diff options
author | Philippe Reynes <tremyfr@yahoo.fr> | 2014-06-14 22:27:00 (GMT) |
---|---|---|
committer | Jonathan Cameron <jic23@kernel.org> | 2014-06-28 08:54:14 (GMT) |
commit | fc167f62483325aea9137e70e6773fe7ad1ca2ac (patch) | |
tree | 767e25d7c2937a1747c02c91fc2599f513e202f6 /drivers/iio/adc | |
parent | b97855354aaacd65d68805bce38af4af1ef703f9 (diff) | |
download | linux-fc167f62483325aea9137e70e6773fe7ad1ca2ac.tar.xz |
iio: add support of the max1027
This driver add partial support of the
maxim 1027/1029/1031. Differential mode is not
supported.
It was tested on armadeus apf27 board.
Signed-off-by: Philippe Reynes <tremyfr@yahoo.fr>
Reviewed-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'drivers/iio/adc')
-rw-r--r-- | drivers/iio/adc/Kconfig | 9 | ||||
-rw-r--r-- | drivers/iio/adc/Makefile | 1 | ||||
-rw-r--r-- | drivers/iio/adc/max1027.c | 521 |
3 files changed, 531 insertions, 0 deletions
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index ee9d85e..de6d2f4 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -131,6 +131,15 @@ config LP8788_ADC help Say yes here to build support for TI LP8788 ADC. +config MAX1027 + tristate "Maxim max1027 ADC driver" + depends on SPI + select IIO_BUFFER + select IIO_TRIGGERED_BUFFER + help + Say yes here to build support for Maxim SPI ADC models + max1027, max1029 and max1031. + config MAX1363 tristate "Maxim max1363 ADC driver" depends on I2C diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index 9d60f2d..38cf5c3 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -15,6 +15,7 @@ obj-$(CONFIG_AD799X) += ad799x.o obj-$(CONFIG_AT91_ADC) += at91_adc.o obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o +obj-$(CONFIG_MAX1027) += max1027.o obj-$(CONFIG_MAX1363) += max1363.o obj-$(CONFIG_MCP320X) += mcp320x.o obj-$(CONFIG_MCP3422) += mcp3422.o diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c new file mode 100644 index 0000000..87ee1c7 --- /dev/null +++ b/drivers/iio/adc/max1027.c @@ -0,0 +1,521 @@ + /* + * iio/adc/max1027.c + * Copyright (C) 2014 Philippe Reynes + * + * based on linux/drivers/iio/ad7923.c + * Copyright 2011 Analog Devices Inc (from AD7923 Driver) + * Copyright 2012 CS Systemes d'Information + * + * 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. + * + * max1027.c + * + * Partial support for max1027 and similar chips. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/spi/spi.h> +#include <linux/delay.h> + +#include <linux/iio/iio.h> +#include <linux/iio/buffer.h> +#include <linux/iio/trigger.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> + +#define MAX1027_CONV_REG BIT(7) +#define MAX1027_SETUP_REG BIT(6) +#define MAX1027_AVG_REG BIT(5) +#define MAX1027_RST_REG BIT(4) + +/* conversion register */ +#define MAX1027_TEMP BIT(0) +#define MAX1027_SCAN_0_N (0x00 << 1) +#define MAX1027_SCAN_N_M (0x01 << 1) +#define MAX1027_SCAN_N (0x02 << 1) +#define MAX1027_NOSCAN (0x03 << 1) +#define MAX1027_CHAN(n) ((n) << 3) + +/* setup register */ +#define MAX1027_UNIPOLAR 0x02 +#define MAX1027_BIPOLAR 0x03 +#define MAX1027_REF_MODE0 (0x00 << 2) +#define MAX1027_REF_MODE1 (0x01 << 2) +#define MAX1027_REF_MODE2 (0x02 << 2) +#define MAX1027_REF_MODE3 (0x03 << 2) +#define MAX1027_CKS_MODE0 (0x00 << 4) +#define MAX1027_CKS_MODE1 (0x01 << 4) +#define MAX1027_CKS_MODE2 (0x02 << 4) +#define MAX1027_CKS_MODE3 (0x03 << 4) + +/* averaging register */ +#define MAX1027_NSCAN_4 0x00 +#define MAX1027_NSCAN_8 0x01 +#define MAX1027_NSCAN_12 0x02 +#define MAX1027_NSCAN_16 0x03 +#define MAX1027_NAVG_4 (0x00 << 2) +#define MAX1027_NAVG_8 (0x01 << 2) +#define MAX1027_NAVG_16 (0x02 << 2) +#define MAX1027_NAVG_32 (0x03 << 2) +#define MAX1027_AVG_EN BIT(4) + +enum max1027_id { + max1027, + max1029, + max1031, +}; + +static const struct spi_device_id max1027_id[] = { + {"max1027", max1027}, + {"max1029", max1029}, + {"max1031", max1031}, + {} +}; +MODULE_DEVICE_TABLE(spi, max1027_id); + +#ifdef CONFIG_OF +static const struct of_device_id max1027_adc_dt_ids[] = { + { .compatible = "maxim,max1027" }, + { .compatible = "maxim,max1029" }, + { .compatible = "maxim,max1031" }, + {}, +}; +MODULE_DEVICE_TABLE(of, max1027_adc_dt_ids); +#endif + +#define MAX1027_V_CHAN(index) \ + { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = index, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ + .scan_index = index + 1, \ + .scan_type = { \ + .sign = 'u', \ + .realbits = 10, \ + .storagebits = 16, \ + .shift = 2, \ + .endianness = IIO_BE, \ + }, \ + } + +#define MAX1027_T_CHAN \ + { \ + .type = IIO_TEMP, \ + .channel = 0, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ + .scan_index = 0, \ + .scan_type = { \ + .sign = 'u', \ + .realbits = 12, \ + .storagebits = 16, \ + .endianness = IIO_BE, \ + }, \ + } + +static const struct iio_chan_spec max1027_channels[] = { + MAX1027_T_CHAN, + MAX1027_V_CHAN(0), + MAX1027_V_CHAN(1), + MAX1027_V_CHAN(2), + MAX1027_V_CHAN(3), + MAX1027_V_CHAN(4), + MAX1027_V_CHAN(5), + MAX1027_V_CHAN(6), + MAX1027_V_CHAN(7) +}; + +static const struct iio_chan_spec max1029_channels[] = { + MAX1027_T_CHAN, + MAX1027_V_CHAN(0), + MAX1027_V_CHAN(1), + MAX1027_V_CHAN(2), + MAX1027_V_CHAN(3), + MAX1027_V_CHAN(4), + MAX1027_V_CHAN(5), + MAX1027_V_CHAN(6), + MAX1027_V_CHAN(7), + MAX1027_V_CHAN(8), + MAX1027_V_CHAN(9), + MAX1027_V_CHAN(10), + MAX1027_V_CHAN(11) +}; + +static const struct iio_chan_spec max1031_channels[] = { + MAX1027_T_CHAN, + MAX1027_V_CHAN(0), + MAX1027_V_CHAN(1), + MAX1027_V_CHAN(2), + MAX1027_V_CHAN(3), + MAX1027_V_CHAN(4), + MAX1027_V_CHAN(5), + MAX1027_V_CHAN(6), + MAX1027_V_CHAN(7), + MAX1027_V_CHAN(8), + MAX1027_V_CHAN(9), + MAX1027_V_CHAN(10), + MAX1027_V_CHAN(11), + MAX1027_V_CHAN(12), + MAX1027_V_CHAN(13), + MAX1027_V_CHAN(14), + MAX1027_V_CHAN(15) +}; + +static const unsigned long max1027_available_scan_masks[] = { + 0x000001ff, + 0x00000000, +}; + +static const unsigned long max1029_available_scan_masks[] = { + 0x00001fff, + 0x00000000, +}; + +static const unsigned long max1031_available_scan_masks[] = { + 0x0001ffff, + 0x00000000, +}; + +struct max1027_chip_info { + const struct iio_chan_spec *channels; + unsigned int num_channels; + const unsigned long *available_scan_masks; +}; + +static const struct max1027_chip_info max1027_chip_info_tbl[] = { + [max1027] = { + .channels = max1027_channels, + .num_channels = ARRAY_SIZE(max1027_channels), + .available_scan_masks = max1027_available_scan_masks, + }, + [max1029] = { + .channels = max1029_channels, + .num_channels = ARRAY_SIZE(max1029_channels), + .available_scan_masks = max1029_available_scan_masks, + }, + [max1031] = { + .channels = max1031_channels, + .num_channels = ARRAY_SIZE(max1031_channels), + .available_scan_masks = max1031_available_scan_masks, + }, +}; + +struct max1027_state { + const struct max1027_chip_info *info; + struct spi_device *spi; + struct iio_trigger *trig; + __be16 *buffer; + struct mutex lock; + + u8 reg ____cacheline_aligned; +}; + +static int max1027_read_single_value(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val) +{ + int ret; + struct max1027_state *st = iio_priv(indio_dev); + + if (iio_buffer_enabled(indio_dev)) { + dev_warn(&indio_dev->dev, "trigger mode already enabled"); + return -EBUSY; + } + + /* Start acquisition on conversion register write */ + st->reg = MAX1027_SETUP_REG | MAX1027_REF_MODE2 | MAX1027_CKS_MODE2; + ret = spi_write(st->spi, &st->reg, 1); + if (ret < 0) { + dev_err(&indio_dev->dev, + "Failed to configure setup register\n"); + return ret; + } + + /* Configure conversion register with the requested chan */ + st->reg = MAX1027_CONV_REG | MAX1027_CHAN(chan->channel) | + MAX1027_NOSCAN | !!