iio: Add support for DA9150 GPADC

This patch adds support for DA9150 Charger & Fuel-Gauge IC GPADC.
Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Reviewed-by: Hartmut Knaack <knaack.h@gmx.de>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Sebastian Reichel <sre@kernel.org>

drivers/iio/adc/Kconfig

@@ -135,6 +135,15 @@ config AXP288_ADC
 	  device. Depending on platform configuration, this general purpose ADC can
 	  be used for sampling sensors such as thermal resistors.
 
+config DA9150_GPADC
+	tristate "Dialog DA9150 GPADC driver support"
+	depends on MFD_DA9150
+	help
+	  Say yes here to build support for Dialog DA9150 GPADC.
+
+	  This driver can also be built as a module. If chosen, the module name
+	  will be da9150-gpadc.
+
 config CC10001_ADC
 	tristate "Cosmic Circuits 10001 ADC driver"
 	depends on HAS_IOMEM || HAVE_CLK || REGULATOR

drivers/iio/adc/Makefile

@@ -15,6 +15,7 @@ obj-$(CONFIG_AD7887) += ad7887.o
 obj-$(CONFIG_AD799X) += ad799x.o
 obj-$(CONFIG_AT91_ADC) += at91_adc.o
 obj-$(CONFIG_AXP288_ADC) += axp288_adc.o
+obj-$(CONFIG_DA9150_GPADC) += da9150-gpadc.o
 obj-$(CONFIG_CC10001_ADC) += cc10001_adc.o
 obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o
 obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o

