2 * Copyright (C) 2002 Motorola GSG-China
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version 2
7 * of the License, or (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
15 * Darius Augulis, Teltonika Inc.
18 * Implementation of I2C Adapter/Algorithm Driver
19 * for I2C Bus integrated in Freescale i.MX/MXC processors
21 * Derived from Motorola GSG China I2C example driver
23 * Copyright (C) 2005 Torsten Koschorrek <koschorrek at synertronixx.de
24 * Copyright (C) 2005 Matthias Blaschke <blaschke at synertronixx.de
25 * Copyright (C) 2007 RightHand Technologies, Inc.
26 * Copyright (C) 2008 Darius Augulis <darius.augulis at teltonika.lt>
28 * Copyright 2013 Freescale Semiconductor, Inc.
32 #include <linux/clk.h>
33 #include <linux/completion.h>
34 #include <linux/delay.h>
35 #include <linux/dma-mapping.h>
36 #include <linux/dmaengine.h>
37 #include <linux/dmapool.h>
38 #include <linux/err.h>
39 #include <linux/errno.h>
40 #include <linux/i2c.h>
41 #include <linux/init.h>
42 #include <linux/interrupt.h>
44 #include <linux/kernel.h>
45 #include <linux/module.h>
47 #include <linux/of_device.h>
48 #include <linux/of_dma.h>
49 #include <linux/of_gpio.h>
50 #include <linux/pinctrl/consumer.h>
51 #include <linux/platform_data/i2c-imx.h>
52 #include <linux/platform_device.h>
53 #include <linux/pm_runtime.h>
54 #include <linux/sched.h>
55 #include <linux/slab.h>
57 /* This will be the driver name the kernel reports */
58 #define DRIVER_NAME "imx-i2c"
61 #define IMX_I2C_BIT_RATE 100000 /* 100kHz */
64 * Enable DMA if transfer byte size is bigger than this threshold.
65 * As the hardware request, it must bigger than 4 bytes.\
66 * I have set '16' here, maybe it's not the best but I think it's
69 #define DMA_THRESHOLD 16
70 #define DMA_TIMEOUT 1000
73 * the I2C register offset is different between SoCs,
74 * to provid support for all these chips, split the
75 * register offset into a fixed base address and a
76 * variable shift value, then the full register offset
77 * will be calculated by
78 * reg_off = ( reg_base_addr << reg_shift)
80 #define IMX_I2C_IADR 0x00 /* i2c slave address */
81 #define IMX_I2C_IFDR 0x01 /* i2c frequency divider */
82 #define IMX_I2C_I2CR 0x02 /* i2c control */
83 #define IMX_I2C_I2SR 0x03 /* i2c status */
84 #define IMX_I2C_I2DR 0x04 /* i2c transfer data */
86 #define IMX_I2C_REGSHIFT 2
87 #define VF610_I2C_REGSHIFT 0
89 /* Bits of IMX I2C registers */
90 #define I2SR_RXAK 0x01
95 #define I2SR_IAAS 0x40
97 #define I2CR_DMAEN 0x02
98 #define I2CR_RSTA 0x04
99 #define I2CR_TXAK 0x08
100 #define I2CR_MTX 0x10
101 #define I2CR_MSTA 0x20
102 #define I2CR_IIEN 0x40
103 #define I2CR_IEN 0x80
105 /* register bits different operating codes definition:
106 * 1) I2SR: Interrupt flags clear operation differ between SoCs:
107 * - write zero to clear(w0c) INT flag on i.MX,
108 * - but write one to clear(w1c) INT flag on Vybrid.
109 * 2) I2CR: I2C module enable operation also differ between SoCs:
110 * - set I2CR_IEN bit enable the module on i.MX,
111 * - but clear I2CR_IEN bit enable the module on Vybrid.
