Re: [PATCH v2 3/7] iio: Add support for DA9150 GPADC

Peter Meerwald
2014-08-28T11:28:26Z

some minor comments inline

> This patch adds support for DA9150 Charger & Fuel-Gauge IC GPADC.
>
> Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
> ---
> drivers/iio/adc/Kconfig | 9 +
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/da9150-gpadc.c | 430 +++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 440 insertions(+)
> create mode 100644 drivers/iio/adc/da9150-gpadc.c
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 11b048a..8041347 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -127,6 +127,15 @@ config AT91_ADC
> help
> Say yes here to build support for Atmel AT91 ADC.
>
> +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 EXYNOS_ADC
> tristate "Exynos ADC driver support"
> depends on ARCH_EXYNOS || (OF && COMPILE_TEST)
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index ad81b51..48413d2 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -14,6 +14,7 @@ obj-$(CONFIG_AD7793) += ad7793.o
> obj-$(CONFIG_AD7887) += ad7887.o
> obj-$(CONFIG_AD799X) += ad799x.o
> obj-$(CONFIG_AT91_ADC) += at91_adc.o
> +obj-$(CONFIG_DA9150_GPADC) += da9150-gpadc.o
> obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o
> obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
> obj-$(CONFIG_MAX1027) += max1027.o
> diff --git a/drivers/iio/adc/da9150-gpadc.c b/drivers/iio/adc/da9150-gpadc.c
> new file mode 100644
> index 0000000..21a21a9
> --- /dev/null
> +++ b/drivers/iio/adc/da9150-gpadc.c
> @@ -0,0 +1,430 @@
> +/*
> + * 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/mfd/da9150/core.h>
> +#include <linux/mfd/da9150/pdata.h>
> +#include <linux/mfd/da9150/registers.h>
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/machine.h>
> +#include <linux/iio/driver.h>
> +
> +
> +/* Channels */
> +enum da9150_gpadc_hw_channel {
> + DA9150_GPADC_HW_CHAN_GPIOA_2V = 0,
> + DA9150_GPADC_HW_CHAN_GPIOA_2V_,

why the underscore_ notation?
couldn't you use e.g. DA9150_GPADC_HW_CHAN_GPIOB_2V = 2?

> + 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_5V,
> + DA9150_GPADC_HW_CHAN_GPIOA_5V_,
> + DA9150_GPADC_HW_CHAN_GPIOB_5V,
> + DA9150_GPADC_HW_CHAN_GPIOB_5V_,
> + DA9150_GPADC_HW_CHAN_GPIOC_5V,
> + DA9150_GPADC_HW_CHAN_GPIOC_5V_,
> + DA9150_GPADC_HW_CHAN_GPIOD_5V,
> + DA9150_GPADC_HW_CHAN_GPIOD_5V_,
> + 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_ID,
> + 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;
> +}
> +
> +int da9150_gpadc_read_adc(struct da9150_gpadc *gpadc, int hw_chan)

static?

> +{
> + 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 GP-ADC\n",

GPADC everywhere else

> + 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;

can't the read be done with a 16bit read?

> +
> + return result;
> +}
> +
> +static inline int da9150_gpadc_gpio_5v_voltage_now(int raw_val)
> +{
> + /* Convert to uV */
> + return (((6 * ((raw_val * 1000) + 500)) / 1024) * 1000);

outer parenthesis not needed, here and below

> +}
> +
> +static inline int da9150_gpadc_ibus_current_avg(int raw_val)
> +{
> + /* Convert to uA */
> + return (((4 * ((raw_val * 1000) + 500)) / 2048) * 1000);
> +}
> +
> +static inline int da9150_gpadc_vbus_21v_voltage_now(int raw_val)
> +{
> + /* Convert to uV */
> + return (((21 * ((raw_val * 1000) + 500)) / 1024) * 1000);
> +}
> +
> +static inline int da9150_gpadc_vsys_6v_voltage_now(int raw_val)
> +{
> + /* Convert to uV */
> + return (((3 * ((raw_val * 1000) + 500)) / 512) * 1000);
> +}
> +
> +static inline int da9150_gpadc_tjunc_temp(int raw_val)
> +{
> + /* Convert to 0.1 degrees C */

IIO wants mille degrees C

> + return (((879 - (1023 - raw_val)) * 10000) / 4420);
> +}
> +
> +static inline int da9150_gpadc_vbat_voltage_now(int raw_val)
> +{
> + /* Convert to uV */
> + return ((2932 * raw_val) + 1500000);
> +}
> +
> +int da9150_gpadc_read_processed(struct da9150_gpadc *gpadc, int channel,
> + int hw_chan)

static?

> +{
> + int raw_val, ret;
> +
> + 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:
> + ret = da9150_gpadc_gpio_5v_voltage_now(raw_val);

could return directly ...

> + break;
> + case DA9150_GPADC_CHAN_IBUS:
> + ret = da9150_gpadc_ibus_current_avg(raw_val);
> + break;
> + case DA9150_GPADC_CHAN_VBUS:
> + ret = da9150_gpadc_vbus_21v_voltage_now(raw_val);
> + break;
> + case DA9150_GPADC_CHAN_VSYS:
> + ret = da9150_gpadc_vsys_6v_voltage_now(raw_val);
> + break;
> + case DA9150_GPADC_CHAN_TJUNC_CORE:
> + case DA9150_GPADC_CHAN_TJUNC_OVP:
> + ret = da9150_gpadc_tjunc_temp(raw_val);
> + break;
> + default:
> + /* No processing for other channels so return raw value */
> + ret = raw_val;
> + break;
> + }

and save the final return
> +
> + return ret;
> +}
> +
> +int da9150_gpadc_read_scale(int channel)

static?

