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SubjectRe: [PATCH 2/4] iio: dac: add support for stm32 DAC
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On 05/04/17 16:48, Fabrice Gasnier wrote:
> On 04/02/2017 01:32 PM, Jonathan Cameron wrote:
>> On 31/03/17 12:45, Fabrice Gasnier wrote:
>>> Add support for STMicroelectronics STM32 DAC. It's a 12-bit, voltage
>>> output digital-to-analog converter. It has two output channels, each
>>> with its own converter.
>>> It supports 8 bits or 12bits left/right aligned data format. Only
>>> 12bits right-aligned is used here. It has built-in noise or
>>> triangle waveform generator, and supports external triggers for
>>> conversions.
>>> Each channel can be used independently, with separate trigger, then
>>> separate IIO devices are used to handle this. Core driver is intended
>>> to share common resources such as clock, reset, reference voltage and
>>> registers.
>>>
>>> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
>> Annoyingly my laptop just crashed mid way through reviewing this..
>>
> Hi Jonathan,
> I hope I have nothing to do with this ;-)
>
>> Ah well, hopefully I'll remember everything (there wasn't much).
>>
>> For DACs the 'enable' attribute is not normally used. Rather we
>> use the powerdown one. The reasoning being that we care about what
>> the state is when it is powered down. Even if that isn't controllable
>> I would expect to see it exported as powerdown_mode with a fixed value.
>>
> Ok, I'll try to use powerdown_mode in V2 as other DACs do. For now,
> basically, I'll remap same functionality as 'enable' of this patch.
>
> What do you mean by 'fixed value' ?
Read only with only one value.
>
> But, this also raise me one question:
> Current patch use 'enable' to set EN bits in control register. Then, DAC
> output goes from Hi-Z to buffered output.
> There is also other power modes available. One of them is 'unbuffered':
> output buffer can be disabled/bypassed.
> This typically can save power, but it only makes sense to use it
> depending on output load impedance (This is explained in AN3126 as you
> pointed out in later patch).
> Current patch uses buffered output (which suits all needs regarding
> output load impedance). And the question is...
>
> Should I expose this power modes to userland by using 'powerdown_mode' ?
>
> OR... I'd rather rely on a dt property like st,dac-output-mode to manage
> this, because buffered/unbuffered output modes depends on HW output load
> impedance. Do you agree with this approach to use:
> - powerdown_mode as Hi-Z / enable switch, with dedicated dt property to
> set output power mode ?
Yes. If it's hardware dependant like this it belongs in dt to my mind.
>
> Please let me know your opinion.
>
> But, I think this can be part of another patchset...
Absolutely. No need to support all the bells and whistles
from the start!
>
>> Other than that - looks pretty good to me.
>>
>> Jonathan
>>
>>> ---
>>> drivers/iio/dac/Kconfig | 15 ++
>>> drivers/iio/dac/Makefile | 2 +
>>> drivers/iio/dac/stm32-dac-core.c | 180 ++++++++++++++++++++++++
>>> drivers/iio/dac/stm32-dac-core.h | 51 +++++++
>>> drivers/iio/dac/stm32-dac.c | 296 +++++++++++++++++++++++++++++++++++++++
>>> 5 files changed, 544 insertions(+)
>>> create mode 100644 drivers/iio/dac/stm32-dac-core.c
>>> create mode 100644 drivers/iio/dac/stm32-dac-core.h
>>> create mode 100644 drivers/iio/dac/stm32-dac.c
>>>
>>> diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
>>> index d3084028..7198648 100644
>>> --- a/drivers/iio/dac/Kconfig
>>> +++ b/drivers/iio/dac/Kconfig
>>> @@ -274,6 +274,21 @@ config MCP4922
>>> To compile this driver as a module, choose M here: the module
>>> will be called mcp4922.
