Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / iio / adc / ti-adc081c.c

diff --git a/kernel/drivers/iio/adc/ti-adc081c.c b/kernel/drivers/iio/adc/ti-adc081c.c
new file mode 100644 (file)
index 0000000..b3a82b4
--- /dev/null
+++ b/kernel/drivers/iio/adc/ti-adc081c.c
@@ -0,0 +1,154 @@
+/*
+ * Copyright (C) 2012 Avionic Design GmbH
+ *
+ * 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/err.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+#include <linux/iio/iio.h>
+#include <linux/regulator/consumer.h>
+
+struct adc081c {
+       struct i2c_client *i2c;
+       struct regulator *ref;
+};
+
+#define REG_CONV_RES 0x00
+
+static int adc081c_read_raw(struct iio_dev *iio,
+                           struct iio_chan_spec const *channel, int *value,
+                           int *shift, long mask)
+{
+       struct adc081c *adc = iio_priv(iio);
+       int err;
+
+       switch (mask) {
+       case IIO_CHAN_INFO_RAW:
+               err = i2c_smbus_read_word_swapped(adc->i2c, REG_CONV_RES);
+               if (err < 0)
+                       return err;
+
+               *value = (err >> 4) & 0xff;
+               return IIO_VAL_INT;
+
+       case IIO_CHAN_INFO_SCALE:
+               err = regulator_get_voltage(adc->ref);
+               if (err < 0)
+                       return err;
+
+               *value = err / 1000;
+               *shift = 8;
+
+               return IIO_VAL_FRACTIONAL_LOG2;
+
+       default:
+               break;
+       }
+
+       return -EINVAL;
+}
+
+static const struct iio_chan_spec adc081c_channel = {
+       .type = IIO_VOLTAGE,
+       .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
+       .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+};
+
+static const struct iio_info adc081c_info = {
+       .read_raw = adc081c_read_raw,
+       .driver_module = THIS_MODULE,
+};
+
+static int adc081c_probe(struct i2c_client *client,
+                        const struct i2c_device_id *id)
+{
+       struct iio_dev *iio;
+       struct adc081c *adc;
+       int err;
+
+       if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
+               return -ENODEV;
+
+       iio = devm_iio_device_alloc(&client->dev, sizeof(*adc));
+       if (!iio)
+               return -ENOMEM;
+
+       adc = iio_priv(iio);
+       adc->i2c = client;
+
+       adc->ref = devm_regulator_get(&client->dev, "vref");
+       if (IS_ERR(adc->ref))
+               return PTR_ERR(adc->ref);
+
+       err = regulator_enable(adc->ref);
+       if (err < 0)
+               return err;
+
+       iio->dev.parent = &client->dev;
+       iio->name = dev_name(&client->dev);
+       iio->modes = INDIO_DIRECT_MODE;
+       iio->info = &adc081c_info;
+
+       iio->channels = &adc081c_channel;
+       iio->num_channels = 1;
+
+       err = iio_device_register(iio);
+       if (err < 0)
+               goto regulator_disable;
+
+       i2c_set_clientdata(client, iio);
+
+       return 0;
+
+regulator_disable:
+       regulator_disable(adc->ref);
+
+       return err;
+}
+
+static int adc081c_remove(struct i2c_client *client)
+{
+       struct iio_dev *iio = i2c_get_clientdata(client);
+       struct adc081c *adc = iio_priv(iio);
+
+       iio_device_unregister(iio);
+       regulator_disable(adc->ref);
+
+       return 0;
+}
+
+static const struct i2c_device_id adc081c_id[] = {
+       { "adc081c", 0 },
+       { }
+};
+MODULE_DEVICE_TABLE(i2c, adc081c_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id adc081c_of_match[] = {
+       { .compatible = "ti,adc081c" },
+       { }
+};
+MODULE_DEVICE_TABLE(of, adc081c_of_match);
+#endif
+
+static struct i2c_driver adc081c_driver = {
+       .driver = {
+               .name = "adc081c",
+               .owner = THIS_MODULE,
+               .of_match_table = of_match_ptr(adc081c_of_match),
+       },
+       .probe = adc081c_probe,
+       .remove = adc081c_remove,
+       .id_table = adc081c_id,
+};
+module_i2c_driver(adc081c_driver);
+
+MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
+MODULE_DESCRIPTION("Texas Instruments ADC081C021/027 driver");
+MODULE_LICENSE("GPL v2");