blob: 3c94c4a81a554563daecc1d872f044886b09fb1b [file] [log] [blame]
Colin Crossdb811ca2011-02-20 17:14:21 -08001/*
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/i2c-tegra.h>
John Bonesio5c470f32011-06-22 09:16:56 -070029#include <linux/of_i2c.h>
Colin Crossdb811ca2011-02-20 17:14:21 -080030
31#include <asm/unaligned.h>
32
33#include <mach/clk.h>
34
35#define TEGRA_I2C_TIMEOUT (msecs_to_jiffies(1000))
36#define BYTES_PER_FIFO_WORD 4
37
38#define I2C_CNFG 0x000
Jay Cheng40abcf72011-04-25 15:32:27 -060039#define I2C_CNFG_DEBOUNCE_CNT_SHIFT 12
Colin Crossdb811ca2011-02-20 17:14:21 -080040#define I2C_CNFG_PACKET_MODE_EN (1<<10)
41#define I2C_CNFG_NEW_MASTER_FSM (1<<11)
Todd Poynorcb63c622011-04-25 15:32:25 -060042#define I2C_STATUS 0x01C
Colin Crossdb811ca2011-02-20 17:14:21 -080043#define I2C_SL_CNFG 0x020
Stephen Warren5afa9d32011-06-06 11:25:19 -060044#define I2C_SL_CNFG_NACK (1<<1)
Colin Crossdb811ca2011-02-20 17:14:21 -080045#define I2C_SL_CNFG_NEWSL (1<<2)
46#define I2C_SL_ADDR1 0x02c
Stephen Warren5afa9d32011-06-06 11:25:19 -060047#define I2C_SL_ADDR2 0x030
Colin Crossdb811ca2011-02-20 17:14:21 -080048#define I2C_TX_FIFO 0x050
49#define I2C_RX_FIFO 0x054
50#define I2C_PACKET_TRANSFER_STATUS 0x058
51#define I2C_FIFO_CONTROL 0x05c
52#define I2C_FIFO_CONTROL_TX_FLUSH (1<<1)
53#define I2C_FIFO_CONTROL_RX_FLUSH (1<<0)
54#define I2C_FIFO_CONTROL_TX_TRIG_SHIFT 5
55#define I2C_FIFO_CONTROL_RX_TRIG_SHIFT 2
56#define I2C_FIFO_STATUS 0x060
57#define I2C_FIFO_STATUS_TX_MASK 0xF0
58#define I2C_FIFO_STATUS_TX_SHIFT 4
59#define I2C_FIFO_STATUS_RX_MASK 0x0F
60#define I2C_FIFO_STATUS_RX_SHIFT 0
61#define I2C_INT_MASK 0x064
62#define I2C_INT_STATUS 0x068
63#define I2C_INT_PACKET_XFER_COMPLETE (1<<7)
64#define I2C_INT_ALL_PACKETS_XFER_COMPLETE (1<<6)
65#define I2C_INT_TX_FIFO_OVERFLOW (1<<5)
66#define I2C_INT_RX_FIFO_UNDERFLOW (1<<4)
67#define I2C_INT_NO_ACK (1<<3)
68#define I2C_INT_ARBITRATION_LOST (1<<2)
69#define I2C_INT_TX_FIFO_DATA_REQ (1<<1)
70#define I2C_INT_RX_FIFO_DATA_REQ (1<<0)
71#define I2C_CLK_DIVISOR 0x06c
72
73#define DVC_CTRL_REG1 0x000
74#define DVC_CTRL_REG1_INTR_EN (1<<10)
75#define DVC_CTRL_REG2 0x004
76#define DVC_CTRL_REG3 0x008
77#define DVC_CTRL_REG3_SW_PROG (1<<26)
78#define DVC_CTRL_REG3_I2C_DONE_INTR_EN (1<<30)
79#define DVC_STATUS 0x00c
80#define DVC_STATUS_I2C_DONE_INTR (1<<30)
81
82#define I2C_ERR_NONE 0x00
83#define I2C_ERR_NO_ACK 0x01
84#define I2C_ERR_ARBITRATION_LOST 0x02
Todd Poynorcb63c622011-04-25 15:32:25 -060085#define I2C_ERR_UNKNOWN_INTERRUPT 0x04
Colin Crossdb811ca2011-02-20 17:14:21 -080086
87#define PACKET_HEADER0_HEADER_SIZE_SHIFT 28
88#define PACKET_HEADER0_PACKET_ID_SHIFT 16
89#define PACKET_HEADER0_CONT_ID_SHIFT 12
90#define PACKET_HEADER0_PROTOCOL_I2C (1<<4)
91
92#define I2C_HEADER_HIGHSPEED_MODE (1<<22)
93#define I2C_HEADER_CONT_ON_NAK (1<<21)
94#define I2C_HEADER_SEND_START_BYTE (1<<20)
95#define I2C_HEADER_READ (1<<19)
96#define I2C_HEADER_10BIT_ADDR (1<<18)
97#define I2C_HEADER_IE_ENABLE (1<<17)
98#define I2C_HEADER_REPEAT_START (1<<16)
99#define I2C_HEADER_MASTER_ADDR_SHIFT 12
100#define I2C_HEADER_SLAVE_ADDR_SHIFT 1
101
102/**
103 * struct tegra_i2c_dev - per device i2c context
104 * @dev: device reference for power management
105 * @adapter: core i2c layer adapter information
106 * @clk: clock reference for i2c controller