>>>
>>> +config STM32_DAC
>>> + tristate "STMicroelectronics STM32 DAC"
>>> + depends on (ARCH_STM32 && OF) || COMPILE_TEST
>>> + depends on REGULATOR
>>> + select STM32_DAC_CORE
>>> + help
>>> + Say yes here to build support for STMicroelectronics STM32 Digital
>>> + to Analog Converter (DAC).
>>> +
>>> + This driver can also be built as a module. If so, the module
>>> + will be called stm32-dac.
>>> +
>>> +config STM32_DAC_CORE
>>> + tristate
>>> +
>>> config VF610_DAC
>>> tristate "Vybrid vf610 DAC driver"
>>> depends on OF
>>> diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
>>> index f01bf4a..afe8ae7 100644
>>> --- a/drivers/iio/dac/Makefile
>>> +++ b/drivers/iio/dac/Makefile
>>> @@ -29,4 +29,6 @@ obj-$(CONFIG_MAX517) += max517.o
>>> obj-$(CONFIG_MAX5821) += max5821.o
>>> obj-$(CONFIG_MCP4725) += mcp4725.o
>>> obj-$(CONFIG_MCP4922) += mcp4922.o
>>> +obj-$(CONFIG_STM32_DAC_CORE) += stm32-dac-core.o
>>> +obj-$(CONFIG_STM32_DAC) += stm32-dac.o
>>> obj-$(CONFIG_VF610_DAC) += vf610_dac.o
>>> diff --git a/drivers/iio/dac/stm32-dac-core.c b/drivers/iio/dac/stm32-dac-core.c
>>> new file mode 100644
>>> index 0000000..75e4878
>>> --- /dev/null
>>> +++ b/drivers/iio/dac/stm32-dac-core.c
>>> @@ -0,0 +1,180 @@
>>> +/*
>>> + * This file is part of STM32 DAC driver
>>> + *
>>> + * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
>>> + * Author: Fabrice Gasnier <fabrice.gasnier@st.com>.
>>> + *
>>> + * License type: GPLv2
>>> + *
>>> + * This program is free software; you can redistribute it and/or modify it
>>> + * under the terms of the GNU General Public License version 2 as published by
>>> + * the Free Software Foundation.
>>> + *
>>> + * This program is distributed in the hope that it will be useful, but
>>> + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
>>> + * or FITNESS FOR A PARTICULAR PURPOSE.
>>> + * See the GNU General Public License for more details.
>>> + *
>>> + * You should have received a copy of the GNU General Public License along with
>>> + * this program. If not, see <http://www.gnu.org/licenses/>.
>>> + */
>>> +
>>> +#include <linux/clk.h>
>>> +#include <linux/delay.h>
>>> +#include <linux/module.h>
>>> +#include <linux/of_platform.h>
>>> +#include <linux/regulator/consumer.h>
>>> +#include <linux/reset.h>
>>> +
>>> +#include "stm32-dac-core.h"
>>> +
>>> +/**
>>> + * struct stm32_dac_priv - stm32 DAC core private data
>>> + * @pclk: peripheral clock common for all DACs
>>> + * @rst: peripheral reset control
>>> + * @vref: regulator reference
>>> + * @common: Common data for all DAC instances
>>> + */
>>> +struct stm32_dac_priv {
>>> + struct clk *pclk;
>>> + struct reset_control *rst;
>>> + struct regulator *vref;
>>> + struct stm32_dac_common common;
>>> +};
>>> +
>>> +static struct stm32_dac_priv *to_stm32_dac_priv(struct stm32_dac_common *com)
>>> +{
>>> + return container_of(com, struct stm32_dac_priv, common);
>>> +}
>>> +
>>> +static const struct regmap_config stm32_dac_regmap_cfg = {
>>> + .reg_bits = 32,
>>> + .val_bits = 32,
>>> + .reg_stride = sizeof(u32),
>>> + .max_register = 0x3fc,
>>> +};
>>> +
