2008-02-20 17:11:35

by Liam Girdwood

Subject: [PATCH 4/6] regulator: regulator core.

This patch provides the regulator framework core. The core also provides a
sysfs interface for userspace information.

Signed-off-by: Liam Girdwood <[email protected]>
---
drivers/regulator/reg-core.c | 1049 ++++++++++++++++++++++++++++++++++++++++++
1 files changed, 1049 insertions(+), 0 deletions(-)
create mode 100644 drivers/regulator/reg-core.c

diff --git a/drivers/regulator/reg-core.c b/drivers/regulator/reg-core.c
new file mode 100644
index 0000000..43610c6
--- /dev/null
+++ b/drivers/regulator/reg-core.c
@@ -0,0 +1,1049 @@
+/*
+ * regulator.c -- Voltage/Current Regulator framework.
+ *
+ * Copyright 2007 Wolfson Microelectronics PLC.
+ *
+ * Author: Liam Girdwood <[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.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/regulator/regulator.h>
+#include <linux/regulator/regulator-drv.h>
+#include <linux/regulator/regulator-platform.h>
+
+#define REGULATOR_VERSION "0.3"
+
+/* We need to undef the current macro (from include/asm/current.h) otherwise
+ * our "current" sysfs entry becomes "(get_current())".
+ */
+#undef current
+
+static DEFINE_MUTEX(list_mutex);
+static LIST_HEAD(regulator_cdevs);
+
+/**
+ * struct regulator_cdev
+ *
+ * Voltage / Current regulator class device. One for each regulator.
+ */
+struct regulator_cdev {
+ struct regulator_desc *desc;
+ int use_count;
+
+ struct list_head list;
+ struct list_head consumer_list;
+ struct blocking_notifier_head notifier;
+ struct mutex mutex;
+ struct module *owner;
+ struct class_device cdev;
+ struct regulation_constraints *constraints;
+ struct regulator_cdev *parent; /* for tree */
+
+ void *reg_data; /* regulator_cdev data */
+ void *vendor; /* regulator_cdev vendor extensions */
+};
+#define to_rcdev(cd) \
+ container_of(cd, struct regulator_cdev, cdev)
+
+/*
+ * struct regulator
+ *
+ * One for each consumer device.
+ */
+struct regulator {
+ struct device *dev;
+ struct list_head list;
+ int uA_load;
+ int uV_required;
+ int enabled;
+ struct device_attribute dev_attr;
+ struct regulator_cdev *rcdev;
+};
+
+static int _regulator_is_enabled(struct regulator_cdev *rcdev);
+static int _regulator_disable(struct regulator_cdev *rcdev);
+static int _regulator_get_voltage(struct regulator_cdev *rcdev);
+static int _regulator_get_current(struct regulator_cdev *rcdev);
+static unsigned int _regulator_get_mode(struct regulator_cdev *rcdev);
+
+static struct regulator *get_regulator_load(struct device *dev)
+{
+ struct regulator *regulator = NULL;
+ struct regulator_cdev *rcdev;
+
+ list_for_each_entry(rcdev, &regulator_cdevs, list) {
+ list_for_each_entry(regulator, &rcdev->consumer_list, list) {
+ if (regulator->dev == dev)
+ return regulator;
+ }
+ }
+ return NULL;
+}
+
+static int regulator_check_voltage(struct regulator_cdev *rcdev, int uV)
+{
+ if (!rcdev->constraints) {
+ printk(KERN_ERR "%s: no constraints for %s\n", __func__,
+ rcdev->desc->name);
+ return -ENODEV;
+ }
+ if (!rcdev->constraints->valid_ops_mask & REGULATOR_CHANGE_VOLTAGE) {
+ printk(KERN_ERR "%s: operation not allowed for %s\n",
+ __func__, rcdev->desc->name);
+ return -EPERM;
+ }
+ if (uV > rcdev->constraints->max_uV ||
+ uV < rcdev->constraints->min_uV) {
+ printk(KERN_ERR "%s: invalid voltage %duV for %s\n",
+ __func__, uV, rcdev->desc->name);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static int regulator_check_current(struct regulator_cdev *rcdev, int uA)
+{
+ if (!rcdev->constraints) {
+ printk(KERN_ERR "%s: no constraints for %s\n", __func__,
+ rcdev->desc->name);
+ return -ENODEV;
+ }
+ if (!rcdev->constraints->valid_ops_mask & REGULATOR_CHANGE_CURRENT) {
+ printk(KERN_ERR "%s: operation not allowed for %s\n",
+ __func__, rcdev->desc->name);
+ return -EPERM;
+ }
+ if (uA > rcdev->constraints->max_uA ||
+ uA < rcdev->constraints->min_uA) {
+ printk(KERN_ERR "%s: invalid current %duA for %s\n",
+ __func__, uA, rcdev->desc->name);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static int regulator_check_mode(struct regulator_cdev *rcdev, int mode)
+{
+ if (!rcdev->constraints) {
+ printk(KERN_ERR "%s: no constraints for %s\n", __func__,
+ rcdev->desc->name);
+ return -ENODEV;
+ }
+ if (!rcdev->constraints->valid_ops_mask & REGULATOR_CHANGE_MODE) {
+ printk(KERN_ERR "%s: operation not allowed for %s\n",
+ __func__, rcdev->desc->name);
+ return -EPERM;
+ }
+ if (!rcdev->constraints->valid_modes_mask & mode) {
+ printk(KERN_ERR "%s: invalid mode %x for %s\n",
+ __func__, mode, rcdev->desc->name);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static int regulator_check_drms(struct regulator_cdev *rcdev)
+{
+ if (!rcdev->constraints) {
+ printk(KERN_ERR "%s: no constraints for %s\n", __func__,
+ rcdev->desc->name);
+ return -ENODEV;
+ }
+ if (!rcdev->constraints->valid_ops_mask & REGULATOR_CHANGE_DRMS) {
+ printk(KERN_ERR "%s: operation not allowed for %s\n",
+ __func__, rcdev->desc->name);
+ return -EPERM;
+ }
+ return 0;
+}
+
+static ssize_t dev_load_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct regulator *regulator;
+
+ regulator = get_regulator_load(dev);
+ if (regulator == NULL)
+ return 0;
+
+ return sprintf(buf, "%d\n", regulator->uA_load);
+}
+
+static ssize_t regulator_uV_show(struct class_device *cdev, char *buf)
+{
+ struct regulator_cdev *rcdev = to_rcdev(cdev);
+
+ return sprintf(buf, "%d\n", _regulator_get_voltage(rcdev));
+}
+
+static ssize_t regulator_uA_show(struct class_device *cdev, char *buf)
+{
+ struct regulator_cdev *rcdev = to_rcdev(cdev);
+
+ return sprintf(buf, "%d\n", _regulator_get_current(rcdev));
+}
+
+static ssize_t regulator_mode_show(struct class_device *cdev, char *buf)
+{
+ struct regulator_cdev *rcdev = to_rcdev(cdev);
+ int mode = _regulator_get_mode(rcdev);
+
+ switch (mode) {
+ case REGULATOR_MODE_FAST:
+ return sprintf(buf, "fast\n");
+ case REGULATOR_MODE_NORMAL:
+ return sprintf(buf, "normal\n");
+ case REGULATOR_MODE_IDLE:
+ return sprintf(buf, "idle\n");
+ case REGULATOR_MODE_STANDBY:
+ return sprintf(buf, "standby\n");
+ }
+ return sprintf(buf, "unknown\n");
+}
+
+static ssize_t regulator_state_show(struct class_device *cdev, char *buf)
+{
+ struct regulator_cdev *rcdev = to_rcdev(cdev);
+ int state = _regulator_is_enabled(rcdev);
+
+ if (state > 0)
+ return sprintf(buf, "enabled\n");
+ else if (state == 0)
+ return sprintf(buf, "disabled\n");
+ else
+ return sprintf(buf, "unknown\n");
+}
+
+static ssize_t regulator_constraint_uA_show(struct class_device *cdev,
+ char *buf)
+{
+ struct regulator_cdev *rcdev = to_rcdev(cdev);
+
+ if (!rcdev->constraints)
+ return sprintf(buf, "constraints not defined\n");
+
+ return sprintf (buf, "%d %d\n", rcdev->constraints->min_uA,
+ rcdev->constraints->max_uA);
+}
+
+static ssize_t regulator_constraint_uV_show(struct class_device *cdev,
+ char *buf)
+{
+ struct regulator_cdev *rcdev = to_rcdev(cdev);
+
