diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
---|---|---|
committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/drivers/iio/adc/ad_sigma_delta.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/drivers/iio/adc/ad_sigma_delta.c')
-rw-r--r-- | kernel/drivers/iio/adc/ad_sigma_delta.c | 553 |
1 files changed, 553 insertions, 0 deletions
diff --git a/kernel/drivers/iio/adc/ad_sigma_delta.c b/kernel/drivers/iio/adc/ad_sigma_delta.c new file mode 100644 index 000000000..d10bd0c97 --- /dev/null +++ b/kernel/drivers/iio/adc/ad_sigma_delta.c @@ -0,0 +1,553 @@ +/* + * Support code for Analog Devices Sigma-Delta ADCs + * + * Copyright 2012 Analog Devices Inc. + * Author: Lars-Peter Clausen <lars@metafoo.de> + * + * Licensed under the GPL-2. + */ + +#include <linux/interrupt.h> +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/spi/spi.h> +#include <linux/err.h> +#include <linux/module.h> + +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/buffer.h> +#include <linux/iio/trigger.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/iio/adc/ad_sigma_delta.h> + +#include <asm/unaligned.h> + + +#define AD_SD_COMM_CHAN_MASK 0x3 + +#define AD_SD_REG_COMM 0x00 +#define AD_SD_REG_DATA 0x03 + +/** + * ad_sd_set_comm() - Set communications register + * + * @sigma_delta: The sigma delta device + * @comm: New value for the communications register + */ +void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm) +{ + /* Some variants use the lower two bits of the communications register + * to select the channel */ + sigma_delta->comm = comm & AD_SD_COMM_CHAN_MASK; +} +EXPORT_SYMBOL_GPL(ad_sd_set_comm); + +/** + * ad_sd_write_reg() - Write a register + * + * @sigma_delta: The sigma delta device + * @reg: Address of the register + * @size: Size of the register (0-3) + * @val: Value to write to the register + * + * Returns 0 on success, an error code otherwise. + **/ +int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg, + unsigned int size, unsigned int val) +{ + uint8_t *data = sigma_delta->data; + struct spi_transfer t = { + .tx_buf = data, + .len = size + 1, + .cs_change = sigma_delta->bus_locked, + }; + struct spi_message m; + int ret; + + data[0] = (reg << sigma_delta->info->addr_shift) | sigma_delta->comm; + + switch (size) { + case 3: + data[1] = val >> 16; + data[2] = val >> 8; + data[3] = val; + break; + case 2: + put_unaligned_be16(val, &data[1]); + break; + case 1: + data[1] = val; + break; + case 0: + break; + default: + return -EINVAL; + } + + spi_message_init(&m); + spi_message_add_tail(&t, &m); + + if (sigma_delta->bus_locked) + ret = spi_sync_locked(sigma_delta->spi, &m); + else + ret = spi_sync(sigma_delta->spi, &m); + + return ret; +} +EXPORT_SYMBOL_GPL(ad_sd_write_reg); + +static int ad_sd_read_reg_raw(struct ad_sigma_delta *sigma_delta, + unsigned int reg, unsigned int size, uint8_t *val) +{ + uint8_t *data = sigma_delta->data; + int ret; + struct spi_transfer t[] = { + { + .tx_buf = data, + .len = 1, + }, { + .rx_buf = val, + .len = size, + .cs_change = sigma_delta->bus_locked, + }, + }; + struct spi_message m; + + spi_message_init(&m); + + if (sigma_delta->info->has_registers) { + data[0] = reg << sigma_delta->info->addr_shift; + data[0] |= sigma_delta->info->read_mask; + spi_message_add_tail(&t[0], &m); + } + spi_message_add_tail(&t[1], &m); + + if (sigma_delta->bus_locked) + ret = spi_sync_locked(sigma_delta->spi, &m); + else + ret = spi_sync(sigma_delta->spi, &m); + + return