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alistair23-linux/drivers/iio/adc/sc27xx_adc.c
Freeman Liu 750ac07eb2 iio: adc: sc27xx: Add ADC data conversion timeout 
Sometimes the ADC controller met some problems, and it will not complete
the data conversion, that will can not wake up the read process any more
to block users. So we should add one maximum conversion time to avoid
this issue.

Signed-off-by: Freeman Liu <freeman.liu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2018-11-16 18:32:32 +00:00

611 lines
16 KiB
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Raw Blame History

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Spreadtrum Communications Inc.
#include <linux/hwspinlock.h>
#include <linux/iio/iio.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/nvmem-consumer.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
/* PMIC global registers definition */
#define SC27XX_MODULE_EN 0xc08
#define SC27XX_MODULE_ADC_EN BIT(5)
#define SC27XX_ARM_CLK_EN 0xc10
#define SC27XX_CLK_ADC_EN BIT(5)
#define SC27XX_CLK_ADC_CLK_EN BIT(6)
/* ADC controller registers definition */
#define SC27XX_ADC_CTL 0x0
#define SC27XX_ADC_CH_CFG 0x4
#define SC27XX_ADC_DATA 0x4c
#define SC27XX_ADC_INT_EN 0x50
#define SC27XX_ADC_INT_CLR 0x54
#define SC27XX_ADC_INT_STS 0x58
#define SC27XX_ADC_INT_RAW 0x5c
/* Bits and mask definition for SC27XX_ADC_CTL register */
#define SC27XX_ADC_EN BIT(0)
#define SC27XX_ADC_CHN_RUN BIT(1)
#define SC27XX_ADC_12BIT_MODE BIT(2)
#define SC27XX_ADC_RUN_NUM_MASK GENMASK(7, 4)
#define SC27XX_ADC_RUN_NUM_SHIFT 4
/* Bits and mask definition for SC27XX_ADC_CH_CFG register */
#define SC27XX_ADC_CHN_ID_MASK GENMASK(4, 0)
#define SC27XX_ADC_SCALE_MASK GENMASK(10, 8)
#define SC27XX_ADC_SCALE_SHIFT 8
/* Bits definitions for SC27XX_ADC_INT_EN registers */
#define SC27XX_ADC_IRQ_EN BIT(0)
/* Bits definitions for SC27XX_ADC_INT_CLR registers */
#define SC27XX_ADC_IRQ_CLR BIT(0)
/* Mask definition for SC27XX_ADC_DATA register */
#define SC27XX_ADC_DATA_MASK GENMASK(11, 0)
/* Timeout (ms) for the trylock of hardware spinlocks */
#define SC27XX_ADC_HWLOCK_TIMEOUT 5000
/* Timeout (ms) for ADC data conversion according to ADC datasheet */
#define SC27XX_ADC_RDY_TIMEOUT 100
/* Maximum ADC channel number */
#define SC27XX_ADC_CHANNEL_MAX 32
/* ADC voltage ratio definition */
#define SC27XX_VOLT_RATIO(n, d) \
(((n) << SC27XX_RATIO_NUMERATOR_OFFSET) | (d))
#define SC27XX_RATIO_NUMERATOR_OFFSET 16
#define SC27XX_RATIO_DENOMINATOR_MASK GENMASK(15, 0)
struct sc27xx_adc_data {
struct device *dev;
struct regmap *regmap;
/*
* One hardware spinlock to synchronize between the multiple
* subsystems which will access the unique ADC controller.
*/
struct hwspinlock *hwlock;
struct completion completion;
int channel_scale[SC27XX_ADC_CHANNEL_MAX];
u32 base;
int value;
int irq;
};
struct sc27xx_adc_linear_graph {
int volt0;
int adc0;
int volt1;
int adc1;
};
/*
* According to the datasheet, we can convert one ADC value to one voltage value
* through 2 points in the linear graph. If the voltage is less than 1.2v, we
* should use the small-scale graph, and if more than 1.2v, we should use the
* big-scale graph.