+ if (!rcdev->constraints)
+ return sprintf(buf, "constraints not defined\n");
+
+ return sprintf (buf, "%d %d\n", rcdev->constraints->min_uV,
+ rcdev->constraints->max_uV);
+}
+
+static ssize_t regulator_constraint_modes_show(struct class_device *cdev,
+ char *buf)
+{
+ struct regulator_cdev *rcdev = to_rcdev(cdev);
+ int count = 0;
+
+ if (!rcdev->constraints)
+ return sprintf(buf, "constraints not defined\n");
+
+ if (rcdev->constraints->valid_modes_mask & REGULATOR_MODE_FAST)
+ count = sprintf (buf, "fast ");
+ if (rcdev->constraints->valid_modes_mask & REGULATOR_MODE_NORMAL)
+ count += sprintf (buf + count, "normal ");
+ if (rcdev->constraints->valid_modes_mask & REGULATOR_MODE_IDLE)
+ count += sprintf (buf + count, "idle ");
+ if (rcdev->constraints->valid_modes_mask & REGULATOR_MODE_STANDBY)
+ count += sprintf (buf + count, "standby");
+ count += sprintf(buf + count, "\n");
+ return count;
+}
+
+static ssize_t regulator_total_dev_load(struct class_device *cdev, char *buf)
+{
+ struct regulator_cdev *rcdev = to_rcdev(cdev);
+ struct regulator *regulator;
+ int uA = 0;
+
+ list_for_each_entry(regulator, &rcdev->consumer_list, list)
+ uA =+ regulator->uA_load;
+ return sprintf(buf, "%d\n", uA);
+}
+
+static ssize_t regulator_enabled_use_count(struct class_device *cdev,
+ char *buf)
+{
+ struct regulator_cdev *rcdev = to_rcdev(cdev);
+ return sprintf(buf, "%d\n", rcdev->use_count);
+}
+
+static ssize_t regulator_type_show(struct class_device *cdev, char *buf)
+{
+ struct regulator_cdev *rcdev = to_rcdev(cdev);
+
+ switch (rcdev->desc->type) {
+ case REGULATOR_VOLTAGE:
+ return sprintf(buf, "voltage\n");
+ case REGULATOR_CURRENT:
+ return sprintf(buf, "current\n");
+ }
+ return sprintf(buf, "unknown\n");
+}
+
+static struct class_device_attribute regulator_dev_attrs[] = {
+ __ATTR(voltage, 0444, regulator_uV_show, NULL),
+ __ATTR(current, 0444, regulator_uA_show, NULL),
+ __ATTR(opmode, 0444, regulator_mode_show, NULL),
+ __ATTR(enabled, 0444, regulator_state_show, NULL),
+ __ATTR(voltage_limits, 0444, regulator_constraint_uA_show, NULL),
+ __ATTR(current_limits, 0444, regulator_constraint_uV_show, NULL),
+ __ATTR(valid_opmodes, 0444, regulator_constraint_modes_show, NULL),
+ __ATTR(total_load, 0444, regulator_total_dev_load, NULL),
+ __ATTR(enabled_count, 0444, regulator_enabled_use_count, NULL),
+ __ATTR(type, 0444, regulator_type_show, NULL),
+ __ATTR_NULL,
+};
+
+static void regulator_dev_release(struct class_device *class_dev) {}
+
+struct class regulator_class = {
+ .name = "regulator",
+ .release = regulator_dev_release,
+ .class_dev_attrs = regulator_dev_attrs,
+};
+
+/* find the lowest stable voltage that all enabled clients can operate at */
+static int get_lowest_stable_voltage(struct regulator_cdev *rcdev)
+{
+ struct regulator *regulator;
+ int highest_uV = 0;
+
+ list_for_each_entry(regulator, &rcdev->consumer_list, list) {
+ if (regulator->enabled && regulator->uV_required > highest_uV)
+ highest_uV = regulator->uV_required;
+ }
+ return highest_uV;
+}
+
+/* set the regulator voltage to the lowest possible value that can safely
+ * support all the client devices */
+static int regulator_set_stable_voltage(struct regulator_cdev *rcdev)
+{
+ int ret = 0, uV;
+
+ if (rcdev->desc->type == REGULATOR_VOLTAGE) {
+ uV = get_lowest_stable_voltage(rcdev);
+ if (uV && rcdev->desc->ops->set_voltage)
+ ret = rcdev->desc->ops->set_voltage(rcdev, uV);
+ }
+ return ret;
+}
+
+static void regulator_load_change (struct regulator_cdev *rcdev)
+{
+ struct regulator *sibling;
+ int current_uA = 0, output_uV, input_uV, err;
+ unsigned int mode;
+
+ err = regulator_check_drms(rcdev);
+ if (err < 0 || !rcdev->desc->ops->get_optimum_mode ||
+ !rcdev->desc->ops->get_voltage || !rcdev->desc->ops->set_mode);
+ return;
+
+ /* get output voltage */
+ output_uV = rcdev->desc->ops->get_voltage(rcdev);
+
+ /* get input voltage */
+ if (rcdev->parent && rcdev->parent->desc->ops->get_voltage)
+ input_uV =
+ rcdev->parent->desc->ops->get_voltage(rcdev->parent);
+ else
+ input_uV = rcdev->constraints->input_uV;
+
+ /* calc total requested load */
+ list_for_each_entry(sibling, &rcdev->consumer_list, list)
+ current_uA += sibling->uA_load;
+
+ /* now get the optimum mode for our new total regulator load */
+ mode = rcdev->desc->ops->get_optimum_mode(rcdev, input_uV,
+ output_uV, current_uA);
+
+ /* check the new mode is allowed */
+ err = regulator_check_mode(rcdev, mode);
+ if (err == 0)
+ rcdev->desc->ops->set_mode(rcdev, mode);
+}
+
+static void print_constraints(struct regulator_cdev *rcdev)
+{
+ struct regulation_constraints *constraints = rcdev->constraints;
+ char buf[80];
+ int count;
+
+ if (rcdev->desc->type == REGULATOR_VOLTAGE) {
+ if (constraints->min_uV == constraints->max_uV)
+ count = sprintf(buf, "%d mV ",
+ uV_to_mV(constraints->min_uV));
+ else
+ count = sprintf(buf, "%d <--> %d mV ",
+ uV_to_mV(constraints->min_uV),
+ uV_to_mV(constraints->max_uV));
+ } else {
+ if (constraints->min_uA == constraints->max_uA)
+ count = sprintf(buf, "%d mA ",
+ uA_to_mA(constraints->min_uA));
+ else
+ count = sprintf(buf, "%d <--> %d mA ",
+ uA_to_mA(constraints->min_uA),
+ uA_to_mA(constraints->max_uA));
+ }
+ if (constraints->valid_modes_mask & REGULATOR_MODE_FAST)
+ count += sprintf (buf + count, "fast ");
+ if (constraints->valid_modes_mask & REGULATOR_MODE_NORMAL)
+ count += sprintf (buf + count, "normal ");
+ if (constraints->valid_modes_mask & REGULATOR_MODE_IDLE)
+ count += sprintf (buf + count, "idle ");
+ if (constraints->valid_modes_mask & REGULATOR_MODE_STANDBY)
+ count += sprintf (buf + count, "standby");
+
+ printk(KERN_INFO "regulator: %s: %s\n", rcdev->desc->name, buf);
+}
+
+static struct regulator *create_regulator(struct regulator_cdev *rcdev,
+ struct device *dev)
+{
+ struct regulator *regulator;
+ char buf[32];
+ int err;
+
+ regulator = kzalloc(sizeof(*regulator), GFP_KERNEL);
+ if (regulator == NULL)
+ return NULL;
+
+ regulator->rcdev = rcdev;
+ sprintf(buf, "current_requested-%s", regulator->rcdev->desc->name);
+ list_add(&regulator->list, &rcdev->consumer_list);
+
+ if (dev == NULL)
+ goto out;
+
+ regulator->dev = dev;
+ regulator->dev_attr.attr.name = kstrdup(buf, GFP_KERNEL);
+ if (regulator->dev_attr.attr.name == NULL)
+ goto err_out;
+ regulator->dev_attr.attr.owner = THIS_MODULE;
+ regulator->dev_attr.attr.mode = 0444;
+ regulator->dev_attr.show = dev_load_show;
+ err = device_create_file(dev, &regulator->dev_attr);
+ if (err < 0) {
+ printk(KERN_WARNING "%s: could not add regulator_cdev load"
+ " sysfs\n", __func__);
+ goto err_out;
+ }
+ err = sysfs_create_link(&rcdev->cdev.kobj, &dev->kobj,
+ dev->kobj.name);
+ if (err) {
+ printk(KERN_WARNING
+ "%s: could not add device link %s err %d\n",
+ __func__, dev->kobj.name, err);
+ goto err_out;
+ }
+out:
+ return regulator;
+err_out:
+ kfree(regulator->dev_attr.attr.name);
+ list_del(&regulator->list);
+ kfree(regulator);
