c_dev->msg_buf = NULL;
364 barrier();
365
366 i2c_writel(i2c_dev, val, I2C_TX_FIFO);
367 }
368
369 return 0;
370 }
371
372 /*
373 * One of the Tegra I2C blocks is inside the DVC (Digital Voltage Controller)
374 * block. This block is identical to the rest of the I2C blocks, except that
375 * it only supports master mode, it has registers moved around, and it needs
376 * some extra init to get it into I2C mode. The register moves are handled
377 * by i2c_readl and i2c_writel
378 */
379 static void tegra_dvc_init(struct tegra_i2c_dev *i2c_dev)
380 {
381 u32 val = 0;
382 val = dvc_readl(i2c_dev, DVC_CTRL_REG3);
383 val |= DVC_CTRL_REG3_SW_PROG;
384 val |= DVC_CTRL_REG3_I2C_DONE_INTR_EN;
385 dvc_writel(i2c_dev, val, DVC_CTRL_REG3);
386
387 val = dvc_readl(i2c_dev, DVC_CTRL_REG1);
388 val |= DVC_CTRL_REG1_INTR_EN;
389 dvc_writel(i2c_dev, val, DVC_CTRL_REG1);
390 }
391
392 static inline int tegra_i2c_clock_enable(struct tegra_i2c_dev *i2c_dev)
393 {
394 int ret;
395 if (!i2c_dev->hw->has_single_clk_source) {
396 ret = clk_enable(i2c_dev->fast_clk);
397 if (ret < 0) {
398 dev_err(i2c_dev->dev,
399 "Enabling fast clk failed, err %d\n", ret);
400 return ret;
401 }
402 }
403 ret = clk_enable(i2c_dev->div_clk);
404 if (ret < 0) {
405 dev_err(i2c_dev->dev,
406 "Enabling div clk failed, err %d\n", ret);
407 clk_disable(i2c_dev->fast_clk);
408 }
409 return ret;
410 }
411
412 static inline void tegra_i2c_clock_disable(struct tegra_i2c_dev *i2c_dev)
413 {
414 clk_disable(i2c_dev->div_clk);
415 if (!i2c_dev->hw->has_single_clk_source)
416 clk_disable(i2c_dev->fast_clk);
417 }
418
419 static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
420 {
421 u32 val;
422 int err = 0;
423 u32 clk_divisor;
424 unsigned long timeout = jiffies + HZ;
425
426 err = tegra_i2c_clock_enable(i2c_dev);
427 if (err < 0) {
428 dev_err(i2c_dev->dev, "Clock enable failed %d\n", err);
429 return err;
430 }
431
432 reset_control_assert(i2c_dev->rst);
433 udelay(2);
434 reset_control_deassert(i2c_dev->rst);
435
436 if (i2c_dev->is_dvc)
437 tegra_dvc_init(i2c_dev);
438
439 val = I2C_CNFG_NEW_MASTER_FSM | I2C_CNFG_PACKET_MODE_EN |
440 (0x2 << I2C_CNFG_DEBOUNCE_CNT_SHIFT);
441 i2c_writel(i2c_dev, val, I2C_CNFG);
442 i2c_writel(i2c_dev, 0, I2C_INT_MASK);
443
444 /* Make sure clock divisor programmed correctly */
445 clk_divisor = i2c_dev->hw->clk_divisor_hs_mode;
446 clk_divisor |= i2c_dev->clk_divisor_non_hs_mode <<
447 I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT;
448 i2c_writel(i2c_dev, clk_divisor, I2C_CLK_DIVISOR);
449
450 if (!i2c_dev->is_dvc) {
451 u32 sl_cfg = i2c_readl(i2c_dev, I2C_SL_CNFG);
452 sl_cfg |= I2C_SL_CNFG_NACK | I2C_SL_CNFG_NEWSL;
453 i2c_writel(i2c_dev, sl_cfg, I2C_SL_CNFG);
454 i2c_writel(i2c_dev, 0xfc, I2C_SL_ADDR1);
