regulator: da9210: New driver

I2C driver for the Dialog DA9210 Multi-phase 12A DC-DC Buck.

Signed-off-by: Steve Twiss <stwiss.opensource@diasemi.com>
Signed-off-by: David Dajun Chen <david.chen@diasemi.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 197 insertions, 0 deletions

diff --git a/drivers/regulator/da9210-regulator.c b/drivers/regulator/da9210-regulator.c
new file mode 100644
index 00000000000..bf492bc7d3d
--- /dev/null
+++ b/drivers/regulator/da9210-regulator.c
@@ -0,0 +1,197 @@
+/*
+ * da9210-regulator.c - Regulator device driver for DA9210
+ * Copyright (C) 2013  Dialog Semiconductor Ltd.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA  02110-1301, USA.
+ */
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regmap.h>
+
+#include "da9210-regulator.h"
+
+struct da9210 {
+	struct regulator_dev *rdev;
+	struct regmap *regmap;
+};
+
+static const struct regmap_config da9210_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static int da9210_set_current_limit(struct regulator_dev *rdev, int min_uA,
+				    int max_uA);
+static int da9210_get_current_limit(struct regulator_dev *rdev);
+
+static struct regulator_ops da9210_buck_ops = {
+	.enable = regulator_enable_regmap,
+	.disable = regulator_disable_regmap,
+	.is_enabled = regulator_is_enabled_regmap,
+	.set_voltage_sel = regulator_set_voltage_sel_regmap,
+	.get_voltage_sel = regulator_get_voltage_sel_regmap,
+	.list_voltage = regulator_list_voltage_linear,
+	.set_current_limit = da9210_set_current_limit,
+	.get_current_limit = da9210_get_current_limit,
+};
+
+/* Default limits measured in millivolts and milliamps */
+#define DA9210_MIN_MV		300
+#define DA9210_MAX_MV		1570
+#define DA9210_STEP_MV		10
+
+/* Current limits for buck (uA) indices corresponds with register values */
+static const int da9210_buck_limits[] = {
+	1600000, 1800000, 2000000, 2200000, 2400000, 2600000, 2800000, 3000000,
+	3200000, 3400000, 3600000, 3800000, 4000000, 4200000, 4400000, 4600000
+};
+
+static const struct regulator_desc da9210_reg = {
+	.name = "DA9210",
+	.id = 0,
+	.ops = &da9210_buck_ops,
+	.type = REGULATOR_VOLTAGE,
+	.n_voltages = ((DA9210_MAX_MV - DA9210_MIN_MV) / DA9210_STEP_MV) + 1,
+	.min_uV = (DA9210_MIN_MV * 1000),
+	.uV_step = (DA9210_STEP_MV * 1000),
+	.vsel_reg = DA9210_REG_VBUCK_A,
+	.vsel_mask = DA9210_VBUCK_MASK,
+	.enable_reg = DA9210_REG_BUCK_CONT,
+	.enable_mask = DA9210_BUCK_EN,
+	.owner = THIS_MODULE,
+};
+
+static int da9210_set_current_limit(struct regulator_dev *rdev, int min_uA,
+				    int max_uA)
+{
+	struct da9210 *chip = rdev_get_drvdata(rdev);
+	unsigned int sel;
+	int i;
+
+	/* search for closest to maximum */
+	for (i = ARRAY_SIZE(da9210_buck_limits)-1; i >= 0; i--) {
+		if (min_uA <= da9210_buck_limits[i] &&
+		    max_uA >= da9210_buck_limits[i]) {
+			sel = i;
+			sel = sel << DA9210_BUCK_ILIM_SHIFT;
+			return regmap_update_bits(chip->regmap,
+						  DA9210_REG_BUCK_ILIM,
+						  DA9210_BUCK_ILIM_MASK, sel);
+		}
+	}
+
+	return -EINVAL;
+}
+
+static int da9210_get_current_limit(struct regulator_dev *rdev)
+{
+	struct da9210 *chip = rdev_get_drvdata(rdev);
+	unsigned int data;
+	unsigned int sel;
+	int ret;
+
+	ret = regmap_read(chip->regmap, DA9210_REG_BUCK_ILIM, &data);
+	if (ret < 0)
+		return ret;
+
+	/* select one of 16 values: 0000 (1600mA) to 1111 (4600mA) */
+	sel = (data & DA9210_BUCK_ILIM_MASK) >> DA9210_BUCK_ILIM_SHIFT;
+
+	return da9210_buck_limits[sel];
+}
+
+/*
+ * I2C driver interface functions
+ */
+static int da9210_i2c_probe(struct i2c_client *i2c,
+			    const struct i2c_device_id *id)
+{
+	struct da9210 *chip;
+	struct da9210_pdata *pdata = i2c->dev.platform_data;
+	struct regulator_dev *rdev = NULL;
+	struct regulator_config config = { };
+	int error;
+
+	chip = devm_kzalloc(&i2c->dev, sizeof(struct da9210), GFP_KERNEL);
+	if (NULL == chip) {
+		dev_err(&i2c->dev,
+			"Cannot kzalloc memory for regulator structure\n");
+		return -ENOMEM;
+	}
+
+	chip->regmap = devm_regmap_init_i2c(i2c, &da9210_regmap_config);
+	if (IS_ERR(chip->regmap)) {
+		error = PTR_ERR(chip->regmap);
+		dev_err(&i2c->dev, "Failed to allocate register map: %d\n",
+			error);
+		return error;
+	}
+
+	config.dev = &i2c->dev;
+	if (pdata)
+		config.init_data = &pdata->da9210_constraints;
+	config.driver_data = chip;
+	config.regmap = chip->regmap;
+
+	rdev = regulator_register(&da9210_reg, &config);
+	if (IS_ERR(rdev)) {
+		dev_err(&i2c->dev, "Failed to register DA9210 regulator\n");
+		return PTR_ERR(rdev);
+	}
+
+	chip->rdev = rdev;
+
+	i2c_set_clientdata(i2c, chip);
+
+	return 0;
+}
+
+static int da9210_i2c_remove(struct i2c_client *i2c)
+{
+	struct da9210 *chip = i2c_get_clientdata(i2c);
+	regulator_unregister(chip->rdev);
+	return 0;
+}
+
+static const struct i2c_device_id da9210_i2c_id[] = {
+	{"da9210", 0},
+	{},
+};
+
+MODULE_DEVICE_TABLE(i2c, da9210_i2c_id);
+
+static struct i2c_driver da9210_regulator_driver = {
+	.driver = {
+		.name = "da9210",
+		.owner = THIS_MODULE,
+	},
+	.probe = da9210_i2c_probe,
+	.remove = da9210_i2c_remove,
+	.id_table = da9210_i2c_id,
+};
+
+module_i2c_driver(da9210_regulator_driver);
+
+MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
+MODULE_DESCRIPTION("Regulator device driver for Dialog DA9210");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("i2c:da9210");