Add new driver for Texas Instruments ADS1118 and and ADS1018. This driver works with ADS1018, because of code borrowed from asd1015, which is similar, but I can only test ADS1118 Signed-off-by: Joshua Clayton <stillcompiling@xxxxxxxxx> --- drivers/hwmon/Kconfig | 11 ++ drivers/hwmon/Makefile | 1 + drivers/hwmon/ads1118.c | 516 ++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 528 insertions(+) create mode 100644 drivers/hwmon/ads1118.c diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index ff94007..cadde38 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -1459,6 +1459,17 @@ config SENSORS_ADS1015 This driver can also be built as a module. If so, the module will be called ads1015. +config SENSORS_ADS1118 + tristate "Texas Instruments ADS1018/ADS1118" + depends on SPI + help + If you say yes here you get support for Texas Instruments + ADS1118 16-bit 4-input ADC device and temperature sensor, + and the 12-bit ADS1018. + + This driver can also be built as a module. If so, the module + will be called ads1118. + config SENSORS_ADS7828 tristate "Texas Instruments ADS7828 and compatibles" depends on I2C diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index 2ef5b7c..a3b4b2e 100644 --- a/drivers/hwmon/Makefile +++ b/drivers/hwmon/Makefile @@ -34,6 +34,7 @@ obj-$(CONFIG_SENSORS_ADM1029) += adm1029.o obj-$(CONFIG_SENSORS_ADM1031) += adm1031.o obj-$(CONFIG_SENSORS_ADM9240) += adm9240.o obj-$(CONFIG_SENSORS_ADS1015) += ads1015.o +obj-$(CONFIG_SENSORS_ADS1118) += ads1118.o obj-$(CONFIG_SENSORS_ADS7828) += ads7828.o obj-$(CONFIG_SENSORS_ADS7871) += ads7871.o obj-$(CONFIG_SENSORS_ADT7X10) += adt7x10.o diff --git a/drivers/hwmon/ads1118.c b/drivers/hwmon/ads1118.c new file mode 100644 index 0000000..65ee337 --- /dev/null +++ b/drivers/hwmon/ads1118.c @@ -0,0 +1,516 @@ +/* + * ads1118.c - hwmon driver for Texas Instruments ADS1118 16-bit 4-input ADC + * / temperature sensor, and Texas Instruments ADS1018, a faster, 12-bit + * chip of the same family. + * + * Author: Joshua Clayton + * + * Loosely based on ads1015.c by Dirk Eibach and others + * + * 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/module.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/delay.h> +#include <linux/hwmon.h> +#include <linux/hwmon-sysfs.h> +#include <linux/err.h> +#include <linux/mutex.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/spi/spi.h> + +struct ads_table { + unsigned int rates[8]; + unsigned int divisor; +}; + +struct ads_channel { + unsigned int delay_ms; + int pga; + u16 cfg; + bool enabled; +}; + +/* PGA fullscale voltages in microvolts */ +static const unsigned int fullscale_table[8] = { + 6144000, 4096000, 2048000, 1024000, 512000, 256000, 256000, 256000 }; + +static const struct ads_table ads1018_table = { + .rates = {128, 250, 490, 920, 1600, 2400, 3300, 3300}, + .divisor = 0x7ff0, +}; + +static const struct ads_table ads1118_table = { + .rates = {8, 16, 32, 64, 128, 250, 475, 860}, + .divisor = 0x7fff, +}; + +#define ADS1118_NUM_CHANS 5 +#define ADS1118_TEMP_CHAN 4 + +struct ads1118 { + struct device *hwmon_dev; + struct device *dev; + struct mutex update_lock; /* mutex protect updates */ + struct ads_channel channel_data[ADS1118_NUM_CHANS]; + const struct ads_table *ref; +}; + +/* + * NOTE: the bit offsets in the datasheet are 16 bit big + * endian. I've swapped upper and lower bytes in the defines + * so no twiddling is needed when sending the cfg to the device. + */ +#define ADS1118_MODE 0 /* single shot mode */ +#define ADS1118_PGA 1 /* programmmed gain */ +#define ADS1118_MUX 4 /* input channel */ +#define ADS1118_SS 7 /* start a conversion */ +#define ADS1118_NOP 8 /* validation pattern */ +#define ADS1118_PULL_UP 11 /* pullup resistor on MISO */ +#define ADS1118_TS_MODE 12 /* temperature sensor mode */ +#define ADS1118_DR 13 /* data rate table index */ + +#define ADS1118_ADC_CFG (BIT(ADS1118_MODE) | BIT(ADS1118_SS) | \ + (0x3 << ADS1118_NOP) | BIT(ADS1118_PULL_UP)) +#define ADS1118_TEMP_CFG (ADS1118_ADC_CFG | BIT(ADS1118_TS_MODE)) + +/* MUX values for AINN (second input or ground) */ +#define ADS1118_MUX_AINN1 0 +#define ADS1118_MUX_AINN3 1 +#define ADS1118_MUX_AINN_GND 4 + +#define ADS1118_DEFAULT_PGA 0 +#define ADS1118_DEFAULT_DR 7 + +static inline void ads1118_set_cfg(u16 *cfg, u16 value, int offset) +{ + *cfg &= ~(0x07 << offset); + *cfg |= ((value & 0x07) << offset); +} + +static int ads1118_channel_set_pga(struct ads_channel *chan, u32 fullscale) +{ + int i; + + for (i = 7; i >= 0; --i) + if (fullscale_table[i] == fullscale) + break; + + if (i < 0) + return -EINVAL; + + chan->pga = fullscale / 1000; + ads1118_set_cfg(&chan->cfg, i, ADS1118_PGA); + + return 0; +} + +static int ads1118_chan_set_mux(struct ads_channel *chan, u16 in1, u16 in2) +{ + switch (in1) { + case 0: + if (in2 == ADS1118_MUX_AINN1) + break; + case 1: + case 2: + if (in2 == ADS1118_MUX_AINN3) + break; + case 3: + if (in2 == ADS1118_MUX_AINN_GND) + break; + default: + return -EINVAL; + } + + ads1118_set_cfg(&chan->cfg, in1 + in2, ADS1118_MUX); + + return 0; +} + +static int ads1118_chan_set_rate(struct ads1118 *ads, + struct ads_channel *chan, u32 rate) +{ + int i; + + for (i = 7; i >= 0; --i) + if (ads->ref->rates[i] == rate) + break; + + if (i < 0) + return -EINVAL; + + chan->delay_ms = DIV_ROUND_UP(1000, rate); + ads1118_set_cfg(&chan->cfg, i, ADS1118_DR); + + return 0; +} + +static int ads1118_read_adc(struct ads1118 *ads, struct ads_channel *chan, + s16 *value) +{ + int ret; + u16 buf; + struct spi_device *spi = to_spi_device(ads->dev); + + mutex_lock(&ads->update_lock); + + ret = spi_write(spi, &chan->cfg, sizeof(chan->cfg)); + if (ret < 0) + goto err_unlock; + + /* wait until conversion finished */ + msleep(chan->delay_ms); + + ret = spi_read(spi, &buf, sizeof(buf)); + if (ret) + dev_info(&spi->dev, "error reading: %d\n", ret); + + *value = (s16)be16_to_cpu(buf); + +err_unlock: + mutex_unlock(&ads->update_lock); + return ret; +} + +static ssize_t show_in(struct device *dev, struct device_attribute *da, + char *buf) +{ + struct sensor_device_attribute *attr = to_sensor_dev_attr(da); + struct ads1118 *ads = dev_get_drvdata(dev); + struct ads_channel *chan = &ads->channel_data[attr->index]; + s16 read_value; + int microvolts; + int ret; + + ret = ads1118_read_adc(ads, chan, &read_value); + if (ret < 0) + return ret; + + microvolts = DIV_ROUND_CLOSEST(read_value * chan->pga, + ads->ref->divisor); + + return sprintf(buf, "%d\n", microvolts); +} + +static ssize_t show_temp(struct device *dev, struct device_attribute *da, + char *buf) +{ + struct sensor_device_attribute *attr = to_sensor_dev_attr(da); + struct ads1118 *ads = dev_get_drvdata(dev); + struct ads_channel *chan = &ads->channel_data[attr->index]; + s16 read_value; + int ret; + + ret = ads1118_read_adc(ads, chan, &read_value); + if (ret < 0) + return ret; + + /* + * The ads1118 datasheet indicates 32nds of degree steps, but + * 14 bits left justified means a divisor of 128. + */ + return sprintf(buf, "%d\n", (((int)read_value) * 1000) >> 7); +} + +static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, show_in, NULL, 