107 * @i2c_clk: clock reference for i2c bus
108 * @iomem: memory resource for registers
109 * @base: ioremapped registers cookie
110 * @cont_id: i2c controller id, used for for packet header
111 * @irq: irq number of transfer complete interrupt
112 * @is_dvc: identifies the DVC i2c controller, has a different register layout
113 * @msg_complete: transfer completion notifier
114 * @msg_err: error code for completed message
115 * @msg_buf: pointer to current message data
116 * @msg_buf_remaining: size of unsent data in the message buffer
117 * @msg_read: identifies read transfers
118 * @bus_clk_rate: current i2c bus clock rate
119 * @is_suspended: prevents i2c controller accesses after suspend is called
120 */
121struct tegra_i2c_dev {
122 struct device *dev;
123 struct i2c_adapter adapter;
124 struct clk *clk;
125 struct clk *i2c_clk;
126 struct resource *iomem;
127 void __iomem *base;
128 int cont_id;
129 int irq;
Todd Poynorcb63c622011-04-25 15:32:25 -0600130 bool irq_disabled;
Colin Crossdb811ca2011-02-20 17:14:21 -0800131 int is_dvc;
132 struct completion msg_complete;
133 int msg_err;
134 u8 *msg_buf;
135 size_t msg_buf_remaining;
136 int msg_read;
137 unsigned long bus_clk_rate;
138 bool is_suspended;
139};
140
141static void dvc_writel(struct tegra_i2c_dev *i2c_dev, u32 val, unsigned long reg)
142{
143 writel(val, i2c_dev->base + reg);
144}
145
146static u32 dvc_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
147{
148 return readl(i2c_dev->base + reg);
149}
150
151/*
152 * i2c_writel and i2c_readl will offset the register if necessary to talk
153 * to the I2C block inside the DVC block
154 */
155static unsigned long tegra_i2c_reg_addr(struct tegra_i2c_dev *i2c_dev,
156 unsigned long reg)
157{
158 if (i2c_dev->is_dvc)
159 reg += (reg >= I2C_TX_FIFO) ? 0x10 : 0x40;
160 return reg;
161}
162
163static void i2c_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
164 unsigned long reg)
165{
166 writel(val, i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
167}
168
169static u32 i2c_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
170{
171 return readl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
172}
173
174static void i2c_writesl(struct tegra_i2c_dev *i2c_dev, void *data,
175 unsigned long reg, int len)
176{
177 writesl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
178}
179
180static void i2c_readsl(struct tegra_i2c_dev *i2c_dev, void *data,
181 unsigned long reg, int len)
182{
183 readsl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
184}
185
186static void tegra_i2c_mask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
187{
188 u32 int_mask = i2c_readl(i2c_dev, I2C_INT_MASK);
189 int_mask &= ~mask;
190 i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
191}
192
193static void tegra_i2c_unmask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
194{
195 u32 int_mask = i2c_readl(i2c_dev, I2C_INT_MASK);
196 int_mask |= mask;
197 i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
198}
199
200static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
201{
202 unsigned long timeout = jiffies + HZ;
203 u32 val = i2c_readl(i2c_dev, I2C_FIFO_CONTROL);
204 val |= I2C_FIFO_CONTROL_TX_FLUSH | I2C_FIFO_CONTROL_RX_FLUSH;
205 i2c_writel(i2c_dev, val, I2C_FIFO_CONTROL);
206
207 while (i2c_readl(i2c_dev, I2C_FIFO_CONTROL) &
