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 LPI2C_DEFAULT_RATE 100000
79 #define STARDARD_MAX_BITRATE 400000
80 #define FAST_MAX_BITRATE 1000000
81 #define FAST_PLUS_MAX_BITRATE 3400000
82 #define HIGHSPEED_MAX_BITRATE 5000000
84 #define I2C_PM_TIMEOUT 10 /* ms */
87 STANDARD
, /* 100+Kbps */
89 FAST_PLUS
, /* 1.0+Mbps */
91 ULTRA_FAST
, /* 5.0+Mbps */
94 enum lpi2c_imx_pincfg
{
101 struct lpi2c_imx_struct
{
102 struct i2c_adapter adapter
;
107 struct completion complete
;
109 unsigned int delivered
;
110 unsigned int block_data
;
111 unsigned int bitrate
;
112 unsigned int txfifosize
;
113 unsigned int rxfifosize
;
114 enum lpi2c_imx_mode mode
;
117 static void lpi2c_imx_intctrl(struct lpi2c_imx_struct
*lpi2c_imx
,
120 writel(enable
, lpi2c_imx
->base
+ LPI2C_MIER
);
123 static int lpi2c_imx_bus_busy(struct lpi2c_imx_struct
*lpi2c_imx
)
125 unsigned long orig_jiffies
= jiffies
;
129 temp
= readl(lpi2c_imx
->base
+ LPI2C_MSR
);
131 /* check for arbitration lost, clear if set */
132 if (temp
& MSR_ALF
) {
133 writel(temp
, lpi2c_imx
->base
+ LPI2C_MSR
);
137 if (temp
& (MSR_BBF
| MSR_MBF
))
140 if (time_after(jiffies
, orig_jiffies
+ msecs_to_jiffies(500))) {
141 dev_dbg(&lpi2c_imx
->adapter
.dev
, "bus not work\n");
150 static void lpi2c_imx_set_mode(struct lpi2c_imx_struct
*lpi2c_imx
)
152 unsigned int bitrate
= lpi2c_imx
->bitrate
;
153 enum lpi2c_imx_mode mode
;
155 if (bitrate
< STARDARD_MAX_BITRATE
)
157 else if (bitrate
< FAST_MAX_BITRATE
)
159 else if (bitrate
< FAST_PLUS_MAX_BITRATE
)
161 else if (bitrate
< HIGHSPEED_MAX_BITRATE
)
166 lpi2c_imx
->mode
= mode
;
169 static int lpi2c_imx_start(struct lpi2c_imx_struct
*lpi2c_imx
,
170 struct i2c_msg
*msgs
)
174 temp
= readl(lpi2c_imx
->base
+ LPI2C_MCR
);
175 temp
|= MCR_RRF
| MCR_RTF
;
176 writel(temp
, lpi2c_imx
->base
+ LPI2C_MCR
);
177 writel(0x7f00, lpi2c_imx
->base
+ LPI2C_MSR
);
179 temp
= i2c_8bit_addr_from_msg(msgs
) | (GEN_START
<< 8);
180 writel(temp
, lpi2c_imx
->base
+ LPI2C_MTDR
);
182 return lpi2c_imx_bus_busy(lpi2c_imx
);
185 static void lpi2c_imx_stop(struct lpi2c_imx_struct
*lpi2c_imx
)
187 unsigned long orig_jiffies
= jiffies
;
190 writel(GEN_STOP
<< 8, lpi2c_imx
->base
+ LPI2C_MTDR
);
193 temp
= readl(lpi2c_imx
->base
+ LPI2C_MSR
);
197 if (time_after(jiffies
, orig_jiffies
+ msecs_to_jiffies(500))) {
198 dev_dbg(&lpi2c_imx
->adapter
.dev
, "stop timeout\n");
206 /* CLKLO = I2C_CLK_RATIO * CLKHI, SETHOLD = CLKHI, DATAVD = CLKHI/2 */
207 static int lpi2c_imx_config(struct lpi2c_imx_struct
*lpi2c_imx
)
209 u8 prescale
, filt
, sethold
, clkhi
, clklo
, datavd
;
210 unsigned int clk_rate
, clk_cycle
;
211 enum lpi2c_imx_pincfg pincfg
;
214 lpi2c_imx_set_mode(lpi2c_imx
