[v5,2/2] iio: adc: rn5t618: Add ADC driver for RN5T618/RC5T619
diff mbox series

Message ID 20200223131638.12130-3-andreas@kemnade.info
State New
Headers show
Series
  • mfd: rn5t618: add ADC support
Related show

Commit Message

Andreas Kemnade Feb. 23, 2020, 1:16 p.m. UTC
Both chips have an A/D converter capable of measuring
things like VBAT, VUSB and analog inputs.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
depends on (build and runtime):
https://lore.kernel.org/lkml/20191220122416.31881-1-andreas@kemnade.info/

Changes in v4:
- merged ret = and return into one line
- added Reviewed-by:

Changes in v3:
- output scale instead of processed
- prefixed symbols with RN5T618

Changes in v2:
- enum for channels
- bulk read instead of single byte read for conversion
  result
- fix get_virq error handling
- use devm for registering device and requesting IRQ

 drivers/iio/adc/Kconfig       |  10 ++
 drivers/iio/adc/Makefile      |   1 +
 drivers/iio/adc/rn5t618-adc.c | 256 ++++++++++++++++++++++++++++++++++
 3 files changed, 267 insertions(+)
 create mode 100644 drivers/iio/adc/rn5t618-adc.c

Comments

Andreas Kemnade Feb. 26, 2020, 7:27 p.m. UTC | #1
Hi,

On Sun, 23 Feb 2020 14:16:38 +0100
Andreas Kemnade <andreas@kemnade.info> wrote:


> +	if (rn5t618->irq_data)
> +		adc->irq = regmap_irq_get_virq(rn5t618->irq_data,
> +					       RN5T618_IRQ_ADC);
> +
RN5T618_IRQ_ADC is defined in the RTC patchset mentioned as dependency,
which adds IRQ support and I am asked to rebase it on top of plain mainline.
Does that mean that the kernel git source does not need to be bisectable
anymore?


Regards,
Andreas

Patch
diff mbox series

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 5d8540b7b427..e7e74e775336 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -766,6 +766,16 @@  config RCAR_GYRO_ADC
 	  To compile this driver as a module, choose M here: the
 	  module will be called rcar-gyroadc.
 
