2 * Freescale i.MX7D ADC driver
4 * Copyright (C) 2015 Freescale Semiconductor, Inc.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
12 #include <linux/clk.h>
13 #include <linux/completion.h>
14 #include <linux/err.h>
15 #include <linux/interrupt.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/regulator/consumer.h>
22 #include <linux/iio/iio.h>
23 #include <linux/iio/driver.h>
24 #include <linux/iio/sysfs.h>
27 #define IMX7D_REG_ADC_CH_A_CFG1 0x00
28 #define IMX7D_REG_ADC_CH_A_CFG2 0x10
29 #define IMX7D_REG_ADC_CH_B_CFG1 0x20
30 #define IMX7D_REG_ADC_CH_B_CFG2 0x30
31 #define IMX7D_REG_ADC_CH_C_CFG1 0x40
32 #define IMX7D_REG_ADC_CH_C_CFG2 0x50
33 #define IMX7D_REG_ADC_CH_D_CFG1 0x60
34 #define IMX7D_REG_ADC_CH_D_CFG2 0x70
35 #define IMX7D_REG_ADC_CH_SW_CFG 0x80
36 #define IMX7D_REG_ADC_TIMER_UNIT 0x90
37 #define IMX7D_REG_ADC_DMA_FIFO 0xa0
38 #define IMX7D_REG_ADC_FIFO_STATUS 0xb0
39 #define IMX7D_REG_ADC_INT_SIG_EN 0xc0
40 #define IMX7D_REG_ADC_INT_EN 0xd0
41 #define IMX7D_REG_ADC_INT_STATUS 0xe0
42 #define IMX7D_REG_ADC_CHA_B_CNV_RSLT 0xf0
43 #define IMX7D_REG_ADC_CHC_D_CNV_RSLT 0x100
44 #define IMX7D_REG_ADC_CH_SW_CNV_RSLT 0x110
45 #define IMX7D_REG_ADC_DMA_FIFO_DAT 0x120
46 #define IMX7D_REG_ADC_ADC_CFG 0x130
48 #define IMX7D_REG_ADC_CHANNEL_CFG2_BASE 0x10
49 #define IMX7D_EACH_CHANNEL_REG_OFFSET 0x20
51 #define IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN (0x1 << 31)
52 #define IMX7D_REG_ADC_CH_CFG1_CHANNEL_SINGLE BIT(30)
53 #define IMX7D_REG_ADC_CH_CFG1_CHANNEL_AVG_EN BIT(29)
54 #define IMX7D_REG_ADC_CH_CFG1_CHANNEL_SEL(x) ((x) << 24)
56 #define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_4 (0x0 << 12)
57 #define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_8 (0x1 << 12)
58 #define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_16 (0x2 << 12)
59 #define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_32 (0x3 << 12)
61 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_4 (0x0 << 29)
62 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_8 (0x1 << 29)
63 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_16 (0x2 << 29)
64 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_32 (0x3 << 29)
65 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_64 (0x4 << 29)
66 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_128 (0x5 << 29)
68 #define IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN BIT(31)
69 #define IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN BIT(1)
70 #define IMX7D_REG_ADC_ADC_CFG_ADC_EN BIT(0)
72 #define IMX7D_REG_ADC_INT_CHA_COV_INT_EN BIT(8)
73 #define IMX7D_REG_ADC_INT_CHB_COV_INT_EN BIT(9)
74 #define IMX7D_REG_ADC_INT_CHC_COV_INT_EN BIT(10)
75 #define IMX7D_REG_ADC_INT_CHD_COV_INT_EN BIT(11)
76 #define IMX7D_REG_ADC_INT_CHANNEL_INT_EN \
77 (IMX7D_REG_ADC_INT_CHA_COV_INT_EN | \
78 IMX7D_REG_ADC_INT_CHB_COV_INT_EN | \