113 #define I2SR_CLR_OPCODE_W0C 0x0
114 #define I2SR_CLR_OPCODE_W1C (I2SR_IAL | I2SR_IIF)
115 #define I2CR_IEN_OPCODE_0 0x0
116 #define I2CR_IEN_OPCODE_1 I2CR_IEN
118 #define I2C_PM_TIMEOUT 10 /* ms */
121 * sorted list of clock divider, register value pairs
122 * taken from table 26-5, p.26-9, Freescale i.MX
123 * Integrated Portable System Processor Reference Manual
124 * Document Number: MC9328MXLRM, Rev. 5.1, 06/2007
126 * Duplicated divider values removed from list
128 struct imx_i2c_clk_pair {
133 static struct imx_i2c_clk_pair imx_i2c_clk_div[] = {
134 { 22, 0x20 }, { 24, 0x21 }, { 26, 0x22 }, { 28, 0x23 },
135 { 30, 0x00 }, { 32, 0x24 }, { 36, 0x25 }, { 40, 0x26 },
136 { 42, 0x03 }, { 44, 0x27 }, { 48, 0x28 }, { 52, 0x05 },
137 { 56, 0x29 }, { 60, 0x06 }, { 64, 0x2A }, { 72, 0x2B },
138 { 80, 0x2C }, { 88, 0x09 }, { 96, 0x2D }, { 104, 0x0A },
139 { 112, 0x2E }, { 128, 0x2F }, { 144, 0x0C }, { 160, 0x30 },
140 { 192, 0x31 }, { 224, 0x32 }, { 240, 0x0F }, { 256, 0x33 },
141 { 288, 0x10 }, { 320, 0x34 }, { 384, 0x35 }, { 448, 0x36 },
142 { 480, 0x13 }, { 512, 0x37 }, { 576, 0x14 }, { 640, 0x38 },
143 { 768, 0x39 }, { 896, 0x3A }, { 960, 0x17 }, { 1024, 0x3B },
144 { 1152, 0x18 }, { 1280, 0x3C }, { 1536, 0x3D }, { 1792, 0x3E },
145 { 1920, 0x1B }, { 2048, 0x3F }, { 2304, 0x1C }, { 2560, 0x1D },
146 { 3072, 0x1E }, { 3840, 0x1F }
149 /* Vybrid VF610 clock divider, register value pairs */
150 static struct imx_i2c_clk_pair vf610_i2c_clk_div[] = {
151 { 20, 0x00 }, { 22, 0x01 }, { 24, 0x02 }, { 26, 0x03 },
152 { 28, 0x04 }, { 30, 0x05 }, { 32, 0x09 }, { 34, 0x06 },
153 { 36, 0x0A }, { 40, 0x07 }, { 44, 0x0C }, { 48, 0x0D },
154 { 52, 0x43 }, { 56, 0x0E }, { 60, 0x45 }, { 64, 0x12 },
155 { 68, 0x0F }, { 72, 0x13 }, { 80, 0x14 }, { 88, 0x15 },
156 { 96, 0x19 }, { 104, 0x16 }, { 112, 0x1A }, { 128, 0x17 },
157 { 136, 0x4F }, { 144, 0x1C }, { 160, 0x1D }, { 176, 0x55 },
158 { 192, 0x1E }, { 208, 0x56 }, { 224, 0x22 }, { 228, 0x24 },
159 { 240, 0x1F }, { 256, 0x23 }, { 288, 0x5C }, { 320, 0x25 },
160 { 384, 0x26 }, { 448, 0x2A }, { 480, 0x27 }, { 512, 0x2B },
161 { 576, 0x2C }, { 640, 0x2D }, { 768, 0x31 }, { 896, 0x32 },
162 { 960, 0x2F }, { 1024, 0x33 }, { 1152, 0x34 }, { 1280, 0x35 },
163 { 1536, 0x36 }, { 1792, 0x3A }, { 1920, 0x37 }, { 2048, 0x3B },
164 { 2304, 0x3C }, { 2560, 0x3D }, { 3072, 0x3E }, { 3584, 0x7A },
165 { 3840, 0x3F }, { 4096, 0x7B }, { 5120, 0x7D }, { 6144, 0x7E },
174 struct imx_i2c_hwdata {
175 enum imx_i2c_type devtype;
177 struct imx_i2c_clk_pair *clk_div;
179 unsigned i2sr_clr_opcode;
180 unsigned i2cr_ien_opcode;
184 struct dma_chan *chan_tx;
185 struct dma_chan *chan_rx;
186 struct dma_chan *chan_using;
187 struct completion cmd_complete;
189 unsigned int dma_len;
190 enum dma_transfer_direction dma_transfer_dir;
191 enum dma_data_direction dma_data_dir;
194 struct imx_i2c_struct {
195 struct i2c_adapter adapter;
198 wait_queue_head_t queue;
200 unsigned int disable_delay;
202 unsigned int ifdr; /* IMX_I2C_IFDR */
203 unsigned int cur_clk;
204 unsigned int bitrate;
205 const struct imx_i2c_hwdata *hwdata;
206 struct i2c_bus_recovery_info rinfo;
208 struct pinctrl *pinctrl;
209 struct pinctrl_state *pinctrl_pins_default;
210 struct pinctrl_state *pinctrl_pins_gpio;
212 struct imx_i2c_dma *dma;
215 static const struct imx_i2c_hwdata imx1_i2c_hwdata = {
217 .regshift = IMX_I2C_REGSHIFT,
218 .clk_div = imx_i2c_clk_div,
219 .ndivs = ARRAY_SIZE(imx_i2c_clk_div),
220 .i2sr_clr_opcode = I2SR_CLR_OPCODE_W0C,
221 .i2cr_ien_opcode = I2CR_IEN_OPCODE_1,
225 static const struct imx_i2c_hwdata imx21_i2c_hwdata = {
226 .devtype = IMX21_I2C,
227 .regshift = IMX_I2C_REGSHIFT,
228 .clk_div = imx_i2c_clk_div,
229 .ndivs = ARRAY_SIZE(imx_i2c_clk_div),
230 .i2sr_clr_opcode = I2SR_CLR_OPCODE_W0C,
231 .i2cr_ien_opcode = I2CR_IEN_OPCODE_1,
235 static struct imx_i2c_hwdata vf610_i2c_hwdata = {
236 .devtype = VF610_I2C,
237 .regshift = VF610_I2C_REGSHIFT,
238 .clk_div = vf610_i2c_clk_div,
239 .ndivs = ARRAY_SIZE(vf610_i2c_clk_div),
240 .i2sr_clr_opcode = I2SR_CLR_OPCODE_W1C,
241 .i2cr_ien_opcode = I2CR_IEN_OPCODE_0,
245 static const struct platform_device_id imx_i2c_devtype[] = {
248 .driver_data = (kernel_ulong_t)&imx1_i2c_hwdata,
251 .driver_data = (kernel_ulong_t)&imx21_i2c_hwdata,
256 MODULE_DEVICE_TABLE(platform, imx_i2c_devtype);
258 static const struct of_device_id i2c_imx_dt_ids[] = {
