1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Freescale i.MX7D ADC driver
5 * Copyright (C) 2015 Freescale Semiconductor, Inc.
9 #include <linux/completion.h>
10 #include <linux/err.h>
11 #include <linux/interrupt.h>
13 #include <linux/kernel.h>
14 #include <linux/mod_devicetable.h>
15 #include <linux/module.h>
16 #include <linux/mutex.h>
17 #include <linux/platform_device.h>
18 #include <linux/regulator/consumer.h>
20 #include <linux/iio/iio.h>
21 #include <linux/iio/driver.h>
22 #include <linux/iio/sysfs.h>
25 #define IMX7D_REG_ADC_CH_A_CFG1 0x00
26 #define IMX7D_REG_ADC_CH_A_CFG2 0x10
27 #define IMX7D_REG_ADC_CH_B_CFG1 0x20
28 #define IMX7D_REG_ADC_CH_B_CFG2 0x30
29 #define IMX7D_REG_ADC_CH_C_CFG1 0x40
30 #define IMX7D_REG_ADC_CH_C_CFG2 0x50
31 #define IMX7D_REG_ADC_CH_D_CFG1 0x60
32 #define IMX7D_REG_ADC_CH_D_CFG2 0x70
33 #define IMX7D_REG_ADC_CH_SW_CFG 0x80
34 #define IMX7D_REG_ADC_TIMER_UNIT 0x90
35 #define IMX7D_REG_ADC_DMA_FIFO 0xa0
36 #define IMX7D_REG_ADC_FIFO_STATUS 0xb0
37 #define IMX7D_REG_ADC_INT_SIG_EN 0xc0
38 #define IMX7D_REG_ADC_INT_EN 0xd0
39 #define IMX7D_REG_ADC_INT_STATUS 0xe0
40 #define IMX7D_REG_ADC_CHA_B_CNV_RSLT 0xf0
41 #define IMX7D_REG_ADC_CHC_D_CNV_RSLT 0x100
42 #define IMX7D_REG_ADC_CH_SW_CNV_RSLT 0x110
43 #define IMX7D_REG_ADC_DMA_FIFO_DAT 0x120
44 #define IMX7D_REG_ADC_ADC_CFG 0x130
46 #define IMX7D_REG_ADC_CHANNEL_CFG2_BASE 0x10
47 #define IMX7D_EACH_CHANNEL_REG_OFFSET 0x20
49 #define IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN (0x1 << 31)
50 #define IMX7D_REG_ADC_CH_CFG1_CHANNEL_SINGLE BIT(30)
51 #define IMX7D_REG_ADC_CH_CFG1_CHANNEL_AVG_EN BIT(29)
52 #define IMX7D_REG_ADC_CH_CFG1_CHANNEL_SEL(x) ((x) << 24)
54 #define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_4 (0x0 << 12)
55 #define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_8 (0x1 << 12)
56 #define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_16 (0x2 << 12)
57 #define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_32 (0x3 << 12)
59 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_4 (0x0 << 29)
60 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_8 (0x1 << 29)
61 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_16 (0x2 << 29)
62 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_32 (0x3 << 29)
63 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_64 (0x4 << 29)
64 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_128 (0x5 << 29)
66 #define IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN BIT(31)
67 #define IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN BIT(1)
68 #define IMX7D_REG_ADC_ADC_CFG_ADC_EN BIT(0)
70 #define IMX7D_REG_ADC_INT_CHA_COV_INT_EN BIT(8)
71 #define IMX7D_REG_ADC_INT_CHB_COV_INT_EN BIT(9)
72 #define IMX7D_REG_ADC_INT_CHC_COV_INT_EN BIT(10)
73 #define IMX7D_REG_ADC_INT_CHD_COV_INT_EN BIT(11)
74 #define IMX7D_REG_ADC_INT_CHANNEL_INT_EN \
75 (IMX7D_REG_ADC_INT_CHA_COV_INT_EN | \
76 IMX7D_REG_ADC_INT_CHB_COV_INT_EN | \
