// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Freescale i.MX7D ADC driver
*
* Copyright (C) 2015 Freescale Semiconductor, Inc.
*/
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/iio/iio.h>
#include <linux/iio/driver.h>
#include <linux/iio/sysfs.h>
/* ADC register */
#define IMX7D_REG_ADC_CH_A_CFG1 0x00
#define IMX7D_REG_ADC_CH_A_CFG2 0x10
#define IMX7D_REG_ADC_CH_B_CFG1 0x20
#define IMX7D_REG_ADC_CH_B_CFG2 0x30
#define IMX7D_REG_ADC_CH_C_CFG1 0x40
#define IMX7D_REG_ADC_CH_C_CFG2 0x50
#define IMX7D_REG_ADC_CH_D_CFG1 0x60
#define IMX7D_REG_ADC_CH_D_CFG2 0x70
#define IMX7D_REG_ADC_CH_SW_CFG 0x80
#define IMX7D_REG_ADC_TIMER_UNIT 0x90
#define IMX7D_REG_ADC_DMA_FIFO 0xa0
#define IMX7D_REG_ADC_FIFO_STATUS 0xb0
#define IMX7D_REG_ADC_INT_SIG_EN 0xc0
#define IMX7D_REG_ADC_INT_EN 0xd0
#define IMX7D_REG_ADC_INT_STATUS 0xe0
#define IMX7D_REG_ADC_CHA_B_CNV_RSLT 0xf0
#define IMX7D_REG_ADC_CHC_D_CNV_RSLT 0x100
#define IMX7D_REG_ADC_CH_SW_CNV_RSLT 0x110
#define IMX7D_REG_ADC_DMA_FIFO_DAT 0x120
#define IMX7D_REG_ADC_ADC_CFG 0x130
#define IMX7D_REG_ADC_CHANNEL_CFG2_BASE 0x10
#define IMX7D_EACH_CHANNEL_REG_OFFSET 0x20
#define IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN (0x1 << 31)
#define IMX7D_REG_ADC_CH_CFG1_CHANNEL_SINGLE BIT(30)
#define IMX7D_REG_ADC_CH_CFG1_CHANNEL_AVG_EN BIT(29)
#define IMX7D_REG_ADC_CH_CFG1_CHANNEL_SEL(x) ((x) << 24)
#define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_4 (0x0 << 12)
#define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_8 (0x1 << 12)
#define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_16 (0x2 << 12)
#define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_32 (0x3 << 12)
#define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_4 (0x0 << 29)
#define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_8 (0x1 << 29)
#define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_16 (0x2 << 29)
#define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_32 (0x3 << 29)
#define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_64 (0x4 << 29)
#define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_128 (0x5 << 29)
#define IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN BIT(31)
#define IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN BIT(1)
#define IMX7D_REG_ADC_ADC_CFG_ADC_EN BIT(0)
#define IMX7D_REG_ADC_INT_CHA_COV_INT_EN BIT(8)
#define IMX7D_REG_ADC_INT_CHB_COV_INT_EN BIT(9)
#define IMX7D_REG_ADC_INT_CHC_COV_INT_EN BIT(10)
#define IMX7D_REG_ADC_INT_CHD_COV_INT_EN BIT(11)
#define IMX7D_REG_ADC_INT_CHANNEL_INT_EN \
(IMX7D_REG_ADC_INT_CHA_COV_INT_EN | \
IMX7D_REG_ADC_INT_CHB_COV_INT_EN | \
IMX7D_REG_ADC_INT_CHC_COV_INT_EN | \
IMX7D_REG_ADC_INT_CHD_COV_INT_EN)
#define IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS 0xf00
#define IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT 0xf0000
#define IMX7D_ADC_TIMEOUT msecs_to_jiffies(100)
#define IMX7D_ADC_INPUT_CLK 24000000