259 { .compatible = "fsl,imx1-i2c", .data = &imx1_i2c_hwdata, },
260 { .compatible = "fsl,imx21-i2c", .data = &imx21_i2c_hwdata, },
261 { .compatible = "fsl,vf610-i2c", .data = &vf610_i2c_hwdata, },
264 MODULE_DEVICE_TABLE(of, i2c_imx_dt_ids);
266 static inline int is_imx1_i2c(struct imx_i2c_struct *i2c_imx)
268 return i2c_imx->hwdata->devtype == IMX1_I2C;
271 static inline void imx_i2c_write_reg(unsigned int val,
272 struct imx_i2c_struct *i2c_imx, unsigned int reg)
274 writeb(val, i2c_imx->base + (reg << i2c_imx->hwdata->regshift));
277 static inline unsigned char imx_i2c_read_reg(struct imx_i2c_struct *i2c_imx,
280 return readb(i2c_imx->base + (reg << i2c_imx->hwdata->regshift));
283 /* Functions for DMA support */
284 static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
287 struct imx_i2c_dma *dma;
288 struct dma_slave_config dma_sconfig;
289 struct device *dev = &i2c_imx->adapter.dev;
292 dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
296 dma->chan_tx = dma_request_slave_channel(dev, "tx");
298 dev_dbg(dev, "can't request DMA tx channel\n");
302 dma_sconfig.dst_addr = phy_addr +
303 (IMX_I2C_I2DR << i2c_imx->hwdata->regshift);
304 dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
305 dma_sconfig.dst_maxburst = 1;
306 dma_sconfig.direction = DMA_MEM_TO_DEV;
307 ret = dmaengine_slave_config(dma->chan_tx, &dma_sconfig);
309 dev_dbg(dev, "can't configure tx channel\n");
313 dma->chan_rx = dma_request_slave_channel(dev, "rx");
315 dev_dbg(dev, "can't request DMA rx channel\n");
319 dma_sconfig.src_addr = phy_addr +
320 (IMX_I2C_I2DR << i2c_imx->hwdata->regshift);
321 dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
322 dma_sconfig.src_maxburst = 1;
323 dma_sconfig.direction = DMA_DEV_TO_MEM;
324 ret = dmaengine_slave_config(dma->chan_rx, &dma_sconfig);
326 dev_dbg(dev, "can't configure rx channel\n");
331 init_completion(&dma->cmd_complete);
332 dev_info(dev, "using %s (tx) and %s (rx) for DMA transfers\n",
333 dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx));
338 dma_release_channel(dma->chan_rx);
340 dma_release_channel(dma->chan_tx);
342 devm_kfree(dev, dma);
343 dev_info(dev, "can't use DMA, using PIO instead.\n");
346 static void i2c_imx_dma_callback(void *arg)
348 struct imx_i2c_struct *i2c_imx = (struct imx_i2c_struct *)arg;
349 struct imx_i2c_dma *dma = i2c_imx->dma;
351 dma_unmap_single(dma->chan_using->device->dev, dma->dma_buf,
352 dma->dma_len, dma->dma_data_dir);
353 complete(&dma->cmd_complete);
356 static int i2c_imx_dma_xfer(struct imx_i2c_struct *i2c_imx,
357 struct i2c_msg *msgs)
359 struct imx_i2c_dma *dma = i2c_imx->dma;
360 struct dma_async_tx_descriptor *txdesc;
361 struct device *dev = &i2c_imx->adapter.dev;
362 struct device *chan_dev = dma->chan_using->device->dev;
364 dma->dma_buf = dma_map_single(chan_dev, msgs->buf,
365 dma->dma_len, dma->dma_data_dir);
366 if (dma_mapping_error(chan_dev, dma->dma_buf)) {
367 dev_err(dev, "DMA mapping failed\n");
371 txdesc = dmaengine_prep_slave_single(dma->chan_using, dma->dma_buf,
372 dma->dma_len, dma->dma_transfer_dir,
373 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
375 dev_err(dev, "Not able to get desc for DMA xfer\n");
379 txdesc->callback = i2c_imx_dma_callback;
380 txdesc->callback_param = i2c_imx;
381 if (dma_submit_error(dmaengine_submit(txdesc))) {
382 dev_err(dev, "DMA submit failed\n");
386 dma_async_issue_pending(dma->chan_using);
390 dmaengine_terminate_all(dma->chan_using);
392 dma_unmap_single(chan_dev, dma->dma_buf,
393 dma->dma_len, dma->dma_data_dir);
398 static void i2c_imx_dma_free(struct imx_i2c_struct *i2c_imx)
400 struct imx_i2c_dma *dma = i2c_imx->dma;
405 dma_release_channel(dma->chan_tx);
408 dma_release_channel(dma->chan_rx);
411 dma->chan_using = NULL;
414 static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
416 unsigned long orig_jiffies = jiffies;
419 dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
422 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
424 /* check for arbitration lost */
425 if (temp & I2SR_IAL) {
427 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
431 if (for_busy && (temp & I2SR_IBB))
433 if (!for_busy && !(temp & I2SR_IBB))
435 if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
436 dev_dbg(&i2c_imx->adapter.dev,
437 "<%s> I2C bus is busy\n", __func__);
