1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (C) 2002 Motorola GSG-China
6 * Darius Augulis, Teltonika Inc.
9 * Implementation of I2C Adapter/Algorithm Driver
10 * for I2C Bus integrated in Freescale i.MX/MXC processors
12 * Derived from Motorola GSG China I2C example driver
14 * Copyright (C) 2005 Torsten Koschorrek <koschorrek at synertronixx.de
15 * Copyright (C) 2005 Matthias Blaschke <blaschke at synertronixx.de
16 * Copyright (C) 2007 RightHand Technologies, Inc.
17 * Copyright (C) 2008 Darius Augulis <darius.augulis at teltonika.lt>
19 * Copyright 2013 Freescale Semiconductor, Inc.
23 #include <linux/clk.h>
24 #include <linux/completion.h>
25 #include <linux/delay.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/dmaengine.h>
28 #include <linux/dmapool.h>
29 #include <linux/err.h>
30 #include <linux/errno.h>
31 #include <linux/gpio/consumer.h>
32 #include <linux/i2c.h>
33 #include <linux/init.h>
34 #include <linux/interrupt.h>
36 #include <linux/kernel.h>
37 #include <linux/module.h>
39 #include <linux/of_device.h>
40 #include <linux/of_dma.h>
41 #include <linux/pinctrl/consumer.h>
42 #include <linux/platform_data/i2c-imx.h>
43 #include <linux/platform_device.h>
44 #include <linux/pm_runtime.h>
45 #include <linux/sched.h>
46 #include <linux/slab.h>
48 /* This will be the driver name the kernel reports */
49 #define DRIVER_NAME "imx-i2c"
52 #define IMX_I2C_BIT_RATE 100000 /* 100kHz */
55 * Enable DMA if transfer byte size is bigger than this threshold.
56 * As the hardware request, it must bigger than 4 bytes.\
57 * I have set '16' here, maybe it's not the best but I think it's
60 #define DMA_THRESHOLD 16
61 #define DMA_TIMEOUT 1000
64 * the I2C register offset is different between SoCs,
65 * to provid support for all these chips, split the
66 * register offset into a fixed base address and a
67 * variable shift value, then the full register offset
68 * will be calculated by
69 * reg_off = ( reg_base_addr << reg_shift)
71 #define IMX_I2C_IADR 0x00 /* i2c slave address */
72 #define IMX_I2C_IFDR 0x01 /* i2c frequency divider */
73 #define IMX_I2C_I2CR 0x02 /* i2c control */
74 #define IMX_I2C_I2SR 0x03 /* i2c status */
75 #define IMX_I2C_I2DR 0x04 /* i2c transfer data */
77 #define IMX_I2C_REGSHIFT 2
78 #define VF610_I2C_REGSHIFT 0
80 /* Bits of IMX I2C registers */
81 #define I2SR_RXAK 0x01
86 #define I2SR_IAAS 0x40
88 #define I2CR_DMAEN 0x02
89 #define I2CR_RSTA 0x04
90 #define I2CR_TXAK 0x08
92 #define I2CR_MSTA 0x20
93 #define I2CR_IIEN 0x40
96 /* register bits different operating codes definition:
97 * 1) I2SR: Interrupt flags clear operation differ between SoCs:
98 * - write zero to clear(w0c) INT flag on i.MX,
99 * - but write one to clear(w1c) INT flag on Vybrid.
100 * 2) I2CR: I2C module enable operation also differ between SoCs:
101 * - set I2CR_IEN bit enable the module on i.MX,
102 * - but clear I2CR_IEN bit enable the module on Vybrid.
