On Mon, Oct 10, 2011 at 09:49:38PM +0530, Rajendra Nayak wrote:
> Device nodes in DT can associate themselves with one or more
> regulators/supply by providing a list of phandles (to regulator nodes)
> and corresponding supply names.
>
> For Example:
> devicenode: node@0x0 {
> ...
> ...
> vmmc-supply = <®ulator1>;
> vpll-supply = <®ulator1>;
s/regulator1/regulator2
> };
>
> The driver would then do a regulator_get(dev, "vmmc"); to get
> regulator1 and do a regulator_get(dev, "vpll"); to get
> regulator2.
>
> of_get_regulator() extracts the regulator node for a given
> device, based on the supply name.
>
> Use it to look up the regulator for a given consumer from device tree, during
> a regulator_get(). If not found fallback and lookup through
> the regulator_map_list instead.
>
> Also, since the regulator dt nodes can use the same binding to
> associate with a parent regulator/supply, allow the drivers to
> specify a supply_name, which can then be used to lookup dt
> to find the parent phandle.
>
> Signed-off-by: Rajendra Nayak <rnayak@xxxxxx>
> ---
> drivers/regulator/core.c | 91 +++++++++++++++++++++++++++++++------
> include/linux/regulator/driver.h | 2 +
> 2 files changed, 78 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
> index d8e6a42..9a5ebbe 100644
> --- a/drivers/regulator/core.c
> +++ b/drivers/regulator/core.c
> @@ -25,9 +25,11 @@
> #include <linux/mutex.h>
> #include <linux/suspend.h>
> #include <linux/delay.h>
> +#include <linux/of.h>
> #include <linux/regulator/consumer.h>
> #include <linux/regulator/driver.h>
> #include <linux/regulator/machine.h>
> +#include <linux/regulator/of_regulator.h>
>
> #define CREATE_TRACE_POINTS
> #include <trace/events/regulator.h>
> @@ -131,6 +133,33 @@ static struct regulator *get_device_regulator(struct device *dev)
> return NULL;
> }
>
> +/**
> + * of_get_regulator - get a regulator device node based on supply name
> + * @dev: Device pointer for the consumer (of regulator) device
> + * @supply: regulator supply name
> + *
> + * Extract the regulator device node corresponding to the supply name.
> + * retruns the device node corresponding to the regulator if found, else
> + * returns NULL.
> + */
> +struct device_node *of_get_regulator(struct device *dev, const char *supply)
> +{
> + struct device_node *regnode = NULL;
> + char prop_name[32]; /* 32 is max size of property name */
> +
> + dev_dbg(dev, "Looking up %s-supply from device tree\n", supply);
> +
> + snprintf(prop_name, 32, "%s-supply", supply);
> + regnode = of_parse_phandle(dev->of_node, prop_name, 0);
> +
> + if (!regnode) {
> + pr_warn("%s: %s property in node %s references invalid phandle",
> + __func__, prop_name, dev->of_node->full_name);
> + return NULL;
> + }
> + return regnode;
> +}
> +
> /* Platform voltage constraint check */
> static int regulator_check_voltage(struct regulator_dev *rdev,
> int *min_uV, int *max_uV)
> @@ -1155,6 +1184,7 @@ static struct regulator *_regulator_get(struct device *dev, const char *id,
> struct regulator_map *map;
> struct regulator *regulator = ERR_PTR(-ENODEV);
> const char *devname = NULL;
> + struct device_node *node;
> int ret;
>
> if (id == NULL) {
> @@ -1167,6 +1197,23 @@ static struct regulator *_regulator_get(struct device *dev, const char *id,
>
> mutex_lock(®ulator_list_mutex);
>
> + /*
> + * Lookup happens in 3 ways
> + * 1. If a dev and dev->of_node exist, look for a
> + * regulator mapping in dt node.
> + * 2. Check if a match can be found in regulator_map_list
> + * if regulator info is still passed in non-dt way
> + * 3. if !dev, then just look for a matching regulator name.
> + * Useful for dt builds using regulator_get() without specifying
> + * a device.