+ return NULL;
+}
+
+struct regulator *regulator_get(struct device *dev, const char *id)
+{
+ struct regulator_cdev *rcdev;
+ struct regulator *regulator = ERR_PTR(-ENODEV);
+
+ if (id == NULL)
+ return regulator;
+
+ mutex_lock(&list_mutex);
+ list_for_each_entry(rcdev, &regulator_cdevs, list) {
+ if (strcmp(id, rcdev->desc->name) == 0 &&
+ try_module_get(rcdev->owner)) {
+ goto found;
+ }
+ }
+ printk(KERN_ERR "regulator: Unable to get requested regulator: %s\n",
+ id);
+ mutex_unlock(&list_mutex);
+ return regulator;
+
+found:
+ regulator = create_regulator(rcdev, dev);
+ if (regulator == NULL) {
+ regulator = ERR_PTR(-ENOMEM);
+ module_put(rcdev->owner);
+ }
+
+ mutex_unlock(&list_mutex);
+ return regulator;
+}
+EXPORT_SYMBOL_GPL(regulator_get);
+
+void regulator_put(struct regulator *regulator)
+{
+ struct regulator_cdev *rcdev;
+
+ if (regulator == NULL || IS_ERR(regulator))
+ return;
+
+ rcdev = regulator->rcdev;
+
+ /* remove any sysfs entries */
+ if (regulator->dev) {
+ sysfs_remove_link(&rcdev->cdev.kobj,
+ regulator->dev->kobj.name);
+ device_remove_file(regulator->dev, &regulator->dev_attr);
+ }
+ list_del(&regulator->list);
+ kfree(regulator->dev_attr.attr.name);
+ kfree(regulator);
+
+ module_put(rcdev->owner);
+ mutex_unlock(&list_mutex);
+}
+EXPORT_SYMBOL_GPL(regulator_put);
+
+static int _regulator_enable(struct regulator_cdev *rcdev)
+{
+ int ret = 0;
+
+ /* if the regulator is currently disabled make sure we check
+ * it's parent, mode and required voltage */
+ if (rcdev->use_count == 0) {
+ if (rcdev->parent) {
+ ret = _regulator_enable(rcdev->parent);
+ if (ret < 0) {
+ printk(KERN_ERR "%s: failed to enable %s\n",
+ __func__, rcdev->desc->name);
+ goto out;
+ }
+ }
+ if (rcdev->desc->ops->enable) {
+ ret = regulator_set_stable_voltage(rcdev);
+ if (ret < 0) {
+ printk(KERN_ERR "%s: invalid voltage for %s\n",
+ __func__, rcdev->desc->name);
+ goto out;
+ }
+ regulator_load_change(rcdev);
+ ret = rcdev->desc->ops->enable(rcdev);
+ if (ret < 0) {
+ printk(KERN_ERR "%s: failed to enable %s\n",
+ __func__, rcdev->desc->name);
+ goto out;
+ }
+ }
+ } else {
+ ret = regulator_set_stable_voltage(rcdev);
+ if (ret < 0) {
+ printk(KERN_ERR "%s: invalid voltage for %s\n",
+ __func__, rcdev->desc->name);
+ goto out;
+ }
+ regulator_load_change(rcdev);
+ }
+ rcdev->use_count++;
+out:
+ return ret;
+}
+
+int regulator_enable(struct regulator *regulator)
+{
+ int ret;
+
+ mutex_lock(&regulator->rcdev->mutex);
+ regulator->enabled = 1;
+ ret = _regulator_enable(regulator->rcdev);
+ if (ret < 0)
+ regulator->enabled = 0;
+ mutex_unlock(&regulator->rcdev->mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_enable);
+
+static int _regulator_disable(struct regulator_cdev *rcdev)
+{
+ int ret = 0;
+
+ /* make sure we are the last user before disabling this regulator */
+ if (rcdev->use_count == 1) {
+ if (rcdev->desc->ops->disable) {
+ ret = rcdev->desc->ops->disable(rcdev);
+ if (ret < 0) {
+ printk(KERN_ERR "%s: failed to disable %s\n",
+ __func__, rcdev->desc->name);
+ goto out;
+ }
+ }
+ /* decrease parent ref count and disable if required */
+ if (rcdev->parent)
+ _regulator_disable(rcdev->parent);
+ } else {
+ /* set to next best requested voltage and mode */
+ ret = regulator_set_stable_voltage(rcdev);
+ regulator_load_change(rcdev);
+ }
+ rcdev->use_count--;
+out:
+ if (rcdev->use_count < 0) {
+ printk(KERN_ERR "%s: tried to disable too many times\n",
+ __func__);
+ rcdev->use_count = 0;
+ }
+ return ret;
+}
+
+int regulator_disable(struct regulator *regulator)
+{
+ int ret;
+
+ mutex_lock(&regulator->rcdev->mutex);
+ regulator->enabled = 0;
+ regulator->uA_load = 0;
+ ret = _regulator_disable(regulator->rcdev);
+ if (ret < 0)
+ regulator->enabled = 1;
+ mutex_unlock(&regulator->rcdev->mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_disable);
+
+static int _regulator_is_enabled(struct regulator_cdev *rcdev)
+{
+ int ret;
+
+ mutex_lock(&rcdev->mutex);
+
+ /* sanity check */
+ if (!rcdev->desc->ops->is_enabled) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = rcdev->desc->ops->is_enabled(rcdev);
+out:
+ mutex_unlock(&rcdev->mutex);
+ return ret;
+}
+
+int regulator_is_enabled(struct regulator *regulator)
+{
+ return _regulator_is_enabled(regulator->rcdev);
+}
+EXPORT_SYMBOL_GPL(regulator_is_enabled);
+
+int regulator_set_voltage(struct regulator *regulator, int uV)
+{
+ struct regulator_cdev *rcdev = regulator->rcdev;
+ int ret;
+
+ mutex_lock(&rcdev->mutex);
+
+ /* sanity check */
+ if (!rcdev->desc->ops->set_voltage) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* constraints check */
+ ret = regulator_check_voltage(rcdev, uV);
+ if (ret < 0)
+ goto out;
+ regulator->uV_required = uV;
+
+ /* only set the new voltage if it's all clients can use it */
+ ret = regulator_set_stable_voltage(rcdev);
+out:
+ mutex_unlock(&rcdev->mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_set_voltage);
+
+static int _regulator_get_voltage(struct regulator_cdev *rcdev)
+{
+ int ret;
+
+ mutex_lock(&rcdev->mutex);
+
+ /* sanity check */
+ if (!rcdev->desc->ops->get_voltage) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = rcdev->desc->ops->get_voltage(rcdev);
+out:
+ mutex_unlock(&rcdev->mutex);
+ return ret;
+}
+
+int regulator_get_voltage(struct regulator *regulator)
+{
+ return _regulator_get_voltage(regulator->rcdev);
+}
+EXPORT_SYMBOL_GPL(regulator_get_voltage);
+
+int regulator_set_current(struct regulator *regulator, int uA)
+{
+ struct regulator_cdev *rcdev = regulator->rcdev;
+ int ret;
+
+ mutex_lock(&rcdev->mutex);
+
+ /* sanity check */
+ if (!rcdev->desc->ops->set_current) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* constraints check */
+ ret = regulator_check_current(rcdev, uA);
+ if (ret < 0)
+ goto out;
+
+ ret = rcdev->desc->ops->set_current(rcdev, uA);
+out:
+ mutex_unlock(&rcdev->mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_set_current);
+
+static int _regulator_get_current(struct regulator_cdev *rcdev)
+{
+ int ret;
+
+ mutex_lock(&rcdev->mutex);
+
+ /* sanity check */
+ if (!rcdev->desc->ops->get_current) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = rcdev->desc->ops->get_current(rcdev);
+out:
+ mutex_unlock(&rcdev->mutex);
+ return ret;
+}
+
+int regulator_get_current(struct regulator *regulator)
+{
+ return _regulator_get_current(regulator->rcdev);
+}
+EXPORT_SYMBOL_GPL(regulator_get_current);
+
+int regulator_set_mode(struct regulator *regulator, unsigned int mode)
+{
+ struct regulator_cdev *rcdev = regulator->rcdev;
+ int ret;
+
+ mutex_lock(&rcdev->mutex);
+
+ /* sanity check */
+ if (!rcdev->desc->ops->set_mode) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* constraints check */
+ ret = regulator_check_mode(rcdev, mode);
+ if (ret < 0)
+ goto out;
+
+ ret = rcdev->desc->ops->set_mode(rcdev, mode);
+out:
+ mutex_unlock(&rcdev->mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_set_mode);
+
