On 08/22/13 09:53, Angelo Compagnucci wrote: > Fixed read IIO_CHAN_INFO_SCALE when on differential input, fixed scale available > attribute name. > > Please review it! > > Thank you! > > Angelo > > > Signed-off-by: Angelo Compagnucci <angelo.compagnucci@xxxxxxxxx> Hi Angelo. A few issues have snuck in as a result of earlier changes. Please see comments inline. Jonathan > --- > drivers/iio/adc/Kconfig | 10 ++ > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/mcp3422.c | 401 +++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 412 insertions(+) > create mode 100644 drivers/iio/adc/mcp3422.c > > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index 09371cb..0cf5c61 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -145,6 +145,16 @@ config MCP320X > This driver can also be built as a module. If so, the module will be > called mcp320x. > > +config MCP3422 > + tristate "Microchip Technology MCP3422/3/4 driver" > + depends on I2C > + help > + Say yes here to build support for Microchip Technology's MCP3422, > + MCP3423 or MCP3424 analog to digital converters. > + > + This driver can also be built as a module. If so, the module will be > + called mcp3422. > + > config NAU7802 > tristate "Nuvoton NAU7802 ADC driver" > depends on I2C > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > index 33656ef..ba9a10a 100644 > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -16,6 +16,7 @@ obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o > obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o > obj-$(CONFIG_MAX1363) += max1363.o > obj-$(CONFIG_MCP320X) += mcp320x.o > +obj-$(CONFIG_MCP3422) += mcp3422.o > obj-$(CONFIG_NAU7802) += nau7802.o > obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o > obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o > diff --git a/drivers/iio/adc/mcp3422.c b/drivers/iio/adc/mcp3422.c > new file mode 100644 > index 0000000..db17833 > --- /dev/null > +++ b/drivers/iio/adc/mcp3422.c > @@ -0,0 +1,401 @@ > +/* > + * mcp3422.c - driver for the Microchip mcp3422/3/4 chip family > + * > + * Copyright (C) 2013, Angelo Compagnucci > + * Author: Angelo Compagnucci <angelo.compagnucci@xxxxxxxxx> > + * > + * Datasheet: http://ww1.microchip.com/downloads/en/devicedoc/22088b.pdf > + * > + * This driver exports the value of analog input voltage to sysfs, the > + * voltage unit is nV. > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + */ > + > +#include <linux/err.h> > +#include <linux/i2c.h> > +#include <linux/module.h> > +#include <linux/delay.h> > +#include <linux/sysfs.h> > + > +#include <linux/iio/iio.h> > +#include <linux/iio/sysfs.h> > + > +/* Masks */ > +#define MCP3422_CHANNEL_MASK 0x60 > +#define MCP3422_PGA_MASK 0x03 > +#define MCP3422_SRATE_MASK 0x0C > +#define MCP3422_SRATE_240 0x0 > +#define MCP3422_SRATE_60 0x1 > +#define MCP3422_SRATE_15 0x2 > +#define MCP3422_SRATE_3 0x3 > +#define MCP3422_PGA_1 0 > +#define MCP3422_PGA_2 1 > +#define MCP3422_PGA_4 2 > +#define MCP3422_PGA_8 3 > +#define MCP3422_CONT_SAMPLING 0x10 > + > +#define MCP3422_CHANNEL(config) (((config) & MCP3422_CHANNEL_MASK) >> 5) > +#define MCP3422_PGA(config) ((config) & MCP3422_PGA_MASK) > +#define MCP3422_SAMPLE_RATE(config) (((config) & MCP3422_SRATE_MASK) >> 2) > + > +#define MCP3422_CHANNEL_VALUE(value) (((value) << 5) & MCP3422_CHANNEL_MASK) > +#define MCP3422_PGA_VALUE(value) ((value) & MCP3422_PGA_MASK) > +#define MCP3422_SAMPLE_RATE_VALUE(value) ((value << 2) & MCP3422_SRATE_MASK) > + > +#define MCP3422_CHAN(_index) \ > + { \ > + .type = IIO_VOLTAGE, \ > + .indexed = 1, \ > + .channel = _index, \ > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \ > + | BIT(IIO_CHAN_INFO_SCALE), \ > + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ), \ > + } > + > +/* LSB is in nV to eliminate floating point */ > +static const u32 rates_to_lsb[] = {1000000, 250000, 62500, 15625}; > + > +/* Client data (each client gets its own) */ > +struct mcp3422 { > + struct i2c_client *i2c; > + u8 config; > + u8 pga[4]; > + struct mutex lock; > +}; > + > +static int mcp3422_update_config(struct mcp3422 *adc, u8 newconfig) > +{ > + int ret; > + > + mutex_lock(&adc->lock); > + > + ret = i2c_master_send(adc->i2c, &newconfig, 1); > + if (ret > 0) > + adc->config = newconfig; > + > + mutex_unlock(&adc->lock); > + > + return ret; > +} > + > +static int