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, ®ulator_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(®ulator->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, ®ulator->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(®ulator->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, ®ulator->dev_attr);
> + }
> + list_del(®ulator->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;
> +}
> +
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
