diff options
Diffstat (limited to 'drivers/reset')
| -rw-r--r-- | drivers/reset/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/reset/Makefile | 1 | ||||
| -rw-r--r-- | drivers/reset/reset-scmi.c | 124 |
3 files changed, 136 insertions, 0 deletions
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 <linux/module.h> +#include <linux/of.h> +#include <linux/device.h> +#include <linux/reset-controller.h> +#include <linux/scmi_protocol.h> + +/** + * 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 <sudeep.holla@arm.com>"); +MODULE_DESCRIPTION("ARM SCMI reset controller driver"); +MODULE_LICENSE("GPL v2"); |