iio: adc: Cosmic Circuits 10001 ADC driver (1664f6a5) · Commits · 戴 / test

drivers/iio/adc/Kconfig

+11 −0

Original line number	Diff line number	Diff line
		@@ -135,6 +135,17 @@ config AXP288_ADC
		device. Depending on platform configuration, this general purpose ADC can
		be used for sampling sensors such as thermal resistors.

		config CC10001_ADC
		tristate "Cosmic Circuits 10001 ADC driver"
		depends on HAS_IOMEM \|\| HAVE_CLK \|\| REGULATOR
		select IIO_BUFFER
		select IIO_TRIGGERED_BUFFER
		help
		Say yes here to build support for Cosmic Circuits 10001 ADC.

		This driver can also be built as a module. If so, the module will be
		called cc10001_adc.

		config EXYNOS_ADC
		tristate "Exynos ADC driver support"
		depends on ARCH_EXYNOS \|\| ARCH_S3C24XX \|\| ARCH_S3C64XX \|\| (OF && COMPILE_TEST)

drivers/iio/adc/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -15,6 +15,7 @@ obj-$(CONFIG_AD7887) += ad7887.o
		obj-$(CONFIG_AD799X) += ad799x.o
		obj-$(CONFIG_AT91_ADC) += at91_adc.o
		obj-$(CONFIG_AXP288_ADC) += axp288_adc.o
		obj-$(CONFIG_CC10001_ADC) += cc10001_adc.o
		obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o
		obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
		obj-$(CONFIG_MAX1027) += max1027.o

drivers/iio/adc/cc10001_adc.c

0 → 100644

+423 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (c) 2014-2015 Imagination Technologies Ltd.
		*
		* 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.
		*
		*/

		#include <linux/clk.h>
		#include <linux/delay.h>
		#include <linux/err.h>
		#include <linux/kernel.h>
		#include <linux/module.h>
		#include <linux/of.h>
		#include <linux/of_device.h>
		#include <linux/platform_device.h>
		#include <linux/regulator/consumer.h>
		#include <linux/slab.h>

		#include <linux/iio/buffer.h>
		#include <linux/iio/iio.h>
		#include <linux/iio/sysfs.h>
		#include <linux/iio/trigger.h>
		#include <linux/iio/trigger_consumer.h>
		#include <linux/iio/triggered_buffer.h>

		/* Registers */
		#define CC10001_ADC_CONFIG 0x00
		#define CC10001_ADC_START_CONV BIT(4)
		#define CC10001_ADC_MODE_SINGLE_CONV BIT(5)

		#define CC10001_ADC_DDATA_OUT 0x04
		#define CC10001_ADC_EOC 0x08
		#define CC10001_ADC_EOC_SET BIT(0)

		#define CC10001_ADC_CHSEL_SAMPLED 0x0c
		#define CC10001_ADC_POWER_UP 0x10
		#define CC10001_ADC_POWER_UP_SET BIT(0)
		#define CC10001_ADC_DEBUG 0x14
		#define CC10001_ADC_DATA_COUNT 0x20

		#define CC10001_ADC_DATA_MASK GENMASK(9, 0)
		#define CC10001_ADC_NUM_CHANNELS 8
		#define CC10001_ADC_CH_MASK GENMASK(2, 0)

		#define CC10001_INVALID_SAMPLED 0xffff
		#define CC10001_MAX_POLL_COUNT 20

		/*
		* As per device specification, wait six clock cycles after power-up to
		* activate START. Since adding two more clock cycles delay does not
		* impact the performance too much, we are adding two additional cycles delay
		* intentionally here.
		*/
		#define CC10001_WAIT_CYCLES 8

		struct cc10001_adc_device {
		void __iomem *reg_base;
		struct clk *adc_clk;
		struct regulator *reg;
		u16 *buf;

		struct mutex lock;
		unsigned long channel_map;
		unsigned int start_delay_ns;
		unsigned int eoc_delay_ns;
		};

		static inline void cc10001_adc_write_reg(struct cc10001_adc_device *adc_dev,
		u32 reg, u32 val)
		{
		writel(val, adc_dev->reg_base + reg);
		}

		static inline u32 cc10001_adc_read_reg(struct cc10001_adc_device *adc_dev,
		u32 reg)
		{
		return readl(adc_dev->reg_base + reg);
		}

		static void cc10001_adc_start(struct cc10001_adc_device *adc_dev,
		unsigned int channel)
		{
		u32 val;