0); +static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, show_in, NULL, 1); +static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, show_in, NULL, 2); +static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, show_in, NULL, 3); +static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, + ADS1118_TEMP_CHAN); + +static struct attribute *ads1118_attributes[] = { + &sensor_dev_attr_in0_input.dev_attr.attr, + &sensor_dev_attr_in1_input.dev_attr.attr, + &sensor_dev_attr_in2_input.dev_attr.attr, + &sensor_dev_attr_in3_input.dev_attr.attr, + + &sensor_dev_attr_temp1_input.dev_attr.attr, + NULL +}; + +static umode_t ads1118_attrs_visible(struct kobject *kobj, + struct attribute *attr, int n) +{ + struct device *dev = container_of(kobj, struct device, kobj); + struct ads1118 *ads = dev_get_drvdata(dev); + + if (ads->channel_data[n].enabled) + return attr->mode; + + return 0; +} + +static const struct attribute_group ads1118_attr_group = { + .attrs = ads1118_attributes, + .is_visible = ads1118_attrs_visible, +}; + +static const struct attribute_group *groups[] = { + &ads1118_attr_group, + NULL +}; + +#ifdef CONFIG_OF +static int ads1118_of_get_chan(struct device *dev, struct device_node *node) +{ + u32 chan_i; + + if (!of_device_is_available(node)) + return -EINVAL; + + if (of_property_read_u32(node, "reg", &chan_i)) { + dev_err(dev, "reg value missing in %s\n", node->full_name); + return -EINVAL; + } + + if (chan_i >= ADS1118_TEMP_CHAN) { + dev_err(dev, "reg value %d out of range in %s\n", + chan_i, node->full_name); + return -EINVAL; + } + + return (int)chan_i; +} + +static int ads1118_of_get_chan_pga(struct device *dev, + struct device_node *node, + struct ads_channel *chan) +{ + int ret; + u32 fullscale; + + ret = of_property_read_u32(node, "ti,fullscale", &fullscale); + if (ret == -EINVAL) { + fullscale = fullscale_table[ADS1118_DEFAULT_PGA]; + } else if (ret) { + dev_err(dev, "bad ti,fullscale on %s: should be u32\n", + node->full_name); + return ret; + } + + ret = ads1118_channel_set_pga(chan, fullscale); + if (ret) + dev_err(dev, "bad ti,fullscale on %s: invalid value\n", + node->full_name); + + return ret; +} + +static int ads1118_of_get_chan_datarate(struct ads1118 *ads, + struct device_node *node, + struct ads_channel *chan) +{ + int ret; + u32 rate; + + ret = of_property_read_u32(node, "ti,datarate", &rate); + if (ret == -EINVAL) { + rate = ads->ref->rates[ADS1118_DEFAULT_DR]; + } else if (ret) { + dev_err(ads->dev, "bad ti,datarate on %s: should be u32\n", + node->full_name); + return ret; + } + + ret = ads1118_chan_set_rate(ads, chan, rate); + if (ret) + dev_err(ads->dev, "bad ti,datarate on %s: invalid value\n", + node->full_name); + + return ret; +} + +static int ads1118_of_get_chan_mux(struct device *dev, + struct device_node *node, + struct ads_channel *chan, + int chan_i) +{ + int ret; + u32 de; + u16 in2; + + ret = of_property_read_u32(node, "ti,differential-endpoint", &de); + if (ret == -EINVAL) { + in2 = ADS1118_MUX_AINN_GND; + goto set_mux; + } else if (ret) { + dev_err(dev, "bad ti,differential-endpoint on %s: should be a u32\n", + node->full_name); + return ret; + } + + switch (de) { + case 1: + in2 = ADS1118_MUX_AINN1; + break; + case 3: + in2 = ADS1118_MUX_AINN3; + break; + default: + dev_err(dev, "bad ti,differential-endpoint %d on %s\n", + de, node->full_name); + return -EINVAL; + } + +set_mux: + ret = ads1118_chan_set_mux(chan, (u16)chan_i, in2); + if (ret) + dev_err(dev, "bad ti,differential-endpoint