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-standa... Signed-off-by: Etienne Carriere etienne.carriere@linaro.org Cc: Lukasz Majewski lukma@denx.de Cc: Simon Glass sjg@chromium.org Cc: Peng Fan peng.fan@nxp.com Cc: Sudeep Holla sudeep.holla@arm.com ---
Changes in v3:
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 | 3 + include/scmi_protocols.h | 78 ++++++++++++++++++ 5 files changed, 189 insertions(+) create mode 100644 drivers/clk/clk_scmi.c
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig index 6003e140b5..4dfbad7986 100644 --- a/drivers/clk/Kconfig +++ b/drivers/clk/Kconfig @@ -159,6 +159,14 @@ config CLK_CDCE9XX Enable the clock synthesizer driver for CDCE913/925/937/949 series of chips.
+config CLK_SCMI + bool "Enable SCMI clock driver" + depends on 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 cda4b4b605..d1e295ac7c 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -32,6 +32,7 @@ obj-$(CONFIG_CLK_MPC83XX) += mpc83xx_clk.o obj-$(CONFIG_CLK_OCTEON) += clk_octeon.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 0000000000..93a4819501 --- /dev/null +++ b/drivers/clk/clk_scmi.c @@ -0,0 +1,99 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2019-2020 Linaro Limited + */ +#include <common.h> +#include <clk-uclass.h> +#include <dm.h> +#include <scmi_agent.h> +#include <scmi_protocols.h> +#include <asm/types.h> + +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 msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_CLOCK, + SCMI_CLOCK_CONFIG_SET, + in, out); + int ret; + + ret = devm_scmi_process_msg(clk->dev->parent, &msg); + if (ret) + return ret; + + 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); +} + +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 msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_CLOCK, + SCMI_CLOCK_RATE_GET, + in, out); + int ret; + + ret = devm_scmi_process_msg(clk->dev->parent, &msg); + if (ret < 0) + return ret; + + ret = scmi_to_linux_errno(out.status); + if (ret < 0) + return ret; + + return (ulong)(((u64)out.rate_msb << 32) | out.rate_lsb); +} + +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_ROUND_CLOSEST, + .rate_lsb = (u32)rate, + .rate_msb = (u32)((u64)rate >> 32), + }; + struct scmi_clk_rate_set_out out; + struct scmi_msg msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_CLOCK, + SCMI_CLOCK_RATE_SET, + in, out); + int ret; + + ret = devm_scmi_process_msg(clk->dev->parent, &msg); + if (ret < 0) + return ret; + + ret = scmi_to_linux_errno(out.status); + if (ret < 0) + return ret; + + return scmi_clk_get_rate(clk); +} + +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/scmi_agent-uclass.c b/drivers/firmware/scmi/scmi_agent-uclass.c index 67a6f907c9..e1694eff3d 100644 --- a/drivers/firmware/scmi/scmi_agent-uclass.c +++ b/drivers/firmware/scmi/scmi_agent-uclass.c @@ -70,6 +70,9 @@ static int scmi_bind_protocols(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 %#x\n", protocol_id); diff --git a/include/scmi_protocols.h b/include/scmi_protocols.h index 86a2d109c8..4778bcfc47 100644 --- a/include/scmi_protocols.h +++ b/include/scmi_protocols.h @@ -7,6 +7,7 @@ #define _SCMI_PROTOCOLS_H
#include <linux/bitops.h> +#include <asm/types.h>
/* * Subset the SCMI protocols definition @@ -38,4 +39,81 @@ enum scmi_status_code { SCMI_PROTOCOL_ERROR = -10, };
+/* + * SCMI Clock Protocol + */ + +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 - Message payload for CLOCK_CONFIG_SET command + * @clock_id: SCMI clock ID + * @attributes: Attributes of the targets clock state + */ +struct scmi_clk_state_in { + u32 clock_id; + u32 attributes; +}; + +/** + * struct scmi_clk_state_out - Response payload for CLOCK_CONFIG_SET command + * @status: SCMI command status + */ +struct scmi_clk_state_out { + s32 status; +}; + +/** + * struct scmi_clk_state_in - Message payload for CLOCK_RATE_GET command + * @clock_id: SCMI clock ID + * @attributes: Attributes of the targets clock state + */ +struct scmi_clk_rate_get_in { + u32 clock_id; +}; + +/** + * struct scmi_clk_rate_get_out - Response payload for CLOCK_RATE_GET command + * @status: SCMI command status + * @rate_lsb: 32bit LSB of the clock rate in Hertz + * @rate_msb: 32bit MSB of the clock rate in Hertz + */ +struct scmi_clk_rate_get_out { + s32 status; + u32 rate_lsb; + u32 rate_msb; +}; + +/** + * struct scmi_clk_state_in - Message payload for CLOCK_RATE_SET command + * @clock_id: SCMI clock ID + * @flags: Flags for the clock rate set request + * @rate_lsb: 32bit LSB of the clock rate in Hertz + * @rate_msb: 32bit MSB of the clock rate in Hertz + */ +struct scmi_clk_rate_set_in { + u32 clock_id; + u32 flags; + u32 rate_lsb; + u32 rate_msb; +}; + +/** + * struct scmi_clk_rate_set_out - Response payload for CLOCK_RATE_SET command + * @status: SCMI command status + */ +struct scmi_clk_rate_set_out { + s32 status; +}; + #endif /* _SCMI_PROTOCOLS_H */