drivers/iio/adc/da9150-gpadc.c

+/*
+ * DA9150 GPADC Driver
+ *
+ * Copyright (c) 2014 Dialog Semiconductor
+ *
+ * Author: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/mutex.h>
+#include <linux/completion.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/machine.h>
+#include <linux/iio/driver.h>
+#include <linux/mfd/da9150/core.h>
+#include <linux/mfd/da9150/registers.h>
+
+/* Channels */
+enum da9150_gpadc_hw_channel {
+	DA9150_GPADC_HW_CHAN_GPIOA_2V = 0,
+	DA9150_GPADC_HW_CHAN_GPIOA_2V_,
+	DA9150_GPADC_HW_CHAN_GPIOB_2V,
+	DA9150_GPADC_HW_CHAN_GPIOB_2V_,
+	DA9150_GPADC_HW_CHAN_GPIOC_2V,
+	DA9150_GPADC_HW_CHAN_GPIOC_2V_,
+	DA9150_GPADC_HW_CHAN_GPIOD_2V,
+	DA9150_GPADC_HW_CHAN_GPIOD_2V_,
+	DA9150_GPADC_HW_CHAN_IBUS_SENSE,
+	DA9150_GPADC_HW_CHAN_IBUS_SENSE_,
+	DA9150_GPADC_HW_CHAN_VBUS_DIV,
+	DA9150_GPADC_HW_CHAN_VBUS_DIV_,
+	DA9150_GPADC_HW_CHAN_ID,
+	DA9150_GPADC_HW_CHAN_ID_,
+	DA9150_GPADC_HW_CHAN_VSYS,
+	DA9150_GPADC_HW_CHAN_VSYS_,
+	DA9150_GPADC_HW_CHAN_GPIOA_6V,
+	DA9150_GPADC_HW_CHAN_GPIOA_6V_,
+	DA9150_GPADC_HW_CHAN_GPIOB_6V,
+	DA9150_GPADC_HW_CHAN_GPIOB_6V_,
+	DA9150_GPADC_HW_CHAN_GPIOC_6V,
+	DA9150_GPADC_HW_CHAN_GPIOC_6V_,
+	DA9150_GPADC_HW_CHAN_GPIOD_6V,
+	DA9150_GPADC_HW_CHAN_GPIOD_6V_,
+	DA9150_GPADC_HW_CHAN_VBAT,
+	DA9150_GPADC_HW_CHAN_VBAT_,
+	DA9150_GPADC_HW_CHAN_TBAT,
+	DA9150_GPADC_HW_CHAN_TBAT_,
+	DA9150_GPADC_HW_CHAN_TJUNC_CORE,
+	DA9150_GPADC_HW_CHAN_TJUNC_CORE_,
+	DA9150_GPADC_HW_CHAN_TJUNC_OVP,
+	DA9150_GPADC_HW_CHAN_TJUNC_OVP_,
+};
+
+enum da9150_gpadc_channel {
+	DA9150_GPADC_CHAN_GPIOA = 0,
+	DA9150_GPADC_CHAN_GPIOB,
+	DA9150_GPADC_CHAN_GPIOC,
+	DA9150_GPADC_CHAN_GPIOD,
+	DA9150_GPADC_CHAN_IBUS,
+	DA9150_GPADC_CHAN_VBUS,
+	DA9150_GPADC_CHAN_VSYS,
+	DA9150_GPADC_CHAN_VBAT,
+	DA9150_GPADC_CHAN_TBAT,
+	DA9150_GPADC_CHAN_TJUNC_CORE,
+	DA9150_GPADC_CHAN_TJUNC_OVP,
+};
+
+/* Private data */
+struct da9150_gpadc {
+	struct da9150 *da9150;
+	struct device *dev;
+
+	struct mutex lock;
+	struct completion complete;
+};
+
+
+static irqreturn_t da9150_gpadc_irq(int irq, void *data)
+{
+
+	struct da9150_gpadc *gpadc = data;
+
+	complete(&gpadc->complete);
+
+	return IRQ_HANDLED;
+}
+
+static int da9150_gpadc_read_adc(struct da9150_gpadc *gpadc, int hw_chan)
+{
+	u8 result_regs[2];
+	int result;
+
+	mutex_lock(&gpadc->lock);
+
+	/* Set channel & enable measurement */
+	da9150_reg_write(gpadc->da9150, DA9150_GPADC_MAN,
+			 (DA9150_GPADC_EN_MASK |
+			  hw_chan << DA9150_GPADC_MUX_SHIFT));
+
+	/* Consume left-over completion from a previous timeout */
+	try_wait_for_completion(&gpadc->complete);
+
+	/* Check for actual completion */
+	wait_for_completion_timeout(&gpadc->complete, msecs_to_jiffies(5));
+
+	/* Read result and status from device */
+	da9150_bulk_read(gpadc->da9150, DA9150_GPADC_RES_A, 2, result_regs);
+
+	mutex_unlock(&gpadc->lock);
+
+	/* Check to make sure device really has completed reading */
+	if (result_regs[1] & DA9150_GPADC_RUN_MASK) {
+		dev_err(gpadc->dev, "Timeout on channel %d of GPADC\n",
+			hw_chan);
+		return -ETIMEDOUT;
+	}
+
+	/* LSBs - 2 bits */
+	result = (result_regs[1] & DA9150_GPADC_RES_L_MASK) >>
+		 DA9150_GPADC_RES_L_SHIFT;
+	/* MSBs - 8 bits */
+	result |= result_regs[0] << DA9150_GPADC_RES_L_BITS;
+
+	return result;
+}
+
+static inline int da9150_gpadc_gpio_6v_voltage_now(int raw_val)
+{
+	/* Convert to mV */
+	return (6 * ((raw_val * 1000) + 500)) / 1024;
+}
+
+static inline int da9150_gpadc_ibus_current_avg(int raw_val)
+{
+	/* Convert to mA */
+	return (4 * ((raw_val * 1000) + 500)) / 2048;
+}
+