446 static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
448 wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10);
450 if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
451 dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
454 dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
459 static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
461 if (imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR) & I2SR_RXAK) {
462 dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
463 return -ENXIO; /* No ACK */
466 dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__);
470 static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx)
472 struct imx_i2c_clk_pair *i2c_clk_div = i2c_imx->hwdata->clk_div;
473 unsigned int i2c_clk_rate;
477 /* Divider value calculation */
478 i2c_clk_rate = clk_get_rate(i2c_imx->clk);
479 if (i2c_imx->cur_clk == i2c_clk_rate)
482 i2c_imx->cur_clk = i2c_clk_rate;
484 div = (i2c_clk_rate + i2c_imx->bitrate - 1) / i2c_imx->bitrate;
485 if (div < i2c_clk_div[0].div)
487 else if (div > i2c_clk_div[i2c_imx->hwdata->ndivs - 1].div)
488 i = i2c_imx->hwdata->ndivs - 1;
490 for (i = 0; i2c_clk_div[i].div < div; i++)
493 /* Store divider value */
494 i2c_imx->ifdr = i2c_clk_div[i].val;
497 * There dummy delay is calculated.
498 * It should be about one I2C clock period long.
499 * This delay is used in I2C bus disable function
500 * to fix chip hardware bug.
502 i2c_imx->disable_delay = (500000U * i2c_clk_div[i].div
503 + (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
505 #ifdef CONFIG_I2C_DEBUG_BUS
506 dev_dbg(&i2c_imx->adapter.dev, "I2C_CLK=%d, REQ DIV=%d\n",
508 dev_dbg(&i2c_imx->adapter.dev, "IFDR[IC]=0x%x, REAL DIV=%d\n",
509 i2c_clk_div[i].val, i2c_clk_div[i].div);
513 static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
515 unsigned int temp = 0;
518 dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
520 i2c_imx_set_clk(i2c_imx);
522 imx_i2c_write_reg(i2c_imx->ifdr, i2c_imx, IMX_I2C_IFDR);
523 /* Enable I2C controller */
524 imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, IMX_I2C_I2SR);
525 imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode, i2c_imx, IMX_I2C_I2CR);
527 /* Wait controller to be stable */
530 /* Start I2C transaction */
531 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
533 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
534 result = i2c_imx_bus_busy(i2c_imx, 1);
537 i2c_imx->stopped = 0;
539 temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
541 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
545 static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
547 unsigned int temp = 0;
549 if (!i2c_imx->stopped) {
550 /* Stop I2C transaction */
551 dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
552 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
553 temp &= ~(I2CR_MSTA | I2CR_MTX);
556 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
558 if (is_imx1_i2c(i2c_imx)) {
560 * This delay caused by an i.MXL hardware bug.
561 * If no (or too short) delay, no "STOP" bit will be generated.
563 udelay(i2c_imx->disable_delay);
566 if (!i2c_imx->stopped) {
567 i2c_imx_bus_busy(i2c_imx, 0);
568 i2c_imx->stopped = 1;
571 /* Disable I2C controller */
572 temp = i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN,
573 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
576 static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
578 struct imx_i2c_struct *i2c_imx = dev_id;
581 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
582 if (temp & I2SR_IIF) {
583 /* save status register */
584 i2c_imx->i2csr = temp;
586 temp |= (i2c_imx->hwdata->i2sr_clr_opcode & I2SR_IIF);
587 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
588 wake_up(&i2c_imx->queue);
595 static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx,
596 struct i2c_msg *msgs)
599 unsigned long time_left;
600 unsigned int temp = 0;
601 unsigned long orig_jiffies = jiffies;
602 struct imx_i2c_dma *dma = i2c_imx->dma;
603 struct device *dev = &i2c_imx->adapter.dev;
605 dma->chan_using = dma->chan_tx;
606 dma->dma_transfer_dir = DMA_MEM_TO_DEV;
607 dma->dma_data_dir = DMA_TO_DEVICE;
608 dma->dma_len = msgs->len - 1;
609 result = i2c_imx_dma_xfer(i2c_imx, msgs);
613 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
615 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
618 * Write slave address.