ret; +} + +/** + * ad_sd_read_reg() - Read a register + * + * @sigma_delta: The sigma delta device + * @reg: Address of the register + * @size: Size of the register (1-4) + * @val: Read value + * + * Returns 0 on success, an error code otherwise. + **/ +int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, + unsigned int reg, unsigned int size, unsigned int *val) +{ + int ret; + + ret = ad_sd_read_reg_raw(sigma_delta, reg, size, sigma_delta->data); + if (ret < 0) + goto out; + + switch (size) { + case 4: + *val = get_unaligned_be32(sigma_delta->data); + break; + case 3: + *val = (sigma_delta->data[0] << 16) | + (sigma_delta->data[1] << 8) | + sigma_delta->data[2]; + break; + case 2: + *val = get_unaligned_be16(sigma_delta->data); + break; + case 1: + *val = sigma_delta->data[0]; + break; + default: + ret = -EINVAL; + break; + } + +out: + return ret; +} +EXPORT_SYMBOL_GPL(ad_sd_read_reg); + +static int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta, + unsigned int mode, unsigned int channel) +{ + int ret; + + ret = ad_sigma_delta_set_channel(sigma_delta, channel); + if (ret) + return ret; + + spi_bus_lock(sigma_delta->spi->master); + sigma_delta->bus_locked = true; + reinit_completion(&sigma_delta->completion); + + ret = ad_sigma_delta_set_mode(sigma_delta, mode); + if (ret < 0) + goto out; + + sigma_delta->irq_dis = false; + enable_irq(sigma_delta->spi->irq); + ret = wait_for_completion_timeout(&sigma_delta->completion, 2*HZ); + if (ret == 0) { + sigma_delta->irq_dis = true; + disable_irq_nosync(sigma_delta->spi->irq); + ret = -EIO; + } else { + ret = 0; + } +out: + sigma_delta->bus_locked = false; + spi_bus_unlock(sigma_delta->spi->master); + ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE); + + return ret; +} + +/** + * ad_sd_calibrate_all() - Performs channel calibration + * @sigma_delta: The sigma delta device + * @cb: Array of channels and calibration type to perform + * @n: Number of items in cb + * + * Returns 0 on success, an error code otherwise. + **/ +int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta, + const struct ad_sd_calib_data *cb, unsigned int n) +{ + unsigned int i; + int ret; + + for (i = 0; i < n; i++) { + ret = ad_sd_calibrate(sigma_delta, cb[i].mode, cb[i].channel); + if (ret) + return ret; + } + + return 0; +} +EXPORT_SYMBOL_GPL(ad_sd_calibrate_all); + +/** + * ad_sigma_delta_single_conversion() - Performs a single data conversion + * @indio_dev: The IIO device + * @chan: The conversion is done for this channel + * @val: Pointer to the location where to store the read value + * + * Returns: 0 on success, an error value otherwise. + */ +int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, int *val) +{ + struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); + unsigned int sample, raw_sample; + int ret = 0; + + if (iio_buffer_enabled(indio_dev)) + return -EBUSY; + + mutex_lock(&indio_dev->mlock); + ad_sigma_delta_set_channel(sigma_delta, chan->address); + + spi_bus_lock(sigma_delta->spi->master); + sigma_delta->bus_locked = true; + reinit_completion(&sigma_delta->completion); + + ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_SINGLE); + + sigma_delta->irq_dis = false; + enable_irq(sigma_delta->spi->irq); + ret = wait_for_completion_interruptible_timeout( + &sigma_delta->completion, HZ); + + sigma_delta->bus_locked = false; + spi_bus_unlock(sigma_delta->spi->master); + + if (ret == 0) + ret = -EIO; + if (ret < 0) + goto out; + + ret = ad_sd_read_reg(sigma_delta, AD_SD_REG_DATA, + DIV_ROUND_UP(chan->scan_type.realbits + chan->scan_type.shift, 8), + &raw_sample); + +out: + if (!sigma_delta->irq_dis) { + disable_irq_nosync(sigma_delta->spi->irq); + sigma_delta->irq_dis = true; + } + + ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE); + mutex_unlock(&indio_dev->mlock); + + if (ret) + return ret; + + sample = raw_sample >> chan->scan_type.shift; + sample &= (1 << chan->scan_type.realbits) - 1; + *val = sample; + + ret = ad_sigma_delta_postprocess_sample(sigma_delta, raw_sample); + if (ret) + return ret; + + return IIO_VAL_INT; +} +EXPORT_SYMBOL_GPL(ad_sigma_delta_single_conversion); + +static int ad_sd_buffer_postenable(struct iio_dev *indio_dev) +{ + struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); + unsigned int channel; + int ret; + + ret = iio_triggered_buffer_postenable(indio_dev); + if (ret < 0) + return ret; + + channel = find_first_bit(indio_dev->active_scan_mask, + indio_dev->masklength); + ret = ad_sigma_delta_set_channel(sigma_delta, + indio_dev->channels[channel].address); + if (ret) + goto err_predisable; + + spi_bus_lock(sigma_delta->spi->master); + sigma_delta->bus_locked = true; + ret = ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_CONTINUOUS); + if (ret) + goto err_unlock; + + sigma_delta->irq_dis = false; + enable_irq(sigma_delta->spi->irq); + + return 0; + +err_unlock: + spi_bus_unlock(sigma_delta->spi->master); +err_predisable: + + return ret; +} + +static int ad_sd_buffer_postdisable(struct iio_dev *indio_dev) +{ + struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); + + reinit_completion(&sigma_delta->completion); + wait_for_completion_timeout(&sigma_delta->completion, HZ); + + if (!sigma_delta->irq_dis) { + disable_irq_nosync(sigma_delta->spi->irq); + sigma_delta->irq_dis = true; + } + + ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE); + + sigma_delta->bus_locked = false; + return spi_bus_unlock(sigma_delta->spi->master); +} + +static irqreturn_t ad_sd_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); + unsigned int reg_size; + uint8_t data[16]; + int ret; + + memset(data, 0x00, 16); + + reg_size = indio_dev->channels[0].scan_type.realbits + + indio_dev->channels[0].scan_type.shift; + reg_size = DIV_ROUND_UP(reg_size, 8); + + switch (reg_size) { + case 4: + case 2: + case 1: + ret = ad_sd_read_reg_raw(sigma_delta, AD_SD_REG_DATA, + reg_size, &data[0]); + break; + case 3: + /* We store 24 bit samples in a 32 bit word. Keep the upper + * byte set to zero. */ + ret = ad_sd_read_reg_raw(sigma_delta, AD_SD_REG_DATA, + reg_size, &data[1]); + break; + } + + iio_push_to_buffers_with_timestamp(indio_dev, data, pf->timestamp); + + iio_trigger_notify_done(indio_dev->trig); + sigma_delta->irq_dis = false; + enable_irq(sigma_delta->spi->irq); + + return IRQ_HANDLED; +} + +static const struct iio_buffer_setup_ops ad_sd_buffer_setup_ops = { + .postenable = &ad_sd_buffer_postenable, + .predisable = &iio_triggered_buffer_predisable, + .postdisable = &ad_sd_buffer_postdisable, + .validate_scan_mask = &iio_validate_scan_mask_onehot, +}; + +static irqreturn_t ad_sd_data_rdy_trig_poll(int irq, void *private) +{ + struct ad_sigma_delta *sigma_delta = private; + + complete(&sigma_delta->completion); + disable_irq_nosync(irq); + sigma_delta->irq_dis = true; + iio_trigger_poll(sigma_delta->trig); + + return IRQ_HANDLED; +} + +/** + * ad_sd_validate_trigger() - validate_trigger callback for ad_sigma_delta devices + * @indio_dev: The IIO