diff options
Diffstat (limited to 'drivers/iio/adc/mcp3422.c')
| -rw-r--r-- | drivers/iio/adc/mcp3422.c | 410 |
1 files changed, 0 insertions, 410 deletions
diff --git a/drivers/iio/adc/mcp3422.c b/drivers/iio/adc/mcp3422.c deleted file mode 100644 index c8c1baa..0000000 --- a/drivers/iio/adc/mcp3422.c +++ /dev/null @@ -1,410 +0,0 @@ -/* - * mcp3422.c - driver for the Microchip mcp3422/3/4 chip family - * - * Copyright (C) 2013, Angelo Compagnucci - * Author: Angelo Compagnucci <angelo.compagnucci@gmail.com> - * - * 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/of.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}; - -/* - * scales calculated as: - * rates_to_lsb[sample_rate] / (1 << pga); - * pga is 1 for 0, 2 - */ - -static const int mcp3422_scales[4][4] = { - { 1000000, 250000, 62500, 15625 }, - { 500000 , 125000, 31250, 7812 }, - { 250000 , 62500 , 15625, 3906 }, - { 125000 , 31250 , 7812 , 1953 } }; - -/* Constant msleep times for data acquisitions */ -static const int mcp3422_read_times[4] = { - [MCP3422_SRATE_240] = 1000 / 240, - [MCP3422_SRATE_60] = 1000 / 60, - [MCP3422_SRATE_15] = 1000 / 15, - [MCP3422_SRATE_3] = 1000 / 3 }; - -/* sample rates to integer conversion table */ -static const int mcp3422_sample_rates[4] = { - [MCP3422_SRATE_240] = 240, - [MCP3422_SRATE_60] = 60, - [MCP3422_SRATE_15] = 15, - [MCP3422_SRATE_3] = 3 }; - -/* sample rates to sign extension table */ -static const int mcp3422_sign_extend[4] = { - [MCP3422_SRATE_240] = 11, - [MCP3422_SRATE_60] = 13, - [MCP3422_SRATE_15] = 15, - [MCP3422_SRATE_3] = 17 }; - -/* 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; - ret = 0; - } - - 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); - temp = buf[0] << 8 | buf[1]; - *config = buf[2]; - } - - *value = sign_extend32(temp, mcp3422_sign_extend[sample_rate]); - - return ret; -} - -static int mcp3422_read_channel(struct mcp3422 *adc, - struct iio_chan_spec const *channel, int *value) -{ - int ret; - u8 config; - 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]); - ret = mcp3422_update_config(adc, config); - if (ret < 0) - return ret; - msleep(mcp3422_read_times[MCP3422_SAMPLE_RATE(adc->config)]); - } - - 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; - - u8 sample_rate = MCP3422_SAMPLE_RATE(adc->config); - u8 pga = MCP3422_PGA(adc->config); - - switch (mask) { - case IIO_CHAN_INFO_RAW: - err = mcp3422_read_channel(adc, channel, val1); - if (err < 0) - return -EINVAL; - return IIO_VAL_INT; - - case IIO_CHAN_INFO_SCALE: - - *val1 = 0; - *val2 = mcp3422_scales[sample_rate][pga]; - return IIO_VAL_INT_PLUS_NANO; - - case IIO_CHAN_INFO_SAMP_FREQ: - *val1 = mcp3422_sample_rates[MCP3422_SAMPLE_RATE(adc->config)]; - 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; - u8 sample_rate = MCP3422_SAMPLE_RATE(config); - u8 i; - - switch (mask) { - case IIO_CHAN_INFO_SCALE: - if (val1 != 0) - return -EINVAL; - - for (i = 0; i < ARRAY_SIZE(mcp3422_scales[0]); i++) { - if (val2 == mcp3422_scales[sample_rate][i]) { - adc->pga[req_channel] = i; - - config &= ~MCP3422_CHANNEL_MASK; - config |= MCP3422_CHANNEL_VALUE(req_channel); - config &= ~MCP3422_PGA_MASK; - config |= MCP3422_PGA_VALUE(adc->pga[req_channel]); - - return mcp3422_update_config(adc, config); - } - } - return -EINVAL; - - 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); - - return mcp3422_update_config(adc, config); - - default: - break; - } - - return -EINVAL; -} - -static int mcp3422_write_raw_get_fmt(struct iio_dev *indio_dev, - struct iio_chan_spec const *chan, long mask) -{ - switch (mask) { - case IIO_CHAN_INFO_SCALE: - return IIO_VAL_INT_PLUS_NANO; - case IIO_CHAN_INFO_SAMP_FREQ: - return IIO_VAL_INT_PLUS_MICRO; - default: - return -EINVAL; - } -} - -static ssize_t mcp3422_show_scales(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct mcp3422 *adc = iio_priv(dev_to_iio_dev(dev)); - u8 sample_rate = MCP3422_SAMPLE_RATE(adc->config); - - return sprintf(buf, "0.%09u 0.%09u 0.%09u 0.%09u\n", - mcp3422_scales[sample_rate][0], - mcp3422_scales[sample_rate][1], - mcp3422_scales[sample_rate][2], - mcp3422_scales[sample_rate][3]); -} - -static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("240 60 15 3"); -static IIO_DEVICE_ATTR(in_voltage_scale_available, S_IRUGO, - mcp3422_show_scales, NULL, 0); - -static struct attribute *mcp3422_attributes[] = { - &iio_const_attr_sampling_frequency_available.dev_attr.attr, - &iio_dev_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, - .write_raw_get_fmt = mcp3422_write_raw_get_fmt, - .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) -{ - iio_device_unregister(i2c_get_clientdata(client)); - 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@gmail.com>"); -MODULE_DESCRIPTION("Microchip mcp3422/3/4 driver"); -MODULE_LICENSE("GPL v2"); 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