104 #define I2SR_CLR_OPCODE_W0C 0x0
105 #define I2SR_CLR_OPCODE_W1C (I2SR_IAL | I2SR_IIF)
106 #define I2CR_IEN_OPCODE_0 0x0
107 #define I2CR_IEN_OPCODE_1 I2CR_IEN
109 #define I2C_PM_TIMEOUT 10 /* ms */
112 * sorted list of clock divider, register value pairs
113 * taken from table 26-5, p.26-9, Freescale i.MX
114 * Integrated Portable System Processor Reference Manual
115 * Document Number: MC9328MXLRM, Rev. 5.1, 06/2007
117 * Duplicated divider values removed from list
119 struct imx_i2c_clk_pair {
124 static struct imx_i2c_clk_pair imx_i2c_clk_div[] = {
125 { 22, 0x20 }, { 24, 0x21 }, { 26, 0x22 }, { 28, 0x23 },
126 { 30, 0x00 }, { 32, 0x24 }, { 36, 0x25 }, { 40, 0x26 },
127 { 42, 0x03 }, { 44, 0x27 }, { 48, 0x28 }, { 52, 0x05 },
128 { 56, 0x29 }, { 60, 0x06 }, { 64, 0x2A }, { 72, 0x2B },
129 { 80, 0x2C }, { 88, 0x09 }, { 96, 0x2D }, { 104, 0x0A },
130 { 112, 0x2E }, { 128, 0x2F }, { 144, 0x0C }, { 160, 0x30 },
131 { 192, 0x31 }, { 224, 0x32 }, { 240, 0x0F }, { 256, 0x33 },
132 { 288, 0x10 }, { 320, 0x34 }, { 384, 0x35 }, { 448, 0x36 },
133 { 480, 0x13 }, { 512, 0x37 }, { 576, 0x14 }, { 640, 0x38 },
134 { 768, 0x39 }, { 896, 0x3A }, { 960, 0x17 }, { 1024, 0x3B },
135 { 1152, 0x18 }, { 1280, 0x3C }, { 1536, 0x3D }, { 1792, 0x3E },
136 { 1920, 0x1B }, { 2048, 0x3F }, { 2304, 0x1C }, { 2560, 0x1D },
137 { 3072, 0x1E }, { 3840, 0x1F }
140 /* Vybrid VF610 clock divider, register value pairs */
141 static struct imx_i2c_clk_pair vf610_i2c_clk_div[] = {
142 { 20, 0x00 }, { 22, 0x01 }, { 24, 0x02 }, { 26, 0x03 },
143 { 28, 0x04 }, { 30, 0x05 }, { 32, 0x09 }, { 34, 0x06 },
144 { 36, 0x0A }, { 40, 0x07 }, { 44, 0x0C }, { 48, 0x0D },
145 { 52, 0x43 }, { 56, 0x0E }, { 60, 0x45 }, { 64, 0x12 },
146 { 68, 0x0F }, { 72, 0x13 }, { 80, 0x14 }, { 88, 0x15 },
147 { 96, 0x19 }, { 104, 0x16 }, { 112, 0x1A }, { 128, 0x17 },
148 { 136, 0x4F }, { 144, 0x1C }, { 160, 0x1D }, { 176, 0x55 },
149 { 192, 0x1E }, { 208, 0x56 }, { 224, 0x22 }, { 228, 0x24 },
150 { 240, 0x1F }, { 256, 0x23 }, { 288, 0x5C }, { 320, 0x25 },
151 { 384, 0x26 }, { 448, 0x2A }, { 480, 0x27 }, { 512, 0x2B },
152 { 576, 0x2C }, { 640, 0x2D }, { 768, 0x31 }, { 896, 0x32 },
153 { 960, 0x2F }, { 1024, 0x33 }, { 1152, 0x34 }, { 1280, 0x35 },
154 { 1536, 0x36 }, { 1792, 0x3A }, { 1920, 0x37 }, { 2048, 0x3B },
155 { 2304, 0x3C }, { 2560, 0x3D }, { 3072, 0x3E }, { 3584, 0x7A },
156 { 3840, 0x3F }, { 4096, 0x7B }, { 5120, 0x7D }, { 6144, 0x7E },
165 struct imx_i2c_hwdata {
166 enum imx_i2c_type devtype;
168 struct imx_i2c_clk_pair *clk_div;
170 unsigned i2sr_clr_opcode;
171 unsigned i2cr_ien_opcode;
175 struct dma_chan *chan_tx;
176 struct dma_chan *chan_rx;
177 struct dma_chan *chan_using;
178 struct completion cmd_complete;
180 unsigned int dma_len;
181 enum dma_transfer_direction dma_transfer_dir;
182 enum dma_data_direction dma_data_dir;
185 struct imx_i2c_struct {
186 struct i2c_adapter adapter;
188 struct notifier_block clk_change_nb;
190 wait_queue_head_t queue;
192 unsigned int disable_delay;
194 unsigned int ifdr; /* IMX_I2C_IFDR */
195 unsigned int cur_clk;
196 unsigned int bitrate;
197 const struct imx_i2c_hwdata *hwdata;
198 struct i2c_bus_recovery_info rinfo;
200 struct pinctrl *pinctrl;
201 struct pinctrl_state *pinctrl_pins_default;
202 struct pinctrl_state *pinctrl_pins_gpio;
204 struct imx_i2c_dma *dma;
207 static const struct imx_i2c_hwdata imx1_i2c_hwdata = {
209 .regshift = IMX_I2C_REGSHIFT,
210 .clk_div = imx_i2c_clk_div,
211 .ndivs = ARRAY_SIZE(imx_i2c_clk_div),
212 .i2sr_clr_opcode = I2SR_CLR_OPCODE_W0C,
213 .i2cr_ien_opcode = I2CR_IEN_OPCODE_1,
217 static const struct imx_i2c_hwdata imx21_i2c_hwdata = {
218 .devtype = IMX21_I2C,
219 .regshift = IMX_I2C_REGSHIFT,
220 .clk_div = imx_i2c_clk_div,
221 .ndivs = ARRAY_SIZE(imx_i2c_clk_div),
222 .i2sr_clr_opcode = I2SR_CLR_OPCODE_W0C,
223 .i2cr_ien_opcode = I2CR_IEN_OPCODE_1,
227 static struct imx_i2c_hwdata vf610_i2c_hwdata = {
228 .devtype = VF610_I2C,
229 .regshift = VF610_I2C_REGSHIFT,
230 .clk_div = vf610_i2c_clk_div,
231 .ndivs = ARRAY_SIZE(vf610_i2c_clk_div),
232 .i2sr_clr_opcode = I2SR_CLR_OPCODE_W1C,
233 .i2cr_ien_opcode = I2CR_IEN_OPCODE_0,
237 static const struct platform_device_id imx_i2c_devtype[] = {
240 .driver_data = (kernel_ulong_t)&imx1_i2c_hwdata,
243 .driver_data = (kernel_ulong_t)&imx21_i2c_hwdata,
248 MODULE_DEVICE_TABLE(platform, imx_i2c_devtype);
250 static const struct of_device_id i2c_imx_dt_ids[] = {
251 { .compatible = "fsl,imx1-i2c", .data = &imx1_i2c_hwdata, },
