1 // SPDX-License-Identifier: GPL-2.0-only
3  * TI SYSCON regmap reset driver
5  * Copyright (C) 2015-2016 Texas Instruments Incorporated - https://www.ti.com/
15 #include <linux/reset-controller.h>
17 #include <dt-bindings/reset/ti-syscon.h>
20  * struct ti_syscon_reset_control - reset control structure
21  * @assert_offset: reset assert control register offset from syscon base
22  * @assert_bit: reset assert bit in the reset assert control register
23  * @deassert_offset: reset deassert control register offset from syscon base
24  * @deassert_bit: reset deassert bit in the reset deassert control register
25  * @status_offset: reset status register offset from syscon base
26  * @status_bit: reset status bit in the reset status register
27  * @flags: reset flag indicating how the (de)assert and status are handled
40  * struct ti_syscon_reset_data - reset controller information structure
41  * @rcdev: reset controller entity
42  * @regmap: regmap handle containing the memory-mapped reset registers
43  * @controls: array of reset controls
57  * ti_syscon_reset_assert() - assert device reset
58  * @rcdev: reset controller entity
59  * @id: ID of the reset to be asserted
61  * This function implements the reset driver op to assert a device's reset.
62  * This asserts the reset in a manner prescribed by the reset flags.
71 	unsigned int mask, value;  in ti_syscon_reset_assert()  local
73 	if (id >= data->nr_controls)  in ti_syscon_reset_assert()
74 		return -EINVAL;  in ti_syscon_reset_assert()
76 	control = &data->controls[id];  in ti_syscon_reset_assert()
78 	if (control->flags & ASSERT_NONE)  in ti_syscon_reset_assert()
79 		return -ENOTSUPP; /* assert not supported for this reset */  in ti_syscon_reset_assert()
81 	mask = BIT(control->assert_bit);  in ti_syscon_reset_assert()
82 	value = (control->flags & ASSERT_SET) ? mask : 0x0;  in ti_syscon_reset_assert()
84 	return regmap_write_bits(data->regmap, control->assert_offset, mask, value);  in ti_syscon_reset_assert()
88  * ti_syscon_reset_deassert() - deassert device reset
89  * @rcdev: reset controller entity
90  * @id: ID of reset to be deasserted
92  * This function implements the reset driver op to deassert a device's reset.
93  * This deasserts the reset in a manner prescribed by the reset flags.
102 	unsigned int mask, value;  in ti_syscon_reset_deassert()  local
104 	if (id >= data->nr_controls)  in ti_syscon_reset_deassert()
105 		return -EINVAL;  in ti_syscon_reset_deassert()
107 	control = &data->controls[id];  in ti_syscon_reset_deassert()
109 	if (control->flags & DEASSERT_NONE)  in ti_syscon_reset_deassert()
110 		return -ENOTSUPP; /* deassert not supported for this reset */  in ti_syscon_reset_deassert()
112 	mask = BIT(control->deassert_bit);  in ti_syscon_reset_deassert()
113 	value = (control->flags & DEASSERT_SET) ? mask : 0x0;  in ti_syscon_reset_deassert()
115 	return regmap_write_bits(data->regmap, control->deassert_offset, mask, value);  in ti_syscon_reset_deassert()
119  * ti_syscon_reset_status() - check device reset status
120  * @rcdev: reset controller entity
121  * @id: ID of the reset for which the status is being requested
123  * This function implements the reset driver op to return the status of a
124  * device's reset.
126  * Return: 0 if reset is deasserted, true if reset is asserted, else a
137 	if (id >= data->nr_controls)  in ti_syscon_reset_status()
138 		return -EINVAL;  in ti_syscon_reset_status()
140 	control = &data->controls[id];  in ti_syscon_reset_status()
142 	if (control->flags & STATUS_NONE)  in ti_syscon_reset_status()
143 		return -ENOTSUPP; /* status not supported for this reset */  in ti_syscon_reset_status()
145 	ret = regmap_read(data->regmap, control->status_offset, &reset_state);  in ti_syscon_reset_status()
149 	return !(reset_state & BIT(control->status_bit)) ==  in ti_syscon_reset_status()
150 		!(control->flags & STATUS_SET);  in ti_syscon_reset_status()
161 	struct device *dev = &pdev->dev;  in ti_syscon_reset_probe()
162 	struct device_node *np = dev->of_node;  in ti_syscon_reset_probe()
171 		return -ENOMEM;  in ti_syscon_reset_probe()
173 	regmap = syscon_node_to_regmap(np->parent);  in ti_syscon_reset_probe()
177 	list = of_get_property(np, "ti,reset-bits", &size);  in ti_syscon_reset_probe()
179 		dev_err(dev, "invalid DT reset description\n");  in ti_syscon_reset_probe()
180 		return -EINVAL;  in ti_syscon_reset_probe()
187 		return -ENOMEM;  in ti_syscon_reset_probe()
199 	data->rcdev.ops = &ti_syscon_reset_ops;  in ti_syscon_reset_probe()
200 	data->rcdev.owner = THIS_MODULE;  in ti_syscon_reset_probe()
201 	data->rcdev.of_node = np;  in ti_syscon_reset_probe()
202 	data->rcdev.nr_resets = nr_controls;  in ti_syscon_reset_probe()
203 	data->regmap = regmap;  in ti_syscon_reset_probe()
204 	data->controls = controls;  in ti_syscon_reset_probe()
205 	data->nr_controls = nr_controls;  in ti_syscon_reset_probe()
207 	return devm_reset_controller_register(dev, &data->rcdev);  in ti_syscon_reset_probe()
211 	{ .compatible = "ti,syscon-reset", },
219 		.name = "ti-syscon-reset",
226 MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");
227 MODULE_DESCRIPTION("TI SYSCON Regmap Reset Driver");