>>> +static int stm32_dac_probe(struct platform_device *pdev)
>>> +{
>>> + struct device *dev = &pdev->dev;
>>> + struct stm32_dac_priv *priv;
>>> + struct regmap *regmap;
>>> + struct resource *res;
>>> + void __iomem *mmio;
>>> + int ret;
>>> +
>>> + if (!dev->of_node)
>>> + return -ENODEV;
>>> +
>>> + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
>>> + if (!priv)
>>> + return -ENOMEM;
>>> +
>>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> + mmio = devm_ioremap_resource(dev, res);
>>> + if (IS_ERR(mmio))
>>> + return PTR_ERR(mmio);
>>> +
>>> + regmap = devm_regmap_init_mmio(dev, mmio, &stm32_dac_regmap_cfg);
>>> + if (IS_ERR(regmap))
>>> + return PTR_ERR(regmap);
>>> + priv->common.regmap = regmap;
>>> +
>>> + priv->vref = devm_regulator_get(dev, "vref");
>>> + if (IS_ERR(priv->vref)) {
>>> + ret = PTR_ERR(priv->vref);
>>> + dev_err(dev, "vref get failed, %d\n", ret);
>>> + return ret;
>>> + }
>>> +
>>> + ret = regulator_enable(priv->vref);
>>> + if (ret < 0) {
>>> + dev_err(dev, "vref enable failed\n");
>>> + return ret;
>>> + }
>>> +
>>> + ret = regulator_get_voltage(priv->vref);
>>> + if (ret < 0) {
>>> + dev_err(dev, "vref get voltage failed, %d\n", ret);
>>> + goto err_vref;
>>> + }
>>> + priv->common.vref_mv = ret / 1000;
>>> + dev_dbg(dev, "vref+=%dmV\n", priv->common.vref_mv);
>>> +
>>> + priv->pclk = devm_clk_get(dev, "pclk");
>>> + if (IS_ERR(priv->pclk)) {
>>> + ret = PTR_ERR(priv->pclk);
>>> + dev_err(dev, "pclk get failed\n");
>>> + goto err_vref;
>>> + }
>>> +
>>> + ret = clk_prepare_enable(priv->pclk);
>>> + if (ret < 0) {
>>> + dev_err(dev, "pclk enable failed\n");
>>> + goto err_vref;
>>> + }
>>> +
>>> + priv->rst = devm_reset_control_get(dev, NULL);
>>> + if (!IS_ERR(priv->rst)) {
>>> + reset_control_assert(priv->rst);
>>> + udelay(2);
>>> + reset_control_deassert(priv->rst);
>>> + }
>>> +
>>> + /* When clock speed is higher than 80MHz, set HFSEL */
>>> + priv->common.hfsel = (clk_get_rate(priv->pclk) > 80000000UL);
>>> + ret = regmap_update_bits(regmap, STM32_DAC_CR, STM32H7_DAC_CR_HFSEL,
>>> + priv->common.hfsel ? STM32H7_DAC_CR_HFSEL : 0);
>>> + if (ret)
>>> + goto err_pclk;
>>> +
>>> + platform_set_drvdata(pdev, &priv->common);
>>> +
>>> + ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, dev);
>>> + if (ret < 0) {
>>> + dev_err(dev, "failed to populate DT children\n");
>>> + goto err_pclk;
>>> + }
>>> +
>>> + return 0;
>>> +
>>> +err_pclk:
>>> + clk_disable_unprepare(priv->pclk);
>>> +err_vref:
>>> + regulator_disable(priv->vref);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static int stm32_dac_remove(struct platform_device *pdev)
>>> +{
>>> + struct stm32_dac_common *common = platform_get_drvdata(pdev);
>>> + struct stm32_dac_priv *priv = to_stm32_dac_priv(common);
>>> +
>>> + of_platform_depopulate(&pdev->dev);
>>> + clk_disable_unprepare(priv->pclk);
>>> + regulator_disable(priv->vref);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static const struct of_device_id stm32_dac_of_match[] = {
>>> + { .compatible = "st,stm32h7-dac-core", },
>>> + {},
>>> +};
