From c8ae9c2da1cc5d18b6d51d10160508a3dc3436bf Mon Sep 17 00:00:00 2001 From: Sudeep Holla Date: Mon, 8 Jul 2019 09:41:08 +0100 Subject: reset: Add support for resets provided by SCMI On some ARM based systems, a separate Cortex-M based System Control Processor(SCP) provides the overall power, clock, reset and system control. System Control and Management Interface(SCMI) Message Protocol is defined for the communication between the Application Cores(AP) and the SCP. Adds support for the resets provided using SCMI protocol for performing reset management of various devices present on the SoC. Various reset functionalities are achieved by the means of different ARM SCMI device operations provided by the ARM SCMI framework. Reviewed-by: Philipp Zabel Signed-off-by: Sudeep Holla --- drivers/reset/Kconfig | 11 ++++ drivers/reset/Makefile | 1 + drivers/reset/reset-scmi.c | 124 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 136 insertions(+) create mode 100644 drivers/reset/reset-scmi.c (limited to 'drivers') diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig index 21efb7d39d62..4178ac11ba85 100644 --- a/drivers/reset/Kconfig +++ b/drivers/reset/Kconfig @@ -116,6 +116,17 @@ config RESET_QCOM_PDC to control reset signals provided by PDC for Modem, Compute, Display, GPU, Debug, AOP, Sensors, Audio, SP and APPS. +config RESET_SCMI + tristate "Reset driver controlled via ARM SCMI interface" + depends on ARM_SCMI_PROTOCOL || COMPILE_TEST + default ARM_SCMI_PROTOCOL + help + This driver provides support for reset signal/domains that are + controlled by firmware that implements the SCMI interface. + + This driver uses SCMI Message Protocol to interact with the + firmware controlling all the reset signals. + config RESET_SIMPLE bool "Simple Reset Controller Driver" if COMPILE_TEST default ARCH_STM32 || ARCH_STRATIX10 || ARCH_SUNXI || ARCH_ZX || ARCH_ASPEED || ARCH_BITMAIN diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile index 61456b8f659c..cf60ce526064 100644 --- a/drivers/reset/Makefile +++ b/drivers/reset/Makefile @@ -18,6 +18,7 @@ obj-$(CONFIG_RESET_OXNAS) += reset-oxnas.o obj-$(CONFIG_RESET_PISTACHIO) += reset-pistachio.o obj-$(CONFIG_RESET_QCOM_AOSS) += reset-qcom-aoss.o obj-$(CONFIG_RESET_QCOM_PDC) += reset-qcom-pdc.o +obj-$(CONFIG_RESET_SCMI) += reset-scmi.o obj-$(CONFIG_RESET_SIMPLE) += reset-simple.o obj-$(CONFIG_RESET_STM32MP157) += reset-stm32mp1.o obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o diff --git a/drivers/reset/reset-scmi.c b/drivers/reset/reset-scmi.c new file mode 100644 index 000000000000..c6d3c8427f14 --- /dev/null +++ b/drivers/reset/reset-scmi.c @@ -0,0 +1,124 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * ARM System Control and Management Interface (ARM SCMI) reset driver + * + * Copyright (C) 2019 ARM Ltd. + */ + +#include +#include +#include +#include +#include + +/** + * struct scmi_reset_data - reset controller information structure + * @rcdev: reset controller entity + * @handle: ARM SCMI handle used for communication with system controller + */ +struct scmi_reset_data { + struct reset_controller_dev rcdev; + const struct scmi_handle *handle; +}; + +#define to_scmi_reset_data(p) container_of((p), struct scmi_reset_data, rcdev) +#define to_scmi_handle(p) (to_scmi_reset_data(p)->handle) + +/** + * scmi_reset_assert() - assert device reset + * @rcdev: reset controller entity + * @id: ID of the reset to be asserted + * + * This function implements the reset driver op to assert a device's reset + * using the ARM SCMI protocol. + * + * Return: 0 for successful request, else a corresponding error value + */ +static int +scmi_reset_assert(struct reset_controller_dev *rcdev, unsigned long id) +{ + const struct scmi_handle *handle = to_scmi_handle(rcdev); + + return handle->reset_ops->assert(handle, id); +} + +/** + * scmi_reset_deassert() - deassert device reset + * @rcdev: reset controller entity + * @id: ID of the reset to be deasserted + * + * This function implements the reset driver op to deassert a device's reset + * using the ARM SCMI protocol. + * + * Return: 0 for successful request, else a corresponding error value + */ +static int +scmi_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id) +{ + const struct scmi_handle *handle = to_scmi_handle(rcdev); + + return handle->reset_ops->deassert(handle, id); +} + +/** + * scmi_reset_reset() - reset the device + * @rcdev: reset controller entity + * @id: ID of the reset signal to be reset(assert + deassert) + * + * This function implements the reset driver op to trigger a device's + * reset signal using the ARM SCMI protocol. + * + * Return: 0 for successful request, else a corresponding error value + */ +static int +scmi_reset_reset(struct reset_controller_dev *rcdev, unsigned long id) +{ + const struct scmi_handle *handle = to_scmi_handle(rcdev); + + return handle->reset_ops->reset(handle, id); +} + +static const struct reset_control_ops scmi_reset_ops = { + .assert = scmi_reset_assert, + .deassert = scmi_reset_deassert, + .reset = scmi_reset_reset, +}; + +static int scmi_reset_probe(struct scmi_device *sdev) +{ + struct scmi_reset_data *data; + struct device *dev = &sdev->dev; + struct device_node *np = dev->of_node; + const struct scmi_handle *handle = sdev->handle; + + if (!handle || !handle->reset_ops) + return -ENODEV; + + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->rcdev.ops = &scmi_reset_ops; + data->rcdev.owner = THIS_MODULE; + data->rcdev.of_node = np; + data->rcdev.nr_resets = handle->reset_ops->num_domains_get(handle); + + return devm_reset_controller_register(dev, &data->rcdev); +} + +static const struct scmi_device_id scmi_id_table[] = { + { SCMI_PROTOCOL_RESET }, + { }, +}; +MODULE_DEVICE_TABLE(scmi, scmi_id_table); + +static struct scmi_driver scmi_reset_driver = { + .name = "scmi-reset", + .probe = scmi_reset_probe, + .id_table = scmi_id_table, +}; +module_scmi_driver(scmi_reset_driver); + +MODULE_AUTHOR("Sudeep Holla "); +MODULE_DESCRIPTION("ARM SCMI reset controller driver"); +MODULE_LICENSE("GPL v2"); -- cgit v1.2.3