455 i2c_writel(i2c_dev, 0x00, I2C_SL_ADDR2);
456
457 }
458
459 val = 7 << I2C_FIFO_CONTROL_TX_TRIG_SHIFT |
460 0 << I2C_FIFO_CONTROL_RX_TRIG_SHIFT;
461 i2c_writel(i2c_dev, val, I2C_FIFO_CONTROL);
462
463 if (tegra_i2c_flush_fifos(i2c_dev))
464 err = -ETIMEDOUT;
465
466 if (i2c_dev->hw->has_config_load_reg) {
467 i2c_writel(i2c_dev, I2C_MSTR_CONFIG_LOAD, I2C_CONFIG_LOAD);
468 while (i2c_readl(i2c_dev, I2C_CONFIG_LOAD) != 0) {
469 if (time_after(jiffies, timeout)) {
470 dev_warn(i2c_dev->dev,
471 "timeout waiting for config load\n");
472 return -ETIMEDOUT;
473 }
474 msleep(1);
475 }
476 }
477
478 tegra_i2c_clock_disable(i2c_dev);
479
480 if (i2c_dev->irq_disabled) {
481 i2c_dev->irq_disabled = 0;
482 enable_irq(i2c_dev->irq);
483 }
484
485 return err;
486 }
487
488 static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
489 {
490 u32 status;
491 const u32 status_err = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
492 struct tegra_i2c_dev *i2c_dev = dev_id;
493
494 status = i2c_readl(i2c_dev, I2C_INT_STATUS);
495
496 if (status == 0) {
497 dev_warn(i2c_dev->dev, "irq status 0 %08x %08x %08x\n",
498 i2c_readl(i2c_dev, I2C_PACKET_TRANSFER_STATUS),
499 i2c_readl(i2c_dev, I2C_STATUS),
500 i2c_readl(i2c_dev, I2C_CNFG));
501 i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT;
502
503 if (!i2c_dev->irq_disabled) {
504 disable_irq_nosync(i2c_dev->irq);
505 i2c_dev->irq_disabled = 1;
506 }
507 goto err;
508 }
509
510 if (unlikely(status & status_err)) {
511 if (status & I2C_INT_NO_ACK)
512 i2c_dev->msg_err |= I2C_ERR_NO_ACK;
513 if (status & I2C_INT_ARBITRATION_LOST)
514 i2c_dev->msg_err |= I2C_ERR_ARBITRATION_LOST;
515 goto err;
516 }
517
518 if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) {
519 if (i2c_dev->msg_buf_remaining)
520 tegra_i2c_empty_rx_fifo(i2c_dev);
521 else
522 BUG();
523 }
524
525 if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
526 if (i2c_dev->msg_buf_remaining)
527 tegra_i2c_fill_tx_fifo(i2c_dev);
528 else
529 tegra_i2c_mask_irq(i2c_dev, I2C_INT_TX_FIFO_DATA_REQ);
530 }
531
532 i2c_writel(i2c_dev, status, I2C_INT_STATUS);
533 if (i2c_dev->is_dvc)
534 dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
535
536 if (status & I2C_INT_PACKET_XFER_COMPLETE) {
537 BUG_ON(i2c_dev->msg_buf_remaining);
538 complete(&i2c_dev->msg_complete);
539 }
540 return IRQ_HANDLED;
541 err:
542 /* An error occurred, mask all interrupts */
543 tegra_i2c_mask_irq(i2c_dev, I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST |
544 I2C_INT_PACKET_XFER_COMPLETE | I2C_INT_TX_FIFO_DATA_REQ |
545 I2C_INT_RX_FIFO_DATA_REQ);
546 i2c_writel(i2c_dev, status, I2C_INT_STATUS);
547 if (i2c_dev->is_dvc)
548 dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
549
550 complete(&i2c_dev->msg_complete);
551 return IRQ_HANDLED;
