Subject: [PATCH 3/4] clk: add clock driver for SCMI agents

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://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdevelo per.arm.com%2Farchitectures%2Fsystem-architectures%2Fsoftware-standar ds%2Fscmi&data=02%7C01%7Cpeng.fan%40nxp.com%7C6a1c6d1e102 94e81e47708d82a6777b9%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0% 7C0%7C637305971176347870&sdata=4pKZGL17y7QUY%2Bi9XRutLOCe 5jBs1y9gMW7vNoUIcC0%3D&reserved=0 Signed-off-by: Etienne Carriere etienne.carriere@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
• 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;
• 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;
  

• rc = scmi_to_linux_errno(out.status);
• if (rc)

• return 0;
  

• return (ulong)(((u64)out.rate_msb << 32) | out.rate_lsb); }

+struct scmi_clk_rate_set_in {

• 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 |
  

This will use async, but how if sync?

Thanks, Peng.

• 	 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