208 (I2C_FIFO_CONTROL_TX_FLUSH | I2C_FIFO_CONTROL_RX_FLUSH)) {
209 if (time_after(jiffies, timeout)) {
210 dev_warn(i2c_dev->dev, "timeout waiting for fifo flush\n");
211 return -ETIMEDOUT;
212 }
213 msleep(1);
214 }
215 return 0;
216}
217
218static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
219{
220 u32 val;
221 int rx_fifo_avail;
222 u8 *buf = i2c_dev->msg_buf;
223 size_t buf_remaining = i2c_dev->msg_buf_remaining;
224 int words_to_transfer;
225
226 val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
227 rx_fifo_avail = (val & I2C_FIFO_STATUS_RX_MASK) >>
228 I2C_FIFO_STATUS_RX_SHIFT;
229
230 /* Rounds down to not include partial word at the end of buf */
231 words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
232 if (words_to_transfer > rx_fifo_avail)
233 words_to_transfer = rx_fifo_avail;
234
235 i2c_readsl(i2c_dev, buf, I2C_RX_FIFO, words_to_transfer);
236
237 buf += words_to_transfer * BYTES_PER_FIFO_WORD;
238 buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
239 rx_fifo_avail -= words_to_transfer;
240
241 /*
242 * If there is a partial word at the end of buf, handle it manually to
243 * prevent overwriting past the end of buf
244 */
245 if (rx_fifo_avail > 0 && buf_remaining > 0) {
246 BUG_ON(buf_remaining > 3);
247 val = i2c_readl(i2c_dev, I2C_RX_FIFO);
248 memcpy(buf, &val, buf_remaining);
249 buf_remaining = 0;
250 rx_fifo_avail--;
251 }
252
253 BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
254 i2c_dev->msg_buf_remaining = buf_remaining;
255 i2c_dev->msg_buf = buf;
256 return 0;
257}
258
259static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
260{
261 u32 val;
262 int tx_fifo_avail;
263 u8 *buf = i2c_dev->msg_buf;
264 size_t buf_remaining = i2c_dev->msg_buf_remaining;
265 int words_to_transfer;
266
267 val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
268 tx_fifo_avail = (val & I2C_FIFO_STATUS_TX_MASK) >>
269 I2C_FIFO_STATUS_TX_SHIFT;
270
271 /* Rounds down to not include partial word at the end of buf */
272 words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
Colin Crossdb811ca2011-02-20 17:14:21 -0800273
Doug Anderson96219c32011-08-30 11:46:10 -0600274 /* It's very common to have < 4 bytes, so optimize that case. */
275 if (words_to_transfer) {
276 if (words_to_transfer > tx_fifo_avail)
277 words_to_transfer = tx_fifo_avail;
Colin Crossdb811ca2011-02-20 17:14:21 -0800278
Doug Anderson96219c32011-08-30 11:46:10 -0600279 /*
280 * Update state before writing to FIFO. If this casues us
281 * to finish writing all bytes (AKA buf_remaining goes to 0) we
282 * have a potential for an interrupt (PACKET_XFER_COMPLETE is
283 * not maskable). We need to make sure that the isr sees
284 * buf_remaining as 0 and doesn't call us back re-entrantly.
285 */
286 buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
287 tx_fifo_avail -= words_to_transfer;
288 i2c_dev->msg_buf_remaining = buf_remaining;
289 i2c_dev->msg_buf = buf +
290 words_to_transfer * BYTES_PER_FIFO_WORD;
291 barrier();
292
293 i2c_writesl(i2c_dev, buf, I2C_TX_FIFO, words_to_transfer);
294
295 buf += words_to_transfer * BYTES_PER_FIFO_WORD;
296 }
Colin Crossdb811ca2011-02-20 17:14:21 -0800297
298 /*
299 * If there is a partial word at the end of buf, handle it manually to
300 * prevent reading past the end of buf, which could cross a page
301 * boundary and fault.