79 IMX7D_REG_ADC_INT_CHC_COV_INT_EN | \
80 IMX7D_REG_ADC_INT_CHD_COV_INT_EN)
81 #define IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS 0xf00
82 #define IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT 0xf0000
84 #define IMX7D_ADC_TIMEOUT msecs_to_jiffies(100)
86 enum imx7d_adc_clk_pre_div
{
87 IMX7D_ADC_ANALOG_CLK_PRE_DIV_4
,
88 IMX7D_ADC_ANALOG_CLK_PRE_DIV_8
,
89 IMX7D_ADC_ANALOG_CLK_PRE_DIV_16
,
90 IMX7D_ADC_ANALOG_CLK_PRE_DIV_32
,
91 IMX7D_ADC_ANALOG_CLK_PRE_DIV_64
,
92 IMX7D_ADC_ANALOG_CLK_PRE_DIV_128
,
95 enum imx7d_adc_average_num
{
96 IMX7D_ADC_AVERAGE_NUM_4
,
97 IMX7D_ADC_AVERAGE_NUM_8
,
98 IMX7D_ADC_AVERAGE_NUM_16
,
99 IMX7D_ADC_AVERAGE_NUM_32
,
102 struct imx7d_adc_feature
{
103 enum imx7d_adc_clk_pre_div clk_pre_div
;
104 enum imx7d_adc_average_num avg_num
;
106 u32 core_time_unit
; /* impact the sample rate */
121 struct regulator
*vref
;
122 struct imx7d_adc_feature adc_feature
;
124 struct completion completion
;
127 struct imx7d_adc_analogue_core_clk
{
132 #define IMX7D_ADC_ANALOGUE_CLK_CONFIG(_pre_div, _reg_conf) { \
133 .pre_div = (_pre_div), \
134 .reg_config = (_reg_conf), \
137 static const struct imx7d_adc_analogue_core_clk imx7d_adc_analogue_clk
[] = {
138 IMX7D_ADC_ANALOGUE_CLK_CONFIG(4, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_4
),
139 IMX7D_ADC_ANALOGUE_CLK_CONFIG(8, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_8
),
140 IMX7D_ADC_ANALOGUE_CLK_CONFIG(16, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_16
),
141 IMX7D_ADC_ANALOGUE_CLK_CONFIG(32, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_32
),
142 IMX7D_ADC_ANALOGUE_CLK_CONFIG(64, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_64
),
143 IMX7D_ADC_ANALOGUE_CLK_CONFIG(128, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_128
),
146 #define IMX7D_ADC_CHAN(_idx) { \
147 .type = IIO_VOLTAGE, \
150 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
151 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
152 BIT(IIO_CHAN_INFO_SAMP_FREQ), \
155 static const struct iio_chan_spec imx7d_adc_iio_channels
[] = {
174 static const u32 imx7d_adc_average_num
[] = {
175 IMX7D_REG_ADC_CH_CFG2_AVG_NUM_4
,
176 IMX7D_REG_ADC_CH_CFG2_AVG_NUM_8
,
177 IMX7D_REG_ADC_CH_CFG2_AVG_NUM_16
,
178 IMX7D_REG_ADC_CH_CFG2_AVG_NUM_32
,
181 static void imx7d_adc_feature_config(struct imx7d_adc
*info
)
183 info
->adc_feature
.clk_pre_div
= IMX7D_ADC_ANALOG_CLK_PRE_DIV_4
;
184 info
->adc_feature
.avg_num
= IMX7D_ADC_AVERAGE_NUM_32
;
185 info
->adc_feature
.core_time_unit
= 1;
186 info
->adc_feature
.average_en
= true;
189 static void imx7d_adc_sample_rate_set(struct imx7d_adc
*info
)
191 struct imx7d_adc_feature
*adc_feature
= &info
->adc_feature
;
192 struct imx7d_adc_analogue_core_clk adc_analogure_clk
;
198 * Before sample set, disable channel A,B,C,D. Here we
199 * clear the bit 31 of register REG_ADC_CH_A\B\C\D_CFG1.