);
216 clk_rate
= clk_get_rate(lpi2c_imx
->clk
);
217 if (lpi2c_imx
->mode
== HS
|| lpi2c_imx
->mode
== ULTRA_FAST
)
222 for (prescale
= 0; prescale
<= 7; prescale
++) {
223 clk_cycle
= clk_rate
/ ((1 << prescale
) * lpi2c_imx
->bitrate
)
225 clkhi
= (clk_cycle
+ I2C_CLK_RATIO
) / (I2C_CLK_RATIO
+ 1);
226 clklo
= clk_cycle
- clkhi
;
234 /* set MCFGR1: PINCFG, PRESCALE, IGNACK */
235 if (lpi2c_imx
->mode
== ULTRA_FAST
)
239 temp
= prescale
| pincfg
<< 24;
241 if (lpi2c_imx
->mode
== ULTRA_FAST
)
242 temp
|= MCFGR1_IGNACK
;
244 writel(temp
, lpi2c_imx
->base
+ LPI2C_MCFGR1
);
246 /* set MCFGR2: FILTSDA, FILTSCL */
247 temp
= (filt
<< 16) | (filt
<< 24);
248 writel(temp
, lpi2c_imx
->base
+ LPI2C_MCFGR2
);
250 /* set MCCR: DATAVD, SETHOLD, CLKHI, CLKLO */
253 temp
= datavd
<< 24 | sethold
<< 16 | clkhi
<< 8 | clklo
;
255 if (lpi2c_imx
->mode
== HS
)
256 writel(temp
, lpi2c_imx
->base
+ LPI2C_MCCR1
);
258 writel(temp
, lpi2c_imx
->base
+ LPI2C_MCCR0
);
263 static int lpi2c_imx_master_enable(struct lpi2c_imx_struct
*lpi2c_imx
)
268 ret
= pm_runtime_get_sync(lpi2c_imx
->adapter
.dev
.parent
);
273 writel(temp
, lpi2c_imx
->base
+ LPI2C_MCR
);
274 writel(0, lpi2c_imx
->base
+ LPI2C_MCR
);
276 ret
= lpi2c_imx_config(lpi2c_imx
);
280 temp
= readl(lpi2c_imx
->base
+ LPI2C_MCR
);
282 writel(temp
, lpi2c_imx
->base
+ LPI2C_MCR
);
287 pm_runtime_mark_last_busy(lpi2c_imx
->adapter
.dev
.parent
);
288 pm_runtime_put_autosuspend(lpi2c_imx
->adapter
.dev
.parent
);
293 static int lpi2c_imx_master_disable(struct lpi2c_imx_struct
*lpi2c_imx
)
297 temp
= readl(lpi2c_imx
->base
+ LPI2C_MCR
);
299 writel(temp
, lpi2c_imx
->base
+ LPI2C_MCR
);
301 pm_runtime_mark_last_busy(lpi2c_imx
->adapter
.dev
.parent
);
302 pm_runtime_put_autosuspend(lpi2c_imx
->adapter
.dev
.parent
);
307 static int lpi2c_imx_msg_complete(struct lpi2c_imx_struct
*lpi2c_imx
)
309 unsigned long timeout
;
311 timeout
= wait_for_completion_timeout(&lpi2c_imx
->complete
, HZ
);
313 return timeout
? 0 : -ETIMEDOUT
;
316 static int lpi2c_imx_txfifo_empty(struct lpi2c_imx_struct
*lpi2c_imx
)
318 unsigned long orig_jiffies
= jiffies
;
322 txcnt
= readl(lpi2c_imx
->base
+ LPI2C_MFSR
) & 0xff;
324 if (readl(lpi2c_imx
->base
+ LPI2C_MSR
) & MSR_NDF
) {
325 dev_dbg(&lpi2c_imx
->adapter
.dev
, "NDF detected\n");
329 if (time_after(jiffies
, orig_jiffies
+ msecs_to_jiffies(500))) {
330 dev_dbg(&lpi2c_imx
->adapter
.dev
, "txfifo empty timeout\n");
340 static void lpi2c_imx_set_tx_watermark(struct lpi2c_imx_struct
*lpi2c_imx
)
342 writel(lpi2c_imx
->txfifosize
>> 1, lpi2c_imx
->base
+ LPI2C_MFCR
);
345 static void lpi2c_imx_set_rx_watermark(struct lpi2c_imx_struct
*lpi2c_imx
)
