Subject: [PATCH 4/4] reset: add reset controller driver for SCMI agents

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://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%7C68ec2a92529 e49d46be608d82a6778a9%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0% 7C0%7C637305971181000613&sdata=NWnJw%2BYBsbC1zBkBdq9Jxh9 Crepk5JdxJlCxNl0diqA%3D&reserved=0 Signed-off-by: Etienne Carriere etienne.carriere@linaro.org

---

drivers/firmware/scmi.c | 3 ++ drivers/reset/Kconfig | 8 ++++ drivers/reset/Makefile | 1 + drivers/reset/reset-scmi.c | 86 ++++++++++++++++++++++++++++++++++++++ 4 files changed, 98 insertions(+) create mode 100644 drivers/reset/reset-scmi.c

diff --git a/drivers/firmware/scmi.c b/drivers/firmware/scmi.c index 9f06718df51..9be53a9cf11 100644 --- a/drivers/firmware/scmi.c +++ b/drivers/firmware/scmi.c @@ -402,6 +402,9 @@ 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 6d535612234..31bd4cd5b45 100644 --- a/drivers/reset/Kconfig +++ b/drivers/reset/Kconfig @@ -164,4 +164,12 @@ 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 8e0124b8dee..f3c0fbfd8f3 100644 --- a/drivers/reset/Makefile +++ b/drivers/reset/Makefile @@ -25,3 +25,4 @@ obj-$(CONFIG_RESET_HISILICON) += reset-hisilicon.o obj-$(CONFIG_RESET_IMX7) += reset-imx7.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 00000000000..e664d91d865 --- /dev/null +++ b/drivers/reset/reset-scmi.c @@ -0,0 +1,86 @@ +// 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>

+enum scmi_reset_domain_message_id {

• SCMI_RESET_DOMAIN_RESET = 0x4,

+};

+#define SCMI_RD_RESET_FLAG_ASSERT BIT(1) +#define SCMI_RD_RESET_FLAG_DEASSERT 0

+struct scmi_rd_reset_in {

• u32 domain_id;
• u32 flags;
• u32 reset_state;

+};

+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 rc;
• rc = scmi_send_and_process_msg(rst->dev->parent, &scmi_msg);
• if (rc)

• return rc;
  

• 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 *reset_ctl) {

• return 0;

+}

+static int scmi_reset_rfree(struct reset_ctl *reset_ctl) {

• 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,

+};

Regards, Peng.

2.17.1