diff options
author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-09-11 04:34:46 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-09-11 04:34:46 -0300 |
commit | 863981e96738983919de841ec669e157e6bdaeb0 (patch) | |
tree | d6d89a12e7eb8017837c057935a2271290907f76 /drivers/iio/dac/ad5592r-base.c | |
parent | 8dec7c70575785729a6a9e6719a955e9c545bcab (diff) |
Linux-libre 4.7.1-gnupck-4.7.1-gnu
Diffstat (limited to 'drivers/iio/dac/ad5592r-base.c')
-rw-r--r-- | drivers/iio/dac/ad5592r-base.c | 691 |
1 files changed, 691 insertions, 0 deletions
diff --git a/drivers/iio/dac/ad5592r-base.c b/drivers/iio/dac/ad5592r-base.c new file mode 100644 index 000000000..69bde5909 --- /dev/null +++ b/drivers/iio/dac/ad5592r-base.c @@ -0,0 +1,691 @@ +/* + * AD5592R Digital <-> Analog converters driver + * + * Copyright 2014-2016 Analog Devices Inc. + * Author: Paul Cercueil <paul.cercueil@analog.com> + * + * Licensed under the GPL-2. + */ + +#include <linux/bitops.h> +#include <linux/delay.h> +#include <linux/iio/iio.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/of.h> +#include <linux/regulator/consumer.h> +#include <linux/gpio/consumer.h> +#include <linux/gpio/driver.h> +#include <linux/gpio.h> +#include <linux/property.h> + +#include <dt-bindings/iio/adi,ad5592r.h> + +#include "ad5592r-base.h" + +static int ad5592r_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + struct ad5592r_state *st = gpiochip_get_data(chip); + int ret = 0; + u8 val; + + mutex_lock(&st->gpio_lock); + + if (st->gpio_out & BIT(offset)) + val = st->gpio_val; + else + ret = st->ops->gpio_read(st, &val); + + mutex_unlock(&st->gpio_lock); + + if (ret < 0) + return ret; + + return !!(val & BIT(offset)); +} + +static void ad5592r_gpio_set(struct gpio_chip *chip, unsigned offset, int value) +{ + struct ad5592r_state *st = gpiochip_get_data(chip); + + mutex_lock(&st->gpio_lock); + + if (value) + st->gpio_val |= BIT(offset); + else + st->gpio_val &= ~BIT(offset); + + st->ops->reg_write(st, AD5592R_REG_GPIO_SET, st->gpio_val); + + mutex_unlock(&st->gpio_lock); +} + +static int ad5592r_gpio_direction_input(struct gpio_chip *chip, unsigned offset) +{ + struct ad5592r_state *st = gpiochip_get_data(chip); + int ret; + + mutex_lock(&st->gpio_lock); + + st->gpio_out &= ~BIT(offset); + st->gpio_in |= BIT(offset); + + ret = st->ops->reg_write(st, AD5592R_REG_GPIO_OUT_EN, st->gpio_out); + if (ret < 0) + goto err_unlock; + + ret = st->ops->reg_write(st, AD5592R_REG_GPIO_IN_EN, st->gpio_in); + +err_unlock: + mutex_unlock(&st->gpio_lock); + + return ret; +} + +static int ad5592r_gpio_direction_output(struct gpio_chip *chip, + unsigned offset, int value) +{ + struct ad5592r_state *st = gpiochip_get_data(chip); + int ret; + + mutex_lock(&st->gpio_lock); + + if (value) + st->gpio_val |= BIT(offset); + else + st->gpio_val &= ~BIT(offset); + + st->gpio_in &= ~BIT(offset); + st->gpio_out |= BIT(offset); + + ret = st->ops->reg_write(st, AD5592R_REG_GPIO_SET, st->gpio_val); + if (ret < 0) + goto err_unlock; + + ret = st->ops->reg_write(st, AD5592R_REG_GPIO_OUT_EN, st->gpio_out); + if (ret < 0) + goto err_unlock; + + ret = st->ops->reg_write(st, AD5592R_REG_GPIO_IN_EN, st->gpio_in); + +err_unlock: + mutex_unlock(&st->gpio_lock); + + return ret; +} + +static int ad5592r_gpio_request(struct gpio_chip *chip, unsigned offset) +{ + struct ad5592r_state *st = gpiochip_get_data(chip); + + if (!