+static unsigned int _regulator_get_mode(struct regulator_cdev *rcdev)
+{
+ int ret;
+
+ mutex_lock(&rcdev->mutex);
+
+ /* sanity check */
+ if (!rcdev->desc->ops->get_mode) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = rcdev->desc->ops->get_mode(rcdev);
+out:
+ mutex_unlock(&rcdev->mutex);
+ return ret;
+}
+
+unsigned int regulator_get_mode(struct regulator *regulator)
+{
+ return _regulator_get_mode(regulator->rcdev);
+}
+EXPORT_SYMBOL_GPL(regulator_get_mode);
+
+static unsigned int _regulator_get_optimum_mode(struct regulator_cdev *rcdev,
+ int input_uV, int output_uV, int load_uA)
+{
+ int ret;
+
+ mutex_lock(&rcdev->mutex);
+
+ /* sanity check */
+ if (!rcdev->desc->ops->get_optimum_mode) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = rcdev->desc->ops->get_optimum_mode(rcdev,
+ input_uV, output_uV, load_uA);
+out:
+ mutex_unlock(&rcdev->mutex);
+ return ret;
+}
+
+unsigned int regulator_get_optimum_mode(struct regulator *regulator,
+ int input_uV, int output_uV, int load_uA)
+{
+ return _regulator_get_optimum_mode(regulator->rcdev, input_uV,
+ output_uV, load_uA);
+}
+EXPORT_SYMBOL_GPL(regulator_get_optimum_mode);
+
+int regulator_register_client(struct regulator *regulator,
+ struct notifier_block *nb)
+{
+ return blocking_notifier_chain_register(&regulator->rcdev->notifier,
+ nb);
+}
+EXPORT_SYMBOL_GPL(regulator_register_client);
+
+int regulator_unregister_client(struct regulator *regulator,
+ struct notifier_block *nb)
+{
+ return blocking_notifier_chain_unregister(&regulator->rcdev->notifier,
+ nb);
+}
+EXPORT_SYMBOL_GPL(regulator_unregister_client);
+
+int regulator_notifier_call_chain(struct regulator_cdev *rcdev,
+ unsigned long event, void *data)
+{
+ return blocking_notifier_call_chain(&rcdev->notifier, event, data);
+}
+EXPORT_SYMBOL_GPL(regulator_notifier_call_chain);
+
+struct regulator_cdev *regulator_register(
+ struct regulator_desc *regulator_desc, void *reg_data)
+{
+ static atomic_t regulator_no = ATOMIC_INIT(0);
+ struct regulator_cdev *rcdev;
+ int ret;
+
+ if (regulator_desc == NULL)
+ return ERR_PTR(-EINVAL);
+
+ if (regulator_desc->name == NULL || regulator_desc->ops == NULL)
+ return ERR_PTR(-EINVAL);
+
+ if (!regulator_desc->type == REGULATOR_VOLTAGE &&
+ !regulator_desc->type == REGULATOR_CURRENT)
+ return ERR_PTR(-EINVAL);
+
+ rcdev = kzalloc(sizeof(struct regulator_cdev), GFP_KERNEL);
+ if (rcdev == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ mutex_lock(&list_mutex);
+
+ mutex_init(&rcdev->mutex);
+ rcdev->reg_data = reg_data;
+ rcdev->owner = regulator_desc->owner;
+ rcdev->desc = regulator_desc;
+ INIT_LIST_HEAD(&rcdev->consumer_list);
+ INIT_LIST_HEAD(&rcdev->list);
+ BLOCKING_INIT_NOTIFIER_HEAD(&rcdev->notifier);
+
+ rcdev->cdev.class = &regulator_class;
+ class_device_initialize(&rcdev->cdev);
+ snprintf(rcdev->cdev.class_id, sizeof(rcdev->cdev.class_id),
+ "regulator-%ld-%s",
+ (unsigned long) atomic_inc_return(&regulator_no) - 1,
+ regulator_desc->name);
+
+ ret = class_device_add(&rcdev->cdev);
+ if (ret == 0)
+ list_add(&rcdev->list, &regulator_cdevs);
+ else {
+ kfree(rcdev);
+ rcdev = ERR_PTR(ret);
+ }
+ mutex_unlock(&list_mutex);
+ return rcdev;
+}
+EXPORT_SYMBOL_GPL(regulator_register);
+
+void regulator_unregister(struct regulator_cdev *rcdev)
+{
+ if (rcdev == NULL)
+ return;
+
+ mutex_lock(&list_mutex);
+ list_del(&rcdev->list);
+ if (rcdev->parent)
+ sysfs_remove_link(&rcdev->cdev.kobj, "source");
+ class_device_unregister(&rcdev->cdev);
+ kfree(rcdev);
+ mutex_unlock(&list_mutex);
+}
+EXPORT_SYMBOL_GPL(regulator_unregister);
+
+int regulator_set_platform_source(const char *regulator_source,
+ const char *regulator_parent)
+{
+ struct regulator_cdev *source_rcdev, *parent_rcdev;
+ int err;
+
+ if (regulator_source == NULL || regulator_parent == NULL)
+ return -EINVAL;
+
+ mutex_lock(&list_mutex);
+
+ list_for_each_entry(source_rcdev, &regulator_cdevs, list) {
+ if (!strcmp(source_rcdev->desc->name, regulator_source))
+ goto found_source;
+ }
+ mutex_unlock(&list_mutex);
+ return -ENODEV;
+
+found_source:
+ list_for_each_entry(parent_rcdev, &regulator_cdevs, list) {
+ if (!strcmp(parent_rcdev->desc->name, regulator_parent))
+ goto found_parent;
+ }
+ mutex_unlock(&list_mutex);
+ return -ENODEV;
+
+found_parent:
+ source_rcdev->parent = parent_rcdev;
+ err = sysfs_create_link(&source_rcdev->cdev.kobj,
+ &parent_rcdev->cdev.kobj, "source");
+ if (err)
+ printk(KERN_WARNING
+ "%s: could not add device link %s err %d\n",
+ __func__, parent_rcdev->cdev.kobj.name, err);
+ mutex_unlock(&list_mutex);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(regulator_set_platform_source);
+
+const char *regulator_get_platform_source(const char *regulator_name)
+{
+ struct regulator_cdev *rcdev;
+
+ if (regulator_name == NULL)
+ return NULL;
+
+ mutex_lock(&list_mutex);
+ list_for_each_entry(rcdev, &regulator_cdevs, list) {
+ if (!strcmp(rcdev->desc->name, regulator_name))
+ goto found;
+ }
+ mutex_unlock(&list_mutex);
+ return NULL;
+
+found:
+ mutex_unlock(&list_mutex);
+ if (rcdev->parent)
+ return rcdev->parent->desc->name;
+ else
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(regulator_get_platform_source);
+
+int regulator_set_platform_constraints(const char *regulator_name,
+ struct regulation_constraints *constraints)
+{
+ struct regulator_cdev *rcdev;
+
+ if (regulator_name == NULL)
+ return -EINVAL;
+
+ mutex_lock(&list_mutex);
+ list_for_each_entry(rcdev, &regulator_cdevs, list) {
+ if (!strcmp(regulator_name, rcdev->desc->name)) {
+ mutex_lock(&rcdev->mutex);
+ rcdev->constraints = constraints;
+ print_constraints(rcdev);
+ mutex_unlock(&rcdev->mutex);
+ mutex_unlock(&list_mutex);
+ return 0;
+ }
+ }
+ mutex_unlock(&list_mutex);
+ return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(regulator_set_platform_constraints);
+
+void regulator_drms_notify_load(struct regulator *regulator, int uA)
+{
+ struct regulator_cdev *rcdev = regulator->rcdev;
+
+ mutex_lock(&rcdev->mutex);
+ regulator->uA_load = uA;
+ regulator_load_change (rcdev);
+ mutex_unlock(&rcdev->mutex);
+}
+EXPORT_SYMBOL_GPL(regulator_drms_notify_load);
+
+void *regulator_get_drvdata(struct regulator *regulator)
+{
+ return regulator->rcdev->reg_data;
+}
+EXPORT_SYMBOL_GPL(regulator_get_drvdata);
+
+void regulator_set_drvdata(struct regulator *regulator, void *data)
+{
+ regulator->rcdev->reg_data = data;
+}
+EXPORT_SYMBOL_GPL(regulator_set_drvdata);
+
+int rcdev_get_id (struct regulator_cdev *rcdev)
+{
+ return rcdev->desc->id;
+}
+EXPORT_SYMBOL_GPL(rcdev_get_id);
+
+void *rcdev_get_drvdata (struct regulator_cdev *rcdev)
+{
+ return rcdev->reg_data;
+}
+EXPORT_SYMBOL_GPL(rcdev_get_drvdata);
+
+static int __init regulator_init(void)
+{
+ printk(KERN_INFO "regulator: core version %s\n", REGULATOR_VERSION);
+ return class_register(&regulator_class);
+}
+
+/* init early to allow our consumers to complete system booting */
+core_initcall(regulator_init);
--
1.5.4.2

