regulator: add userspace-consumer driver

The userspace-consumer driver allows control of voltage and current
regulator state from userspace. This is required for fine-grained
power management of devices that are completely controller by userspace
applications, e.g. a GPS transciever connected to a serial port.

Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 707da4d..5bec17c 100644 (file)
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -47,6 +47,16 @@ config REGULATOR_VIRTUAL_CONSUMER
 
           If unsure, say no.
 
+config REGULATOR_USERSPACE_CONSUMER
+       tristate "Userspace regulator consumer support"
+       default n
+       help
+         There are some classes of devices that are controlled entirely
+         from user space. Usersapce consumer driver provides ability to
+         control power supplies for such devices.
+
+          If unsure, say no.
+
 config REGULATOR_BQ24022
        tristate "TI bq24022 Dual Input 1-Cell Li-Ion Charger IC"
        default n

diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 1d7de87..faf7bcc 100644 (file)
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -6,6 +6,7 @@
 obj-$(CONFIG_REGULATOR) += core.o
 obj-$(CONFIG_REGULATOR_FIXED_VOLTAGE) += fixed.o
 obj-$(CONFIG_REGULATOR_VIRTUAL_CONSUMER) += virtual.o
+obj-$(CONFIG_REGULATOR_USERSPACE_CONSUMER) += userspace-consumer.o
 
 obj-$(CONFIG_REGULATOR_BQ24022) += bq24022.o
 obj-$(CONFIG_REGULATOR_MAX1586) += max1586.o