(st->gpio_map & BIT(offset))) { + dev_err(st->dev, "GPIO %d is reserved by alternate function\n", + offset); + return -ENODEV; + } + + return 0; +} + +static int ad5592r_gpio_init(struct ad5592r_state *st) +{ + if (!st->gpio_map) + return 0; + + st->gpiochip.label = dev_name(st->dev); + st->gpiochip.base = -1; + st->gpiochip.ngpio = 8; + st->gpiochip.parent = st->dev; + st->gpiochip.can_sleep = true; + st->gpiochip.direction_input = ad5592r_gpio_direction_input; + st->gpiochip.direction_output = ad5592r_gpio_direction_output; + st->gpiochip.get = ad5592r_gpio_get; + st->gpiochip.set = ad5592r_gpio_set; + st->gpiochip.request = ad5592r_gpio_request; + st->gpiochip.owner = THIS_MODULE; + + mutex_init(&st->gpio_lock); + + return gpiochip_add_data(&st->gpiochip, st); +} + +static void ad5592r_gpio_cleanup(struct ad5592r_state *st) +{ + if (st->gpio_map) + gpiochip_remove(&st->gpiochip); +} + +static int ad5592r_reset(struct ad5592r_state *st) +{ + struct gpio_desc *gpio; + struct iio_dev *iio_dev = iio_priv_to_dev(st); + + gpio = devm_gpiod_get_optional(st->dev, "reset", GPIOD_OUT_LOW); + if (IS_ERR(gpio)) + return PTR_ERR(gpio); + + if (gpio) { + udelay(1); + gpiod_set_value(gpio, 1); + } else { + mutex_lock(&iio_dev->mlock); + /* Writing this magic value resets the device */ + st->ops->reg_write(st, AD5592R_REG_RESET, 0xdac); + mutex_unlock(&iio_dev->mlock); + } + + udelay(250); + + return 0; +} + +static int ad5592r_get_vref(struct ad5592r_state *st) +{ + int ret; + + if (st->reg) { + ret = regulator_get_voltage(st->reg); + if (ret < 0) + return ret; + + return ret / 1000; + } else { + return 2500; + } +} + +static int ad5592r_set_channel_modes(struct ad5592r_state *st) +{ + const struct ad5592r_rw_ops *ops = st->ops; + int ret; + unsigned i; + struct iio_dev *iio_dev = iio_priv_to_dev(st); + u8 pulldown = 0, tristate = 0, dac = 0, adc = 0; + u16 read_back; + + for (i = 0; i < st->num_channels; i++) { + switch (st->channel_modes[i]) { + case CH_MODE_DAC: + dac |= BIT(i); + break; + + case CH_MODE_ADC: + adc |= BIT(i); + break; + + case CH_MODE_DAC_AND_ADC: + dac |= BIT(i); + adc |= BIT(i); + break; + + case CH_MODE_GPIO: + st->gpio_map |= BIT(i); + st->gpio_in |= BIT(i); /* Default to input */ + break; + + case CH_MODE_UNUSED: + /* fall-through */ + default: + switch (st->channel_offstate[i]) { + case CH_OFFSTATE_OUT_TRISTATE: + tristate |= BIT(i); + break; + + case CH_OFFSTATE_OUT_LOW: + st->gpio_out |= BIT(i); + break; + + case CH_OFFSTATE_OUT_HIGH: + st->gpio_out |= BIT(i); + st->gpio_val |= BIT(i); + break; + + case CH_OFFSTATE_PULLDOWN: + /* fall-through */ + default: + pulldown |= BIT(i); + break; + } + } + } + + mutex_lock(&iio_dev->mlock); + + /* Pull down unused pins to GND */ + ret = ops->reg_write(st, AD5592R_REG_PULLDOWN, pulldown); + if (ret) + goto err_unlock; + + ret = ops->reg_write(st, AD5592R_REG_TRISTATE, tristate); + if (ret) + goto err_unlock; + + /* Configure pins that we use */ + ret = ops->reg_write(st, AD5592R_REG_DAC_EN, dac); + if (ret) + goto err_unlock; + + ret = ops->reg_write(st, AD5592R_REG_ADC_EN, adc); + if (ret) + goto err_unlock; + + ret = ops->reg_write(st, AD5592R_REG_GPIO_SET, st->gpio_val); + if (ret) + goto err_unlock; + + ret = ops->reg_write(st, AD5592R_REG_GPIO_OUT_EN, st->gpio_out); + if (ret) + goto err_unlock; + + ret = ops->reg_write(st, AD5592R_REG_GPIO_IN_EN, st->gpio_in); + if (ret) + goto err_unlock; + + /* Verify that we can read back at least one register */ + ret = ops->reg_read(st, AD5592R_REG_ADC_EN, &read_back); + if (!ret && (read_back & 0xff) != adc) + ret = -EIO; + +err_unlock: + mutex_unlock(&iio_dev->mlock); + return ret; +} + +static int ad5592r_reset_channel_modes(struct ad5592r_state *st) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(st->channel_modes); i++) + st->channel_modes[i] = CH_MODE_UNUSED; + + return ad5592r_set_channel_modes(st); +} + +static int ad5592r_write_raw(struct iio_dev *iio_dev, + struct iio_chan_spec const *chan, int val, int val2, long mask) +{ + struct ad5592r_state *st = iio_priv(iio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + + if (val >= (1 << chan->scan_type.realbits) || val < 0) + return -EINVAL; + + if (!chan->output) + return -EINVAL; + + mutex_lock(&iio_dev->mlock); + ret = st->ops->write_dac(st, chan->channel, val); + if (!ret) + st->cached_dac[chan->channel] = val; + mutex_unlock(&iio_dev->mlock); + return ret; + case IIO_CHAN_INFO_SCALE: + if (chan->type == IIO_VOLTAGE) { + bool gain; + + if (val == st->scale_avail[0][0] && + val2 == st->scale_avail[0][1]) + gain = false; + else if (val == st->scale_avail[1][0] && + val2 == st->scale_avail[1][1]) + gain = true; + else + return -EINVAL; + + mutex_lock(&iio_dev->mlock); + + ret = st->ops->reg_read(st, AD5592R_REG_CTRL, + &st->cached_gp_ctrl); + if (ret < 0) { + mutex_unlock(&iio_dev->mlock); + return ret; + } + + if (chan->output) { + if (gain) + st->cached_gp_ctrl |= + AD5592R_REG_CTRL_DAC_RANGE; + else + st->cached_gp_ctrl &= + ~AD5592R_REG_CTRL_DAC_RANGE; + } else { + if (gain) + st->cached_gp_ctrl |= + AD5592R_REG_CTRL_ADC_RANGE; + else + st->cached_gp_ctrl &= + ~AD5592R_REG_CTRL_ADC_RANGE; + } + + ret = st->ops->reg_write(st, AD5592R_REG_CTRL, + st->cached_gp_ctrl); + mutex_unlock(&iio_dev->mlock); + + return ret; + } + break; + default: + return -EINVAL; + } + + return 0; +} + +static int ad5592r_read_raw(struct iio_dev *iio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long m) +{ + struct ad5592r_state *st = iio_priv(iio_dev); + u16 read_val; + int ret; + + switch (m) { + case IIO_CHAN_INFO_RAW: + mutex_lock(&iio_dev->mlock); + + if (!chan->output) { + ret = st->ops->read_adc(st, chan->channel, &read_val); + if (ret) + goto unlock; + + if ((read_val >> 12 & 0x7) != (chan->channel & 0x7)) { + dev_err(st->dev, "Error while reading channel %u\n", + chan->channel); + ret = -EIO; + goto unlock; + } + + read_val &= GENMASK(11, 0); + + } else { + read_val = st->cached_dac[chan->channel]; + } + + dev_dbg(st->dev, "Channel %u read: 0x%04hX\n", + chan->channel, read_val); + + *val = (int) read_val; + ret = IIO_VAL_INT; + break; + case IIO_CHAN_INFO_SCALE: + *val = ad5592r_get_vref(st); + + if (chan->type == IIO_TEMP) { + s64 tmp = *val * (3767897513LL / 25LL); + *val = div_s64_rem(tmp, 1000000000LL, val2); + + ret = IIO_VAL_INT_PLUS_MICRO; + } else { + int mult; + + mutex_lock(&iio_dev->mlock); + + if (chan->output) + mult = !!