2008-02-23 08:14:46

by Andrew Morton

Subject: Re: [PATCH 4/6] regulator: regulator core.

On Wed, 20 Feb 2008 17:09:11 +0000 Liam Girdwood <[email protected]> wrote:

> This patch provides the regulator framework core. The core also provides a
> sysfs interface for userspace information.
>
> ...
>
> +
> +/* We need to undef the current macro (from include/asm/current.h) otherwise
> + * our "current" sysfs entry becomes "(get_current())".
> + */
> +#undef current

err, no ;) Please rename your stuff.

> +static DEFINE_MUTEX(list_mutex);
> +static LIST_HEAD(regulator_cdevs);
> +
> +/**
> + * struct regulator_cdev
> + *
> + * Voltage / Current regulator class device. One for each regulator.
> + */
> +struct regulator_cdev {
> + struct regulator_desc *desc;
> + int use_count;
> +
> + struct list_head list;
> + struct list_head consumer_list;
> + struct blocking_notifier_head notifier;
> + struct mutex mutex;
> + struct module *owner;
> + struct class_device cdev;
> + struct regulation_constraints *constraints;
> + struct regulator_cdev *parent; /* for tree */
> +
> + void *reg_data; /* regulator_cdev data */
> + void *vendor; /* regulator_cdev vendor extensions */
> +};
> +#define to_rcdev(cd) \
> + container_of(cd, struct regulator_cdev, cdev)

This could be a C function?

> +/*
> + * struct regulator
> + *
> + * One for each consumer device.
> + */
> +struct regulator {
> + struct device *dev;
> + struct list_head list;
> + int uA_load;
> + int uV_required;
> + int enabled;
> + struct device_attribute dev_attr;
> + struct regulator_cdev *rcdev;
> +};
> +
> +static int _regulator_is_enabled(struct regulator_cdev *rcdev);
> +static int _regulator_disable(struct regulator_cdev *rcdev);
> +static int _regulator_get_voltage(struct regulator_cdev *rcdev);
> +static int _regulator_get_current(struct regulator_cdev *rcdev);
> +static unsigned int _regulator_get_mode(struct regulator_cdev *rcdev);
> +
> +static struct regulator *get_regulator_load(struct device *dev)
> +{
> + struct regulator *regulator = NULL;
> + struct regulator_cdev *rcdev;
> +
> + list_for_each_entry(rcdev, &regulator_cdevs, list) {
> + list_for_each_entry(regulator, &rcdev->consumer_list, list) {
> + if (regulator->dev == dev)
> + return regulator;
> + }
> + }
> + return NULL;
> +}

afacit list_mutex is not held here.