enum imx7d_adc_clk_pre_div {
IMX7D_ADC_ANALOG_CLK_PRE_DIV_4,
IMX7D_ADC_ANALOG_CLK_PRE_DIV_8,
IMX7D_ADC_ANALOG_CLK_PRE_DIV_16,
IMX7D_ADC_ANALOG_CLK_PRE_DIV_32,
IMX7D_ADC_ANALOG_CLK_PRE_DIV_64,
IMX7D_ADC_ANALOG_CLK_PRE_DIV_128,
};
enum imx7d_adc_average_num {
IMX7D_ADC_AVERAGE_NUM_4,
IMX7D_ADC_AVERAGE_NUM_8,
IMX7D_ADC_AVERAGE_NUM_16,
IMX7D_ADC_AVERAGE_NUM_32,
};
struct imx7d_adc_feature {
enum imx7d_adc_clk_pre_div clk_pre_div;
enum imx7d_adc_average_num avg_num;
u32 core_time_unit; /* impact the sample rate */
};
struct imx7d_adc {
struct device *dev;
void __iomem *regs;
struct clk *clk;
/* lock to protect against multiple access to the device */
struct mutex lock;
u32 vref_uv;
u32 value;
u32 channel;
u32 pre_div_num;
struct regulator *vref;
struct imx7d_adc_feature adc_feature;
struct completion completion;
};
struct imx7d_adc_analogue_core_clk {
u32 pre_div;
u32 reg_config;
};
#define IMX7D_ADC_ANALOGUE_CLK_CONFIG(_pre_div, _reg_conf) { \
.pre_div = (_pre_div), \
.reg_config = (_reg_conf), \
}
static const struct imx7d_adc_analogue_core_clk imx7d_adc_analogue_clk[] = {
IMX7D_ADC_ANALOGUE_CLK_CONFIG(4, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_4),
IMX7D_ADC_ANALOGUE_CLK_CONFIG(8, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_8),
IMX7D_ADC_ANALOGUE_CLK_CONFIG(16, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_16),
IMX7D_ADC_ANALOGUE_CLK_CONFIG(32, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_32),
IMX7D_ADC_ANALOGUE_CLK_CONFIG(64, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_64),
IMX7D_ADC_ANALOGUE_CLK_CONFIG(128, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_128),
};
#define IMX7D_ADC_CHAN(_idx) { \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.channel = (_idx), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
BIT(IIO_CHAN_INFO_SAMP_FREQ), \
}
static const struct iio_chan_spec imx7d_adc_iio_channels[] = {
IMX7D_ADC_CHAN(0),
IMX7D_ADC_CHAN(1),
IMX7D_ADC_CHAN(2),
IMX7D_ADC_CHAN(3),
IMX7D_ADC_CHAN(4),
IMX7D_ADC_CHAN(5),
IMX7D_ADC_CHAN(6),
IMX7D_ADC_CHAN(7),
IMX7D_ADC_CHAN(8),
IMX7D_ADC_CHAN(9),
IMX7D_ADC_CHAN(10),
IMX7D_ADC_CHAN(11),
IMX7D_ADC_CHAN(12),
IMX7D_ADC_CHAN(13),
IMX7D_ADC_CHAN(14),
IMX7D_ADC_CHAN(15),
};
static const u32 imx7d_adc_average_num[] = {
IMX7D_REG_ADC_CH_CFG2_AVG_NUM_4,
IMX7D_REG_ADC_CH_CFG2_AVG_NUM_8,
IMX7D_REG_ADC_CH_CFG2_AVG_NUM_16,
IMX7D_REG_ADC_CH_CFG2_AVG_NUM_32,
};
static void imx7d_adc_feature_config(struct imx7d_adc *info)
{
info->adc_feature.clk_pre_div = IMX7D_ADC_ANALOG_CLK_PRE_DIV_4;
info->adc_feature.avg_num = IMX7D_ADC_AVERAGE_NUM_32;
info->adc_feature.core_time_unit = 1;
}
static void imx7d_adc_sample_rate_set(struct imx7d_adc *info)
{
struct imx7d_adc_feature *adc_feature = &info->adc_feature;
struct imx7d_adc_analogue_core_clk adc_analogure_clk;
u32 i;
u32 tmp_cfg1;
u32 sample_rate = 0;
/*
* Before sample set, disable channel A,B,C,D. Here we
* clear the bit 31 of register REG_ADC_CH_A\B\C\D_CFG1.
