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

Hi Etienne,

On Fri, 17 Jul 2020 at 09:43, Etienne Carriere etienne.carriere@linaro.org wrote:

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

---

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

Reviewed-by: Simon Glass sjg@chromium.org

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) +{

Do you actually need these two functions if they do nothing?

•   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,
  

+};

2.17.1

Regards, Simon