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authorLinus Torvalds <torvalds@linux-foundation.org>2012-11-03 18:14:54 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2012-11-03 18:14:54 -0400
commit209c510e3666333ad58d3080ff3ba573474a6b05 (patch)
tree0f06ffb6785cf902444484621558c52a50767998 /drivers
parent53f9313f5c465b128febf763b58156e0acae136b (diff)
parent91b370a0dbda5de92c2cf4c3bc0d18d6bf08f05f (diff)
Merge branch 'i2c-embedded/for-current' of git://git.pengutronix.de/git/wsa/linux
Pull i2c embedded fixes from Wolfram Sang: "Two patches are usual stuff. The bigger patch is needed to correct a wrong decision made in this merge window. We hoped to get the PIOQUEUE mode in the mxs driver working with DMA, but it turned out to be too broken (leading to data loss), so we now think it is best to remove it entirely and work only with DMA now. The patch should be in 3.7. IMO, so users never get the chance to use both modes in parallel." * 'i2c-embedded/for-current' of git://git.pengutronix.de/git/wsa/linux: i2c: tegra: set irq name as device name i2c-nomadik: Fixup clock handling i2c: mxs: remove broken PIOQUEUE support
Diffstat (limited to 'drivers')
-rw-r--r--drivers/i2c/busses/i2c-mxs.c186
-rw-r--r--drivers/i2c/busses/i2c-nomadik.c9
-rw-r--r--drivers/i2c/busses/i2c-tegra.c2
3 files changed, 22 insertions, 175 deletions
diff --git a/drivers/i2c/busses/i2c-mxs.c b/drivers/i2c/busses/i2c-mxs.c
index 1f58197062cf..286ca1917820 100644
--- a/drivers/i2c/busses/i2c-mxs.c
+++ b/drivers/i2c/busses/i2c-mxs.c
@@ -1,7 +1,7 @@
1/* 1/*
2 * Freescale MXS I2C bus driver 2 * Freescale MXS I2C bus driver
3 * 3 *
4 * Copyright (C) 2011 Wolfram Sang, Pengutronix e.K. 4 * Copyright (C) 2011-2012 Wolfram Sang, Pengutronix e.K.
5 * 5 *
6 * based on a (non-working) driver which was: 6 * based on a (non-working) driver which was:
7 * 7 *
@@ -35,10 +35,6 @@
35 35
36#define DRIVER_NAME "mxs-i2c" 36#define DRIVER_NAME "mxs-i2c"
37 37
38static bool use_pioqueue;
39module_param(use_pioqueue, bool, 0);
40MODULE_PARM_DESC(use_pioqueue, "Use PIOQUEUE mode for transfer instead of DMA");
41
42#define MXS_I2C_CTRL0 (0x00) 38#define MXS_I2C_CTRL0 (0x00)
43#define MXS_I2C_CTRL0_SET (0x04) 39#define MXS_I2C_CTRL0_SET (0x04)
44 40
@@ -75,23 +71,6 @@ MODULE_PARM_DESC(use_pioqueue, "Use PIOQUEUE mode for transfer instead of DMA");
75 MXS_I2C_CTRL1_SLAVE_STOP_IRQ | \ 71 MXS_I2C_CTRL1_SLAVE_STOP_IRQ | \
76 MXS_I2C_CTRL1_SLAVE_IRQ) 72 MXS_I2C_CTRL1_SLAVE_IRQ)
77 73
78#define MXS_I2C_QUEUECTRL (0x60)
79#define MXS_I2C_QUEUECTRL_SET (0x64)
80#define MXS_I2C_QUEUECTRL_CLR (0x68)
81
82#define MXS_I2C_QUEUECTRL_QUEUE_RUN 0x20
83#define MXS_I2C_QUEUECTRL_PIO_QUEUE_MODE 0x04
84
85#define MXS_I2C_QUEUESTAT (0x70)
86#define MXS_I2C_QUEUESTAT_RD_QUEUE_EMPTY 0x00002000
87#define MXS_I2C_QUEUESTAT_WRITE_QUEUE_CNT_MASK 0x0000001F
88
89#define MXS_I2C_QUEUECMD (0x80)
90
