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pinctrl: qcom: spmi-gpio: make direction changes exclusive

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Neither direction callback clears the opposite buffer: .direction_output()
only packs PIN_CONFIG_LEVEL and .direction_input() only packs
PIN_CONFIG_INPUT_ENABLE.  As pmic_gpio_populate() seeds input_enabled and
output_enabled from MODE_CTL, a pad left in DIGITAL_INPUT[_OUTPUT] by the
bootloader ends up in DIGITAL_INPUT_OUTPUT whichever direction is
requested.  That leaves an input still driving the line, and makes
pmic_gpio_get_direction() report an output as an input, which breaks
consumers that read the direction back:

  reg-fixed-voltage regulator-wcn-core-vm-1p35: setup of GPIO (default) failed: -1
  reg-fixed-voltage regulator-wcn-core-vm-1p35: error -EPERM: can't get GPIO

Pack the opposite buffer's PIN_CONFIG_*_ENABLE along with the requested
direction, so MODE_CTL becomes DIGITAL_INPUT or DIGITAL_OUTPUT, never
both.  pmic_gpio_config_set() writes the registers once after walking all
configs, so this stays a single write.

An open-drain or open-source output is the exception: it only drives one
rail, so pmic_gpio_get() needs the input buffer to sample the line rather
than return the value last written.  Program the input buffer from
pad->buffer_type, which gpiolib has already updated via
PIN_CONFIG_DRIVE_OPEN_DRAIN, and key pmic_gpio_get_direction() off
output_enabled so such pads still read back as outputs.

Genuinely bidirectional pads can still be described that way through
pinconf; the gpiolib callbacks now mean what gpiolib says they mean.

Fixes: 2634475324 ("pinctrl: qcom: spmi-gpio: implement .get_direction()")
Assisted-by: LLM
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Shawn Guo <shengchao.guo@oss.qualcomm.com>
Link: https://patch.msgid.link/20260927010913.1212600-1-shengchao.guo@oss.qualcomm.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
This commit is contained in:
Shawn Guo 2026-09-27 09:09:13 +08:00 committed by Bartosz Golaszewski
parent 8157cd417d
commit 19fc424035
1 changed files with 29 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

37
drivers/pinctrl/qcom/pinctrl-spmi-gpio.c
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@ -734,29 +734,50 @@ static int pmic_gpio_get_direction(struct gpio_chip *chip, unsigned pin)
(!pad->input_enabled && !pad->output_enabled))
return -EINVAL;
/* Make sure the state is aligned on what pmic_gpio_get() returns */
return pad->input_enabled ? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT;
/*
* An open-drain or open-source pad keeps its input buffer enabled while
* driving, so the output buffer is what tells the direction.
*/
return pad->output_enabled ? GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
}
static int pmic_gpio_direction_input(struct gpio_chip *chip, unsigned pin)
{
struct pmic_gpio_state *state = gpiochip_get_data(chip);
unsigned long config;
unsigned long configs[2];
config = pinconf_to_config_packed(PIN_CONFIG_INPUT_ENABLE, 1);
configs[0] = pinconf_to_config_packed(PIN_CONFIG_OUTPUT_ENABLE, 0);
configs[1] = pinconf_to_config_packed(PIN_CONFIG_INPUT_ENABLE, 1);
return pmic_gpio_config_set(state->ctrl, pin, &config, 1);
return pmic_gpio_config_set(state->ctrl, pin, configs,
ARRAY_SIZE(configs));
}
static int pmic_gpio_direction_output(struct gpio_chip *chip,
unsigned pin, int val)
{
struct pmic_gpio_state *state = gpiochip_get_data(chip);
unsigned long config;
struct pmic_gpio_pad *pad = state->ctrl->desc->pins[pin].drv_data;
unsigned long configs[2];
config = pinconf_to_config_packed(PIN_CONFIG_LEVEL, val);
/*
* An open-drain or open-source pad only ever drives one rail, so the
* line can still be sampled while the pad is an output. Keep the input
* buffer enabled for those, so that pmic_gpio_get() reports what is on
* the wire rather than the value last written, and disable it for a
* CMOS pad, so that the pad ends up in DIGITAL_OUTPUT rather than
* DIGITAL_INPUT_OUTPUT. Program it either way, as the buffer may have
* been left in the opposite state by the bootloader or by an earlier
* direction change with a different buffer type. gpiolib applies
* PIN_CONFIG_DRIVE_OPEN_DRAIN before calling this, so buffer_type is
* already up to date here.
*/
configs[0] = pinconf_to_config_packed(PIN_CONFIG_INPUT_ENABLE,
pad->buffer_type != PMIC_GPIO_OUT_BUF_CMOS);
configs[1] = pinconf_to_config_packed(PIN_CONFIG_LEVEL, val);
return pmic_gpio_config_set(state->ctrl, pin, &config, 1);
return pmic_gpio_config_set(state->ctrl, pin, configs,
ARRAY_SIZE(configs));
}
static int pmic_gpio_get(struct gpio_chip *chip, unsigned pin)