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IIO: add Ingenic JZ47xx ADC driver.

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Add an IIO driver for the ADC hardware present on Ingenic JZ47xx SoCs.

Signed-off-by: Artur Rojek <contact@artur-rojek.eu>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Artur Rojek 2019-02-04 01:15:14 +01:00 committed by Jonathan Cameron
parent 7cf74d515b
commit 1a78daea10
3 changed files with 374 additions and 0 deletions
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9
drivers/iio/adc/Kconfig
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@ -407,6 +407,15 @@ config INA2XX_ADC
Say yes here to build support for TI INA2xx family of Power Monitors.
This driver is mutually exclusive with the HWMON version.
config INGENIC_ADC
tristate "Ingenic JZ47xx SoCs ADC driver"
depends on MIPS || COMPILE_TEST
help
Say yes here to build support for the Ingenic JZ47xx SoCs ADC unit.
This driver can also be built as a module. If so, the module will be
called ingenic_adc.
config IMX7D_ADC
tristate "Freescale IMX7D ADC driver"
depends on ARCH_MXC || COMPILE_TEST

1
drivers/iio/adc/Makefile
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@ -40,6 +40,7 @@ obj-$(CONFIG_HI8435) += hi8435.o
obj-$(CONFIG_HX711) += hx711.o
obj-$(CONFIG_IMX7D_ADC) += imx7d_adc.o
obj-$(CONFIG_INA2XX_ADC) += ina2xx-adc.o
obj-$(CONFIG_INGENIC_ADC) += ingenic-adc.o
obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o
obj-$(CONFIG_LPC32XX_ADC) += lpc32xx_adc.o

364
drivers/iio/adc/ingenic-adc.c Normal file
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@ -0,0 +1,364 @@
// SPDX-License-Identifier: GPL-2.0
/*
* ADC driver for the Ingenic JZ47xx SoCs
* Copyright (c) 2019 Artur Rojek <contact@artur-rojek.eu>
*
* based on drivers/mfd/jz4740-adc.c
*/
#include <dt-bindings/iio/adc/ingenic,adc.h>
#include <linux/clk.h>
#include <linux/iio/iio.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#define JZ_ADC_REG_ENABLE 0x00
#define JZ_ADC_REG_CFG 0x04
#define JZ_ADC_REG_CTRL 0x08
#define JZ_ADC_REG_STATUS 0x0c
#define JZ_ADC_REG_ADTCH 0x18
#define JZ_ADC_REG_ADBDAT 0x1c
#define JZ_ADC_REG_ADSDAT 0x20
#define JZ_ADC_REG_CFG_BAT_MD BIT(4)
#define JZ_ADC_AUX_VREF 3300
#define JZ_ADC_AUX_VREF_BITS 12
#define JZ_ADC_BATTERY_LOW_VREF 2500
#define JZ_ADC_BATTERY_LOW_VREF_BITS 12
#define JZ4725B_ADC_BATTERY_HIGH_VREF 7500
#define JZ4725B_ADC_BATTERY_HIGH_VREF_BITS 10
#define JZ4740_ADC_BATTERY_HIGH_VREF (7500 * 0.986)
#define JZ4740_ADC_BATTERY_HIGH_VREF_BITS 12
struct ingenic_adc_soc_data {
unsigned int battery_high_vref;
unsigned int battery_high_vref_bits;
const int *battery_raw_avail;
size_t battery_raw_avail_size;
const int *battery_scale_avail;
size_t battery_scale_avail_size;
};
struct ingenic_adc {
void __iomem *base;
struct clk *clk;
struct mutex lock;
const struct ingenic_adc_soc_data *soc_data;
bool low_vref_mode;
};
static void ingenic_adc_set_config(struct ingenic_adc *adc,
uint32_t mask,
uint32_t val)
{
uint32_t cfg;
clk_enable(adc->clk);
mutex_lock(&adc->lock);
cfg = readl(adc->base + JZ_ADC_REG_CFG) & ~mask;
cfg |= val;
writel(cfg, adc->base + JZ_ADC_REG_CFG);
mutex_unlock(&adc->lock);
clk_disable(adc->clk);
}
static void ingenic_adc_enable(struct ingenic_adc *adc,
int engine,
bool enabled)
{
u8 val;
mutex_lock(&adc->lock);
