diff options
Diffstat (limited to 'drivers/regulator/userspace-consumer.c')
| -rw-r--r-- | drivers/regulator/userspace-consumer.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/drivers/regulator/userspace-consumer.c b/drivers/regulator/userspace-consumer.c new file mode 100644 index 000000000..8ca286647 --- /dev/null +++ b/drivers/regulator/userspace-consumer.c @@ -0,0 +1,181 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * 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> + */ + +#include <linux/err.h> +#include <linux/mutex.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/regulator/consumer.h> +#include <linux/regulator/userspace-consumer.h> +#include <linux/slab.h> + +struct userspace_consumer_data { + const char *name; + + struct mutex lock; + bool enabled; + + int num_supplies; + struct regulator_bulk_data *supplies; +}; + +static ssize_t name_show(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 state_show(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 state_store(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_RO(name); +static DEVICE_ATTR_RW(state); + +static struct attribute *attributes[] = { + &dev_attr_name.attr, + &dev_attr_state.attr, + NULL, +}; + +static const struct attribute_group attr_group = { + .attrs = attributes, +}; + +static int regulator_userspace_consumer_probe(struct platform_device *pdev) +{ + struct regulator_userspace_consumer_data *pdata; + struct userspace_consumer_data *drvdata; + int ret; + + pdata = dev_get_platdata(&pdev->dev); + if (!pdata) + return -EINVAL; + + drvdata = devm_kzalloc(&pdev->dev, + 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 = devm_regulator_bulk_get(&pdev->dev, drvdata->num_supplies, + drvdata->supplies); + if (ret) { + dev_err(&pdev->dev, "Failed to get supplies: %d\n", ret); + return ret; + } + + ret = sysfs_create_group(&pdev->dev.kobj, &attr_group); + if (ret != 0) + return ret; + + if (pdata->init_on) { + ret = regulator_bulk_enable(drvdata->num_supplies, + drvdata->supplies); + if (ret) { + dev_err(&pdev->dev, + "Failed to set initial state: %d\n", ret); + goto err_enable; + } + } + + drvdata->enabled = pdata->init_on; + platform_set_drvdata(pdev, drvdata); + + return 0; + +err_enable: + sysfs_remove_group(&pdev->dev.kobj, &attr_group); + + return ret; +} + +static int regulator_userspace_consumer_remove(struct platform_device *pdev) +{ + struct userspace_consumer_data *data = platform_get_drvdata(pdev); + + sysfs_remove_group(&pdev->dev.kobj, &attr_group); + + if (data->enabled) + regulator_bulk_disable(data->num_supplies, data->supplies); + + 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", + }, +}; + +module_platform_driver(regulator_userspace_consumer_driver); + +MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>"); +MODULE_DESCRIPTION("Userspace consumer for voltage and current regulators"); +MODULE_LICENSE("GPL"); |