+static inline int da9150_gpadc_vbus_21v_voltage_now(int raw_val)
+{
+	/* Convert to mV */
+	return (21 * ((raw_val * 1000) + 500)) / 1024;
+}
+
+static inline int da9150_gpadc_vsys_6v_voltage_now(int raw_val)
+{
+	/* Convert to mV */
+	return (3 * ((raw_val * 1000) + 500)) / 512;
+}
+
+static int da9150_gpadc_read_processed(struct da9150_gpadc *gpadc, int channel,
+				       int hw_chan, int *val)
+{
+	int raw_val;
+
+	raw_val = da9150_gpadc_read_adc(gpadc, hw_chan);
+	if (raw_val < 0)
+		return raw_val;
+
+	switch (channel) {
+	case DA9150_GPADC_CHAN_GPIOA:
+	case DA9150_GPADC_CHAN_GPIOB:
+	case DA9150_GPADC_CHAN_GPIOC:
+	case DA9150_GPADC_CHAN_GPIOD:
+		*val = da9150_gpadc_gpio_6v_voltage_now(raw_val);
+		break;
+	case DA9150_GPADC_CHAN_IBUS:
+		*val = da9150_gpadc_ibus_current_avg(raw_val);
+		break;
+	case DA9150_GPADC_CHAN_VBUS:
+		*val = da9150_gpadc_vbus_21v_voltage_now(raw_val);
+		break;
+	case DA9150_GPADC_CHAN_VSYS:
+		*val = da9150_gpadc_vsys_6v_voltage_now(raw_val);
+		break;
+	default:
+		/* No processing for other channels so return raw value */
+		*val = raw_val;
+		break;
+	}
+
+	return IIO_VAL_INT;
+}
+
+static int da9150_gpadc_read_scale(int channel, int *val, int *val2)
+{
+	switch (channel) {
+	case DA9150_GPADC_CHAN_VBAT:
+		*val = 2932;
+		*val2 = 1000;
+		return IIO_VAL_FRACTIONAL;
+	case DA9150_GPADC_CHAN_TJUNC_CORE:
+	case DA9150_GPADC_CHAN_TJUNC_OVP:
+		*val = 1000000;
+		*val2 = 4420;
+		return IIO_VAL_FRACTIONAL;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int da9150_gpadc_read_offset(int channel, int *val)
+{
+	switch (channel) {
+	case DA9150_GPADC_CHAN_VBAT:
+		*val = 1500000 / 2932;
+		return IIO_VAL_INT;
+	case DA9150_GPADC_CHAN_TJUNC_CORE:
+	case DA9150_GPADC_CHAN_TJUNC_OVP:
+		*val = -144;
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int da9150_gpadc_read_raw(struct iio_dev *indio_dev,
+				 struct iio_chan_spec const *chan,
+				 int *val, int *val2, long mask)
+{
+	struct da9150_gpadc *gpadc = iio_priv(indio_dev);
+
+	if ((chan->channel < DA9150_GPADC_CHAN_GPIOA) ||
+	    (chan->channel > DA9150_GPADC_CHAN_TJUNC_OVP))
+		return -EINVAL;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+	case IIO_CHAN_INFO_PROCESSED:
+		return da9150_gpadc_read_processed(gpadc, chan->channel,
+						   chan->address, val);
+	case IIO_CHAN_INFO_SCALE:
+		return da9150_gpadc_read_scale(chan->channel, val, val2);
+	case IIO_CHAN_INFO_OFFSET:
+		return da9150_gpadc_read_offset(chan->channel, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info da9150_gpadc_info = {
+	.read_raw = &da9150_gpadc_read_raw,
+	.driver_module = THIS_MODULE,
+};
+
+#define DA9150_GPADC_CHANNEL(_id, _hw_id, _type, chan_info,	\
+			     _ext_name) {			\
+	.type = _type,						\
+	.indexed = 1,						\
+	.channel = DA9150_GPADC_CHAN_##_id,			\
+	.address = DA9150_GPADC_HW_CHAN_##_hw_id,		\
+	.info_mask_separate = chan_info,			\
+	.extend_name = _ext_name,				\
+	.datasheet_name = #_id,					\
+}
+
+#define DA9150_GPADC_CHANNEL_RAW(_id, _hw_id, _type, _ext_name)	\
+	DA9150_GPADC_CHANNEL(_id, _hw_id, _type,		\
+			     BIT(IIO_CHAN_INFO_RAW), _ext_name)
+
+#define DA9150_GPADC_CHANNEL_SCALED(_id, _hw_id, _type, _ext_name)	\
+	DA9150_GPADC_CHANNEL(_id, _hw_id, _type,			\
+			     BIT(IIO_CHAN_INFO_RAW) |			\
+			     BIT(IIO_CHAN_INFO_SCALE) |			\
+			     BIT(IIO_CHAN_INFO_OFFSET),			\
+			     _ext_name)
+
+#define DA9150_GPADC_CHANNEL_PROCESSED(_id, _hw_id, _type, _ext_name)	\
+	DA9150_GPADC_CHANNEL(_id, _hw_id, _type,			\
+			     BIT(IIO_CHAN_INFO_PROCESSED), _ext_name)
+
+/* Supported channels */