>>> +MODULE_DEVICE_TABLE(of, stm32_dac_of_match);
>>> +
>>> +static struct platform_driver stm32_dac_driver = {
>>> + .probe = stm32_dac_probe,
>>> + .remove = stm32_dac_remove,
>>> + .driver = {
>>> + .name = "stm32-dac-core",
>>> + .of_match_table = stm32_dac_of_match,
>>> + },
>>> +};
>>> +module_platform_driver(stm32_dac_driver);
>>> +
>>> +MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
>>> +MODULE_DESCRIPTION("STMicroelectronics STM32 DAC core driver");
>>> +MODULE_LICENSE("GPL v2");
>>> +MODULE_ALIAS("platform:stm32-dac-core");
>>> diff --git a/drivers/iio/dac/stm32-dac-core.h b/drivers/iio/dac/stm32-dac-core.h
>>> new file mode 100644
>>> index 0000000..d3099f7
>>> --- /dev/null
>>> +++ b/drivers/iio/dac/stm32-dac-core.h
>>> @@ -0,0 +1,51 @@
>>> +/*
>>> + * This file is part of STM32 DAC driver
>>> + *
>>> + * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
>>> + * Author: Fabrice Gasnier <fabrice.gasnier@st.com>.
>>> + *
>>> + * License type: GPLv2
>>> + *
>>> + * This program is free software; you can redistribute it and/or modify it
>>> + * under the terms of the GNU General Public License version 2 as published by
>>> + * the Free Software Foundation.
>>> + *
>>> + * This program is distributed in the hope that it will be useful, but
>>> + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
>>> + * or FITNESS FOR A PARTICULAR PURPOSE.
>>> + * See the GNU General Public License for more details.
>>> + *
>>> + * You should have received a copy of the GNU General Public License along with
>>> + * this program. If not, see <http://www.gnu.org/licenses/>.
>>> + */
>>> +
>>> +#ifndef __STM32_DAC_CORE_H
>>> +#define __STM32_DAC_CORE_H
>>> +
>>> +#include <linux/regmap.h>
>>> +
>>> +/* STM32 DAC registers */
>>> +#define STM32_DAC_CR 0x00
>>> +#define STM32_DAC_DHR12R1 0x08
>>> +#define STM32_DAC_DHR12R2 0x14
>>> +#define STM32_DAC_DOR1 0x2C
>>> +#define STM32_DAC_DOR2 0x30
>>> +
>>> +/* STM32_DAC_CR bit fields */
>>> +#define STM32_DAC_CR_EN1 BIT(0)
>>> +#define STM32H7_DAC_CR_HFSEL BIT(15)
>>> +#define STM32_DAC_CR_EN2 BIT(16)
>>> +
>>> +/**
>>> + * struct stm32_dac_common - stm32 DAC driver common data (for all instances)
>>> + * @regmap: DAC registers shared via regmap
>>> + * @vref_mv: reference voltage (mv)
>>> + * @hfsel: high speed bus clock
>>> + */
>>> +struct stm32_dac_common {
>>> + struct regmap *regmap;
>>> + int vref_mv;
>>> + bool hfsel;
>>> +};
>>> +
>>> +#endif
>>> diff --git a/drivers/iio/dac/stm32-dac.c b/drivers/iio/dac/stm32-dac.c
>>> new file mode 100644
>>> index 0000000..ee9711d
>>> --- /dev/null
>>> +++ b/drivers/iio/dac/stm32-dac.c
>>> @@ -0,0 +1,296 @@
>>> +/*
>>> + * This file is part of STM32 DAC driver
>>> + *
>>> + * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
>>> + * Authors: Amelie Delaunay <amelie.delaunay@st.com>
>>> + * Fabrice Gasnier <fabrice.gasnier@st.com>
>>> + *
>>> + * License type: GPLv2
>>> + *
>>> + * This program is free software; you can redistribute it and/or modify it
>>> + * under the terms of the GNU General Public License version 2 as published by
>>> + * the Free Software Foundation.