619 * The first byte must be transmitted by the CPU.
621 imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
622 reinit_completion(&i2c_imx->dma->cmd_complete);
623 time_left = wait_for_completion_timeout(
624 &i2c_imx->dma->cmd_complete,
625 msecs_to_jiffies(DMA_TIMEOUT));
626 if (time_left == 0) {
627 dmaengine_terminate_all(dma->chan_using);
631 /* Waiting for transfer complete. */
633 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
636 if (time_after(jiffies, orig_jiffies +
637 msecs_to_jiffies(DMA_TIMEOUT))) {
638 dev_dbg(dev, "<%s> Timeout\n", __func__);
644 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
646 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
648 /* The last data byte must be transferred by the CPU. */
649 imx_i2c_write_reg(msgs->buf[msgs->len-1],
650 i2c_imx, IMX_I2C_I2DR);
651 result = i2c_imx_trx_complete(i2c_imx);
655 return i2c_imx_acked(i2c_imx);
658 static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx,
659 struct i2c_msg *msgs, bool is_lastmsg)
662 unsigned long time_left;
664 unsigned long orig_jiffies = jiffies;
665 struct imx_i2c_dma *dma = i2c_imx->dma;
666 struct device *dev = &i2c_imx->adapter.dev;
668 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
670 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
672 dma->chan_using = dma->chan_rx;
673 dma->dma_transfer_dir = DMA_DEV_TO_MEM;
674 dma->dma_data_dir = DMA_FROM_DEVICE;
675 /* The last two data bytes must be transferred by the CPU. */
676 dma->dma_len = msgs->len - 2;
677 result = i2c_imx_dma_xfer(i2c_imx, msgs);
681 reinit_completion(&i2c_imx->dma->cmd_complete);
682 time_left = wait_for_completion_timeout(
683 &i2c_imx->dma->cmd_complete,
684 msecs_to_jiffies(DMA_TIMEOUT));
685 if (time_left == 0) {
686 dmaengine_terminate_all(dma->chan_using);
690 /* waiting for transfer complete. */
692 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
695 if (time_after(jiffies, orig_jiffies +
696 msecs_to_jiffies(DMA_TIMEOUT))) {
697 dev_dbg(dev, "<%s> Timeout\n", __func__);
703 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
705 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
707 /* read n-1 byte data */
708 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
710 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
712 msgs->buf[msgs->len-2] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
713 /* read n byte data */
714 result = i2c_imx_trx_complete(i2c_imx);
720 * It must generate STOP before read I2DR to prevent
721 * controller from generating another clock cycle
723 dev_dbg(dev, "<%s> clear MSTA\n", __func__);
724 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
725 temp &= ~(I2CR_MSTA | I2CR_MTX);
726 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
727 i2c_imx_bus_busy(i2c_imx, 0);
728 i2c_imx->stopped = 1;
731 * For i2c master receiver repeat restart operation like:
732 * read -> repeat MSTA -> read/write
733 * The controller must set MTX before read the last byte in
734 * the first read operation, otherwise the first read cost
735 * one extra clock cycle.