		/* Channel selection and mode of operation */
		val = (channel & CC10001_ADC_CH_MASK) \| CC10001_ADC_MODE_SINGLE_CONV;
		cc10001_adc_write_reg(adc_dev, CC10001_ADC_CONFIG, val);

		val = cc10001_adc_read_reg(adc_dev, CC10001_ADC_CONFIG);
		val = val \| CC10001_ADC_START_CONV;
		cc10001_adc_write_reg(adc_dev, CC10001_ADC_CONFIG, val);
		}

		static u16 cc10001_adc_poll_done(struct iio_dev *indio_dev,
		unsigned int channel,
		unsigned int delay)
		{
		struct cc10001_adc_device *adc_dev = iio_priv(indio_dev);
		unsigned int poll_count = 0;

		while (!(cc10001_adc_read_reg(adc_dev, CC10001_ADC_EOC) &
		CC10001_ADC_EOC_SET)) {

		ndelay(delay);
		if (poll_count++ == CC10001_MAX_POLL_COUNT)
		return CC10001_INVALID_SAMPLED;
		}

		poll_count = 0;
		while ((cc10001_adc_read_reg(adc_dev, CC10001_ADC_CHSEL_SAMPLED) &
		CC10001_ADC_CH_MASK) != channel) {

		ndelay(delay);
		if (poll_count++ == CC10001_MAX_POLL_COUNT)
		return CC10001_INVALID_SAMPLED;
		}

		/* Read the 10 bit output register */
		return cc10001_adc_read_reg(adc_dev, CC10001_ADC_DDATA_OUT) &
		CC10001_ADC_DATA_MASK;
		}

		static irqreturn_t cc10001_adc_trigger_h(int irq, void *p)
		{
		struct cc10001_adc_device *adc_dev;
		struct iio_poll_func *pf = p;
		struct iio_dev *indio_dev;
		unsigned int delay_ns;
		unsigned int channel;
		bool sample_invalid;
		u16 *data;
		int i;

		indio_dev = pf->indio_dev;
		adc_dev = iio_priv(indio_dev);
		data = adc_dev->buf;

		mutex_lock(&adc_dev->lock);

		cc10001_adc_write_reg(adc_dev, CC10001_ADC_POWER_UP,
		CC10001_ADC_POWER_UP_SET);

		/* Wait for 8 (6+2) clock cycles before activating START */
		ndelay(adc_dev->start_delay_ns);

		/* Calculate delay step for eoc and sampled data */
		delay_ns = adc_dev->eoc_delay_ns / CC10001_MAX_POLL_COUNT;

		i = 0;
		sample_invalid = false;
		for_each_set_bit(channel, indio_dev->active_scan_mask,
		indio_dev->masklength) {

		cc10001_adc_start(adc_dev, channel);

		data[i] = cc10001_adc_poll_done(indio_dev, channel, delay_ns);
		if (data[i] == CC10001_INVALID_SAMPLED) {
		dev_warn(&indio_dev->dev,
		"invalid sample on channel %d\n", channel);
		sample_invalid = true;
		goto done;
		}
		i++;
		}

		done:
		cc10001_adc_write_reg(adc_dev, CC10001_ADC_POWER_UP, 0);

		mutex_unlock(&adc_dev->lock);

		if (!sample_invalid)
		iio_push_to_buffers_with_timestamp(indio_dev, data,
		iio_get_time_ns());
		iio_trigger_notify_done(indio_dev->trig);

		return IRQ_HANDLED;
		}

		static u16 cc10001_adc_read_raw_voltage(struct iio_dev *indio_dev,
		struct iio_chan_spec const *chan)
		{
		struct cc10001_adc_device *adc_dev = iio_priv(indio_dev);
		unsigned int delay_ns;
		u16 val;

		cc10001_adc_write_reg(adc_dev, CC10001_ADC_POWER_UP,
		CC10001_ADC_POWER_UP_SET);

