Hi,
On 10/7/23 04:12, Hao Yao wrote:
> Handshake pin is used for Lattice MIPI aggregator to enable the
> camera sensor. After pulled up, recommend to wail ~250ms to get
> everything ready.
If this is a pin on the "Lattice MIPI aggregator" and
not on the sensor itself then this really should be
modeled as such and should not be registered as a GPIO
consumed by the sensor since the actual sensor does not
have a handshake pin at all.
Also we really don't want to need to patch all involved
sensor drivers to toggle a handshake pin, especially since
the sensor itself does not physically have this pin.
Can you explain a bit more:
1. What the "Lattice MIPI aggregator" is
2. What its functions are, does this control reset + pwdn
GPIOs for the sensor? Voltages to the sensor? Clk
to the sensor ?
3. How the aggregator is connected to both the main
CPU/SoC as well as how it is connected to the sensor ?
Some example diagram would be really helpful here.
Then with this info in hand we can try to come up
with a way how to model this.
Assuming this controls the entire power-up sequence
for the sensor then I think it could be modelled
as a GPIO regulator. This also allows making the
regulator core take care of the necessary delay
between setting the GPIO and trying to talk to
the sensor.
Regards,
Hans
>
> Signed-off-by: Hao Yao <hao.yao@xxxxxxxxx>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---
> drivers/platform/x86/intel/int3472/common.h | 1 +
> drivers/platform/x86/intel/int3472/discrete.c | 5 +++++
> 2 files changed, 6 insertions(+)
>
> diff --git a/drivers/platform/x86/intel/int3472/common.h b/drivers/platform/x86/intel/int3472/common.h
> index 655ae3ec0593..3ad4c72afb45 100644
> --- a/drivers/platform/x86/intel/int3472/common.h
> +++ b/drivers/platform/x86/intel/int3472/common.h
> @@ -23,6 +23,7 @@
> #define INT3472_GPIO_TYPE_POWER_ENABLE 0x0b
> #define INT3472_GPIO_TYPE_CLK_ENABLE 0x0c
> #define INT3472_GPIO_TYPE_PRIVACY_LED 0x0d
> +#define INT3472_GPIO_TYPE_HANDSHAKE 0x12
>
> #define INT3472_PDEV_MAX_NAME_LEN 23
> #define INT3472_MAX_SENSOR_GPIOS 3
> diff --git a/drivers/platform/x86/intel/int3472/discrete.c b/drivers/platform/x86/intel/int3472/discrete.c
> index b644ce65c990..4753161b4080 100644
> --- a/drivers/platform/x86/intel/int3472/discrete.c
> +++ b/drivers/platform/x86/intel/int3472/discrete.c
> @@ -111,6 +111,10 @@ static void int3472_get_func_and_polarity(u8 type, const char **func, u32 *polar
> *func = "power-enable";
> *polarity = GPIO_ACTIVE_HIGH;
> break;
> + case INT3472_GPIO_TYPE_HANDSHAKE:
> + *func = "handshake";
> + *polarity = GPIO_ACTIVE_HIGH;
> + break;
> default:
> *func = "unknown";
> *polarity = GPIO_ACTIVE_HIGH;
> @@ -201,6 +205,7 @@ static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
> switch (type) {
> case INT3472_GPIO_TYPE_RESET:
> case INT3472_GPIO_TYPE_POWERDOWN:
> + case INT3472_GPIO_TYPE_HANDSHAKE:
> ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, func, polarity);
> if (ret)
> err_msg = "Failed to map GPIO pin to sensor\n";