347 unsigned int temp
, remaining
;
349 remaining
= lpi2c_imx
->msglen
- lpi2c_imx
->delivered
;
351 if (remaining
> (lpi2c_imx
->rxfifosize
>> 1))
352 temp
= lpi2c_imx
->rxfifosize
>> 1;
356 writel(temp
<< 16, lpi2c_imx
->base
+ LPI2C_MFCR
);
359 static void lpi2c_imx_write_txfifo(struct lpi2c_imx_struct
*lpi2c_imx
)
361 unsigned int data
, txcnt
;
363 txcnt
= readl(lpi2c_imx
->base
+ LPI2C_MFSR
) & 0xff;
365 while (txcnt
< lpi2c_imx
->txfifosize
) {
366 if (lpi2c_imx
->delivered
== lpi2c_imx
->msglen
)
369 data
= lpi2c_imx
->tx_buf
[lpi2c_imx
->delivered
++];
370 writel(data
, lpi2c_imx
->base
+ LPI2C_MTDR
);
374 if (lpi2c_imx
->delivered
< lpi2c_imx
->msglen
)
375 lpi2c_imx_intctrl(lpi2c_imx
, MIER_TDIE
| MIER_NDIE
);
377 complete(&lpi2c_imx
->complete
);
380 static void lpi2c_imx_read_rxfifo(struct lpi2c_imx_struct
*lpi2c_imx
)
382 unsigned int blocklen
, remaining
;
383 unsigned int temp
, data
;
386 data
= readl(lpi2c_imx
->base
+ LPI2C_MRDR
);
387 if (data
& MRDR_RXEMPTY
)
390 lpi2c_imx
->rx_buf
[lpi2c_imx
->delivered
++] = data
& 0xff;
394 * First byte is the length of remaining packet in the SMBus block
395 * data read. Add it to msgs->len.
397 if (lpi2c_imx
->block_data
) {
398 blocklen
= lpi2c_imx
->rx_buf
[0];
399 lpi2c_imx
->msglen
+= blocklen
;
402 remaining
= lpi2c_imx
->msglen
- lpi2c_imx
->delivered
;
405 complete(&lpi2c_imx
->complete
);
409 /* not finished, still waiting for rx data */
410 lpi2c_imx_set_rx_watermark(lpi2c_imx
);
412 /* multiple receive commands */
413 if (lpi2c_imx
->block_data
) {
414 lpi2c_imx
->block_data
= 0;
416 temp
|= (RECV_DATA
<< 8);
417 writel(temp
, lpi2c_imx
->base
+ LPI2C_MTDR
);
418 } else if (!(lpi2c_imx
->delivered
& 0xff)) {
419 temp
= (remaining
> CHUNK_DATA
? CHUNK_DATA
: remaining
) - 1;
420 temp
|= (RECV_DATA
<< 8);
421 writel(temp
, lpi2c_imx
->base
+ LPI2C_MTDR
);
424 lpi2c_imx_intctrl(lpi2c_imx
, MIER_RDIE
);
427 static void lpi2c_imx_write(struct lpi2c_imx_struct
*lpi2c_imx
,
428 struct i2c_msg
*msgs
)
430 lpi2c_imx
->tx_buf
= msgs
->buf
;
431 lpi2c_imx_set_tx_watermark(lpi2c_imx
);
432 lpi2c_imx_write_txfifo(lpi2c_imx
);
435 static void lpi2c_imx_read(struct lpi2c_imx_struct
*lpi2c_imx
,
436 struct i2c_msg
*msgs
)
440 lpi2c_imx
->rx_buf
= msgs
->buf
;
441 lpi2c_imx
->block_data
= msgs
->flags
& I2C_M_RECV_LEN
;
443 lpi2c_imx_set_rx_watermark(lpi2c_imx
);
444 temp
= msgs
->len
> CHUNK_DATA
? CHUNK_DATA
- 1 : msgs
->len
- 1;
445 temp
|= (RECV_DATA
<< 8);
446 writel(temp
, lpi2c_imx
->base
+ LPI2C_MTDR
);
448 lpi2c_imx_intctrl(lpi2c_imx
, MIER_RDIE
| MIER_NDIE
);
451 static int lpi2c_imx_xfer(struct i2c_adapter
*adapter
,
452 struct i2c_msg
*msgs
, int num
)
454 struct lpi2c_imx_struct