252 { .compatible = "fsl,imx21-i2c", .data = &imx21_i2c_hwdata, },
253 { .compatible = "fsl,vf610-i2c", .data = &vf610_i2c_hwdata, },
256 MODULE_DEVICE_TABLE(of, i2c_imx_dt_ids);
258 static inline int is_imx1_i2c(struct imx_i2c_struct *i2c_imx)
260 return i2c_imx->hwdata->devtype == IMX1_I2C;
263 static inline void imx_i2c_write_reg(unsigned int val,
264 struct imx_i2c_struct *i2c_imx, unsigned int reg)
266 writeb(val, i2c_imx->base + (reg << i2c_imx->hwdata->regshift));
269 static inline unsigned char imx_i2c_read_reg(struct imx_i2c_struct *i2c_imx,
272 return readb(i2c_imx->base + (reg << i2c_imx->hwdata->regshift));
275 /* Functions for DMA support */
276 static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
279 struct imx_i2c_dma *dma;
280 struct dma_slave_config dma_sconfig;
281 struct device *dev = &i2c_imx->adapter.dev;
284 dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
288 dma->chan_tx = dma_request_slave_channel(dev, "tx");
290 dev_dbg(dev, "can't request DMA tx channel\n");
294 dma_sconfig.dst_addr = phy_addr +
295 (IMX_I2C_I2DR << i2c_imx->hwdata->regshift);
296 dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
297 dma_sconfig.dst_maxburst = 1;
298 dma_sconfig.direction = DMA_MEM_TO_DEV;
299 ret = dmaengine_slave_config(dma->chan_tx, &dma_sconfig);
301 dev_dbg(dev, "can't configure tx channel\n");
305 dma->chan_rx = dma_request_slave_channel(dev, "rx");
307 dev_dbg(dev, "can't request DMA rx channel\n");
311 dma_sconfig.src_addr = phy_addr +
312 (IMX_I2C_I2DR << i2c_imx->hwdata->regshift);
313 dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
314 dma_sconfig.src_maxburst = 1;
315 dma_sconfig.direction = DMA_DEV_TO_MEM;
316 ret = dmaengine_slave_config(dma->chan_rx, &dma_sconfig);
318 dev_dbg(dev, "can't configure rx channel\n");
323 init_completion(&dma->cmd_complete);
324 dev_info(dev, "using %s (tx) and %s (rx) for DMA transfers\n",
325 dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx));
330 dma_release_channel(dma->chan_rx);
332 dma_release_channel(dma->chan_tx);
334 devm_kfree(dev, dma);
335 dev_info(dev, "can't use DMA, using PIO instead.\n");
338 static void i2c_imx_dma_callback(void *arg)
340 struct imx_i2c_struct *i2c_imx = (struct imx_i2c_struct *)arg;
341 struct imx_i2c_dma *dma = i2c_imx->dma;
343 dma_unmap_single(dma->chan_using->device->dev, dma->dma_buf,
344 dma->dma_len, dma->dma_data_dir);
345 complete(&dma->cmd_complete);
348 static int i2c_imx_dma_xfer(struct imx_i2c_struct *i2c_imx,
349 struct i2c_msg *msgs)
351 struct imx_i2c_dma *dma = i2c_imx->dma;
352 struct dma_async_tx_descriptor *txdesc;
353 struct device *dev = &i2c_imx->adapter.dev;
354 struct device *chan_dev = dma->chan_using->device->dev;
356 dma->dma_buf = dma_map_single(chan_dev, msgs->buf,
357 dma->dma_len, dma->dma_data_dir);
358 if (dma_mapping_error(chan_dev, dma->dma_buf)) {
359 dev_err(dev, "DMA mapping failed\n");
363 txdesc = dmaengine_prep_slave_single(dma->chan_using, dma->dma_buf,
364 dma->dma_len, dma->dma_transfer_dir,
365 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
367 dev_err(dev, "Not able to get desc for DMA xfer\n");
371 txdesc->callback = i2c_imx_dma_callback;
372 txdesc->callback_param = i2c_imx;
373 if (dma_submit_error(dmaengine_submit(txdesc))) {
374 dev_err(dev, "DMA submit failed\n");
378 dma_async_issue_pending(dma->chan_using);
382 dmaengine_terminate_all(dma->chan_using);
384 dma_unmap_single(chan_dev, dma->dma_buf,
385 dma->dma_len, dma->dma_data_dir);
390 static void i2c_imx_dma_free(struct imx_i2c_struct *i2c_imx)
392 struct imx_i2c_dma *dma = i2c_imx->dma;
397 dma_release_channel(dma->chan_tx);
400 dma_release_channel(dma->chan_rx);
403 dma->chan_using = NULL;
406 static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
408 unsigned long orig_jiffies = jiffies;
411 dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
414 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
416 /* check for arbitration lost */
417 if (temp & I2SR_IAL) {
419 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
423 if (for_busy && (temp & I2SR_IBB))
425 if (!for_busy && !(temp & I2SR_IBB))
427 if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
428 dev_dbg(&i2c_imx->adapter.dev,
429 "<%s> I2C bus is busy\n", __func__);
438 static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
440 wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10);
442 if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