> + */
> + if (dev && dev->of_node) {
> + node = of_get_regulator(dev, id);
> + if (node)
> + list_for_each_entry(rdev, ®ulator_list, list)
> + if (node == rdev->dev.parent->of_node)
If we move DT parsing procedure into regulator core, we will be able to
find the of_node for given regulator and attach it to rdev->dev when
regulator_register() gets called by regulator drivers. Then we will
have 'if (node == rdev->dev.of_node)' here which makes more sense to me.
Regards,
Shawn
> + goto found;
> + }
> list_for_each_entry(map, ®ulator_map_list, list) {
> /* If the mapping has a device set up it must match */
> if (map->dev_name &&
> @@ -1178,6 +1225,10 @@ static struct regulator *_regulator_get(struct device *dev, const char *id,
> goto found;
> }
> }
> + if (!dev)
> + list_for_each_entry(rdev, ®ulator_list, list)
> + if (strcmp(rdev_get_name(rdev), id))
> + goto found;
>
> if (board_wants_dummy_regulator) {
> rdev = dummy_regulator_rdev;
> @@ -2579,6 +2630,7 @@ struct regulator_dev *regulator_register(struct regulator_desc *regulator_desc,
> static atomic_t regulator_no = ATOMIC_INIT(0);
> struct regulator_dev *rdev;
> int ret, i;
> + const char *supply;
>
> if (regulator_desc == NULL)
> return ERR_PTR(-EINVAL);
> @@ -2653,25 +2705,34 @@ struct regulator_dev *regulator_register(struct regulator_desc *regulator_desc,
> if (ret < 0)
> goto scrub;
>
> - if (init_data->supply_regulator) {
> - struct regulator_dev *r;
> - int found = 0;
> + if (init_data->supply_regulator)
> + supply = init_data->supply_regulator;
> + else if (regulator_desc->supply_name);
> + supply = regulator_desc->supply_name;
>
> - list_for_each_entry(r, ®ulator_list, list) {
> - if (strcmp(rdev_get_name(r),
> - init_data->supply_regulator) == 0) {
> - found = 1;
> - break;
> - }
> + if (supply) {
> + struct regulator_dev *r;
> + struct device_node *node;
> +
> + /* first do a dt based lookup */
> + if (dev) {
> + node = of_get_regulator(dev, supply);
> + if (node)
> + list_for_each_entry(r, ®ulator_list, list)
> + if (node == r->dev.parent->of_node)
> + goto found;
> }
>
> - if (!found) {
> - dev_err(dev, "Failed to find supply %s\n",
> - init_data->supply_regulator);
> - ret = -ENODEV;
> - goto scrub;
> - }
> + /* next try doing it non-dt way */
> + list_for_each_entry(r, ®ulator_list, list)
> + if (strcmp(rdev_get_name(r), supply) == 0)
> + goto found;
>
> + dev_err(dev, "Failed to find supply %s\n", supply);
> + ret = -ENODEV;
> + goto scrub;
> +
> +found:
> ret = set_supply(rdev, r);
> if (ret < 0)
> goto scrub;
> diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
> index 1a80bc7..65ca5ff 100644
> --- a/include/linux/regulator/driver.h
> +++ b/include/linux/regulator/driver.h
> @@ -153,6 +153,7 @@ enum regulator_type {
> * this type.
> *
> * @name: Identifying name for the regulator.
> + * @supply_name: Identifying the regulator supply
> * @id: Numerical identifier for the regulator.
> * @n_voltages: Number of selectors available for ops.list_voltage().
> * @ops: Regulator operations table.
> @@ -162,6 +163,7 @@ enum regulator_type {
> */
> struct regulator_desc {
> const char *name;
> + const char *supply_name;
> int id;
> unsigned n_voltages;
> struct regulator_ops *ops;
> --
> 1.7.1
>
> _______________________________________________
> devicetree-discuss mailing list
> devicetree-discuss@xxxxxxxxxxxxxxxx
> https://lists.ozlabs.org/listinfo/devicetree-discuss
>
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