[U-Boot] [PATCH v3 3/7] rockchip: spi: rk_spi: select 198MHz input to the SPI module for the RK3399

[Simon Glass]

Hi Philipp,

On 17 April 2017 at 09:43, Philipp Tomsich <
philipp.tomsich at theobroma-systems.com> wrote:
> To provide more (runtime) configuration points for the SPI data rate
> at higher speeds (e.g. above 9MHz), we increase the module input rate
> to 198MHz (from 99MHz) for the RK3399.
>
> Signed-off-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>
>
> ---
>
> Changes in v3:
> - increase the module input clock from 99MHz to 198MHz for the RK3399
> (added in version 3)
>
> Changes in v2: None
>
> drivers/spi/rk_spi.c | 7 ++++---
> drivers/spi/rk_spi.h | 7 +++++++
> 2 files changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/spi/rk_spi.c b/drivers/spi/rk_spi.c
> index 3e44f17..63cceef 100644
> --- a/drivers/spi/rk_spi.c
> +++ b/drivers/spi/rk_spi.c
> @@ -208,10 +208,11 @@ static int rockchip_spi_probe(struct udevice *bus)
> priv->max_freq = plat->frequency;
>
> /*
> - * Use 99 MHz as our clock since it divides nicely into 594 MHz which
> - * is the assumed speed for CLK_GENERAL.
> + * Use 99 MHz (198MHz on the RK3399) as our clock since it
> + * divides nicely into 594 MHz which is the assumed speed for
> + * CLK_GENERAL.
> */
> - ret = clk_set_rate(&priv->clk, 99000000);
> + ret = clk_set_rate(&priv->clk, ROCKCHIP_SPI_MOD_CLK);
> if (ret < 0) {
> debug("%s: Failed to set clock: %d\n", __func__, ret);
> return ret;
> diff --git a/drivers/spi/rk_spi.h b/drivers/spi/rk_spi.h
> index f1ac812..ea262ed 100644
> --- a/drivers/spi/rk_spi.h
> +++ b/drivers/spi/rk_spi.h
> @@ -119,6 +119,13 @@ enum {
> };
>
> #define ROCKCHIP_SPI_TIMEOUT_MS 1000
> +
> +#if defined(CONFIG_ROCKCHIP_RK3399)
> +#define ROCKCHIP_SPI_MOD_CLK 198000000
> +#define ROCKCHIP_SPI_MAX_RATE 50000000
> +#else
> +#define ROCKCHIP_SPI_MOD_CLK 99000000
> #define ROCKCHIP_SPI_MAX_RATE 48000000
> +#endif

I'd like to avoid board- or soc-specific code in drivers. Is this setting
available in the device tree node? If not, perhaps use the root node
compatible string?

>
> #endif /* __RK_SPI_H */
> --
> 1.9.1
>

Regards,
Simon