forked from Minki/linux
34ce3c5e69
The scmi bus now has support to match the driver with devices not only based on their protocol id but also based on their device name if one is available. This was added to cater the need to support multiple devices and drivers for the same protocol. Let us add the name "reset" to scmi_device_id table in the driver so that in matches only with device with the same name and protocol id SCMI_PROTOCOL_RESET. Acked-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
126 lines
3.4 KiB
C
126 lines
3.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* ARM System Control and Management Interface (ARM SCMI) reset driver
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*
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* Copyright (C) 2019 ARM Ltd.
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*/
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/device.h>
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#include <linux/reset-controller.h>
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#include <linux/scmi_protocol.h>
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/**
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* struct scmi_reset_data - reset controller information structure
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* @rcdev: reset controller entity
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* @handle: ARM SCMI handle used for communication with system controller
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*/
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struct scmi_reset_data {
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struct reset_controller_dev rcdev;
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const struct scmi_handle *handle;
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};
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#define to_scmi_reset_data(p) container_of((p), struct scmi_reset_data, rcdev)
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#define to_scmi_handle(p) (to_scmi_reset_data(p)->handle)
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/**
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* scmi_reset_assert() - assert device reset
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* @rcdev: reset controller entity
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* @id: ID of the reset to be asserted
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*
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* This function implements the reset driver op to assert a device's reset
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* using the ARM SCMI protocol.
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*
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* Return: 0 for successful request, else a corresponding error value
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*/
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static int
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scmi_reset_assert(struct reset_controller_dev *rcdev, unsigned long id)
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{
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const struct scmi_handle *handle = to_scmi_handle(rcdev);
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return handle->reset_ops->assert(handle, id);
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}
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/**
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* scmi_reset_deassert() - deassert device reset
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* @rcdev: reset controller entity
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* @id: ID of the reset to be deasserted
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*
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* This function implements the reset driver op to deassert a device's reset
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* using the ARM SCMI protocol.
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*
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* Return: 0 for successful request, else a corresponding error value
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*/
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static int
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scmi_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id)
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{
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const struct scmi_handle *handle = to_scmi_handle(rcdev);
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return handle->reset_ops->deassert(handle, id);
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}
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/**
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* scmi_reset_reset() - reset the device
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* @rcdev: reset controller entity
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* @id: ID of the reset signal to be reset(assert + deassert)
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*
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* This function implements the reset driver op to trigger a device's
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* reset signal using the ARM SCMI protocol.
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*
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* Return: 0 for successful request, else a corresponding error value
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*/
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static int
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scmi_reset_reset(struct reset_controller_dev *rcdev, unsigned long id)
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{
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const struct scmi_handle *handle = to_scmi_handle(rcdev);
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return handle->reset_ops->reset(handle, id);
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}
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static const struct reset_control_ops scmi_reset_ops = {
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.assert = scmi_reset_assert,
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.deassert = scmi_reset_deassert,
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.reset = scmi_reset_reset,
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};
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static int scmi_reset_probe(struct scmi_device *sdev)
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{
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struct scmi_reset_data *data;
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struct device *dev = &sdev->dev;
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struct device_node *np = dev->of_node;
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const struct scmi_handle *handle = sdev->handle;
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if (!handle || !handle->reset_ops)
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return -ENODEV;
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data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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data->rcdev.ops = &scmi_reset_ops;
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data->rcdev.owner = THIS_MODULE;
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data->rcdev.of_node = np;
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data->rcdev.nr_resets = handle->reset_ops->num_domains_get(handle);
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data->handle = handle;
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return devm_reset_controller_register(dev, &data->rcdev);
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}
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static const struct scmi_device_id scmi_id_table[] = {
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{ SCMI_PROTOCOL_RESET, "reset" },
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{ },
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};
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MODULE_DEVICE_TABLE(scmi, scmi_id_table);
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static struct scmi_driver scmi_reset_driver = {
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.name = "scmi-reset",
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.probe = scmi_reset_probe,
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.id_table = scmi_id_table,
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};
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module_scmi_driver(scmi_reset_driver);
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MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
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MODULE_DESCRIPTION("ARM SCMI reset controller driver");
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MODULE_LICENSE("GPL v2");
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