201 for (i
= 0; i
< 4; i
++) {
203 readl(info
->regs
+ i
* IMX7D_EACH_CHANNEL_REG_OFFSET
);
204 tmp_cfg1
&= ~IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN
;
206 info
->regs
+ i
* IMX7D_EACH_CHANNEL_REG_OFFSET
);
209 adc_analogure_clk
= imx7d_adc_analogue_clk
[adc_feature
->clk_pre_div
];
210 sample_rate
|= adc_analogure_clk
.reg_config
;
211 info
->pre_div_num
= adc_analogure_clk
.pre_div
;
213 sample_rate
|= adc_feature
->core_time_unit
;
214 writel(sample_rate
, info
->regs
+ IMX7D_REG_ADC_TIMER_UNIT
);
217 static void imx7d_adc_hw_init(struct imx7d_adc
*info
)
221 /* power up and enable adc analogue core */
222 cfg
= readl(info
->regs
+ IMX7D_REG_ADC_ADC_CFG
);
223 cfg
&= ~(IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN
|
224 IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN
);
225 cfg
|= IMX7D_REG_ADC_ADC_CFG_ADC_EN
;
226 writel(cfg
, info
->regs
+ IMX7D_REG_ADC_ADC_CFG
);
228 /* enable channel A,B,C,D interrupt */
229 writel(IMX7D_REG_ADC_INT_CHANNEL_INT_EN
,
230 info
->regs
+ IMX7D_REG_ADC_INT_SIG_EN
);
231 writel(IMX7D_REG_ADC_INT_CHANNEL_INT_EN
,
232 info
->regs
+ IMX7D_REG_ADC_INT_EN
);
234 imx7d_adc_sample_rate_set(info
);
237 static void imx7d_adc_channel_set(struct imx7d_adc
*info
)
243 channel
= info
->channel
;
245 /* the channel choose single conversion, and enable average mode */
246 cfg1
|= (IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN
|
247 IMX7D_REG_ADC_CH_CFG1_CHANNEL_SINGLE
);
248 if (info
->adc_feature
.average_en
)
249 cfg1
|= IMX7D_REG_ADC_CH_CFG1_CHANNEL_AVG_EN
;
252 * physical channel 0 chose logical channel A
253 * physical channel 1 chose logical channel B
254 * physical channel 2 chose logical channel C
255 * physical channel 3 chose logical channel D
257 cfg1
|= IMX7D_REG_ADC_CH_CFG1_CHANNEL_SEL(channel
);
260 * read register REG_ADC_CH_A\B\C\D_CFG2, according to the
263 cfg2
= readl(info
->regs
+ IMX7D_EACH_CHANNEL_REG_OFFSET
* channel
+
264 IMX7D_REG_ADC_CHANNEL_CFG2_BASE
);
266 cfg2
|= imx7d_adc_average_num
[info
->adc_feature
.avg_num
];
269 * write the register REG_ADC_CH_A\B\C\D_CFG2, according to
272 writel(cfg2
, info
->regs
+ IMX7D_EACH_CHANNEL_REG_OFFSET
* channel
+
273 IMX7D_REG_ADC_CHANNEL_CFG2_BASE
);
274 writel(cfg1
, info
->regs
+ IMX7D_EACH_CHANNEL_REG_OFFSET
* channel
);
277 static u32
imx7d_adc_get_sample_rate(struct imx7d_adc
*info
)
279 /* input clock is always 24MHz */
280 u32 input_clk
= 24000000;
281 u32 analogue_core_clk
;
282 u32 core_time_unit
= info
->adc_feature
.core_time_unit
;
285 analogue_core_clk
= input_clk
/ info
->pre_div_num
;
286 tmp
= (core_time_unit
+ 1) * 6;
288 return analogue_core_clk
/ tmp
;
291 static int imx7d_adc_read_raw(struct iio_dev
*indio_dev
,
292 struct iio_chan_spec
const *chan
,
297 struct imx7d_adc
*info
= iio_priv(indio_dev
);
303 case IIO_CHAN_INFO_RAW
:
304 mutex_lock(&indio_dev
->mlock
);
305 reinit_completion(&info
->completion
);
307 channel
= chan
->channel
& 0x03;
308 info
->channel
= channel
;
309 imx7d_adc_channel_set(info
);
311 ret
= wait_for_completion_interruptible_timeout
312 (&info
->completion
, IMX7D_ADC_TIMEOUT
);
314 mutex_unlock(&indio_dev
->mlock
);
318 mutex_unlock(&indio_dev
->mlock
);
323 mutex_unlock(&indio_dev
->mlock
);
326 case IIO_CHAN_INFO_SCALE
:
327 info
->vref_uv
= regulator_get_voltage(info
->vref
);
328 *val
= info
->vref_uv
/ 1000;
330 return IIO_VAL_FRACTIONAL_LOG2
;
332 case IIO_CHAN_INFO_SAMP_FREQ
:
333 *val
= imx7d_adc_get_sample_rate(info
);
341 static int imx7d_adc_read_data(struct imx7d_adc
*info
)
346 channel
= info
->channel
& 0x03;
349 * channel A and B conversion result share one register,
350 * bit[27~16] is the channel B conversion result,
351 * bit[11~0] is the channel A conversion result.
