| Message ID | 20250402202510.432888-7-hdegoede@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | platform/x86: int3472: Add handshake pin support | expand |
On Wed, Apr 2, 2025 at 11:25 PM Hans de Goede <hdegoede@redhat.com> wrote: > > Avoid the GPIO controlling the avdd regulator being driven low or high > for a very short time leading to spikes by adding an enable delay of 2 ms > and a minimum off to on delay of also 2 ms. How 2ms was derived? From experiments or is there any other hint (Intel published sources somewhere, etc)? The code looks good to me Reviewed-by: Andy Shevchenko <andy@kernel.org>
Hi, On 2-Apr-25 11:04 PM, Andy Shevchenko wrote: > On Wed, Apr 2, 2025 at 11:25 PM Hans de Goede <hdegoede@redhat.com> wrote: >> >> Avoid the GPIO controlling the avdd regulator being driven low or high >> for a very short time leading to spikes by adding an enable delay of 2 ms >> and a minimum off to on delay of also 2 ms. > > How 2ms was derived? From experiments or is there any other hint > (Intel published sources somewhere, etc)? 2 ms is the minimum time ovXXXX sensors need to have there reset line driven logical high to properly register the reset. So that seemed like a sane value to use here to me. > The code looks good to me > Reviewed-by: Andy Shevchenko <andy@kernel.org> Regards, Hans
On Thu, Apr 03, 2025 at 11:43:34AM +0200, Hans de Goede wrote: > On 2-Apr-25 11:04 PM, Andy Shevchenko wrote: > > On Wed, Apr 2, 2025 at 11:25 PM Hans de Goede <hdegoede@redhat.com> wrote: > >> > >> Avoid the GPIO controlling the avdd regulator being driven low or high > >> for a very short time leading to spikes by adding an enable delay of 2 ms > >> and a minimum off to on delay of also 2 ms. > > > > How 2ms was derived? From experiments or is there any other hint > > (Intel published sources somewhere, etc)? > > 2 ms is the minimum time ovXXXX sensors need to have there > reset line driven logical high to properly register the reset. > > So that seemed like a sane value to use here to me. Please, add it in the commit message / comment in next version.
diff --git a/drivers/platform/x86/intel/int3472/clk_and_regulator.c b/drivers/platform/x86/intel/int3472/clk_and_regulator.c index a08b953b597a..b4af17e8dcaf 100644 --- a/drivers/platform/x86/intel/int3472/clk_and_regulator.c +++ b/drivers/platform/x86/intel/int3472/clk_and_regulator.c @@ -187,6 +187,7 @@ void skl_int3472_unregister_clock(struct int3472_discrete_device *int3472) int skl_int3472_register_regulator(struct int3472_discrete_device *int3472, struct gpio_desc *gpio, + unsigned int enable_time, const char *supply_name, const char *second_sensor) { @@ -224,9 +225,9 @@ int skl_int3472_register_regulator(struct int3472_discrete_device *int3472, snprintf(regulator->regulator_name, sizeof(regulator->regulator_name), "%s-%s", acpi_dev_name(int3472->adev), supply_name); - int3472->regulator.rdesc = INT3472_REGULATOR( - int3472->regulator.regulator_name, - &int3472_gpio_regulator_ops); + regulator->rdesc = INT3472_REGULATOR(regulator->regulator_name, + &int3472_gpio_regulator_ops, + enable_time, GPIO_REGULATOR_OFF_ON_DELAY); cfg.dev = &int3472->adev->dev; cfg.init_data = &init_data; diff --git a/drivers/platform/x86/intel/int3472/common.h b/drivers/platform/x86/intel/int3472/common.h index b0638c29d847..271c23adb8ab 100644 --- a/drivers/platform/x86/intel/int3472/common.h +++ b/drivers/platform/x86/intel/int3472/common.h @@ -30,17 +30,22 @@ #define GPIO_REGULATOR_NAME_LENGTH (12 + GPIO_SUPPPLY_NAME_LENGTH) /* lower- + upper-case mapping */ #define GPIO_REGULATOR_SUPPLY_MAP_COUNT 2 +/* Ensure the GPIO is driven low/high for at least 2 ms before changing */ +#define GPIO_REGULATOR_ENABLE_TIME (2 * USEC_PER_MSEC) +#define GPIO_REGULATOR_OFF_ON_DELAY (2 * USEC_PER_MSEC) #define INT3472_LED_MAX_NAME_LEN 32 #define CIO2_SENSOR_SSDB_MCLKSPEED_OFFSET 86 -#define INT3472_REGULATOR(_name, _ops) \ +#define INT3472_REGULATOR(_name, _ops, _enable_time, _off_on_delay) \ (const struct regulator_desc) { \ .name = _name, \ .type = REGULATOR_VOLTAGE, \ .ops = _ops, \ .owner = THIS_MODULE, \ + .enable_time = _enable_time, \ + .off_on_delay = _off_on_delay, \ } #define to_int3472_clk(hw) \ @@ -132,6 +137,7 @@ void skl_int3472_unregister_clock(struct int3472_discrete_device *int3472); int skl_int3472_register_regulator(struct int3472_discrete_device *int3472, struct gpio_desc *gpio, + unsigned int enable_time, const char *supply_name, const char *second_sensor); void skl_int3472_unregister_regulator(struct int3472_discrete_device *int3472); diff --git a/drivers/platform/x86/intel/int3472/discrete.c b/drivers/platform/x86/intel/int3472/discrete.c index f6dae82739e5..a2db4fae0e6d 100644 --- a/drivers/platform/x86/intel/int3472/discrete.c +++ b/drivers/platform/x86/intel/int3472/discrete.c @@ -311,7 +311,9 @@ static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares, break; case INT3472_GPIO_TYPE_POWER_ENABLE: - ret = skl_int3472_register_regulator(int3472, gpio, con_id, + ret = skl_int3472_register_regulator(int3472, gpio, + GPIO_REGULATOR_ENABLE_TIME, + con_id, int3472->quirks.avdd_second_sensor); if (ret) err_msg = "Failed to map regulator to sensor\n";
Avoid the GPIO controlling the avdd regulator being driven low or high for a very short time leading to spikes by adding an enable delay of 2 ms and a minimum off to on delay of also 2 ms. Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- drivers/platform/x86/intel/int3472/clk_and_regulator.c | 7 ++++--- drivers/platform/x86/intel/int3472/common.h | 8 +++++++- drivers/platform/x86/intel/int3472/discrete.c | 4 +++- 3 files changed, 14 insertions(+), 5 deletions(-)