device + * @trig: The new trigger + * + * Returns: 0 if the 'trig' matches the trigger registered by the ad_sigma_delta + * device, -EINVAL otherwise. + */ +int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig) +{ + struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); + + if (sigma_delta->trig != trig) + return -EINVAL; + + return 0; +} +EXPORT_SYMBOL_GPL(ad_sd_validate_trigger); + +static const struct iio_trigger_ops ad_sd_trigger_ops = { + .owner = THIS_MODULE, +}; + +static int ad_sd_probe_trigger(struct iio_dev *indio_dev) +{ + struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); + int ret; + + sigma_delta->trig = iio_trigger_alloc("%s-dev%d", indio_dev->name, + indio_dev->id); + if (sigma_delta->trig == NULL) { + ret = -ENOMEM; + goto error_ret; + } + sigma_delta->trig->ops = &ad_sd_trigger_ops; + init_completion(&sigma_delta->completion); + + ret = request_irq(sigma_delta->spi->irq, + ad_sd_data_rdy_trig_poll, + IRQF_TRIGGER_LOW, + indio_dev->name, + sigma_delta); + if (ret) + goto error_free_trig; + + if (!sigma_delta->irq_dis) { + sigma_delta->irq_dis = true; + disable_irq_nosync(sigma_delta->spi->irq); + } + sigma_delta->trig->dev.parent = &sigma_delta->spi->dev; + iio_trigger_set_drvdata(sigma_delta->trig, sigma_delta); + + ret = iio_trigger_register(sigma_delta->trig); + if (ret) + goto error_free_irq; + + /* select default trigger */ + indio_dev->trig = iio_trigger_get(sigma_delta->trig); + + return 0; + +error_free_irq: + free_irq(sigma_delta->spi->irq, sigma_delta); +error_free_trig: + iio_trigger_free(sigma_delta->trig); +error_ret: + return ret; +} + +static void ad_sd_remove_trigger(struct iio_dev *indio_dev) +{ + struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); + + iio_trigger_unregister(sigma_delta->trig); + free_irq(sigma_delta->spi->irq, sigma_delta); + iio_trigger_free(sigma_delta->trig); +} + +/** + * ad_sd_setup_buffer_and_trigger() - + * @indio_dev: The IIO device + */ +int ad_sd_setup_buffer_and_trigger(struct iio_dev *indio_dev) +{ + int ret; + + ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time, + &ad_sd_trigger_handler, &ad_sd_buffer_setup_ops); + if (ret) + return ret; + + ret = ad_sd_probe_trigger(indio_dev); + if (ret) { + iio_triggered_buffer_cleanup(indio_dev); + return ret; + } + + return 0; +} +EXPORT_SYMBOL_GPL(ad_sd_setup_buffer_and_trigger); + +/** + * ad_sd_cleanup_buffer_and_trigger() - + * @indio_dev: The IIO device + */ +void ad_sd_cleanup_buffer_and_trigger(struct iio_dev *indio_dev) +{ + ad_sd_remove_trigger(indio_dev); + iio_triggered_buffer_cleanup(indio_dev); +} +EXPORT_SYMBOL_GPL(ad_sd_cleanup_buffer_and_trigger); + +/** + * ad_sd_init() - Initializes a ad_sigma_delta struct + * @sigma_delta: The ad_sigma_delta device + * @indio_dev: The IIO device which the Sigma Delta device is used for + * @spi: The SPI device for the ad_sigma_delta device + * @info: Device specific callbacks and options + * + * This function needs to be called before any other operations are performed on + * the ad_sigma_delta struct. + */ +int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev, + struct spi_device *spi, const struct ad_sigma_delta_info *info) +{ + sigma_delta->spi = spi; + sigma_delta->info = info; + iio_device_set_drvdata(indio_dev, sigma_delta); + + return 0; +} +EXPORT_SYMBOL_GPL(ad_sd_init); + +MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); +MODULE_DESCRIPTION("Analog Devices Sigma-Delta ADCs"); +MODULE_LICENSE("GPL v2"); |