*/
static struct sc27xx_adc_linear_graph big_scale_graph = {
4200, 3310,
3600, 2832,
};
static struct sc27xx_adc_linear_graph small_scale_graph = {
1000, 3413,
100, 341,
};
static const struct sc27xx_adc_linear_graph big_scale_graph_calib = {
4200, 856,
3600, 733,
};
static const struct sc27xx_adc_linear_graph small_scale_graph_calib = {
1000, 833,
100, 80,
};
static int sc27xx_adc_get_calib_data(u32 calib_data, int calib_adc)
{
return ((calib_data & 0xff) + calib_adc - 128) * 4;
}
static int sc27xx_adc_scale_calibration(struct sc27xx_adc_data *data,
bool big_scale)
{
const struct sc27xx_adc_linear_graph *calib_graph;
struct sc27xx_adc_linear_graph *graph;
struct nvmem_cell *cell;
const char *cell_name;
u32 calib_data = 0;
void *buf;
size_t len;
if (big_scale) {
calib_graph = &big_scale_graph_calib;
graph = &big_scale_graph;
cell_name = "big_scale_calib";
} else {
calib_graph = &small_scale_graph_calib;
graph = &small_scale_graph;
cell_name = "small_scale_calib";
}
cell = nvmem_cell_get(data->dev, cell_name);
if (IS_ERR(cell))
return PTR_ERR(cell);
buf = nvmem_cell_read(cell, &len);
nvmem_cell_put(cell);
if (IS_ERR(buf))
return PTR_ERR(buf);
memcpy(&calib_data, buf, min(len, sizeof(u32)));
/* Only need to calibrate the adc values in the linear graph. */
graph->adc0 = sc27xx_adc_get_calib_data(calib_data, calib_graph->adc0);
graph->adc1 = sc27xx_adc_get_calib_data(calib_data >> 8,
calib_graph->adc1);
kfree(buf);
return 0;
}
static int sc27xx_adc_get_ratio(int channel, int scale)
{
switch (channel) {
case 1:
case 2:
case 3:
case 4:
return scale ? SC27XX_VOLT_RATIO(400, 1025) :
SC27XX_VOLT_RATIO(1, 1);
case 5:
return SC27XX_VOLT_RATIO(7, 29);
case 6:
return SC27XX_VOLT_RATIO(375, 9000);
case 7:
case 8:
return scale ? SC27XX_VOLT_RATIO(100, 125) :
SC27XX_VOLT_RATIO(1, 1);
case 19:
return SC27XX_VOLT_RATIO(1, 3);
default:
return SC27XX_VOLT_RATIO(1, 1);
}
return SC27XX_VOLT_RATIO(1, 1);
}
static int sc27xx_adc_read(struct sc27xx_adc_data *data, int channel,
int scale, int *val)
{
int ret;
u32 tmp;
reinit_completion(&data->completion);
ret = hwspin_lock_timeout_raw(data->hwlock, SC27XX_ADC_HWLOCK_TIMEOUT);
if (ret) {
dev_err(data->dev, "timeout to get the hwspinlock\n");
return ret;
}
ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL,
SC27XX_ADC_EN, SC27XX_ADC_EN);
if (ret)
goto unlock_adc;
/* Configure the channel id and scale */
tmp = (scale << SC27XX_ADC_SCALE_SHIFT) & SC27XX_ADC_SCALE_MASK;
tmp |= channel & SC27XX_ADC_CHN_ID_MASK;
ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CH_CFG,
SC27XX_ADC_CHN_ID_MASK | SC27XX_ADC_SCALE_MASK,
tmp);
if (ret)
goto disable_adc;
/* Select 12bit conversion mode, and only sample 1 time */
tmp = SC27XX_ADC_12BIT_MODE;
tmp |= (0 << SC27XX_ADC_RUN_NUM_SHIFT) & SC27XX_ADC_RUN_NUM_MASK;
ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL,
SC27XX_ADC_RUN_NUM_MASK | SC27XX_ADC_12BIT_MODE,
tmp);
if (ret)
goto disable_adc;
ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL,
SC27XX_ADC_CHN_RUN, SC27XX_ADC_CHN_RUN);
if (ret)
goto disable_adc;
ret = wait_for_completion_timeout(&data->completion,
msecs_to_jiffies(SC27XX_ADC_RDY_TIMEOUT));
if (!ret) {
dev_err(data->dev, "read ADC data timeout\n");
ret = -ETIMEDOUT;
} else {
ret = 0;
}
disable_adc:
regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL,
SC27XX_ADC_EN, 0);
unlock_adc:
hwspin_unlock_raw(data->hwlock);
if (!ret)
*val = data->value;
return ret;
}
static irqreturn_t sc27xx_adc_isr(int irq, void *dev_id)
{
struct sc27xx_adc_data *data = dev_id;
int ret;
ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_INT_CLR,
SC27XX_ADC_IRQ_CLR, SC27XX_ADC_IRQ_CLR);
if (ret)
return IRQ_RETVAL(ret);
ret = regmap_read(data->regmap, data->base + SC27XX_ADC_DATA,
&data->value);
if (ret)
return IRQ_RETVAL(ret);
data->value &= SC27XX_ADC_DATA_MASK;
complete(&data->completion);
return IRQ_HANDLED;
}
static void sc27xx_adc_volt_ratio(struct sc27xx_adc_data *data,
int channel, int scale,
u32 *div_numerator, u32 *div_denominator)
{
u32 ratio = sc27xx_adc_get_ratio(channel, scale);
*div_numerator = ratio >> SC27XX_RATIO_NUMERATOR_OFFSET;
*div_denominator = ratio & SC27XX_RATIO_DENOMINATOR_MASK;
}
static int sc27xx_adc_to_volt(struct sc27xx_adc_linear_graph *graph,
int raw_adc)
{
int tmp;
tmp = (graph->volt0 - graph->volt1) * (raw_adc - graph->adc1);
tmp /= (graph->adc0 - graph->adc1);
tmp += graph->volt1;
return tmp < 0 ? 0 : tmp;
}
static int sc27xx_adc_convert_volt(struct sc27xx_adc_data *data, int channel,
int scale, int raw_adc)
{
u32 numerator, denominator;
u32 volt;
/*
* Convert ADC values to voltage values according to the linear graph,
* and channel 5 and channel 1 has been calibrated, so we can just
* return the voltage values calculated by the linear graph. But other
* channels need be calculated to the real voltage values with the
* voltage ratio.