> +{
> + int ret;
> +
> + switch (channel) {
> + case DA9150_GPADC_CHAN_VBAT:
> + ret = 2932;

return directly?

> + break;
> + default:
> + ret = -EINVAL;
> + }
> +
> + return ret;
> +}
> +
> +int da9150_gpadc_read_offset(int channel)
> +{
> + int ret;
> +
> + switch (channel) {
> + case DA9150_GPADC_CHAN_VBAT:
> + ret = 1500000 / 2932;

return directly?

> + break;
> + default:
> + ret = -EINVAL;
> + }
> +
> + return ret;
> +}
> +
> +int da9150_gpadc_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)

static?

> +{
> + struct da9150_gpadc *gpadc = iio_priv(indio_dev);
> + int ret;
> +
> + 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:
> + ret = da9150_gpadc_read_processed(gpadc, chan->channel,
> + chan->address);
> + break;
> + case IIO_CHAN_INFO_SCALE:
> + ret = da9150_gpadc_read_scale(chan->channel);
> + break;
> + case IIO_CHAN_INFO_OFFSET:
> + ret = da9150_gpadc_read_offset(chan->channel);
> + break;
> + default:
> + ret = -EINVAL;
> + break;
> + }
> +
> + if (ret < 0)
> + return ret;
> +
> + *val = ret;
> +
> + return IIO_VAL_INT;
> +}
> +
> +static const struct iio_info da9150_gpadc_info = {
> + .read_raw = &da9150_gpadc_read_raw,
> + .driver_module = THIS_MODULE,
> +};
> +
> +#define GPADC_CHANNEL(_id, _hw_id, _type, chan_info, _ext_name) { \
> + .type = _type, \
> + .indexed = 1, \

there is only one current channel, it should not be indexed

> + .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 GPADC_CHANNEL_RAW(_id, _hw_id, _type, _ext_name) \
> + GPADC_CHANNEL(_id, _hw_id, _type, BIT(IIO_CHAN_INFO_RAW), _ext_name)
> +
> +#define GPADC_CHANNEL_SCALED(_id, _hw_id, _type, _ext_name) \
> + GPADC_CHANNEL(_id, _hw_id, _type, \
> + BIT(IIO_CHAN_INFO_RAW) | \
> + BIT(IIO_CHAN_INFO_SCALE) | \
> + BIT(IIO_CHAN_INFO_OFFSET), \
> + _ext_name)
> +
> +#define GPADC_CHANNEL_PROCESSED(_id, _hw_id, _type, _ext_name) \
> + GPADC_CHANNEL(_id, _hw_id, _type, BIT(IIO_CHAN_INFO_PROCESSED), \
> + _ext_name)
> +
> +/* Supported channels */
> +static const struct iio_chan_spec da9150_gpadc_channels[] = {
> + GPADC_CHANNEL_PROCESSED(GPIOA, GPIOA_5V, IIO_VOLTAGE, "GPIOA"),
> + GPADC_CHANNEL_PROCESSED(GPIOB, GPIOB_5V, IIO_VOLTAGE, "GPIOB"),
> + GPADC_CHANNEL_PROCESSED(GPIOC, GPIOC_5V, IIO_VOLTAGE, "GPIOC"),
> + GPADC_CHANNEL_PROCESSED(GPIOD, GPIOD_5V, IIO_VOLTAGE, "GPIOD"),
> + GPADC_CHANNEL_PROCESSED(IBUS, IBUS_SENSE, IIO_CURRENT, "IBUS"),
> + GPADC_CHANNEL_PROCESSED(VBUS, VBUS_DIV_, IIO_VOLTAGE, "VBUS"),
> + GPADC_CHANNEL_RAW(ID, ID, IIO_VOLTAGE, "ID"),
> + GPADC_CHANNEL_PROCESSED(VSYS, VSYS, IIO_VOLTAGE, "VSYS"),
> + GPADC_CHANNEL_SCALED(VBAT, VBAT, IIO_VOLTAGE, "VBAT"),
> + GPADC_CHANNEL_RAW(TBAT, TBAT, IIO_VOLTAGE, "TBAT"),
> + GPADC_CHANNEL_PROCESSED(TJUNC_CORE, TJUNC_CORE, IIO_TEMP, "TJUNC_CORE"),
> + GPADC_CHANNEL_PROCESSED(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 ret;
> +
> + indio_dev = devm_iio_device_alloc(&pdev->dev,
> + sizeof(struct da9150_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;
> +
> + ret = iio_map_array_register(indio_dev, da9150_gpadc_default_maps);
> + if (ret) {
> + dev_err(dev, "Failed to register IIO maps: %d\n", ret);
> + goto iio_map_fail;

just return here?

> + }
> +
> + mutex_init(&gpadc->lock);
> + init_completion(&gpadc->complete);
> +
> + /* Register IRQ */
> + ret = da9150_register_irq(pdev, gpadc, da9150_gpadc_irq, "GPADC");
> + if (ret < 0)
> + goto irq_fail;
> +
> + 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_dev_fail;
> + }
> +
> + return ret;
> +
> +iio_dev_fail:
> +irq_fail:

why two labels?

> + iio_map_array_unregister(indio_dev);
> +
> +iio_map_fail:
> + return ret;
> +}
> +
> +static int da9150_gpadc_remove(struct platform_device *pdev)
> +{
> + struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> +
> + iio_map_array_unregister(indio_dev);

unregister irq?

> + iio_device_unregister(indio_dev);
> +
> + return 0;
> +}
> +
> +static struct platform_driver da9150_gpadc_driver = {
> + .driver = {
> + .name = "da9150-gpadc",
> + .owner = THIS_MODULE,
> + },
> + .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");
> --
> 1.9.3
>
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--

Peter Meerwald
+43-664-2444418 (mobile)