*lpi2c_imx
= i2c_get_adapdata(adapter
);
458 result
= lpi2c_imx_master_enable(lpi2c_imx
);
462 for (i
= 0; i
< num
; i
++) {
463 result
= lpi2c_imx_start(lpi2c_imx
, &msgs
[i
]);
468 if (num
== 1 && msgs
[0].len
== 0)
471 lpi2c_imx
->delivered
= 0;
472 lpi2c_imx
->msglen
= msgs
[i
].len
;
473 init_completion(&lpi2c_imx
->complete
);
475 if (msgs
[i
].flags
& I2C_M_RD
)
476 lpi2c_imx_read(lpi2c_imx
, &msgs
[i
]);
478 lpi2c_imx_write(lpi2c_imx
, &msgs
[i
]);
480 result
= lpi2c_imx_msg_complete(lpi2c_imx
);
484 if (!(msgs
[i
].flags
& I2C_M_RD
)) {
485 result
= lpi2c_imx_txfifo_empty(lpi2c_imx
);
492 lpi2c_imx_stop(lpi2c_imx
);
494 temp
= readl(lpi2c_imx
->base
+ LPI2C_MSR
);
495 if ((temp
& MSR_NDF
) && !result
)
499 lpi2c_imx_master_disable(lpi2c_imx
);
501 dev_dbg(&lpi2c_imx
->adapter
.dev
, "<%s> exit with: %s: %d\n", __func__
,
502 (result
< 0) ? "error" : "success msg",
503 (result
< 0) ? result
: num
);
505 return (result
< 0) ? result
: num
;
508 static irqreturn_t
lpi2c_imx_isr(int irq
, void *dev_id
)
510 struct lpi2c_imx_struct
*lpi2c_imx
= dev_id
;
513 lpi2c_imx_intctrl(lpi2c_imx
, 0);
514 temp
= readl(lpi2c_imx
->base
+ LPI2C_MSR
);
517 lpi2c_imx_read_rxfifo(lpi2c_imx
);
520 lpi2c_imx_write_txfifo(lpi2c_imx
);
523 complete(&lpi2c_imx
->complete
);
528 static u32
lpi2c_imx_func(struct i2c_adapter
*adapter
)
530 return I2C_FUNC_I2C
| I2C_FUNC_SMBUS_EMUL
|
531 I2C_FUNC_SMBUS_READ_BLOCK_DATA
;
534 static const struct i2c_algorithm lpi2c_imx_algo
= {
535 .master_xfer
= lpi2c_imx_xfer
,
536 .functionality
= lpi2c_imx_func
,
539 static const struct of_device_id lpi2c_imx_of_match
[] = {
540 { .compatible
= "fsl,imx7ulp-lpi2c" },
543 MODULE_DEVICE_TABLE(of
, lpi2c_imx_of_match
);
545 static int lpi2c_imx_probe(struct platform_device
*pdev
)
547 struct lpi2c_imx_struct
*lpi2c_imx
;
548 struct resource
*res
;
552 lpi2c_imx
= devm_kzalloc(&pdev
->dev
, sizeof(*lpi2c_imx
), GFP_KERNEL
);
556 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
557 lpi2c_imx
->base
= devm_ioremap_resource(&pdev
->dev
, res
);
558 if (IS_ERR(lpi2c_imx
->base
))
559 return PTR_ERR(lpi2c_imx
->base
);
561 irq
= platform_get_irq(pdev
, 0);
563 dev_err(&pdev
->dev
, "can't get irq number\n");
567 lpi2c_imx
->adapter
.owner
= THIS_MODULE
;
568 lpi2c_imx
->adapter
.algo
= &lpi2c_imx_algo
;
569 lpi2c_imx
->adapter
.dev
.parent
= &pdev
->dev
;
570 lpi2c_imx
->adapter
.dev
.of_node
= pdev
->dev
.of_node
;
571 strlcpy(lpi2c_imx
->adapter
.name
, pdev
->name
,
572 sizeof(lpi2c_imx
->adapter
.name
));
574 lpi2c_imx
->clk
= devm_clk_get(&pdev
->dev
, NULL
);
575 if (IS_ERR(lpi2c_imx
->clk
)) {
576 dev_err(&pdev
->dev
, "can't get I2C peripheral clock\n");
