From: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
To: Ismail Kose <Ismail.Kose@maximintegrated.com>
Cc: jic23@kernel.org, knaack.h@gmx.de, lars@metafoo.de,
robh+dt@kernel.org, mark.rutland@arm.com, vilhelm.gray@gmail.com,
linus.walleij@linaro.org, jeff.dagenais@gmail.com,
fabrice.gasnier@st.com, gwenhael.goavec-merou@trabucayre.com,
peda@axentia.se, maxime.roussinbelanger@gmail.com,
ihkose@gmail.com, linux-iio@vger.kernel.org,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] iio: dac: DS4424: add Maxim DS4422/DS4424 DAC driver support
Date: Sun, 25 Jun 2017 23:33:57 +0200 (CEST) [thread overview]
Message-ID: <alpine.DEB.2.20.1706241114510.18383@vps.pmeerw.net> (raw)
In-Reply-To: <20170623230404.2283-1-Ismail.Kose@maximintegrated.com>
> Add iio driver for DS4422/DS4424 chips that support two/four channel 7-bit
> Sink/Source Current DAC.
minor comments below, on top of Jonathan's
> The driver supports device tree and platfrom files for the configurations.
platform
> Datasheet publicly available at:
> https://datasheets.maximintegrated.com/en/ds/DS4422-DS4424.pdf
>
> Signed-off-by: Ismail Kose <Ismail.Kose@maximintegrated.com>
> ---
> .../devicetree/bindings/iio/dac/ds4424.txt | 41 ++
> drivers/iio/dac/Kconfig | 9 +
> drivers/iio/dac/Makefile | 1 +
> drivers/iio/dac/ds4424.c | 733 +++++++++++++++++++++
> include/linux/iio/dac/ds4424.h | 29 +
> 5 files changed, 813 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iio/dac/ds4424.txt
> create mode 100644 drivers/iio/dac/ds4424.c
> create mode 100644 include/linux/iio/dac/ds4424.h
>
> diff --git a/Documentation/devicetree/bindings/iio/dac/ds4424.txt b/Documentation/devicetree/bindings/iio/dac/ds4424.txt
> new file mode 100644
> index 000000000000..03c1b575a6db
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/dac/ds4424.txt
> @@ -0,0 +1,41 @@
> +Maxim Integrated DS4422/DS4424 DAC device driver
> +
> +Required properties:
> + - compatible: Must be "maxim,ds4422" or "maxim,ds4424"
> + - reg: Should contain the DAC I2C address
> + - min_rfs, max_rfs: In order to get the correct processed data values,
> + these resistor values should be changed to the correct values
> + that match the user's system resistor values for RFS0 to RFS1.
> + Resistance values for rfs_resistor are listed in 100 Ohm units;
> + ie, 800 is 80K. Acceptable RFS values are 40K to 160K.
> + - ifs_scale: 61000*100 = 6100000 = 100,000,000 * .976/16
> + - max_picoamp: Should contain DAC maximum pico amper value.
ampere
> + - rfs_resistor: Should contain reference resistor
> + - iio map: Should contain IIO Map info
> +
> +Optional properties:
> + - vcc-supply: Power supply us optional. If not defined, driver will ignore it.
_is_ optional
> +
> +Example:
> + ds4224@10 {
> + compatible = "maxim,ds4424";
> + reg = <0x10>; /* When A0, A1 pins are ground */
> + vcc-supply = "dac_vcc_3v3";
> + max-picoamp = <200000000>; /* 200uA */
> + ifs-scale = <61000>;
> + /* In order to get the correct processed data values,
this duplicates the text above, maybe drop it here?
> + these resistor values should be changed to the correct values that match the
> + user's system resistor values for RFS0 to RFS1.
> + Resistance values for rfs_resistor are listed in 100 Ohm units;
> + ie, 800 is 80K. Acceptable RFS values are 40K to 160K.
> + */
> + min-rfs = <400>;
> + max-rfs = <1600>;
> + rfs-resistors = <400 800 1000 1600>;
> + dac-iio-map =
> + /* consumer_dev_name, consumer_channel, adc_channel_label */
> + "ds4424_dac-consumer-dev_name-1", "ds4424_dac1", "OUT1",
> + "ds4424_dac-consumer-dev_name-2", "ds4424_dac2", "OUT2",
> + "ds4424_dac-consumer-dev_name-3", "ds4424_dac3", "OUT3",
> + "ds4424_dac-consumer-dev_name-4", "ds4424_dac4", "OUT4";
> + };
> diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
> index df5abc46cd3f..6f569c0ac88a 100644
> --- a/drivers/iio/dac/Kconfig
> +++ b/drivers/iio/dac/Kconfig
> @@ -309,4 +309,13 @@ config VF610_DAC
> This driver can also be built as a module. If so, the module will
> be called vf610_dac.
>
> +config DAC_DS4424
maybe simply DS4424
> + tristate "Maxim Integrated DS4422/DS4424 DAC driver"
> + depends on I2C
> + help
> + If you say yes here you get support for Maxim chip DS4422, DS4424.
chips
> +
> + This driver can also be built as a module. If so, the module
> + will be called DAC_DS4424.
module name will be lowercase, ds4424
> +
> endmenu
> diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
> index 603587cc2f07..fa77510a5538 100644
> --- a/drivers/iio/dac/Makefile
> +++ b/drivers/iio/dac/Makefile
> @@ -33,3 +33,4 @@ 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
> +obj-$(CONFIG_DAC_DS4424) += ds4424.o
alphabetic order please, maybe change to CONFIG_DS4424_DAC
> diff --git a/drivers/iio/dac/ds4424.c b/drivers/iio/dac/ds4424.c
> new file mode 100644
> index 000000000000..d13590a00c79
> --- /dev/null
> +++ b/drivers/iio/dac/ds4424.c
> @@ -0,0 +1,733 @@
> +/*
> + * Maxim Integrated
> + * 7-bit, Multi-Channel Sink/Source Current DAC Driver
> + * Copyright (C) 2017 Maxim Integrated
> + *
> + * 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.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/i2c.h>
> +#include <linux/platform_device.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/err.h>
> +#include <linux/delay.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/driver.h>
> +#include <linux/iio/machine.h>
> +#include <linux/iio/dac/ds4424.h>
> +
> +#define DS4424_DAC_ADDR(chan) ((chan) + 0xf8)
> +#define SOURCE_I 1
prefix with DS4424_ or ds4424_
> +#define SINK_I 0
> +
> +#define PWR_ON true
> +#define PWR_OFF false
> +
> +#define DS4424_CHANNEL(chan) { \
> + .type = IIO_CURRENT, \
> + .indexed = 1, \
> + .output = 1, \
> + .channel = chan, \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
> + BIT(IIO_CHAN_INFO_PROCESSED) | \
> + BIT(IIO_CHAN_INFO_SCALE),\
> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET), \
> + .address = DS4424_DAC_ADDR(chan), \
> + .scan_type = { \
> + .sign = 'u', \
> + .realbits = 8, \
> + .storagebits = 8, \
> + .shift = 0, \
.shift not strictly needed
> + }, \
> +}
> +
> +union raw_data {
> + struct {
> + u8 dx:7;
> + u8 source_bit:1; /* 1 is source, 0 is sink */
> + };
> + u8 bits;
> +};
> +
> +enum ds4424_device_ids {
> + ID_DS4422,
> + ID_DS4424,
> +};
> +
> +struct ds4424_data {
> + struct i2c_client *client;
> + struct mutex lock;
> + uint16_t raw[DS442X_MAX_DAC_CHANNELS];
avoid wildcards such as X if possible
> +#ifdef CONFIG_PM_SLEEP
> + uint16_t save[DS442X_MAX_DAC_CHANNELS];
> +#endif
> + uint32_t max_rfs;
> + uint32_t min_rfs;
> + uint32_t ifs_scale;
> + uint32_t max_picoamp;
> + uint32_t rfs_res[DS442X_MAX_DAC_CHANNELS];
> + struct iio_map dac_iio_map[DS442X_MAX_DAC_CHANNELS + 1];
maybe a comment why you have + 1?