552 }
553
554 static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
555 struct i2c_msg *msg, enum msg_end_type end_state)
556 {
557 u32 packet_header;
558 u32 int_mask;
559 unsigned long time_left;
560
561 tegra_i2c_flush_fifos(i2c_dev);
562
563 if (msg->len == 0)
564 return -EINVAL;
565
566 i2c_dev->msg_buf = msg->buf;
567 i2c_dev->msg_buf_remaining = msg->len;
568 i2c_dev->msg_err = I2C_ERR_NONE;
569 i2c_dev->msg_read = (msg->flags & I2C_M_RD);
570 reinit_completion(&i2c_dev->msg_complete);
571
572 packet_header = (0 << PACKET_HEADER0_HEADER_SIZE_SHIFT) |
573 PACKET_HEADER0_PROTOCOL_I2C |
574 (i2c_dev->cont_id << PACKET_HEADER0_CONT_ID_SHIFT) |
575 (1 << PACKET_HEADER0_PACKET_ID_SHIFT);
576 i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
577
578 packet_header = msg->len - 1;
579 i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
580
581 packet_header = I2C_HEADER_IE_ENABLE;
582 if (end_state == MSG_END_CONTINUE)
583 packet_header |= I2C_HEADER_CONTINUE_XFER;
584 else if (end_state == MSG_END_REPEAT_START)
585 packet_header |= I2C_HEADER_REPEAT_START;
586 if (msg->flags & I2C_M_TEN) {
587 packet_header |= msg->addr;
588 packet_header |= I2C_HEADER_10BIT_ADDR;
589 } else {
590 packet_header |= msg->addr << I2C_HEADER_SLAVE_ADDR_SHIFT;
591 }
592 if (msg->flags & I2C_M_IGNORE_NAK)
593 packet_header |= I2C_HEADER_CONT_ON_NAK;
594 if (msg->flags & I2C_M_RD)
595 packet_header |= I2C_HEADER_READ;
596 i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
597
598 if (!(msg->flags & I2C_M_RD))
599 tegra_i2c_fill_tx_fifo(i2c_dev);
600
601 int_mask = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
602 if (i2c_dev->hw->has_per_pkt_xfer_complete_irq)
603 int_mask |= I2C_INT_PACKET_XFER_COMPLETE;
604 if (msg->flags & I2C_M_RD)
605 int_mask |= I2C_INT_RX_FIFO_DATA_REQ;
606 else if (i2c_dev->msg_buf_remaining)
607 int_mask |= I2C_INT_TX_FIFO_DATA_REQ;
608 tegra_i2c_unmask_irq(i2c_dev, int_mask);
609 dev_dbg(i2c_dev->dev, "unmasked irq: %02x\n",
610 i2c_readl(i2c_dev, I2C_INT_MASK));
611
612 time_left = wait_for_completion_timeout(&i2c_dev->msg_complete,
613 TEGRA_I2C_TIMEOUT);
614 tegra_i2c_mask_irq(i2c_dev, int_mask);
615
616 if (time_left == 0) {
617 dev_err(i2c_dev->dev, "i2c transfer timed out\n");
618
619 tegra_i2c_init(i2c_dev);
620 return -ETIMEDOUT;
621 }
622
623 dev_dbg(i2c_dev->dev, "transfer complete: %lu %d %d\n",
624 time_left, completion_done(&i2c_dev->msg_complete),
625 i2c_dev->msg_err);
626
627 if (likely(i2c_dev->msg_err == I2C_ERR_NONE))
628 return 0;
629
630 /*
631 * NACK interrupt is generated before the I2C controller generates the
632 * STOP condition on the bus. So wait for 2 clock periods before resetting
633 * the controller so that STOP condition has been delivered properly.