77 IMX7D_REG_ADC_INT_CHC_COV_INT_EN | \
78 IMX7D_REG_ADC_INT_CHD_COV_INT_EN)
79 #define IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS 0xf00
80 #define IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT 0xf0000
82 #define IMX7D_ADC_TIMEOUT msecs_to_jiffies(100)
83 #define IMX7D_ADC_INPUT_CLK 24000000
85 enum imx7d_adc_clk_pre_div
{
86 IMX7D_ADC_ANALOG_CLK_PRE_DIV_4
,
87 IMX7D_ADC_ANALOG_CLK_PRE_DIV_8
,
88 IMX7D_ADC_ANALOG_CLK_PRE_DIV_16
,
89 IMX7D_ADC_ANALOG_CLK_PRE_DIV_32
,
90 IMX7D_ADC_ANALOG_CLK_PRE_DIV_64
,
91 IMX7D_ADC_ANALOG_CLK_PRE_DIV_128
,
94 enum imx7d_adc_average_num
{
95 IMX7D_ADC_AVERAGE_NUM_4
,
96 IMX7D_ADC_AVERAGE_NUM_8
,
97 IMX7D_ADC_AVERAGE_NUM_16
,
98 IMX7D_ADC_AVERAGE_NUM_32
,
101 struct imx7d_adc_feature
{
102 enum imx7d_adc_clk_pre_div clk_pre_div
;
103 enum imx7d_adc_average_num avg_num
;
105 u32 core_time_unit
; /* impact the sample rate */
112 /* lock to protect against multiple access to the device */
119 struct regulator
*vref
;
120 struct imx7d_adc_feature adc_feature
;
122 struct completion completion
;
125 struct imx7d_adc_analogue_core_clk
{
130 #define IMX7D_ADC_ANALOGUE_CLK_CONFIG(_pre_div, _reg_conf) { \
131 .pre_div = (_pre_div), \
132 .reg_config = (_reg_conf), \
135 static const struct imx7d_adc_analogue_core_clk imx7d_adc_analogue_clk
[] = {
136 IMX7D_ADC_ANALOGUE_CLK_CONFIG(4, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_4
),
137 IMX7D_ADC_ANALOGUE_CLK_CONFIG(8, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_8
),
138 IMX7D_ADC_ANALOGUE_CLK_CONFIG(16, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_16
),
139 IMX7D_ADC_ANALOGUE_CLK_CONFIG(32, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_32
),
140 IMX7D_ADC_ANALOGUE_CLK_CONFIG(64, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_64
),
141 IMX7D_ADC_ANALOGUE_CLK_CONFIG(128, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_128
),
144 #define IMX7D_ADC_CHAN(_idx) { \
145 .type = IIO_VOLTAGE, \
148 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
149 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
150 BIT(IIO_CHAN_INFO_SAMP_FREQ), \
153 static const struct iio_chan_spec imx7d_adc_iio_channels
[] = {
172 static const u32 imx7d_adc_average_num
[] = {
173 IMX7D_REG_ADC_CH_CFG2_AVG_NUM_4
,
174 IMX7D_REG_ADC_CH_CFG2_AVG_NUM_8
,
175 IMX7D_REG_ADC_CH_CFG2_AVG_NUM_16
,
176 IMX7D_REG_ADC_CH_CFG2_AVG_NUM_32
,
179 static void imx7d_adc_feature_config(struct imx7d_adc
*info
)
181 info
->adc_feature
.clk_pre_div
= IMX7D_ADC_ANALOG_CLK_PRE_DIV_4
;
182 info
->adc_feature
.avg_num
= IMX7D_ADC_AVERAGE_NUM_32
;
183 info
->adc_feature
.core_time_unit
= 1;
186 static void imx7d_adc_sample_rate_set(struct imx7d_adc
*info
)
188 struct imx7d_adc_feature
*adc_feature
= &info
->adc_feature
;
189 struct imx7d_adc_analogue_core_clk adc_analogure_clk
;
195 * Before sample set, disable channel A,B,C,D. Here we
196 * clear the bit 31 of register REG_ADC_CH_A\B\C\D_CFG1.