302 */
303 if (tx_fifo_avail > 0 && buf_remaining > 0) {
304 BUG_ON(buf_remaining > 3);
305 memcpy(&val, buf, buf_remaining);
Doug Anderson96219c32011-08-30 11:46:10 -0600306
307 /* Again update before writing to FIFO to make sure isr sees. */
308 i2c_dev->msg_buf_remaining = 0;
309 i2c_dev->msg_buf = NULL;
310 barrier();
311
Colin Crossdb811ca2011-02-20 17:14:21 -0800312 i2c_writel(i2c_dev, val, I2C_TX_FIFO);
Colin Crossdb811ca2011-02-20 17:14:21 -0800313 }
314
Colin Crossdb811ca2011-02-20 17:14:21 -0800315 return 0;
316}
317
318/*
319 * One of the Tegra I2C blocks is inside the DVC (Digital Voltage Controller)
320 * block. This block is identical to the rest of the I2C blocks, except that
321 * it only supports master mode, it has registers moved around, and it needs
322 * some extra init to get it into I2C mode. The register moves are handled
323 * by i2c_readl and i2c_writel
324 */
325static void tegra_dvc_init(struct tegra_i2c_dev *i2c_dev)
326{
327 u32 val = 0;
328 val = dvc_readl(i2c_dev, DVC_CTRL_REG3);
329 val |= DVC_CTRL_REG3_SW_PROG;
330 val |= DVC_CTRL_REG3_I2C_DONE_INTR_EN;
331 dvc_writel(i2c_dev, val, DVC_CTRL_REG3);
332
333 val = dvc_readl(i2c_dev, DVC_CTRL_REG1);
334 val |= DVC_CTRL_REG1_INTR_EN;
335 dvc_writel(i2c_dev, val, DVC_CTRL_REG1);
336}
337
338static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
339{
340 u32 val;
341 int err = 0;
342
343 clk_enable(i2c_dev->clk);
344
345 tegra_periph_reset_assert(i2c_dev->clk);
346 udelay(2);
347 tegra_periph_reset_deassert(i2c_dev->clk);
348
349 if (i2c_dev->is_dvc)
350 tegra_dvc_init(i2c_dev);
351
Jay Cheng40abcf72011-04-25 15:32:27 -0600352 val = I2C_CNFG_NEW_MASTER_FSM | I2C_CNFG_PACKET_MODE_EN |
353 (0x2 << I2C_CNFG_DEBOUNCE_CNT_SHIFT);
Colin Crossdb811ca2011-02-20 17:14:21 -0800354 i2c_writel(i2c_dev, val, I2C_CNFG);
355 i2c_writel(i2c_dev, 0, I2C_INT_MASK);
356 clk_set_rate(i2c_dev->clk, i2c_dev->bus_clk_rate * 8);
357
Kenneth Waters65a1a0a2011-04-25 12:29:54 -0600358 if (!i2c_dev->is_dvc) {
359 u32 sl_cfg = i2c_readl(i2c_dev, I2C_SL_CNFG);
Stephen Warren5afa9d32011-06-06 11:25:19 -0600360 sl_cfg |= I2C_SL_CNFG_NACK | I2C_SL_CNFG_NEWSL;
361 i2c_writel(i2c_dev, sl_cfg, I2C_SL_CNFG);
362 i2c_writel(i2c_dev, 0xfc, I2C_SL_ADDR1);
363 i2c_writel(i2c_dev, 0x00, I2C_SL_ADDR2);
364
Kenneth Waters65a1a0a2011-04-25 12:29:54 -0600365 }
366
Colin Crossdb811ca2011-02-20 17:14:21 -0800367 val = 7 << I2C_FIFO_CONTROL_TX_TRIG_SHIFT |
368 0 << I2C_FIFO_CONTROL_RX_TRIG_SHIFT;
369 i2c_writel(i2c_dev, val, I2C_FIFO_CONTROL);
370
371 if (tegra_i2c_flush_fifos(i2c_dev))
372 err = -ETIMEDOUT;
373
374 clk_disable(i2c_dev->clk);
Todd Poynorcb63c622011-04-25 15:32:25 -0600375
376 if (i2c_dev->irq_disabled) {
377 i2c_dev->irq_disabled = 0;
378 enable_irq(i2c_dev->irq);
379 }
380
Colin Crossdb811ca2011-02-20 17:14:21 -0800381 return err;
382}
383
384static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
385{
386 u32 status;
387 const u32 status_err = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
