Signed-off-by: Rodolfo Giometti <[email protected]>
Acked-by: Raffaele Recalcati <[email protected]>
Acked-by: Enrico Valtolina <[email protected]>
---
drivers/regulator/Kconfig | 7 ++
drivers/regulator/Makefile | 1 +
drivers/regulator/ds1803.c | 201 ++++++++++++++++++++++++++++++++++++++
include/linux/regulator/ds1803.h | 41 ++++++++
4 files changed, 250 insertions(+), 0 deletions(-)
create mode 100644 drivers/regulator/ds1803.c
create mode 100644 include/linux/regulator/ds1803.h
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 04f2e08..ebaf09b 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -201,5 +201,12 @@ config REGULATOR_88PM8607
help
This driver supports 88PM8607 voltage regulator chips.
+config REGULATOR_DS1803
+ tristate "Dallas Maxim DS1803 addressable dual digital potentiometer"
+ depends on I2C
+ help
+ Say Y here to support the dual digital potentiometer on
+ Dallas Maxim DS1803
+
endif
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 4e7feec..c0fe050 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -31,5 +31,6 @@ obj-$(CONFIG_REGULATOR_AB3100) += ab3100.o
obj-$(CONFIG_REGULATOR_TPS65023) += tps65023-regulator.o
obj-$(CONFIG_REGULATOR_TPS6507X) += tps6507x-regulator.o
obj-$(CONFIG_REGULATOR_88PM8607) += 88pm8607.o
+obj-$(CONFIG_REGULATOR_DS1803) += ds1803.o
ccflags-$(CONFIG_REGULATOR_DEBUG) += -DDEBUG
diff --git a/drivers/regulator/ds1803.c b/drivers/regulator/ds1803.c
new file mode 100644
index 0000000..84719c9
--- /dev/null
+++ b/drivers/regulator/ds1803.c
@@ -0,0 +1,201 @@
+/*
+ * ds1803.c -- Voltage regulation for the DS1803
+ *
+ * Copyright (C) 2009 Rodolfo Giometti <[email protected]>
+ * Copyright (C) 2009 Bticino S.p.A. <[email protected]>
+ *
+ * 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/ds1803.h>
+
+struct ds1803_data {
+ struct i2c_client *client;
+ struct regulator_dev *rdev;
+
+ unsigned int min_uV; /* voltage for selector value 0 */
+ unsigned int max_uV; /* voltage for selector value 255 */
+ unsigned int init_uV; /* initial voltage */
+};
+
+/*
+ * Low level functions
+ */
+
+static u8 ds1803_write_pot_lut[] = { 0xa9, 0xaa, /* both not supported */ };
+
+static int ds1803_set_voltage(struct regulator_dev *rdev,
+ int min_uV, int max_uV)
+{
+ struct ds1803_data *ds1803 = rdev_get_drvdata(rdev);
+ struct i2c_client *client = ds1803->client;
+ unsigned int id = rdev_get_id(rdev);
+ int val;
+ u8 buf[2] = { ds1803_write_pot_lut[id], 0 };
+ struct i2c_msg msgs[1] = {
+ { client->addr , 0, 2, buf },
+ };
+ int ret;
+
+ val = (min_uV - ds1803->min_uV) * 255 / ds1803->max_uV;
+
+ if (val < 0 || val > 255)
+ return -EINVAL;
+ buf[1] = val;
+
+ ret = i2c_transfer(client->adapter, &msgs[0], 1);
+ if (ret != 1) {
+ dev_err(&client->dev, "%s: write error\n", __func__);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int ds1803_list_voltage(struct regulator_dev *rdev, unsigned index)
+{
+ struct ds1803_data *ds1803 = rdev_get_drvdata(rdev);
+
+ return (ds1803->max_uV - ds1803->min_uV) * index / 255
+ + ds1803->min_uV;
+}
+
+/*
+ * Regulator methods
+ */
+
+static struct regulator_ops ds1803_voltage_ops = {
+ .set_voltage = ds1803_set_voltage,
+ .list_voltage = ds1803_list_voltage,
+};
+
+static char *ds1803_names[] = {
+ [DS1803_100K] = "trimmer_100k",
+ [DS1803_50K] = "trimmer_50k",
+ [DS1803_10K] = "trimmer_10k",
+};
+
+static struct regulator_desc ds1803_reg[] = {
+ {
+ .type = REGULATOR_VOLTAGE,
+ .id = 0,
+ .n_voltages = 256,
+ .ops = &ds1803_voltage_ops,
+ .owner = THIS_MODULE,
+ },
+ {
+ .type = REGULATOR_VOLTAGE,
+ .id = 1,
+ .n_voltages = 256,
+ .ops = &ds1803_voltage_ops,
+ .owner = THIS_MODULE,
+ },
+};
+
+static int ds1803_i2c_probe(struct i2c_client *client,
+ const struct i2c_device_id *i2c_id)
+{
+ struct ds1803_platform_data *pdata = client->dev.platform_data;
+ struct ds1803_data *ds1803;
+ int i, ret = -ENOMEM;
+
+ ds1803 = kzalloc(sizeof(struct ds1803_data) * 2, GFP_KERNEL);
+ if (!ds1803)
+ goto out;
+
+ for (i = 0; i < 2; i++) {
+ ds1803[i].client = client;
+
+ /* No init_data -> no regulation */
+ if (!pdata->subdev[i].init)
+ continue;
+
+ /* Set chip's name according to user supplied type */
+ ds1803_reg[i].name = ds1803_names[pdata->type];
+
+ ds1803[i].min_uV = pdata->subdev[i].min_uV;
+ ds1803[i].max_uV = pdata->subdev[i].max_uV;