737 temp = readb(i2c_imx->base + IMX_I2C_I2CR);
739 writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
741 msgs->buf[msgs->len-1] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
746 static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
750 dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
751 __func__, msgs->addr << 1);
753 /* write slave address */
754 imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
755 result = i2c_imx_trx_complete(i2c_imx);
758 result = i2c_imx_acked(i2c_imx);
761 dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
764 for (i = 0; i < msgs->len; i++) {
765 dev_dbg(&i2c_imx->adapter.dev,
766 "<%s> write byte: B%d=0x%X\n",
767 __func__, i, msgs->buf[i]);
768 imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
769 result = i2c_imx_trx_complete(i2c_imx);
772 result = i2c_imx_acked(i2c_imx);
779 static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bool is_lastmsg)
783 int block_data = msgs->flags & I2C_M_RECV_LEN;
785 dev_dbg(&i2c_imx->adapter.dev,
786 "<%s> write slave address: addr=0x%x\n",
787 __func__, (msgs->addr << 1) | 0x01);
789 /* write slave address */
790 imx_i2c_write_reg((msgs->addr << 1) | 0x01, i2c_imx, IMX_I2C_I2DR);
791 result = i2c_imx_trx_complete(i2c_imx);
794 result = i2c_imx_acked(i2c_imx);
798 dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__);
800 /* setup bus to read data */
801 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
805 * Reset the I2CR_TXAK flag initially for SMBus block read since the
808 if ((msgs->len - 1) || block_data)
810 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
811 imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); /* dummy read */
813 dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
815 if (i2c_imx->dma && msgs->len >= DMA_THRESHOLD && !block_data)
816 return i2c_imx_dma_read(i2c_imx, msgs, is_lastmsg);
819 for (i = 0; i < msgs->len; i++) {
822 result = i2c_imx_trx_complete(i2c_imx);
826 * First byte is the length of remaining packet
827 * in the SMBus block data read. Add it to
830 if ((!i) && block_data) {
831 len = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
832 if ((len == 0) || (len > I2C_SMBUS_BLOCK_MAX))
834 dev_dbg(&i2c_imx->adapter.dev,
835 "<%s> read length: 0x%X\n",
839 if (i == (msgs->len - 1)) {
842 * It must generate STOP before read I2DR to prevent
843 * controller from generating another clock cycle
845 dev_dbg(&i2c_imx->adapter.dev,
846 "<%s> clear MSTA\n", __func__);
847 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
848 temp &= ~(I2CR_MSTA | I2CR_MTX);
849 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
850 i2c_imx_bus_busy(i2c_imx, 0);
851 i2c_imx->stopped = 1;
854 * For i2c master receiver repeat restart operation like:
855 * read -> repeat MSTA -> read/write
856 * The controller must set MTX before read the last byte in
857 * the first read operation, otherwise the first read cost
858 * one extra clock cycle.
860 temp = readb(i2c_imx->base + IMX_I2C_I2CR);
862 writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
864 } else if (i == (msgs->len - 2)) {
865 dev_dbg(&i2c_imx->adapter.dev,
866 "<%s> set TXAK\n", __func__);
867 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
869 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
871 if ((!i) && block_data)
874 msgs->buf[i] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
875 dev_dbg(&i2c_imx->adapter.dev,
876 "<%s> read byte: B%d=0x%X\n",
877 __func__, i, msgs->buf[i]);
882 static int i2c_imx_xfer(struct i2c_adapter *adapter,
883 struct i2c_msg *msgs, int num)
885 unsigned int i, temp;
887 bool is_lastmsg = false;
888 struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
890 dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
892 result = pm_runtime_get_sync(i2c_imx->adapter.dev.parent);
896 /* Start I2C transfer */
897 result = i2c_imx_start(i2c_imx);
899 if (i2c_imx->adapter.bus_recovery_info) {
900 i2c_recover_bus(&i2c_imx->adapter);
901 result = i2c_imx_start(i2c_imx);
908 /* read/write data */
909 for (i = 0; i < num; i++) {
914 dev_dbg(&i2c_imx->adapter.dev,
915 "<%s> repeated start\n", __func__);
916 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
918 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
919 result = i2c_imx_bus_busy(i2c_imx, 1);
923 dev_dbg(&i2c_imx->adapter.dev,
924 "<%s> transfer message: %d\n", __func__, i);
925 /* write/read data */
