> This patch provides an iio device driver for DS4422/DS4424 chips that support > two/four channel 7-bit Sink/Source Current DAC.
some more minor comments below > Signed-off-by: Ismail Kose <ismail.k...@maximintegrated.com> > --- > v3: > * Removed iio-map and platform file support > * Removed ds4424.h file > * Fixed ADC value read bug > * Removed confused comments > * Added device tree binding file > * Fixed bugs in probe and read function > > v2: (https://lkml.org/lkml/2017/9/14/546) > * Fixed coding style and removed unncessary code > * Removed min/max rfs, ifs-scale, etc values from device tree > * Removed unused code, definitions and some comments > * Removed regulator control and made standard structure > * Removed data processing and channel scale > * Removed device tree binding file > > .../devicetree/bindings/iio/dac/ds4424.txt | 20 ++ > drivers/iio/dac/Kconfig | 9 + > drivers/iio/dac/Makefile | 1 + > drivers/iio/dac/ds4424.c | 399 > +++++++++++++++++++++ > 4 files changed, 429 insertions(+) > create mode 100644 Documentation/devicetree/bindings/iio/dac/ds4424.txt > create mode 100644 drivers/iio/dac/ds4424.c > > diff --git a/Documentation/devicetree/bindings/iio/dac/ds4424.txt > b/Documentation/devicetree/bindings/iio/dac/ds4424.txt > new file mode 100644 > index 000000000000..840b11e1d813 > --- /dev/null > +++ b/Documentation/devicetree/bindings/iio/dac/ds4424.txt > @@ -0,0 +1,20 @@ > +Maxim Integrated DS4422/DS4424 7-bit Sink/Source Current DAC Device Driver > + > +Datasheet publicly available at: > +https://datasheets.maximintegrated.com/en/ds/DS4422-DS4424.pdf > + > +Required properties: > + - compatible: Must be "maxim,ds4422" or "maxim,ds4424" > + - reg: Should contain the DAC I2C address > + - maxim,rfs-resistors-ohms: Should contain reference resistor > + > +Optional properties: > + - vcc-supply: Power supply is optional. If not defined, driver will > ignore it. > + > +Example: > + ds4224@10 { > + compatible = "maxim,ds4424"; > + reg = <0x10>; /* When A0, A1 pins are ground */ > + vcc-supply = "dac_vcc_3v3"; > + maxim,rfs-resistors-ohms = <400 800 1000 1600>; > + }; > diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig > index 25bed2d7d2b9..db6ceba1c76f 100644 > --- a/drivers/iio/dac/Kconfig > +++ b/drivers/iio/dac/Kconfig > @@ -310,4 +310,13 @@ config VF610_DAC > This driver can also be built as a module. If so, the module will > be called vf610_dac. > > +config DS4424 > + tristate "Maxim Integrated DS4422/DS4424 DAC driver" > + depends on I2C > + help > + If you say yes here you get support for Maxim chips DS4422, DS4424. > + > + This driver can also be built as a module. If so, the module > + will be called ds4424. alphabetic order please + > endmenu > diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile > index 603587cc2f07..f29f929a0587 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_DS4424) += ds4424.o alphabetic order please > diff --git a/drivers/iio/dac/ds4424.c b/drivers/iio/dac/ds4424.c > new file mode 100644 > index 000000000000..46ae28081cf0 > --- /dev/null > +++ b/drivers/iio/dac/ds4424.c > @@ -0,0 +1,399 @@ > +/* > + * 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/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/consumer.h> > + > +#define DS4422_MAX_DAC_CHANNELS 2 > +#define DS4424_MAX_DAC_CHANNELS 4 > + > +#define DS4424_DAC_ADDR(chan) ((chan) + 0xf8) > +#define DS4424_SOURCE_I 1 > +#define DS4424_SINK_I 0 > + > +#define DS4424_CHANNEL(chan) { \ > + .type = IIO_CURRENT, \ > + .indexed = 1, \ > + .output = 1, \ > + .channel = chan, \ > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ > + .address = DS4424_DAC_ADDR(chan), \ .address is not used > +} > + > +/* > + * DS4424 DAC control register 8 bits > + * [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 two's complement code considering the bit[6:0] is a absolute > + * distance from the zero point. > + */ > +union ds4424_raw_data { > + struct { > + u8 dx:7; > + u8 source_bit:1; > + }; > + u8 bits; > +}; > + > +enum ds4424_device_ids { > + ID_DS4422, > + ID_DS4424, > +}; > + > +struct ds4424_data { > + struct i2c_client *client; > + struct mutex lock; > + __maybe_unused uint16_t save[DS4424_MAX_DAC_CHANNELS]; save should ba uint8_t as well (to match raw) > + uint32_t rfs_res[DS4424_MAX_DAC_CHANNELS]; > + struct regulator *vcc_reg; > + uint8_t raw[DS4424_MAX_DAC_CHANNELS]; > +}; > + > +static const struct iio_chan_spec ds4424_channels[] = { > + DS4424_CHANNEL(0), > + DS4424_CHANNEL(1), > + DS4424_CHANNEL(2), > + DS4424_CHANNEL(3), > +}; > + > +static int ds4424_get_value(struct iio_dev *indio_dev, > + int *val, int channel) > +{ > + struct ds4424_data *data = iio_priv(indio_dev); > + int ret; > + > + mutex_lock(&data->lock); > + ret = i2c_smbus_read_byte_data(data->client, DS4424_DAC_ADDR(channel)); > + if (ret < 0) > + goto fail; > + > + *val = ret; > + mutex_unlock(&data->lock); > + return 0; > + > +fail: > + mutex_unlock(&data->lock); > + return ret; > +} > + > +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); > + int ret; > + > + if (val < 0 || val > U8_MAX) > + return -EINVAL; the check here is not necessary, _write_raw() already does the check > + > + mutex_lock(&data->lock); > + ret = i2c_smbus_write_byte_data(data->client, > + DS4424_DAC_ADDR(chan->channel), val); > + if (ret < 0) { > + mutex_unlock(&data->lock); > + return ret; > + } > + > + data->raw[chan->channel] = val; > + mutex_unlock(&data->lock); > + > + 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 ds4424_raw_data raw; > + int ret; > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + 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 == DS4424_SINK_I) > + *val = -*val; > + return IIO_VAL_INT; > + > + default: > + return -EINVAL; > + } > +} > + > +static int ds4424_write_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int val, int val2, long mask) > +{ > + union ds4424_raw_data raw; > + > + if (val2 != 0) > + return -EINVAL; > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + if (val < S8_MIN || val > S8_MAX) no, S8_MAX and S8_MIN is 127 and -128, resp. -128 is wront, should be -127 I think > + return -EINVAL; > + > + if (val > 0) { > + raw.source_bit = DS4424_SOURCE_I; > + raw.dx = val; > + } else { > + raw.source_bit = DS4424_SINK_I; > + 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; no need to init ret > + > + ret = ds4424_get_value(indio_dev, &val, DS4424_DAC_ADDR(0)); > + if (ret < 0) > + dev_err(&indio_dev->dev, > + "%s failed. ret: %d\n", __func__, ret); > + > + return ret; > +} > + > +static int __maybe_unused 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; > + int 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]); > + if (ret < 0) > + return ret; > + } > + return ret; > +} > + > +static int __maybe_unused 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; > + int 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); > + > +static const struct iio_info ds4424_info = { > + .read_raw = ds4424_read_raw, > + .write_raw = ds4424_write_raw, > +}; > + > +#ifdef CONFIG_OF > +static int ds4424_parse_dt(struct iio_dev *indio_dev) > +{ > + int ret; > + int len; > + int count; > + struct property *prop; > + struct ds4424_data *data = iio_priv(indio_dev); > + struct device_node *node = indio_dev->dev.of_node; > + > + if (!node) { > + pr_info("%s:%d ds4424 DT not found\n", __func__, __LINE__); > + return -ENODEV; > + } > + > + prop = of_find_property(node, "maxim,rfs-resistors-ohms", &len); > + if (!prop) { > + pr_err("ds4424 maxim,rfs-resistor not found in DT.