Some devices share a regulator supply, when the first one will request regulator disable, the second device will have it's supply cut off before graciously shutting down. Hence there will be timeouts and other failed operations. Implement a reference counter mechanism similar with what is done in Linux, to keep track of enable and disable requests, and only disable the regulator when the last of the consumers has requested shutdown.
Signed-off-by: Eugen Hristev eugen.hristev@collabora.com --- Changes in v2: - add info in header regarding the function
drivers/power/regulator/regulator_common.c | 22 ++++++++++++++++++++++ drivers/power/regulator/regulator_common.h | 13 +++++++++++++ 2 files changed, 35 insertions(+)
diff --git a/drivers/power/regulator/regulator_common.c b/drivers/power/regulator/regulator_common.c index 93d8196b381e..edda25336176 100644 --- a/drivers/power/regulator/regulator_common.c +++ b/drivers/power/regulator/regulator_common.c @@ -73,6 +73,23 @@ int regulator_common_set_enable(const struct udevice *dev, return 0; }
+ /* If previously enabled, increase count */ + if (enable && dev_pdata->enable_count > 0) { + dev_pdata->enable_count++; + return 0; + } + + if (!enable) { + if (dev_pdata->enable_count > 1) { + /* If enabled multiple times, decrease count */ + dev_pdata->enable_count--; + return 0; + } else if (!dev_pdata->enable_count) { + /* If already disabled, do nothing */ + return 0; + } + } + ret = dm_gpio_set_value(&dev_pdata->gpio, enable); if (ret) { pr_err("Can't set regulator : %s gpio to: %d\n", dev->name, @@ -87,5 +104,10 @@ int regulator_common_set_enable(const struct udevice *dev, if (!enable && dev_pdata->off_on_delay_us) udelay(dev_pdata->off_on_delay_us);
+ if (enable) + dev_pdata->enable_count++; + else + dev_pdata->enable_count--; + return 0; } diff --git a/drivers/power/regulator/regulator_common.h b/drivers/power/regulator/regulator_common.h index c10492f01675..7c701b69245d 100644 --- a/drivers/power/regulator/regulator_common.h +++ b/drivers/power/regulator/regulator_common.h @@ -13,6 +13,7 @@ struct regulator_common_plat { struct gpio_desc gpio; /* GPIO for regulator enable control */ unsigned int startup_delay_us; unsigned int off_on_delay_us; + unsigned int enable_count; };
int regulator_common_of_to_plat(struct udevice *dev, @@ -20,6 +21,18 @@ int regulator_common_of_to_plat(struct udevice *dev, char *enable_gpio_name); int regulator_common_get_enable(const struct udevice *dev, struct regulator_common_plat *dev_pdata); +/* + * Enable or Disable a regulator + * + * This is a reentrant function and subsequent calls that enable will + * increase an internal counter, and disable calls will decrease the counter. + * The actual resource will be enabled when the counter gets to 1 coming from 0, + * and disabled when it reaches 0 coming from 1. + * + * @dev: regulator device + * @dev_pdata: Platform data + * @enable: bool indicating whether to enable or disable the regulator + */ int regulator_common_set_enable(const struct udevice *dev, struct regulator_common_plat *dev_pdata, bool enable);