		/* Wait for 8 (6+2) clock cycles before activating START */
		ndelay(adc_dev->start_delay_ns);

		/* Calculate delay step for eoc and sampled data */
		delay_ns = adc_dev->eoc_delay_ns / CC10001_MAX_POLL_COUNT;

		cc10001_adc_start(adc_dev, chan->channel);

		val = cc10001_adc_poll_done(indio_dev, chan->channel, delay_ns);

		cc10001_adc_write_reg(adc_dev, CC10001_ADC_POWER_UP, 0);

		return val;
		}

		static int cc10001_adc_read_raw(struct iio_dev *indio_dev,
		struct iio_chan_spec const *chan,
		int val, int val2, long mask)
		{
		struct cc10001_adc_device *adc_dev = iio_priv(indio_dev);
		int ret;

		switch (mask) {
		case IIO_CHAN_INFO_RAW:
		if (iio_buffer_enabled(indio_dev))
		return -EBUSY;
		mutex_lock(&adc_dev->lock);
		*val = cc10001_adc_read_raw_voltage(indio_dev, chan);
		mutex_unlock(&adc_dev->lock);

		if (*val == CC10001_INVALID_SAMPLED)
		return -EIO;
		return IIO_VAL_INT;

		case IIO_CHAN_INFO_SCALE:
		ret = regulator_get_voltage(adc_dev->reg);
		if (ret)
		return ret;

		*val = ret / 1000;
		*val2 = chan->scan_type.realbits;
		return IIO_VAL_FRACTIONAL_LOG2;

		default:
		return -EINVAL;
		}
		}

		static int cc10001_update_scan_mode(struct iio_dev *indio_dev,
		const unsigned long *scan_mask)
		{
		struct cc10001_adc_device *adc_dev = iio_priv(indio_dev);

		kfree(adc_dev->buf);
		adc_dev->buf = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
		if (!adc_dev->buf)
		return -ENOMEM;

		return 0;
		}

		static const struct iio_info cc10001_adc_info = {
		.driver_module = THIS_MODULE,
		.read_raw = &cc10001_adc_read_raw,
		.update_scan_mode = &cc10001_update_scan_mode,
		};

		static int cc10001_adc_channel_init(struct iio_dev *indio_dev)
		{
		struct cc10001_adc_device *adc_dev = iio_priv(indio_dev);
		struct iio_chan_spec chan_array, timestamp;
		unsigned int bit, idx = 0;

		indio_dev->num_channels = bitmap_weight(&adc_dev->channel_map,
		CC10001_ADC_NUM_CHANNELS);

		chan_array = devm_kcalloc(&indio_dev->dev, indio_dev->num_channels + 1,
		sizeof(struct iio_chan_spec),
		GFP_KERNEL);
		if (!chan_array)
		return -ENOMEM;

		for_each_set_bit(bit, &adc_dev->channel_map, CC10001_ADC_NUM_CHANNELS) {
		struct iio_chan_spec *chan = &chan_array[idx];

		chan->type = IIO_VOLTAGE;
		chan->indexed = 1;
		chan->channel = bit;
		chan->scan_index = idx;
		chan->scan_type.sign = 'u';
		chan->scan_type.realbits = 10;
		chan->scan_type.storagebits = 16;
		chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
		chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
		idx++;
		}

		timestamp = &chan_array[idx];
		timestamp->type = IIO_TIMESTAMP;
		timestamp->channel = -1;
		timestamp->scan_index = idx;
		timestamp->scan_type.sign = 's';
		timestamp->scan_type.realbits = 64;
		timestamp->scan_type.storagebits = 64;

		indio_dev->channels = chan_array;

		return 0;
		}

		static int cc10001_adc_probe(struct platform_device *pdev)
		{
		struct device_node *node = pdev->dev.of_node;
		struct cc10001_adc_device *adc_dev;
		unsigned long adc_clk_rate;
		struct resource *res;
		struct iio_dev *indio_dev;
		int ret;

		indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc_dev));
		if (indio_dev == NULL)
		return -ENOMEM;