*/
for (i = 0; i < 4; i++) {
tmp_cfg1 =
readl(info->regs + i * IMX7D_EACH_CHANNEL_REG_OFFSET);
tmp_cfg1 &= ~IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN;
writel(tmp_cfg1,
info->regs + i * IMX7D_EACH_CHANNEL_REG_OFFSET);
}
adc_analogure_clk = imx7d_adc_analogue_clk[adc_feature->clk_pre_div];
sample_rate |= adc_analogure_clk.reg_config;
info->pre_div_num = adc_analogure_clk.pre_div;
sample_rate |= adc_feature->core_time_unit;
writel(sample_rate, info->regs + IMX7D_REG_ADC_TIMER_UNIT);
}
static void imx7d_adc_hw_init(struct imx7d_adc *info)
{
u32 cfg;
/* power up and enable adc analogue core */
cfg = readl(info->regs + IMX7D_REG_ADC_ADC_CFG);
cfg &= ~(IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN |
IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN);
cfg |= IMX7D_REG_ADC_ADC_CFG_ADC_EN;
writel(cfg, info->regs + IMX7D_REG_ADC_ADC_CFG);
/* enable channel A,B,C,D interrupt */
writel(IMX7D_REG_ADC_INT_CHANNEL_INT_EN,
info->regs + IMX7D_REG_ADC_INT_SIG_EN);
writel(IMX7D_REG_ADC_INT_CHANNEL_INT_EN,
info->regs + IMX7D_REG_ADC_INT_EN);
imx7d_adc_sample_rate_set(info);
}
static void imx7d_adc_channel_set(struct imx7d_adc *info)
{
u32 cfg1 = 0;
u32 cfg2;
u32 channel;
channel = info->channel;
/* the channel choose single conversion, and enable average mode */
cfg1 |= (IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN |
IMX7D_REG_ADC_CH_CFG1_CHANNEL_SINGLE |
IMX7D_REG_ADC_CH_CFG1_CHANNEL_AVG_EN);
/*
* physical channel 0 chose logical channel A
* physical channel 1 chose logical channel B
* physical channel 2 chose logical channel C
* physical channel 3 chose logical channel D
*/
cfg1 |= IMX7D_REG_ADC_CH_CFG1_CHANNEL_SEL(channel);
/*
* read register REG_ADC_CH_A\B\C\D_CFG2, according to the
* channel chosen
*/
cfg2 = readl(info->regs + IMX7D_EACH_CHANNEL_REG_OFFSET * channel +
IMX7D_REG_ADC_CHANNEL_CFG2_BASE);
cfg2 |= imx7d_adc_average_num[info->adc_feature.avg_num];
/*
* write the register REG_ADC_CH_A\B\C\D_CFG2, according to
* the channel chosen
*/
writel(cfg2, info->regs + IMX7D_EACH_CHANNEL_REG_OFFSET * channel +
IMX7D_REG_ADC_CHANNEL_CFG2_BASE);
writel(cfg1, info->regs + IMX7D_EACH_CHANNEL_REG_OFFSET * channel);
}
static u32 imx7d_adc_get_sample_rate(struct imx7d_adc *info)
{
u32 analogue_core_clk;
u32 core_time_unit = info->adc_feature.core_time_unit;
u32 tmp;
analogue_core_clk = IMX7D_ADC_INPUT_CLK / info->pre_div_num;
tmp = (core_time_unit + 1) * 6;
return analogue_core_clk / tmp;
}
static int imx7d_adc_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long mask)
{
struct imx7d_adc *info = iio_priv(indio_dev);
u32 channel;
long ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
mutex_lock(&info->lock);
reinit_completion(&info->completion);
channel = chan->channel & 0x03;
info->channel = channel;
imx7d_adc_channel_set(info);
ret = wait_for_completion_interruptible_timeout
(&info->completion, IMX7D_ADC_TIMEOUT);
if (ret == 0) {
mutex_unlock(&info->lock);
return -ETIMEDOUT;
}
if (ret < 0) {
mutex_unlock(&info->lock);
return ret;
}
*val = info->value;
mutex_unlock(&info->lock);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
info->vref_uv = regulator_get_voltage(info->vref);
*val = info->vref_uv / 1000;
*val2 = 12;
return IIO_VAL_FRACTIONAL_LOG2;
case IIO_CHAN_INFO_SAMP_FREQ:
*val = imx7d_adc_get_sample_rate(info);
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static int imx7d_adc_read_data(struct imx7d_adc *info)
{
u32 channel;
u32 value;
channel = info->channel & 0x03;
/*
* channel A and B conversion result share one register,
* bit[27~16] is the channel B conversion result,
* bit[11~0] is the channel A conversion result.
* channel C and D is the same.
*/
if (channel < 2)
value = readl(info->regs + IMX7D_REG_ADC_CHA_B_CNV_RSLT);
else
value = readl(info->regs + IMX7D_REG_ADC_CHC_D_CNV_RSLT);
if (channel & 0x1) /* channel B or D */
value = (value >> 16) & 0xFFF;
else /* channel A or C */
value &= 0xFFF;
return value;
}
static irqreturn_t imx7d_adc_isr(int irq, void *dev_id)
{
struct imx7d_adc *info = dev_id;
int status;
status = readl(info->regs + IMX7D_REG_ADC_INT_STATUS);
if (status & IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS) {
info->value = imx7d_adc_read_data(info);
complete(&info->completion);
/*
* The register IMX7D_REG_ADC_INT_STATUS can't clear
* itself after read operation, need software to write
* 0 to the related bit. Here we clear the channel A/B/C/D
* conversion finished flag.
*/
status &= ~IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS;
writel(status, info->regs + IMX7D_REG_ADC_INT_STATUS);
}
/*
* If the channel A/B/C/D conversion timeout, report it and clear these
* timeout flags.