> +static int regulator_check_voltage(struct regulator_cdev *rcdev, int uV)
> +{
> + if (!rcdev->constraints) {
> + printk(KERN_ERR "%s: no constraints for %s\n", __func__,
> + rcdev->desc->name);
> + return -ENODEV;
> + }
> + if (!rcdev->constraints->valid_ops_mask & REGULATOR_CHANGE_VOLTAGE) {
> + printk(KERN_ERR "%s: operation not allowed for %s\n",
> + __func__, rcdev->desc->name);
> + return -EPERM;
> + }
> + if (uV > rcdev->constraints->max_uV ||
> + uV < rcdev->constraints->min_uV) {
> + printk(KERN_ERR "%s: invalid voltage %duV for %s\n",
> + __func__, uV, rcdev->desc->name);
> + return -EINVAL;
> + }
> + return 0;
> +}
> +
> +static int regulator_check_current(struct regulator_cdev *rcdev, int uA)
> +{
> + if (!rcdev->constraints) {
> + printk(KERN_ERR "%s: no constraints for %s\n", __func__,
> + rcdev->desc->name);
> + return -ENODEV;
> + }
> + if (!rcdev->constraints->valid_ops_mask & REGULATOR_CHANGE_CURRENT) {

Spot the bug.

> + printk(KERN_ERR "%s: operation not allowed for %s\n",
> + __func__, rcdev->desc->name);
> + return -EPERM;
> + }
> + if (uA > rcdev->constraints->max_uA ||
> + uA < rcdev->constraints->min_uA) {
> + printk(KERN_ERR "%s: invalid current %duA for %s\n",
> + __func__, uA, rcdev->desc->name);
> + return -EINVAL;
> + }
> + return 0;
> +}
> +
> +static int regulator_check_mode(struct regulator_cdev *rcdev, int mode)
> +{
> + if (!rcdev->constraints) {
> + printk(KERN_ERR "%s: no constraints for %s\n", __func__,
> + rcdev->desc->name);
> + return -ENODEV;
> + }
> + if (!rcdev->constraints->valid_ops_mask & REGULATOR_CHANGE_MODE) {

Here too.

> + printk(KERN_ERR "%s: operation not allowed for %s\n",
> + __func__, rcdev->desc->name);
> + return -EPERM;
> + }
> + if (!rcdev->constraints->valid_modes_mask & mode) {

And again.

> + printk(KERN_ERR "%s: invalid mode %x for %s\n",
> + __func__, mode, rcdev->desc->name);
> + return -EINVAL;
> + }
> + return 0;
> +}
> +
> +static int regulator_check_drms(struct regulator_cdev *rcdev)
> +{
> + if (!rcdev->constraints) {
> + printk(KERN_ERR "%s: no constraints for %s\n", __func__,
> + rcdev->desc->name);
> + return -ENODEV;
> + }
> + if (!rcdev->constraints->valid_ops_mask & REGULATOR_CHANGE_DRMS) {

And again.

> + printk(KERN_ERR "%s: operation not allowed for %s\n",
> + __func__, rcdev->desc->name);
> + return -EPERM;
> + }
> + return 0;
> +}
> +
>
> ...
>
> +static ssize_t regulator_constraint_uA_show(struct class_device *cdev,
> + char *buf)
> +{
> + struct regulator_cdev *rcdev = to_rcdev(cdev);
> +
> + if (!rcdev->constraints)
> + return sprintf(buf, "constraints not defined\n");
> +
> + return sprintf (buf, "%d %d\n", rcdev->constraints->min_uA,
> + rcdev->constraints->max_uA);
> +}

Did we just break the one-value-per-sysfs-file rule?

This is one of the reasons why we like to see the full proposed ABI in the
changelog or in the added documentation.

> +static ssize_t regulator_constraint_uV_show(struct class_device *cdev,
> + char *buf)
> +{
> + struct regulator_cdev *rcdev = to_rcdev(cdev);
> +
> + if (!rcdev->constraints)
> + return sprintf(buf, "constraints not defined\n");
> +
> + return sprintf (buf, "%d %d\n", rcdev->constraints->min_uV,
> + rcdev->constraints->max_uV);
> +}

Ditto.

> +static ssize_t regulator_constraint_modes_show(struct class_device *cdev,
> + char *buf)
> +{
> + struct regulator_cdev *rcdev = to_rcdev(cdev);
> + int count = 0;
> +
> + if (!rcdev->constraints)
> + return sprintf(buf, "constraints not defined\n");
> +
> + if (rcdev->constraints->valid_modes_mask & REGULATOR_MODE_FAST)
> + count = sprintf (buf, "fast ");
> + if (rcdev->constraints->valid_modes_mask & REGULATOR_MODE_NORMAL)
> + count += sprintf (buf + count, "normal ");
> + if (rcdev->constraints->valid_modes_mask & REGULATOR_MODE_IDLE)
> + count += sprintf (buf + count, "idle ");
> + if (rcdev->constraints->valid_modes_mask & REGULATOR_MODE_STANDBY)
> + count += sprintf (buf + count, "standby");
> + count += sprintf(buf + count, "\n");
> + return count;
> +}

etc.

> +static ssize_t regulator_total_dev_load(struct class_device *cdev, char *buf)
> +{
> + struct regulator_cdev *rcdev = to_rcdev(cdev);
> + struct regulator *regulator;
> + int uA = 0;
> +
> + list_for_each_entry(regulator, &rcdev->consumer_list, list)
> + uA =+ regulator->uA_load;
> + return sprintf(buf, "%d\n", uA);
> +}

locking for that list?

> +static void regulator_dev_release(struct class_device *class_dev) {}

No, an empty ->release is a sign that something is wrong. Please ask Greg
KH for details - I always forget..

> +struct class regulator_class = {
> + .name = "regulator",
> + .release = regulator_dev_release,
> + .class_dev_attrs = regulator_dev_attrs,
> +};
> +
> +/* find the lowest stable voltage that all enabled clients can operate at */
> +static int get_lowest_stable_voltage(struct regulator_cdev *rcdev)
> +{
> + struct regulator *regulator;
> + int highest_uV = 0;
> +
> + list_for_each_entry(regulator, &rcdev->consumer_list, list) {
> + if (regulator->enabled && regulator->uV_required > highest_uV)
> + highest_uV = regulator->uV_required;
> + }
> + return highest_uV;
> +}

list locking?

> +/* set the regulator voltage to the lowest possible value that can safely
> + * support all the client devices */
> +static int regulator_set_stable_voltage(struct regulator_cdev *rcdev)
> +{
> + int ret = 0, uV;
> +
> + if (rcdev->desc->type == REGULATOR_VOLTAGE) {
> + uV = get_lowest_stable_voltage(rcdev);
> + if (uV && rcdev->desc->ops->set_voltage)
> + ret = rcdev->desc->ops->set_voltage(rcdev, uV);
> + }
> + return ret;
> +}
> +
> +static void regulator_load_change (struct regulator_cdev *rcdev)

checkpatch has a whale of a time with this diff.