val = readb(adc->base + JZ_ADC_REG_ENABLE);
if (enabled)
val |= BIT(engine);
else
val &= ~BIT(engine);
writeb(val, adc->base + JZ_ADC_REG_ENABLE);
mutex_unlock(&adc->lock);
}
static int ingenic_adc_capture(struct ingenic_adc *adc,
int engine)
{
u8 val;
int ret;
ingenic_adc_enable(adc, engine, true);
ret = readb_poll_timeout(adc->base + JZ_ADC_REG_ENABLE, val,
!(val & BIT(engine)), 250, 1000);
if (ret)
ingenic_adc_enable(adc, engine, false);
return ret;
}
static int ingenic_adc_write_raw(struct iio_dev *iio_dev,
struct iio_chan_spec const *chan,
int val,
int val2,
long m)
{
struct ingenic_adc *adc = iio_priv(iio_dev);
switch (m) {
case IIO_CHAN_INFO_SCALE:
switch (chan->channel) {
case INGENIC_ADC_BATTERY:
if (val > JZ_ADC_BATTERY_LOW_VREF) {
ingenic_adc_set_config(adc,
JZ_ADC_REG_CFG_BAT_MD,
0);
adc->low_vref_mode = false;
} else {
ingenic_adc_set_config(adc,
JZ_ADC_REG_CFG_BAT_MD,
JZ_ADC_REG_CFG_BAT_MD);
adc->low_vref_mode = true;
}
return 0;
default:
return -EINVAL;
}
default:
return -EINVAL;
}
}
static const int jz4725b_adc_battery_raw_avail[] = {
0, 1, (1 << JZ_ADC_BATTERY_LOW_VREF_BITS) - 1,
};
static const int jz4725b_adc_battery_scale_avail[] = {
JZ4725B_ADC_BATTERY_HIGH_VREF, JZ4725B_ADC_BATTERY_HIGH_VREF_BITS,
JZ_ADC_BATTERY_LOW_VREF, JZ_ADC_BATTERY_LOW_VREF_BITS,
};
static const int jz4740_adc_battery_raw_avail[] = {
0, 1, (1 << JZ_ADC_BATTERY_LOW_VREF_BITS) - 1,
};
static const int jz4740_adc_battery_scale_avail[] = {
JZ4740_ADC_BATTERY_HIGH_VREF, JZ4740_ADC_BATTERY_HIGH_VREF_BITS,
JZ_ADC_BATTERY_LOW_VREF, JZ_ADC_BATTERY_LOW_VREF_BITS,
};
static const struct ingenic_adc_soc_data jz4725b_adc_soc_data = {
.battery_high_vref = JZ4725B_ADC_BATTERY_HIGH_VREF,
.battery_high_vref_bits = JZ4725B_ADC_BATTERY_HIGH_VREF_BITS,
.battery_raw_avail = jz4725b_adc_battery_raw_avail,
.battery_raw_avail_size = ARRAY_SIZE(jz4725b_adc_battery_raw_avail),
.battery_scale_avail = jz4725b_adc_battery_scale_avail,
.battery_scale_avail_size = ARRAY_SIZE(jz4725b_adc_battery_scale_avail),
};
static const struct ingenic_adc_soc_data jz4740_adc_soc_data = {
.battery_high_vref = JZ4740_ADC_BATTERY_HIGH_VREF,
.battery_high_vref_bits = JZ4740_ADC_BATTERY_HIGH_VREF_BITS,
.battery_raw_avail = jz4740_adc_battery_raw_avail,
.battery_raw_avail_size = ARRAY_SIZE(jz4740_adc_battery_raw_avail),
.battery_scale_avail = jz4740_adc_battery_scale_avail,
.battery_scale_avail_size = ARRAY_SIZE(jz4740_adc_battery_scale_avail),
};
static int ingenic_adc_read_avail(struct iio_dev *iio_dev,
struct iio_chan_spec const *chan,
const int **vals,
int *type,
int *length,
long m)
{
struct ingenic_adc *adc = iio_priv(iio_dev);
switch (m) {
case IIO_CHAN_INFO_RAW:
*type = IIO_VAL_INT;
*length = adc->soc_data->battery_raw_avail_size;
*vals = adc->soc_data->battery_raw_avail;
return IIO_AVAIL_RANGE;
case IIO_CHAN_INFO_SCALE:
*type = IIO_VAL_FRACTIONAL_LOG2;
*length = adc->soc_data->battery_scale_avail_size;
*vals = adc->soc_data->battery_scale_avail;
return IIO_AVAIL_LIST;
default:
return -EINVAL;
};
}
static int ingenic_adc_read_raw(struct iio_dev *iio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
struct ingenic_adc *adc = iio_priv(iio_dev);
int ret;
switch (m) {
case IIO_CHAN_INFO_RAW:
clk_enable(adc->clk);
ret = ingenic_adc_capture(adc, chan->channel);
if (ret) {
clk_disable(adc->clk);
return ret;
}
switch (chan->channel) {