634 */
635 if (i2c_dev->msg_err == I2C_ERR_NO_ACK)
636 udelay(DIV_ROUND_UP(2 * 1000000, i2c_dev->bus_clk_rate));
637
638 tegra_i2c_init(i2c_dev);
639 if (i2c_dev->msg_err == I2C_ERR_NO_ACK) {
640 if (msg->flags & I2C_M_IGNORE_NAK)
641 return 0;
642 return -EREMOTEIO;
643 }
644
645 return -EIO;
646 }
647
648 static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
649 int num)
650 {
651 struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
652 int i;
653 int ret = 0;
654
655 if (i2c_dev->is_suspended)
656 return -EBUSY;
657
658 ret = tegra_i2c_clock_enable(i2c_dev);
659 if (ret < 0) {
660 dev_err(i2c_dev->dev, "Clock enable failed %d\n", ret);
661 return ret;
662 }
663
664 for (i = 0; i < num; i++) {
665 enum msg_end_type end_type = MSG_END_STOP;
666 if (i < (num - 1)) {
667 if (msgs[i + 1].flags & I2C_M_NOSTART)
668 end_type = MSG_END_CONTINUE;
669 else
670 end_type = MSG_END_REPEAT_START;
671 }
672 ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], end_type);
673 if (ret)
674 break;
675 }
676 tegra_i2c_clock_disable(i2c_dev);
677 return ret ?: i;
678 }
679
680 static u32 tegra_i2c_func(struct i2c_adapter *adap)
681 {
682 struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
683 u32 ret = I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
684 I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING;
685
686 if (i2c_dev->hw->has_continue_xfer_support)
687 ret |= I2C_FUNC_NOSTART;
688 return ret;
689 }
690
691 static const struct i2c_algorithm tegra_i2c_algo = {
692 .master_xfer = tegra_i2c_xfer,
693 .functionality = tegra_i2c_func,
694 };
695
696 /* payload size is only 12 bit */
697 static struct i2c_adapter_quirks tegra_i2c_quirks = {
698 .max_read_len = 4096,
699 .max_write_len = 4096,
700 };
701
702 static const struct tegra_i2c_hw_feature tegra20_i2c_hw = {
703 .has_continue_xfer_support = false,
704 .has_per_pkt_xfer_complete_irq = false,
705 .has_single_clk_source = false,
706 .clk_divisor_hs_mode = 3,
707 .clk_divisor_std_fast_mode = 0,
708 .clk_divisor_fast_plus_mode = 0,
709 .has_config_load_reg = false,
710 };
711
712 static const struct tegra_i2c_hw_feature tegra30_i2c_hw = {
713 .has_continue_xfer_support = true,
714 .has_per_pkt_xfer_complete_irq = false,
715 .has_single_clk_source = false,
716 .clk_divisor_hs_mode = 3,
717 .clk_divisor_std_fast_mode = 0,
718 .clk_divisor_fast_plus_mode = 0,
719 .has_config_load_reg = false,
720 };
721
722 static const struct tegra_i2c_hw_feature tegra114_i2c_hw = {
723 .has_continue_xfer_support = true,
724 .has_per_pkt_xfer_complete_irq = true,
725 .has_single_clk_source = true,
726 .clk_divisor_hs_mode = 1,
727 .clk_divisor_std_fast_mode = 0x19,
728 .clk_divisor_fast_plus_mode = 0x10,
729 .has_config_load_reg = false,
730 };
731
732 static const struct tegra_i2c_hw_feature tegra124_i2c_hw = {
733 .has_continue_xfer_support = true,
734 .has_per_pkt_xfer_complete_irq = true,
735 .has_single_clk_source = true,
736 .clk_divisor_hs_mode = 1,
737 .clk_divisor_std_fast_mode = 0x19,
738 .clk_divisor_fast_plus_mode = 0x10,
739 .has_config_load_reg = true,
740 };
741
742 /* Match table for of_platform binding */
743 static const struct of_device_id tegra_i2c_of_match[] = {
744 { .compatible = "nvidia,tegra124-i2c", .data = &tegra124_i2c_hw, },