>>> + *
>>> + * This program is distributed in the hope that it will be useful, but
>>> + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
>>> + * or FITNESS FOR A PARTICULAR PURPOSE.
>>> + * See the GNU General Public License for more details.
>>> + *
>>> + * You should have received a copy of the GNU General Public License along with
>>> + * this program. If not, see <http://www.gnu.org/licenses/>.
>>> + */
>>> +
>>> +#include <linux/bitfield.h>
>>> +#include <linux/delay.h>
>>> +#include <linux/iio/iio.h>
>>> +#include <linux/kernel.h>
>>> +#include <linux/module.h>
>>> +#include <linux/platform_device.h>
>>> +
>>> +#include "stm32-dac-core.h"
>>> +
>>> +#define STM32_DAC_CHANNEL_1 1
>>> +#define STM32_DAC_CHANNEL_2 2
>>> +
>>> +/**
>>> + * struct stm32_dac - private data of DAC driver
>>> + * @common: reference to DAC common data
>>> + */
>>> +struct stm32_dac {
>>> + struct stm32_dac_common *common;
>>> +};
>>> +
>>> +static int stm32_dac_is_enabled(struct stm32_dac *dac, int channel)
>>> +{
>>> + u32 en, val;
>>> + int ret;
>>> +
>>> + ret = regmap_read(dac->common->regmap, STM32_DAC_CR, &val);
>>> + if (ret < 0)
>>> + return ret;
>>> + if (channel == STM32_DAC_CHANNEL_1)
>>> + en = FIELD_GET(STM32_DAC_CR_EN1, val);
>>> + else
>>> + en = FIELD_GET(STM32_DAC_CR_EN2, val);
>>> +
>>> + return !!en;
>>> +}
>>> +
>>> +static int stm32_dac_enable(struct iio_dev *indio_dev, int channel)
>>> +{
>>> + struct stm32_dac *dac = iio_priv(indio_dev);
>>> + u32 en = (channel == STM32_DAC_CHANNEL_1) ?
>>> + STM32_DAC_CR_EN1 : STM32_DAC_CR_EN2;
>>> + int ret;
>>> +
>>> + ret = regmap_update_bits(dac->common->regmap, STM32_DAC_CR, en, en);
>>> + if (ret < 0) {
>>> + dev_err(&indio_dev->dev, "Enable failed\n");
>>> + return ret;
>>> + }
>>> +
>>> + /*
>>> + * When HFSEL is set, it is not allowed to write the DHRx register
>>> + * during 8 clock cycles after the ENx bit is set. It is not allowed
>>> + * to make software/hardware trigger during this period neither.
>>> + */
>>> + if (dac->common->hfsel)
>>> + udelay(1);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int stm32_dac_disable(struct iio_dev *indio_dev, int channel)
>>> +{
>>> + struct stm32_dac *dac = iio_priv(indio_dev);
>>> + u32 en = (channel == STM32_DAC_CHANNEL_1) ?