+ ds1803[i].rdev = regulator_register(&ds1803_reg[i],
+ &client->dev,
+ pdata->subdev[i].init, &ds1803[i]);
+ if (IS_ERR(ds1803[i].rdev)) {
+ dev_err(&client->dev,
+ "failed to register regulator %d\n", i);
+ goto err;
+ }
+ }
+
+ i2c_set_clientdata(client, ds1803);
+ dev_info(&client->dev, "DS1803 regulator driver loaded\n");
+ return 0;
+
+err:
+ while (--i >= 0)
+ regulator_unregister(ds1803[i].rdev);
+ kfree(ds1803);
+out:
+ return ret;
+}
+
+static int ds1803_i2c_remove(struct i2c_client *client)
+{
+ struct ds1803_data *ds1803 = i2c_get_clientdata(client);
+ int i;
+
+ for (i = 0; i < 2; i++)
+ if (ds1803[i].rdev)
+ regulator_unregister(ds1803[i].rdev);
+ kfree(ds1803);
+ i2c_set_clientdata(client, NULL);
+
+ return 0;
+}
+
+static const struct i2c_device_id ds1803_id[] = {
+ { "ds1803", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ds1803_id);
+
+static struct i2c_driver ds1803_i2c_driver = {
+ .probe = ds1803_i2c_probe,
+ .remove = ds1803_i2c_remove,
+ .driver = {
+ .name = "ds1803",
+ },
+ .id_table = ds1803_id,
+};
+
+static int __init ds1803_i2c_init(void)
+{
+ return i2c_add_driver(&ds1803_i2c_driver);
+}
+subsys_initcall(ds1803_i2c_init);
+
+static void __exit ds1803_i2c_exit(void)
+{
+ i2c_del_driver(&ds1803_i2c_driver);
+}
+module_exit(ds1803_i2c_exit);
+
+/* Module information */
+MODULE_DESCRIPTION("DS1803 voltage regulator driver");
+MODULE_AUTHOR("Rodolfo Giometti <[email protected]>");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/regulator/ds1803.h b/include/linux/regulator/ds1803.h
new file mode 100644
index 0000000..6bce0ec
--- /dev/null
+++ b/include/linux/regulator/ds1803.h
@@ -0,0 +1,41 @@
+/*
+ * ds1803.h -- Voltage regulation for the DS1803
+ *
+ * Copyright (C) 2009 Rodolfo Giometti <[email protected]>
+ * Copyright (C) 2009 Bticino S.p.A. <[email protected]>
+ *
+ * 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 version 2.
+ *
+ * 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
+ */
+
+#ifndef _DS1803_H
+#define _DS1803_H
+
+#include <linux/regulator/machine.h>
+
+enum ds1803_type {
+ DS1803_100K,
+ DS1803_50K,
+ DS1803_10K,
+};
+
+struct ds1803_platform_data {
+ enum ds1803_type type;
+ struct {
+ unsigned int min_uV;
+ unsigned int max_uV;
+ struct regulator_init_data *init;
+ } subdev[2];
+};
+
+#endif /* _DS1803_H */
--
1.6.3.3
On Thu, Apr 01, 2010 at 01:23:32PM +0200, Rodolfo Giometti wrote:
This looks good, a few nitpicky things below.
> +config REGULATOR_DS1803
> + tristate "Dallas Maxim DS1803 addressable dual digital potentiometer"
> + depends on I2C
> + help
> + Say Y here to support the dual digital potentiometer on
> + Dallas Maxim DS1803
> +
Oh, wow. A pot as a voltage regulator... :)
> +struct ds1803_data {
> + struct i2c_client *client;
> + struct regulator_dev *rdev;
> +
> + unsigned int min_uV; /* voltage for selector value 0 */
> + unsigned int max_uV; /* voltage for selector value 255 */
> + unsigned int init_uV; /* initial voltage */
Given that you don't support get_voltage() or otherwise reference
init_uV it seems as well to just drop that for now.
> +static u8 ds1803_write_pot_lut[] = { 0xa9, 0xaa, /* both not supported */ };
Both what? Since you don't seem to reference this I guess it could just
be dropped...
> +static int ds1803_list_voltage(struct regulator_dev *rdev, unsigned index)
> +{
> + struct ds1803_data *ds1803 = rdev_get_drvdata(rdev);
> +
> + return (ds1803->max_uV - ds1803->min_uV) * index / 255
> + + ds1803->min_uV;
> +}
I think I'd like more brackets in this calculation for clarity that the
operator precedence is OK.
> + /* Set chip's name according to user supplied type */
> + ds1803_reg[i].name = ds1803_names[pdata->type];
Perhaps just let the user write in something they feel like, or use a
constant string for the chip? The type doesn't seem to be used
otherwise so I can see the data ending up wrong and misleading folks.
> +enum ds1803_type {
> + DS1803_100K,
> + DS1803_50K,
> + DS1803_10K,
> +};
If you are going to keep these assign a value to the first item so you
don't end up with 0 as a valid type, or make the 0 type be "unspecified"
or something. That way platform data that's left initialised to zero
can be distinguished from something that someone deliberately set.