(chan->type == IIO_TEMP); + ret = spi_write(st->spi, &st->reg, 1); + if (ret < 0) { + dev_err(&indio_dev->dev, + "Failed to configure conversion register\n"); + return ret; + } + + /* + * For an unknown reason, when we use the mode "10" (write + * conversion register), the interrupt doesn't occur every time. + * So we just wait 1 ms. + */ + mdelay(1); + + /* Read result */ + ret = spi_read(st->spi, st->buffer, (chan->type == IIO_TEMP) ? 4 : 2); + if (ret < 0) + return ret; + + *val = be16_to_cpu(st->buffer[0]); + + return IIO_VAL_INT; +} + +static int max1027_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + int ret = 0; + struct max1027_state *st = iio_priv(indio_dev); + + mutex_lock(&st->lock); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = max1027_read_single_value(indio_dev, chan, val); + break; + case IIO_CHAN_INFO_SCALE: + switch (chan->type) { + case IIO_TEMP: + *val = 1; + *val2 = 8; + ret = IIO_VAL_FRACTIONAL; + break; + case IIO_VOLTAGE: + *val = 2500; + *val2 = 10; + ret = IIO_VAL_FRACTIONAL_LOG2; + break; + default: + ret = -EINVAL; + break; + } + break; + default: + ret = -EINVAL; + break; + } + + mutex_unlock(&st->lock); + + return ret; +} + +static int max1027_debugfs_reg_access(struct iio_dev *indio_dev, + unsigned reg, unsigned writeval, + unsigned *readval) +{ + struct max1027_state *st = iio_priv(indio_dev); + u8 *val = (u8 *)st->buffer; + + if (readval != NULL) + return -EINVAL; + + *val = (u8)writeval; + return spi_write(st->spi, val, 1); +} + +static int max1027_validate_trigger(struct iio_dev *indio_dev, + struct iio_trigger *trig) +{ + struct max1027_state *st = iio_priv(indio_dev); + + if (st->trig != trig) + return -EINVAL; + + return 0; +} + +static int max1027_set_trigger_state(struct iio_trigger *trig, bool state) +{ + struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); + struct max1027_state *st = iio_priv(indio_dev); + int ret; + + if (state) { + /* Start acquisition on cnvst */ + st->reg = MAX1027_SETUP_REG | MAX1027_CKS_MODE0 | + MAX1027_REF_MODE2; + ret = spi_write(st->spi, &st->reg, 1); + if (ret < 0) + return ret; + + /* Scan from 0 to max */ + st->reg = MAX1027_CONV_REG | MAX1027_CHAN(0) | + MAX1027_SCAN_N_M | MAX1027_TEMP; + ret = spi_write(st->spi, &st->reg, 1); + if (ret < 0) + return ret; + } else { + /* Start acquisition on conversion register write */ + st->reg = MAX1027_SETUP_REG | MAX1027_CKS_MODE2 | + MAX1027_REF_MODE2; + ret = spi_write(st->spi, &st->reg, 1); + if (ret < 0) + return ret; + } + + return 0; +} + +static int max1027_validate_device(struct iio_trigger *trig, + struct iio_dev *indio_dev) +{ + struct iio_dev *indio = iio_trigger_get_drvdata(trig); + + if (indio != indio_dev) + return -EINVAL; + + return 0; +} + +static irqreturn_t max1027_trigger_handler(int irq, void *private) +{ + struct iio_poll_func *pf = (struct iio_poll_func *)private; + struct iio_dev *indio_dev = pf->indio_dev; + struct max1027_state *st = iio_priv(indio_dev); + + pr_debug("%s(irq=%d, private=0x%p)\n", __func__, irq, private); + + /* fill buffer with all