[PATCH 3/4] clk: add clock driver for SCMI agents
Simon Glass
sjg at chromium.org
Sun Jul 26 16:54:17 CEST 2020
Hi Etienne,
On Fri, 17 Jul 2020 at 09:43, 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
That doesn't seem to work for me (404 error)
> Signed-off-by: Etienne Carriere <etienne.carriere at linaro.org>
> ---
>
> drivers/clk/Kconfig | 8 +++
> drivers/clk/Makefile | 1 +
> drivers/clk/clk_scmi.c | 152 ++++++++++++++++++++++++++++++++++++++++
> drivers/firmware/scmi.c | 3 +
> 4 files changed, 164 insertions(+)
> create mode 100644 drivers/clk/clk_scmi.c
>
> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> index 82cb1874e19..234d6035202 100644
> --- a/drivers/clk/Kconfig
> +++ b/drivers/clk/Kconfig
> @@ -152,6 +152,14 @@ config CLK_CDCE9XX
> Enable the clock synthesizer driver for CDCE913/925/937/949
> series of chips.
>
> +config CLK_SCMI
> + bool "Enable SCMI clock driver"
> + select SCMI_FIRMWARE
perhaps 'depends on' would be better?
> + help
> + Enable this option if you want to support clock devices exposed
> + by a SCMI agent based on SCMI clock protocol communication
> + with a SCMI server.
> +
> source "drivers/clk/analogbits/Kconfig"
> source "drivers/clk/at91/Kconfig"
> source "drivers/clk/exynos/Kconfig"
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index d9119545810..76bba77d1f0 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -31,6 +31,7 @@ obj-$(CONFIG_CLK_K210) += kendryte/
> obj-$(CONFIG_CLK_MPC83XX) += mpc83xx_clk.o
> obj-$(CONFIG_CLK_OWL) += owl/
> obj-$(CONFIG_CLK_RENESAS) += renesas/
> +obj-$(CONFIG_CLK_SCMI) += clk_scmi.o
> obj-$(CONFIG_CLK_SIFIVE) += sifive/
> obj-$(CONFIG_ARCH_SUNXI) += sunxi/
> obj-$(CONFIG_CLK_STM32F) += clk_stm32f.o
> diff --git a/drivers/clk/clk_scmi.c b/drivers/clk/clk_scmi.c
> new file mode 100644
> index 00000000000..efe64a6a38f
> --- /dev/null
> +++ b/drivers/clk/clk_scmi.c
> @@ -0,0 +1,152 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2019-2020 Linaro Limited
> + */
> +#include <common.h>
> +#include <clk-uclass.h>
> +#include <dm.h>
> +#include <scmi.h>
> +#include <asm/types.h>
> +
> +enum scmi_clock_message_id {
> + SCMI_CLOCK_RATE_SET = 0x5,
> + SCMI_CLOCK_RATE_GET = 0x6,
> + SCMI_CLOCK_CONFIG_SET = 0x7,
> +};
> +
> +#define SCMI_CLK_RATE_ASYNC_NOTIFY BIT(0)
> +#define SCMI_CLK_RATE_ASYNC_NORESP (BIT(0) | BIT(1))
> +#define SCMI_CLK_RATE_ROUND_DOWN 0
> +#define SCMI_CLK_RATE_ROUND_UP BIT(2)
> +#define SCMI_CLK_RATE_ROUND_CLOSEST BIT(3)
> +
> +struct scmi_clk_state_in {
> + u32 clock_id;
> + u32 attributes;
> +};
> +
> +struct scmi_clk_state_out {
> + s32 status;
> +};
> +
> +static int scmi_clk_gate(struct clk *clk, int enable)
> +{
> + struct scmi_clk_state_in in = {
> + .clock_id = clk->id,
> + .attributes = enable,
> + };
> + struct scmi_clk_state_out out;
> + struct scmi_msg scmi_msg = {
> + .protocol_id = SCMI_PROTOCOL_ID_CLOCK,
> + .message_id = SCMI_CLOCK_CONFIG_SET,
> + .in_msg = (u8 *)&in,
> + .in_msg_sz = sizeof(in),
> + .out_msg = (u8 *)&out,
> + .out_msg_sz = sizeof(out),
> + };
> + int rc;
Again please use 'ret'.
