regulator: new drivers for AD5398 and AD5821
The AD5398 and AD5821 are single 10-bit DAC with 120 mA output current
sink capability. They feature an internal reference and operates from
a single 2.7 V to 5.5 V supply.
This driver supports both the AD5398 and the AD5821. It adapts into the
voltage and current framework.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
diff --git a/drivers/regulator/ad5398.c b/drivers/regulator/ad5398.c
new file mode 100644
index 0000000..6de6bda
--- /dev/null
+++ b/drivers/regulator/ad5398.c
@@ -0,0 +1,288 @@
+/*
+ * Voltage and current regulation for AD5398 and AD5821
+ *
+ * Copyright 2010 Analog Devices Inc.
+ *
+ * Enter bugs at http://blackfin.uclinux.org/
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+
+#define AD5398_CURRENT_EN_MASK 0x8000
+
+struct ad5398_chip_info {
+ struct i2c_client *client;
+ int min_uA;
+ int max_uA;
+ unsigned int current_level;
+ unsigned int current_mask;
+ unsigned int current_offset;
+ struct regulator_dev rdev;
+};
+
+static int ad5398_calc_current(struct ad5398_chip_info *chip,
+ unsigned selector)
+{
+ unsigned range_uA = chip->max_uA - chip->min_uA;
+
+ return chip->min_uA + (selector * range_uA / chip->current_level);
+}
+
+static int ad5398_read_reg(struct i2c_client *client, unsigned short *data)
+{
+ unsigned short val;
+ int ret;
+
+ ret = i2c_master_recv(client, (char *)&val, 2);
+ if (ret < 0) {
+ dev_err(&client->dev, "I2C read error\n");
+ return ret;
+ }
+ *data = be16_to_cpu(val);
+
+ return ret;
+}
+
+static int ad5398_write_reg(struct i2c_client *client, const unsigned short data)
+{
+ unsigned short val;
+ int ret;
+
+ val = cpu_to_be16(data);
+ ret = i2c_master_send(client, (char *)&val, 2);
+ if (ret < 0)
+ dev_err(&client->dev, "I2C write error\n");
+
+ return ret;
+}
+
+static int ad5398_get_current_limit(struct regulator_dev *rdev)
+{
+ struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
+ struct i2c_client *client = chip->client;
+ unsigned short data;
+ int ret;
+
+ ret = ad5398_read_reg(client, &data);
+ if (ret < 0)
+ return ret;
+
+ ret = (data & chip->current_mask) >> chip->current_offset;
+
+ return ad5398_calc_current(chip, ret);
+}
+
+static int ad5398_set_current_limit(struct regulator_dev *rdev, int min_uA, int max_uA)
+{
+ struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
+ struct i2c_client *client = chip->client;
+ unsigned range_uA = chip->max_uA - chip->min_uA;
+ unsigned selector;
+ unsigned short data;
+ int ret;
+
+ if (min_uA > chip->max_uA || min_uA < chip->min_uA)
+ return -EINVAL;
+ if (max_uA > chip->max_uA || max_uA < chip->min_uA)
+ return -EINVAL;
+
+ selector = ((min_uA - chip->min_uA) * chip->current_level +
+ range_uA - 1) / range_uA;
+ if (ad5398_calc_current(chip, selector) > max_uA)
+ return -EINVAL;
+
+ dev_dbg(&client->dev, "changing current %dmA\n",
+ ad5398_calc_current(chip, selector) / 1000);
+
+ /* read chip enable bit */
+ ret = ad5398_read_reg(client, &data);
+ if (ret < 0)
+ return ret;
+
+ /* prepare register data */
+ selector = (selector << chip->current_offset) & chip->current_mask;
+ data = (unsigned short)selector | (data & AD5398_CURRENT_EN_MASK);
+
+ /* write the new current value back as well as enable bit */
+ ret = ad5398_write_reg(client, data);
+
+ return ret;
+}
+
+static int ad5398_is_enabled(struct regulator_dev *rdev)
+{
+ struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
+ struct i2c_client *client = chip->client;
+ unsigned short data;
+ int ret;
+
+ ret = ad5398_read_reg(client, &data);
+ if (ret < 0)
+ return ret;
+
