Re: [PATCH v6 5/6] reset: spacemit: define three more CCUs

Philipp Zabel
2025-05-08T09:11:51Z

On Di, 2025-05-06 at 16:06 -0500, Alex Elder wrote:
> Three more CCUs on the SpacemiT K1 SoC implement only resets, not clocks.
> Define these resets so they can be used.
>
> Signed-off-by: Alex Elder <elder@riscstar.com>
> ---
> drivers/clk/spacemit/ccu-k1.c | 24 ++++++++++++++++
> drivers/reset/spacemit/k1.c | 54 +++++++++++++++++++++++++++++++++++
> include/soc/spacemit/ccu_k1.h | 30 +++++++++++++++++++
> 3 files changed, 108 insertions(+)
>
> diff --git a/drivers/clk/spacemit/ccu-k1.c b/drivers/clk/spacemit/ccu-k1.c
> index 6b1845e899e5f..bddc83aff23cd 100644
> --- a/drivers/clk/spacemit/ccu-k1.c
> +++ b/drivers/clk/spacemit/ccu-k1.c
> @@ -939,6 +939,18 @@ static const struct spacemit_ccu_data k1_ccu_apmu_data = {
> .num = ARRAY_SIZE(k1_ccu_apmu_hws),
> };
>
> +static const struct spacemit_ccu_data k1_ccu_rcpu_data = {

The /* No clocks in the RCPU CCU */ comment belongs here, instead of in
the reset driver.

I wonder though, if these units have no clocks, why are they called
CCUs? It doesn't make much sense to me to add their compatibles to the
ccu-k1 driver only to load the reset aux driver. Why not just add a
platform driver next to the aux driver in reset-spacemit.ko for these
three?

> + .reset_name = "rcpu-reset",
> +};
> +
> +static const struct spacemit_ccu_data k1_ccu_rcpu2_data = {
> + .reset_name = "rcpu2-reset",
> +};
> +
> +static const struct spacemit_ccu_data k1_ccu_apbc2_data = {
> + .reset_name = "apbc2-reset",
> +};
> +
> static int spacemit_ccu_register(struct device *dev,
> struct regmap *regmap,
> struct regmap *lock_regmap,
> @@ -1106,6 +1118,18 @@ static const struct of_device_id of_k1_ccu_match[] = {
> .compatible = "spacemit,k1-syscon-apmu",
> .data = &k1_ccu_apmu_data,
> },
> + {
> + .compatible = "spacemit,k1-syscon-rcpu",
> + .data = &k1_ccu_rcpu_data,
> + },
> + {
> + .compatible = "spacemit,k1-syscon-rcpu2",
> + .data = &k1_ccu_rcpu2_data,
> + },
> + {
> + .compatible = "spacemit,k1-syscon-apbc2",
> + .data = &k1_ccu_apbc2_data,
> + },
> { }
> };
> MODULE_DEVICE_TABLE(of, of_k1_ccu_match);
> diff --git a/drivers/reset/spacemit/k1.c b/drivers/reset/spacemit/k1.c
> index 19a34f151b214..27434a1928261 100644
> --- a/drivers/reset/spacemit/k1.c
> +++ b/drivers/reset/spacemit/k1.c
> @@ -137,6 +137,57 @@ static const struct ccu_reset_controller_data k1_apmu_reset_data = {
> .count = ARRAY_SIZE(apmu_resets),
> };
>
> +static const struct ccu_reset_data rcpu_resets[] = {
> + [RESET_RCPU_SSP0] = RESET_DATA(RCPU_SSP0_CLK_RST, 0, BIT(0)),
> + [RESET_RCPU_I2C0] = RESET_DATA(RCPU_I2C0_CLK_RST, 0, BIT(0)),
> + [RESET_RCPU_UART1] = RESET_DATA(RCPU_UART1_CLK_RST, 0, BIT(0)),
> + [RESET_RCPU_IR] = RESET_DATA(RCPU_CAN_CLK_RST, 0, BIT(0)),
> + [RESET_RCPU_CAN] = RESET_DATA(RCPU_IR_CLK_RST, 0, BIT(0)),
> + [RESET_RCPU_UART0] = RESET_DATA(RCPU_UART0_CLK_RST, 0, BIT(0)),
> + [RESET_RCPU_HDMI_AUDIO] = RESET_DATA(AUDIO_HDMI_CLK_CTRL, 0, BIT(0)),
> +};
> +
> +static const struct ccu_reset_controller_data k1_rcpu_reset_data = {
> + /* No clocks in the RCPU CCU */

This information is not useful in the reset driver.

regards
Philipp