> +{
> + struct regulator *sibling;
> + int current_uA = 0, output_uV, input_uV, err;
> + unsigned int mode;
> +
> + err = regulator_check_drms(rcdev);
> + if (err < 0 || !rcdev->desc->ops->get_optimum_mode ||
> + !rcdev->desc->ops->get_voltage || !rcdev->desc->ops->set_mode);
> + return;
> +
> + /* get output voltage */
> + output_uV = rcdev->desc->ops->get_voltage(rcdev);
> +
> + /* get input voltage */
> + if (rcdev->parent && rcdev->parent->desc->ops->get_voltage)
> + input_uV =
> + rcdev->parent->desc->ops->get_voltage(rcdev->parent);
> + else
> + input_uV = rcdev->constraints->input_uV;
> +
> + /* calc total requested load */
> + list_for_each_entry(sibling, &rcdev->consumer_list, list)
> + current_uA += sibling->uA_load;

locking?

> + /* now get the optimum mode for our new total regulator load */
> + mode = rcdev->desc->ops->get_optimum_mode(rcdev, input_uV,
> + output_uV, current_uA);
> +
> + /* check the new mode is allowed */
> + err = regulator_check_mode(rcdev, mode);
> + if (err == 0)
> + rcdev->desc->ops->set_mode(rcdev, mode);
> +}
> +
> +static void print_constraints(struct regulator_cdev *rcdev)
> +{
> + struct regulation_constraints *constraints = rcdev->constraints;
> + char buf[80];
> + int count;
> +
> + if (rcdev->desc->type == REGULATOR_VOLTAGE) {
> + if (constraints->min_uV == constraints->max_uV)
> + count = sprintf(buf, "%d mV ",
> + uV_to_mV(constraints->min_uV));
> + else
> + count = sprintf(buf, "%d <--> %d mV ",
> + uV_to_mV(constraints->min_uV),
> + uV_to_mV(constraints->max_uV));
> + } else {
> + if (constraints->min_uA == constraints->max_uA)
> + count = sprintf(buf, "%d mA ",
> + uA_to_mA(constraints->min_uA));
> + else
> + count = sprintf(buf, "%d <--> %d mA ",
> + uA_to_mA(constraints->min_uA),
> + uA_to_mA(constraints->max_uA));
> + }
> + if (constraints->valid_modes_mask & REGULATOR_MODE_FAST)
> + count += sprintf (buf + count, "fast ");
> + if (constraints->valid_modes_mask & REGULATOR_MODE_NORMAL)
> + count += sprintf (buf + count, "normal ");
> + if (constraints->valid_modes_mask & REGULATOR_MODE_IDLE)
> + count += sprintf (buf + count, "idle ");
> + if (constraints->valid_modes_mask & REGULATOR_MODE_STANDBY)
> + count += sprintf (buf + count, "standby");
> +
> + printk(KERN_INFO "regulator: %s: %s\n", rcdev->desc->name, buf);
> +}

one-value-per-file?

> +static struct regulator *create_regulator(struct regulator_cdev *rcdev,
> + struct device *dev)
> +{
> + struct regulator *regulator;
> + char buf[32];
> + int err;
> +
> + regulator = kzalloc(sizeof(*regulator), GFP_KERNEL);
> + if (regulator == NULL)
> + return NULL;
> +
> + regulator->rcdev = rcdev;
> + sprintf(buf, "current_requested-%s", regulator->rcdev->desc->name);

How are we avoiding buffer overruns here? I'd suggest the use of
scnprintf() and checking the return value, fail the whole thing if it got
truncated.

> + list_add(&regulator->list, &rcdev->consumer_list);

locking?

> + if (dev == NULL)
> + goto out;

This is odd-looking. If dev==NULL we "succeed" but don't fill things in.
What's happening here?

> + regulator->dev = dev;
> + regulator->dev_attr.attr.name = kstrdup(buf, GFP_KERNEL);
> + if (regulator->dev_attr.attr.name == NULL)
> + goto err_out;
> + regulator->dev_attr.attr.owner = THIS_MODULE;
> + regulator->dev_attr.attr.mode = 0444;
> + regulator->dev_attr.show = dev_load_show;
> + err = device_create_file(dev, &regulator->dev_attr);
> + if (err < 0) {
> + printk(KERN_WARNING "%s: could not add regulator_cdev load"
> + " sysfs\n", __func__);
> + goto err_out;
> + }
> + err = sysfs_create_link(&rcdev->cdev.kobj, &dev->kobj,
> + dev->kobj.name);
> + if (err) {
> + printk(KERN_WARNING
> + "%s: could not add device link %s err %d\n",
> + __func__, dev->kobj.name, err);
> + goto err_out;

Missing device_remove_file()?

> + }
> +out:
> + return regulator;
> +err_out:
> + kfree(regulator->dev_attr.attr.name);
> + list_del(&regulator->list);
> + kfree(regulator);
> + return NULL;
> +}
>
> ...
>
> +void regulator_put(struct regulator *regulator)
> +{
> + struct regulator_cdev *rcdev;
> +
> + if (regulator == NULL || IS_ERR(regulator))
> + return;
> +
> + rcdev = regulator->rcdev;
> +
> + /* remove any sysfs entries */
> + if (regulator->dev) {
> + sysfs_remove_link(&rcdev->cdev.kobj,
> + regulator->dev->kobj.name);
> + device_remove_file(regulator->dev, &regulator->dev_attr);
> + }
> + list_del(&regulator->list);

locking?

> + kfree(regulator->dev_attr.attr.name);
> + kfree(regulator);
> +
> + module_put(rcdev->owner);
> + mutex_unlock(&list_mutex);
> +}
> +EXPORT_SYMBOL_GPL(regulator_put);
> +
> +static int _regulator_enable(struct regulator_cdev *rcdev)
> +{
> + int ret = 0;
> +
> + /* if the regulator is currently disabled make sure we check
> + * it's parent, mode and required voltage */
> + if (rcdev->use_count == 0) {
> + if (rcdev->parent) {
> + ret = _regulator_enable(rcdev->parent);
> + if (ret < 0) {
> + printk(KERN_ERR "%s: failed to enable %s\n",
> + __func__, rcdev->desc->name);
> + goto out;
> + }
> + }
> + if (rcdev->desc->ops->enable) {
> + ret = regulator_set_stable_voltage(rcdev);
> + if (ret < 0) {
> + printk(KERN_ERR "%s: invalid voltage for %s\n",
> + __func__, rcdev->desc->name);
> + goto out;
> + }
> + regulator_load_change(rcdev);
> + ret = rcdev->desc->ops->enable(rcdev);
> + if (ret < 0) {
> + printk(KERN_ERR "%s: failed to enable %s\n",
> + __func__, rcdev->desc->name);
> + goto out;
> + }
> + }
> + } else {
> + ret = regulator_set_stable_voltage(rcdev);
> + if (ret < 0) {
> + printk(KERN_ERR "%s: invalid voltage for %s\n",
> + __func__, rcdev->desc->name);
> + goto out;
> + }
> + regulator_load_change(rcdev);
> + }
> + rcdev->use_count++;
> +out:
> + return ret;
> +}

Yeah, it's nicer to have the kerneldoc here, while yo're reading the code.

> +static int _regulator_disable(struct regulator_cdev *rcdev)
> +{
> + int ret = 0;
> +
> + /* make sure we are the last user before disabling this regulator */
> + if (rcdev->use_count == 1) {
> + if (rcdev->desc->ops->disable) {
> + ret = rcdev->desc->ops->disable(rcdev);
> + if (ret < 0) {
> + printk(KERN_ERR "%s: failed to disable %s\n",
> + __func__, rcdev->desc->name);
> + goto out;
> + }
> + }
> + /* decrease parent ref count and disable if required */
> + if (rcdev->parent)
> + _regulator_disable(rcdev->parent);
> + } else {
> + /* set to next best requested voltage and mode */
> + ret = regulator_set_stable_voltage(rcdev);
> + regulator_load_change(rcdev);
> + }
> + rcdev->use_count--;

locking for ->use_count?