352 * channel C and D is the same.
355 value
= readl(info
->regs
+ IMX7D_REG_ADC_CHA_B_CNV_RSLT
);
357 value
= readl(info
->regs
+ IMX7D_REG_ADC_CHC_D_CNV_RSLT
);
358 if (channel
& 0x1) /* channel B or D */
359 value
= (value
>> 16) & 0xFFF;
360 else /* channel A or C */
366 static irqreturn_t
imx7d_adc_isr(int irq
, void *dev_id
)
368 struct imx7d_adc
*info
= (struct imx7d_adc
*)dev_id
;
371 status
= readl(info
->regs
+ IMX7D_REG_ADC_INT_STATUS
);
372 if (status
& IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS
) {
373 info
->value
= imx7d_adc_read_data(info
);
374 complete(&info
->completion
);
377 * The register IMX7D_REG_ADC_INT_STATUS can't clear
378 * itself after read operation, need software to write
379 * 0 to the related bit. Here we clear the channel A/B/C/D
380 * conversion finished flag.
382 status
&= ~IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS
;
383 writel(status
, info
->regs
+ IMX7D_REG_ADC_INT_STATUS
);
387 * If the channel A/B/C/D conversion timeout, report it and clear these
390 if (status
& IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT
) {
391 pr_err("%s: ADC got conversion time out interrupt: 0x%08x\n",
392 dev_name(info
->dev
), status
);
393 status
&= ~IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT
;
394 writel(status
, info
->regs
+ IMX7D_REG_ADC_INT_STATUS
);
400 static int imx7d_adc_reg_access(struct iio_dev
*indio_dev
,
401 unsigned reg
, unsigned writeval
,
404 struct imx7d_adc
*info
= iio_priv(indio_dev
);
406 if (!readval
|| reg
% 4 || reg
> IMX7D_REG_ADC_ADC_CFG
)
409 *readval
= readl(info
->regs
+ reg
);
414 static const struct iio_info imx7d_adc_iio_info
= {
415 .driver_module
= THIS_MODULE
,
416 .read_raw
= &imx7d_adc_read_raw
,
417 .debugfs_reg_access
= &imx7d_adc_reg_access
,
420 static const struct of_device_id imx7d_adc_match
[] = {
421 { .compatible
= "fsl,imx7d-adc", },
424 MODULE_DEVICE_TABLE(of
, imx7d_adc_match
);
426 static void imx7d_adc_power_down(struct imx7d_adc
*info
)
430 adc_cfg
= readl(info
->regs
+ IMX7D_REG_ADC_ADC_CFG
);
431 adc_cfg
|= IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN
|
432 IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN
;
433 adc_cfg
&= ~IMX7D_REG_ADC_ADC_CFG_ADC_EN
;
434 writel(adc_cfg
, info
->regs
+ IMX7D_REG_ADC_ADC_CFG
);
437 static int imx7d_adc_probe(struct platform_device
*pdev
)
439 struct imx7d_adc
*info
;
440 struct iio_dev
*indio_dev
;
441 struct resource
*mem
;
445 indio_dev
= devm_iio_device_alloc(&pdev
->dev
, sizeof(*info
));
447 dev_err(&pdev
->dev
, "Failed allocating iio device\n");
451 info
= iio_priv(indio_dev
);
452 info
->dev
= &pdev
->dev
;
454 mem
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
455 info
->regs
= devm_ioremap_resource(&pdev
->dev
, mem
);
456 if (IS_ERR(info
->regs
)) {
457 ret
= PTR_ERR(info
->regs
);
459 "Failed to remap adc memory, err = %d\n", ret
);
463 irq
= platform_get_irq(pdev
, 0);
465 dev_err(&pdev
->dev
, "No irq resource?\n");
469 info
->clk
= devm_clk_get(&pdev
->dev