*/
if (status & IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT) {
dev_err(info->dev,
"ADC got conversion time out interrupt: 0x%08x\n",
status);
status &= ~IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT;
writel(status, info->regs + IMX7D_REG_ADC_INT_STATUS);
}
return IRQ_HANDLED;
}
static int imx7d_adc_reg_access(struct iio_dev *indio_dev,
unsigned reg, unsigned writeval,
unsigned *readval)
{
struct imx7d_adc *info = iio_priv(indio_dev);
if (!readval || reg % 4 || reg > IMX7D_REG_ADC_ADC_CFG)
return -EINVAL;
*readval = readl(info->regs + reg);
return 0;
}
static const struct iio_info imx7d_adc_iio_info = {
.read_raw = &imx7d_adc_read_raw,
.debugfs_reg_access = &imx7d_adc_reg_access,
};
static const struct of_device_id imx7d_adc_match[] = {
{ .compatible = "fsl,imx7d-adc", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, imx7d_adc_match);
static void imx7d_adc_power_down(struct imx7d_adc *info)
{
u32 adc_cfg;
adc_cfg = readl(info->regs + IMX7D_REG_ADC_ADC_CFG);
adc_cfg |= IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN |
IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN;
adc_cfg &= ~IMX7D_REG_ADC_ADC_CFG_ADC_EN;
writel(adc_cfg, info->regs + IMX7D_REG_ADC_ADC_CFG);
}
static int imx7d_adc_enable(struct device *dev)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct imx7d_adc *info = iio_priv(indio_dev);
int ret;
ret = regulator_enable(info->vref);
if (ret) {
dev_err(info->dev,
"Can't enable adc reference top voltage, err = %d\n",
ret);
return ret;
}
ret = clk_prepare_enable(info->clk);
if (ret) {
dev_err(info->dev,
"Could not prepare or enable clock.\n");
regulator_disable(info->vref);
return ret;
}
imx7d_adc_hw_init(info);
return 0;
}
static int imx7d_adc_disable(struct device *dev)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct imx7d_adc *info = iio_priv(indio_dev);
imx7d_adc_power_down(info);
clk_disable_unprepare(info->clk);
regulator_disable(info->vref);
return 0;
}
static void __imx7d_adc_disable(void *data)
{
imx7d_adc_disable(data);
}
static int imx7d_adc_probe(struct platform_device *pdev)
{
struct imx7d_adc *info;
struct iio_dev *indio_dev;
struct device *dev = &pdev->dev;
int irq;
int ret;
indio_dev = devm_iio_device_alloc(dev, sizeof(*info));
if (!indio_dev) {
dev_err(&pdev->dev, "Failed allocating iio device\n");
return -ENOMEM;
}
info = iio_priv(indio_dev);
info->dev = dev;
info->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(info->regs))
return PTR_ERR(info->regs);
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
info->clk = devm_clk_get(dev, "adc");
if (IS_ERR(info->clk))
return dev_err_probe(dev, PTR_ERR(info->clk), "Failed getting clock\n");
info->vref = devm_regulator_get(dev, "vref");
if (IS_ERR(info->vref))
return dev_err_probe(dev, PTR_ERR(info->vref),
"Failed getting reference voltage\n");
platform_set_drvdata(pdev, indio_dev);
init_completion(&info->completion);
indio_dev->name = dev_name(dev);
indio_dev->info = &imx7d_adc_iio_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = imx7d_adc_iio_channels;
indio_dev->num_channels = ARRAY_SIZE(imx7d_adc_iio_channels);
ret = devm_request_irq(dev, irq, imx7d_adc_isr, 0, dev_name(dev), info);
if (ret < 0) {
dev_err(dev, "Failed requesting irq, irq = %d\n", irq);
return ret;
}
imx7d_adc_feature_config(info);
ret = imx7d_adc_enable(dev);
if (ret)
return ret;
ret = devm_add_action_or_reset(dev, __imx7d_adc_disable, dev);
if (ret)
return ret;
mutex_init(&info->lock);
ret = devm_iio_device_register(dev, indio_dev);
if (ret) {
dev_err(&pdev->dev, "Couldn't register the device.\n");
return ret;
}
return 0;
}
static DEFINE_SIMPLE_DEV_PM_OPS(imx7d_adc_pm_ops, imx7d_adc_disable,
imx7d_adc_enable);
static struct platform_driver imx7d_adc_driver = {
.probe = imx7d_adc_probe,
.driver = {
.name = "imx7d_adc",
.of_match_table = imx7d_adc_match,
.pm = pm_sleep_ptr(&imx7d_adc_pm_ops),
},
};
module_platform_driver(imx7d_adc_driver);
MODULE_AUTHOR("Haibo Chen <[email protected]>");
MODULE_DESCRIPTION("Freescale IMX7D ADC driver");
MODULE_LICENSE("GPL v2");
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