745 { .compatible = "nvidia,tegra114-i2c", .data = &tegra114_i2c_hw, },
746 { .compatible = "nvidia,tegra30-i2c", .data = &tegra30_i2c_hw, },
747 { .compatible = "nvidia,tegra20-i2c", .data = &tegra20_i2c_hw, },
748 { .compatible = "nvidia,tegra20-i2c-dvc", .data = &tegra20_i2c_hw, },
749 {},
750 };
751 MODULE_DEVICE_TABLE(of, tegra_i2c_of_match);
752
753 static int tegra_i2c_probe(struct platform_device *pdev)
754 {
755 struct tegra_i2c_dev *i2c_dev;
756 struct resource *res;
757 struct clk *div_clk;
758 struct clk *fast_clk;
759 void __iomem *base;
760 int irq;
761 int ret = 0;
762 int clk_multiplier = I2C_CLK_MULTIPLIER_STD_FAST_MODE;
763
764 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
765 base = devm_ioremap_resource(&pdev->dev, res);
766 if (IS_ERR(base))
767 return PTR_ERR(base);
768
769 res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
770 if (!res) {
771 dev_err(&pdev->dev, "no irq resource\n");
772 return -EINVAL;
773 }
774 irq = res->start;
775
776 div_clk = devm_clk_get(&pdev->dev, "div-clk");
777 if (IS_ERR(div_clk)) {
778 dev_err(&pdev->dev, "missing controller clock");
779 return PTR_ERR(div_clk);
780 }
781
782 i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
783 if (!i2c_dev)
784 return -ENOMEM;
785
786 i2c_dev->base = base;
787 i2c_dev->div_clk = div_clk;
788 i2c_dev->adapter.algo = &tegra_i2c_algo;
789 i2c_dev->adapter.quirks = &tegra_i2c_quirks;
790 i2c_dev->irq = irq;
791 i2c_dev->cont_id = pdev->id;
792 i2c_dev->dev = &pdev->dev;
793
794 i2c_dev->rst = devm_reset_control_get(&pdev->dev, "i2c");
795 if (IS_ERR(i2c_dev->rst)) {
796 dev_err(&pdev->dev, "missing controller reset");
797 return PTR_ERR(i2c_dev->rst);
798 }
799
800 ret = of_property_read_u32(i2c_dev->dev->of_node, "clock-frequency",
801 &i2c_dev->bus_clk_rate);
802 if (ret)
803 i2c_dev->bus_clk_rate = 100000; /* default clock rate */
804
805 i2c_dev->hw = &tegra20_i2c_hw;
806
807 if (pdev->dev.of_node) {
808 i2c_dev->hw = of_device_get_match_data(&pdev->dev);
809 i2c_dev->is_dvc = of_device_is_compatible(pdev->dev.of_node,
810 "nvidia,tegra20-i2c-dvc");
811 } else if (pdev->id == 3) {
812 i2c_dev->is_dvc = 1;
813 }
814 init_completion(&i2c_dev->msg_complete);
815
816 if (!i2c_dev->hw->has_single_clk_source) {
817 fast_clk = devm_clk_get(&pdev->dev, "fast-clk");
818 if (IS_ERR(fast_clk)) {
819 dev_err(&pdev->dev, "missing fast clock");
820 return PTR_ERR(fast_clk);
821 }
822 i2c_dev->fast_clk = fast_clk;
823 }
824
825 platform_set_drvdata(pdev, i2c_dev);
826
827 if (!i2c_dev->hw->has_single_clk_source) {
828 ret = clk_prepare(i2c_dev->fast_clk);
829 if (ret < 0) {
830 dev_err(i2c_dev->dev, "Clock prepare failed %d\n", ret);
831 return ret;
832 }
833 }
834
835 i2c_dev->clk_divisor_non_hs_mode =
836 i2c_dev->hw->clk_divisor_std_fast_mode;
837 if (i2c_dev->hw->clk_divisor_fast_plus_mode &&
838 (i2c_dev->bus_clk_rate == 1000000))
839 i2c_dev->clk_divisor_non_hs_mode =
840 i2c_dev->hw->clk_divisor_fast_plus_mode;
841
842 clk_multiplier *= (i2c_dev->clk_divisor_non_hs_mode + 1);
843 ret = clk_set_rate(i2c_dev->div_clk,
844 i2c_dev->bus_clk_rate * clk_multiplier);
845 if (ret) {
846 dev_err(i2c_dev->dev, "Clock rate change failed %d\n", ret);
847 goto unprepare_fast_clk;
848 }
849
850 ret = clk_prepare(i2c_dev->div_clk);