+static const struct iio_chan_spec da9150_gpadc_channels[] = {
+	DA9150_GPADC_CHANNEL_PROCESSED(GPIOA, GPIOA_6V, IIO_VOLTAGE, NULL),
+	DA9150_GPADC_CHANNEL_PROCESSED(GPIOB, GPIOB_6V, IIO_VOLTAGE, NULL),
+	DA9150_GPADC_CHANNEL_PROCESSED(GPIOC, GPIOC_6V, IIO_VOLTAGE, NULL),
+	DA9150_GPADC_CHANNEL_PROCESSED(GPIOD, GPIOD_6V, IIO_VOLTAGE, NULL),
+	DA9150_GPADC_CHANNEL_PROCESSED(IBUS, IBUS_SENSE, IIO_CURRENT, "ibus"),
+	DA9150_GPADC_CHANNEL_PROCESSED(VBUS, VBUS_DIV_, IIO_VOLTAGE, "vbus"),
+	DA9150_GPADC_CHANNEL_PROCESSED(VSYS, VSYS, IIO_VOLTAGE, "vsys"),
+	DA9150_GPADC_CHANNEL_SCALED(VBAT, VBAT, IIO_VOLTAGE, "vbat"),
+	DA9150_GPADC_CHANNEL_RAW(TBAT, TBAT, IIO_VOLTAGE, "tbat"),
+	DA9150_GPADC_CHANNEL_SCALED(TJUNC_CORE, TJUNC_CORE, IIO_TEMP,
+				    "tjunc_core"),
+	DA9150_GPADC_CHANNEL_SCALED(TJUNC_OVP, TJUNC_OVP, IIO_TEMP,
+				    "tjunc_ovp"),
+};
+
+/* Default maps used by da9150-charger */
+static struct iio_map da9150_gpadc_default_maps[] = {
+	{
+		.consumer_dev_name = "da9150-charger",
+		.consumer_channel = "CHAN_IBUS",
+		.adc_channel_label = "IBUS",
+	},
+	{
+		.consumer_dev_name = "da9150-charger",
+		.consumer_channel = "CHAN_VBUS",
+		.adc_channel_label = "VBUS",
+	},
+	{
+		.consumer_dev_name = "da9150-charger",
+		.consumer_channel = "CHAN_TJUNC",
+		.adc_channel_label = "TJUNC_CORE",
+	},
+	{
+		.consumer_dev_name = "da9150-charger",
+		.consumer_channel = "CHAN_VBAT",
+		.adc_channel_label = "VBAT",
+	},
+	{},
+};
+
+static int da9150_gpadc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct da9150 *da9150 = dev_get_drvdata(dev->parent);
+	struct da9150_gpadc *gpadc;
+	struct iio_dev *indio_dev;
+	int irq, ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*gpadc));
+	if (!indio_dev) {
+		dev_err(&pdev->dev, "Failed to allocate IIO device\n");
+		return -ENOMEM;
+	}
+	gpadc = iio_priv(indio_dev);
+
+	platform_set_drvdata(pdev, indio_dev);
+	gpadc->da9150 = da9150;
+	gpadc->dev = dev;
+	mutex_init(&gpadc->lock);
+	init_completion(&gpadc->complete);
+
+	irq = platform_get_irq_byname(pdev, "GPADC");
+	if (irq < 0) {
+		dev_err(dev, "Failed to get IRQ: %d\n", irq);
+		return irq;
+	}
+
+	ret = devm_request_threaded_irq(dev, irq, NULL, da9150_gpadc_irq,
+					IRQF_ONESHOT, "GPADC", gpadc);
+	if (ret) {
+		dev_err(dev, "Failed to request IRQ %d: %d\n", irq, ret);
+		return ret;
+	}
+
+	ret = iio_map_array_register(indio_dev, da9150_gpadc_default_maps);
+	if (ret) {
+		dev_err(dev, "Failed to register IIO maps: %d\n", ret);
+		return ret;
+	}
+
+	indio_dev->name = dev_name(dev);
+	indio_dev->dev.parent = dev;
+	indio_dev->dev.of_node = pdev->dev.of_node;
+	indio_dev->info = &da9150_gpadc_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = da9150_gpadc_channels;
+	indio_dev->num_channels = ARRAY_SIZE(da9150_gpadc_channels);
+
+	ret = iio_device_register(indio_dev);
+	if (ret) {
+		dev_err(dev, "Failed to register IIO device: %d\n", ret);
+		goto iio_map_unreg;
+	}
+
+	return 0;
+
+iio_map_unreg:
+	iio_map_array_unregister(indio_dev);
+
+	return ret;
+}
+
+static int da9150_gpadc_remove(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+
+	iio_device_unregister(indio_dev);
+	iio_map_array_unregister(indio_dev);
+
+	return 0;
+}
+
+static struct platform_driver da9150_gpadc_driver = {
+	.driver = {
+		.name = "da9150-gpadc",
+	},
+	.probe = da9150_gpadc_probe,
+	.remove = da9150_gpadc_remove,
+};
+
+module_platform_driver(da9150_gpadc_driver);
+
+MODULE_DESCRIPTION("GPADC Driver for DA9150");
+MODULE_AUTHOR("Adam Thomson <Adam.Thomson.Opensource@diasemi.com>");
+MODULE_LICENSE("GPL");