*/
switch (channel) {
case 5:
return sc27xx_adc_to_volt(&big_scale_graph, raw_adc);
case 1:
return sc27xx_adc_to_volt(&small_scale_graph, raw_adc);
default:
volt = sc27xx_adc_to_volt(&small_scale_graph, raw_adc);
break;
}
sc27xx_adc_volt_ratio(data, channel, scale, &numerator, &denominator);
return (volt * denominator + numerator / 2) / numerator;
}
static int sc27xx_adc_read_processed(struct sc27xx_adc_data *data,
int channel, int scale, int *val)
{
int ret, raw_adc;
ret = sc27xx_adc_read(data, channel, scale, &raw_adc);
if (ret)
return ret;
*val = sc27xx_adc_convert_volt(data, channel, scale, raw_adc);
return 0;
}
static int sc27xx_adc_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct sc27xx_adc_data *data = iio_priv(indio_dev);
int scale = data->channel_scale[chan->channel];
int ret, tmp;
switch (mask) {
case IIO_CHAN_INFO_RAW:
mutex_lock(&indio_dev->mlock);
ret = sc27xx_adc_read(data, chan->channel, scale, &tmp);
mutex_unlock(&indio_dev->mlock);
if (ret)
return ret;
*val = tmp;
return IIO_VAL_INT;
case IIO_CHAN_INFO_PROCESSED:
mutex_lock(&indio_dev->mlock);
ret = sc27xx_adc_read_processed(data, chan->channel, scale,
&tmp);
mutex_unlock(&indio_dev->mlock);
if (ret)
return ret;
*val = tmp;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = scale;
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static int sc27xx_adc_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct sc27xx_adc_data *data = iio_priv(indio_dev);
switch (mask) {
case IIO_CHAN_INFO_SCALE:
data->channel_scale[chan->channel] = val;
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static const struct iio_info sc27xx_info = {
.read_raw = &sc27xx_adc_read_raw,
.write_raw = &sc27xx_adc_write_raw,
};
#define SC27XX_ADC_CHANNEL(index, mask) { \
.type = IIO_VOLTAGE, \
.channel = index, \
.info_mask_separate = mask | BIT(IIO_CHAN_INFO_SCALE), \
.datasheet_name = "CH##index", \
.indexed = 1, \
}
static const struct iio_chan_spec sc27xx_channels[] = {
SC27XX_ADC_CHANNEL(0, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(1, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(2, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(3, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(4, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(5, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(6, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(7, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(8, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(9, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(10, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(11, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(12, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(13, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(14, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(15, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(16, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(17, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(18, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(19, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(20, BIT(IIO_CHAN_INFO_RAW)),
SC27XX_ADC_CHANNEL(21, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(22, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(23, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(24, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(25, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(26, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(27, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(28, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(29, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(30, BIT(IIO_CHAN_INFO_PROCESSED)),
SC27XX_ADC_CHANNEL(31, BIT(IIO_CHAN_INFO_PROCESSED)),
};
static int sc27xx_adc_enable(struct sc27xx_adc_data *data)
{
int ret;
ret = regmap_update_bits(data->regmap, SC27XX_MODULE_EN,
SC27XX_MODULE_ADC_EN, SC27XX_MODULE_ADC_EN);
if (ret)
return ret;
/* Enable ADC work clock and controller clock */