926 #ifdef CONFIG_I2C_DEBUG_BUS
927 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
928 dev_dbg(&i2c_imx->adapter.dev,
929 "<%s> CONTROL: IEN=%d, IIEN=%d, MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n",
931 (temp & I2CR_IEN ? 1 : 0), (temp & I2CR_IIEN ? 1 : 0),
932 (temp & I2CR_MSTA ? 1 : 0), (temp & I2CR_MTX ? 1 : 0),
933 (temp & I2CR_TXAK ? 1 : 0), (temp & I2CR_RSTA ? 1 : 0));
934 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
935 dev_dbg(&i2c_imx->adapter.dev,
936 "<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n",
938 (temp & I2SR_ICF ? 1 : 0), (temp & I2SR_IAAS ? 1 : 0),
939 (temp & I2SR_IBB ? 1 : 0), (temp & I2SR_IAL ? 1 : 0),
940 (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0),
941 (temp & I2SR_RXAK ? 1 : 0));
943 if (msgs[i].flags & I2C_M_RD)
944 result = i2c_imx_read(i2c_imx, &msgs[i], is_lastmsg);
946 if (i2c_imx->dma && msgs[i].len >= DMA_THRESHOLD)
947 result = i2c_imx_dma_write(i2c_imx, &msgs[i]);
949 result = i2c_imx_write(i2c_imx, &msgs[i]);
956 /* Stop I2C transfer */
957 i2c_imx_stop(i2c_imx);
959 pm_runtime_mark_last_busy(i2c_imx->adapter.dev.parent);
960 pm_runtime_put_autosuspend(i2c_imx->adapter.dev.parent);
963 dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
964 (result < 0) ? "error" : "success msg",
965 (result < 0) ? result : num);
966 return (result < 0) ? result : num;
969 static void i2c_imx_prepare_recovery(struct i2c_adapter *adap)
971 struct imx_i2c_struct *i2c_imx;
973 i2c_imx = container_of(adap, struct imx_i2c_struct, adapter);
975 pinctrl_select_state(i2c_imx->pinctrl, i2c_imx->pinctrl_pins_gpio);
978 static void i2c_imx_unprepare_recovery(struct i2c_adapter *adap)
980 struct imx_i2c_struct *i2c_imx;
982 i2c_imx = container_of(adap, struct imx_i2c_struct, adapter);
984 pinctrl_select_state(i2c_imx->pinctrl, i2c_imx->pinctrl_pins_default);
987 static void i2c_imx_init_recovery_info(struct imx_i2c_struct *i2c_imx,
988 struct platform_device *pdev)
990 struct i2c_bus_recovery_info *rinfo = &i2c_imx->rinfo;
992 i2c_imx->pinctrl_pins_default = pinctrl_lookup_state(i2c_imx->pinctrl,
993 PINCTRL_STATE_DEFAULT);
994 i2c_imx->pinctrl_pins_gpio = pinctrl_lookup_state(i2c_imx->pinctrl,
996 rinfo->sda_gpio = of_get_named_gpio(pdev->dev.of_node, "sda-gpios", 0);
997 rinfo->scl_gpio = of_get_named_gpio(pdev->dev.of_node, "scl-gpios", 0);
999 if (!gpio_is_valid(rinfo->sda_gpio) ||
1000 !gpio_is_valid(rinfo->scl_gpio) ||
1001 IS_ERR(i2c_imx->pinctrl_pins_default) ||
1002 IS_ERR(i2c_imx->pinctrl_pins_gpio)) {
1003 dev_dbg(&pdev->dev, "recovery information incomplete\n");
1007 dev_dbg(&pdev->dev, "using scl-gpio %d and sda-gpio %d for recovery\n",
1008 rinfo->sda_gpio, rinfo->scl_gpio);
1010 rinfo->prepare_recovery = i2c_imx_prepare_recovery;
1011 rinfo->unprepare_recovery = i2c_imx_unprepare_recovery;
1012 rinfo->recover_bus = i2c_generic_gpio_recovery;
1013 i2c_imx->adapter.bus_recovery_info = rinfo;
1016 static u32 i2c_imx_func(struct i2c_adapter *adapter)
1018 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
1019 | I2C_FUNC_SMBUS_READ_BLOCK_DATA;
1022 static struct i2c_algorithm i2c_imx_algo = {
1023 .master_xfer = i2c_imx_xfer,
1024 .functionality = i2c_imx_func,
1027 static int i2c_imx_probe(struct platform_device *pdev)
1029 const struct of_device_id *of_id = of_match_device(i2c_imx_dt_ids,
1031 struct imx_i2c_struct *i2c_imx;
1032 struct resource *res;
1033 struct imxi2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
1036 dma_addr_t phy_addr;
1038 dev_dbg(&pdev->dev, "<%s>\n", __func__);
1040 irq = platform_get_irq(pdev, 0);
1042 dev_err(&pdev->dev, "can't get irq number\n");
1046 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1047 base = devm_ioremap_resource(&pdev->dev, res);
1049 return PTR_ERR(base);
1051 phy_addr = (dma_addr_t)res->start;
1052 i2c_imx = devm_kzalloc(&pdev->dev, sizeof(*i2c_imx), GFP_KERNEL);
1057 i2c_imx->hwdata = of_id->data;
1059 i2c_imx->hwdata = (struct imx_i2c_hwdata *)
1060 platform_get_device_id(pdev)->driver_data;
1062 /* Setup i2c_imx driver structure */
1063 strlcpy(i2c_imx->adapter.name, pdev->name, sizeof(i2c_imx->adapter.name));
1064 i2c_imx->adapter.owner = THIS_MODULE;
1065 i2c_imx->adapter.algo = &i2c_imx_algo;
1066 i2c_imx->adapter.dev.parent = &pdev->dev;
1067 i2c_imx->adapter.nr = pdev->id;
1068 i2c_imx->adapter.dev.of_node = pdev->dev.of_node;
1069 i2c_imx->base = base;