198 for (i
= 0; i
< 4; i
++) {
200 readl(info
->regs
+ i
* IMX7D_EACH_CHANNEL_REG_OFFSET
);
201 tmp_cfg1
&= ~IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN
;
203 info
->regs
+ i
* IMX7D_EACH_CHANNEL_REG_OFFSET
);
206 adc_analogure_clk
= imx7d_adc_analogue_clk
[adc_feature
->clk_pre_div
];
207 sample_rate
|= adc_analogure_clk
.reg_config
;
208 info
->pre_div_num
= adc_analogure_clk
.pre_div
;
210 sample_rate
|= adc_feature
->core_time_unit
;
211 writel(sample_rate
, info
->regs
+ IMX7D_REG_ADC_TIMER_UNIT
);
214 static void imx7d_adc_hw_init(struct imx7d_adc
*info
)
218 /* power up and enable adc analogue core */
219 cfg
= readl(info
->regs
+ IMX7D_REG_ADC_ADC_CFG
);
220 cfg
&= ~(IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN
|
221 IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN
);
222 cfg
|= IMX7D_REG_ADC_ADC_CFG_ADC_EN
;
223 writel(cfg
, info
->regs
+ IMX7D_REG_ADC_ADC_CFG
);
225 /* enable channel A,B,C,D interrupt */
226 writel(IMX7D_REG_ADC_INT_CHANNEL_INT_EN
,
227 info
->regs
+ IMX7D_REG_ADC_INT_SIG_EN
);
228 writel(IMX7D_REG_ADC_INT_CHANNEL_INT_EN
,
229 info
->regs
+ IMX7D_REG_ADC_INT_EN
);
231 imx7d_adc_sample_rate_set(info
);
234 static void imx7d_adc_channel_set(struct imx7d_adc
*info
)
240 channel
= info
->channel
;
242 /* the channel choose single conversion, and enable average mode */
243 cfg1
|= (IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN
|
244 IMX7D_REG_ADC_CH_CFG1_CHANNEL_SINGLE
|
245 IMX7D_REG_ADC_CH_CFG1_CHANNEL_AVG_EN
);
248 * physical channel 0 chose logical channel A
249 * physical channel 1 chose logical channel B
250 * physical channel 2 chose logical channel C
251 * physical channel 3 chose logical channel D
253 cfg1
|= IMX7D_REG_ADC_CH_CFG1_CHANNEL_SEL(channel
);
256 * read register REG_ADC_CH_A\B\C\D_CFG2, according to the
259 cfg2
= readl(info
->regs
+ IMX7D_EACH_CHANNEL_REG_OFFSET
* channel
+
260 IMX7D_REG_ADC_CHANNEL_CFG2_BASE
);
262 cfg2
|= imx7d_adc_average_num
[info
->adc_feature
.avg_num
];
265 * write the register REG_ADC_CH_A\B\C\D_CFG2, according to
268 writel(cfg2
, info
->regs
+ IMX7D_EACH_CHANNEL_REG_OFFSET
* channel
+
269 IMX7D_REG_ADC_CHANNEL_CFG2_BASE
);
270 writel(cfg1
, info
->regs
+ IMX7D_EACH_CHANNEL_REG_OFFSET
* channel
);
273 static u32
imx7d_adc_get_sample_rate(struct imx7d_adc
*info
)
275 u32 analogue_core_clk
;
276 u32 core_time_unit
= info
->adc_feature
.core_time_unit
;
279 analogue_core_clk
= IMX7D_ADC_INPUT_CLK
/ info
->pre_div_num
;
280 tmp
= (core_time_unit
+ 1) * 6;
282 return analogue_core_clk
/ tmp
;
285 static int imx7d_adc_read_raw(struct iio_dev
*indio_dev
,
286 struct iio_chan_spec
const *chan
,
291 struct imx7d_adc
*info
= iio_priv(indio_dev
);
297 case IIO_CHAN_INFO_RAW
:
298 mutex_lock(&info
->lock
);
299 reinit_completion(&info
->completion
);
301 channel
= chan
->channel
& 0x03;
302 info
->channel