577 return PTR_ERR(lpi2c_imx
->clk
);
580 ret
= of_property_read_u32(pdev
->dev
.of_node
,
581 "clock-frequency", &lpi2c_imx
->bitrate
);
583 lpi2c_imx
->bitrate
= LPI2C_DEFAULT_RATE
;
585 ret
= devm_request_irq(&pdev
->dev
, irq
, lpi2c_imx_isr
, 0,
586 pdev
->name
, lpi2c_imx
);
588 dev_err(&pdev
->dev
, "can't claim irq %d\n", irq
);
592 i2c_set_adapdata(&lpi2c_imx
->adapter
, lpi2c_imx
);
593 platform_set_drvdata(pdev
, lpi2c_imx
);
595 ret
= clk_prepare_enable(lpi2c_imx
->clk
);
597 dev_err(&pdev
->dev
, "clk enable failed %d\n", ret
);
601 pm_runtime_set_autosuspend_delay(&pdev
->dev
, I2C_PM_TIMEOUT
);
602 pm_runtime_use_autosuspend(&pdev
->dev
);
603 pm_runtime_get_noresume(&pdev
->dev
);
604 pm_runtime_set_active(&pdev
->dev
);
605 pm_runtime_enable(&pdev
->dev
);
607 temp
= readl(lpi2c_imx
->base
+ LPI2C_PARAM
);
608 lpi2c_imx
->txfifosize
= 1 << (temp
& 0x0f);
609 lpi2c_imx
->rxfifosize
= 1 << ((temp
>> 8) & 0x0f);
611 ret
= i2c_add_adapter(&lpi2c_imx
->adapter
);
615 pm_runtime_mark_last_busy(&pdev
->dev
);
616 pm_runtime_put_autosuspend(&pdev
->dev
);
618 dev_info(&lpi2c_imx
->adapter
.dev
, "LPI2C adapter registered\n");
623 pm_runtime_put(&pdev
->dev
);
624 pm_runtime_disable(&pdev
->dev
);
625 pm_runtime_dont_use_autosuspend(&pdev
->dev
);
630 static int lpi2c_imx_remove(struct platform_device
*pdev
)
632 struct lpi2c_imx_struct
*lpi2c_imx
= platform_get_drvdata(pdev
);
634 i2c_del_adapter(&lpi2c_imx
->adapter
);
636 pm_runtime_disable(&pdev
->dev
);
637 pm_runtime_dont_use_autosuspend(&pdev
->dev
);
642 #ifdef CONFIG_PM_SLEEP
643 static int lpi2c_runtime_suspend(struct device
*dev
)
645 struct lpi2c_imx_struct
*lpi2c_imx
= dev_get_drvdata(dev
);
647 clk_disable_unprepare(lpi2c_imx
->clk
);
648 pinctrl_pm_select_sleep_state(dev
);
653 static int lpi2c_runtime_resume(struct device
*dev
)
655 struct lpi2c_imx_struct
*lpi2c_imx
= dev_get_drvdata(dev
);
658 pinctrl_pm_select_default_state(dev
);
659 ret
= clk_prepare_enable(lpi2c_imx
->clk
);
661 dev_err(dev
, "failed to enable I2C clock, ret=%d\n", ret
);
668 static const struct dev_pm_ops lpi2c_pm_ops
= {
669 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend
,
670 pm_runtime_force_resume
)
671 SET_RUNTIME_PM_OPS(lpi2c_runtime_suspend
,
672 lpi2c_runtime_resume
, NULL
)
674 #define IMX_LPI2C_PM (&lpi2c_pm_ops)
676 #define IMX_LPI2C_PM NULL
679 static struct platform_driver lpi2c_imx_driver
= {
680 .probe
= lpi2c_imx_probe
,
681 .remove
= lpi2c_imx_remove
,
684 .of_match_table
= lpi2c_imx_of_match
,
689 module_platform_driver(lpi2c_imx_driver
);
691 MODULE_AUTHOR("Gao Pan <pandy.gao@nxp.com>");
692 MODULE_DESCRIPTION("I2C adapter driver for LPI2C bus");
693 MODULE_LICENSE("GPL");