[PATCH v4 5/8] clk: add clock driver for SCMI agents

[Simon Glass]

On Wed, 9 Sep 2020 at 10:44, Etienne Carriere
<etienne.carriere at linaro.org> wrote:
>
> This change introduces a clock driver for SCMI agent devices. When
> SCMI agent and SCMI clock drivers are enabled, SCMI agent binds a
> clock device for each SCMI clock protocol devices enabled in the FDT.
>
> SCMI clock driver is embedded upon CONFIG_CLK_SCMI=y. If enabled,
> CONFIG_SCMI_AGENT is also enabled.
>
> SCMI Clock protocol is defined in the SCMI specification [1].
>
> Links: [1] https://developer.arm.com/architectures/system-architectures/software-standards/scmi
> Signed-off-by: Etienne Carriere <etienne.carriere at linaro.org>
> Cc: Lukasz Majewski <lukma at denx.de>
> Cc: Simon Glass <sjg at chromium.org>
> Cc: Peng Fan <peng.fan at nxp.com>
> Cc: Sudeep Holla <sudeep.holla at arm.com>
> ---
>
> Changes in v4:
> - Condition DM_GET_DRIVER(scmi_clock) to IS_ENABLED(CONFIG_CLK_SCMI)
>   to prevent a build error (linker) when CONFIG_CLK_SCMI is disabled.
>
> Changes in v3:
> - Rebased in the series without major conflict.
>
> Changes in v2:
> - CONFIG_CLK_SCMI depends on CONFIG_SCMI_FIRMWARE instead of
>   selecting CONFIG_SCMI_FIRMWARE.
> - Add inline comment description for structures and moves them to
>   source file top. Add/fixup some functions inline description comments.
> - Replace rc with ret as return value local variable label.
> - Fix scmi_clk_get_rate() return value to propagate error number.
> - Fix scmi_clk_set_rate() to request synchronous rate set operation:
>   drop flag SCMI_CLK_RATE_ASYNC_NORESP in the SCMI message payload.
> - Fix scmi_clk_set_rate() return value to return clock effective rate
>   on success.
> ---
>  drivers/clk/Kconfig                       |  8 ++
>  drivers/clk/Makefile                      |  1 +
>  drivers/clk/clk_scmi.c                    | 99 +++++++++++++++++++++++
>  drivers/firmware/scmi/scmi_agent-uclass.c | 14 +++-
>  include/scmi_protocols.h                  | 78 ++++++++++++++++++
>  5 files changed, 197 insertions(+), 3 deletions(-)
>  create mode 100644 drivers/clk/clk_scmi.c

Reviewed-by: Simon Glass <sjg at chromium.org>