mcp3422_read(struct mcp3422 *adc, int *value, u8 *config) > +{ > + int ret = 0; > + u8 sample_rate = MCP3422_SAMPLE_RATE(adc->config); > + u8 buf[4] = {0, 0, 0, 0}; > + u32 temp; > + > + if (sample_rate == MCP3422_SRATE_3) { > + ret = i2c_master_recv(adc->i2c, buf, 4); > + temp = buf[0] << 16 | buf[1] << 8 | buf[2]; > + *config = buf[3]; > + } else { > + ret = i2c_master_recv(adc->i2c, buf, 3); This one is a standard endian conversion. > + temp = buf[0] << 8 | buf[1]; > + *config = buf[2]; > + } > + > + switch (sample_rate) { > + case MCP3422_SRATE_240: > + *value = sign_extend32(temp, 12); > + break; > + case MCP3422_SRATE_60: > + *value = sign_extend32(temp, 14); > + break; > + case MCP3422_SRATE_15: > + *value = sign_extend32(temp, 16); > + break; > + case MCP3422_SRATE_3: > + *value = sign_extend32(temp, 18); > + break; > + } > + > + return ret; > +} > + > +static int mcp3422_read_channel(struct mcp3422 *adc, > + struct iio_chan_spec const *channel, int *value) > +{ > + int mtime = 0; > + u8 config = 0; > + u8 req_channel = channel->channel; > + > + if (req_channel != MCP3422_CHANNEL(adc->config)) { > + config = adc->config; > + config &= ~MCP3422_CHANNEL_MASK; > + config |= MCP3422_CHANNEL_VALUE(req_channel); > + config &= ~MCP3422_PGA_MASK; > + config |= MCP3422_PGA_VALUE(adc->pga[req_channel]); > + mcp3422_update_config(adc, config); Update config can return an error. you should handle it. > + switch (MCP3422_SAMPLE_RATE(config)) { > + case MCP3422_SRATE_240: > + mtime = 1000 / 240; > + break; > + case MCP3422_SRATE_60: > + mtime = 1000 / 60; > + break; > + case MCP3422_SRATE_15: > + mtime = 1000 / 15; > + break; > + case MCP3422_SRATE_3: > + mtime = 1000 / 3; > + break; > + } > + msleep(mtime); > + } > + > + return mcp3422_read(adc, value, &config); > +} > + > +static int mcp3422_read_raw(struct iio_dev *iio, > + struct iio_chan_spec const *channel, int *val1, > + int *val2, long mask) > +{ > + struct mcp3422 *adc = iio_priv(iio); > + int err, temp = 0; > + > + u8 sample_rate = MCP3422_SAMPLE_RATE(adc->config); > + u8 pga = MCP3422_PGA(adc->config); > + This name is a little missleading as it gets the config as well. It does not seem to be used for the sampling frequency case so you should reorder the code so we don't get an unwanted read. > + err = mcp3422_read_channel(adc, channel, &temp); > + if (err < 0) > + return err; > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + *val1 = temp; > + > + return IIO_VAL_INT; > + > + case IIO_CHAN_INFO_SCALE: > + > + temp = (temp * rates_to_lsb[sample_rate]) > + / (pga ? 1 << pga : 1); > + > + *val1 = temp / 1000000000; > + *val2 = abs(temp % 1000000000); > + return IIO_VAL_INT_PLUS_NANO; > + > + case IIO_CHAN_INFO_SAMP_FREQ: > + switch (MCP3422_SAMPLE_RATE(adc->config)) { > + case MCP3422_SRATE_240: > + *val1 = 240; > + break; > + case MCP3422_SRATE_60: > + *val1 = 60; > + break; > + case MCP3422_SRATE_15: > + *val1 = 15; > + break; > + case MCP3422_SRATE_3: > + *val1 = 3; > + break; > + } > + return IIO_VAL_INT; > + > + default: > + break; > + } > + > + return -EINVAL; > +} > + > +static int mcp3422_write_raw(struct iio_dev *iio, > + struct iio_chan_spec const *channel, int val1, > + int val2, long mask) > +{ > + struct mcp3422 *adc = iio_priv(iio); > + u8 temp; > + u8 config = adc->config; > + u8 req_channel = channel->channel; > + > + switch (mask) { > + case IIO_CHAN_INFO_SCALE: Here you are writing integer values 1,2,4,8 yet the read is returning the correct scale values. You should do the magic to allow the writing of the same values here and you read back. Doing this can obviously be a little fiddly, but it gives userspace a much more consistent and predictable interface. > + switch (val1) { > + case 1: > + temp = MCP3422_PGA_1; > + break; > + case 2: > + temp = MCP3422_PGA_2; > + break; > + case 4: > + temp = MCP3422_PGA_4; > + break; > + case 8: > + temp = MCP3422_PGA_8; > + break; > + default: > + return -EINVAL; > + } > + > + adc->pga[req_channel] = temp; > + > + config &= ~MCP3422_CHANNEL_MASK; > + config |= MCP3422_CHANNEL_VALUE(req_channel); > + config &= ~MCP3422_PGA_MASK; > + config |= MCP3422_PGA_VALUE(adc->pga[req_channel]); update_config can return an error. return mcp3422_update_config(adc, config); will do the job. Same is true elsewhere so fix them all! > + mcp3422_update_config(adc, config); > + return 