443 dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
446 dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
451 static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
453 if (imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR) & I2SR_RXAK) {
454 dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
455 return -ENXIO; /* No ACK */
458 dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__);
462 static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
463 unsigned int i2c_clk_rate)
465 struct imx_i2c_clk_pair *i2c_clk_div = i2c_imx->hwdata->clk_div;
469 /* Divider value calculation */
470 if (i2c_imx->cur_clk == i2c_clk_rate)
473 i2c_imx->cur_clk = i2c_clk_rate;
475 div = (i2c_clk_rate + i2c_imx->bitrate - 1) / i2c_imx->bitrate;
476 if (div < i2c_clk_div[0].div)
478 else if (div > i2c_clk_div[i2c_imx->hwdata->ndivs - 1].div)
479 i = i2c_imx->hwdata->ndivs - 1;
481 for (i = 0; i2c_clk_div[i].div < div; i++)
484 /* Store divider value */
485 i2c_imx->ifdr = i2c_clk_div[i].val;
488 * There dummy delay is calculated.
489 * It should be about one I2C clock period long.
490 * This delay is used in I2C bus disable function
491 * to fix chip hardware bug.
493 i2c_imx->disable_delay = (500000U * i2c_clk_div[i].div
494 + (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
496 #ifdef CONFIG_I2C_DEBUG_BUS
497 dev_dbg(&i2c_imx->adapter.dev, "I2C_CLK=%d, REQ DIV=%d\n",
499 dev_dbg(&i2c_imx->adapter.dev, "IFDR[IC]=0x%x, REAL DIV=%d\n",
500 i2c_clk_div[i].val, i2c_clk_div[i].div);
504 static int i2c_imx_clk_notifier_call(struct notifier_block *nb,
505 unsigned long action, void *data)
507 struct clk_notifier_data *ndata = data;
508 struct imx_i2c_struct *i2c_imx = container_of(&ndata->clk,
509 struct imx_i2c_struct,
512 if (action & POST_RATE_CHANGE)
513 i2c_imx_set_clk(i2c_imx, ndata->new_rate);
518 static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
520 unsigned int temp = 0;
523 dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
525 imx_i2c_write_reg(i2c_imx->ifdr, i2c_imx, IMX_I2C_IFDR);
526 /* Enable I2C controller */
527 imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, IMX_I2C_I2SR);
528 imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode, i2c_imx, IMX_I2C_I2CR);
530 /* Wait controller to be stable */
531 usleep_range(50, 150);
533 /* Start I2C transaction */
534 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
536 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
537 result = i2c_imx_bus_busy(i2c_imx, 1);
540 i2c_imx->stopped = 0;
542 temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
544 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
548 static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
550 unsigned int temp = 0;
552 if (!i2c_imx->stopped) {
553 /* Stop I2C transaction */
554 dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
555 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
556 temp &= ~(I2CR_MSTA | I2CR_MTX);
559 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
561 if (is_imx1_i2c(i2c_imx)) {
563 * This delay caused by an i.MXL hardware bug.
564 * If no (or too short) delay, no "STOP" bit will be generated.
566 udelay(i2c_imx->disable_delay);
569 if (!i2c_imx->stopped) {
570 i2c_imx_bus_busy(i2c_imx, 0);
571 i2c_imx->stopped = 1;
574 /* Disable I2C controller */
575 temp = i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN,
576 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
579 static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
581 struct imx_i2c_struct *i2c_imx = dev_id;
584 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
585 if (temp & I2SR_IIF) {
586 /* save status register */
587 i2c_imx->i2csr = temp;
589 temp |= (i2c_imx->hwdata->i2sr_clr_opcode & I2SR_IIF);
590 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
591 wake_up(&i2c_imx->queue);
598 static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx,
599 struct i2c_msg *msgs)
602 unsigned long time_left;
603 unsigned int temp = 0;
604 unsigned long orig_jiffies = jiffies;
605 struct imx_i2c_dma *dma = i2c_imx->dma;
606 struct device *dev = &i2c_imx->adapter.dev;
608 dma->chan_using = dma->chan_tx;
609 dma->dma_transfer_dir = DMA_MEM_TO_DEV;
610 dma->dma_data_dir = DMA_TO_DEVICE;
611 dma->dma_len = msgs->len - 1;
612 result = i2c_imx_dma_xfer(i2c_imx, msgs);
616 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
618 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
621 * Write slave address.