+ if (data & AD5398_CURRENT_EN_MASK)
+ return 1;
+ else
+ return 0;
+}
+
+static int ad5398_enable(struct regulator_dev *rdev)
+{
+ struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
+ struct i2c_client *client = chip->client;
+ unsigned short data;
+ int ret;
+
+ ret = ad5398_read_reg(client, &data);
+ if (ret < 0)
+ return ret;
+
+ if (data & AD5398_CURRENT_EN_MASK)
+ return 0;
+
+ data |= AD5398_CURRENT_EN_MASK;
+
+ ret = ad5398_write_reg(client, data);
+
+ return ret;
+}
+
+static int ad5398_disable(struct regulator_dev *rdev)
+{
+ struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
+ struct i2c_client *client = chip->client;
+ unsigned short data;
+ int ret;
+
+ ret = ad5398_read_reg(client, &data);
+ if (ret < 0)
+ return ret;
+
+ if (!(data & AD5398_CURRENT_EN_MASK))
+ return 0;
+
+ data &= ~AD5398_CURRENT_EN_MASK;
+
+ ret = ad5398_write_reg(client, data);
+
+ return ret;
+}
+
+static struct regulator_ops ad5398_ops = {
+ .get_current_limit = ad5398_get_current_limit,
+ .set_current_limit = ad5398_set_current_limit,
+ .enable = ad5398_enable,
+ .disable = ad5398_disable,
+ .is_enabled = ad5398_is_enabled,
+};
+
+static struct regulator_desc ad5398_reg = {
+ .name = "isink",
+ .id = 0,
+ .ops = &ad5398_ops,
+ .type = REGULATOR_CURRENT,
+ .owner = THIS_MODULE,
+};
+
+struct ad5398_current_data_format {
+ int current_bits;
+ int current_offset;
+ int min_uA;
+ int max_uA;
+};
+
+static const struct ad5398_current_data_format df_10_4_120 = {10, 4, 0, 120000};
+
+static const struct i2c_device_id ad5398_id[] = {
+ { "ad5398", (kernel_ulong_t)&df_10_4_120 },
+ { "ad5821", (kernel_ulong_t)&df_10_4_120 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ad5398_id);
+
+static int __devinit ad5398_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct regulator_dev *rdev;
+ struct regulator_init_data *init_data = client->dev.platform_data;
+ struct ad5398_chip_info *chip;
+ const struct ad5398_current_data_format *df =
+ (struct ad5398_current_data_format *)id->driver_data;
+ int ret;
+
+ if (!init_data)
+ return -EINVAL;
+
+ chip = kzalloc(sizeof(*chip), GFP_KERNEL);
+ if (!chip)
+ return -ENOMEM;
+
+ chip->client = client;
+
+ chip->min_uA = df->min_uA;
+ chip->max_uA = df->max_uA;
+ chip->current_level = 1 << df->current_bits;
+ chip->current_offset = df->current_offset;
+ chip->current_mask = (chip->current_level - 1) << chip->current_offset;
+
+ rdev = regulator_register(&ad5398_reg, &client->dev, init_data, chip);
+ if (IS_ERR(rdev)) {
+ ret = PTR_ERR(rdev);
+ dev_err(&client->dev, "failed to register %s %s\n",
+ id->name, ad5398_reg.name);
+ goto err;
+ }
+
+ i2c_set_clientdata(client, chip);
+ dev_dbg(&client->dev, "%s regulator driver is registered.\n", id->name);
+ return 0;
+
+err:
+ kfree(chip);
+ return ret;
+}
+
+static int __devexit ad5398_remove(struct i2c_client *client)
+{
+ struct ad5398_chip_info *chip = i2c_get_clientdata(client);
+
+ regulator_unregister(&chip->rdev);
+ kfree(chip);
+ i2c_set_clientdata(client, NULL);
+
+ return 0;
+}
+
+static struct i2c_driver ad5398_driver = {
+ .probe = ad5398_probe,
+ .remove = __devexit_p(ad5398_remove),
+ .driver = {
+ .name = "ad5398",
+ },
+ .id_table = ad5398_id,
+};
+
+static int __init ad5398_init(void)
+{
+ return i2c_add_driver(&ad5398_driver);
+}
+module_init(ad5398_init);
+
+static void __exit ad5398_exit(void)
+{
+ i2c_del_driver(&ad5398_driver);
+}
+module_exit(ad5398_exit);
+
+MODULE_DESCRIPTION("AD5398 and AD5821 current regulator driver");
+MODULE_AUTHOR("Sonic Zhang");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("i2c:ad5398-regulator");