u-boot/drivers/reset/reset-scmi.c
Etienne Carriere 34d76fefb2 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://developer.arm.com/architectures/system-architectures/software-standards/scmi
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>
Reviewed-by: Simon Glass <sjg@chromium.org>
2020-09-30 11:55:23 -04:00

82 lines
1.8 KiB
C

// 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_agent.h>
#include <scmi_protocols.h>
#include <asm/types.h>
static int scmi_reset_set_level(struct reset_ctl *rst, bool assert_not_deassert)
{
struct scmi_rd_reset_in in = {
.domain_id = rst->id,
.flags = assert_not_deassert ? SCMI_RD_RESET_FLAG_ASSERT : 0,
.reset_state = 0,
};
struct scmi_rd_reset_out out;
struct scmi_msg msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_RESET_DOMAIN,
SCMI_RESET_DOMAIN_RESET,
in, out);
int ret;
ret = devm_scmi_process_msg(rst->dev->parent, &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_level(rst, true);
}
static int scmi_reset_deassert(struct reset_ctl *rst)
{
return scmi_reset_set_level(rst, false);
}
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 msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_RESET_DOMAIN,
SCMI_RESET_DOMAIN_ATTRIBUTES,
in, out);
int ret;
/*
* We don't really care about the attribute, just check
* the reset domain exists.
*/
ret = devm_scmi_process_msg(rst->dev->parent, &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,
};