> + struct regulator *vcc_reg;
> + const char *vcc_reg_name;
> + bool regulator_state;
> +};
> +
> +static const struct ds4424_pdata ds4424_pdata_default = {
> + /* .vcc_supply_name = "dac_vdd_3v3", */
drop comment
> + .min_rfs = 400,
> + .max_rfs = 1600,
> + .ifs_scale = 61000, /* 61000*100 = 6100000 = 100,000,000 * .976/16 */
> + .max_picoamp = 200000000,
> + .rfs_res = {400, 800, 1000, 1600},
> + .dac_iio_map = {
> + { .consumer_dev_name = "ds4424_dac-consumer-dev_name-1",
> + .consumer_channel = "ds4424_dac1",
> + .adc_channel_label = "OUT1"
> + },
> + {
> + .consumer_dev_name = "ds4424_dac-consumer-dev_name-2",
> + .consumer_channel = "ds4424_dac2",
> + .adc_channel_label = "OUT2"
> + },
> + {
> + .consumer_dev_name = "ds4424_dac-consumer-dev_name-3",
> + .consumer_channel = "ds4424_dac3",
> + .adc_channel_label = "OUT3"
> + },
> + {
> + .consumer_dev_name = "ds4424_dac-consumer-dev_name-4",
> + .consumer_channel = "ds4424_dac4",
> + .adc_channel_label = "OUT4"
> + },
> + {},
> + },
> +};
> +
> +static const struct iio_chan_spec ds4424_channels[] = {
> + DS4424_CHANNEL(0),
> + DS4424_CHANNEL(1),
> + DS4424_CHANNEL(2),
> + DS4424_CHANNEL(3)
> +};
> +
> +int ds4424_regulator_onoff(struct iio_dev *indio_dev, bool enable)
> +{
> + struct ds4424_data *data = iio_priv(indio_dev);
> + int ret = 0;
> +
> + if (data->vcc_reg == NULL)
> + return ret;
> +
> + if (data->regulator_state == PWR_OFF && enable == PWR_ON) {
> + ret = regulator_enable(data->vcc_reg);
> + if (ret) {
> + pr_err("%s - enable vcc_reg failed, ret=%d\n",
> + __func__, ret);
> + goto done;
> + }
> + } else if (data->regulator_state == PWR_ON && enable == PWR_OFF) {
> + ret = regulator_disable(data->vcc_reg);
> + if (ret) {
> + pr_err("%s - disable vcc_reg failed, ret=%d\n",
> + __func__, ret);
> + goto done;
> + }
> + }
> +
> + data->regulator_state = enable;
> +done:
> + return ret;
> +}
> +
> +static int ds4424_get_value(struct iio_dev *indio_dev,
> + int *val, int channel)
> +{
> + struct ds4424_data *data = iio_priv(indio_dev);
> + struct i2c_client *client = data->client;
> + u8 outbuf[1];
> + u8 inbuf[1];
> + int ret;
> +
> + if ((channel < 0) && (channel >= indio_dev->num_channels))
> + return -EINVAL;
> +
> + outbuf[0] = DS4424_DAC_ADDR(channel);
> + mutex_lock(&data->lock);
> + ret = i2c_master_send(client, outbuf, 1);
> + if (ret < 0) {
> + mutex_unlock(&data->lock);
> + return ret;
> + } else if (ret != 1) {
> + mutex_unlock(&data->lock);
> + return -EIO;
> + }
> +
> + ret = i2c_master_recv(client, inbuf, 1);
> + if (ret < 0) {
> + mutex_unlock(&data->lock);
> + return ret;
> + } else if (ret != 1) {
> + mutex_unlock(&data->lock);
> + return -EIO;
> + }
> +
> + mutex_unlock(&data->lock);
> +
> + *val = inbuf[0];
> + return 0;
> +}
> +
> +/*
> + * DS4432 DAC control register 8 bits
DS4422?
> + * [7] 0: to sink; 1: to source
> + * [6:0] steps to sink/source
> + * bit[7] looks like a sign bit, but the value of the register is
> + * not a complemental code considering the bit[6:0] is a absolute
> + * distance from the zero point.
> + */
> +
> +/*
> + * val is positive if sourcing
> + * val is negative if sinking
> + * val can be -127 to 127
> + */
> +static int ds4424_set_value(struct iio_dev *indio_dev,
> + int val, struct iio_chan_spec const *chan)
> +{
> + struct ds4424_data *data = iio_priv(indio_dev);
> + struct i2c_client *client = data->client;
> + u8 outbuf[2];
> + int ret;
> + int max_val = ((1 << chan->scan_type.realbits) - 1);
> +
> + if (val < 0 || val > max_val)
> + return -EINVAL;
> +
> + if ((chan->channel < 0)
parenthesis not strictly necessary
> + && (chan->channel >= indio_dev->num_channels))
> + return -EINVAL;
> +
> + outbuf[0] = DS4424_DAC_ADDR(chan->channel);
> + outbuf[1] = (val & 0xff);
parenthesis not needed
> +
> + mutex_lock(&data->lock);
> + ret = i2c_master_send(client, outbuf, ARRAY_SIZE(outbuf));
sizeof(outbuf)
> + mutex_unlock(&data->lock);
> +
> + if (ret < 0)
> + return ret;
> + else if (ret >= 0 && ret != ARRAY_SIZE(outbuf))
> + return -EIO;
> +
> + data->raw[chan->channel] = outbuf[1];
> + return 0;
> +}
> +
> +static int ds4424_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)
> +{
> + union raw_data raw;
> + int round_up, ret;
> + struct ds4424_data *data = iio_priv(indio_dev);
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + /* Raw is processed a little bit
> + * outputs positive values for sourcing
> + * and negative values for sinking
> + */
> + ret = ds4424_get_value(indio_dev, val, chan->channel);
> + if (ret < 0) {
> + pr_err("%s : ds4424_get_value returned %d\n",
> + __func__, ret);
> + return ret;
> + }
> + raw.bits = *val;
> + *val = raw.dx;
> + if (raw.source_bit == SINK_I)
> + *val = -*val;
> + return IIO_VAL_INT;
> +
> + case IIO_CHAN_INFO_PROCESSED:
> + /**
> + * To get the processed current using the 8-bit raw data:
> + * bit 7 is a 1 if sourcing current and it's a 0 if sinking
> + * current.
> + * The current full scale (Ifs) depends on the Rfs resistor
> + * value in ohms:
> + * Ifs = (0.976/Rfs)*(127/16)
> + * Then the current sourced or sinked can be determined as
> + * follows:
> + * I = Ifs * (Dx/127)
> + * where Dx is the value of the seven bits 6 to 0.