> +
> + rc = scmi_send_and_process_msg(clk->dev->parent, &scmi_msg);
> + if (rc)
> + return rc;
> +
> + return scmi_to_linux_errno(out.status);
> +}
> +
> +static int scmi_clk_enable(struct clk *clk)
> +{
> + return scmi_clk_gate(clk, 1);
> +}
> +
> +static int scmi_clk_disable(struct clk *clk)
> +{
> + return scmi_clk_gate(clk, 0);
> +}
> +
> +struct scmi_clk_rate_get_in {
> + u32 clock_id;
> +};
> +
> +struct scmi_clk_rate_get_out {
> + s32 status;
> + u32 rate_lsb;
> + u32 rate_msb;
> +};
> +
> +static ulong scmi_clk_get_rate(struct clk *clk)
> +{
> + struct scmi_clk_rate_get_in in = {
> + .clock_id = clk->id,
> + };
> + struct scmi_clk_rate_get_out out;
> + struct scmi_msg scmi_msg = {
> + .protocol_id = SCMI_PROTOCOL_ID_CLOCK,
> + .message_id = SCMI_CLOCK_RATE_GET,
> + .in_msg = (u8 *)&in,
> + .in_msg_sz = sizeof(in),
> + .out_msg = (u8 *)&out,
> + .out_msg_sz = sizeof(out),
> + };
> + int rc;
> +
> + rc = scmi_send_and_process_msg(clk->dev->parent, &scmi_msg);
> + if (rc)
> + return 0;
Why not rc?
> +
> + rc = scmi_to_linux_errno(out.status);
> + if (rc)
> + return 0;
> +
> + return (ulong)(((u64)out.rate_msb << 32) | out.rate_lsb);
This is odd. Can you use ulong instead of u64 to avoid two casts?
> +}
> +
> +struct scmi_clk_rate_set_in {
struct comment. I think these need to go in some sort of protocol header.
> + u32 clock_id;
> + u32 flags;
> + u32 rate_lsb;
> + u32 rate_msb;
> +};
> +
> +struct scmi_clk_rate_set_out {
> + s32 status;
> +};
> +
> +static ulong scmi_clk_set_rate(struct clk *clk, ulong rate)
> +{
> + struct scmi_clk_rate_set_in in = {
> + .clock_id = clk->id,
> + .flags = SCMI_CLK_RATE_ASYNC_NORESP |
> + SCMI_CLK_RATE_ROUND_CLOSEST,
> + .rate_lsb = (u32)rate,
> + .rate_msb = (u32)((u64)rate >> 32),
> + };
> + struct scmi_clk_rate_set_out out;
> + struct scmi_msg scmi_msg = {
> + .protocol_id = SCMI_PROTOCOL_ID_CLOCK,
> + .message_id = SCMI_CLOCK_RATE_SET,
> + .in_msg = (u8 *)&in,
> + .in_msg_sz = sizeof(in),
> + .out_msg = (u8 *)&out,
> + .out_msg_sz = sizeof(out),
> + };
> + int rc;
> +
> + rc = scmi_send_and_process_msg(clk->dev->parent, &scmi_msg);
> + if (rc)
> + return 0;
> +
> + return scmi_to_linux_errno(out.status);
> +}
> +
> +static const struct clk_ops scmi_clk_ops = {
> + .enable = scmi_clk_enable,
> + .disable = scmi_clk_disable,
> + .get_rate = scmi_clk_get_rate,
> + .set_rate = scmi_clk_set_rate,
> +};
> +
> +U_BOOT_DRIVER(scmi_clock) = {
> + .name = "scmi_clk",
> + .id = UCLASS_CLK,
> + .ops = &scmi_clk_ops,
> +};
> diff --git a/drivers/firmware/scmi.c b/drivers/firmware/scmi.c
> index fa8a91c3f3d..9f06718df51 100644
> --- a/drivers/firmware/scmi.c
> +++ b/drivers/firmware/scmi.c
> @@ -399,6 +399,9 @@ static int scmi_bind(struct udevice *dev)
> continue;
>
> switch (protocol_id) {
> + case SCMI_PROTOCOL_ID_CLOCK:
> + drv = DM_GET_DRIVER(scmi_clock);
> + break;
> default:
> dev_info(dev, "Ignore unsupported SCMI protocol %u\n",
> protocol_id);
> --
> 2.17.1
>
Can you add a sandbox test for this?
Regards,
Simon
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