+config RN5T618_ADC
+	tristate "ADC for the RN5T618/RC5T619 family of chips"
+	depends on MFD_RN5T618
+	help
+	  Say yes here to build support for the integrated ADC inside the
+	  RN5T618/619 series PMICs:
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rn5t618-adc.
+
 config ROCKCHIP_SARADC
 	tristate "Rockchip SARADC driver"
 	depends on ARCH_ROCKCHIP || (ARM && COMPILE_TEST)
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index a1f1fbec0f87..ea95f89c91cd 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -72,6 +72,7 @@  obj-$(CONFIG_QCOM_VADC_COMMON) += qcom-vadc-common.o
 obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o
 obj-$(CONFIG_QCOM_PM8XXX_XOADC) += qcom-pm8xxx-xoadc.o
 obj-$(CONFIG_RCAR_GYRO_ADC) += rcar-gyroadc.o
+obj-$(CONFIG_RN5T618_ADC) += rn5t618-adc.o
 obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
 obj-$(CONFIG_SC27XX_ADC) += sc27xx_adc.o
 obj-$(CONFIG_SPEAR_ADC) += spear_adc.o
diff --git a/drivers/iio/adc/rn5t618-adc.c b/drivers/iio/adc/rn5t618-adc.c
new file mode 100644
index 000000000000..f21027e4e26a
--- /dev/null
+++ b/drivers/iio/adc/rn5t618-adc.c
@@ -0,0 +1,256 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * ADC driver for the RICOH RN5T618 power management chip family
+ *
+ * Copyright (C) 2019 Andreas Kemnade
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mfd/rn5t618.h>
+#include <linux/platform_device.h>
+#include <linux/completion.h>
+#include <linux/regmap.h>
+#include <linux/iio/iio.h>
+#include <linux/slab.h>
+
+#define RN5T618_ADC_CONVERSION_TIMEOUT   (msecs_to_jiffies(500))
+#define RN5T618_REFERENCE_VOLT 2500
+
+/* mask for selecting channels for single conversion */
+#define RN5T618_ADCCNT3_CHANNEL_MASK 0x7
+/* average 4-time conversion mode */
+#define RN5T618_ADCCNT3_AVG BIT(3)
+/* set for starting a single conversion, gets cleared by hw when done */
+#define RN5T618_ADCCNT3_GODONE BIT(4)
+/* automatic conversion, period is in ADCCNT2, selected channels are
+ * in ADCCNT1
+ */
+#define RN5T618_ADCCNT3_AUTO BIT(5)
+#define RN5T618_ADCEND_IRQ BIT(0)
+
+struct rn5t618_adc_data {
+	struct device *dev;
+	struct rn5t618 *rn5t618;
+	struct completion conv_completion;
+	int irq;
+};
+
+struct rn5t618_channel_ratios {
+	u16 numerator;
+	u16 denominator;
+};
+
+enum rn5t618_channels {
+	LIMMON = 0,
+	VBAT,
+	VADP,
+	VUSB,
+	VSYS,
+	VTHM,
+	AIN1,
+	AIN0
+};
+
+static const struct rn5t618_channel_ratios rn5t618_ratios[8] = {
+	[LIMMON] = {50, 32}, /* measured across 20mOhm, amplified by 32 */
+	[VBAT] = {2, 1},
+	[VADP] = {3, 1},
+	[VUSB] = {3, 1},
+	[VSYS] = {3, 1},
+	[VTHM] = {1, 1},
+	[AIN1] = {1, 1},
+	[AIN0] = {1, 1},
+};
+
+static int rn5t618_read_adc_reg(struct rn5t618 *rn5t618, int reg, u16 *val)
+{
+	u8 data[2];
+	int ret;
+
+	ret = regmap_bulk_read(rn5t618->regmap, reg, data, sizeof(data));
+	if (ret < 0)
+		return ret;
+
+	*val = (data[0] << 4) | (data[1] & 0xF);
+
+	return 0;
+}
+
+static irqreturn_t rn5t618_adc_irq(int irq, void *data)
+{
+	struct rn5t618_adc_data *adc = data;
+	unsigned int r = 0;
+	int ret;
+
+	/* clear low & high threshold irqs */
+	regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC1, 0);
+	regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC2, 0);
+
+	ret = regmap_read(adc->rn5t618->regmap, RN5T618_IR_ADC3, &r);
+	if (ret < 0)
+		dev_err(adc->dev, "failed to read IRQ status: %d\n", ret);
+
+	regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC3, 0);
+
+	if (r & RN5T618_ADCEND_IRQ)
+		complete(&adc->conv_completion);
+
+	return IRQ_HANDLED;
+}
+
+static int rn5t618_adc_read(struct iio_dev *iio_dev,
+			    const struct iio_chan_spec *chan,
+			    int *val, int *val2, long mask)
+{
+	struct rn5t618_adc_data *adc = iio_priv(iio_dev);
+	u16 raw;
+	int ret;
+
+	if (mask == IIO_CHAN_INFO_SCALE) {