> + */
> + if (data->rfs_res[chan->channel] < data->min_rfs ||
> + data->rfs_res[chan->channel] > data->max_rfs) {
> + pr_err("%s : rfs_res out of range. rfs_res[%d]: %d\n",
> + __func__,
> + chan->channel,
> + data->rfs_res[chan->channel]);
> + return -EINVAL;
> + }
> +
> + ret = ds4424_get_value(indio_dev, val, chan->channel);
> + if (ret < 0) {
> + pr_err("%s : ds4424_get_value returned %d\n",
> + __func__, ret);
> + return ret;
> + }
> + raw.bits = *val;
> + *val = data->ifs_scale * raw.dx * 100;
> + round_up = data->rfs_res[chan->channel] / 2;
> + *val = (*val + round_up) / data->rfs_res[chan->channel];
> +
> + if (raw.source_bit == SINK_I)
> + *val = -*val;
> + *val = *val * 100; /* picoAmps */
> + return IIO_VAL_INT;
> +
> + case IIO_CHAN_INFO_SCALE:
> + round_up = data->rfs_res[chan->channel] / 2;
> + /* picoAmps */
> + *val = (data->ifs_scale * 10000 + round_up) /
> + data->rfs_res[chan->channel];
> + return IIO_VAL_INT;
> +
> + case IIO_CHAN_INFO_OFFSET:
> + *val = 0;
> + return IIO_VAL_INT;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +/**
> + * val is positive if sourcing
> + * val is negative if sinking
> + */
> +static int ds4424_write_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int val, int val2, long mask)
> +{
> + union raw_data raw;
> + struct ds4424_data *data = iio_priv(indio_dev);
> + int val0, max_val, min_val, tmp_scale;
> +
> + if (val2 != 0)
> + return -EINVAL;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> +
> + max_val = ((1 << chan->scan_type.realbits)/2) - 1;
spaces before and after /
> + min_val = -max_val;
> + if ((val > max_val) || (val < min_val))
parenthesis not needed
> + return -EINVAL;
> +
> + if (val > 0) {
> + raw.source_bit = SOURCE_I;
> + raw.dx = val;
> + } else {
> + raw.source_bit = SINK_I;
> + raw.dx = -val;
> + }
> +
> + return ds4424_set_value(indio_dev, raw.bits, chan);
> +
> + case IIO_CHAN_INFO_PROCESSED: /* val input is picoAmps */
> + /* val can be 0 to 200,000,000 (200 picoAmps) */
> + val0 = val;
> + raw.source_bit = SOURCE_I;
> + if (val < 0) {
> + raw.source_bit = SINK_I;
> + val = -val;
> + }
> + if (val > data->max_picoamp) {
> + pr_err("%s : Requested current %d ", __func__, val);
> + pr_err("exceeds %d picoAmps\n", data->max_picoamp);
> + return -EINVAL;
> + }
> + if (data->rfs_res[chan->channel] < data->min_rfs ||
> + data->rfs_res[chan->channel] > data->max_rfs) {
> + pr_info("%s : Resistor values out of range\n",
> + __func__);
> + return -EINVAL;
> + }
> + val = val / 1000;
> + tmp_scale = data->ifs_scale / 10; /* preserve resolution */
> + val = (val * data->rfs_res[chan->channel]) /
> + tmp_scale;
> + val = (val + 50) / 100;
> + val2 = ((1 << chan->scan_type.realbits) / 2) - 1;
> + if (val > val2) {
> + pr_info("%s : Requested current %d %d",
> + __func__, val0, val);
> + pr_info("exceeds maximum. DAC set to maximum %d\n",
> + val2);
> + val = val2;
> + }
> + raw.dx = val;
> + return ds4424_set_value(indio_dev, raw.bits, chan);
> +
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int ds4424_verify_chip(struct iio_dev *indio_dev)
> +{
> + int ret = 0, val;
> + int i;
> +
> + usleep_range(1000, 1200);
> + for (i = 0; i < indio_dev->num_channels; i++) {
> + ret = ds4424_get_value(indio_dev, &val, i);
> + if (ret < 0) {
> + pr_err("%s : read %d, should be 0\n", __func__, ret);
> + break;
> + }
> + }
> + return ret;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int ds4424_suspend(struct device *dev)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
> + struct ds4424_data *data = iio_priv(indio_dev);
> + int ret = 0;
> + u32 i;
> +
> + for (i = 0; i < indio_dev->num_channels; i++) {
> + data->save[i] = data->raw[i];
> + ret = ds4424_set_value(indio_dev, 0,
> + &(indio_dev->channels[i]));
&() parenthesis not needed, here and below
> + if (ret < 0)
> + return ret;
> + }
> + return ret;
> +}
> +
> +static int ds4424_resume(struct device *dev)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
> + struct ds4424_data *data = iio_priv(indio_dev);
> + int ret = 0;
> + u32 i;
> +
> + for (i = 0; i < indio_dev->num_channels; i++) {
> + ret = ds4424_set_value(indio_dev, data->save[i],
> + &(indio_dev->channels[i]));
> + if (ret < 0)
> + return ret;
> + }
> + return ret;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(ds4424_pm_ops, ds4424_suspend, ds4424_resume);
> +#define DS4424_PM_OPS (&ds4424_pm_ops)
> +#else
> +#define DS4424_PM_OPS NULL
> +#endif /* CONFIG_PM_SLEEP */
> +
> +static const struct iio_info ds4424_info = {
> + .read_raw = ds4424_read_raw,
> + .write_raw = ds4424_write_raw,
> + .driver_module = THIS_MODULE,
> +};
> +
> +#ifdef CONFIG_OF
> +static int ds4424_parse_dt(struct iio_dev *indio_dev)
> +{
> + int ret;
> + int len;
> + int num_ch;
> + int i;
> + int count;
> + struct property *prop;
> + struct ds4424_data *data = iio_priv(indio_dev);
> + struct device_node *node = indio_dev->dev.parent->of_node;
> +
> + if (!node) {
> + pr_info("%s:%d ds4424 dts not found\n", __func__, __LINE__);
> + return -ENODEV;
> + }
> +
> + prop = of_find_property(node, "rfs-resistors", &len);
> + if (!prop) {
> + pr_err("Invalid rfs-resistor in dt. len: %d\n", len);
> + return -EINVAL;
> + }
> +
> + if (len != (DS442X_MAX_DAC_CHANNELS * sizeof(uint32_t))) {
> + pr_err("Invalid rfs-resistor length in dt. len: %d\n", len);
> + return -EINVAL;
> + }
> +
> + ret = of_property_read_u32_array(node, "rfs-resistors",
> + data->rfs_res, DS442X_MAX_DAC_CHANNELS);
> + if (ret < 0) {
> + pr_err("Reading rfs-resistors from dt failed. ret: %d\n", ret);
> + return ret;
> + }
> +
> + pr_info("ds4424 rfs-resistors: %d, %d, %d, %d\n",
> + data->rfs_res[0], data->rfs_res[1],
> + data->rfs_res[2], data->rfs_res[3]);
> +
> + ret = of_property_read_u32(node, "max-rfs",
> + &data->max_rfs);
> + if (ret < 0) {
> + pr_err("Reading max-rfs from dt failed. ret: %d\n", ret);
> + return ret;
> + }
> +
> + ret = of_property_read_u32(node, "min-rfs",
> + (u32 *)&data->min_rfs);
> + if (ret < 0) {
> + pr_err("Reading min-rfs from dt failed. ret: %d\n", ret);
> + return ret;
> + }
> +
> + pr_info("ds4424 max-rfs: %d, min-rfs: %d\n",
> + data->max_rfs, data->min_rfs);
> +
> + ret = of_property_read_u32(node, "max-picoamp",
> + (u32 *)&data->max_picoamp);
> + if (ret < 0) {
> + pr_err("Reading max-picoamp from dt failed. ret: %d\n", ret);
> + return ret;
> + }
> +
> + ret = of_property_read_u32(node, "ifs-scale",
> + (u32 *)&data->ifs_scale);
> + if (ret < 0) {
> + pr_err("Reading ifs-scale from dt failed. ret: %d\n", ret);
> + return ret;
> + }
> +
> + pr_info("ds4424 max-picoamp: %d, ifs-scale: %d\n",
> + data->max_picoamp, data->ifs_scale);
> +
> + count = of_property_count_strings(node, "dac-iio-map");
> + if (count < 0) {
> + pr_info("dac-iio-map not found in dts\n");
> + return count;
> + }
> +
> + ret = of_property_read_string(node, "vcc-supply", &data->vcc_reg_name);
> + if (ret < 0) {
> + pr_info("DAC vcc-supply is not available in dts\n");
dt vs dts, here and below; maybe DT?