91#define MXS_I2C_QUEUEDATA (0x90)
92
93#define MXS_I2C_DATA (0xa0)
94
95 74
96#define MXS_CMD_I2C_SELECT (MXS_I2C_CTRL0_RETAIN_CLOCK | \ 75#define MXS_CMD_I2C_SELECT (MXS_I2C_CTRL0_RETAIN_CLOCK | \
97 MXS_I2C_CTRL0_PRE_SEND_START | \ 76 MXS_I2C_CTRL0_PRE_SEND_START | \
@@ -153,7 +132,6 @@ struct mxs_i2c_dev {
153 const struct mxs_i2c_speed_config *speed; 132 const struct mxs_i2c_speed_config *speed;
154 133
155 /* DMA support components */ 134 /* DMA support components */
156 bool dma_mode;
157 int dma_channel; 135 int dma_channel;
158 struct dma_chan *dmach; 136 struct dma_chan *dmach;
159 struct mxs_dma_data dma_data; 137 struct mxs_dma_data dma_data;
@@ -172,99 +150,6 @@ static void mxs_i2c_reset(struct mxs_i2c_dev *i2c)
172 writel(i2c->speed->timing2, i2c->regs + MXS_I2C_TIMING2); 150 writel(i2c->speed->timing2, i2c->regs + MXS_I2C_TIMING2);
173 151
174 writel(MXS_I2C_IRQ_MASK << 8, i2c->regs + MXS_I2C_CTRL1_SET); 152 writel(MXS_I2C_IRQ_MASK << 8, i2c->regs + MXS_I2C_CTRL1_SET);
175 if (i2c->dma_mode)
176 writel(MXS_I2C_QUEUECTRL_PIO_QUEUE_MODE,
177 i2c->regs + MXS_I2C_QUEUECTRL_CLR);
178 else
179 writel(MXS_I2C_QUEUECTRL_PIO_QUEUE_MODE,
180 i2c->regs + MXS_I2C_QUEUECTRL_SET);
181}
182
183static void mxs_i2c_pioq_setup_read(struct mxs_i2c_dev *i2c, u8 addr, int len,
184 int flags)
185{
186 u32 data;
187
188 writel(MXS_CMD_I2C_SELECT, i2c->regs + MXS_I2C_QUEUECMD);
189
190 data = (addr << 1) | I2C_SMBUS_READ;
191 writel(data, i2c->regs + MXS_I2C_DATA);
192
193 data = MXS_CMD_I2C_READ | MXS_I2C_CTRL0_XFER_COUNT(len) | flags;
194 writel(data, i2c->regs + MXS_I2C_QUEUECMD);
195}
196
197static void mxs_i2c_pioq_setup_write(struct mxs_i2c_dev *i2c,
198 u8 addr, u8 *buf, int len, int flags)
199{
200 u32 data;
201 int i, shifts_left;
202
203 data = MXS_CMD_I2C_WRITE | MXS_I2C_CTRL0_XFER_COUNT(len + 1) | flags;
204 writel(data, i2c->regs + MXS_I2C_QUEUECMD);
205
206 /*
207 * We have to copy the slave address (u8) and buffer (arbitrary number
208 * of u8) into the data register (u32). To achieve that, the u8 are put
209 * into the MSBs of 'data' which is then shifted for the next u8. When
210 * appropriate, 'data' is written to MXS_I2C_DATA. So, the first u32
211 * looks like this:
212 *
213 * 3 2 1 0
214 * 10987654|32109876|54321098|76543210
215 * --------+--------+--------+--------
216 * buffer+2|buffer+1|buffer+0|slave_addr
217 */
218
219 data = ((addr << 1) | I2C_SMBUS_WRITE) << 24;
220
221 for (i = 0; i < len; i++) {
222 data >>= 8;
223 data |= buf[i] << 24;
224 if ((i & 3) == 2)
225 writel(data, i2c->regs + MXS_I2C_DATA);
226 }
227
228 /* Write out the remaining bytes if any */
229 shifts_left = 24 - (i & 3) * 8;
230 if (shifts_left)
231 writel(data >> shifts_left, i2c->regs + MXS_I2C_DATA);
232}
233
234/*
235 * TODO: should be replaceable with a waitqueue and RD_QUEUE_IRQ (setting the
236 * rd_threshold to 1). Couldn't get this to work, though.
