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    SubjectRe: [PATCH v2 3/8] pinctrl: msm: Add ability for drivers to supply a reserved GPIO list
    On Fri, 7 Jun 2019 at 10:29, Lee Jones <lee.jones@linaro.org> wrote:
    >
    > When booting MSM based platforms with Device Tree or some ACPI
    > implementations, it is possible to provide a list of reserved pins
    > via the 'gpio-reserved-ranges' and 'gpios' properties respectively.
    > However some ACPI tables are not populated with this information,
    > thus it has to come from a knowledgable device driver instead.
    >
    > Here we provide the MSM common driver with additional support to
    > parse this informtion and correctly populate the widely used
    > 'valid_mask'.
    >
    > Signed-off-by: Lee Jones <lee.jones@linaro.org>

    I'm not sure if this is the correct approach. Presumably, on ACPI
    systems, all the pinctl stuff is already set up by the firmware, and
    so we shouldn't touch *any* pins unless they have been requested
    explicitly. Is there any way we can support this in the current
    framework?

    > ---
    > drivers/pinctrl/qcom/pinctrl-msm.c | 18 ++++++++++++++++++
    > drivers/pinctrl/qcom/pinctrl-msm.h | 1 +
    > 2 files changed, 19 insertions(+)
    >
    > diff --git a/drivers/pinctrl/qcom/pinctrl-msm.c b/drivers/pinctrl/qcom/pinctrl-msm.c
    > index ee8119879c4c..3ac740b36508 100644
    > --- a/drivers/pinctrl/qcom/pinctrl-msm.c
    > +++ b/drivers/pinctrl/qcom/pinctrl-msm.c
    > @@ -607,8 +607,23 @@ static int msm_gpio_init_valid_mask(struct gpio_chip *chip)
    > int ret;
    > unsigned int len, i;
    > unsigned int max_gpios = pctrl->soc->ngpios;
    > + const int *reserved = pctrl->soc->reserved_gpios;
    > u16 *tmp;
    >
    > + /* Driver provided reserved list overrides DT and ACPI */
    > + if (reserved) {
    > + bitmap_fill(chip->valid_mask, max_gpios);
    > + for (i = 0; reserved[i] >= 0; i++) {
    > + if (i >= max_gpios || reserved[i] >= max_gpios) {
    > + dev_err(pctrl->dev, "invalid list of reserved GPIOs\n");
    > + return -EINVAL;
    > + }
    > + clear_bit(reserved[i], chip->valid_mask);
    > + }
    > +
    > + return 0;
    > + }
    > +
    > /* The number of GPIOs in the ACPI tables */
    > len = ret = device_property_read_u16_array(pctrl->dev, "gpios", NULL,
    > 0);
    > @@ -964,6 +979,9 @@ static void msm_gpio_irq_handler(struct irq_desc *desc)
    >
    > static bool msm_gpio_needs_valid_mask(struct msm_pinctrl *pctrl)
    > {
    > + if (pctrl->soc->reserved_gpios)
    > + return true;
    > +
    > return device_property_read_u16_array(pctrl->dev, "gpios", NULL, 0) > 0;
    > }
    >
    > diff --git a/drivers/pinctrl/qcom/pinctrl-msm.h b/drivers/pinctrl/qcom/pinctrl-msm.h
    > index c12048e54a6f..23b93ae92269 100644
    > --- a/drivers/pinctrl/qcom/pinctrl-msm.h
    > +++ b/drivers/pinctrl/qcom/pinctrl-msm.h
    > @@ -121,6 +121,7 @@ struct msm_pinctrl_soc_data {
    > bool pull_no_keeper;
    > const char *const *tiles;
    > unsigned int ntiles;
    > + const int *reserved_gpios;
    > };
    >
    > extern const struct dev_pm_ops msm_pinctrl_dev_pm_ops;
    > --
    > 2.17.1
    >
    >
    > _______________________________________________
    > linux-arm-kernel mailing list
    > linux-arm-kernel@lists.infradead.org
    > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

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