This change introduces a reset controller driver for SCMI agent devices. When SCMI agent and SCMI reset domain drivers are enabled, SCMI agent binds a reset controller device for each SCMI reset domain protocol devices enabled in the FDT.
SCMI reset driver is embedded upon CONFIG_RESET_SCMI=y. If enabled, CONFIG_SCMI_AGENT is also enabled.
SCMI Reset Domain 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: Simon Glass sjg@chromium.org Cc: Peng Fan peng.fan@nxp.com Cc: Sudeep Holla sudeep.holla@arm.com ---
Changes in v2: - Change reset request() method to at least check the reset domain exists by sending a SCMI RESET_DOMAIN_ATTRIBUTE message. - Add inline description for the several structures. - Patch v1 R-b tag not applied since the above changes in this v2. --- drivers/firmware/scmi.c | 3 + drivers/reset/Kconfig | 8 +++ drivers/reset/Makefile | 1 + drivers/reset/reset-scmi.c | 143 +++++++++++++++++++++++++++++++++++++ 4 files changed, 155 insertions(+) create mode 100644 drivers/reset/reset-scmi.c
diff --git a/drivers/firmware/scmi.c b/drivers/firmware/scmi.c index cddfa0bbc2..07a2b0f986 100644 --- a/drivers/firmware/scmi.c +++ b/drivers/firmware/scmi.c @@ -460,6 +460,9 @@ static int scmi_bind(struct udevice *dev) case SCMI_PROTOCOL_ID_CLOCK: drv = DM_GET_DRIVER(scmi_clock); break; + case SCMI_PROTOCOL_ID_RESET_DOMAIN: + drv = DM_GET_DRIVER(scmi_reset_domain); + break; default: dev_info(dev, "Ignore unsupported SCMI protocol %u\n", protocol_id); diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig index 253902ff57..ee5be0bc2f 100644 --- a/drivers/reset/Kconfig +++ b/drivers/reset/Kconfig @@ -173,4 +173,12 @@ config RESET_RASPBERRYPI relevant. This driver provides a reset controller capable of interfacing with RPi4's co-processor and model these firmware initialization routines as reset lines. + +config RESET_SCMI + bool "Enable SCMI reset domain driver" + select SCMI_FIRMWARE + help + Enable this option if you want to support reset controller + devices exposed by a SCMI agent based on SCMI reset domain + protocol communication with a SCMI server. endmenu diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile index 3c7f066ae3..625ec7168e 100644 --- a/drivers/reset/Makefile +++ b/drivers/reset/Makefile @@ -26,3 +26,4 @@ obj-$(CONFIG_RESET_IMX7) += reset-imx7.o obj-$(CONFIG_RESET_SIFIVE) += reset-sifive.o obj-$(CONFIG_RESET_SYSCON) += reset-syscon.o obj-$(CONFIG_RESET_RASPBERRYPI) += reset-raspberrypi.o +obj-$(CONFIG_RESET_SCMI) += reset-scmi.o diff --git a/drivers/reset/reset-scmi.c b/drivers/reset/reset-scmi.c new file mode 100644 index 0000000000..e8dabc9751 --- /dev/null +++ b/drivers/reset/reset-scmi.c @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2019-2020 Linaro Limited + */ +#include <common.h> +#include <dm.h> +#include <errno.h> +#include <reset-uclass.h> +#include <scmi.h> +#include <asm/types.h> + +#define SCMI_RD_NAME_LEN 16 + +#define SCMI_RD_RESET_FLAG_ASSERT BIT(1) +#define SCMI_RD_RESET_FLAG_DEASSERT 0 + +enum scmi_reset_domain_message_id { + SCMI_RESET_DOMAIN_ATTRIBUTES = 0x3, + SCMI_RESET_DOMAIN_RESET = 0x4, +}; + +/** + * struct scmi_rd_attr_in - Payload for RESET_DOMAIN_ATTRIBUTES message + * @domain_id: SCMI reset domain ID + */ +struct scmi_rd_attr_in { + u32 domain_id; +}; + +/** + * struct scmi_rd_attr_out - Payload for RESET_DOMAIN_ATTRIBUTES response + * @status: SCMI command status + * @attributes: Retrieved attributes of the reset domain + * @latency: Reset cycle max lantency + * @name: Reset domain name + */ +struct scmi_rd_attr_out { + s32 status; + u32 attributes; + u32 latency; + char name[SCMI_RD_NAME_LEN]; +}; + +/** + * struct scmi_rd_reset_in - Message payload for RESET command + * @domain_id: SCMI reset domain ID + * @flags: Flags for the reset request + * @reset_state: Reset target state + */ +struct scmi_rd_reset_in { + u32 domain_id; + u32 flags; + u32 reset_state; +}; + +/** + * struct scmi_rd_reset_out - Response payload for RESET command + * @status: SCMI command status + */ +struct scmi_rd_reset_out { + s32 status; +}; + +static int scmi_reset_set_state(struct reset_ctl *rst, int assert_not_deassert) +{ + struct scmi_rd_reset_in in = { + .domain_id = rst->id, + .flags = assert_not_deassert ? SCMI_RD_RESET_FLAG_ASSERT : + SCMI_RD_RESET_FLAG_DEASSERT, + .reset_state = 0, + }; + struct scmi_rd_reset_out out; + struct scmi_msg scmi_msg = { + .protocol_id = SCMI_PROTOCOL_ID_RESET_DOMAIN, + .message_id = SCMI_RESET_DOMAIN_RESET, + .in_msg = (u8 *)&in, + .in_msg_sz = sizeof(in), + .out_msg = (u8 *)&out, + .out_msg_sz = sizeof(out), + }; + int ret; + + ret = scmi_send_and_process_msg(rst->dev->parent, &scmi_msg); + if (ret) + return ret; + + return scmi_to_linux_errno(out.status); +} + +static int scmi_reset_assert(struct reset_ctl *rst) +{ + return scmi_reset_set_state(rst, SCMI_RD_RESET_FLAG_ASSERT); +} + +static int scmi_reset_deassert(struct reset_ctl *rst) +{ + return scmi_reset_set_state(rst, SCMI_RD_RESET_FLAG_DEASSERT); +} + +static int scmi_reset_request(struct reset_ctl *rst) +{ + struct scmi_rd_attr_in in = { + .domain_id = rst->id, + }; + struct scmi_rd_attr_out out; + struct scmi_msg scmi_msg = { + .protocol_id = SCMI_PROTOCOL_ID_RESET_DOMAIN, + .message_id = SCMI_RESET_DOMAIN_RESET, + .in_msg = (u8 *)&in, + .in_msg_sz = sizeof(in), + .out_msg = (u8 *)&out, + .out_msg_sz = sizeof(out), + }; + int ret; + + /* + * We don't really care about the attribute, just check + * the reset domain exists. + */ + ret = scmi_send_and_process_msg(rst->dev->parent, &scmi_msg); + if (ret) + return ret; + + return scmi_to_linux_errno(out.status); +} + +static int scmi_reset_rfree(struct reset_ctl *rst) +{ + return 0; +} + +static const struct reset_ops scmi_reset_domain_ops = { + .request = scmi_reset_request, + .rfree = scmi_reset_rfree, + .rst_assert = scmi_reset_assert, + .rst_deassert = scmi_reset_deassert, +}; + +U_BOOT_DRIVER(scmi_reset_domain) = { + .name = "scmi_reset_domain", + .id = UCLASS_RESET, + .ops = &scmi_reset_domain_ops, +};