388 struct tegra_i2c_dev *i2c_dev = dev_id;
389
390 status = i2c_readl(i2c_dev, I2C_INT_STATUS);
391
392 if (status == 0) {
Todd Poynorcb63c622011-04-25 15:32:25 -0600393 dev_warn(i2c_dev->dev, "irq status 0 %08x %08x %08x\n",
394 i2c_readl(i2c_dev, I2C_PACKET_TRANSFER_STATUS),
395 i2c_readl(i2c_dev, I2C_STATUS),
396 i2c_readl(i2c_dev, I2C_CNFG));
397 i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT;
398
399 if (!i2c_dev->irq_disabled) {
400 disable_irq_nosync(i2c_dev->irq);
401 i2c_dev->irq_disabled = 1;
402 }
403
404 complete(&i2c_dev->msg_complete);
405 goto err;
Colin Crossdb811ca2011-02-20 17:14:21 -0800406 }
407
408 if (unlikely(status & status_err)) {
409 if (status & I2C_INT_NO_ACK)
410 i2c_dev->msg_err |= I2C_ERR_NO_ACK;
411 if (status & I2C_INT_ARBITRATION_LOST)
412 i2c_dev->msg_err |= I2C_ERR_ARBITRATION_LOST;
413 complete(&i2c_dev->msg_complete);
414 goto err;
415 }
416
417 if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) {
418 if (i2c_dev->msg_buf_remaining)
419 tegra_i2c_empty_rx_fifo(i2c_dev);
420 else
421 BUG();
422 }
423
424 if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
425 if (i2c_dev->msg_buf_remaining)
426 tegra_i2c_fill_tx_fifo(i2c_dev);
427 else
428 tegra_i2c_mask_irq(i2c_dev, I2C_INT_TX_FIFO_DATA_REQ);
429 }
430
Doug Anderson96219c32011-08-30 11:46:10 -0600431 if (status & I2C_INT_PACKET_XFER_COMPLETE) {
432 BUG_ON(i2c_dev->msg_buf_remaining);
Colin Crossdb811ca2011-02-20 17:14:21 -0800433 complete(&i2c_dev->msg_complete);
Doug Anderson96219c32011-08-30 11:46:10 -0600434 }
Colin Crossdb811ca2011-02-20 17:14:21 -0800435
436 i2c_writel(i2c_dev, status, I2C_INT_STATUS);
437 if (i2c_dev->is_dvc)
438 dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
439 return IRQ_HANDLED;
440err:
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300441 /* An error occurred, mask all interrupts */
Colin Crossdb811ca2011-02-20 17:14:21 -0800442 tegra_i2c_mask_irq(i2c_dev, I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST |
443 I2C_INT_PACKET_XFER_COMPLETE | I2C_INT_TX_FIFO_DATA_REQ |
444 I2C_INT_RX_FIFO_DATA_REQ);
445 i2c_writel(i2c_dev, status, I2C_INT_STATUS);
Todd Poynorcb63c622011-04-25 15:32:25 -0600446 if (i2c_dev->is_dvc)
447 dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
Colin Crossdb811ca2011-02-20 17:14:21 -0800448 return IRQ_HANDLED;
449}
450
451static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
452 struct i2c_msg *msg, int stop)
453{
454 u32 packet_header;
455 u32 int_mask;
456 int ret;
457
458 tegra_i2c_flush_fifos(i2c_dev);
459 i2c_writel(i2c_dev, 0xFF, I2C_INT_STATUS);
460
461 if (msg->len == 0)
462 return -EINVAL;
463
464 i2c_dev->msg_buf = msg->buf;
465 i2c_dev->msg_buf_remaining = msg->len;
466 i2c_dev->msg_err = I2C_ERR_NONE;
467 i2c_dev->msg_read = (msg->flags & I2C_M_RD);
468 INIT_COMPLETION(i2c_dev->msg_complete);
469
470 packet_header = (0 << PACKET_HEADER0_HEADER_SIZE_SHIFT) |
471 PACKET_HEADER0_PROTOCOL_I2C |
472 (i2c_dev->cont_id << PACKET_HEADER0_CONT_ID_SHIFT) |
473 (1 << PACKET_HEADER0_PACKET_ID_SHIFT);
