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authorMike Rapoport <mike@compulab.co.il>2009-04-26 17:49:39 +0400
committerLiam Girdwood <lrg@slimlogic.co.uk>2009-06-15 14:18:22 +0400
commit1d98cccf7f8b944ba4ea56d14bbb7c2eeee59bfe (patch)
tree079c8db0e879dbddcec7658dee610ade43d86c67 /drivers/regulator/userspace-consumer.c
parent55f4fa4e33e90c6b25b4c8ed038392a73b654fef (diff)
downloadlinux-1d98cccf7f8b944ba4ea56d14bbb7c2eeee59bfe.tar.xz
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>
Diffstat (limited to 'drivers/regulator/userspace-consumer.c')
-rw-r--r--drivers/regulator/userspace-consumer.c200
1 files changed, 200 insertions, 0 deletions
diff --git a/drivers/regulator/userspace-consumer.c b/drivers/regulator/userspace-consumer.c
new file mode 100644
index 000000000000..71fcf9df00f6
--- /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");