1 // SPDX-License-Identifier: GPL-2.0+
3 * This is i.MX low power i2c controller driver.
5 * Copyright 2016 Freescale Semiconductor, Inc.
9 #include <linux/completion.h>
10 #include <linux/delay.h>
11 #include <linux/err.h>
12 #include <linux/errno.h>
13 #include <linux/i2c.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
20 #include <linux/of_device.h>
21 #include <linux/pinctrl/consumer.h>
22 #include <linux/platform_device.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/sched.h>
25 #include <linux/slab.h>
27 #define DRIVER_NAME "imx-lpi2c"
29 #define LPI2C_PARAM 0x04 /* i2c RX/TX FIFO size */
30 #define LPI2C_MCR 0x10 /* i2c contrl register */
31 #define LPI2C_MSR 0x14 /* i2c status register */
32 #define LPI2C_MIER 0x18 /* i2c interrupt enable */
33 #define LPI2C_MCFGR0 0x20 /* i2c master configuration */
34 #define LPI2C_MCFGR1 0x24 /* i2c master configuration */
35 #define LPI2C_MCFGR2 0x28 /* i2c master configuration */
36 #define LPI2C_MCFGR3 0x2C /* i2c master configuration */
37 #define LPI2C_MCCR0 0x48 /* i2c master clk configuration */
38 #define LPI2C_MCCR1 0x50 /* i2c master clk configuration */
39 #define LPI2C_MFCR 0x58 /* i2c master FIFO control */
40 #define LPI2C_MFSR 0x5C /* i2c master FIFO status */
41 #define LPI2C_MTDR 0x60 /* i2c master TX data register */
42 #define LPI2C_MRDR 0x70 /* i2c master RX data register */
45 #define TRAN_DATA 0X00
46 #define RECV_DATA 0X01
48 #define RECV_DISCARD 0X03
49 #define GEN_START 0X04
50 #define START_NACK 0X05
51 #define START_HIGH 0X06
52 #define START_HIGH_NACK 0X07
54 #define MCR_MEN BIT(0)
55 #define MCR_RST BIT(1)
56 #define MCR_DOZEN BIT(2)
57 #define MCR_DBGEN BIT(3)
58 #define MCR_RTF BIT(8)
59 #define MCR_RRF BIT(9)
60 #define MSR_TDF BIT(0)
61 #define MSR_RDF BIT(1)
62 #define MSR_SDF BIT(9)
63 #define MSR_NDF BIT(10)
64 #define MSR_ALF BIT(11)
65 #define MSR_MBF BIT(24)
66 #define MSR_BBF BIT(25)
67 #define MIER_TDIE BIT(0)
68 #define MIER_RDIE BIT(1)
69 #define MIER_SDIE BIT(9)
70 #define MIER_NDIE BIT(10)
71 #define MCFGR1_AUTOSTOP BIT(8)
72 #define MCFGR1_IGNACK BIT(9)
73 #define MRDR_RXEMPTY BIT(14)
75 #define I2C_CLK_RATIO 2
76 #define CHUNK_DATA 256
78 #define I2C_PM_TIMEOUT 10 /* ms */
81 STANDARD
, /* 100+Kbps */
83 FAST_PLUS
, /* 1.0+Mbps */
85 ULTRA_FAST
, /* 5.0+Mbps */
88 enum lpi2c_imx_pincfg
{
95 struct lpi2c_imx_struct
{
96 struct i2c_adapter adapter
;
101 struct completion complete
;
103 unsigned int delivered
;
104 unsigned int block_data
;
105 unsigned int bitrate
;
106 unsigned int txfifosize