channel */ + spi_read(st->spi, st->buffer, indio_dev->masklength * 2); + + iio_push_to_buffers(indio_dev, st->buffer); + + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + +static const struct iio_trigger_ops max1027_trigger_ops = { + .owner = THIS_MODULE, + .validate_device = &max1027_validate_device, + .set_trigger_state = &max1027_set_trigger_state, +}; + +static const struct iio_info max1027_info = { + .driver_module = THIS_MODULE, + .read_raw = &max1027_read_raw, + .validate_trigger = &max1027_validate_trigger, + .debugfs_reg_access = &max1027_debugfs_reg_access, +}; + +static int max1027_probe(struct spi_device *spi) +{ + int ret; + struct iio_dev *indio_dev; + struct max1027_state *st; + + pr_debug("%s: probe(spi = 0x%p)\n", __func__, spi); + + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); + if (indio_dev == NULL) { + pr_err("Can't allocate iio device\n"); + return -ENOMEM; + } + + spi_set_drvdata(spi, indio_dev); + + st = iio_priv(indio_dev); + st->spi = spi; + st->info = &max1027_chip_info_tbl[spi_get_device_id(spi)->driver_data]; + + mutex_init(&st->lock); + + indio_dev->name = spi_get_device_id(spi)->name; + indio_dev->dev.parent = &spi->dev; + indio_dev->info = &max1027_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = st->info->channels; + indio_dev->num_channels = st->info->num_channels; + indio_dev->available_scan_masks = st->info->available_scan_masks; + + st->buffer = devm_kmalloc(&indio_dev->dev, + indio_dev->num_channels * 2, + GFP_KERNEL); + if (st->buffer == NULL) { + dev_err(&indio_dev->dev, "Can't allocate bufffer\n"); + return -ENOMEM; + } + + ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time, + &max1027_trigger_handler, NULL); + if (ret < 0) { + dev_err(&indio_dev->dev, "Failed to setup buffer\n"); + return ret; + } + + st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-trigger", + indio_dev->name); + if (st->trig == NULL) { + ret = -ENOMEM; + dev_err(&indio_dev->dev, "Failed to allocate iio trigger\n"); + goto fail_trigger_alloc; + } + + st->trig->ops = &max1027_trigger_ops; + st->trig->dev.parent = &spi->dev; + iio_trigger_set_drvdata(st->trig, indio_dev); + iio_trigger_register(st->trig); + + ret = devm_request_threaded_irq(&spi->dev, spi->irq, + iio_trigger_generic_data_rdy_poll, + NULL, + IRQF_TRIGGER_FALLING, + spi->dev.driver->name, st->trig); + if (ret < 0) { + dev_err(&indio_dev->dev, "Failed to allocate IRQ.\n"); + goto fail_dev_register; + } + + /* Disable averaging */ + st->reg = MAX1027_AVG_REG; + ret = spi_write(st->spi, &st->reg, 1); + if (ret < 0) { + dev_err(&indio_dev->dev, "Failed to configure averaging register\n"); + goto fail_dev_register; + } + + ret = iio_device_register(indio_dev); + if (ret < 0) { + dev_err(&indio_dev->dev, "Failed to register iio device\n"); + goto fail_dev_register; + } + + return 0; + +fail_dev_register: +fail_trigger_alloc: + iio_triggered_buffer_cleanup(indio_dev); + + return ret; +} + +static int max1027_remove(struct spi_device *spi) +{ + struct iio_dev *indio_dev = spi_get_drvdata(spi); + + pr_debug("%s: remove(spi = 0x%p)\n", __func__, spi); + + iio_device_unregister(indio_dev); + iio_triggered_buffer_cleanup(indio_dev); + + return 0; +} + +static struct spi_driver max1027_driver = { + .driver = { + .name = "max1027", + .owner = THIS_MODULE, + }, + .probe = max1027_probe, + .remove = max1027_remove, + .id_table = max1027_id, +}; +module_spi_driver(max1027_driver); + +MODULE_AUTHOR("Philippe Reynes <tremyfr@yahoo.fr>"); +MODULE_DESCRIPTION("MAX1027/MAX1029/MAX1031 ADC"); +MODULE_LICENSE("GPL v2"); |