Re: [NEW DRIVER V5 2/7] drivers/iio/adc: DA9058 ADC driver

From: Lars-Peter Clausen
Date: Thu Apr 18 2013 - 11:11:08 EST

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In reply to: Anthony Olech: "[NEW DRIVER V5 2/7] drivers/iio/adc: DA9058 ADC driver"
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Hi,

Looks almost good.

The patch subject prefix should be 'iio:adc:'. Different subsystems use
different styles for the subject prefix, so it's always to run a short git
log on the subsystems folder and take a look at what was used in the past.

On 04/17/2013 06:33 PM, Anthony Olech wrote:
> This patch is relative to linux next-20130417
>
> This is the ADC component driver of the Dialog DA9058 PMIC.
> This driver is just one component of the whole DA9058 PMIC
> driver. It depends on the DA9058 CORE component driver.
> The HWMON component driver depends on this ADC component driver.
>
> This component driver recieves the actual platform data from
> the DA9058 CORE driver, whose settings may be overridden from
> the platform data supplied from the machine driver.
>
> Changes relative to V4 of this patch:
> - rebased to latest tagged linux-next - previously relative to mainline
> drivers/iio/adc/Kconfig
> - removed dependancy on IIO_BUFFER, IIO_KFIFO_BUF and IIO_TRIGGER
> - added dependancy on MFD_DA9058
> - changed wait_for_completion_timeout to wait_for_completion_interruptible_timeout
> - added blank line before static function declaration
> - removed IIO_CHAN_INFO_SCALE
> - marked struct da9058_adc_channels as static const
> - changed to prefered style of nested struct instantiation
> - change to .info_mask_separate in struct instantiation
> - remove scan_mask
> - removed clearing of platform_set_drvdata
>
> Signed-off-by: Anthony Olech <anthony.olech.opensource@xxxxxxxxxxx>
> Signed-off-by: David Dajun Chen <david.chen@xxxxxxxxxxx>
> ---
> drivers/iio/adc/Kconfig | 12 ++
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/da9058-adc.c | 397 ++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 410 insertions(+)
> create mode 100644 drivers/iio/adc/da9058-adc.c
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index ab0767e6..68162bf 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -111,6 +111,18 @@ config EXYNOS_ADC
> of SoCs for drivers such as the touchscreen and hwmon to use to share
> this resource.
>
> +config DA9058_ADC
> + tristate "Dialog DA9058 PMIC ADC"
> + depends on MFD_DA9058
> + select SYSFS
> + help
> + Say yes here to build support for the ADC component of
> + the DAILOG DA9058 PMIC.
> + If unsure, say N (but it's safe to say "Y").
> +
> + To compile this driver as a module, choose M here: the
> + module will be called da9058-adc.
> +

This should go above the EXYNOS_ADC entry to keep it sorted.

> config LP8788_ADC
> bool "LP8788 ADC driver"
> depends on MFD_LP8788
[...]
> diff --git a/drivers/iio/adc/da9058-adc.c b/drivers/iio/adc/da9058-adc.c
> new file mode 100644
> index 0000000..d0ff431
> --- /dev/null
> +++ b/drivers/iio/adc/da9058-adc.c
> @@ -0,0 +1,397 @@
> +/*
> + * Copyright (C) 2012 Dialog Semiconductor Ltd.
> + *
> + * 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/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/iio/iio.h>
> +#include <linux/regmap.h>

The driver doesn't use anything from regmap.h as far as I can see

> +#include <linux/mfd/core.h>
> +
> +#include <linux/mfd/da9058/version.h>
> +#include <linux/mfd/da9058/core.h>
> +#include <linux/mfd/da9058/registers.h>
> +#include <linux/mfd/da9058/irq.h>
> +#include <linux/mfd/da9058/pdata.h>
> +#include <linux/mfd/da9058/adc.h>
> +#include <linux/mfd/da9058/conf.h>
> +
> +struct da9058_adc {
> + struct da9058 *da9058;
> + struct platform_device *pdev;
> + struct rtc_device *rtc_dev;

rtc_device? ;)