= channel
;
303 imx7d_adc_channel_set(info
);
305 ret
= wait_for_completion_interruptible_timeout
306 (&info
->completion
, IMX7D_ADC_TIMEOUT
);
308 mutex_unlock(&info
->lock
);
312 mutex_unlock(&info
->lock
);
317 mutex_unlock(&info
->lock
);
320 case IIO_CHAN_INFO_SCALE
:
321 info
->vref_uv
= regulator_get_voltage(info
->vref
);
322 *val
= info
->vref_uv
/ 1000;
324 return IIO_VAL_FRACTIONAL_LOG2
;
326 case IIO_CHAN_INFO_SAMP_FREQ
:
327 *val
= imx7d_adc_get_sample_rate(info
);
335 static int imx7d_adc_read_data(struct imx7d_adc
*info
)
340 channel
= info
->channel
& 0x03;
343 * channel A and B conversion result share one register,
344 * bit[27~16] is the channel B conversion result,
345 * bit[11~0] is the channel A conversion result.
346 * channel C and D is the same.
349 value
= readl(info
->regs
+ IMX7D_REG_ADC_CHA_B_CNV_RSLT
);
351 value
= readl(info
->regs
+ IMX7D_REG_ADC_CHC_D_CNV_RSLT
);
352 if (channel
& 0x1) /* channel B or D */
353 value
= (value
>> 16) & 0xFFF;
354 else /* channel A or C */
360 static irqreturn_t
imx7d_adc_isr(int irq
, void *dev_id
)
362 struct imx7d_adc
*info
= dev_id
;
365 status
= readl(info
->regs
+ IMX7D_REG_ADC_INT_STATUS
);
366 if (status
& IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS
) {
367 info
->value
= imx7d_adc_read_data(info
);
368 complete(&info
->completion
);
371 * The register IMX7D_REG_ADC_INT_STATUS can't clear
372 * itself after read operation, need software to write
373 * 0 to the related bit. Here we clear the channel A/B/C/D
374 * conversion finished flag.
376 status
&= ~IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS
;
377 writel(status
, info
->regs
+ IMX7D_REG_ADC_INT_STATUS
);
381 * If the channel A/B/C/D conversion timeout, report it and clear these
384 if (status
& IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT
) {
386 "ADC got conversion time out interrupt: 0x%08x\n",
388 status
&= ~IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT
;
389 writel(status
, info
->regs
+ IMX7D_REG_ADC_INT_STATUS
);
395 static int imx7d_adc_reg_access(struct iio_dev
*indio_dev
,
396 unsigned reg
, unsigned writeval
,
399 struct imx7d_adc
*info
= iio_priv(indio_dev
);
401 if (!readval
|| reg
% 4 || reg
> IMX7D_REG_ADC_ADC_CFG
)
404 *readval
= readl(info
->regs
+ reg
);
409 static const struct iio_info imx7d_adc_iio_info
= {
410 .read_raw
= &imx7d_adc_read_raw
,
411 .debugfs_reg_access
= &imx7d_adc_reg_access
,
414 static const struct of_device_id imx7d_adc_match
[] = {
415 { .compatible
= "fsl,imx7d-adc", },
418 MODULE_DEVICE_TABLE(of
, imx7d_adc_match
);
420 static void imx7d_adc_power_down(struct imx7d_adc
*info
)
424 adc_cfg
= readl(info
->regs
+ IMX7D_REG_ADC_ADC_CFG
);
425 adc_cfg
|= IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN
|
426 IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN
;
427 adc_cfg
&= ~IMX7D_REG_ADC_ADC_CFG_ADC_EN