> + data->vcc_reg_name = NULL;
> + }
> +
> + if (count != DS4424_MAX_DAC_CHANNELS * 3 &&
> + count != DS4424_MAX_DAC_CHANNELS * 3) {
> + pr_info("Incorrect dac-iio-map in dts. count: %d\n", count);
> + return -EINVAL;
> + }
> +
> + num_ch = count / 3;
> + for (i = 0; i < num_ch; i++) {
> + ret = of_property_read_string_index(node,
> + "dac-iio-map", i * 3,
> + &data->dac_iio_map[i].consumer_dev_name);
> + if (ret < 0) {
> + pr_info("%s:%d\n", __func__, __LINE__);
> + return ret;
> + }
> +
> + ret = of_property_read_string_index(node, "dac-iio-map",
> + i * 3 + 1,
> + &data->dac_iio_map[i].consumer_channel);
> + if (ret < 0) {
> + pr_info("%s:%d\n", __func__, __LINE__);
> + return ret;
> + }
> +
> + ret = of_property_read_string_index(node, "dac-iio-map",
> + i * 3 + 2,
> + &data->dac_iio_map[i].adc_channel_label);
> + if (ret < 0) {
> + pr_info("%s:%d\n", __func__, __LINE__);
> + return ret;
> + }
> +
> + pr_info("ds4424 iio-map[%d]: %s, %s, %s\n", i,
> + data->dac_iio_map[i].consumer_dev_name,
> + data->dac_iio_map[i].consumer_channel,
> + data->dac_iio_map[i].adc_channel_label);
> + }
> +
> + return 0;
> +}
> +#else
> +static int ds4424_parse_dt(struct iio_dev *indio_dev)
> +{
> + return -ENODEV;
> +}
> +#endif
> +
> +static int ds4424_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + const struct ds4424_pdata *pdata;
> + struct ds4424_data *data;
> + struct iio_dev *indio_dev;
> + int ret;
> +
> + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
> + dev_err(&client->dev, "I2C is not supported\n");
> + return -ENODEV;
> + }
> +
> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> + if (!indio_dev) {
> + pr_err("%s:%d\n", __func__, __LINE__);
> + return -ENOMEM;
> + }
> +
> + data = iio_priv(indio_dev);
> + memset(data, 0, sizeof(*data));
> + i2c_set_clientdata(client, indio_dev);
> + data->client = client;
> + indio_dev->name = id->name;
> + indio_dev->dev.parent = &client->dev;
> +
> + ret = ds4424_verify_chip(indio_dev);
> + if (ret < 0) {
> + dev_err(&client->dev, "%s failed. ret:%d\n", __func__, ret);
> + return -ENXIO;
> + }
> +
> + if (client->dev.of_node) {
> + ret = ds4424_parse_dt(indio_dev);
> + if (ret < 0) {
> + dev_err(&client->dev,
> + "%s - of_node error\n", __func__);
> + ret = -EINVAL;
> + }
> + } else {
> + pdata = client->dev.platform_data;
extra spaces after =
> + if (!pdata) {
> + dev_err(&client->dev,
> + "dts/platform data not found.\n");
> + /* Use default driver settings */
> + pdata = &ds4424_pdata_default;
> + }
> +
> + pdata = client->dev.platform_data;
> + data->min_rfs = pdata->min_rfs;
> + data->max_rfs = pdata->max_rfs;
> + data->ifs_scale = pdata->ifs_scale;
> + data->max_picoamp = pdata->max_picoamp;
> + data->vcc_reg_name = pdata->vcc_supply_name;
> + memcpy(data->rfs_res, pdata->rfs_res,
> + sizeof(uint32_t) * DS442X_MAX_DAC_CHANNELS);
> + memcpy(data->dac_iio_map, pdata->dac_iio_map,
> + sizeof(struct iio_map) * DS442X_MAX_DAC_CHANNELS);
> + }
> +
> + if (data->vcc_reg_name) {
> + data->vcc_reg = devm_regulator_get(&client->dev,
> + data->vcc_reg_name);
> + if (IS_ERR(data->vcc_reg)) {
> + ret = PTR_ERR(data->vcc_reg);
> + dev_err(&client->dev,
> + "Failed to get vcc_reg regulator: %d\n", ret);
> + return ret;
> + }
> + }
> +
> + mutex_init(&data->lock);
> + ret = ds4424_regulator_onoff(indio_dev, PWR_ON);
> + if (ret < 0) {
> + pr_err("Unable to turn on the regulator. %s:%d, ret: %d\n",
> + __func__, __LINE__, ret);
> + return ret;
> + }
> +
> + switch (id->driver_data) {
> + case ID_DS4422:
> + indio_dev->num_channels = DS4422_MAX_DAC_CHANNELS;
> + break;
> + case ID_DS4424:
> + indio_dev->num_channels = DS4424_MAX_DAC_CHANNELS;
> + break;
> + default:
> + indio_dev->num_channels = DS4424_MAX_DAC_CHANNELS;
> + break;
> + }
> +
> + indio_dev->channels = ds4424_channels;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->info = &ds4424_info;
> +
> + ret = iio_map_array_register(indio_dev, data->dac_iio_map);
> + if (ret < 0)
> + goto err_iio_device_0;
> +
> + ret = iio_device_register(indio_dev);
> + if (ret < 0) {
> + pr_err("iio_device_register failed . %s:%d, ret: %d\n",
delete space after 'failed'
> + __func__, __LINE__, ret);
> + goto err_iio_device_1;
> + }
> +
> + return ret;
> +
> +err_iio_device_0:
> + ds4424_regulator_onoff(indio_dev, PWR_OFF);
> +err_iio_device_1:
> + iio_map_array_unregister(indio_dev);
> + return ret;
> +}
> +
> +static int ds4424_remove(struct i2c_client *client)
> +{
> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +
> + iio_device_unregister(indio_dev);
> + iio_map_array_unregister(indio_dev);
> + ds4424_regulator_onoff(indio_dev, PWR_OFF);
> + return 0;
> +}
> +
> +static const struct i2c_device_id ds4424_id[] = {
> + { "ds4422", ID_DS4422 },
> + { "ds4424", ID_DS4424 },
> + { }
> +};
> +MODULE_DEVICE_TABLE(i2c, ds4424_id);
> +
> +static const struct of_device_id ds4424_of_match[] = {
> + { .compatible = "maxim,ds4422" },
> + { .compatible = "maxim,ds4424" },
> + { }
> +};
> +
> +MODULE_DEVICE_TABLE(of, ds4424_of_match);
> +
> +static struct i2c_driver ds4424_driver = {
> + .driver = {
> + .name = "ds4424",
> + .pm = DS4424_PM_OPS,
> + },
> + .probe = ds4424_probe,
> + .remove = ds4424_remove,
> + .id_table = ds4424_id,
> +};
> +module_i2c_driver(ds4424_driver);
> +
> +MODULE_DESCRIPTION("Maxim DS4424 DAC Driver");
> +MODULE_AUTHOR("Ismail H. Kose <ismail.kose@maximintegrated.com>");
> +MODULE_AUTHOR("Vishal Sood <vishal.sood@maximintegrated.com>");
> +MODULE_AUTHOR("David Jung <david.jung@maximintegrated.com>");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/iio/dac/ds4424.h b/include/linux/iio/dac/ds4424.h
> new file mode 100644
> index 000000000000..09ff3d61797d
> --- /dev/null
> +++ b/include/linux/iio/dac/ds4424.h
> @@ -0,0 +1,29 @@
> +/*
> + * Maxim Integrated
> + * 7-bit, Multi-Channel Sink/Source Current DAC Driver
> + * Copyright (C) 2017 Maxim Integrated
> + *
> + * 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.
> + */
> +
> +#ifndef IIO_DAC_DS4424_H_
> +#define IIO_DAC_DS4424_H_
> +#include <linux/iio/iio.h>
> +#include <linux/iio/machine.h>
> +
> +#define DS4422_MAX_DAC_CHANNELS 2
> +#define DS4424_MAX_DAC_CHANNELS 4
> +#define DS442X_MAX_DAC_CHANNELS DS4424_MAX_DAC_CHANNELS
> +
> +struct ds4424_pdata {
> + const char *vcc_supply_name;
> + uint32_t max_rfs;
> + uint32_t min_rfs;
> + uint32_t ifs_scale;
> + uint32_t max_picoamp;
> + uint32_t rfs_res[DS442X_MAX_DAC_CHANNELS];
> + struct iio_map dac_iio_map[DS442X_MAX_DAC_CHANNELS + 1];
> +};
> +#endif /* IIO_DAC_DS4424_H_ */
>
--
Peter Meerwald-Stadler
Mobile: +43 664 24 44 418
WARNING: multiple messages have this Message-ID (diff)
From: Peter Meerwald-Stadler <pmeerw-jW+XmwGofnusTnJN9+BGXg@public.gmane.org>
To: Ismail Kose
<Ismail.Kose-zxKO94PEStzToO697jQleEEOCMrvLtNR@public.gmane.org>
Cc: jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
knaack.h-Mmb7MZpHnFY@public.gmane.org,
lars-Qo5EllUWu/uELgA04lAiVw@public.gmane.org,
robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
mark.rutland-5wv7dgnIgG8@public.gmane.org,
vilhelm.gray-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org,
jeff.dagenais-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
fabrice.gasnier-qxv4g6HH51o@public.gmane.org,
gwenhael.goavec-merou-W7CSdorvuhNZroRs9YW3xA@public.gmane.org,
peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org,
maxime.roussinbelanger-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
ihkose-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH] iio: dac: DS4424: add Maxim DS4422/DS4424 DAC driver support
Date: Sun, 25 Jun 2017 23:33:57 +0200 (CEST) [thread overview]
Message-ID: <alpine.DEB.2.20.1706241114510.18383@vps.pmeerw.net> (raw)
In-Reply-To: <20170623230404.2283-1-Ismail.Kose-zxKO94PEStzToO697jQleEEOCMrvLtNR@public.gmane.org>
> Add iio driver for DS4422/DS4424 chips that support two/four channel 7-bit
> Sink/Source Current DAC.