\n"); > + return -EINVAL; > + } > + > + if (len != (DS4424_MAX_DAC_CHANNELS * sizeof(uint32_t))) { > + pr_err("ds4424 maxim,rfs-resistor length in DT not valid.\n"); > + return -EINVAL; > + } > + > + ret = of_property_read_u32_array(node, "maxim,rfs-resistors-ohms", > + data->rfs_res, DS4424_MAX_DAC_CHANNELS); > + if (ret < 0) { > + pr_err("ds4424 reading maxim,rfs-resistors from DT failed.\n"); > + return ret; > + } > + > + pr_info("ds4424 maxim,rfs-resistors: %d, %d, %d, %d\n", > + data->rfs_res[0], data->rfs_res[1], > + data->rfs_res[2], data->rfs_res[3]); > + > + 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) > +{ > + struct ds4424_data *data; > + struct iio_dev *indio_dev; > + int ret; > + > + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); > + if (!indio_dev) { > + dev_err(&client->dev, "iio dev alloc failed.\n"); > + return -ENOMEM; > + } > + > + data = iio_priv(indio_dev); > + i2c_set_clientdata(client, indio_dev); > + data->client = client; > + indio_dev->name = id->name; > + indio_dev->dev.of_node = client->dev.of_node; > + indio_dev->dev.parent = &client->dev; > + > + if (!client->dev.of_node) { > + dev_err(&client->dev, > + "Not found DT.\n"); > + return -EPERM; > + } > + > + indio_dev->dev.of_node = client->dev.of_node; > + ret = ds4424_parse_dt(indio_dev); > + if (ret < 0) { > + dev_err(&client->dev, > + "%s - of_node error\n", __func__); > + return -EINVAL; > + } > + > + data->vcc_reg = devm_regulator_get(&client->dev, "vcc"); > + if (IS_ERR(data->vcc_reg)) { > + ret = PTR_ERR(data->vcc_reg); > + dev_err(&client->dev, > + "Failed to get vcc-supply regulator: %d\n", ret); > + return ret; > + } > + > + mutex_init(&data->lock); > + ret = regulator_enable(data->vcc_reg); > + if (ret < 0) { > + dev_err(&client->dev, > + "Unable to enable the regulator.\n"); > + return ret; > + } > + > + usleep_range(1000, 1200); > + ret = ds4424_verify_chip(indio_dev); > + if (ret < 0) > + return -ENXIO; > + > + 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: > + dev_err(&client->dev, > + "ds4424: Invalid chip id.\n"); > + regulator_disable(data->vcc_reg); > + return -ENXIO; > + } > + > + indio_dev->channels = ds4424_channels; > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->info = &ds4424_info; > + > + ret = iio_device_register(indio_dev); > + if (ret < 0) { > + dev_err(&client->dev, > + "iio_device_register failed. ret: %d\n", ret); > + regulator_disable(data->vcc_reg); > + } > + > + return ret; > +} > + > +static int ds4424_remove(struct i2c_client *client) > +{ > + struct iio_dev *indio_dev = i2c_get_clientdata(client); > + struct ds4424_data *data = iio_priv(indio_dev); > + > + iio_device_unregister(indio_dev); > + regulator_disable(data->vcc_reg); > + > + 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", > + .of_match_table = ds4424_of_match, > + .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.k...@maximintegrated.com>"); > +MODULE_AUTHOR("Vishal Sood <vishal.s...@maximintegrated.com>"); > +MODULE_AUTHOR("David Jung <david.j...@maximintegrated.com>"); > +MODULE_LICENSE("GPL v2"); > -- Peter Meerwald-Stadler Mobile: +43 664 24 44 418