(st->cached_gp_ctrl & + AD5592R_REG_CTRL_DAC_RANGE); + else + mult = !!(st->cached_gp_ctrl & + AD5592R_REG_CTRL_ADC_RANGE); + + *val *= ++mult; + + *val2 = chan->scan_type.realbits; + ret = IIO_VAL_FRACTIONAL_LOG2; + } + break; + case IIO_CHAN_INFO_OFFSET: + ret = ad5592r_get_vref(st); + + mutex_lock(&iio_dev->mlock); + + if (st->cached_gp_ctrl & AD5592R_REG_CTRL_ADC_RANGE) + *val = (-34365 * 25) / ret; + else + *val = (-75365 * 25) / ret; + ret = IIO_VAL_INT; + break; + default: + ret = -EINVAL; + } + +unlock: + mutex_unlock(&iio_dev->mlock); + return ret; +} + +static int ad5592r_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; + + default: + return IIO_VAL_INT_PLUS_MICRO; + } + + return -EINVAL; +} + +static const struct iio_info ad5592r_info = { + .read_raw = ad5592r_read_raw, + .write_raw = ad5592r_write_raw, + .write_raw_get_fmt = ad5592r_write_raw_get_fmt, + .driver_module = THIS_MODULE, +}; + +static ssize_t ad5592r_show_scale_available(struct iio_dev *iio_dev, + uintptr_t private, + const struct iio_chan_spec *chan, + char *buf) +{ + struct ad5592r_state *st = iio_priv(iio_dev); + + return sprintf(buf, "%d.%09u %d.%09u\n", + st->scale_avail[0][0], st->scale_avail[0][1], + st->scale_avail[1][0], st->scale_avail[1][1]); +} + +static struct iio_chan_spec_ext_info ad5592r_ext_info[] = { + { + .name = "scale_available", + .read = ad5592r_show_scale_available, + .shared = true, + }, + {}, +}; + +static void ad5592r_setup_channel(struct iio_dev *iio_dev, + struct iio_chan_spec *chan, bool output, unsigned id) +{ + chan->type = IIO_VOLTAGE; + chan->indexed = 1; + chan->output = output; + chan->channel = id; + chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW); + chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE); + chan->scan_type.sign = 'u'; + chan->scan_type.realbits = 12; + chan->scan_type.storagebits = 16; + chan->ext_info = ad5592r_ext_info; +} + +static int ad5592r_alloc_channels(struct ad5592r_state *st) +{ + unsigned i, curr_channel = 0, + num_channels = st->num_channels; + struct iio_dev *iio_dev = iio_priv_to_dev(st); + struct iio_chan_spec *channels; + struct fwnode_handle *child; + u32 reg, tmp; + int ret; + + device_for_each_child_node(st->dev, child) { + ret = fwnode_property_read_u32(child, "reg", ®); + if (ret || reg >= ARRAY_SIZE(st->channel_modes)) + continue; + + ret = fwnode_property_read_u32(child, "adi,mode", &tmp); + if (!ret) + st->channel_modes[reg] = tmp; + + fwnode_property_read_u32(child, "adi,off-state", &tmp); + if (!ret) + st->channel_offstate[reg] = tmp; + } + + channels = devm_kzalloc(st->dev, + (1 + 2 * num_channels) * sizeof(*channels), GFP_KERNEL); + if (!channels) + return -ENOMEM; + + for (i = 0; i < num_channels; i++) { + switch (st->channel_modes[i]) { + case