minor comments below, on top of Jonathan's
> The driver supports device tree and platfrom files for the configurations.
platform
> Datasheet publicly available at:
> https://datasheets.maximintegrated.com/en/ds/DS4422-DS4424.pdf
>
> Signed-off-by: Ismail Kose <Ismail.Kose-zxKO94PEStzToO697jQleEEOCMrvLtNR@public.gmane.org>
> ---
> .../devicetree/bindings/iio/dac/ds4424.txt | 41 ++
> drivers/iio/dac/Kconfig | 9 +
> drivers/iio/dac/Makefile | 1 +
> drivers/iio/dac/ds4424.c | 733 +++++++++++++++++++++
> include/linux/iio/dac/ds4424.h | 29 +
> 5 files changed, 813 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iio/dac/ds4424.txt
> create mode 100644 drivers/iio/dac/ds4424.c
> create mode 100644 include/linux/iio/dac/ds4424.h
>
> diff --git a/Documentation/devicetree/bindings/iio/dac/ds4424.txt b/Documentation/devicetree/bindings/iio/dac/ds4424.txt
> new file mode 100644
> index 000000000000..03c1b575a6db
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/dac/ds4424.txt
> @@ -0,0 +1,41 @@
> +Maxim Integrated DS4422/DS4424 DAC device driver
> +
> +Required properties:
> + - compatible: Must be "maxim,ds4422" or "maxim,ds4424"
> + - reg: Should contain the DAC I2C address
> + - min_rfs, max_rfs: In order to get the correct processed data values,
> + these resistor values should be changed to the correct values
> + that match the user's system resistor values for RFS0 to RFS1.
> + Resistance values for rfs_resistor are listed in 100 Ohm units;
> + ie, 800 is 80K. Acceptable RFS values are 40K to 160K.
> + - ifs_scale: 61000*100 = 6100000 = 100,000,000 * .976/16
> + - max_picoamp: Should contain DAC maximum pico amper value.
ampere
> + - rfs_resistor: Should contain reference resistor
> + - iio map: Should contain IIO Map info
> +
> +Optional properties:
> + - vcc-supply: Power supply us optional. If not defined, driver will ignore it.
_is_ optional
> +
> +Example:
> + ds4224@10 {
> + compatible = "maxim,ds4424";
> + reg = <0x10>; /* When A0, A1 pins are ground */
> + vcc-supply = "dac_vcc_3v3";
> + max-picoamp = <200000000>; /* 200uA */
> + ifs-scale = <61000>;
> + /* In order to get the correct processed data values,
this duplicates the text above, maybe drop it here?
> + these resistor values should be changed to the correct values that match the
> + user's system resistor values for RFS0 to RFS1.
> + Resistance values for rfs_resistor are listed in 100 Ohm units;
> + ie, 800 is 80K. Acceptable RFS values are 40K to 160K.
> + */
> + min-rfs = <400>;
> + max-rfs = <1600>;
> + rfs-resistors = <400 800 1000 1600>;
> + dac-iio-map =
> + /* consumer_dev_name, consumer_channel, adc_channel_label */
> + "ds4424_dac-consumer-dev_name-1", "ds4424_dac1", "OUT1",
> + "ds4424_dac-consumer-dev_name-2", "ds4424_dac2", "OUT2",
> + "ds4424_dac-consumer-dev_name-3", "ds4424_dac3", "OUT3",
> + "ds4424_dac-consumer-dev_name-4", "ds4424_dac4", "OUT4";
> + };
> diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
> index df5abc46cd3f..6f569c0ac88a 100644
> --- a/drivers/iio/dac/Kconfig
> +++ b/drivers/iio/dac/Kconfig
> @@ -309,4 +309,13 @@ config VF610_DAC
> This driver can also be built as a module. If so, the module will
> be called vf610_dac.
>
> +config DAC_DS4424
maybe simply DS4424
> + tristate "Maxim Integrated DS4422/DS4424 DAC driver"
> + depends on I2C
> + help
> + If you say yes here you get support for Maxim chip DS4422, DS4424.
chips
> +
> + This driver can also be built as a module. If so, the module
> + will be called DAC_DS4424.
module name will be lowercase, ds4424
> +
> endmenu
> diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
> index 603587cc2f07..fa77510a5538 100644
> --- a/drivers/iio/dac/Makefile
> +++ b/drivers/iio/dac/Makefile
> @@ -33,3 +33,4 @@ obj-$(CONFIG_MCP4922) += mcp4922.o
> obj-$(CONFIG_STM32_DAC_CORE) += stm32-dac-core.o
> obj-$(CONFIG_STM32_DAC) += stm32-dac.o
> obj-$(CONFIG_VF610_DAC) += vf610_dac.o
> +obj-$(CONFIG_DAC_DS4424) += ds4424.o
alphabetic order please, maybe change to CONFIG_DS4424_DAC
> diff --git a/drivers/iio/dac/ds4424.c b/drivers/iio/dac/ds4424.c
> new file mode 100644
> index 000000000000..d13590a00c79
> --- /dev/null
> +++ b/drivers/iio/dac/ds4424.c
> @@ -0,0 +1,733 @@
> +/*
> + * Maxim Integrated
> + * 7-bit, Multi-Channel Sink/Source Current DAC Driver
> + * Copyright (C) 2017 Maxim Integrated
> + *
> + * 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.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/i2c.h>
> +#include <linux/platform_device.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/err.h>
> +#include <linux/delay.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/driver.h>
> +#include <linux/iio/machine.h>
> +#include <linux/iio/dac/ds4424.h>
> +
> +#define DS4424_DAC_ADDR(chan) ((chan) + 0xf8)
> +#define SOURCE_I 1
prefix with DS4424_ or ds4424_
> +#define SINK_I 0
> +
> +#define PWR_ON true
> +#define PWR_OFF false
> +
> +#define DS4424_CHANNEL(chan) { \
> + .type = IIO_CURRENT, \
> + .indexed = 1, \
> + .output = 1, \
> + .channel = chan, \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
> + BIT(IIO_CHAN_INFO_PROCESSED) | \
> + BIT(IIO_CHAN_INFO_SCALE),\
> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET), \
> + .address = DS4424_DAC_ADDR(chan), \
> + .scan_type = { \
> + .sign = 'u', \
> + .realbits = 8, \
> + .storagebits = 8, \
> + .shift = 0, \
.shift not strictly needed
> + }, \
> +}
> +
> +union raw_data {
> + struct {
> + u8 dx:7;
> + u8 source_bit:1; /* 1 is source, 0 is sink */
> + };
> + u8 bits;
> +};
> +
> +enum ds4424_device_ids {
> + ID_DS4422,
> + ID_DS4424,
> +};
> +
> +struct ds4424_data {
> + struct i2c_client *client;
> + struct mutex lock;
> + uint16_t raw[DS442X_MAX_DAC_CHANNELS];
avoid wildcards such as X if possible
> +#ifdef CONFIG_PM_SLEEP
> + uint16_t save[DS442X_MAX_DAC_CHANNELS];
> +#endif
> + uint32_t max_rfs;
> + uint32_t min_rfs;
> + uint32_t ifs_scale;
> + uint32_t max_picoamp;
> + uint32_t rfs_res[DS442X_MAX_DAC_CHANNELS];
> + struct iio_map dac_iio_map[DS442X_MAX_DAC_CHANNELS + 1];
maybe a comment why you have + 1?