237 */
238static int mxs_i2c_wait_for_data(struct mxs_i2c_dev *i2c)
239{
240 unsigned long timeout = jiffies + msecs_to_jiffies(1000);
241
242 while (readl(i2c->regs + MXS_I2C_QUEUESTAT)
243 & MXS_I2C_QUEUESTAT_RD_QUEUE_EMPTY) {
244 if (time_after(jiffies, timeout))
245 return -ETIMEDOUT;
246 cond_resched();
247 }
248
249 return 0;
250}
251
252static int mxs_i2c_finish_read(struct mxs_i2c_dev *i2c, u8 *buf, int len)
253{
254 u32 uninitialized_var(data);
255 int i;
256
257 for (i = 0; i < len; i++) {
258 if ((i & 3) == 0) {
259 if (mxs_i2c_wait_for_data(i2c))
260 return -ETIMEDOUT;
261 data = readl(i2c->regs + MXS_I2C_QUEUEDATA);
262 }
263 buf[i] = data & 0xff;
264 data >>= 8;
265 }
266
267 return 0;
268} 153}
269 154
270static void mxs_i2c_dma_finish(struct mxs_i2c_dev *i2c) 155static void mxs_i2c_dma_finish(struct mxs_i2c_dev *i2c)
@@ -432,39 +317,17 @@ static int mxs_i2c_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg,
432 init_completion(&i2c->cmd_complete); 317 init_completion(&i2c->cmd_complete);
433 i2c->cmd_err = 0; 318 i2c->cmd_err = 0;
434 319
435 if (i2c->dma_mode) { 320 ret = mxs_i2c_dma_setup_xfer(adap, msg, flags);
436 ret = mxs_i2c_dma_setup_xfer(adap, msg, flags); 321 if (ret)
437 if (ret) 322 return ret;
438 return ret;
439 } else {
440 if (msg->flags & I2C_M_RD) {
441 mxs_i2c_pioq_setup_read(i2c, msg->addr,
442 msg->len, flags);
443 } else {
444 mxs_i2c_pioq_setup_write(i2c, msg->addr, msg->buf,
445 msg->len, flags);
446 }
447
448 writel(MXS_I2C_QUEUECTRL_QUEUE_RUN,
449 i2c->regs + MXS_I2C_QUEUECTRL_SET);
450 }
451 323
452 ret = wait_for_completion_timeout(&i2c->cmd_complete, 324 ret = wait_for_completion_timeout(&i2c->cmd_complete,
453 msecs_to_jiffies(1000)); 325 msecs_to_jiffies(1000));
454 if (ret == 0) 326 if (ret == 0)
455 goto timeout; 327 goto timeout;
456 328
457 if (!i2c->dma_mode && !i2c->cmd_err && (msg->flags & I2C_M_RD)) {
458 ret = mxs_i2c_finish_read(i2c, msg->buf, msg->len);
459 if (ret)
460 goto timeout;
461 }
462
463 if (i2c->cmd_err == -ENXIO) 329 if (i2c->cmd_err == -ENXIO)
464 mxs_i2c_reset(i2c); 330 mxs_i2c_reset(i2c);
465 else
466 writel(MXS_I2C_QUEUECTRL_QUEUE_RUN,
467 i2c->regs + MXS_I2C_QUEUECTRL_CLR);
468 331
469 dev_dbg(i2c->dev, "Done with err=%d\n", i2c->cmd_err); 332 dev_dbg(i2c->dev, "Done with err=%d\n", i2c->cmd_err);
470 333
@@ -472,8 +335,7 @@ static int mxs_i2c_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg,
472 335
473timeout: 336timeout:
474 dev_dbg(i2c->dev, "Timeout!\n"); 337 dev_dbg(i2c->dev, "Timeout!\n");
475 if (i2c->dma_mode) 338 mxs_i2c_dma_finish(i2c);
476 mxs_i2c_dma_finish(i2c);
477 mxs_i2c_reset(i2c); 339 mxs_i2c_reset(i2c);
478 return -ETIMEDOUT; 340 return -ETIMEDOUT;
479} 341}
@@ -502,7 +364,6 @@ static irqreturn_t mxs_i2c_isr(int this_irq, void *dev_id)
502{ 364{
503 struct mxs_i2c_dev *i2c = dev_id; 365 struct mxs_i2c_dev *i2c = dev_id;
504 u32 stat = readl(i2c->regs + MXS_I2C_CTRL1) & MXS_I2C_IRQ_MASK; 366 u32 stat = readl(i2c->regs + MXS_I2C_CTRL1) & MXS_I2C_IRQ_MASK;
505 bool is_last_cmd;
506 367
507 if (!stat) 368 if (!stat)
508 return IRQ_NONE; 369 return IRQ_NONE;
@@ -515,14 +376,6 @@ static irqreturn_t mxs_i2c_isr(int this_irq, void *dev_id)
515 /* MXS_I2C_CTRL1_OVERSIZE_XFER_TERM_IRQ is only for slaves */ 376 /* MXS_I2C_CTRL1_OVERSIZE_XFER_TERM_IRQ is only for slaves */
516 i2c->cmd_err = -EIO; 377 i2c->cmd_err = -EIO;
517 378
518 if (!i2c->dma_mode) {
519 is_last_cmd = (readl(i2c->regs + MXS_I2C_QUEUESTAT) &
520 MXS_I2C_QUEUESTAT_WRITE_QUEUE_CNT_MASK) == 0;
521
522 if (is_last_cmd || i2c->cmd_err)
523 complete(&i2c->cmd_complete);
524 }
525
526 writel(stat, i2c->regs + MXS_I2C_CTRL1_CLR); 379 writel(stat, i2c->regs + MXS_I2C_CTRL1_CLR);
527 380
528 return IRQ_HANDLED; 381 return IRQ_HANDLED;
@@ -556,23 +409,14 @@ static int mxs_i2c_get_ofdata(struct mxs_i2c_dev *i2c)
556 int ret; 409 int ret;
557 410
558 /* 411 /*
559 * The MXS I2C DMA mode is prefered and enabled by default.
