Adding support for supplied_from char * array. This is meant to store the
list of suppliers for a given supply, i.e. chargers for a battery. This
list can be populated through devicetree readily as well as passed
directly from the driver.
Signed-off-by: Rhyland Klein <rklein@xxxxxxxxxx>
---
v2:
- fixed multiline comment style
- fixed usage of ret to inside loop and directly return result of
power_supply_populate_supplied_from
v1:
- Changed from RFC v2 -> patch v1
- removed list logic, added logic to first verify all supplies are
present and defer probe until they are.
- after all devices are registered, populate the char ** supplied_from
array which simulates the case of dt not being used.
- added of_node element to struct power_supply
v2 (RFC):
- Simplified and renamed the logic to parse dt for the charger list.
- Tied the dt parsing directly to power_supply_register to make fewer
changes required for converting existing chargers/supplies.
drivers/power/power_supply_core.c | 140 +++++++++++++++++++++++++++++++++++++
include/linux/power_supply.h | 3 +
2 files changed, 143 insertions(+)
diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
index d843cc9..5e84321 100644
--- a/drivers/power/power_supply_core.c
+++ b/drivers/power/power_supply_core.c
@@ -88,6 +88,139 @@ void power_supply_changed(struct power_supply *psy)
}
EXPORT_SYMBOL_GPL(power_supply_changed);
+#ifdef CONFIG_OF
+#include <linux/of.h>
+
+static int __power_supply_populate_supplied_from(struct device *dev,
+ void *data)
+{
+ struct power_supply *psy = (struct power_supply *)data;
+ struct power_supply *epsy = dev_get_drvdata(dev);
+ struct device_node *np;
+ int i = 0;
+
+ do {
+ np = of_parse_phandle(psy->of_node, "power-supplies", i++);
+ if (!np)
+ continue;
+
+ if (np == epsy->of_node) {
+ dev_info(psy->dev, "%s: Found supply : %s\n",
+ psy->name, epsy->name);
+ psy->supplied_from[i-1] = (char *)epsy->name;
+ psy->num_supplies++;
+ break;
+ }
+ } while (np);
+
+ return 0;
+}
+
+int power_supply_populate_supplied_from(struct power_supply *psy)
+{
+ int error;
+
+ error = class_for_each_device(power_supply_class, NULL, psy,
+ __power_supply_populate_supplied_from);
+
+ dev_dbg(psy->dev, "%s %d\n", __func__, error);
+
+ return error;
+}
+
+static int __power_supply_find_supply_from_node(struct device *dev,
+ void *data)
+{
+ struct device_node *np = (struct device_node *)data;
+ struct power_supply *epsy = dev_get_drvdata(dev);
+
+ /* return error breaks out of class_for_each_device loop */
+ if (epsy->of_node == np)
+ return -EINVAL;
+
+ return 0;
+}
+
+int power_supply_find_supply_from_node(struct device_node *supply_node)
+{
+ int error;
+ struct device *dev;
+ struct class_dev_iter iter;
+
+ /*
+ * Use iterator to see if any other device is registered.
+ * This is required since class_for_each_device returns 0
+ * if there are no devices registered.
+ */
+ class_dev_iter_init(&iter, power_supply_class, NULL, NULL);
+ dev = class_dev_iter_next(&iter);
+
+ if (!dev)
+ return -EPROBE_DEFER;
+
+ /*
+ * We have to treat the return value as inverted, because if
+ * we return error on not found, then it won't continue looking.
+ * So we trick it by returning error on success to stop looking
+ * once the matching device is found.
+ */
+ error = class_for_each_device(power_supply_class, NULL, supply_node,
+ __power_supply_find_supply_from_node);
+
+ return error ? 0 : -EPROBE_DEFER;
+}
+
+int power_supply_check_supplies(struct power_supply *psy)
+{
+ struct device_node *np;
+ int cnt = 0;
+
+ /* If there is already a list honor it */
+ if (psy->supplied_from && psy->num_supplies > 0)
+ return 0;
+
+ /* No device node found, nothing to do */
+ if (!psy->of_node)
+ return 0;
+
+ do {
+ int ret;
+
+ np = of_parse_phandle(psy->of_node, "power-supplies", cnt++);
+ if (!np)
+ continue;
+
+ ret = power_supply_find_supply_from_node(np);
+ if (ret) {
+ dev_dbg(psy->dev, "Failed to find supply, defer!\n");
+ return -EPROBE_DEFER;
+ }
+ } while (np);
+
+ /* All supplies found, allocate char ** array for filling */
+ psy->supplied_from = devm_kzalloc(psy->dev, sizeof(psy->supplied_from),
+ GFP_KERNEL);
+ if (!psy->supplied_from) {
+ dev_err(psy->dev, "Couldn't allocate memory for supply list\n");
+ return -ENOMEM;
+ }
+
+ *psy->supplied_from = devm_kzalloc(psy->dev, sizeof(char *) * cnt,
+ GFP_KERNEL);
+ if (!*psy->supplied_from) {
+ dev_err(psy->dev, "Couldn't allocate memory for supply list\n");
+ return -ENOMEM;
+ }
+
+ return power_supply_populate_supplied_from(psy);
+}
+#else
+static inline int power_supply_check_supplies(struct power_supply *psy)
+{
+ return 0;
+}
+#endif
+
static int __power_supply_am_i_supplied(struct device *dev, void *data)
{
union power_supply_propval ret = {0,};
@@ -357,6 +490,12 @@ int power_supply_register(struct device *parent, struct power_supply *psy)
INIT_WORK(&psy->changed_work, power_supply_changed_work);
+ rc = power_supply_check_supplies(psy);
+ if (rc) {
+ dev_info(dev, "Not all required supplies found, defer probe\n");
+ goto check_supplies_failed;
+ }
+
rc = kobject_set_name(&dev->kobj, "%s", psy->name);
if (rc)
goto kobject_set_name_failed;
@@ -389,6 +528,7 @@ register_thermal_failed:
device_del(dev);
kobject_set_name_failed:
device_add_failed:
+check_supplies_failed:
put_device(dev);
success:
return rc;
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index c1cbd5e..3828cef 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -173,6 +173,9 @@ struct power_supply {
char **supplied_from;
size_t num_supplies;
+#ifdef CONFIG_OF
+ struct device_node *of_node;
+#endif
int (*get_property)(struct power_supply *psy,
enum power_supply_property psp,
--
1.7.9.5
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