> + struct regulator *vcc_reg;
> + const char *vcc_reg_name;
> + bool regulator_state;
> +};
> +
> +static const struct ds4424_pdata ds4424_pdata_default = {
> + /* .vcc_supply_name = "dac_vdd_3v3", */
drop comment
> + .min_rfs = 400,
> + .max_rfs = 1600,
> + .ifs_scale = 61000, /* 61000*100 = 6100000 = 100,000,000 * .976/16 */
> + .max_picoamp = 200000000,
> + .rfs_res = {400, 800, 1000, 1600},
> + .dac_iio_map = {
> + { .consumer_dev_name = "ds4424_dac-consumer-dev_name-1",
> + .consumer_channel = "ds4424_dac1",
> + .adc_channel_label = "OUT1"
> + },
> + {
> + .consumer_dev_name = "ds4424_dac-consumer-dev_name-2",
> + .consumer_channel = "ds4424_dac2",
> + .adc_channel_label = "OUT2"
> + },
> + {
> + .consumer_dev_name = "ds4424_dac-consumer-dev_name-3",
> + .consumer_channel = "ds4424_dac3",
> + .adc_channel_label = "OUT3"
> + },
> + {
> + .consumer_dev_name = "ds4424_dac-consumer-dev_name-4",
> + .consumer_channel = "ds4424_dac4",
> + .adc_channel_label = "OUT4"
> + },
> + {},
> + },
> +};
> +
> +static const struct iio_chan_spec ds4424_channels[] = {
> + DS4424_CHANNEL(0),
> + DS4424_CHANNEL(1),
> + DS4424_CHANNEL(2),
> + DS4424_CHANNEL(3)
> +};
> +
> +int ds4424_regulator_onoff(struct iio_dev *indio_dev, bool enable)
> +{
> + struct ds4424_data *data = iio_priv(indio_dev);
> + int ret = 0;
> +
> + if (data->vcc_reg == NULL)
> + return ret;
> +
> + if (data->regulator_state == PWR_OFF && enable == PWR_ON) {
> + ret = regulator_enable(data->vcc_reg);
> + if (ret) {
> + pr_err("%s - enable vcc_reg failed, ret=%d\n",
> + __func__, ret);
> + goto done;
> + }
> + } else if (data->regulator_state == PWR_ON && enable == PWR_OFF) {
> + ret = regulator_disable(data->vcc_reg);
> + if (ret) {
> + pr_err("%s - disable vcc_reg failed, ret=%d\n",
> + __func__, ret);
> + goto done;
> + }
> + }
> +
> + data->regulator_state = enable;
> +done:
> + return ret;
> +}
> +
> +static int ds4424_get_value(struct iio_dev *indio_dev,
> + int *val, int channel)
> +{
> + struct ds4424_data *data = iio_priv(indio_dev);
> + struct i2c_client *client = data->client;
> + u8 outbuf[1];
> + u8 inbuf[1];
> + int ret;
> +
> + if ((channel < 0) && (channel >= indio_dev->num_channels))
> + return -EINVAL;
> +
> + outbuf[0] = DS4424_DAC_ADDR(channel);
> + mutex_lock(&data->lock);
> + ret = i2c_master_send(client, outbuf, 1);
> + if (ret < 0) {
> + mutex_unlock(&data->lock);
> + return ret;
> + } else if (ret != 1) {
> + mutex_unlock(&data->lock);
> + return -EIO;
> + }
> +
> + ret = i2c_master_recv(client, inbuf, 1);
> + if (ret < 0) {
> + mutex_unlock(&data->lock);
> + return ret;
> + } else if (ret != 1) {
> + mutex_unlock(&data->lock);
> + return -EIO;
> + }
> +
> + mutex_unlock(&data->lock);
> +
> + *val = inbuf[0];
> + return 0;
> +}
> +
> +/*
> + * DS4432 DAC control register 8 bits
DS4422?
> + * [7] 0: to sink; 1: to source
> + * [6:0] steps to sink/source
> + * bit[7] looks like a sign bit, but the value of the register is
> + * not a complemental code considering the bit[6:0] is a absolute
> + * distance from the zero point.
> + */
> +
> +/*
> + * val is positive if sourcing
> + * val is negative if sinking
> + * val can be -127 to 127
> + */
> +static int ds4424_set_value(struct iio_dev *indio_dev,
> + int val, struct iio_chan_spec const *chan)
> +{
> + struct ds4424_data *data = iio_priv(indio_dev);
> + struct i2c_client *client = data->client;
> + u8 outbuf[2];
> + int ret;
> + int max_val = ((1 << chan->scan_type.realbits) - 1);
> +
> + if (val < 0 || val > max_val)
> + return -EINVAL;
> +
> + if ((chan->channel < 0)
parenthesis not strictly necessary
> + && (chan->channel >= indio_dev->num_channels))
> + return -EINVAL;
> +
> + outbuf[0] = DS4424_DAC_ADDR(chan->channel);
> + outbuf[1] = (val & 0xff);
parenthesis not needed
> +
> + mutex_lock(&data->lock);
> + ret = i2c_master_send(client, outbuf, ARRAY_SIZE(outbuf));
sizeof(outbuf)
> + mutex_unlock(&data->lock);
> +
> + if (ret < 0)
> + return ret;
> + else if (ret >= 0 && ret != ARRAY_SIZE(outbuf))
> + return -EIO;
> +
> + data->raw[chan->channel] = outbuf[1];
> + return 0;
> +}
> +
> +static int ds4424_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)
> +{
> + union raw_data raw;
> + int round_up, ret;
> + struct ds4424_data *data = iio_priv(indio_dev);
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + /* Raw is processed a little bit
> + * outputs positive values for sourcing
> + * and negative values for sinking
> + */
> + ret = ds4424_get_value(indio_dev, val, chan->channel);
> + if (ret < 0) {
> + pr_err("%s : ds4424_get_value returned %d\n",
> + __func__, ret);
> + return ret;
> + }
> + raw.bits = *val;
> + *val = raw.dx;
> + if (raw.source_bit == SINK_I)
> + *val = -*val;
> + return IIO_VAL_INT;
> +
> + case IIO_CHAN_INFO_PROCESSED:
> + /**
> + * To get the processed current using the 8-bit raw data:
> + * bit 7 is a 1 if sourcing current and it's a 0 if sinking
> + * current.
> + * The current full scale (Ifs) depends on the Rfs resistor
> + * value in ohms:
> + * Ifs = (0.976/Rfs)*(127/16)
> + * Then the current sourced or sinked can be determined as
> + * follows:
> + * I = Ifs * (Dx/127)
> + * where Dx is the value of the seven bits 6 to 0.
> + */
> + if (data->rfs_res[chan->channel] < data->min_rfs ||
> + data->rfs_res[chan->channel] > data->max_rfs) {
> + pr_err("%s : rfs_res out of range. rfs_res[%d]: %d\n",
> + __func__,
> + chan->channel,
> + data->rfs_res[chan->channel]);
> + return -EINVAL;
> + }
> +
> + ret = ds4424_get_value(indio_dev, val, chan->channel);
> + if (ret < 0) {
> + pr_err("%s : ds4424_get_value returned %d\n",
> + __func__, ret);
> + return ret;
> + }
> + raw.bits = *val;
> + *val = data->ifs_scale * raw.dx * 100;
> + round_up = data->rfs_res[chan->channel] / 2;
> + *val = (*val + round_up) / data->rfs_res[chan->channel];
> +
> + if (raw.source_bit == SINK_I)
> + *val = -*val;
> + *val = *val * 100; /* picoAmps */
> + return IIO_VAL_INT;
> +
> + case IIO_CHAN_INFO_SCALE:
> + round_up = data->rfs_res[chan->channel] / 2;
> + /* picoAmps */
> + *val = (data->ifs_scale * 10000 + round_up) /
