1 // SPDX-License-Identifier: GPL-2.0+
3  * Texas Instruments System Control Interface (TI SCI) reset driver
5  * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
8  * Loosely based on Linux kernel reset-ti-sci.c...
14 #include <reset-uclass.h>
18  * struct ti_sci_reset_data - reset controller information structure
19  * @sci: TI SCI handle used for communication with system controller
22 	const struct ti_sci_handle *sci;  member
32 		return -ENOMEM;  in ti_sci_reset_probe()
35 	data->sci = ti_sci_get_handle(dev);  in ti_sci_reset_probe()
36 	if (IS_ERR(data->sci))  in ti_sci_reset_probe()
37 		return PTR_ERR(data->sci);  in ti_sci_reset_probe()
45 	debug("%s(rst=%p, args_count=%d)\n", __func__, rst, args->args_count);  in ti_sci_reset_of_xlate()
47 	if (args->args_count != 2) {  in ti_sci_reset_of_xlate()
48 		debug("Invalid args_count: %d\n", args->args_count);  in ti_sci_reset_of_xlate()
49 		return -EINVAL;  in ti_sci_reset_of_xlate()
53 	 * On TI SCI-based devices, the reset provider id field is used as a  in ti_sci_reset_of_xlate()
54 	 * device ID, and the data field is used as the associated reset mask.  in ti_sci_reset_of_xlate()
56 	rst->id = args->args[0];  in ti_sci_reset_of_xlate()
57 	rst->data = args->args[1];  in ti_sci_reset_of_xlate()
75  * ti_sci_reset_set() - program a device's reset
76  * @rst: Handle to a single reset signal
80  * reset using the TI SCI protocol. The device's reset is asserted if the
82  * The mechanism itself is a read-modify-write procedure, the current device
83  * reset register is read using a TI SCI device operation, the new value is
84  * set or un-set using the reset's mask, and the new reset value written by
85  * using another TI SCI device operation.
91 	struct ti_sci_reset_data *data = dev_get_priv(rst->dev);  in ti_sci_reset_set()
92 	const struct ti_sci_handle *sci = data->sci;  in ti_sci_reset_set()  local
93 	const struct ti_sci_dev_ops *dops = &sci->ops.dev_ops;  in ti_sci_reset_set()
97 	ret = dops->get_device_resets(sci, rst->id, &reset_state);  in ti_sci_reset_set()
99 		dev_err(rst->dev, "%s: get_device_resets failed (%d)\n",  in ti_sci_reset_set()
105 		reset_state |= rst->data;  in ti_sci_reset_set()
107 		reset_state &= ~rst->data;  in ti_sci_reset_set()
109 	ret = dops->set_device_resets(sci, rst->id, reset_state);  in ti_sci_reset_set()
111 		dev_err(rst->dev, "%s: set_device_resets failed (%d)\n",  in ti_sci_reset_set()
120  * ti_sci_reset_assert() - assert device reset
121  * @rst: Handle to a single reset signal
123  * This function implements the reset driver op to assert a device's reset
124  * using the TI SCI protocol. This invokes the function ti_sci_reset_set()
126  * argument set to true for asserting the reset.
137  * ti_sci_reset_deassert() - deassert device reset
138  * @rst: Handle to a single reset signal
140  * This function implements the reset driver op to deassert a device's reset
141  * using the TI SCI protocol. This invokes the function ti_sci_reset_set()
143  * argument set to false for deasserting the reset.
154  * ti_sci_reset_status() - check device reset status
155  * @rst: Handle to a single reset signal
157  * This function implements the reset driver op to return the status of a
158  * device's reset using the TI SCI protocol. The reset register value is read
159  * by invoking the TI SCI device operation .get_device_resets(), and the
160  * status of the specific reset is extracted and returned using this reset's
161  * reset mask.
163  * Return: 0 if reset is deasserted, or a non-zero value if reset is asserted
167 	struct ti_sci_reset_data *data = dev_get_priv(rst->dev);  in ti_sci_reset_status()
168 	const struct ti_sci_handle *sci = data->sci;  in ti_sci_reset_status()  local
169 	const struct ti_sci_dev_ops *dops = &sci->ops.dev_ops;  in ti_sci_reset_status()
175 	ret = dops->get_device_resets(sci, rst->id, &reset_state);  in ti_sci_reset_status()
177 		dev_err(rst->dev, "%s: get_device_resets failed (%d)\n",  in ti_sci_reset_status()
182 	return reset_state & rst->data;  in ti_sci_reset_status()
186 	{ .compatible = "ti,sci-reset", },
200 	.name = "ti-sci-reset",