[RFC 4/7] pinctrl-scmi: add PIN_CONFIG_INPUT_VALUE

From: Dan Carpenter
Date: Mon May 05 2025 - 07:38:26 EST


In SCMI the value of the pin is just another configuration option. Add
this as an option in the pin_config_param enum and creating a mapping to
SCMI_PIN_INPUT_VALUE in pinctrl_scmi_map_pinconf_type()

Since this is an RFC patch, I'm going to comment that I think the SCMI
pinctrl driver misuses the PIN_CONFIG_OUTPUT enum. It should be for
enabling and disabling output on pins which can serve as both input and
output. Enabling it is supposed to write a 1 and disabling it is
supposed to write a 0 but we use that side effect to write 1s and 0s. I
did't change this because it would break userspace but I'd like to add a
PIN_CONFIG_OUTPUT_VALUE enum as well and use that in the GPIO driver.
But in this patchset I just use PIN_CONFIG_OUTPUT.

Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
drivers/pinctrl/pinctrl-scmi.c | 3 +++
include/linux/pinctrl/pinconf-generic.h | 3 +++
2 files changed, 6 insertions(+)

diff --git a/drivers/pinctrl/pinctrl-scmi.c b/drivers/pinctrl/pinctrl-scmi.c
index df4bbcd7d1d5..362a6d2c3c68 100644
--- a/drivers/pinctrl/pinctrl-scmi.c
+++ b/drivers/pinctrl/pinctrl-scmi.c
@@ -250,6 +250,9 @@ static int pinctrl_scmi_map_pinconf_type(enum pin_config_param param,
case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
*type = SCMI_PIN_INPUT_MODE;
break;
+ case PIN_CONFIG_INPUT_VALUE:
+ *type = SCMI_PIN_INPUT_VALUE;
+ break;
case PIN_CONFIG_MODE_LOW_POWER:
*type = SCMI_PIN_LOW_POWER_MODE;
break;
diff --git a/include/linux/pinctrl/pinconf-generic.h b/include/linux/pinctrl/pinconf-generic.h
index 1bcf071b860e..b37838171581 100644
--- a/include/linux/pinctrl/pinconf-generic.h
+++ b/include/linux/pinctrl/pinconf-generic.h
@@ -83,6 +83,8 @@ struct pinctrl_map;
* schmitt-trigger mode is disabled.
* @PIN_CONFIG_INPUT_SCHMITT_UV: this will configure an input pin to run in
* schmitt-trigger mode. The argument is in uV.
+ * @PIN_CONFIG_INPUT_VALUE: This is used in SCMI to read the value from the
+ * pin.
* @PIN_CONFIG_MODE_LOW_POWER: this will configure the pin for low power
* operation, if several modes of operation are supported these can be
* passed in the argument on a custom form, else just use argument 1
@@ -135,6 +137,7 @@ enum pin_config_param {
PIN_CONFIG_INPUT_SCHMITT,
PIN_CONFIG_INPUT_SCHMITT_ENABLE,
PIN_CONFIG_INPUT_SCHMITT_UV,
+ PIN_CONFIG_INPUT_VALUE,
PIN_CONFIG_MODE_LOW_POWER,
PIN_CONFIG_MODE_PWM,
PIN_CONFIG_OUTPUT,
--
2.47.2