CH_MODE_DAC: + ad5592r_setup_channel(iio_dev, &channels[curr_channel], + true, i); + curr_channel++; + break; + + case CH_MODE_ADC: + ad5592r_setup_channel(iio_dev, &channels[curr_channel], + false, i); + curr_channel++; + break; + + case CH_MODE_DAC_AND_ADC: + ad5592r_setup_channel(iio_dev, &channels[curr_channel], + true, i); + curr_channel++; + ad5592r_setup_channel(iio_dev, &channels[curr_channel], + false, i); + curr_channel++; + break; + + default: + continue; + } + } + + channels[curr_channel].type = IIO_TEMP; + channels[curr_channel].channel = 8; + channels[curr_channel].info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_OFFSET); + curr_channel++; + + iio_dev->num_channels = curr_channel; + iio_dev->channels = channels; + + return 0; +} + +static void ad5592r_init_scales(struct ad5592r_state *st, int vref_mV) +{ + s64 tmp = (s64)vref_mV * 1000000000LL >> 12; + + st->scale_avail[0][0] = + div_s64_rem(tmp, 1000000000LL, &st->scale_avail[0][1]); + st->scale_avail[1][0] = + div_s64_rem(tmp * 2, 1000000000LL, &st->scale_avail[1][1]); +} + +int ad5592r_probe(struct device *dev, const char *name, + const struct ad5592r_rw_ops *ops) +{ + struct iio_dev *iio_dev; + struct ad5592r_state *st; + int ret; + + iio_dev = devm_iio_device_alloc(dev, sizeof(*st)); + if (!iio_dev) + return -ENOMEM; + + st = iio_priv(iio_dev); + st->dev = dev; + st->ops = ops; + st->num_channels = 8; + dev_set_drvdata(dev, iio_dev); + + st->reg = devm_regulator_get_optional(dev, "vref"); + if (IS_ERR(st->reg)) { + if ((PTR_ERR(st->reg) != -ENODEV) && dev->of_node) + return PTR_ERR(st->reg); + + st->reg = NULL; + } else { + ret = regulator_enable(st->reg); + if (ret) + return ret; + } + + iio_dev->dev.parent = dev; + iio_dev->name = name; + iio_dev->info = &ad5592r_info; + iio_dev->modes = INDIO_DIRECT_MODE; + + ad5592r_init_scales(st, ad5592r_get_vref(st)); + + ret = ad5592r_reset(st); + if (ret) + goto error_disable_reg; + + ret = ops->reg_write(st, AD5592R_REG_PD, + (st->reg == NULL) ? AD5592R_REG_PD_EN_REF : 0); + if (ret) + goto error_disable_reg; + + ret = ad5592r_alloc_channels(st); + if (ret) + goto error_disable_reg; + + ret = ad5592r_set_channel_modes(st); + if (ret) + goto error_reset_ch_modes; + + ret = iio_device_register(iio_dev); + if (ret) + goto error_reset_ch_modes; + + ret = ad5592r_gpio_init(st); + if (ret) + goto error_dev_unregister; + + return 0; + +error_dev_unregister: + iio_device_unregister(iio_dev); + +error_reset_ch_modes: + ad5592r_reset_channel_modes(st); + +error_disable_reg: + if (st->reg) + regulator_disable(st->reg); + + return ret; +} +EXPORT_SYMBOL_GPL(ad5592r_probe); + +int ad5592r_remove(struct device *dev) +{ + struct iio_dev *iio_dev = dev_get_drvdata(dev); + struct ad5592r_state *st = iio_priv(iio_dev); + + iio_device_unregister(iio_dev); + ad5592r_reset_channel_modes(st); + ad5592r_gpio_cleanup(st); + + if (st->reg) + regulator_disable(st->reg); + + return 0; +} +EXPORT_SYMBOL_GPL(ad5592r_remove); + +MODULE_AUTHOR("Paul Cercueil <paul.cercueil@analog.com>"); +MODULE_DESCRIPTION("Analog Devices AD5592R multi-channel converters"); +MODULE_LICENSE("GPL v2"); |