;
428 writel(adc_cfg
, info
->regs
+ IMX7D_REG_ADC_ADC_CFG
);
431 static int imx7d_adc_enable(struct device
*dev
)
433 struct iio_dev
*indio_dev
= dev_get_drvdata(dev
);
434 struct imx7d_adc
*info
= iio_priv(indio_dev
);
437 ret
= regulator_enable(info
->vref
);
440 "Can't enable adc reference top voltage, err = %d\n",
445 ret
= clk_prepare_enable(info
->clk
);
448 "Could not prepare or enable clock.\n");
449 regulator_disable(info
->vref
);
453 imx7d_adc_hw_init(info
);
458 static int imx7d_adc_disable(struct device
*dev
)
460 struct iio_dev
*indio_dev
= dev_get_drvdata(dev
);
461 struct imx7d_adc
*info
= iio_priv(indio_dev
);
463 imx7d_adc_power_down(info
);
465 clk_disable_unprepare(info
->clk
);
466 regulator_disable(info
->vref
);
471 static void __imx7d_adc_disable(void *data
)
473 imx7d_adc_disable(data
);
476 static int imx7d_adc_probe(struct platform_device
*pdev
)
478 struct imx7d_adc
*info
;
479 struct iio_dev
*indio_dev
;
480 struct device
*dev
= &pdev
->dev
;
484 indio_dev
= devm_iio_device_alloc(dev
, sizeof(*info
));
486 dev_err(&pdev
->dev
, "Failed allocating iio device\n");
490 info
= iio_priv(indio_dev
);
493 info
->regs
= devm_platform_ioremap_resource(pdev
, 0);
494 if (IS_ERR(info
->regs
))
495 return PTR_ERR(info
->regs
);
497 irq
= platform_get_irq(pdev
, 0);
501 info
->clk
= devm_clk_get(dev
, "adc");
502 if (IS_ERR(info
->clk
))
503 return dev_err_probe(dev
, PTR_ERR(info
->clk
), "Failed getting clock\n");
505 info
->vref
= devm_regulator_get(dev
, "vref");
506 if (IS_ERR(info
->vref
))
507 return dev_err_probe(dev
, PTR_ERR(info
->vref
),
508 "Failed getting reference voltage\n");
510 platform_set_drvdata(pdev
, indio_dev
);
512 init_completion(&info
->completion
);
514 indio_dev
->name
= dev_name(dev
);
515 indio_dev
->info
= &imx7d_adc_iio_info
;
516 indio_dev
->modes
= INDIO_DIRECT_MODE
;
517 indio_dev
->channels
= imx7d_adc_iio_channels
;
518 indio_dev
->num_channels
= ARRAY_SIZE(imx7d_adc_iio_channels
);
520 ret
= devm_request_irq(dev
, irq
, imx7d_adc_isr
, 0, dev_name(dev
), info
);
522 dev_err(dev
, "Failed requesting irq, irq = %d\n", irq
);
526 imx7d_adc_feature_config(info
);
528 ret
= imx7d_adc_enable(dev
);
532 ret
= devm_add_action_or_reset(dev
, __imx7d_adc_disable
, dev
);
536 mutex_init(&info
->lock
);
538 ret
= devm_iio_device_register(dev
, indio_dev
);
540 dev_err(&pdev
->dev
, "Couldn't register the device.\n");
547 static DEFINE_SIMPLE_DEV_PM_OPS(imx7d_adc_pm_ops
, imx7d_adc_disable
,
550 static struct platform_driver imx7d_adc_driver
= {
551 .probe
= imx7d_adc_probe
,
554 .of_match_table
= imx7d_adc_match
,
555 .pm
= pm_sleep_ptr(&imx7d_adc_pm_ops
),
559 module_platform_driver(imx7d_adc_driver
);
561 MODULE_AUTHOR("Haibo Chen <haibo.chen@freescale.com>");
562 MODULE_DESCRIPTION("Freescale IMX7D ADC driver");
563 MODULE_LICENSE("GPL v2");