622 * The first byte must be transmitted by the CPU.
624 imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR);
625 reinit_completion(&i2c_imx->dma->cmd_complete);
626 time_left = wait_for_completion_timeout(
627 &i2c_imx->dma->cmd_complete,
628 msecs_to_jiffies(DMA_TIMEOUT));
629 if (time_left == 0) {
630 dmaengine_terminate_all(dma->chan_using);
634 /* Waiting for transfer complete. */
636 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
639 if (time_after(jiffies, orig_jiffies +
640 msecs_to_jiffies(DMA_TIMEOUT))) {
641 dev_dbg(dev, "<%s> Timeout\n", __func__);
647 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
649 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
651 /* The last data byte must be transferred by the CPU. */
652 imx_i2c_write_reg(msgs->buf[msgs->len-1],
653 i2c_imx, IMX_I2C_I2DR);
654 result = i2c_imx_trx_complete(i2c_imx);
658 return i2c_imx_acked(i2c_imx);
661 static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx,
662 struct i2c_msg *msgs, bool is_lastmsg)
665 unsigned long time_left;
667 unsigned long orig_jiffies = jiffies;
668 struct imx_i2c_dma *dma = i2c_imx->dma;
669 struct device *dev = &i2c_imx->adapter.dev;
671 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
673 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
675 dma->chan_using = dma->chan_rx;
676 dma->dma_transfer_dir = DMA_DEV_TO_MEM;
677 dma->dma_data_dir = DMA_FROM_DEVICE;
678 /* The last two data bytes must be transferred by the CPU. */
679 dma->dma_len = msgs->len - 2;
680 result = i2c_imx_dma_xfer(i2c_imx, msgs);
684 reinit_completion(&i2c_imx->dma->cmd_complete);
685 time_left = wait_for_completion_timeout(
686 &i2c_imx->dma->cmd_complete,
687 msecs_to_jiffies(DMA_TIMEOUT));
688 if (time_left == 0) {
689 dmaengine_terminate_all(dma->chan_using);
693 /* waiting for transfer complete. */
695 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
698 if (time_after(jiffies, orig_jiffies +
699 msecs_to_jiffies(DMA_TIMEOUT))) {
700 dev_dbg(dev, "<%s> Timeout\n", __func__);
706 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
708 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
710 /* read n-1 byte data */
711 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
713 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
715 msgs->buf[msgs->len-2] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
716 /* read n byte data */
717 result = i2c_imx_trx_complete(i2c_imx);
723 * It must generate STOP before read I2DR to prevent
724 * controller from generating another clock cycle
726 dev_dbg(dev, "<%s> clear MSTA\n", __func__);
727 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
728 temp &= ~(I2CR_MSTA | I2CR_MTX);
729 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
730 i2c_imx_bus_busy(i2c_imx, 0);
731 i2c_imx->stopped = 1;
734 * For i2c master receiver repeat restart operation like:
735 * read -> repeat MSTA -> read/write
736 * The controller must set MTX before read the last byte in
737 * the first read operation, otherwise the first read cost
738 * one extra clock cycle.
740 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
742 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
744 msgs->buf[msgs->len-1] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
749 static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
753 dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
754 __func__, i2c_8bit_addr_from_msg(msgs));
756 /* write slave address */
757 imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR);
758 result = i2c_imx_trx_complete(i2c_imx);
761 result = i2c_imx_acked(i2c_imx);
764 dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
767 for (i = 0; i < msgs->len; i++) {
768 dev_dbg(&i2c_imx->adapter.dev,
769 "<%s> write byte: B%d=0x%X\n",
770 __func__, i, msgs->buf[i]);
771 imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
772 result = i2c_imx_trx_complete(i2c_imx);
775 result = i2c_imx_acked(i2c_imx);
782 static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bool is_lastmsg)
786 int block_data = msgs->flags & I2C_M_RECV_LEN;
788 dev_dbg(&i2c_imx->adapter.dev,
789 "<%s> write slave address: addr=0x%x\n",
790 __func__, i2c_8bit_addr_from_msg(msgs));
792 /* write slave address */
793 imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR);
794 result = i2c_imx_trx_complete(i2c_imx);
797 result = i2c_imx_acked(i2c_imx);
801 dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__);
803 /* setup bus to read data */
804 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
808 * Reset the I2CR_TXAK flag initially for SMBus block read since the
811 if ((msgs->len - 1) || block_data)
813 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
814 imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); /* dummy read */
816 dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
818 if (i2c_imx->dma && msgs->len >= DMA_THRESHOLD && !block_data)
819 return i2c_imx_dma_read(i2c_imx, msgs, is_lastmsg);
822 for (i = 0; i < msgs->len; i++) {
825 result = i2c_imx_trx_complete(i2c_imx);
829 * First byte is the length of remaining packet
830 * in the SMBus block data read. Add it to
833 if ((!i) && block_data) {
834 len = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
835 if ((len == 0) || (len > I2C_SMBUS_BLOCK_MAX))
837 dev_dbg(&i2c_imx->adapter.dev,
838 "<%s> read length: 0x%X\n",
842 if (i == (msgs->len - 1)) {
845 * It must generate STOP before read I2DR to prevent
846 * controller from generating another clock cycle
848 dev_dbg(&i2c_imx->adapter.dev,
849 "<%s> clear MSTA\n", __func__);
850 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
851 temp &= ~(I2CR_MSTA | I2CR_MTX);
852 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
853 i2c_imx_bus_busy(i2c_imx, 0);
854 i2c_imx->stopped = 1;
857 * For i2c master receiver repeat restart operation like:
858 * read -> repeat MSTA -> read/write
859 * The controller must set MTX before read the last byte in
860 * the first read operation, otherwise the first read cost
861 * one extra clock cycle.
