On 16/09/2022 14:07, B. Niedermayr wrote:
> From: Benedikt Niedermayr <benedikt.niedermayr@xxxxxxxxxxx>
>
> The waitpin polarity can be configured via the WAITPIN<X>POLARITY bits
> in the GPMC_CONFIG register. This is currently not supported by the
> driver. This patch adds support for setting the required register bits
> with the "gpmc,wait-pin-polarity" dt-property.
>
> Signed-off-by: Benedikt Niedermayr <benedikt.niedermayr@xxxxxxxxxxx>
> ---
> drivers/memory/omap-gpmc.c | 27 +++++++++++++++++++++++++
> include/linux/platform_data/gpmc-omap.h | 6 ++++++
> 2 files changed, 33 insertions(+)
>
> diff --git a/drivers/memory/omap-gpmc.c b/drivers/memory/omap-gpmc.c
> index ea495e93766b..2853fc28bccc 100644
> --- a/drivers/memory/omap-gpmc.c
> +++ b/drivers/memory/omap-gpmc.c
> @@ -132,6 +132,7 @@
> #define GPMC_CONFIG_DEV_SIZE 0x00000002
> #define GPMC_CONFIG_DEV_TYPE 0x00000003
>
> +#define GPMC_CONFIG_WAITPINPOLARITY(pin) (BIT(pin) << 8)
> #define GPMC_CONFIG1_WRAPBURST_SUPP (1 << 31)
> #define GPMC_CONFIG1_READMULTIPLE_SUPP (1 << 30)
> #define GPMC_CONFIG1_READTYPE_ASYNC (0 << 29)
> @@ -1882,6 +1883,17 @@ int gpmc_cs_program_settings(int cs, struct gpmc_settings *p)
>
> gpmc_cs_write_reg(cs, GPMC_CS_CONFIG1, config1);
>
> + if (p->wait_pin_polarity != WAITPINPOLARITY_DEFAULT) {
> + config1 = gpmc_read_reg(GPMC_CONFIG);
> +
> + if (p->wait_pin_polarity == WAITPINPOLARITY_ACTIVE_LOW)
> + config1 &= ~GPMC_CONFIG_WAITPINPOLARITY(p->wait_pin);
> + else if (p->wait_pin_polarity == WAITPINPOLARITY_ACTIVE_HIGH)
> + config1 |= GPMC_CONFIG_WAITPINPOLARITY(p->wait_pin);
> +
> + gpmc_write_reg(GPMC_CONFIG, config1);
What happens if wait pin is shared and you have different polarities in
both of devices?
> + }
> +
> return 0;
> }
>
> @@ -1981,7 +1993,22 @@ void gpmc_read_settings_dt(struct device_node *np, struct gpmc_settings *p)
> __func__);
> }
>
> + p->wait_pin_polarity = WAITPINPOLARITY_DEFAULT;
> +
> if (!of_property_read_u32(np, "gpmc,wait-pin", &p->wait_pin)) {
> + if (!of_property_read_u32(np, "gpmc,wait-pin-polarity",
> + &p->wait_pin_polarity)) {
> + if (p->wait_pin_polarity != WAITPINPOLARITY_ACTIVE_HIGH &&
> + p->wait_pin_polarity != WAITPINPOLARITY_ACTIVE_LOW &&
> + p->wait_pin_polarity != WAITPINPOLARITY_DEFAULT) {
WAITPINPOLARITY_DEFAULT is not allowed in DT, so you can skip it.
> + pr_err("%s: Invalid wait-pin-polarity (pin: %d, pol: %d)\n",
dev_err, not pr_err
> + __func__, p->wait_pin, p->wait_pin_polarity);
Skip __func__
> + p->wait_pin_polarity = WAITPINPOLARITY_DEFAULT;
> + }
> + } else {
> + pr_err("%s: Failed to read gpmc,wait-pin-polarity\n", __func__);
Ditto.
> + }
> +
> p->wait_on_read = of_property_read_bool(np,
> "gpmc,wait-on-read");
> p->wait_on_write = of_property_read_bool(np,
> diff --git a/include/linux/platform_data/gpmc-omap.h b/include/linux/platform_data/gpmc-omap.h
> index c9cc4e32435d..c46c28069c31 100644
> --- a/include/linux/platform_data/gpmc-omap.h
> +++ b/include/linux/platform_data/gpmc-omap.h
> @@ -136,6 +136,11 @@ struct gpmc_device_timings {
> #define GPMC_MUX_AAD 1 /* Addr-Addr-Data multiplex */
> #define GPMC_MUX_AD 2 /* Addr-Data multiplex */
>
> +/* Wait pin polarity values */
> +#define WAITPINPOLARITY_DEFAULT -1
Missing prefix. This is a global header.
> +#define WAITPINPOLARITY_ACTIVE_LOW 0
> +#define WAITPINPOLARITY_ACTIVE_HIGH 1
> +
> struct gpmc_settings {
> bool burst_wrap; /* enables wrap bursting */
> bool burst_read; /* enables read page/burst mode */
> @@ -149,6 +154,7 @@ struct gpmc_settings {
> u32 device_width; /* device bus width (8 or 16 bit) */
> u32 mux_add_data; /* multiplex address & data */
> u32 wait_pin; /* wait-pin to be used */
> + u32 wait_pin_polarity; /* wait-pin polarity */
Skip the comment. You just copied the name of variable. Such comments
are useless.
We do not have KPIs in kernel to achieve some comment-ratio...
Best regards,
Krzysztof