1072 i2c_imx->clk = devm_clk_get(&pdev->dev, NULL);
1073 if (IS_ERR(i2c_imx->clk)) {
1074 dev_err(&pdev->dev, "can't get I2C clock\n");
1075 return PTR_ERR(i2c_imx->clk);
1078 ret = clk_prepare_enable(i2c_imx->clk);
1080 dev_err(&pdev->dev, "can't enable I2C clock, ret=%d\n", ret);
1084 i2c_imx->pinctrl = devm_pinctrl_get(&pdev->dev);
1085 if (IS_ERR(i2c_imx->pinctrl)) {
1086 ret = PTR_ERR(i2c_imx->pinctrl);
1091 ret = devm_request_irq(&pdev->dev, irq, i2c_imx_isr, 0,
1092 pdev->name, i2c_imx);
1094 dev_err(&pdev->dev, "can't claim irq %d\n", irq);
1099 init_waitqueue_head(&i2c_imx->queue);
1101 /* Set up adapter data */
1102 i2c_set_adapdata(&i2c_imx->adapter, i2c_imx);
1104 /* Set up platform driver data */
1105 platform_set_drvdata(pdev, i2c_imx);
1107 pm_runtime_set_autosuspend_delay(&pdev->dev, I2C_PM_TIMEOUT);
1108 pm_runtime_use_autosuspend(&pdev->dev);
1109 pm_runtime_set_active(&pdev->dev);
1110 pm_runtime_enable(&pdev->dev);
1112 ret = pm_runtime_get_sync(&pdev->dev);
1116 /* Set up clock divider */
1117 i2c_imx->bitrate = IMX_I2C_BIT_RATE;
1118 ret = of_property_read_u32(pdev->dev.of_node,
1119 "clock-frequency", &i2c_imx->bitrate);
1120 if (ret < 0 && pdata && pdata->bitrate)
1121 i2c_imx->bitrate = pdata->bitrate;
1123 /* Set up chip registers to defaults */
1124 imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN,
1125 i2c_imx, IMX_I2C_I2CR);
1126 imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, IMX_I2C_I2SR);
1128 i2c_imx_init_recovery_info(i2c_imx, pdev);
1130 /* Add I2C adapter */
1131 ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
1133 dev_err(&pdev->dev, "registration failed\n");
1137 pm_runtime_mark_last_busy(&pdev->dev);
1138 pm_runtime_put_autosuspend(&pdev->dev);
1140 dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", irq);
1141 dev_dbg(&i2c_imx->adapter.dev, "device resources: %pR\n", res);
1142 dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
1143 i2c_imx->adapter.name);
1144 dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
1146 /* Init DMA config if supported */
1147 i2c_imx_dma_request(i2c_imx, phy_addr);
1149 return 0; /* Return OK */
1152 pm_runtime_put_noidle(&pdev->dev);
1153 pm_runtime_disable(&pdev->dev);
1154 pm_runtime_set_suspended(&pdev->dev);
1155 pm_runtime_dont_use_autosuspend(&pdev->dev);
1158 clk_disable_unprepare(i2c_imx->clk);
1162 static int i2c_imx_remove(struct platform_device *pdev)
1164 struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
1167 ret = pm_runtime_get_sync(&pdev->dev);
1171 /* remove adapter */
1172 dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n");
1173 i2c_del_adapter(&i2c_imx->adapter);
1176 i2c_imx_dma_free(i2c_imx);
1178 /* setup chip registers to defaults */
1179 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IADR);
1180 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IFDR);
1181 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2CR);
1182 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2SR);
1184 clk_disable_unprepare(i2c_imx->clk);
1186 pm_runtime_put_noidle(&pdev->dev);
1187 pm_runtime_disable(&pdev->dev);
1193 static int i2c_imx_runtime_suspend(struct device *dev)
1195 struct imx_i2c_struct *i2c_imx = dev_get_drvdata(dev);
1197 clk_disable_unprepare(i2c_imx->clk);
1202 static int i2c_imx_runtime_resume(struct device *dev)
1204 struct imx_i2c_struct *i2c_imx = dev_get_drvdata(dev);
1207 ret = clk_prepare_enable(i2c_imx->clk);
1209 dev_err(dev, "can't enable I2C clock, ret=%d\n", ret);
1214 static const struct dev_pm_ops i2c_imx_pm_ops = {
1215 SET_RUNTIME_PM_OPS(i2c_imx_runtime_suspend,
1216 i2c_imx_runtime_resume, NULL)
1218 #define I2C_IMX_PM_OPS (&i2c_imx_pm_ops)
1220 #define I2C_IMX_PM_OPS NULL
1221 #endif /* CONFIG_PM */
1223 static struct platform_driver i2c_imx_driver = {
1224 .probe = i2c_imx_probe,
1225 .remove = i2c_imx_remove,
1227 .name = DRIVER_NAME,
1228 .pm = I2C_IMX_PM_OPS,
1229 .of_match_table = i2c_imx_dt_ids,
1231 .id_table = imx_i2c_devtype,
1234 static int __init i2c_adap_imx_init(void)
1236 return platform_driver_register(&i2c_imx_driver);
1238 subsys_initcall(i2c_adap_imx_init);
1240 static void __exit i2c_adap_imx_exit(void)
1242 platform_driver_unregister(&i2c_imx_driver);
1244 module_exit(i2c_adap_imx_exit);
1246 MODULE_LICENSE("GPL");
1247 MODULE_AUTHOR("Darius Augulis");
1248 MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus");
1249 MODULE_ALIAS("platform:" DRIVER_NAME);