;
107 unsigned int rxfifosize
;
108 enum lpi2c_imx_mode mode
;
111 static void lpi2c_imx_intctrl(struct lpi2c_imx_struct
*lpi2c_imx
,
114 writel(enable
, lpi2c_imx
->base
+ LPI2C_MIER
);
117 static int lpi2c_imx_bus_busy(struct lpi2c_imx_struct
*lpi2c_imx
)
119 unsigned long orig_jiffies
= jiffies
;
123 temp
= readl(lpi2c_imx
->base
+ LPI2C_MSR
);
125 /* check for arbitration lost, clear if set */
126 if (temp
& MSR_ALF
) {
127 writel(temp
, lpi2c_imx
->base
+ LPI2C_MSR
);
131 if (temp
& (MSR_BBF
| MSR_MBF
))
134 if (time_after(jiffies
, orig_jiffies
+ msecs_to_jiffies(500))) {
135 dev_dbg(&lpi2c_imx
->adapter
.dev
, "bus not work\n");
144 static void lpi2c_imx_set_mode(struct lpi2c_imx_struct
*lpi2c_imx
)
146 unsigned int bitrate
= lpi2c_imx
->bitrate
;
147 enum lpi2c_imx_mode mode
;
149 if (bitrate
< I2C_MAX_FAST_MODE_FREQ
)
151 else if (bitrate
< I2C_MAX_FAST_MODE_PLUS_FREQ
)
153 else if (bitrate
< I2C_MAX_HIGH_SPEED_MODE_FREQ
)
155 else if (bitrate
< I2C_MAX_ULTRA_FAST_MODE_FREQ
)
160 lpi2c_imx
->mode
= mode
;
163 static int lpi2c_imx_start(struct lpi2c_imx_struct
*lpi2c_imx
,
164 struct i2c_msg
*msgs
)
168 temp
= readl(lpi2c_imx
->base
+ LPI2C_MCR
);
169 temp
|= MCR_RRF
| MCR_RTF
;
170 writel(temp
, lpi2c_imx
->base
+ LPI2C_MCR
);
171 writel(0x7f00, lpi2c_imx
->base
+ LPI2C_MSR
);
173 temp
= i2c_8bit_addr_from_msg(msgs
) | (GEN_START
<< 8);
174 writel(temp
, lpi2c_imx
->base
+ LPI2C_MTDR
);
176 return lpi2c_imx_bus_busy(lpi2c_imx
);
179 static void lpi2c_imx_stop(struct lpi2c_imx_struct
*lpi2c_imx
)
181 unsigned long orig_jiffies
= jiffies
;
184 writel(GEN_STOP
<< 8, lpi2c_imx
->base
+ LPI2C_MTDR
);
187 temp
= readl(lpi2c_imx
->base
+ LPI2C_MSR
);
191 if (time_after(jiffies
, orig_jiffies
+ msecs_to_jiffies(500))) {
192 dev_dbg(&lpi2c_imx
->adapter
.dev
, "stop timeout\n");
200 /* CLKLO = I2C_CLK_RATIO * CLKHI, SETHOLD = CLKHI, DATAVD = CLKHI/2 */
201 static int lpi2c_imx_config(struct lpi2c_imx_struct
*lpi2c_imx
)
203 u8 prescale
, filt
, sethold
, clkhi
, clklo
, datavd
;
204 unsigned int clk_rate
, clk_cycle
;
205 enum lpi2c_imx_pincfg pincfg
;
208 lpi2c_imx_set_mode(lpi2c_imx
);
210 clk_rate
= clk_get_rate(lpi2c_imx
->clk
);
211 if (lpi2c_imx
->mode
== HS
|| lpi2c_imx
->mode
== ULTRA_FAST
)
216 for (prescale
= 0; prescale
<= 7; prescale
++) {
217 clk_cycle
= clk_rate
/ ((1 << prescale
) * lpi2c_imx
->bitrate
)
219 clkhi
= (clk_cycle
+ I2C_CLK_RATIO
) / (I2C_CLK_RATIO
+ 1);
220 clklo
= clk_cycle
- clkhi
;
228 /* set MCFGR1: PINCFG, PRESCALE, IGNACK */
229 if (lpi2c_imx
->mode
== ULTRA_FAST