>>> + STM32_DAC_CR_EN1 : STM32_DAC_CR_EN2;
>>> + int ret;
>>> +
>>> + ret = regmap_update_bits(dac->common->regmap, STM32_DAC_CR, en, 0);
>>> + if (ret)
>>> + dev_err(&indio_dev->dev, "Disable failed\n");
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static int stm32_dac_get_value(struct stm32_dac *dac, int channel, int *val)
>>> +{
>>> + int ret;
>>> +
>>> + if (channel == STM32_DAC_CHANNEL_1)
>>> + ret = regmap_read(dac->common->regmap, STM32_DAC_DOR1, val);
>>> + else
>>> + ret = regmap_read(dac->common->regmap, STM32_DAC_DOR2, val);
>>> +
>>> + return ret ? ret : IIO_VAL_INT;
>>> +}
>>> +
>>> +static int stm32_dac_set_value(struct stm32_dac *dac, int channel, int val)
>>> +{
>>> + int ret;
>>> +
>>> + if (channel == STM32_DAC_CHANNEL_1)
>>> + ret = regmap_write(dac->common->regmap, STM32_DAC_DHR12R1, val);
>>> + else
>>> + ret = regmap_write(dac->common->regmap, STM32_DAC_DHR12R2, val);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static int stm32_dac_read_raw(struct iio_dev *indio_dev,
>>> + struct iio_chan_spec const *chan,
>>> + int *val, int *val2, long mask)
>>> +{
>>> + struct stm32_dac *dac = iio_priv(indio_dev);
>>> + int ret;
>>> +
>>> + switch (mask) {
>>> + case IIO_CHAN_INFO_RAW:
>>> + return stm32_dac_get_value(dac, chan->channel, val);
>>> + case IIO_CHAN_INFO_SCALE:
>>> + *val = dac->common->vref_mv;
>>> + *val2 = chan->scan_type.realbits;
>>> + return IIO_VAL_FRACTIONAL_LOG2;
>>> + case IIO_CHAN_INFO_ENABLE:
>>> + ret = stm32_dac_is_enabled(dac, chan->channel);
>>> + if (ret < 0)
>>> + return ret;
>>> + *val = ret;
>>> + return IIO_VAL_INT;
>>> + default:
>>> + return -EINVAL;
>>> + }
>>> +}
>>> +
>>> +static int stm32_dac_write_raw(struct iio_dev *indio_dev,
>>> + struct iio_chan_spec const *chan,
>>> + int val, int val2, long mask)
>>> +{
>>> + struct stm32_dac *dac = iio_priv(indio_dev);
>>> +
>>> + switch (mask) {
>>> + case IIO_CHAN_INFO_RAW:
>>> + return stm32_dac_set_value(dac, chan->channel, val);
>>> + case IIO_CHAN_INFO_ENABLE:
>>> + if (!!val)
>>> + return stm32_dac_enable(indio_dev, chan->channel);
>>> + else
>>> + return stm32_dac_disable(indio_dev, chan->channel);
>>> + default:
>>> + return -EINVAL;
>>> + }
>>> +}
>>> +
>>> +static int stm32_dac_debugfs_reg_access(struct iio_dev *indio_dev,
>>> + unsigned reg, unsigned writeval,
>>> + unsigned *readval)
>>> +{
>>> + struct stm32_dac *dac = iio_priv(indio_dev);
>>> +
>>> + if (!readval)
>>> + return regmap_write(dac->common->regmap, reg, writeval);
>>> + else
>>> + return regmap_read(dac->common->regmap, reg, readval);
>>> +}
>>> +
>>> +static const struct iio_info stm32_dac_iio_info = {
>>> + .read_raw = &stm32_dac_read_raw,
>>> + .write_raw = &stm32_dac_write_raw,
>>> + .debugfs_reg_access = &stm32_dac_debugfs_reg_access,
>>> + .driver_module = THIS_MODULE,
>>> +};
>>> +
>>> +#define STM32_DAC_CHANNEL(chan, name) { \
>>> + .type = IIO_VOLTAGE, \
>>> + .indexed = 1, \
>>> + .output = 1, \
>>> + .channel = chan, \
>>> + .info_mask_separate = \
>>> + BIT(IIO_CHAN_INFO_RAW) | \
>>> + BIT(IIO_CHAN_INFO_ENABLE) | \
>>> + BIT(IIO_CHAN_INFO_SCALE), \
>>> + .scan_type = { \
>>> + .sign = 'u', \
>>> + .realbits = 12, \