diff --git a/drivers/regulator/userspace-consumer.c b/drivers/regulator/userspace-consumer.c
new file mode 100644 (file)
index 0000000..71fcf9d
--- /dev/null
+++ b/drivers/regulator/userspace-consumer.c
@@ -0,0 +1,200 @@
+/*
+ * userspace-consumer.c
+ *
+ * Copyright 2009 CompuLab, Ltd.
+ *
+ * Author: Mike Rapoport <mike@compulab.co.il>
+ *
+ * Based of virtual consumer driver:
+ *   Copyright 2008 Wolfson Microelectronics PLC.
+ *   Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+ *
+ * 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.
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/regulator/userspace-consumer.h>
+
+struct userspace_consumer_data {
+       const char *name;
+
+       struct mutex lock;
+       bool enabled;
+
+       int num_supplies;
+       struct regulator_bulk_data *supplies;
+};
+
+static ssize_t show_name(struct device *dev,
+                         struct device_attribute *attr, char *buf)
+{
+       struct userspace_consumer_data *data = dev_get_drvdata(dev);
+
+       return sprintf(buf, "%s\n", data->name);
+}
+
+static ssize_t show_state(struct device *dev,
+                         struct device_attribute *attr, char *buf)
+{
+       struct userspace_consumer_data *data = dev_get_drvdata(dev);
+
+       if (data->enabled)
+               return sprintf(buf, "enabled\n");
+
+       return sprintf(buf, "disabled\n");
+}
+
+static ssize_t set_state(struct device *dev, struct device_attribute *attr,
+                        const char *buf, size_t count)
+{
+       struct userspace_consumer_data *data = dev_get_drvdata(dev);
+       bool enabled;
+       int ret;
+
+       /*
+        * sysfs_streq() doesn't need the \n's, but we add them so the strings
+        * will be shared with show_state(), above.
+        */
+       if (sysfs_streq(buf, "enabled\n") || sysfs_streq(buf, "1"))
+               enabled = true;
+       else if (sysfs_streq(buf, "disabled\n") || sysfs_streq(buf, "0"))
+               enabled = false;
+       else {
+               dev_err(dev, "Configuring invalid mode\n");
+               return count;
+       }
+
+       mutex_lock(&data->lock);
+       if (enabled != data->enabled) {
+               if (enabled)
+                       ret = regulator_bulk_enable(data->num_supplies,
+                                                   data->supplies);
+               else
+                       ret = regulator_bulk_disable(data->num_supplies,
+                                                    data->supplies);
+
+               if (ret == 0)
+                       data->enabled = enabled;
+               else
+                       dev_err(dev, "Failed to configure state: %d\n", ret);
+       }
+       mutex_unlock(&data->lock);
+
+       return count;
+}
+
+static DEVICE_ATTR(name, 0444, show_name, NULL);
+static DEVICE_ATTR(state, 0644, show_state, set_state);
+
+static struct device_attribute *attributes[] = {
+       &dev_attr_name,
+       &dev_attr_state,
+};
+
+static int regulator_userspace_consumer_probe(struct platform_device *pdev)
+{
+       struct regulator_userspace_consumer_data *pdata;
+       struct userspace_consumer_data *drvdata;
+       int ret, i;
+
+       pdata = pdev->dev.platform_data;
+       if (!pdata)
+               return -EINVAL;
+
+       drvdata = kzalloc(sizeof(struct userspace_consumer_data), GFP_KERNEL);
+       if (drvdata == NULL)
+               return -ENOMEM;
+
+       drvdata->name = pdata->name;
+       drvdata->num_supplies = pdata->num_supplies;
+       drvdata->supplies = pdata->supplies;
+
+       mutex_init(&drvdata->lock);
+
+       ret = regulator_bulk_get(&pdev->dev, drvdata->num_supplies,
+                                drvdata->supplies);
+       if (ret) {
+               dev_err(&pdev->dev, "Failed to get supplies: %d\n", ret);
+               goto err_alloc_supplies;
+       }
+
+       for (i = 0; i < ARRAY_SIZE(attributes); i++) {
+               ret = device_create_file(&pdev->dev, attributes[i]);
+               if (ret != 0)
+                       goto err_create_attrs;
+       }
+
+       if (pdata->init_on)
+               ret = regulator_bulk_enable(drvdata->num_supplies,
+                                           drvdata->supplies);
+
+       drvdata->enabled = pdata->init_on;
+
+       if (ret) {
+               dev_err(&pdev->dev, "Failed to set initial state: %d\n", ret);
+               goto err_create_attrs;
+       }
+
+       platform_set_drvdata(pdev, drvdata);
+
+       return 0;
+
+err_create_attrs:
+       for (i = 0; i < ARRAY_SIZE(attributes); i++)
+               device_remove_file(&pdev->dev, attributes[i]);
+
+       regulator_bulk_free(drvdata->num_supplies, drvdata->supplies);
+
+err_alloc_supplies:
+       kfree(drvdata);
+       return ret;
+}
+
+static int regulator_userspace_consumer_remove(struct platform_device *pdev)
+{
+       struct userspace_consumer_data *data = platform_get_drvdata(pdev);
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(attributes); i++)
+               device_remove_file(&pdev->dev, attributes[i]);
+
+       if (data->enabled)
+               regulator_bulk_disable(data->num_supplies, data->supplies);
+
+       regulator_bulk_free(data->num_supplies, data->supplies);
+       kfree(data);
+
+       return 0;
+}
+
+static struct platform_driver regulator_userspace_consumer_driver = {
+       .probe          = regulator_userspace_consumer_probe,
+       .remove         = regulator_userspace_consumer_remove,
+       .driver         = {
+               .name           = "reg-userspace-consumer",
+       },
+};
+
+
+static int __init regulator_userspace_consumer_init(void)
+{
+       return platform_driver_register(&regulator_userspace_consumer_driver);
+}
+module_init(regulator_userspace_consumer_init);
+
+static void __exit regulator_userspace_consumer_exit(void)
+{
+       platform_driver_unregister(&regulator_userspace_consumer_driver);
+}
+module_exit(regulator_userspace_consumer_exit);
+
+MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
+MODULE_DESCRIPTION("Userspace consumer for voltage and current regulators");
+MODULE_LICENSE("GPL");

diff --git a/include/linux/regulator/userspace-consumer.h b/include/linux/regulator/userspace-consumer.h
new file mode 100644 (file)
index 0000000..b4554ce
--- /dev/null
+++ b/include/linux/regulator/userspace-consumer.h
@@ -0,0 +1,25 @@
+#ifndef __REGULATOR_PLATFORM_CONSUMER_H_
+#define __REGULATOR_PLATFORM_CONSUMER_H_
+
+struct regulator_consumer_supply;
+
+/**
+ * struct regulator_userspace_consumer_data - line consumer
+ * initialisation data.
+ *
+ * @name: Name for the consumer line
+ * @num_supplies: Number of supplies feeding the line
+ * @supplies: Supplies configuration.
+ * @init_on: Set if the regulators supplying the line should be
+ *           enabled during initialisation
+ */
+struct regulator_userspace_consumer_data {
+       const char *name;
+
+       int num_supplies;
+       struct regulator_bulk_data *supplies;
+
+       bool init_on;
+};
+
+#endif /* __REGULATOR_PLATFORM_CONSUMER_H_ */