)
233 temp
= prescale
| pincfg
<< 24;
235 if (lpi2c_imx
->mode
== ULTRA_FAST
)
236 temp
|= MCFGR1_IGNACK
;
238 writel(temp
, lpi2c_imx
->base
+ LPI2C_MCFGR1
);
240 /* set MCFGR2: FILTSDA, FILTSCL */
241 temp
= (filt
<< 16) | (filt
<< 24);
242 writel(temp
, lpi2c_imx
->base
+ LPI2C_MCFGR2
);
244 /* set MCCR: DATAVD, SETHOLD, CLKHI, CLKLO */
247 temp
= datavd
<< 24 | sethold
<< 16 | clkhi
<< 8 | clklo
;
249 if (lpi2c_imx
->mode
== HS
)
250 writel(temp
, lpi2c_imx
->base
+ LPI2C_MCCR1
);
252 writel(temp
, lpi2c_imx
->base
+ LPI2C_MCCR0
);
257 static int lpi2c_imx_master_enable(struct lpi2c_imx_struct
*lpi2c_imx
)
262 ret
= pm_runtime_get_sync(lpi2c_imx
->adapter
.dev
.parent
);
267 writel(temp
, lpi2c_imx
->base
+ LPI2C_MCR
);
268 writel(0, lpi2c_imx
->base
+ LPI2C_MCR
);
270 ret
= lpi2c_imx_config(lpi2c_imx
);
274 temp
= readl(lpi2c_imx
->base
+ LPI2C_MCR
);
276 writel(temp
, lpi2c_imx
->base
+ LPI2C_MCR
);
281 pm_runtime_mark_last_busy(lpi2c_imx
->adapter
.dev
.parent
);
282 pm_runtime_put_autosuspend(lpi2c_imx
->adapter
.dev
.parent
);
287 static int lpi2c_imx_master_disable(struct lpi2c_imx_struct
*lpi2c_imx
)
291 temp
= readl(lpi2c_imx
->base
+ LPI2C_MCR
);
293 writel(temp
, lpi2c_imx
->base
+ LPI2C_MCR
);
295 pm_runtime_mark_last_busy(lpi2c_imx
->adapter
.dev
.parent
);
296 pm_runtime_put_autosuspend(lpi2c_imx
->adapter
.dev
.parent
);
301 static int lpi2c_imx_msg_complete(struct lpi2c_imx_struct
*lpi2c_imx
)
303 unsigned long timeout
;
305 timeout
= wait_for_completion_timeout(&lpi2c_imx
->complete
, HZ
);
307 return timeout
? 0 : -ETIMEDOUT
;
310 static int lpi2c_imx_txfifo_empty(struct lpi2c_imx_struct
*lpi2c_imx
)
312 unsigned long orig_jiffies
= jiffies
;
316 txcnt
= readl(lpi2c_imx
->base
+ LPI2C_MFSR
) & 0xff;
318 if (readl(lpi2c_imx
->base
+ LPI2C_MSR
) & MSR_NDF
) {
319 dev_dbg(&lpi2c_imx
->adapter
.dev
, "NDF detected\n");
323 if (time_after(jiffies
, orig_jiffies
+ msecs_to_jiffies(500))) {
324 dev_dbg(&lpi2c_imx
->adapter
.dev
, "txfifo empty timeout\n");
334 static void lpi2c_imx_set_tx_watermark(struct lpi2c_imx_struct
*lpi2c_imx
)
336 writel(lpi2c_imx
->txfifosize
>> 1, lpi2c_imx
->base
+ LPI2C_MFCR
);
339 static void lpi2c_imx_set_rx_watermark(struct lpi2c_imx_struct
*lpi2c_imx
)
341 unsigned int temp
, remaining
;
343 remaining
= lpi2c_imx
->msglen
- lpi2c_imx
->delivered
;
345 if (remaining
> (lpi2c_imx
->rxfifosize
>> 1))
346 temp
= lpi2c_imx
->rxfifosize
>> 1;
350 writel(temp
<< 16, lpi2c_imx
->base
+ LPI2C_MFCR
);
353 static void lpi2c_imx_write_txfifo(struct lpi2c_imx_struct
