> > This patch provides an iio device driver for DS4422/DS4424 chips that support > > two/four channel 7-bit Sink/Source Current DAC. some additional comments below > > The driver supports device tree and platform files for the configurations. > > So silly question to start things off. Do you actually have users for this > who are using platform data still? If not there is no obligation at all > to provide platform data configuration. If you do then it's fine to provide > support. > > > > > Datasheet publicly available at: > > https://datasheets.maximintegrated.com/en/ds/DS4422-DS4424.pdf > > > > Signed-off-by: Ismail Kose <Ismail.Kose@xxxxxxxxxxxxxxxxxxx> > > --- > > This is version 2 of the driver? So should have [PATCH V2] at the > start of the subject and a revision history here under the cut line > but above the stats. > > > drivers/iio/dac/Kconfig | 9 + > > drivers/iio/dac/Makefile | 1 + > > drivers/iio/dac/ds4424.c | 476 +++++++++++++++++++++++++++++++++++++++++ > > include/linux/iio/dac/ds4424.h | 24 +++ > > Given this is platform data only, it now belongs in /include/linux/platform_data. > (a change that occurred a few years back) > > > 4 files changed, 510 insertions(+) > > create mode 100644 drivers/iio/dac/ds4424.c > > create mode 100644 include/linux/iio/dac/ds4424.h > > > > 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. > > + > > 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 > > diff --git a/drivers/iio/dac/ds4424.c b/drivers/iio/dac/ds4424.c > > new file mode 100644 > > index 000000000000..8765bf20ab62 > > --- /dev/null > > +++ b/drivers/iio/dac/ds4424.c > > @@ -0,0 +1,476 @@ > > +/* > > + * 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> > > +#include <linux/iio/dac/ds4424.h> > > + > > +#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), \ > > + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET), \ driver doesn't implement INFO_OFFSET > > + .address = DS4424_DAC_ADDR(chan), \ > > + .scan_type = { \ driver doesn't support buffered mode, no need for scan_type > > + .sign = 'u', \ > > + .realbits = 8, \ > > + .storagebits = 8, \ > > + }, \ > > +} > > + > > +union ds4424_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[DS4424_MAX_DAC_CHANNELS]; > > + __maybe_unused uint16_t save[DS4424_MAX_DAC_CHANNELS]; > > + uint32_t rfs_res[DS4424_MAX_DAC_CHANNELS]; > > + struct regulator *vcc_reg; > > +}; > > + > > +static struct iio_map ds4424_iio_maps[] = { > > + { .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" > > + }, > > + { }, > > This doesn't belong in the driver at all. Could you describe what the > intent of this map is? > > > +}; > > + > > + > > +static const struct ds4424_pdata ds4424_pdata = { > > + .rfs_res = {400, 800, 1000, 1600}, > > + .dac_iio_map = ds4424_iio_maps, > > +}; > > + > > +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_write_byte_data(data->client, > > + DS4424_DAC_ADDR(channel), 1); 1 seems to indicate a register of the device, maybe use a #define to name it? > > + if (ret < 0) > > + goto fail; > > + > > + ret = i2c_smbus_read_byte_data(data->client, 1); > > + if (ret < 0) > > + goto fail; > > + > > + *val = ret; > > + mutex_unlock(&data->lock); > > + return 0; > > + > > +fail: > > + mutex_unlock(&data->lock); > > + return ret; > > +} > > + > > +/* > > + * 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 complemental code considering the bit[6:0] is a absolute is not a two's complement > > + * 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); > > + int ret; > > + > > + if (val < 0 || val > U8_MAX) > > + return -EINVAL; the comment says val is -127..127? > > + > > + 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; why is raw uint16_t and not uint8_t? > > + 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_MAX || val < S8_MIN) S8_MIN is -128, not -127? > > + 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; > > + > > + ret = ds4424_get_value(indio_dev, &val, DS4424_DAC_ADDR(0)); > > + if (ret < 0) > > + dev_err(&indio_dev->dev, > > + "ds4424 i2c read failed. ret: %d\n", ret); > > The error message could more informative of 'what read' failed. > Either that or get rid of it entirely as it provides very little information. > > + > > + 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; > > + u32 i; i should be int or unsigned int maybe > > + > > + 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; > > + 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); > > + > > +static const struct iio_info ds4424_info = { > > + .read_raw = ds4424_read_raw, > > + .write_raw = ds4424_write_raw, > > + .driver_module = THIS_MODULE, > > Specifying .driver_module is now handled by some macro magic. > Don't worry about this though, I'll just fix it up when applying > (this cycle) as the code for that change is only in my branches for > the next cycle. > > > +}; > > + > > +#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); > > This binding needs documenting. Given you had documentation in v1 it is > a little surprising not to see it here. > > > + 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]); > > + > > + count = of_property_count_strings(node, "maxim,dac-iio-map"); > > + if (count < 0) { > > + pr_info("ds4424 maxim,dac-iio-map not found in DT\n"); > > + return count; > > + } > > + > > + if (count != DS4424_MAX_DAC_CHANNELS * 3 && > > + count != DS4424_MAX_DAC_CHANNELS * 3) { > > + pr_info("ds4424 maxim,dac-iio-map in DT not valid.\n"); > > + return -EINVAL; > > + } > > + > > + 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; > > + > > + 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) { > > + 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; > > + } > > + } else { > > + pdata = client->dev.platform_data; > > + if (!pdata) { > > + dev_err(&client->dev, > > + "dts/platform data not found.\n"); > > + pdata = &ds4424_pdata; > > + } > > + > > + pdata = client->dev.platform_data; > > + memcpy(data->rfs_res, pdata->rfs_res, > > + sizeof(uint32_t) * DS4424_MAX_DAC_CHANNELS); > > + } > > + > > + 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"); > > + indio_dev->num_channels = DS4424_MAX_DAC_CHANNELS; > > I would fault out here rather than effectively guessing.. The configuration > is inconsistent so we shouldn't just try to carry on. > > > + break; > > + } > > + > > + indio_dev->channels = ds4424_channels; > > + indio_dev->modes = INDIO_DIRECT_MODE; > > + indio_dev->info = &ds4424_info; > > + > > + ret = iio_map_array_register(indio_dev, ds4424_pdata.dac_iio_map); > > + if (ret < 0) > > + goto err_iio_map_register; > > + > > + ret = iio_device_register(indio_dev); > > + if (ret < 0) { > > + dev_err(&client->dev, > > + "iio_device_register failed. ret: %d\n", ret); > > + goto err_iio_dev_register; > > + } > > + > > + return ret; > > + > > +err_iio_map_register: > > + regulator_disable(data->vcc_reg); > > + > > +err_iio_dev_register: > > + 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); > > + struct ds4424_data *data = iio_priv(indio_dev); > > + > > + iio_device_unregister(indio_dev); > > + iio_map_array_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" }, > > + { } > > +}; > > + > > For consistency don't have a blank line here. > > > +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.kose@xxxxxxxxxxxxxxxxxxx>"); > > +MODULE_AUTHOR("Vishal Sood <vishal.sood@xxxxxxxxxxxxxxxxxxx>"); > > +MODULE_AUTHOR("David Jung <david.jung@xxxxxxxxxxxxxxxxxxx>"); > > +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..2c814118df38 > > --- /dev/null > > +++ b/include/linux/iio/dac/ds4424.h > > @@ -0,0 +1,24 @@ > > +/* > > + * 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 > > + > > +struct ds4424_pdata { > > + const char *vcc_supply_name; > > + uint32_t rfs_res[DS4424_MAX_DAC_CHANNELS]; > > + struct iio_map *dac_iio_map; > > +}; > > +#endif /* IIO_DAC_DS4424_H_ */ > > -- > To unsubscribe from this list: send the line "unsubscribe linux-iio" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- Peter Meerwald-Stadler Mobile: +43 664 24 44 418 -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