560 * The PIO mode is still supported, but should be used only
561 * for debuging purposes etc.
562 */
563 i2c->dma_mode = !use_pioqueue;
564 if (!i2c->dma_mode)
565 dev_info(dev, "Using PIOQUEUE mode for I2C transfers!\n");
566
567 /*
568 * TODO: This is a temporary solution and should be changed 412 * TODO: This is a temporary solution and should be changed
569 * to use generic DMA binding later when the helpers get in. 413 * to use generic DMA binding later when the helpers get in.
570 */ 414 */
571 ret = of_property_read_u32(node, "fsl,i2c-dma-channel", 415 ret = of_property_read_u32(node, "fsl,i2c-dma-channel",
572 &i2c->dma_channel); 416 &i2c->dma_channel);
573 if (ret) { 417 if (ret) {
574 dev_warn(dev, "Failed to get DMA channel, using PIOQUEUE!\n"); 418 dev_err(dev, "Failed to get DMA channel!\n");
575 i2c->dma_mode = 0; 419 return -ENODEV;
576 } 420 }
577 421
578 ret = of_property_read_u32(node, "clock-frequency", &speed); 422 ret = of_property_read_u32(node, "clock-frequency", &speed);
@@ -634,15 +478,13 @@ static int __devinit mxs_i2c_probe(struct platform_device *pdev)
634 } 478 }
635 479
636 /* Setup the DMA */ 480 /* Setup the DMA */
637 if (i2c->dma_mode) { 481 dma_cap_zero(mask);
638 dma_cap_zero(mask); 482 dma_cap_set(DMA_SLAVE, mask);
639 dma_cap_set(DMA_SLAVE, mask); 483 i2c->dma_data.chan_irq = dmairq;
640 i2c->dma_data.chan_irq = dmairq; 484 i2c->dmach = dma_request_channel(mask, mxs_i2c_dma_filter, i2c);
641 i2c->dmach = dma_request_channel(mask, mxs_i2c_dma_filter, i2c); 485 if (!i2c->dmach) {
642 if (!i2c->dmach) { 486 dev_err(dev, "Failed to request dma\n");
643 dev_err(dev, "Failed to request dma\n"); 487 return -ENODEV;
644 return -ENODEV;
645 }
646 } 488 }
647 489
648 platform_set_drvdata(pdev, i2c); 490 platform_set_drvdata(pdev, i2c);
diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c
index 698d7acb0f08..02c3115a2dfa 100644
--- a/drivers/i2c/busses/i2c-nomadik.c
+++ b/drivers/i2c/busses/i2c-nomadik.c
@@ -644,7 +644,11 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap,
644 644
645 pm_runtime_get_sync(&dev->adev->dev); 645 pm_runtime_get_sync(&dev->adev->dev);
646 646
647 clk_enable(dev->clk); 647 status = clk_prepare_enable(dev->clk);
648 if (status) {
649 dev_err(&dev->adev->dev, "can't prepare_enable clock\n");
650 goto out_clk;
651 }
648 652
649 status = init_hw(dev); 653 status = init_hw(dev);
650 if (status) 654 if (status)
@@ -671,7 +675,8 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap,
671 } 675 }
672 676
673out: 677out:
674 clk_disable(dev->clk); 678 clk_disable_unprepare(dev->clk);
679out_clk:
675 pm_runtime_put_sync(&dev->adev->dev); 680 pm_runtime_put_sync(&dev->adev->dev);
676 681
677 dev->busy = false; 682 dev->busy = false;
diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index f981ac4e6783..dcea77bf6f50 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -742,7 +742,7 @@ static int __devinit tegra_i2c_probe(struct platform_device *pdev)
742 } 742 }
743 743
744 ret = devm_request_irq(&pdev->dev, i2c_dev->irq, 744 ret = devm_request_irq(&pdev->dev, i2c_dev->irq,
745 tegra_i2c_isr, 0, pdev->name, i2c_dev); 745 tegra_i2c_isr, 0, dev_name(&pdev->dev), i2c_dev);
746 if (ret) { 746 if (ret) {
747 dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq); 747 dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq);
748 return ret; 748 return ret;