*lpi2c_imx
)
355 unsigned int data
, txcnt
;
357 txcnt
= readl(lpi2c_imx
->base
+ LPI2C_MFSR
) & 0xff;
359 while (txcnt
< lpi2c_imx
->txfifosize
) {
360 if (lpi2c_imx
->delivered
== lpi2c_imx
->msglen
)
363 data
= lpi2c_imx
->tx_buf
[lpi2c_imx
->delivered
++];
364 writel(data
, lpi2c_imx
->base
+ LPI2C_MTDR
);
368 if (lpi2c_imx
->delivered
< lpi2c_imx
->msglen
)
369 lpi2c_imx_intctrl(lpi2c_imx
, MIER_TDIE
| MIER_NDIE
);
371 complete(&lpi2c_imx
->complete
);
374 static void lpi2c_imx_read_rxfifo(struct lpi2c_imx_struct
*lpi2c_imx
)
376 unsigned int blocklen
, remaining
;
377 unsigned int temp
, data
;
380 data
= readl(lpi2c_imx
->base
+ LPI2C_MRDR
);
381 if (data
& MRDR_RXEMPTY
)
384 lpi2c_imx
->rx_buf
[lpi2c_imx
->delivered
++] = data
& 0xff;
388 * First byte is the length of remaining packet in the SMBus block
389 * data read. Add it to msgs->len.
391 if (lpi2c_imx
->block_data
) {
392 blocklen
= lpi2c_imx
->rx_buf
[0];
393 lpi2c_imx
->msglen
+= blocklen
;
396 remaining
= lpi2c_imx
->msglen
- lpi2c_imx
->delivered
;
399 complete(&lpi2c_imx
->complete
);
403 /* not finished, still waiting for rx data */
404 lpi2c_imx_set_rx_watermark(lpi2c_imx
);
406 /* multiple receive commands */
407 if (lpi2c_imx
->block_data
) {
408 lpi2c_imx
->block_data
= 0;
410 temp
|= (RECV_DATA
<< 8);
411 writel(temp
, lpi2c_imx
->base
+ LPI2C_MTDR
);
412 } else if (!(lpi2c_imx
->delivered
& 0xff)) {
413 temp
= (remaining
> CHUNK_DATA
? CHUNK_DATA
: remaining
) - 1;
414 temp
|= (RECV_DATA
<< 8);
415 writel(temp
, lpi2c_imx
->base
+ LPI2C_MTDR
);
418 lpi2c_imx_intctrl(lpi2c_imx
, MIER_RDIE
);
421 static void lpi2c_imx_write(struct lpi2c_imx_struct
*lpi2c_imx
,
422 struct i2c_msg
*msgs
)
424 lpi2c_imx
->tx_buf
= msgs
->buf
;
425 lpi2c_imx_set_tx_watermark(lpi2c_imx
);
426 lpi2c_imx_write_txfifo(lpi2c_imx
);
429 static void lpi2c_imx_read(struct lpi2c_imx_struct
*lpi2c_imx
,
430 struct i2c_msg
*msgs
)
434 lpi2c_imx
->rx_buf
= msgs
->buf
;
435 lpi2c_imx
->block_data
= msgs
->flags
& I2C_M_RECV_LEN
;
437 lpi2c_imx_set_rx_watermark(lpi2c_imx
);
438 temp
= msgs
->len
> CHUNK_DATA
? CHUNK_DATA
- 1 : msgs
->len
- 1;
439 temp
|= (RECV_DATA
<< 8);
440 writel(temp
, lpi2c_imx
->base
+ LPI2C_MTDR
);
442 lpi2c_imx_intctrl(lpi2c_imx
, MIER_RDIE
| MIER_NDIE
);
445 static int lpi2c_imx_xfer(struct i2c_adapter
*adapter
,
446 struct i2c_msg
*msgs
, int num
)
448 struct lpi2c_imx_struct
*lpi2c_imx
= i2c_get_adapdata(adapter
);
452 result
= lpi2c_imx_master_enable(lpi2c_imx
);
456 for (i
= 0; i
< num
; i
++) {
457 result