474 i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
475
476 packet_header = msg->len - 1;
477 i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
478
479 packet_header = msg->addr << I2C_HEADER_SLAVE_ADDR_SHIFT;
480 packet_header |= I2C_HEADER_IE_ENABLE;
Erik Gilling2078cf32011-04-25 15:32:26 -0600481 if (!stop)
482 packet_header |= I2C_HEADER_REPEAT_START;
Colin Crossdb811ca2011-02-20 17:14:21 -0800483 if (msg->flags & I2C_M_TEN)
484 packet_header |= I2C_HEADER_10BIT_ADDR;
485 if (msg->flags & I2C_M_IGNORE_NAK)
486 packet_header |= I2C_HEADER_CONT_ON_NAK;
Colin Crossdb811ca2011-02-20 17:14:21 -0800487 if (msg->flags & I2C_M_RD)
488 packet_header |= I2C_HEADER_READ;
489 i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
490
491 if (!(msg->flags & I2C_M_RD))
492 tegra_i2c_fill_tx_fifo(i2c_dev);
493
494 int_mask = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
495 if (msg->flags & I2C_M_RD)
496 int_mask |= I2C_INT_RX_FIFO_DATA_REQ;
497 else if (i2c_dev->msg_buf_remaining)
498 int_mask |= I2C_INT_TX_FIFO_DATA_REQ;
499 tegra_i2c_unmask_irq(i2c_dev, int_mask);
500 dev_dbg(i2c_dev->dev, "unmasked irq: %02x\n",
501 i2c_readl(i2c_dev, I2C_INT_MASK));
502
503 ret = wait_for_completion_timeout(&i2c_dev->msg_complete, TEGRA_I2C_TIMEOUT);
504 tegra_i2c_mask_irq(i2c_dev, int_mask);
505
506 if (WARN_ON(ret == 0)) {
507 dev_err(i2c_dev->dev, "i2c transfer timed out\n");
508
509 tegra_i2c_init(i2c_dev);
510 return -ETIMEDOUT;
511 }
512
513 dev_dbg(i2c_dev->dev, "transfer complete: %d %d %d\n",
514 ret, completion_done(&i2c_dev->msg_complete), i2c_dev->msg_err);
515
516 if (likely(i2c_dev->msg_err == I2C_ERR_NONE))
517 return 0;
518
519 tegra_i2c_init(i2c_dev);
520 if (i2c_dev->msg_err == I2C_ERR_NO_ACK) {
521 if (msg->flags & I2C_M_IGNORE_NAK)
522 return 0;
523 return -EREMOTEIO;
524 }
525
526 return -EIO;
527}
528
529static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
530 int num)
531{
532 struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
533 int i;
534 int ret = 0;
535
536 if (i2c_dev->is_suspended)
537 return -EBUSY;
538
539 clk_enable(i2c_dev->clk);
540 for (i = 0; i < num; i++) {
541 int stop = (i == (num - 1)) ? 1 : 0;
542 ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], stop);
543 if (ret)
544 break;
545 }
546 clk_disable(i2c_dev->clk);
547 return ret ?: i;
548}
549
550static u32 tegra_i2c_func(struct i2c_adapter *adap)
551{
Mike Rapoport048e29c2011-08-30 11:46:09 -0600552 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
Colin Crossdb811ca2011-02-20 17:14:21 -0800553}
554
555static const struct i2c_algorithm tegra_i2c_algo = {
556 .master_xfer = tegra_i2c_xfer,
557 .functionality = tegra_i2c_func,
558};
559
560static int tegra_i2c_probe(struct platform_device *pdev)
561{
562 struct tegra_i2c_dev *i2c_dev;
563 struct tegra_i2c_platform_data *pdata = pdev->dev.platform_data;
564 struct resource *res;
565 struct resource *iomem;
566 struct clk *clk;
567 struct clk *i2c_clk;
John Bonesio5c470f32011-06-22 09:16:56 -0700568 const unsigned int *prop;
