// SPDX-License-Identifier: GPL-2.0/* * ARM System Control and Management Interface (ARM SCMI) reset driver * * Copyright (C) 2019-2021 ARM Ltd. */ #include <linux/module.h>#include <linux/of.h>#include <linux/device.h>#include <linux/reset-controller.h>#include <linux/scmi_protocol.h> static const struct scmi_reset_proto_ops *reset_ops; /** * struct scmi_reset_data - reset controller information structure * @rcdev: reset controller entity * @ph: ARM SCMI protocol handle used for communication with system controller */struct scmi_reset_data {	struct reset_controller_dev rcdev;	const struct scmi_protocol_handle *ph;}; #define to_scmi_reset_data(p)	container_of((p), struct scmi_reset_data, rcdev)#define to_scmi_handle(p)	(to_scmi_reset_data(p)->ph) /** * 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 intscmi_reset_assert(struct reset_controller_dev *rcdev, unsigned long id){	const struct scmi_protocol_handle *ph = to_scmi_handle(rcdev); 	return reset_ops->assert(ph, 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 intscmi_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id){	const struct scmi_protocol_handle *ph = to_scmi_handle(rcdev); 	return reset_ops->deassert(ph, 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 intscmi_reset_reset(struct reset_controller_dev *rcdev, unsigned long id){	const struct scmi_protocol_handle *ph = to_scmi_handle(rcdev); 	return reset_ops->reset(ph, 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;	struct scmi_protocol_handle *ph; 	if (!handle)		return -ENODEV; 	reset_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_RESET, &ph);	if (IS_ERR(reset_ops))		return PTR_ERR(reset_ops); 	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 = reset_ops->num_domains_get(ph);	data->ph = ph; 	return devm_reset_controller_register(dev, &data->rcdev);} static const struct scmi_device_id scmi_id_table[] = {	{ SCMI_PROTOCOL_RESET, "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");