>>> + .storagebits = 16, \
>>> + }, \
>>> + .datasheet_name = name, \
>>> +}
>>> +
>>> +static const struct iio_chan_spec stm32_dac_channels[] = {
>>> + STM32_DAC_CHANNEL(STM32_DAC_CHANNEL_1, "out1"),
>>> + STM32_DAC_CHANNEL(STM32_DAC_CHANNEL_2, "out2"),
>>> +};
>>> +
>>> +static int stm32_dac_chan_of_init(struct iio_dev *indio_dev)
>>> +{
>>> + struct device_node *np = indio_dev->dev.of_node;
>>> + unsigned int i;
>>> + u32 channel;
>>> + int ret;
>>> +
>>> + ret = of_property_read_u32(np, "st,dac-channel", &channel);
>>> + if (ret) {
>>> + dev_err(&indio_dev->dev, "Failed to read st,dac-channel\n");
>>> + return ret;
>>> + }
>>> +
>>> + for (i = 0; i < ARRAY_SIZE(stm32_dac_channels); i++) {
>>> + if (stm32_dac_channels[i].channel == channel)
>>> + break;
>>> + }
>>> + if (i >= ARRAY_SIZE(stm32_dac_channels)) {
>>> + dev_err(&indio_dev->dev, "Invalid st,dac-channel\n");
>>> + return -EINVAL;
>>> + }
>>> +
>>> + indio_dev->channels = &stm32_dac_channels[i];
>>> + indio_dev->num_channels = 1;
>>> +
>>> + return 0;
>>> +};
>>> +
>>> +static int stm32_dac_probe(struct platform_device *pdev)
>>> +{
>>> + struct device_node *np = pdev->dev.of_node;
>>> + struct iio_dev *indio_dev;
>>> + struct stm32_dac *dac;
>>> + int ret;
>>> +
>>> + if (!np)
>>> + return -ENODEV;
>>> +
>>> + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*dac));
>>> + if (!indio_dev)
>>> + return -ENOMEM;
>>> + platform_set_drvdata(pdev, indio_dev);
>>> +
>>> + dac = iio_priv(indio_dev);
>>> + dac->common = dev_get_drvdata(pdev->dev.parent);
>>> + indio_dev->name = dev_name(&pdev->dev);
>>> + indio_dev->dev.parent = &pdev->dev;
>>> + indio_dev->dev.of_node = pdev->dev.of_node;
>>> + indio_dev->info = &stm32_dac_iio_info;
>>> + indio_dev->modes = INDIO_DIRECT_MODE;
>>> +
>>> + ret = stm32_dac_chan_of_init(indio_dev);
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + ret = iio_device_register(indio_dev);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int stm32_dac_remove(struct platform_device *pdev)
>>> +{
>>> + struct iio_dev *indio_dev = platform_get_drvdata(pdev);
>>> +
>>> + iio_device_unregister(indio_dev);
>> use devm_iio_device_register and drop the remove entirely
>> (I guess this may make no sense once I've looked at later
>> patches however!)
> Good guess ;-)
> But okay, I'll use devm_ anyway, regardless of other patches.
>
> Thanks & Regards,
> Fabrice
>
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static const struct of_device_id stm32_dac_of_match[] = {
>>> + { .compatible = "st,stm32-dac", },
>>> + {},
>>> +};
>>> +MODULE_DEVICE_TABLE(of, stm32_dac_of_match);
>>> +
>>> +static struct platform_driver stm32_dac_driver = {
>>> + .probe = stm32_dac_probe,
>>> + .remove = stm32_dac_remove,
>>> + .driver = {
>>> + .name = "stm32-dac",
>>> + .of_match_table = stm32_dac_of_match,
>>> + },
>>> +};
>>> +module_platform_driver(stm32_dac_driver);
>>> +
>>> +MODULE_ALIAS("platform:stm32-dac");
>>> +MODULE_AUTHOR("Amelie Delaunay <amelie.delaunay@st.com>");
>>> +MODULE_DESCRIPTION("STMicroelectronics STM32 DAC driver");
>>> +MODULE_LICENSE("GPL v2");
>>>
>>
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