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authorRobert Jarzmik <robert.jarzmik@free.fr>2009-04-23 20:10:43 +0200
committerLiam Girdwood <lrg@slimlogic.co.uk>2009-06-15 11:18:22 +0100
commit55f4fa4e33e90c6b25b4c8ed038392a73b654fef (patch)
tree59e9c50090ca6f2bc5ed1a743c0521560c77fcfa /drivers/regulator/max1586.c
parent45e3e1935e2857c54783291107d33323b3ef33c8 (diff)
Maxim 1586 regulator driver
The Maxim 1586 regulator is a voltage regulator with 2 voltage outputs, specially suitable for Marvell PXA chips. One output is in the range of required VCC_CORE by the PXA27x chips, the other in the VCC_USIM required as well by PXA27x chips. The chip is controlled through the I2C bus. Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
Diffstat (limited to 'drivers/regulator/max1586.c')
-rw-r--r--drivers/regulator/max1586.c249
1 files changed, 249 insertions, 0 deletions
diff --git a/drivers/regulator/max1586.c b/drivers/regulator/max1586.c
new file mode 100644
index 00000000000..bbbb55fcfe8
--- /dev/null
+++ b/drivers/regulator/max1586.c
@@ -0,0 +1,249 @@
+/*
+ * max1586.c -- Voltage and current regulation for the Maxim 1586
+ *
+ * Copyright (C) 2008 Robert Jarzmik
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/max1586.h>
+
+#define MAX1586_V3_MAX_VSEL 31
+#define MAX1586_V6_MAX_VSEL 3
+
+#define MAX1586_V3_MIN_UV 700000
+#define MAX1586_V3_MAX_UV 1475000
+#define MAX1586_V3_STEP_UV 25000
+
+#define MAX1586_V6_MIN_UV 0
+#define MAX1586_V6_MAX_UV 3000000
+
+#define I2C_V3_SELECT (0 << 5)
+#define I2C_V6_SELECT (1 << 5)
+
+/*
+ * V3 voltage
+ * On I2C bus, sending a "x" byte to the max1586 means :
+ * set V3 to 0.700V + (x & 0x1f) * 0.025V
+ */
+static int max1586_v3_calc_voltage(unsigned selector)
+{
+ return MAX1586_V3_MIN_UV + (MAX1586_V3_STEP_UV * selector);
+}
+
+static int max1586_v3_set(struct regulator_dev *rdev, int min_uV, int max_uV)
+{
+ struct i2c_client *client = rdev_get_drvdata(rdev);
+ unsigned selector;
+ u8 v3_prog;
+
+ if (min_uV < MAX1586_V3_MIN_UV || min_uV > MAX1586_V3_MAX_UV)
+ return -EINVAL;
+ if (max_uV < MAX1586_V3_MIN_UV || max_uV > MAX1586_V3_MAX_UV)
+ return -EINVAL;
+
+ selector = (min_uV - MAX1586_V3_MIN_UV) / MAX1586_V3_STEP_UV;
+ if (max1586_v3_calc_voltage(selector) > max_uV)
+ return -EINVAL;
+
+ dev_dbg(&client->dev, "changing voltage v3 to %dmv\n",
+ max1586_v3_calc_voltage(selector) / 1000);
+
+ v3_prog = I2C_V3_SELECT | (u8) selector;
+ return i2c_smbus_write_byte(client, v3_prog);
+}
+
+static int max1586_v3_list(struct regulator_dev *rdev, unsigned selector)
+{
+ if (selector > MAX1586_V3_MAX_VSEL)
+ return -EINVAL;
+ return max1586_v3_calc_voltage(selector);
+}
+
+/*
+ * V6 voltage
+ * On I2C bus, sending a "x" byte to the max1586 means :
+ * set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3)
+ * As regulator framework doesn't accept voltages to be 0V, we use 1uV.