		adc_dev = iio_priv(indio_dev);

		adc_dev->channel_map = GENMASK(CC10001_ADC_NUM_CHANNELS - 1, 0);
		if (!of_property_read_u32(node, "adc-reserved-channels", &ret))
		adc_dev->channel_map &= ~ret;

		adc_dev->reg = devm_regulator_get(&pdev->dev, "vref");
		if (IS_ERR(adc_dev->reg))
		return PTR_ERR(adc_dev->reg);

		ret = regulator_enable(adc_dev->reg);
		if (ret)
		return ret;

		indio_dev->dev.parent = &pdev->dev;
		indio_dev->name = dev_name(&pdev->dev);
		indio_dev->info = &cc10001_adc_info;
		indio_dev->modes = INDIO_DIRECT_MODE;

		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
		adc_dev->reg_base = devm_ioremap_resource(&pdev->dev, res);
		if (IS_ERR(adc_dev->reg_base)) {
		ret = PTR_ERR(adc_dev->reg_base);
		goto err_disable_reg;
		}

		adc_dev->adc_clk = devm_clk_get(&pdev->dev, "adc");
		if (IS_ERR(adc_dev->adc_clk)) {
		dev_err(&pdev->dev, "failed to get the clock\n");
		ret = PTR_ERR(adc_dev->adc_clk);
		goto err_disable_reg;
		}

		ret = clk_prepare_enable(adc_dev->adc_clk);
		if (ret) {
		dev_err(&pdev->dev, "failed to enable the clock\n");
		goto err_disable_reg;
		}

		adc_clk_rate = clk_get_rate(adc_dev->adc_clk);
		if (!adc_clk_rate) {
		ret = -EINVAL;
		dev_err(&pdev->dev, "null clock rate!\n");
		goto err_disable_clk;
		}

		adc_dev->eoc_delay_ns = NSEC_PER_SEC / adc_clk_rate;
		adc_dev->start_delay_ns = adc_dev->eoc_delay_ns * CC10001_WAIT_CYCLES;

		/* Setup the ADC channels available on the device */
		ret = cc10001_adc_channel_init(indio_dev);
		if (ret < 0)
		goto err_disable_clk;

		mutex_init(&adc_dev->lock);

		ret = iio_triggered_buffer_setup(indio_dev, NULL,
		&cc10001_adc_trigger_h, NULL);
		if (ret < 0)
		goto err_disable_clk;

		ret = iio_device_register(indio_dev);
		if (ret < 0)
		goto err_cleanup_buffer;

		platform_set_drvdata(pdev, indio_dev);

		return 0;

		err_cleanup_buffer:
		iio_triggered_buffer_cleanup(indio_dev);
		err_disable_clk:
		clk_disable_unprepare(adc_dev->adc_clk);
		err_disable_reg:
		regulator_disable(adc_dev->reg);
		return ret;
		}

		static int cc10001_adc_remove(struct platform_device *pdev)
		{
		struct iio_dev *indio_dev = platform_get_drvdata(pdev);
		struct cc10001_adc_device *adc_dev = iio_priv(indio_dev);

		iio_device_unregister(indio_dev);
		iio_triggered_buffer_cleanup(indio_dev);
		clk_disable_unprepare(adc_dev->adc_clk);
		regulator_disable(adc_dev->reg);

		return 0;
		}

		static const struct of_device_id cc10001_adc_dt_ids[] = {
		{ .compatible = "cosmic,10001-adc", },
		{ }
		};
		MODULE_DEVICE_TABLE(of, cc10001_adc_dt_ids);

		static struct platform_driver cc10001_adc_driver = {
		.driver = {
		.name = "cc10001-adc",
		.of_match_table = cc10001_adc_dt_ids,
		},
		.probe = cc10001_adc_probe,
		.remove = cc10001_adc_remove,
		};
		module_platform_driver(cc10001_adc_driver);

		MODULE_AUTHOR("Phani Movva <Phani.Movva@imgtec.com>");
		MODULE_DESCRIPTION("Cosmic Circuits ADC driver");
		MODULE_LICENSE("GPL v2");

Admin message