2  * TI SYSCON regmap reset driver
4  * Copyright (C) 2015-2016 Texas Instruments Incorporated - https://www.ti.com/
23 #include <linux/reset-controller.h>
25 #include <dt-bindings/reset/ti-syscon.h>
28  * struct ti_syscon_reset_control - reset control structure
29  * @assert_offset: reset assert control register offset from syscon base
30  * @assert_bit: reset assert bit in the reset assert control register
31  * @deassert_offset: reset deassert control register offset from syscon base
32  * @deassert_bit: reset deassert bit in the reset deassert control register
33  * @status_offset: reset status register offset from syscon base
34  * @status_bit: reset status bit in the reset status register
35  * @flags: reset flag indicating how the (de)assert and status are handled
48  * struct ti_syscon_reset_data - reset controller information structure
49  * @rcdev: reset controller entity
50  * @regmap: regmap handle containing the memory-mapped reset registers
51  * @controls: array of reset controls
65  * ti_syscon_reset_assert() - assert device reset
66  * @rcdev: reset controller entity
67  * @id: ID of the reset to be asserted
69  * This function implements the reset driver op to assert a device's reset.
70  * This asserts the reset in a manner prescribed by the reset flags.
79 	unsigned int mask, value;  in ti_syscon_reset_assert()  local
81 	if (id >= data->nr_controls)  in ti_syscon_reset_assert()
82 		return -EINVAL;  in ti_syscon_reset_assert()
84 	control = &data->controls[id];  in ti_syscon_reset_assert()
86 	if (control->flags & ASSERT_NONE)  in ti_syscon_reset_assert()
87 		return -ENOTSUPP; /* assert not supported for this reset */  in ti_syscon_reset_assert()
89 	mask = BIT(control->assert_bit);  in ti_syscon_reset_assert()
90 	value = (control->flags & ASSERT_SET) ? mask : 0x0;  in ti_syscon_reset_assert()
92 	return regmap_update_bits(data->regmap, control->assert_offset, mask, value);  in ti_syscon_reset_assert()
96  * ti_syscon_reset_deassert() - deassert device reset
97  * @rcdev: reset controller entity
98  * @id: ID of reset to be deasserted
100  * This function implements the reset driver op to deassert a device's reset.
101  * This deasserts the reset in a manner prescribed by the reset flags.
110 	unsigned int mask, value;  in ti_syscon_reset_deassert()  local
112 	if (id >= data->nr_controls)  in ti_syscon_reset_deassert()
113 		return -EINVAL;  in ti_syscon_reset_deassert()
115 	control = &data->controls[id];  in ti_syscon_reset_deassert()
117 	if (control->flags & DEASSERT_NONE)  in ti_syscon_reset_deassert()
118 		return -ENOTSUPP; /* deassert not supported for this reset */  in ti_syscon_reset_deassert()
120 	mask = BIT(control->deassert_bit);  in ti_syscon_reset_deassert()
121 	value = (control->flags & DEASSERT_SET) ? mask : 0x0;  in ti_syscon_reset_deassert()
123 	return regmap_update_bits(data->regmap, control->deassert_offset, mask, value);  in ti_syscon_reset_deassert()
127  * ti_syscon_reset_status() - check device reset status
128  * @rcdev: reset controller entity
129  * @id: ID of the reset for which the status is being requested
131  * This function implements the reset driver op to return the status of a
132  * device's reset.
134  * Return: 0 if reset is deasserted, true if reset is asserted, else a
145 	if (id >= data->nr_controls)  in ti_syscon_reset_status()
146 		return -EINVAL;  in ti_syscon_reset_status()
148 	control = &data->controls[id];  in ti_syscon_reset_status()
150 	if (control->flags & STATUS_NONE)  in ti_syscon_reset_status()
151 		return -ENOTSUPP; /* status not supported for this reset */  in ti_syscon_reset_status()
153 	ret = regmap_read(data->regmap, control->status_offset, &reset_state);  in ti_syscon_reset_status()
157 	return !(reset_state & BIT(control->status_bit)) ==  in ti_syscon_reset_status()
158 		!(control->flags & STATUS_SET);  in ti_syscon_reset_status()
169 	struct device *dev = &pdev->dev;  in ti_syscon_reset_probe()
170 	struct device_node *np = dev->of_node;  in ti_syscon_reset_probe()
179 		return -ENOMEM;  in ti_syscon_reset_probe()
181 	regmap = syscon_node_to_regmap(np->parent);  in ti_syscon_reset_probe()
185 	list = of_get_property(np, "ti,reset-bits", &size);  in ti_syscon_reset_probe()
187 		dev_err(dev, "invalid DT reset description\n");  in ti_syscon_reset_probe()
188 		return -EINVAL;  in ti_syscon_reset_probe()
195 		return -ENOMEM;  in ti_syscon_reset_probe()
207 	data->rcdev.ops = &ti_syscon_reset_ops;  in ti_syscon_reset_probe()
208 	data->rcdev.owner = THIS_MODULE;  in ti_syscon_reset_probe()
209 	data->rcdev.of_node = np;  in ti_syscon_reset_probe()
210 	data->rcdev.nr_resets = nr_controls;  in ti_syscon_reset_probe()
211 	data->regmap = regmap;  in ti_syscon_reset_probe()
212 	data->controls = controls;  in ti_syscon_reset_probe()
213 	data->nr_controls = nr_controls;  in ti_syscon_reset_probe()
217 	return devm_reset_controller_register(dev, &data->rcdev);  in ti_syscon_reset_probe()
221 	{ .compatible = "ti,syscon-reset", },
229 		.name = "ti-syscon-reset",
236 MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");
237 MODULE_DESCRIPTION("TI SYSCON Regmap Reset Driver");