0; > + > + case IIO_CHAN_INFO_SAMP_FREQ: > + switch (val1) { > + case 240: > + temp = MCP3422_SRATE_240; > + break; > + case 60: > + temp = MCP3422_SRATE_60; > + break; > + case 15: > + temp = MCP3422_SRATE_15; > + break; > + case 3: > + temp = MCP3422_SRATE_3; > + break; > + default: > + return -EINVAL; > + } > + > + config &= ~MCP3422_CHANNEL_MASK; > + config |= MCP3422_CHANNEL_VALUE(req_channel); > + config &= ~MCP3422_SRATE_MASK; > + config |= MCP3422_SAMPLE_RATE_VALUE(temp); > + > + mcp3422_update_config(adc, config); > + return 0; > + default: > + break; > + } > + > + return -EINVAL; > +} > + > +static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("240 60 15 3"); > +static IIO_CONST_ATTR(in_voltage_scale_available, "1 2 4 8"); > + > +static struct attribute *mcp3422_attributes[] = { > + &iio_const_attr_sampling_frequency_available.dev_attr.attr, > + &iio_const_attr_in_voltage_scale_available.dev_attr.attr, > + NULL, > +}; > + > +static const struct attribute_group mcp3422_attribute_group = { > + .attrs = mcp3422_attributes, > +}; > + > +static const struct iio_chan_spec mcp3422_channels[] = { > + MCP3422_CHAN(0), > + MCP3422_CHAN(1), > +}; > + > +static const struct iio_chan_spec mcp3424_channels[] = { > + MCP3422_CHAN(0), > + MCP3422_CHAN(1), > + MCP3422_CHAN(2), > + MCP3422_CHAN(3), > +}; > + > +static const struct iio_info mcp3422_info = { > + .read_raw = mcp3422_read_raw, > + .write_raw = mcp3422_write_raw, > + .attrs = &mcp3422_attribute_group, > + .driver_module = THIS_MODULE, > +}; > + > +static int mcp3422_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + struct iio_dev *indio_dev; > + struct mcp3422 *adc; > + int err; > + u8 config; > + > + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) > + return -ENODEV; > + > + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*adc)); > + if (!indio_dev) > + return -ENOMEM; > + > + adc = iio_priv(indio_dev); > + adc->i2c = client; > + > + mutex_init(&adc->lock); > + > + indio_dev->dev.parent = &client->dev; > + indio_dev->name = dev_name(&client->dev); > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->info = &mcp3422_info; > + > + switch ((unsigned int)(id->driver_data)) { > + case 2: > + case 3: > + indio_dev->channels = mcp3422_channels; > + indio_dev->num_channels = ARRAY_SIZE(mcp3422_channels); > + break; > + case 4: > + indio_dev->channels = mcp3424_channels; > + indio_dev->num_channels = ARRAY_SIZE(mcp3424_channels); > + break; > + } > + > + /* meaningful default configuration */ > + config = (MCP3422_CONT_SAMPLING > + | MCP3422_CHANNEL_VALUE(1) > + | MCP3422_PGA_VALUE(MCP3422_PGA_1) > + | MCP3422_SAMPLE_RATE_VALUE(MCP3422_SRATE_240)); > + mcp3422_update_config(adc, config); > + > + err = iio_device_register(indio_dev); > + if (err < 0) > + return err; > + > + i2c_set_clientdata(client, indio_dev); > + > + return 0; > +} > + > +static int mcp3422_remove(struct i2c_client *client) > +{ > + struct iio_dev *iio = i2c_get_clientdata(client); > + > + iio_device_unregister(iio); You are using devm_iio_device_alloc so the allocation is managed and it will be freed when the i2c device is. Hence you really don't want to have this iio_device_free call (as then you'll have a double free). Then as you'll only have one use of the struct iio_dev I'd squish the line above to: iio_device_unregister(i2c_get_clientdata(client)); > + iio_device_free(iio); > + > + return 0; > +} > + > +static const struct i2c_device_id mcp3422_id[] = { > + { "mcp3422", 2 }, > + { "mcp3423", 3 }, > + { "mcp3424", 4 }, > + { } > +}; > +MODULE_DEVICE_TABLE(i2c, mcp3422_id); > + > +#ifdef CONFIG_OF > +static const struct of_device_id mcp3422_of_match[] = { > + { .compatible = "mcp3422" }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, mcp3422_of_match); > +#endif > + > +static struct i2c_driver mcp3422_driver = { > + .driver = { > + .name = "mcp3422", > + .owner = THIS_MODULE, > + .of_match_table = of_match_ptr(mcp3422_of_match), > + }, > + .probe = mcp3422_probe, > + .remove = mcp3422_remove, > + .id_table = mcp3422_id, > +}; > +module_i2c_driver(mcp3422_driver); > + > +MODULE_AUTHOR("Angelo Compagnucci <angelo.compagnucci@xxxxxxxxx>"); > +MODULE_DESCRIPTION("Microchip mcp3422/3/4 driver"); > +MODULE_LICENSE("GPL v2"); > -- 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
