Quoting Gwendal Grignou (2021-02-12 13:40:33)
> Use device_property_read_... to support both device tree and ACPI
> bindings.
> Given |semtech,combined-sensors| is a variable array, use
> device_property_count to get the length of the array first before
> reading it to avoid underflow errors.
>
> Add support for variable array per documentation
> ("iio/proximity/semtech,sx9310.yaml").
>
> Signed-off-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
> Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
It's attempting to fix a bug. Please add
Fixes: 5b19ca2c78a0 ("iio: sx9310: Set various settings from DT")
> diff --git a/drivers/iio/proximity/sx9310.c b/drivers/iio/proximity/sx9310.c
> index 6a04959df35e5..6440d12773c64 100644
> --- a/drivers/iio/proximity/sx9310.c
> +++ b/drivers/iio/proximity/sx9310.c
> @@ -1215,31 +1216,42 @@ static int sx9310_init_compensation(struct iio_dev *indio_dev)
> }
>
> static const struct sx9310_reg_default *
> -sx9310_get_default_reg(struct sx9310_data *data, int i,
> +sx9310_get_default_reg(struct device *dev, int i,
> struct sx9310_reg_default *reg_def)
> {
> - int ret;
> - const struct device_node *np = data->client->dev.of_node;
> + int ret, count;
> u32 combined[SX9310_NUM_CHANNELS] = { 4, 4, 4, 4 };
> unsigned long comb_mask = 0;
> const char *res;
> u32 start = 0, raw = 0, pos = 0;
>
> memcpy(reg_def, &sx9310_default_regs[i], sizeof(*reg_def));
> - if (!np)
> - return reg_def;
> -
> switch (reg_def->reg) {
> case SX9310_REG_PROX_CTRL2:
> - if (of_property_read_bool(np, "semtech,cs0-ground")) {
> + if (device_property_read_bool(dev, "semtech,cs0-ground")) {
> reg_def->def &= ~SX9310_REG_PROX_CTRL2_SHIELDEN_MASK;
> reg_def->def |= SX9310_REG_PROX_CTRL2_SHIELDEN_GROUND;
> }
>
> reg_def->def &= ~SX9310_REG_PROX_CTRL2_COMBMODE_MASK;
This should move after the parsing of the property, and only be done if
the semtech,combined-sensors property is present and valid.
> - of_property_read_u32_array(np, "semtech,combined-sensors",
> - combined, ARRAY_SIZE(combined));
> - for (i = 0; i < ARRAY_SIZE(combined); i++) {
> + count = device_property_count_u32(dev, "semtech,combined-sensors");
> + if (count > 0 && count <= ARRAY_SIZE(combined))
> + ret = device_property_read_u32_array(dev,
> + "semtech,combined-sensors", combined,
> + count);
> + else
> + ret = -EINVAL;
> + if (ret) {
> + /*
> + * Either the property does not exist in the DT, the
> + * number of entries is incorrect, or we could not read
> + * the array (invalid DT).
> + * In all cases, use the default from the diver.
> + */
> + count = ARRAY_SIZE(combined);
> + }
> +
> + for (i = 0; i < count; i++) {
> if (combined[i] <= SX9310_NUM_CHANNELS)
> comb_mask |= BIT(combined[i]);
