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132 lines
3.6 KiB
132 lines
3.6 KiB
// 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) 2019-2021 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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static const struct scmi_reset_proto_ops *reset_ops; |
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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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* @ph: ARM SCMI protocol 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_protocol_handle *ph; |
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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)->ph) |
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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_protocol_handle *ph = to_scmi_handle(rcdev); |
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return reset_ops->assert(ph, 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_protocol_handle *ph = to_scmi_handle(rcdev); |
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return reset_ops->deassert(ph, 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_protocol_handle *ph = to_scmi_handle(rcdev); |
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return reset_ops->reset(ph, 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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struct scmi_protocol_handle *ph; |
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if (!handle) |
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return -ENODEV; |
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reset_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_RESET, &ph); |
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if (IS_ERR(reset_ops)) |
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return PTR_ERR(reset_ops); |
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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 = reset_ops->num_domains_get(ph); |
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data->ph = ph; |
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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 <[email protected]>"); |
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MODULE_DESCRIPTION("ARM SCMI reset controller driver"); |
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MODULE_LICENSE("GPL v2");
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