863 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
865 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
867 } else if (i == (msgs->len - 2)) {
868 dev_dbg(&i2c_imx->adapter.dev,
869 "<%s> set TXAK\n", __func__);
870 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
872 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
874 if ((!i) && block_data)
877 msgs->buf[i] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
878 dev_dbg(&i2c_imx->adapter.dev,
879 "<%s> read byte: B%d=0x%X\n",
880 __func__, i, msgs->buf[i]);
885 static int i2c_imx_xfer(struct i2c_adapter *adapter,
886 struct i2c_msg *msgs, int num)
888 unsigned int i, temp;
890 bool is_lastmsg = false;
891 struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
893 dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
895 result = pm_runtime_get_sync(i2c_imx->adapter.dev.parent);
899 /* Start I2C transfer */
900 result = i2c_imx_start(i2c_imx);
902 if (i2c_imx->adapter.bus_recovery_info) {
903 i2c_recover_bus(&i2c_imx->adapter);
904 result = i2c_imx_start(i2c_imx);
911 /* read/write data */
912 for (i = 0; i < num; i++) {
917 dev_dbg(&i2c_imx->adapter.dev,
918 "<%s> repeated start\n", __func__);
919 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
921 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
922 result = i2c_imx_bus_busy(i2c_imx, 1);
926 dev_dbg(&i2c_imx->adapter.dev,
927 "<%s> transfer message: %d\n", __func__, i);
928 /* write/read data */
929 #ifdef CONFIG_I2C_DEBUG_BUS
930 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
931 dev_dbg(&i2c_imx->adapter.dev,
932 "<%s> CONTROL: IEN=%d, IIEN=%d, MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n",
934 (temp & I2CR_IEN ? 1 : 0), (temp & I2CR_IIEN ? 1 : 0),
935 (temp & I2CR_MSTA ? 1 : 0), (temp & I2CR_MTX ? 1 : 0),
936 (temp & I2CR_TXAK ? 1 : 0), (temp & I2CR_RSTA ? 1 : 0));
937 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
938 dev_dbg(&i2c_imx->adapter.dev,
939 "<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n",
941 (temp & I2SR_ICF ? 1 : 0), (temp & I2SR_IAAS ? 1 : 0),
942 (temp & I2SR_IBB ? 1 : 0), (temp & I2SR_IAL ? 1 : 0),
943 (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0),
944 (temp & I2SR_RXAK ? 1 : 0));
946 if (msgs[i].flags & I2C_M_RD)
947 result = i2c_imx_read(i2c_imx, &msgs[i], is_lastmsg);
949 if (i2c_imx->dma && msgs[i].len >= DMA_THRESHOLD)
950 result = i2c_imx_dma_write(i2c_imx, &msgs[i]);
952 result = i2c_imx_write(i2c_imx, &msgs[i]);
959 /* Stop I2C transfer */
960 i2c_imx_stop(i2c_imx);
962 pm_runtime_mark_last_busy(i2c_imx->adapter.dev.parent);
963 pm_runtime_put_autosuspend(i2c_imx->adapter.dev.parent);
966 dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
967 (result < 0) ? "error" : "success msg",
968 (result < 0) ? result : num);
969 return (result < 0) ? result : num;
972 static void i2c_imx_prepare_recovery(struct i2c_adapter *adap)
974 struct imx_i2c_struct *i2c_imx;
976 i2c_imx = container_of(adap, struct imx_i2c_struct, adapter);
978 pinctrl_select_state(i2c_imx->pinctrl, i2c_imx->pinctrl_pins_gpio);
981 static void i2c_imx_unprepare_recovery(struct i2c_adapter *adap)
983 struct imx_i2c_struct *i2c_imx;
985 i2c_imx = container_of(adap, struct imx_i2c_struct, adapter);
987 pinctrl_select_state(i2c_imx->pinctrl, i2c_imx->pinctrl_pins_default);
991 * We switch SCL and SDA to their GPIO function and do some bitbanging
992 * for bus recovery. These alternative pinmux settings can be
993 * described in the device tree by a separate pinctrl state "gpio". If
994 * this is missing this is not a big problem, the only implication is
995 * that we can't do bus recovery.
