iio: add store_eeprom to mcp4725 dac driver (f17b77d6) · Commits · e / devices / android_kernel_teracube_2e

drivers/iio/dac/mcp4725.c

+62 −2

Original line number	Original line	Diff line number	Diff line
	@@ -12,14 +12,13 @@
	* driver for the Microchip I2C 12-bit digital-to-analog converter (DAC)		* driver for the Microchip I2C 12-bit digital-to-analog converter (DAC)
	* (7-bit I2C slave address 0x60, the three LSBs can be configured in		* (7-bit I2C slave address 0x60, the three LSBs can be configured in
	* hardware)		* hardware)
	*
	* writing the DAC value to EEPROM is not supported
	*/		*/

	#include <linux/module.h>		#include <linux/module.h>
	#include <linux/init.h>		#include <linux/init.h>
	#include <linux/i2c.h>		#include <linux/i2c.h>
	#include <linux/err.h>		#include <linux/err.h>
			#include <linux/delay.h>

	#include <linux/iio/iio.h>		#include <linux/iio/iio.h>
	#include <linux/iio/sysfs.h>		#include <linux/iio/sysfs.h>
	@@ -64,6 +63,66 @@ static SIMPLE_DEV_PM_OPS(mcp4725_pm_ops, mcp4725_suspend, mcp4725_resume);
	#define MCP4725_PM_OPS NULL		#define MCP4725_PM_OPS NULL
	#endif		#endif

			static int mcp4725_store_eeprom(struct device *dev,
			struct device_attribute attr, const char buf, size_t len)
			{
			struct iio_dev *indio_dev = dev_to_iio_dev(dev);
			struct mcp4725_data *data = iio_priv(indio_dev);
			int tries = 20;
			u8 inoutbuf[3];
			bool state;
			int ret;

			ret = strtobool(buf, &state);
			if (ret < 0)
			return ret;

			if (!state)
			return 0;

			inoutbuf[0] = 0x60; /* write EEPROM */
			inoutbuf[1] = data->dac_value >> 4;
			inoutbuf[2] = (data->dac_value & 0xf) << 4;

			ret = i2c_master_send(data->client, inoutbuf, 3);
			if (ret < 0)
			return ret;
			else if (ret != 3)
			return -EIO;

			/* wait for write complete, takes up to 50ms */
			while (tries--) {
			msleep(20);
			ret = i2c_master_recv(data->client, inoutbuf, 3);
			if (ret < 0)
			return ret;
			else if (ret != 3)
			return -EIO;

			if (inoutbuf[0] & 0x80)
			break;
			}

			if (tries < 0) {
			dev_err(&data->client->dev,
			"mcp4725_store_eeprom() failed, incomplete\n");
			return -EIO;
			}

			return len;
			}

			static IIO_DEVICE_ATTR(store_eeprom, S_IWUSR, NULL, mcp4725_store_eeprom, 0);

			static struct attribute *mcp4725_attributes[] = {
			&iio_dev_attr_store_eeprom.dev_attr.attr,
			NULL,
			};

			static const struct attribute_group mcp4725_attribute_group = {
			.attrs = mcp4725_attributes,
			};

	static const struct iio_chan_spec mcp4725_channel = {		static const struct iio_chan_spec mcp4725_channel = {
	.type = IIO_VOLTAGE,		.type = IIO_VOLTAGE,
	.indexed = 1,		.indexed = 1,
	@@ -138,6 +197,7 @@ static int mcp4725_write_raw(struct iio_dev *indio_dev,
	static const struct iio_info mcp4725_info = {		static const struct iio_info mcp4725_info = {
	.read_raw = mcp4725_read_raw,		.read_raw = mcp4725_read_raw,
	.write_raw = mcp4725_write_raw,		.write_raw = mcp4725_write_raw,
			.attrs = &mcp4725_attribute_group,
	.driver_module = THIS_MODULE,		.driver_module = THIS_MODULE,
	};		};