= lpi2c_imx_start(lpi2c_imx
, &msgs
[i
]);
462 if (num
== 1 && msgs
[0].len
== 0)
465 lpi2c_imx
->delivered
= 0;
466 lpi2c_imx
->msglen
= msgs
[i
].len
;
467 init_completion(&lpi2c_imx
->complete
);
469 if (msgs
[i
].flags
& I2C_M_RD
)
470 lpi2c_imx_read(lpi2c_imx
, &msgs
[i
]);
472 lpi2c_imx_write(lpi2c_imx
, &msgs
[i
]);
474 result
= lpi2c_imx_msg_complete(lpi2c_imx
);
478 if (!(msgs
[i
].flags
& I2C_M_RD
)) {
479 result
= lpi2c_imx_txfifo_empty(lpi2c_imx
);
486 lpi2c_imx_stop(lpi2c_imx
);
488 temp
= readl(lpi2c_imx
->base
+ LPI2C_MSR
);
489 if ((temp
& MSR_NDF
) && !result
)
493 lpi2c_imx_master_disable(lpi2c_imx
);
495 dev_dbg(&lpi2c_imx
->adapter
.dev
, "<%s> exit with: %s: %d\n", __func__
,
496 (result
< 0) ? "error" : "success msg",
497 (result
< 0) ? result
: num
);
499 return (result
< 0) ? result
: num
;
502 static irqreturn_t
lpi2c_imx_isr(int irq
, void *dev_id
)
504 struct lpi2c_imx_struct
*lpi2c_imx
= dev_id
;
507 lpi2c_imx_intctrl(lpi2c_imx
, 0);
508 temp
= readl(lpi2c_imx
->base
+ LPI2C_MSR
);
511 lpi2c_imx_read_rxfifo(lpi2c_imx
);
514 lpi2c_imx_write_txfifo(lpi2c_imx
);
517 complete(&lpi2c_imx
->complete
);
522 static u32
lpi2c_imx_func(struct i2c_adapter
*adapter
)
524 return I2C_FUNC_I2C
| I2C_FUNC_SMBUS_EMUL
|
525 I2C_FUNC_SMBUS_READ_BLOCK_DATA
;
528 static const struct i2c_algorithm lpi2c_imx_algo
= {
529 .master_xfer
= lpi2c_imx_xfer
,
530 .functionality
= lpi2c_imx_func
,
533 static const struct of_device_id lpi2c_imx_of_match
[] = {
534 { .compatible
= "fsl,imx7ulp-lpi2c" },
537 MODULE_DEVICE_TABLE(of
, lpi2c_imx_of_match
);
539 static int lpi2c_imx_probe(struct platform_device
*pdev
)
541 struct lpi2c_imx_struct
*lpi2c_imx
;
545 lpi2c_imx
= devm_kzalloc(&pdev
->dev
, sizeof(*lpi2c_imx
), GFP_KERNEL
);
549 lpi2c_imx
->base
= devm_platform_ioremap_resource(pdev
, 0);
550 if (IS_ERR(lpi2c_imx
->base
))
551 return PTR_ERR(lpi2c_imx
->base
);
553 irq
= platform_get_irq(pdev
, 0);
555 dev_err(&pdev
->dev
, "can't get irq number\n");
559 lpi2c_imx
->adapter
.owner
= THIS_MODULE
;
560 lpi2c_imx
->adapter
.algo
= &lpi2c_imx_algo
;
561 lpi2c_imx
->adapter
.dev
.parent
= &pdev
->dev
;
562 lpi2c_imx
->adapter
.dev
.of_node
= pdev
->dev
.of_node
;
563 strlcpy(lpi2c_imx
->adapter
.name
, pdev
->name
,
564 sizeof(lpi2c_imx
->adapter
.name
));
566 lpi2c_imx
->clk
= devm_clk_get(&pdev
->dev
, NULL
);
567 if (IS_ERR(lpi2c_imx
->clk
)) {
568 dev_err(&pdev
->dev
, "can't get I2C peripheral clock\n");
569 return PTR_ERR(lpi2c_imx
->clk
);
572 ret
= of_property_read_u32(pdev
->dev
.of_node
,