997 static int i2c_imx_init_recovery_info(struct imx_i2c_struct *i2c_imx,
998 struct platform_device *pdev)
1000 struct i2c_bus_recovery_info *rinfo = &i2c_imx->rinfo;
1002 i2c_imx->pinctrl = devm_pinctrl_get(&pdev->dev);
1003 if (!i2c_imx->pinctrl || IS_ERR(i2c_imx->pinctrl)) {
1004 dev_info(&pdev->dev, "can't get pinctrl, bus recovery not supported\n");
1005 return PTR_ERR(i2c_imx->pinctrl);
1008 i2c_imx->pinctrl_pins_default = pinctrl_lookup_state(i2c_imx->pinctrl,
1009 PINCTRL_STATE_DEFAULT);
1010 i2c_imx->pinctrl_pins_gpio = pinctrl_lookup_state(i2c_imx->pinctrl,
1012 rinfo->sda_gpiod = devm_gpiod_get(&pdev->dev, "sda", GPIOD_IN);
1013 rinfo->scl_gpiod = devm_gpiod_get(&pdev->dev, "scl", GPIOD_OUT_HIGH);
1015 if (PTR_ERR(rinfo->sda_gpiod) == -EPROBE_DEFER ||
1016 PTR_ERR(rinfo->scl_gpiod) == -EPROBE_DEFER) {
1017 return -EPROBE_DEFER;
1018 } else if (IS_ERR(rinfo->sda_gpiod) ||
1019 IS_ERR(rinfo->scl_gpiod) ||
1020 IS_ERR(i2c_imx->pinctrl_pins_default) ||
1021 IS_ERR(i2c_imx->pinctrl_pins_gpio)) {
1022 dev_dbg(&pdev->dev, "recovery information incomplete\n");
1026 dev_dbg(&pdev->dev, "using scl%s for recovery\n",
1027 rinfo->sda_gpiod ? ",sda" : "");
1029 rinfo->prepare_recovery = i2c_imx_prepare_recovery;
1030 rinfo->unprepare_recovery = i2c_imx_unprepare_recovery;
1031 rinfo->recover_bus = i2c_generic_scl_recovery;
1032 i2c_imx->adapter.bus_recovery_info = rinfo;
1037 static u32 i2c_imx_func(struct i2c_adapter *adapter)
1039 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
1040 | I2C_FUNC_SMBUS_READ_BLOCK_DATA;
1043 static const struct i2c_algorithm i2c_imx_algo = {
1044 .master_xfer = i2c_imx_xfer,
1045 .functionality = i2c_imx_func,
1048 static int i2c_imx_probe(struct platform_device *pdev)
1050 const struct of_device_id *of_id = of_match_device(i2c_imx_dt_ids,
1052 struct imx_i2c_struct *i2c_imx;
1053 struct resource *res;
1054 struct imxi2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
1057 dma_addr_t phy_addr;
1059 dev_dbg(&pdev->dev, "<%s>\n", __func__);
1061 irq = platform_get_irq(pdev, 0);
1063 dev_err(&pdev->dev, "can't get irq number\n");
1067 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1068 base = devm_ioremap_resource(&pdev->dev, res);
1070 return PTR_ERR(base);
1072 phy_addr = (dma_addr_t)res->start;
1073 i2c_imx = devm_kzalloc(&pdev->dev, sizeof(*i2c_imx), GFP_KERNEL);
1078 i2c_imx->hwdata = of_id->data;
1080 i2c_imx->hwdata = (struct imx_i2c_hwdata *)
1081 platform_get_device_id(pdev)->driver_data;
1083 /* Setup i2c_imx driver structure */
1084 strlcpy(i2c_imx->adapter.name, pdev->name, sizeof(i2c_imx->adapter.name));
1085 i2c_imx->adapter.owner = THIS_MODULE;
1086 i2c_imx->adapter.algo = &i2c_imx_algo;
1087 i2c_imx->adapter.dev.parent = &pdev->dev;
1088 i2c_imx->adapter.nr = pdev->id;
1089 i2c_imx->adapter.dev.of_node = pdev->dev.of_node;
1090 i2c_imx->base = base;
1093 i2c_imx->clk = devm_clk_get(&pdev->dev, NULL);
1094 if (IS_ERR(i2c_imx->clk)) {
1095 dev_err(&pdev->dev, "can't get I2C clock\n");
1096 return PTR_ERR(i2c_imx->clk);
1099 ret = clk_prepare_enable(i2c_imx->clk);
1101 dev_err(&pdev->dev, "can't enable I2C clock, ret=%d\n", ret);
1106 ret = devm_request_irq(&pdev->dev, irq, i2c_imx_isr, IRQF_SHARED,
1107 pdev->name, i2c_imx);
1109 dev_err(&pdev->dev, "can't claim irq %d\n", irq);
1114 init_waitqueue_head(&i2c_imx->queue);
1116 /* Set up adapter data */
1117 i2c_set_adapdata(&i2c_imx->adapter, i2c_imx);
1119 /* Set up platform driver data */
1120 platform_set_drvdata(pdev, i2c_imx);
1122 pm_runtime_set_autosuspend_delay(&pdev->dev, I2C_PM_TIMEOUT);
1123 pm_runtime_use_autosuspend(&pdev->dev);
1124 pm_runtime_set_active(&pdev->dev);
1125 pm_runtime_enable(&pdev->dev);
1127 ret = pm_runtime_get_sync(&pdev->dev);
1131 /* Set up clock divider */
1132 i2c_imx->bitrate = IMX_I2C_BIT_RATE;
1133 ret = of_property_read_u32(pdev->dev.of_node,