> + data->rfs_res[chan->channel];
> + return IIO_VAL_INT;
> +
> + case IIO_CHAN_INFO_OFFSET:
> + *val = 0;
> + return IIO_VAL_INT;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +/**
> + * val is positive if sourcing
> + * val is negative if sinking
> + */
> +static int ds4424_write_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int val, int val2, long mask)
> +{
> + union raw_data raw;
> + struct ds4424_data *data = iio_priv(indio_dev);
> + int val0, max_val, min_val, tmp_scale;
> +
> + if (val2 != 0)
> + return -EINVAL;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> +
> + max_val = ((1 << chan->scan_type.realbits)/2) - 1;
spaces before and after /
> + min_val = -max_val;
> + if ((val > max_val) || (val < min_val))
parenthesis not needed
> + return -EINVAL;
> +
> + if (val > 0) {
> + raw.source_bit = SOURCE_I;
> + raw.dx = val;
> + } else {
> + raw.source_bit = SINK_I;
> + raw.dx = -val;
> + }
> +
> + return ds4424_set_value(indio_dev, raw.bits, chan);
> +
> + case IIO_CHAN_INFO_PROCESSED: /* val input is picoAmps */
> + /* val can be 0 to 200,000,000 (200 picoAmps) */
> + val0 = val;
> + raw.source_bit = SOURCE_I;
> + if (val < 0) {
> + raw.source_bit = SINK_I;
> + val = -val;
> + }
> + if (val > data->max_picoamp) {
> + pr_err("%s : Requested current %d ", __func__, val);
> + pr_err("exceeds %d picoAmps\n", data->max_picoamp);
> + return -EINVAL;
> + }
> + if (data->rfs_res[chan->channel] < data->min_rfs ||
> + data->rfs_res[chan->channel] > data->max_rfs) {
> + pr_info("%s : Resistor values out of range\n",
> + __func__);
> + return -EINVAL;
> + }
> + val = val / 1000;
> + tmp_scale = data->ifs_scale / 10; /* preserve resolution */
> + val = (val * data->rfs_res[chan->channel]) /
> + tmp_scale;
> + val = (val + 50) / 100;
> + val2 = ((1 << chan->scan_type.realbits) / 2) - 1;
> + if (val > val2) {
> + pr_info("%s : Requested current %d %d",
> + __func__, val0, val);
> + pr_info("exceeds maximum. DAC set to maximum %d\n",
> + val2);
> + val = val2;
> + }
> + raw.dx = val;
> + return ds4424_set_value(indio_dev, raw.bits, chan);
> +
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int ds4424_verify_chip(struct iio_dev *indio_dev)
> +{
> + int ret = 0, val;
> + int i;
> +
> + usleep_range(1000, 1200);
> + for (i = 0; i < indio_dev->num_channels; i++) {
> + ret = ds4424_get_value(indio_dev, &val, i);
> + if (ret < 0) {
> + pr_err("%s : read %d, should be 0\n", __func__, ret);
> + break;
> + }
> + }
> + return ret;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int ds4424_suspend(struct device *dev)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
> + struct ds4424_data *data = iio_priv(indio_dev);
> + int ret = 0;
> + u32 i;
> +
> + for (i = 0; i < indio_dev->num_channels; i++) {
> + data->save[i] = data->raw[i];
> + ret = ds4424_set_value(indio_dev, 0,
> + &(indio_dev->channels[i]));
&() parenthesis not needed, here and below
> + if (ret < 0)
> + return ret;
> + }
> + return ret;
> +}
> +
> +static int ds4424_resume(struct device *dev)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
> + struct ds4424_data *data = iio_priv(indio_dev);
> + int ret = 0;
> + u32 i;
> +
> + for (i = 0; i < indio_dev->num_channels; i++) {
> + ret = ds4424_set_value(indio_dev, data->save[i],
> + &(indio_dev->channels[i]));
> + if (ret < 0)
> + return ret;
> + }
> + return ret;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(ds4424_pm_ops, ds4424_suspend, ds4424_resume);
> +#define DS4424_PM_OPS (&ds4424_pm_ops)
> +#else
> +#define DS4424_PM_OPS NULL
> +#endif /* CONFIG_PM_SLEEP */
> +
> +static const struct iio_info ds4424_info = {
> + .read_raw = ds4424_read_raw,
> + .write_raw = ds4424_write_raw,
> + .driver_module = THIS_MODULE,
> +};
> +
> +#ifdef CONFIG_OF
> +static int ds4424_parse_dt(struct iio_dev *indio_dev)
> +{
> + int ret;
> + int len;
> + int num_ch;
> + int i;
> + int count;
> + struct property *prop;
> + struct ds4424_data *data = iio_priv(indio_dev);
> + struct device_node *node = indio_dev->dev.parent->of_node;
> +
> + if (!node) {
> + pr_info("%s:%d ds4424 dts not found\n", __func__, __LINE__);
> + return -ENODEV;
> + }
> +
> + prop = of_find_property(node, "rfs-resistors", &len);
> + if (!prop) {
> + pr_err("Invalid rfs-resistor in dt. len: %d\n", len);
> + return -EINVAL;
> + }
> +
> + if (len != (DS442X_MAX_DAC_CHANNELS * sizeof(uint32_t))) {
> + pr_err("Invalid rfs-resistor length in dt. len: %d\n", len);
> + return -EINVAL;
> + }
> +
> + ret = of_property_read_u32_array(node, "rfs-resistors",
> + data->rfs_res, DS442X_MAX_DAC_CHANNELS);
> + if (ret < 0) {
> + pr_err("Reading rfs-resistors from dt failed. ret: %d\n", ret);
> + return ret;
> + }
> +
> + pr_info("ds4424 rfs-resistors: %d, %d, %d, %d\n",
> + data->rfs_res[0], data->rfs_res[1],
> + data->rfs_res[2], data->rfs_res[3]);
> +
> + ret = of_property_read_u32(node, "max-rfs",
> + &data->max_rfs);
> + if (ret < 0) {
> + pr_err("Reading max-rfs from dt failed. ret: %d\n", ret);
> + return ret;
> + }
> +
> + ret = of_property_read_u32(node, "min-rfs",
> + (u32 *)&data->min_rfs);
> + if (ret < 0) {
> + pr_err("Reading min-rfs from dt failed. ret: %d\n", ret);
> + return ret;
> + }
> +
> + pr_info("ds4424 max-rfs: %d, min-rfs: %d\n",
> + data->max_rfs, data->min_rfs);
> +
> + ret = of_property_read_u32(node, "max-picoamp",
> + (u32 *)&data->max_picoamp);
> + if (ret < 0) {
> + pr_err("Reading max-picoamp from dt failed. ret: %d\n", ret);
> + return ret;
> + }
> +
> + ret = of_property_read_u32(node, "ifs-scale",
> + (u32 *)&data->ifs_scale);
> + if (ret < 0) {
> + pr_err("Reading ifs-scale from dt failed. ret: %d\n", ret);
> + return ret;
> + }
> +
> + pr_info("ds4424 max-picoamp: %d, ifs-scale: %d\n",
> + data->max_picoamp, data->ifs_scale);
> +
> + count = of_property_count_strings(node, "dac-iio-map");
> + if (count < 0) {
> + pr_info("dac-iio-map not found in dts\n");
> + return count;
> + }
> +
> + ret = of_property_read_string(node, "vcc-supply", &data->vcc_reg_name);
> + if (ret < 0) {
> + pr_info("DAC vcc-supply is not available in dts\n");
dt vs dts, here and below; maybe DT?
