You can find my reply to one of your comments below. > -----Original Message----- > From: Peter Meerwald-Stadler [mailto:pmeerw@xxxxxxxxxx] > Sent: Monday, September 18, 2017 9:49 PM > To: Ismail Kose <Ismail.Kose@xxxxxxxxxxxxxxxxxxx> > Cc: ihkose@xxxxxxxxx; Jonathan Cameron <jic23@xxxxxxxxxx>; Hartmut > Knaack <knaack.h@xxxxxx>; Lars-Peter Clausen <lars@xxxxxxxxxx>; Rob > Herring <robh+dt@xxxxxxxxxx>; Mark Rutland <mark.rutland@xxxxxxx>; > Maxime Roussin-Belanger <maxime.roussinbelanger@xxxxxxxxx>; Mike > Looijmans <mike.looijmans@xxxxxxxx>; Peter Rosin <peda@xxxxxxxxxx>; > Fabrice Gasnier <fabrice.gasnier@xxxxxx>; Jean-Francois Dagenais > <jeff.dagenais@xxxxxxxxx>; linux-iio@xxxxxxxxxxxxxxx; > devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx > Subject: Re: [PATCH v3] iio: dac: ds4422/ds4424 dac driver > > EXTERNAL EMAIL > > > > > 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.Kose@xxxxxxxxxxxxxxxxxxx> > > --- > > 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://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flkml. > org%2Flkml%2F2017%2F9%2F14%2F546&data=01%7C01%7CIsmail.Kose%40 > maximintegrated.com%7C1bb4c28e4d3642f3ccc508d4ff19aecb%7Cfbd909dfe > a694788a554f24b7854ad03%7C0&sdata=ICps6DntgtUajBSjXi%2BH4oM1iFq3ia > Wdq9aubdpU2wI%3D&reserved=0) > > * 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://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdata > > +sheets.maximintegrated.com%2Fen%2Fds%2FDS4422- > DS4424.pdf&data=01%7C01 > > > +%7CIsmail.Kose%40maximintegrated.com%7C1bb4c28e4d3642f3ccc508d4ff > 19ae > > > +cb%7Cfbd909dfea694788a554f24b7854ad03%7C0&sdata=QhkGknhcRzCmek > %2B4Vul > > +6gCOO8QVNMWSAzz71tP5boTc%3D&reserved=0 > > + > > +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 -128 is acceptable input for the function. 0 and -128 both will have output current zero. This should be right. > > > > + 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.kose@xxxxxxxxxxxxxxxxxxx>"); > > +MODULE_AUTHOR("Vishal Sood <vishal.sood@xxxxxxxxxxxxxxxxxxx>"); > > +MODULE_AUTHOR("David Jung <david.jung@xxxxxxxxxxxxxxxxxxx>"); > > +MODULE_LICENSE("GPL v2"); > > > > -- > > Peter Meerwald-Stadler > Mobile: +43 664 24 44 418 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