> +out:
> + if (rcdev->use_count < 0) {
> + printk(KERN_ERR "%s: tried to disable too many times\n",
> + __func__);
> + rcdev->use_count = 0;
> + }
> + return ret;
> +}
> +

2008-02-23 09:52:51

by Russell King - ARM Linux

Subject: Re: [PATCH 4/6] regulator: regulator core.

On Sat, Feb 23, 2008 at 12:05:38AM -0800, Andrew Morton wrote:
> On Wed, 20 Feb 2008 17:09:11 +0000 Liam Girdwood <[email protected]> wrote:
>
> > This patch provides the regulator framework core. The core also provides a
> > sysfs interface for userspace information.
> >
> > ...
> >
> > +
> > +/* We need to undef the current macro (from include/asm/current.h) otherwise
> > + * our "current" sysfs entry becomes "(get_current())".
> > + */
> > +#undef current
>
> err, no ;) Please rename your stuff.

Renaming is not an option - "current" is an electronic term for which
there is no alternative. The real problem is this __ATTR macro crap:

+ __ATTR(current, 0444, regulator_uA_show, NULL),

#define __ATTR(_name,_mode,_show,_store) { \
.attr = {.name = __stringify(_name), .mode = _mode }, \
.show = _show, \
.store = _store, \
}

If __ATTR allowed the name to be passed as a string, instead of stupidly
stringifying it, then this wouldn't be needed. So I suggest that the
#undef stands _until_ we fix this stupid macro. Or we rename the
"current" macro to something that doesn't clash with accepted scientific
and engineering terminology.

2008-02-23 18:19:51

by Andrew Morton

Subject: Re: [PATCH 4/6] regulator: regulator core.

On Sat, 23 Feb 2008 09:52:17 +0000 Russell King - ARM Linux <[email protected]> wrote:

> On Sat, Feb 23, 2008 at 12:05:38AM -0800, Andrew Morton wrote:
> > On Wed, 20 Feb 2008 17:09:11 +0000 Liam Girdwood <[email protected]> wrote:
> >
> > > This patch provides the regulator framework core. The core also provides a
> > > sysfs interface for userspace information.
> > >
> > > ...
> > >
> > > +
> > > +/* We need to undef the current macro (from include/asm/current.h) otherwise
> > > + * our "current" sysfs entry becomes "(get_current())".
> > > + */
> > > +#undef current
> >
> > err, no ;) Please rename your stuff.
>
> Renaming is not an option - "current" is an electronic term for which
> there is no alternative.

amps, milliamps, amperage (the latter of which I've always disliked)

> The real problem is this __ATTR macro crap:
>
> + __ATTR(current, 0444, regulator_uA_show, NULL),

This interface would actually be *improved* if that sysfs file were named
"microamps" rather than "current". Because its units become
self-documenting. Similarly, s/voltage/millivolts/g

> #define __ATTR(_name,_mode,_show,_store) { \
> .attr = {.name = __stringify(_name), .mode = _mode }, \
> .show = _show, \
> .store = _store, \
> }
>
> If __ATTR allowed the name to be passed as a string, instead of stupidly
> stringifying it, then this wouldn't be needed. So I suggest that the
> #undef stands _until_ we fix this stupid macro.

yeah, macros suck.

> Or we rename the
> "current" macro to something that doesn't clash with accepted scientific
> and engineering terminology.

2008-02-23 19:36:46

by Ian molton

Subject: Re: [PATCH 4/6] regulator: regulator core.

On Sat, 2008-02-23 at 10:18 -0800, Andrew Morton wrote:
> > Renaming is not an option - "current" is an electronic term for
> which
> > there is no alternative.
>
> amps, milliamps,

Are units of current, not current itself.

> amperage (the latter of which I've always disliked)

Ugh.

2008-02-23 19:39:28

by Andrew Morton

Subject: Re: [PATCH 4/6] regulator: regulator core.

On Sat, 23 Feb 2008 19:26:36 +0000 ian <[email protected]> wrote:

> On Sat, 2008-02-23 at 10:18 -0800, Andrew Morton wrote:
> > > Renaming is not an option - "current" is an electronic term for
> > which
> > > there is no alternative.
> >
> > amps, milliamps,
>
> Are units of current, not current itself.

Right. And this is an argument *in favour* of naming the sysfs files
"amps" (actually microamps), not "current". It conveys more information.

2008-02-24 10:24:19

by Mark Brown

Subject: Re: [PATCH 4/6] regulator: regulator core.

On Sat, Feb 23, 2008 at 09:52:17AM +0000, Russell King - ARM Linux wrote:
> On Sat, Feb 23, 2008 at 12:05:38AM -0800, Andrew Morton wrote:

> > > +#undef current

> > err, no ;) Please rename your stuff.

> Renaming is not an option - "current" is an electronic term for which
> there is no alternative. The real problem is this __ATTR macro crap:

Indeed, and this is already being worked around by
drivers/power/power_supply_sysfs.c:

#define POWER_SUPPLY_ATTR(_name) \
{ \
.attr = { .name = #_name, .mode = 0444, .owner = THIS_MODULE }, \
.show = power_supply_show_property, \
.store = NULL, \
}

2008-02-24 11:19:21

by Russell King - ARM Linux

Subject: Re: [PATCH 4/6] regulator: regulator core.

On Sun, Feb 24, 2008 at 10:23:49AM +0000, Mark Brown wrote:
> On Sat, Feb 23, 2008 at 09:52:17AM +0000, Russell King - ARM Linux wrote:
> > On Sat, Feb 23, 2008 at 12:05:38AM -0800, Andrew Morton wrote:
>
> > > > +#undef current
>
> > > err, no ;) Please rename your stuff.
>
> > Renaming is not an option - "current" is an electronic term for which
> > there is no alternative. The real problem is this __ATTR macro crap:
>
> Indeed, and this is already being worked around by
> drivers/power/power_supply_sysfs.c:
>
> #define POWER_SUPPLY_ATTR(_name) \
> { \
> .attr = { .name = #_name, .mode = 0444, .owner = THIS_MODULE }, \

My argument is - why bother with stuff like this, why not just pass
"_name" as the string itself, rather than using the preprocessor to
turn symbols into strings thereby suffering these nasty interactions.

It's not like "_name" is used for anything other than generating a
string.

2008-02-24 18:27:42

by Pavel Machek

Subject: Re: [PATCH 4/6] regulator: regulator core.

On Sat 2008-02-23 19:26:36, ian wrote:
>
> On Sat, 2008-02-23 at 10:18 -0800, Andrew Morton wrote:
> > > Renaming is not an option - "current" is an electronic term for
> > which
> > > there is no alternative.
> >
> > amps, milliamps,
>
> Are units of current, not current itself.

And what? You can't measure anything but current in amps, so ambiguity
is not a problem.

--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

2008-02-24 22:47:40

by Ian molton

Subject: Re: [PATCH 4/6] regulator: regulator core.

On Sun, 2008-02-24 at 09:51 +0100, Pavel Machek wrote:

> And what? You can't measure anything but current in amps, so ambiguity
> is not a problem.

It not is the credible validation of the language English. Thanking you kindly.

-Ian