> + int use_automatic_adc;
> + int irq;
> +};
> +
> +/*
> + * if the PMIC is in automatic ADC consersion mode we have the choice
> + * of just getting the last (automatic) conversion or doing a manual
> + * conversion anyway.
> + *
> + * if the PMIC is not in automatic ADC consersion mode we have no choice
> + * we just have to ignore the requested mode and just do a manual
> + * ADC conversion.
> + */
> +static int da9058_automatic_adc_conversion(struct da9058 *da9058,
> + const int channel, unsigned int *value)
> +{
> + unsigned int adc_msh, adc_lsh;
> + int ret;
> +
> + switch (channel) {
> + case DA9058_ADCMAN_MUXSEL_VBAT:
> + ret = da9058_reg_read(da9058, DA9058_VBATRES_REG_MSB,
> + &adc_msh);
> + if (ret)
> + return ret;
> +
> + ret = da9058_reg_read(da9058, DA9058_AUTORES_REG_1,
> + &adc_lsh);
> + if (ret)
> + return ret;
> +
> + *value = (adc_lsh & 0x0F) | (adc_msh << 4);
> +
> + return 0;
> + case DA9058_ADCMAN_MUXSEL_TEMP:
> + ret = da9058_reg_read(da9058, DA9058_TEMPRES_REG_MSB,
> + &adc_msh);
> + if (ret)
> + return ret;
> +
> + ret = da9058_reg_read(da9058, DA9058_AUTORES_REG_1,
> + &adc_lsh);
> + if (ret)
> + return ret;
> +
> + *value = (adc_lsh >> 4) | (adc_msh << 4);
> +
> + return 0;
> + case DA9058_ADCMAN_MUXSEL_VF:
> + ret = da9058_reg_read(da9058, DA9058_VREF_REG,
> + &adc_msh);
> + if (ret)
> + return ret;
> +
> + ret = da9058_reg_read(da9058, DA9058_AUTORES_REG_2,
> + &adc_lsh);
> + if (ret)
> + return ret;
> +
> + *value = (adc_lsh & 0x0F) | (adc_msh << 4);
> +
> + return 0;
> + case DA9058_ADCMAN_MUXSEL_ADCIN:
> + ret = da9058_reg_read(da9058, DA9058_ADCINRES_REG_MSB,
> + &adc_msh);
> + if (ret)
> + return ret;
> +
> + ret = da9058_reg_read(da9058, DA9058_AUTORES_REG_2,
> + &adc_lsh);
> + if (ret)
> + return ret;
> +
> + *value = (adc_lsh >> 4) | (adc_msh << 4);
> +
> + return 0;
> + case DA9058_ADCMAN_MUXSEL_TJUNC:
> + ret = da9058_reg_read(da9058, DA9058_TJUNCRES_REG,
> + &adc_msh);
> + if (ret)
> + return ret;
> +
> + ret = da9058_reg_read(da9058, DA9058_AUTORES_REG_3,
> + &adc_lsh);
> + if (ret)
> + return ret;
> +
> + *value = (adc_lsh >> 4) | (adc_msh << 4);
> +
> + return 0;

Same comment as last time, this is pretty much the same code over and over
again. Please put it in a common helper function.

> + default:
> + dev_err(da9058->dev, "ADC Channel %d is reserved\n", channel);
> + return -EIO;
> + }
> +}
> +
> +static int da9058_manual_adc_conversion(struct da9058 *da9058,
> + const int channel, unsigned int *value)
> +{
> + unsigned int adc_msh, adc_lsh;
> + int ret;
> +
> + mutex_lock(&da9058->adc_mutex);

Adding

INIT_COMPLETION(&st->completion);

shouldn't hurt

> +
> + ret = da9058_reg_write(da9058, DA9058_ADCMAN_REG,
> + DA9058_ADCMAN_MANCONV | channel);
> + if (ret < 0)
> + goto err;
> +
> + if (!wait_for_completion_interruptible_timeout(&da9058->adc_read_done,
> + msecs_to_jiffies(500))) {

You need to handle the case where this function is interrupted in which case
it returns a negative error which should be passed on to the caller.