1134 "clock-frequency", &i2c_imx->bitrate);
1135 if (ret < 0 && pdata && pdata->bitrate)
1136 i2c_imx->bitrate = pdata->bitrate;
1137 i2c_imx->clk_change_nb.notifier_call = i2c_imx_clk_notifier_call;
1138 clk_notifier_register(i2c_imx->clk, &i2c_imx->clk_change_nb);
1139 i2c_imx_set_clk(i2c_imx, clk_get_rate(i2c_imx->clk));
1141 /* Set up chip registers to defaults */
1142 imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN,
1143 i2c_imx, IMX_I2C_I2CR);
1144 imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, IMX_I2C_I2SR);
1146 /* Init optional bus recovery function */
1147 ret = i2c_imx_init_recovery_info(i2c_imx, pdev);
1148 /* Give it another chance if pinctrl used is not ready yet */
1149 if (ret == -EPROBE_DEFER)
1150 goto clk_notifier_unregister;
1152 /* Add I2C adapter */
1153 ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
1155 goto clk_notifier_unregister;
1157 pm_runtime_mark_last_busy(&pdev->dev);
1158 pm_runtime_put_autosuspend(&pdev->dev);
1160 dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", irq);
1161 dev_dbg(&i2c_imx->adapter.dev, "device resources: %pR\n", res);
1162 dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
1163 i2c_imx->adapter.name);
1164 dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
1166 /* Init DMA config if supported */
1167 i2c_imx_dma_request(i2c_imx, phy_addr);
1169 return 0; /* Return OK */
1171 clk_notifier_unregister:
1172 clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb);
1174 pm_runtime_put_noidle(&pdev->dev);
1175 pm_runtime_disable(&pdev->dev);
1176 pm_runtime_set_suspended(&pdev->dev);
1177 pm_runtime_dont_use_autosuspend(&pdev->dev);
1180 clk_disable_unprepare(i2c_imx->clk);
1184 static int i2c_imx_remove(struct platform_device *pdev)
1186 struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
1189 ret = pm_runtime_get_sync(&pdev->dev);
1193 /* remove adapter */
1194 dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n");
1195 i2c_del_adapter(&i2c_imx->adapter);
1198 i2c_imx_dma_free(i2c_imx);
1200 /* setup chip registers to defaults */
1201 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IADR);
1202 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IFDR);
1203 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2CR);
1204 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2SR);
1206 clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb);
1207 clk_disable_unprepare(i2c_imx->clk);
1209 pm_runtime_put_noidle(&pdev->dev);
1210 pm_runtime_disable(&pdev->dev);
1216 static int i2c_imx_runtime_suspend(struct device *dev)
1218 struct imx_i2c_struct *i2c_imx = dev_get_drvdata(dev);
1220 clk_disable(i2c_imx->clk);
1225 static int i2c_imx_runtime_resume(struct device *dev)
1227 struct imx_i2c_struct *i2c_imx = dev_get_drvdata(dev);
1230 ret = clk_enable(i2c_imx->clk);
1232 dev_err(dev, "can't enable I2C clock, ret=%d\n", ret);
1237 static const struct dev_pm_ops i2c_imx_pm_ops = {
1238 SET_RUNTIME_PM_OPS(i2c_imx_runtime_suspend,
1239 i2c_imx_runtime_resume, NULL)
1241 #define I2C_IMX_PM_OPS (&i2c_imx_pm_ops)
1243 #define I2C_IMX_PM_OPS NULL
1244 #endif /* CONFIG_PM */
1246 static struct platform_driver i2c_imx_driver = {
1247 .probe = i2c_imx_probe,
1248 .remove = i2c_imx_remove,
1250 .name = DRIVER_NAME,
1251 .pm = I2C_IMX_PM_OPS,
1252 .of_match_table = i2c_imx_dt_ids,
1254 .id_table = imx_i2c_devtype,
1257 static int __init i2c_adap_imx_init(void)
1259 return platform_driver_register(&i2c_imx_driver);
1261 subsys_initcall(i2c_adap_imx_init);
1263 static void __exit i2c_adap_imx_exit(void)
1265 platform_driver_unregister(&i2c_imx_driver);
1267 module_exit(i2c_adap_imx_exit);
1269 MODULE_LICENSE("GPL");
1270 MODULE_AUTHOR("Darius Augulis");
1271 MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus");
1272 MODULE_ALIAS("platform:" DRIVER_NAME);