851 if (ret < 0) {
852 dev_err(i2c_dev->dev, "Clock prepare failed %d\n", ret);
853 goto unprepare_fast_clk;
854 }
855
856 ret = tegra_i2c_init(i2c_dev);
857 if (ret) {
858 dev_err(&pdev->dev, "Failed to initialize i2c controller");
859 goto unprepare_div_clk;
860 }
861
862 ret = devm_request_irq(&pdev->dev, i2c_dev->irq,
863 tegra_i2c_isr, 0, dev_name(&pdev->dev), i2c_dev);
864 if (ret) {
865 dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq);
866 goto unprepare_div_clk;
867 }
868
869 i2c_set_adapdata(&i2c_dev->adapter, i2c_dev);
870 i2c_dev->adapter.owner = THIS_MODULE;
871 i2c_dev->adapter.class = I2C_CLASS_DEPRECATED;
872 strlcpy(i2c_dev->adapter.name, "Tegra I2C adapter",
873 sizeof(i2c_dev->adapter.name));
874 i2c_dev->adapter.dev.parent = &pdev->dev;
875 i2c_dev->adapter.nr = pdev->id;
876 i2c_dev->adapter.dev.of_node = pdev->dev.of_node;
877
878 ret = i2c_add_numbered_adapter(&i2c_dev->adapter);
879 if (ret) {
880 dev_err(&pdev->dev, "Failed to add I2C adapter\n");
881 goto unprepare_div_clk;
882 }
883
884 return 0;
885
886 unprepare_div_clk:
887 clk_unprepare(i2c_dev->div_clk);
888
889 unprepare_fast_clk:
890 if (!i2c_dev->hw->has_single_clk_source)
891 clk_unprepare(i2c_dev->fast_clk);
892
893 return ret;
894 }
895
896 static int tegra_i2c_remove(struct platform_device *pdev)
897 {
898 struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
899 i2c_del_adapter(&i2c_dev->adapter);
900
901 clk_unprepare(i2c_dev->div_clk);
902 if (!i2c_dev->hw->has_single_clk_source)
903 clk_unprepare(i2c_dev->fast_clk);
904
905 return 0;
906 }
907
908 #ifdef CONFIG_PM_SLEEP
909 static int tegra_i2c_suspend(struct device *dev)
910 {
911 struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
912
913 i2c_lock_adapter(&i2c_dev->adapter);
914 i2c_dev->is_suspended = true;
915 i2c_unlock_adapter(&i2c_dev->adapter);
916
917 return 0;
918 }
919
920 static int tegra_i2c_resume(struct device *dev)
921 {
922 struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
923 int ret;
924
925 i2c_lock_adapter(&i2c_dev->adapter);
926
927 ret = tegra_i2c_init(i2c_dev);
928
929 if (ret) {
930 i2c_unlock_adapter(&i2c_dev->adapter);
931 return ret;
932 }
933
934 i2c_dev->is_suspended = false;
935
936 i2c_unlock_adapter(&i2c_dev->adapter);
937
938 return 0;
939 }
940
941 static SIMPLE_DEV_PM_OPS(tegra_i2c_pm, tegra_i2c_suspend, tegra_i2c_resume);
942 #define TEGRA_I2C_PM (&tegra_i2c_pm)
943 #else
944 #define TEGRA_I2C_PM NULL
945 #endif
946
947 static struct platform_driver tegra_i2c_driver = {
948 .probe = tegra_i2c_probe,
949 .remove = tegra_i2c_remove,
950 .driver = {
951 .name = "tegra-i2c",
952 .of_match_table = tegra_i2c_of_match,
953 .pm = TEGRA_I2C_PM,
954 },
955 };
956
957 static int __init tegra_i2c_init_driver(void)
958 {
959 return platform_driver_register(&tegra_i2c_driver);
960 }
961
962 static void __exit tegra_i2c_exit_driver(void)
963 {
964 platform_driver_unregister(&tegra_i2c_driver);
965 }
966
967 subsys_initcall(tegra_i2c_init_driver);
968 module_exit(tegra_i2c_exit_driver);
969
970 MODULE_DESCRIPTION("nVidia Tegra2 I2C Bus Controller driver");
971 MODULE_AUTHOR("Colin Cross");
972 MODULE_LICENSE("GPL v2");
Linux kernel - Deliverables
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