> + dev_err(da9058->dev,
> + "timeout waiting for ADC conversion interrupt\n");
> + ret = -ETIMEDOUT;
> + goto err;
> + }
> +
> + ret = da9058_reg_read(da9058, DA9058_ADCRESH_REG, &adc_msh);
> + if (ret < 0)
> + goto err;
> +
> + ret = da9058_reg_read(da9058, DA9058_ADCRESL_REG, &adc_lsh);
> + if (ret < 0)
> + goto err;
> +
> + *value = (adc_msh << 4) | (adc_lsh & 0x0F);
> +

And here it is again.

> +err:
> + mutex_unlock(&da9058->adc_mutex);
> + return ret;
> +}
> +
> +static int da9058_adc_conversion_read(struct da9058 *da9058, const int channel,
> + int automatic_mode, unsigned int *value)
> +{
> + if (!value)
> + return -EINVAL;
> +
> + if (automatic_mode) {
> + unsigned int adc_ctrl;
> + int ret;
> +
> + ret = da9058_reg_read(da9058, DA9058_ADCCONT_REG, &adc_ctrl);
> + if (ret)
> + return ret;
> +
> + if (adc_ctrl & DA9058_ADCCONT_AUTOADCEN)
> + return da9058_automatic_adc_conversion(da9058,
> + channel, value);
> + else
> + return da9058_manual_adc_conversion(da9058,
> + channel, value);
> + } else {
> + return da9058_manual_adc_conversion(da9058, channel, value);
> + }
> +}
> +
[...]
> +static int da9058_adc_read_raw(struct iio_dev *idev,
> + struct iio_chan_spec const *chan, int *val, int *val2, long info)
> +{
> + struct da9058_adc *adc = iio_priv(idev);
> + struct da9058 *da9058 = adc->da9058;
> + int ret;
> +
> + switch (info) {
> + case IIO_CHAN_INFO_RAW:
> + ret = da9058_adc_conversion_read(da9058, chan->channel,
> + adc->use_automatic_adc, val);
> + if (ret)
> + return ret;
> + else
> + return IIO_VAL_INT;

Just a codestyle nitpick. I'd drop the else.

> + default:
> + return -EINVAL;
> + };
> +}
[...]
> +static const struct iio_chan_spec da9058_adc_channels[] = {
> + {
> + .type = IIO_VOLTAGE,
> + .indexed = 1,
> + .channel = 0,
> + .scan_index = 0,
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 12,
> + .storagebits = 16,
> + },
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> + },
> + {
> + .type = IIO_VOLTAGE,
> + .indexed = 1,
> + .channel = 1,
> + .scan_index = 1,
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 12,
> + .storagebits = 16,
> + },
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> + },
> + {
> + .type = IIO_VOLTAGE,
> + .indexed = 1,
> + .channel = 2,
> + .scan_index = 2,
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 12,
> + .storagebits = 16,
> + },
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> + },
> + {
> + .type = IIO_VOLTAGE,
> + .indexed = 1,
> + .channel = 3,
> + .scan_index = 3,
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 12,
> + .storagebits = 16,
> + },
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> + },
> + {
> + .type = IIO_VOLTAGE,
> + .indexed = 1,
> + .channel = 4,
> + .scan_index = 4,
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 12,
> + .storagebits = 16,
> + },
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),

Same comment as last time. Use a helper macro to initialize the channels.

> + },
> +
> +};
> +
> +static int da9058_adc_probe(struct platform_device *pdev)
> +{
> + struct da9058 *da9058 = dev_get_drvdata(pdev->dev.parent);
> + const struct mfd_cell *cell = mfd_get_cell(pdev);
> + struct da9058_adc_pdata *adc_pdata;
> + struct da9058_adc *adc;
> + struct iio_dev *idev;

I know this is really nitpicking, but same comment as before indio_dev
instead of idev to be consistent with other drivers.

[...]
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Next message: Johannes Weiner: "Re: [PATCH 05/10] mm: vmscan: Do not allow kswapd to scan at maximumpriority"
Previous message: Johannes Weiner: "Re: [PATCH 04/10] mm: vmscan: Decide whether to compact the pgdatbased on reclaim progress"
In reply to: Anthony Olech: "[NEW DRIVER V5 2/7] drivers/iio/adc: DA9058 ADC driver"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]