573 "clock-frequency", &lpi2c_imx
->bitrate
);
575 lpi2c_imx
->bitrate
= I2C_MAX_STANDARD_MODE_FREQ
;
577 ret
= devm_request_irq(&pdev
->dev
, irq
, lpi2c_imx_isr
, 0,
578 pdev
->name
, lpi2c_imx
);
580 dev_err(&pdev
->dev
, "can't claim irq %d\n", irq
);
584 i2c_set_adapdata(&lpi2c_imx
->adapter
, lpi2c_imx
);
585 platform_set_drvdata(pdev
, lpi2c_imx
);
587 ret
= clk_prepare_enable(lpi2c_imx
->clk
);
589 dev_err(&pdev
->dev
, "clk enable failed %d\n", ret
);
593 pm_runtime_set_autosuspend_delay(&pdev
->dev
, I2C_PM_TIMEOUT
);
594 pm_runtime_use_autosuspend(&pdev
->dev
);
595 pm_runtime_get_noresume(&pdev
->dev
);
596 pm_runtime_set_active(&pdev
->dev
);
597 pm_runtime_enable(&pdev
->dev
);
599 temp
= readl(lpi2c_imx
->base
+ LPI2C_PARAM
);
600 lpi2c_imx
->txfifosize
= 1 << (temp
& 0x0f);
601 lpi2c_imx
->rxfifosize
= 1 << ((temp
>> 8) & 0x0f);
603 ret
= i2c_add_adapter(&lpi2c_imx
->adapter
);
607 pm_runtime_mark_last_busy(&pdev
->dev
);
608 pm_runtime_put_autosuspend(&pdev
->dev
);
610 dev_info(&lpi2c_imx
->adapter
.dev
, "LPI2C adapter registered\n");
615 pm_runtime_put(&pdev
->dev
);
616 pm_runtime_disable(&pdev
->dev
);
617 pm_runtime_dont_use_autosuspend(&pdev
->dev
);
622 static int lpi2c_imx_remove(struct platform_device
*pdev
)
624 struct lpi2c_imx_struct
*lpi2c_imx
= platform_get_drvdata(pdev
);
626 i2c_del_adapter(&lpi2c_imx
->adapter
);
628 pm_runtime_disable(&pdev
->dev
);
629 pm_runtime_dont_use_autosuspend(&pdev
->dev
);
634 static int __maybe_unused
lpi2c_runtime_suspend(struct device
*dev
)
636 struct lpi2c_imx_struct
*lpi2c_imx
= dev_get_drvdata(dev
);
638 clk_disable_unprepare(lpi2c_imx
->clk
);
639 pinctrl_pm_select_sleep_state(dev
);
644 static int __maybe_unused
lpi2c_runtime_resume(struct device
*dev
)
646 struct lpi2c_imx_struct
*lpi2c_imx
= dev_get_drvdata(dev
);
649 pinctrl_pm_select_default_state(dev
);
650 ret
= clk_prepare_enable(lpi2c_imx
->clk
);
652 dev_err(dev
, "failed to enable I2C clock, ret=%d\n", ret
);
659 static const struct dev_pm_ops lpi2c_pm_ops
= {
660 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend
,
661 pm_runtime_force_resume
)
662 SET_RUNTIME_PM_OPS(lpi2c_runtime_suspend
,
663 lpi2c_runtime_resume
, NULL
)
666 static struct platform_driver lpi2c_imx_driver
= {
667 .probe
= lpi2c_imx_probe
,
668 .remove
= lpi2c_imx_remove
,
671 .of_match_table
= lpi2c_imx_of_match
,
676 module_platform_driver(lpi2c_imx_driver
);
678 MODULE_AUTHOR("Gao Pan <pandy.gao@nxp.com>");
679 MODULE_DESCRIPTION("I2C adapter driver for LPI2C bus");
680 MODULE_LICENSE("GPL");