> + data->vcc_reg_name = NULL;
> + }
> +
> + if (count != DS4424_MAX_DAC_CHANNELS * 3 &&
> + count != DS4424_MAX_DAC_CHANNELS * 3) {
> + pr_info("Incorrect dac-iio-map in dts. count: %d\n", count);
> + return -EINVAL;
> + }
> +
> + num_ch = count / 3;
> + for (i = 0; i < num_ch; i++) {
> + ret = of_property_read_string_index(node,
> + "dac-iio-map", i * 3,
> + &data->dac_iio_map[i].consumer_dev_name);
> + if (ret < 0) {
> + pr_info("%s:%d\n", __func__, __LINE__);
> + return ret;
> + }
> +
> + ret = of_property_read_string_index(node, "dac-iio-map",
> + i * 3 + 1,
> + &data->dac_iio_map[i].consumer_channel);
> + if (ret < 0) {
> + pr_info("%s:%d\n", __func__, __LINE__);
> + return ret;
> + }
> +
> + ret = of_property_read_string_index(node, "dac-iio-map",
> + i * 3 + 2,
> + &data->dac_iio_map[i].adc_channel_label);
> + if (ret < 0) {
> + pr_info("%s:%d\n", __func__, __LINE__);
> + return ret;
> + }
> +
> + pr_info("ds4424 iio-map[%d]: %s, %s, %s\n", i,
> + data->dac_iio_map[i].consumer_dev_name,
> + data->dac_iio_map[i].consumer_channel,
> + data->dac_iio_map[i].adc_channel_label);
> + }
> +
> + return 0;
> +}
> +#else
> +static int ds4424_parse_dt(struct iio_dev *indio_dev)
> +{
> + return -ENODEV;
> +}
> +#endif
> +
> +static int ds4424_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + const struct ds4424_pdata *pdata;
> + struct ds4424_data *data;
> + struct iio_dev *indio_dev;
> + int ret;
> +
> + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
> + dev_err(&client->dev, "I2C is not supported\n");
> + return -ENODEV;
> + }
> +
> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> + if (!indio_dev) {
> + pr_err("%s:%d\n", __func__, __LINE__);
> + return -ENOMEM;
> + }
> +
> + data = iio_priv(indio_dev);
> + memset(data, 0, sizeof(*data));
> + i2c_set_clientdata(client, indio_dev);
> + data->client = client;
> + indio_dev->name = id->name;
> + indio_dev->dev.parent = &client->dev;
> +
> + ret = ds4424_verify_chip(indio_dev);
> + if (ret < 0) {
> + dev_err(&client->dev, "%s failed. ret:%d\n", __func__, ret);
> + return -ENXIO;
> + }
> +
> + if (client->dev.of_node) {
> + ret = ds4424_parse_dt(indio_dev);
> + if (ret < 0) {
> + dev_err(&client->dev,
> + "%s - of_node error\n", __func__);
> + ret = -EINVAL;
> + }
> + } else {
> + pdata = client->dev.platform_data;
extra spaces after =
> + if (!pdata) {
> + dev_err(&client->dev,
> + "dts/platform data not found.\n");
> + /* Use default driver settings */
> + pdata = &ds4424_pdata_default;
> + }
> +
> + pdata = client->dev.platform_data;
> + data->min_rfs = pdata->min_rfs;
> + data->max_rfs = pdata->max_rfs;
> + data->ifs_scale = pdata->ifs_scale;
> + data->max_picoamp = pdata->max_picoamp;
> + data->vcc_reg_name = pdata->vcc_supply_name;
> + memcpy(data->rfs_res, pdata->rfs_res,
> + sizeof(uint32_t) * DS442X_MAX_DAC_CHANNELS);
> + memcpy(data->dac_iio_map, pdata->dac_iio_map,
> + sizeof(struct iio_map) * DS442X_MAX_DAC_CHANNELS);
> + }
> +
> + if (data->vcc_reg_name) {
> + data->vcc_reg = devm_regulator_get(&client->dev,
> + data->vcc_reg_name);
> + if (IS_ERR(data->vcc_reg)) {
> + ret = PTR_ERR(data->vcc_reg);
> + dev_err(&client->dev,
> + "Failed to get vcc_reg regulator: %d\n", ret);
> + return ret;
> + }
> + }
> +
> + mutex_init(&data->lock);
> + ret = ds4424_regulator_onoff(indio_dev, PWR_ON);
> + if (ret < 0) {
> + pr_err("Unable to turn on the regulator. %s:%d, ret: %d\n",
> + __func__, __LINE__, ret);
> + return ret;
> + }
> +
> + switch (id->driver_data) {
> + case ID_DS4422:
> + indio_dev->num_channels = DS4422_MAX_DAC_CHANNELS;
> + break;
> + case ID_DS4424:
> + indio_dev->num_channels = DS4424_MAX_DAC_CHANNELS;
> + break;
> + default:
> + indio_dev->num_channels = DS4424_MAX_DAC_CHANNELS;
> + break;
> + }
> +
> + indio_dev->channels = ds4424_channels;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->info = &ds4424_info;
> +
> + ret = iio_map_array_register(indio_dev, data->dac_iio_map);
> + if (ret < 0)
> + goto err_iio_device_0;
> +
> + ret = iio_device_register(indio_dev);
> + if (ret < 0) {
> + pr_err("iio_device_register failed . %s:%d, ret: %d\n",
delete space after 'failed'
> + __func__, __LINE__, ret);
> + goto err_iio_device_1;
> + }
> +
> + return ret;
> +
> +err_iio_device_0:
> + ds4424_regulator_onoff(indio_dev, PWR_OFF);
> +err_iio_device_1:
> + iio_map_array_unregister(indio_dev);
> + return ret;
> +}
> +
> +static int ds4424_remove(struct i2c_client *client)
> +{
> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +
> + iio_device_unregister(indio_dev);
> + iio_map_array_unregister(indio_dev);
> + ds4424_regulator_onoff(indio_dev, PWR_OFF);
> + return 0;
> +}
> +
> +static const struct i2c_device_id ds4424_id[] = {
> + { "ds4422", ID_DS4422 },
> + { "ds4424", ID_DS4424 },
> + { }
> +};
> +MODULE_DEVICE_TABLE(i2c, ds4424_id);
> +
> +static const struct of_device_id ds4424_of_match[] = {
> + { .compatible = "maxim,ds4422" },
> + { .compatible = "maxim,ds4424" },
> + { }
> +};
> +
> +MODULE_DEVICE_TABLE(of, ds4424_of_match);
> +
> +static struct i2c_driver ds4424_driver = {
> + .driver = {
> + .name = "ds4424",
> + .pm = DS4424_PM_OPS,
> + },
> + .probe = ds4424_probe,
> + .remove = ds4424_remove,
> + .id_table = ds4424_id,
> +};
> +module_i2c_driver(ds4424_driver);
> +
> +MODULE_DESCRIPTION("Maxim DS4424 DAC Driver");
> +MODULE_AUTHOR("Ismail H. Kose <ismail.kose-zxKO94PEStzToO697jQleEEOCMrvLtNR@public.gmane.org>");
> +MODULE_AUTHOR("Vishal Sood <vishal.sood-zxKO94PEStzToO697jQleEEOCMrvLtNR@public.gmane.org>");
> +MODULE_AUTHOR("David Jung <david.jung-zxKO94PEStzToO697jQleEEOCMrvLtNR@public.gmane.org>");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/iio/dac/ds4424.h b/include/linux/iio/dac/ds4424.h
> new file mode 100644
> index 000000000000..09ff3d61797d
> --- /dev/null
> +++ b/include/linux/iio/dac/ds4424.h
> @@ -0,0 +1,29 @@
> +/*
> + * Maxim Integrated
> + * 7-bit, Multi-Channel Sink/Source Current DAC Driver
> + * Copyright (C) 2017 Maxim Integrated
> + *
> + * 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.
> + */
> +
> +#ifndef IIO_DAC_DS4424_H_
> +#define IIO_DAC_DS4424_H_
> +#include <linux/iio/iio.h>
> +#include <linux/iio/machine.h>
> +
> +#define DS4422_MAX_DAC_CHANNELS 2
> +#define DS4424_MAX_DAC_CHANNELS 4
> +#define DS442X_MAX_DAC_CHANNELS DS4424_MAX_DAC_CHANNELS
> +
> +struct ds4424_pdata {
> + const char *vcc_supply_name;
> + uint32_t max_rfs;
> + uint32_t min_rfs;
> + uint32_t ifs_scale;
> + uint32_t max_picoamp;
> + uint32_t rfs_res[DS442X_MAX_DAC_CHANNELS];
> + struct iio_map dac_iio_map[DS442X_MAX_DAC_CHANNELS + 1];
> +};
> +#endif /* IIO_DAC_DS4424_H_ */
>
--
Peter Meerwald-Stadler
Mobile: +43 664 24 44 418
next prev parent reply other threads:[~2017-06-25 21:34 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-23 23:04 [PATCH] iio: dac: DS4424: add Maxim DS4422/DS4424 DAC driver support Ismail Kose
2017-06-23 23:04 ` Ismail Kose
2017-06-24 17:37 ` Jonathan Cameron
2017-06-24 17:37 ` Jonathan Cameron
2017-06-25 21:33 ` Peter Meerwald-Stadler [this message]
2017-06-25 21:33 ` Peter Meerwald-Stadler
2017-06-26 19:56 ` Rob Herring
2017-06-26 19:56 ` Rob Herring
2017-06-29 12:47 ` Linus Walleij
2017-06-29 12:47 ` Linus Walleij
2017-09-18 22:09 ` [PATCH v3] iio: dac: ds4422/ds4424 dac driver Ismail Kose
2017-09-18 22:09 ` Ismail Kose
2017-09-19 4:48 ` Peter Meerwald-Stadler
2017-09-19 4:48 ` Peter Meerwald-Stadler
2017-09-19 6:24 ` Ismail Kose
2017-09-19 6:24 ` Ismail Kose
2017-09-19 7:23 ` [PATCH v5] " Ismail Kose
2017-09-19 7:23 ` Ismail Kose
2017-09-19 7:23 ` Ismail Kose
2017-09-21 23:26 ` Rob Herring
2017-09-21 23:26 ` Rob Herring
2017-09-22 15:09 ` Jonathan Cameron
2017-09-22 15:09 ` Jonathan Cameron
2017-09-19 7:06 ` [PATCH v4] " Ismail Kose
2017-09-19 7:06 ` Ismail Kose
2017-09-19 13:34 ` [PATCH v3] " kbuild test robot
2017-09-19 13:34 ` kbuild test robot
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