Colin Crossdb811ca2011-02-20 17:14:21 -0800569 void *base;
570 int irq;
571 int ret = 0;
572
573 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
574 if (!res) {
575 dev_err(&pdev->dev, "no mem resource\n");
576 return -EINVAL;
577 }
578 iomem = request_mem_region(res->start, resource_size(res), pdev->name);
579 if (!iomem) {
580 dev_err(&pdev->dev, "I2C region already claimed\n");
581 return -EBUSY;
582 }
583
584 base = ioremap(iomem->start, resource_size(iomem));
585 if (!base) {
586 dev_err(&pdev->dev, "Cannot ioremap I2C region\n");
587 return -ENOMEM;
588 }
589
590 res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
591 if (!res) {
592 dev_err(&pdev->dev, "no irq resource\n");
593 ret = -EINVAL;
594 goto err_iounmap;
595 }
596 irq = res->start;
597
598 clk = clk_get(&pdev->dev, NULL);
599 if (IS_ERR(clk)) {
600 dev_err(&pdev->dev, "missing controller clock");
601 ret = PTR_ERR(clk);
602 goto err_release_region;
603 }
604
605 i2c_clk = clk_get(&pdev->dev, "i2c");
606 if (IS_ERR(i2c_clk)) {
607 dev_err(&pdev->dev, "missing bus clock");
608 ret = PTR_ERR(i2c_clk);
609 goto err_clk_put;
610 }
611
612 i2c_dev = kzalloc(sizeof(struct tegra_i2c_dev), GFP_KERNEL);
613 if (!i2c_dev) {
614 ret = -ENOMEM;
615 goto err_i2c_clk_put;
616 }
617
618 i2c_dev->base = base;
619 i2c_dev->clk = clk;
620 i2c_dev->i2c_clk = i2c_clk;
621 i2c_dev->iomem = iomem;
622 i2c_dev->adapter.algo = &tegra_i2c_algo;
623 i2c_dev->irq = irq;
624 i2c_dev->cont_id = pdev->id;
625 i2c_dev->dev = &pdev->dev;
John Bonesio5c470f32011-06-22 09:16:56 -0700626
627 i2c_dev->bus_clk_rate = 100000; /* default clock rate */
628 if (pdata) {
629 i2c_dev->bus_clk_rate = pdata->bus_clk_rate;
630
631 } else if (i2c_dev->dev->of_node) { /* if there is a device tree node ... */
632 prop = of_get_property(i2c_dev->dev->of_node,
633 "clock-frequency", NULL);
634 if (prop)
635 i2c_dev->bus_clk_rate = be32_to_cpup(prop);
636 }
Colin Crossdb811ca2011-02-20 17:14:21 -0800637
638 if (pdev->id == 3)
639 i2c_dev->is_dvc = 1;
640 init_completion(&i2c_dev->msg_complete);
641
642 platform_set_drvdata(pdev, i2c_dev);
643
644 ret = tegra_i2c_init(i2c_dev);
645 if (ret) {
646 dev_err(&pdev->dev, "Failed to initialize i2c controller");
647 goto err_free;
648 }
649
650 ret = request_irq(i2c_dev->irq, tegra_i2c_isr, 0, pdev->name, i2c_dev);
651 if (ret) {
652 dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq);
653 goto err_free;
654 }
655
656 clk_enable(i2c_dev->i2c_clk);
657
658 i2c_set_adapdata(&i2c_dev->adapter, i2c_dev);
659 i2c_dev->adapter.owner = THIS_MODULE;
660 i2c_dev->adapter.class = I2C_CLASS_HWMON;
661 strlcpy(i2c_dev->adapter.name, "Tegra I2C adapter",
662 sizeof(i2c_dev->adapter.name));
663 i2c_dev->adapter.algo = &tegra_i2c_algo;
664 i2c_dev->adapter.dev.parent = &pdev->dev;
665 i2c_dev->adapter.nr = pdev->id;
John Bonesio5c470f32011-06-22 09:16:56 -0700666 i2c_dev->adapter.dev.of_node = pdev->dev.of_node;
Colin Crossdb811ca2011-02-20 17:14:21 -0800667
668 ret = i2c_add_numbered_adapter(&i2c_dev->adapter);