+ */
+static int max1586_v6_calc_voltage(unsigned selector)
+{
+ static int voltages_uv[] = { 1, 1800000, 2500000, 3000000 };
+
+ return voltages_uv[selector];
+}
+
+static int max1586_v6_set(struct regulator_dev *rdev, int min_uV, int max_uV)
+{
+ struct i2c_client *client = rdev_get_drvdata(rdev);
+ unsigned selector;
+ u8 v6_prog;
+
+ if (min_uV < MAX1586_V6_MIN_UV || min_uV > MAX1586_V6_MAX_UV)
+ return -EINVAL;
+ if (max_uV < MAX1586_V6_MIN_UV || max_uV > MAX1586_V6_MAX_UV)
+ return -EINVAL;
+
+ if (min_uV >= 3000000)
+ selector = 3;
+ if (min_uV < 3000000)
+ selector = 2;
+ if (min_uV < 2500000)
+ selector = 1;
+ if (min_uV < 1800000)
+ selector = 0;
+
+ if (max1586_v6_calc_voltage(selector) > max_uV)
+ return -EINVAL;
+
+ dev_dbg(&client->dev, "changing voltage v6 to %dmv\n",
+ max1586_v6_calc_voltage(selector) / 1000);
+
+ v6_prog = I2C_V6_SELECT | (u8) selector;
+ return i2c_smbus_write_byte(client, v6_prog);
+}
+
+static int max1586_v6_list(struct regulator_dev *rdev, unsigned selector)
+{
+ if (selector > MAX1586_V6_MAX_VSEL)
+ return -EINVAL;
+ return max1586_v6_calc_voltage(selector);
+}
+
+/*
+ * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back
+ * the set up value.
+ */
+static struct regulator_ops max1586_v3_ops = {
+ .set_voltage = max1586_v3_set,
+ .list_voltage = max1586_v3_list,
+};
+
+static struct regulator_ops max1586_v6_ops = {
+ .set_voltage = max1586_v6_set,
+ .list_voltage = max1586_v6_list,
+};
+
+static struct regulator_desc max1586_reg[] = {
+ {
+ .name = "Output_V3",
+ .id = MAX1586_V3,
+ .ops = &max1586_v3_ops,
+ .type = REGULATOR_VOLTAGE,
+ .n_voltages = MAX1586_V3_MAX_VSEL + 1,
+ .owner = THIS_MODULE,
+ },
+ {
+ .name = "Output_V6",
+ .id = MAX1586_V6,
+ .ops = &max1586_v6_ops,
+ .type = REGULATOR_VOLTAGE,
+ .n_voltages = MAX1586_V6_MAX_VSEL + 1,
+ .owner = THIS_MODULE,
+ },
+};
+
+static int max1586_pmic_probe(struct i2c_client *client,
+ const struct i2c_device_id *i2c_id)
+{
+ struct regulator_dev **rdev;
+ struct max1586_platform_data *pdata = client->dev.platform_data;
+ int i, id, ret = 0;
+
+ rdev = kzalloc(sizeof(struct regulator_dev *) * (MAX1586_V6 + 1),
+ GFP_KERNEL);
+ if (!rdev)
+ return -ENOMEM;
+
+ ret = -EINVAL;
+ for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {
+ id = pdata->subdevs[i].id;
+ if (!pdata->subdevs[i].platform_data)
+ continue;
+ if (id < MAX1586_V3 || id > MAX1586_V6) {
+ dev_err(&client->dev, "invalid regulator id %d\n", id);
+ goto err;
+ }
+ rdev[i] = regulator_register(&max1586_reg[id], &client->dev,
+ pdata->subdevs[i].platform_data,
+ client);
+ if (IS_ERR(rdev[i])) {
+ ret = PTR_ERR(rdev[i]);
+ dev_err(&client->dev, "failed to register %s\n",
+ max1586_reg[id].name);
+ goto err;
+ }
+ }
+
+ i2c_set_clientdata(client, rdev);
+ dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n");
+ return 0;
+
+err:
+ while (--i >= 0)
+ regulator_unregister(rdev[i]);
+ kfree(rdev);
+ return ret;
+}
+
+static int max1586_pmic_remove(struct i2c_client *client)
+{
+ struct regulator_dev **rdev = i2c_get_clientdata(client);
+ int i;
+
+ for (i = 0; i <= MAX1586_V6; i++)
+ if (rdev[i])
+ regulator_unregister(rdev[i]);
+ kfree(rdev);
+ i2c_set_clientdata(client, NULL);
+
+ return 0;
+}
+
+static const struct i2c_device_id max1586_id[] = {
+ { "max1586", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, max1586_id);
+
+static struct i2c_driver max1586_pmic_driver = {
+ .probe = max1586_pmic_probe,
+ .remove = max1586_pmic_remove,
+ .driver = {
+ .name = "max1586",
+ },
+ .id_table = max1586_id,
+};
+
+static int __init max1586_pmic_init(void)
+{
+ return i2c_add_driver(&max1586_pmic_driver);
+}
+subsys_initcall(max1586_pmic_init);
+
+static void __exit max1586_pmic_exit(void)
+{
+ i2c_del_driver(&max1586_pmic_driver);
+}
+module_exit(max1586_pmic_exit);
+
+/* Module information */
+MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver");
+MODULE_AUTHOR("Robert Jarzmik");
+MODULE_LICENSE("GPL");