+		*val = RN5T618_REFERENCE_VOLT *
+		       rn5t618_ratios[chan->channel].numerator;
+		*val2 = rn5t618_ratios[chan->channel].denominator * 4095;
+
+		return IIO_VAL_FRACTIONAL;
+	}
+
+	/* select channel */
+	ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3,
+				 RN5T618_ADCCNT3_CHANNEL_MASK,
+				 chan->channel);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_write(adc->rn5t618->regmap, RN5T618_EN_ADCIR3,
+			   RN5T618_ADCEND_IRQ);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3,
+				 RN5T618_ADCCNT3_AVG,
+				 mask == IIO_CHAN_INFO_AVERAGE_RAW ?
+				 RN5T618_ADCCNT3_AVG : 0);
+	if (ret < 0)
+		return ret;
+
+	init_completion(&adc->conv_completion);
+	/* single conversion */
+	ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3,
+				 RN5T618_ADCCNT3_GODONE,
+				 RN5T618_ADCCNT3_GODONE);
+	if (ret < 0)
+		return ret;
+
+	ret = wait_for_completion_timeout(&adc->conv_completion,
+					  RN5T618_ADC_CONVERSION_TIMEOUT);
+	if (ret == 0) {
+		dev_warn(adc->dev, "timeout waiting for adc result\n");
+		return -ETIMEDOUT;
+	}
+
+	ret = rn5t618_read_adc_reg(adc->rn5t618,
+				   RN5T618_ILIMDATAH + 2 * chan->channel,
+				   &raw);
+	if (ret < 0)
+		return ret;
+
+	*val = raw;
+
+	return IIO_VAL_INT;
+}
+
+static const struct iio_info rn5t618_adc_iio_info = {
+	.read_raw = &rn5t618_adc_read,
+};
+
+#define RN5T618_ADC_CHANNEL(_channel, _type, _name) { \
+	.type = _type, \
+	.channel = _channel, \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+			      BIT(IIO_CHAN_INFO_AVERAGE_RAW) | \
+			      BIT(IIO_CHAN_INFO_SCALE), \
+	.datasheet_name = _name, \
+	.indexed = 1. \
+}
+
+static const struct iio_chan_spec rn5t618_adc_iio_channels[] = {
+	RN5T618_ADC_CHANNEL(LIMMON, IIO_CURRENT, "LIMMON"),
+	RN5T618_ADC_CHANNEL(VBAT, IIO_VOLTAGE, "VBAT"),
+	RN5T618_ADC_CHANNEL(VADP, IIO_VOLTAGE, "VADP"),
+	RN5T618_ADC_CHANNEL(VUSB, IIO_VOLTAGE, "VUSB"),
+	RN5T618_ADC_CHANNEL(VSYS, IIO_VOLTAGE, "VSYS"),
+	RN5T618_ADC_CHANNEL(VTHM, IIO_VOLTAGE, "VTHM"),
+	RN5T618_ADC_CHANNEL(AIN1, IIO_VOLTAGE, "AIN1"),
+	RN5T618_ADC_CHANNEL(AIN0, IIO_VOLTAGE, "AIN0")
+};
+
+static int rn5t618_adc_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct iio_dev *iio_dev;
+	struct rn5t618_adc_data *adc;
+	struct rn5t618 *rn5t618 = dev_get_drvdata(pdev->dev.parent);
+
+	iio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));
+	if (!iio_dev) {
+		dev_err(&pdev->dev, "failed allocating iio device\n");
+		return -ENOMEM;
+	}
+
+	adc = iio_priv(iio_dev);
+	adc->dev = &pdev->dev;
+	adc->rn5t618 = rn5t618;
+
+	if (rn5t618->irq_data)
+		adc->irq = regmap_irq_get_virq(rn5t618->irq_data,
+					       RN5T618_IRQ_ADC);
+
+	if (adc->irq <= 0) {
+		dev_err(&pdev->dev, "get virq failed\n");
+		return -EINVAL;
+	}
+
+	init_completion(&adc->conv_completion);
+
+	iio_dev->name = dev_name(&pdev->dev);
+	iio_dev->dev.parent = &pdev->dev;
+	iio_dev->info = &rn5t618_adc_iio_info;
+	iio_dev->modes = INDIO_DIRECT_MODE;
+	iio_dev->channels = rn5t618_adc_iio_channels;
+	iio_dev->num_channels = ARRAY_SIZE(rn5t618_adc_iio_channels);
+
+	/* stop any auto-conversion */
+	ret = regmap_write(rn5t618->regmap, RN5T618_ADCCNT3, 0);
+	if (ret < 0)
+		return ret;
+
+	platform_set_drvdata(pdev, iio_dev);
+
+	ret = devm_request_threaded_irq(adc->dev, adc->irq, NULL,
+					rn5t618_adc_irq,
+					IRQF_ONESHOT, dev_name(adc->dev),
+					adc);
+	if (ret < 0) {
+		dev_err(adc->dev, "request irq %d failed: %d\n", adc->irq, ret);
+		return ret;
+	}
+
+	return devm_iio_device_register(adc->dev, iio_dev);
+}
+
+static struct platform_driver rn5t618_adc_driver = {
+	.driver = {
+		.name   = "rn5t618-adc",
+	},
+	.probe = rn5t618_adc_probe,
+};
+
+module_platform_driver(rn5t618_adc_driver);
+MODULE_ALIAS("platform:rn5t618-adc");
+MODULE_DESCRIPTION("RICOH RN5T618 ADC driver");
+MODULE_LICENSE("GPL");