669 if (ret) {
670 dev_err(&pdev->dev, "Failed to add I2C adapter\n");
671 goto err_free_irq;
672 }
673
John Bonesio5c470f32011-06-22 09:16:56 -0700674 of_i2c_register_devices(&i2c_dev->adapter);
675
Colin Crossdb811ca2011-02-20 17:14:21 -0800676 return 0;
677err_free_irq:
678 free_irq(i2c_dev->irq, i2c_dev);
679err_free:
680 kfree(i2c_dev);
681err_i2c_clk_put:
682 clk_put(i2c_clk);
683err_clk_put:
684 clk_put(clk);
685err_release_region:
686 release_mem_region(iomem->start, resource_size(iomem));
687err_iounmap:
688 iounmap(base);
689 return ret;
690}
691
692static int tegra_i2c_remove(struct platform_device *pdev)
693{
694 struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
695 i2c_del_adapter(&i2c_dev->adapter);
696 free_irq(i2c_dev->irq, i2c_dev);
697 clk_put(i2c_dev->i2c_clk);
698 clk_put(i2c_dev->clk);
699 release_mem_region(i2c_dev->iomem->start,
700 resource_size(i2c_dev->iomem));
701 iounmap(i2c_dev->base);
702 kfree(i2c_dev);
703 return 0;
704}
705
706#ifdef CONFIG_PM
707static int tegra_i2c_suspend(struct platform_device *pdev, pm_message_t state)
708{
709 struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
710
711 i2c_lock_adapter(&i2c_dev->adapter);
712 i2c_dev->is_suspended = true;
713 i2c_unlock_adapter(&i2c_dev->adapter);
714
715 return 0;
716}
717
718static int tegra_i2c_resume(struct platform_device *pdev)
719{
720 struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
721 int ret;
722
723 i2c_lock_adapter(&i2c_dev->adapter);
724
725 ret = tegra_i2c_init(i2c_dev);
726
727 if (ret) {
728 i2c_unlock_adapter(&i2c_dev->adapter);
729 return ret;
730 }
731
732 i2c_dev->is_suspended = false;
733
734 i2c_unlock_adapter(&i2c_dev->adapter);
735
736 return 0;
737}
738#endif
739
John Bonesio406bd182011-08-30 11:46:08 -0600740#if defined(CONFIG_OF)
741/* Match table for of_platform binding */
742static const struct of_device_id tegra_i2c_of_match[] __devinitconst = {
743 { .compatible = "nvidia,tegra20-i2c", },
744 {},
745};
746MODULE_DEVICE_TABLE(of, tegra_i2c_of_match);
747#else
748#define tegra_i2c_of_match NULL
749#endif
750
Colin Crossdb811ca2011-02-20 17:14:21 -0800751static struct platform_driver tegra_i2c_driver = {
752 .probe = tegra_i2c_probe,
753 .remove = tegra_i2c_remove,
754#ifdef CONFIG_PM
755 .suspend = tegra_i2c_suspend,
756 .resume = tegra_i2c_resume,
757#endif
758 .driver = {
759 .name = "tegra-i2c",
760 .owner = THIS_MODULE,
John Bonesio406bd182011-08-30 11:46:08 -0600761 .of_match_table = tegra_i2c_of_match,
Colin Crossdb811ca2011-02-20 17:14:21 -0800762 },
763};
764
765static int __init tegra_i2c_init_driver(void)
766{
767 return platform_driver_register(&tegra_i2c_driver);
768}
769
770static void __exit tegra_i2c_exit_driver(void)
771{
772 platform_driver_unregister(&tegra_i2c_driver);
773}
774
775subsys_initcall(tegra_i2c_init_driver);
776module_exit(tegra_i2c_exit_driver);
777
778MODULE_DESCRIPTION("nVidia Tegra2 I2C Bus Controller driver");
779MODULE_AUTHOR("Colin Cross");
780MODULE_LICENSE("GPL v2");