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	Diff line number	Diff line
		@@ -12,14 +12,13 @@
		* 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
		* hardware)
		*
		* writing the DAC value to EEPROM is not supported
		*/

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

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