, "adc");
470 if (IS_ERR(info
->clk
)) {
471 ret
= PTR_ERR(info
->clk
);
472 dev_err(&pdev
->dev
, "Failed getting clock, err = %d\n", ret
);
476 info
->vref
= devm_regulator_get(&pdev
->dev
, "vref");
477 if (IS_ERR(info
->vref
)) {
478 ret
= PTR_ERR(info
->vref
);
480 "Failed getting reference voltage, err = %d\n", ret
);
484 ret
= regulator_enable(info
->vref
);
487 "Can't enable adc reference top voltage, err = %d\n",
492 platform_set_drvdata(pdev
, indio_dev
);
494 init_completion(&info
->completion
);
496 indio_dev
->name
= dev_name(&pdev
->dev
);
497 indio_dev
->dev
.parent
= &pdev
->dev
;
498 indio_dev
->info
= &imx7d_adc_iio_info
;
499 indio_dev
->modes
= INDIO_DIRECT_MODE
;
500 indio_dev
->channels
= imx7d_adc_iio_channels
;
501 indio_dev
->num_channels
= ARRAY_SIZE(imx7d_adc_iio_channels
);
503 ret
= clk_prepare_enable(info
->clk
);
506 "Could not prepare or enable the clock.\n");
507 goto error_adc_clk_enable
;
510 ret
= devm_request_irq(info
->dev
, irq
,
512 dev_name(&pdev
->dev
), info
);
514 dev_err(&pdev
->dev
, "Failed requesting irq, irq = %d\n", irq
);
515 goto error_iio_device_register
;
518 imx7d_adc_feature_config(info
);
519 imx7d_adc_hw_init(info
);
521 ret
= iio_device_register(indio_dev
);
523 imx7d_adc_power_down(info
);
524 dev_err(&pdev
->dev
, "Couldn't register the device.\n");
525 goto error_iio_device_register
;
530 error_iio_device_register
:
531 clk_disable_unprepare(info
->clk
);
532 error_adc_clk_enable
:
533 regulator_disable(info
->vref
);
538 static int imx7d_adc_remove(struct platform_device
*pdev
)
540 struct iio_dev
*indio_dev
= platform_get_drvdata(pdev
);
541 struct imx7d_adc
*info
= iio_priv(indio_dev
);
543 iio_device_unregister(indio_dev
);
545 imx7d_adc_power_down(info
);
547 clk_disable_unprepare(info
->clk
);
548 regulator_disable(info
->vref
);
553 static int __maybe_unused
imx7d_adc_suspend(struct device
*dev
)
555 struct iio_dev
*indio_dev
= dev_get_drvdata(dev
);
556 struct imx7d_adc
*info
= iio_priv(indio_dev
);
558 imx7d_adc_power_down(info
);
560 clk_disable_unprepare(info
->clk
);
561 regulator_disable(info
->vref
);
566 static int __maybe_unused
imx7d_adc_resume(struct device
*dev
)
568 struct iio_dev
*indio_dev
= dev_get_drvdata(dev
);
569 struct imx7d_adc
*info
= iio_priv(indio_dev
);
572 ret
= regulator_enable(info
->vref
);
575 "Can't enable adc reference top voltage, err = %d\n",
580 ret
= clk_prepare_enable(info
->clk
);
583 "Could not prepare or enable clock.\n");
584 regulator_disable(info
->vref
);
588 imx7d_adc_hw_init(info
);
593 static SIMPLE_DEV_PM_OPS(imx7d_adc_pm_ops
, imx7d_adc_suspend
, imx7d_adc_resume
);
595 static struct platform_driver imx7d_adc_driver
= {
596 .probe
= imx7d_adc_probe
,
597 .remove
= imx7d_adc_remove
,
600 .of_match_table
= imx7d_adc_match
,
601 .pm
= &imx7d_adc_pm_ops
,
605 module_platform_driver(imx7d_adc_driver
);
607 MODULE_AUTHOR("Haibo Chen <haibo.chen@freescale.com>");
608 MODULE_DESCRIPTION("Freeacale IMX7D ADC driver");
609 MODULE_LICENSE("GPL v2");