ret = regmap_update_bits(data->regmap, SC27XX_ARM_CLK_EN,
SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN,
SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN);
if (ret)
goto disable_adc;
ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_INT_EN,
SC27XX_ADC_IRQ_EN, SC27XX_ADC_IRQ_EN);
if (ret)
goto disable_clk;
/* ADC channel scales' calibration from nvmem device */
ret = sc27xx_adc_scale_calibration(data, true);
if (ret)
goto disable_clk;
ret = sc27xx_adc_scale_calibration(data, false);
if (ret)
goto disable_clk;
return 0;
disable_clk:
regmap_update_bits(data->regmap, SC27XX_ARM_CLK_EN,
SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN, 0);
disable_adc:
regmap_update_bits(data->regmap, SC27XX_MODULE_EN,
SC27XX_MODULE_ADC_EN, 0);
return ret;
}
static void sc27xx_adc_disable(void *_data)
{
struct sc27xx_adc_data *data = _data;
regmap_update_bits(data->regmap, data->base + SC27XX_ADC_INT_EN,
SC27XX_ADC_IRQ_EN, 0);
/* Disable ADC work clock and controller clock */
regmap_update_bits(data->regmap, SC27XX_ARM_CLK_EN,
SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN, 0);
regmap_update_bits(data->regmap, SC27XX_MODULE_EN,
SC27XX_MODULE_ADC_EN, 0);
}
static void sc27xx_adc_free_hwlock(void *_data)
{
struct hwspinlock *hwlock = _data;
hwspin_lock_free(hwlock);
}
static int sc27xx_adc_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct sc27xx_adc_data *sc27xx_data;
struct iio_dev *indio_dev;
int ret;
indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*sc27xx_data));
if (!indio_dev)
return -ENOMEM;
sc27xx_data = iio_priv(indio_dev);
sc27xx_data->regmap = dev_get_regmap(pdev->dev.parent, NULL);
if (!sc27xx_data->regmap) {
dev_err(&pdev->dev, "failed to get ADC regmap\n");
return -ENODEV;
}
ret = of_property_read_u32(np, "reg", &sc27xx_data->base);
if (ret) {
dev_err(&pdev->dev, "failed to get ADC base address\n");
return ret;
}
sc27xx_data->irq = platform_get_irq(pdev, 0);
if (sc27xx_data->irq < 0) {
dev_err(&pdev->dev, "failed to get ADC irq number\n");
return sc27xx_data->irq;
}
ret = of_hwspin_lock_get_id(np, 0);
if (ret < 0) {
dev_err(&pdev->dev, "failed to get hwspinlock id\n");
return ret;
}
sc27xx_data->hwlock = hwspin_lock_request_specific(ret);
if (!sc27xx_data->hwlock) {
dev_err(&pdev->dev, "failed to request hwspinlock\n");
return -ENXIO;
}
ret = devm_add_action(&pdev->dev, sc27xx_adc_free_hwlock,
sc27xx_data->hwlock);
if (ret) {
sc27xx_adc_free_hwlock(sc27xx_data->hwlock);
dev_err(&pdev->dev, "failed to add hwspinlock action\n");
return ret;
}
init_completion(&sc27xx_data->completion);
sc27xx_data->dev = &pdev->dev;
ret = sc27xx_adc_enable(sc27xx_data);
if (ret) {
dev_err(&pdev->dev, "failed to enable ADC module\n");
return ret;
}
ret = devm_add_action(&pdev->dev, sc27xx_adc_disable, sc27xx_data);
if (ret) {
sc27xx_adc_disable(sc27xx_data);
dev_err(&pdev->dev, "failed to add ADC disable action\n");
return ret;
}
ret = devm_request_threaded_irq(&pdev->dev, sc27xx_data->irq, NULL,
sc27xx_adc_isr, IRQF_ONESHOT,
pdev->name, sc27xx_data);
if (ret) {
dev_err(&pdev->dev, "failed to request ADC irq\n");
return ret;
}
indio_dev->dev.parent = &pdev->dev;
indio_dev->name = dev_name(&pdev->dev);
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->info = &sc27xx_info;
indio_dev->channels = sc27xx_channels;
indio_dev->num_channels = ARRAY_SIZE(sc27xx_channels);
ret = devm_iio_device_register(&pdev->dev, indio_dev);
if (ret)
dev_err(&pdev->dev, "could not register iio (ADC)");
return ret;
}
static const struct of_device_id sc27xx_adc_of_match[] = {
{ .compatible = "sprd,sc2731-adc", },
{ }
};
static struct platform_driver sc27xx_adc_driver = {
.probe = sc27xx_adc_probe,
.driver = {
.name = "sc27xx-adc",
.of_match_table = sc27xx_adc_of_match,
},
};
module_platform_driver(sc27xx_adc_driver);
MODULE_AUTHOR("Freeman Liu <freeman.liu@spreadtrum.com>");
MODULE_DESCRIPTION("Spreadtrum SC27XX ADC Driver");
MODULE_LICENSE("GPL v2");
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