case INGENIC_ADC_AUX:
*val = readw(adc->base + JZ_ADC_REG_ADSDAT);
break;
case INGENIC_ADC_BATTERY:
*val = readw(adc->base + JZ_ADC_REG_ADBDAT);
break;
}
clk_disable(adc->clk);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
switch (chan->channel) {
case INGENIC_ADC_AUX:
*val = JZ_ADC_AUX_VREF;
*val2 = JZ_ADC_AUX_VREF_BITS;
break;
case INGENIC_ADC_BATTERY:
if (adc->low_vref_mode) {
*val = JZ_ADC_BATTERY_LOW_VREF;
*val2 = JZ_ADC_BATTERY_LOW_VREF_BITS;
} else {
*val = adc->soc_data->battery_high_vref;
*val2 = adc->soc_data->battery_high_vref_bits;
}
break;
}
return IIO_VAL_FRACTIONAL_LOG2;
default:
return -EINVAL;
}
}
static void ingenic_adc_clk_cleanup(void *data)
{
clk_unprepare(data);
}
static const struct iio_info ingenic_adc_info = {
.write_raw = ingenic_adc_write_raw,
.read_raw = ingenic_adc_read_raw,
.read_avail = ingenic_adc_read_avail,
};
static const struct iio_chan_spec ingenic_channels[] = {
{
.extend_name = "aux",
.type = IIO_VOLTAGE,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE),
.indexed = 1,
.channel = INGENIC_ADC_AUX,
},
{
.extend_name = "battery",
.type = IIO_VOLTAGE,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE),
.info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE),
.indexed = 1,
.channel = INGENIC_ADC_BATTERY,
},
};
static int ingenic_adc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct iio_dev *iio_dev;
struct ingenic_adc *adc;
struct resource *mem_base;
const struct ingenic_adc_soc_data *soc_data;
int ret;
soc_data = device_get_match_data(dev);
if (!soc_data)
return -EINVAL;
iio_dev = devm_iio_device_alloc(dev, sizeof(*adc));
if (!iio_dev)
return -ENOMEM;
adc = iio_priv(iio_dev);
mutex_init(&adc->lock);
adc->soc_data = soc_data;
mem_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
adc->base = devm_ioremap_resource(dev, mem_base);
if (IS_ERR(adc->base)) {
dev_err(dev, "Unable to ioremap mmio resource\n");
return PTR_ERR(adc->base);
}
adc->clk = devm_clk_get(dev, "adc");
if (IS_ERR(adc->clk)) {
dev_err(dev, "Unable to get clock\n");
return PTR_ERR(adc->clk);
}
ret = clk_prepare_enable(adc->clk);
if (ret) {
dev_err(dev, "Failed to enable clock\n");
return ret;
}
/* Put hardware in a known passive state. */
writeb(0x00, adc->base + JZ_ADC_REG_ENABLE);
writeb(0xff, adc->base + JZ_ADC_REG_CTRL);
clk_disable(adc->clk);
ret = devm_add_action_or_reset(dev, ingenic_adc_clk_cleanup, adc->clk);
if (ret) {
dev_err(dev, "Unable to add action\n");
return ret;
}
iio_dev->dev.parent = dev;
iio_dev->name = "jz-adc";
iio_dev->modes = INDIO_DIRECT_MODE;
iio_dev->channels = ingenic_channels;
iio_dev->num_channels = ARRAY_SIZE(ingenic_channels);
iio_dev->info = &ingenic_adc_info;
ret = devm_iio_device_register(dev, iio_dev);
if (ret)
dev_err(dev, "Unable to register IIO device\n");
return ret;
}
#ifdef CONFIG_OF
static const struct of_device_id ingenic_adc_of_match[] = {
{ .compatible = "ingenic,jz4725b-adc", .data = &jz4725b_adc_soc_data, },
{ .compatible = "ingenic,jz4740-adc", .data = &jz4740_adc_soc_data, },
{ },
};
MODULE_DEVICE_TABLE(of, ingenic_adc_of_match);
#endif
static struct platform_driver ingenic_adc_driver = {
.driver = {
.name = "ingenic-adc",
.of_match_table = of_match_ptr(ingenic_adc_of_match),
},
.probe = ingenic_adc_probe,
};
module_platform_driver(ingenic_adc_driver);
MODULE_LICENSE("GPL v2");