pair %d, %d on %s\n", + chan_i, de, node->full_name); + + return ret; +} + +static void ads1118_of_cfg_chan(struct ads1118 *ads, struct device_node *node) +{ + int ret; + int chan_i; + struct ads_channel *chan; + + chan_i = ads1118_of_get_chan(ads->dev, node); + if (chan_i < 0) + return; + + chan = &ads->channel_data[chan_i]; + chan->cfg = ADS1118_ADC_CFG; + ret = ads1118_of_get_chan_pga(ads->dev, node, chan); + if (ret) + return; + + ret = ads1118_of_get_chan_datarate(ads, node, chan); + if (ret) + return; + + ret = ads1118_of_get_chan_mux(ads->dev, node, chan, chan_i); + if (ret) + return; + + chan->enabled = true; +} + +static void ads1118_of_get_pullup(struct ads1118 *ads) +{ + int i; + + if (of_find_property(ads->dev->of_node, "ti,pullup-disable", NULL)) + for (i = 0; i < ADS1118_NUM_CHANS; ++i) + ads->channel_data[i].cfg &= ~(BIT(ADS1118_PULL_UP)); +} +#endif + +static void ads1118_temp_chan_enable(struct ads1118 *ads) +{ + struct ads_channel *chan = &ads->channel_data[ADS1118_TEMP_CHAN]; + unsigned int rate = ads->ref->rates[ADS1118_DEFAULT_DR]; + + chan->cfg = ADS1118_TEMP_CFG; + ads1118_chan_set_rate(ads, chan, rate); + chan->enabled = true; +} + +static int ads1118_get_cfg(struct ads1118 *ads) +{ + struct device_node *node; + +#ifndef CONFIG_OF + return -EINVAL; +#else + if (!ads->dev->of_node + || !of_get_next_child(ads->dev->of_node, NULL)) + return -EINVAL; + + if (of_find_property(ads->dev->of_node, "ti,tempsensor", NULL)) + ads1118_temp_chan_enable(ads); + + ads1118_of_get_pullup(ads); + + for_each_child_of_node(ads->dev->of_node, node) { + ads1118_of_cfg_chan(ads, node); + } + + return 0; +#endif +} + +static void ads1118_enable_all(struct ads1118 *ads) +{ + unsigned int i; + unsigned int fullscale = fullscale_table[ADS1118_DEFAULT_PGA]; + unsigned int rate = ads->ref->rates[ADS1118_DEFAULT_DR]; + + ads1118_temp_chan_enable(ads); + + for (i = 0; i < ADS1118_TEMP_CHAN; ++i) { + struct ads_channel *chan = &ads->channel_data[i]; + + chan->cfg = ADS1118_ADC_CFG; + ads1118_channel_set_pga(chan, fullscale); + ads1118_chan_set_rate(ads, chan, rate); + ads1118_chan_set_mux(chan, (u16)i, ADS1118_MUX_AINN_GND); + chan->enabled = true; + } +} + +static const struct of_device_id ads_1x18_ids[] = { + { .compatible = "ti,ads1018", .data = &ads1018_table, }, + { .compatible = "ti,ads1118", .data = &ads1118_table, }, + { /* sentinel */ } +}; + +MODULE_DEVICE_TABLE(of, ads_1x18_ids); + +static int ads1118_probe(struct spi_device *spi) +{ + const struct of_device_id *of_id; + struct ads1118 *ads; + int err; + + ads = devm_kzalloc(&spi->dev, sizeof(struct ads1118), + GFP_KERNEL); + if (!ads) + return -ENOMEM; + + of_id = of_match_device(ads_1x18_ids, &spi->dev); + if (!of_id) + return -EINVAL; + + ads->ref = of_id->data; + ads->dev = &spi->dev; + mutex_init(&ads->update_lock); + err = ads1118_get_cfg(ads); + if (err) + ads1118_enable_all(ads); + + ads->hwmon_dev = + devm_hwmon_device_register_with_groups(ads->dev, "ads11118", + ads, groups); + if (IS_ERR(ads->hwmon_dev)) { + err = PTR_ERR(ads->hwmon_dev); + dev_err(ads->dev, "error initializing hwmon: %d\n", err); + return err; + } + + return 0; +} + +static struct spi_driver ads1118_driver = { + .driver = { + .name = "ads1118", + .of_match_table = ads_1x18_ids, + }, + .probe = ads1118_probe, +}; + +module_spi_driver(ads1118_driver); + +MODULE_AUTHOR("Joshua Clayton <stillcompiling@xxxxxxxxx>"); +MODULE_DESCRIPTION("ADS1118 driver"); +MODULE_LICENSE("GPL"); -- 2.7.4 -- 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