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>

3 files changed, 417 insertions, 0 deletions

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 202daf889be2..fc6f90614218 100644
--- a/drivers/iio/adc/Kconfig
+++ b/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
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 0315af640866..3930e63e84bc 100644
--- a/drivers/iio/adc/Makefile
+++ b/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
diff --git a/drivers/iio/adc/da9150-gpadc.c b/drivers/iio/adc/da9150-gpadc.c
new file mode 100644
index 000000000000..3445107e10b7
--- /dev/null
+++ b/drivers/iio/adc/da9150-gpadc.c
@@ -0,0 +1,407 @@
+/*
+ * 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");