// SPDX-License-Identifier: GPL-2.0-only/* * TI SYSCON regmap reset driver * * Copyright (C) 2015-2016 Texas Instruments Incorporated - https://www.ti.com/ *	Andrew F. Davis <afd@ti.com> *	Suman Anna <afd@ti.com> */ #include <linux/mfd/syscon.h>#include <linux/module.h>#include <linux/of.h>#include <linux/platform_device.h>#include <linux/regmap.h>#include <linux/reset-controller.h> #include <dt-bindings/reset/ti-syscon.h> /** * struct ti_syscon_reset_control - reset control structure * @assert_offset: reset assert control register offset from syscon base * @assert_bit: reset assert bit in the reset assert control register * @deassert_offset: reset deassert control register offset from syscon base * @deassert_bit: reset deassert bit in the reset deassert control register * @status_offset: reset status register offset from syscon base * @status_bit: reset status bit in the reset status register * @flags: reset flag indicating how the (de)assert and status are handled */struct ti_syscon_reset_control {	unsigned int assert_offset;	unsigned int assert_bit;	unsigned int deassert_offset;	unsigned int deassert_bit;	unsigned int status_offset;	unsigned int status_bit;	u32 flags;}; /** * struct ti_syscon_reset_data - reset controller information structure * @rcdev: reset controller entity * @regmap: regmap handle containing the memory-mapped reset registers * @controls: array of reset controls * @nr_controls: number of controls in control array */struct ti_syscon_reset_data {	struct reset_controller_dev rcdev;	struct regmap *regmap;	struct ti_syscon_reset_control *controls;	unsigned int nr_controls;}; #define to_ti_syscon_reset_data(_rcdev)	\	container_of(_rcdev, struct ti_syscon_reset_data, rcdev) /** * ti_syscon_reset_assert() - assert device reset * @rcdev: reset controller entity * @id: ID of the reset to be asserted * * This function implements the reset driver op to assert a device's reset. * This asserts the reset in a manner prescribed by the reset flags. * * Return: 0 for successful request, else a corresponding error value */static int ti_syscon_reset_assert(struct reset_controller_dev *rcdev,				  unsigned long id){	struct ti_syscon_reset_data *data = to_ti_syscon_reset_data(rcdev);	struct ti_syscon_reset_control *control;	unsigned int mask, value; 	if (id >= data->nr_controls)		return -EINVAL; 	control = &data->controls[id]; 	if (control->flags & ASSERT_NONE)		return -ENOTSUPP; /* assert not supported for this reset */ 	mask = BIT(control->assert_bit);	value = (control->flags & ASSERT_SET) ? mask : 0x0; 	return regmap_write_bits(data->regmap, control->assert_offset, mask, value);} /** * ti_syscon_reset_deassert() - deassert device reset * @rcdev: reset controller entity * @id: ID of reset to be deasserted * * This function implements the reset driver op to deassert a device's reset. * This deasserts the reset in a manner prescribed by the reset flags. * * Return: 0 for successful request, else a corresponding error value */static int ti_syscon_reset_deassert(struct reset_controller_dev *rcdev,				    unsigned long id){	struct ti_syscon_reset_data *data = to_ti_syscon_reset_data(rcdev);	struct ti_syscon_reset_control *control;	unsigned int mask, value; 	if (id >= data->nr_controls)		return -EINVAL; 	control = &data->controls[id]; 	if (control->flags & DEASSERT_NONE)		return -ENOTSUPP; /* deassert not supported for this reset */ 	mask = BIT(control->deassert_bit);	value = (control->flags & DEASSERT_SET) ? mask : 0x0; 	return regmap_write_bits(data->regmap, control->deassert_offset, mask, value);} /** * ti_syscon_reset_status() - check device reset status * @rcdev: reset controller entity * @id: ID of the reset for which the status is being requested * * This function implements the reset driver op to return the status of a * device's reset. * * Return: 0 if reset is deasserted, true if reset is asserted, else a * corresponding error value */static int ti_syscon_reset_status(struct reset_controller_dev *rcdev,				  unsigned long id){	struct ti_syscon_reset_data *data = to_ti_syscon_reset_data(rcdev);	struct ti_syscon_reset_control *control;	unsigned int reset_state;	int ret; 	if (id >= data->nr_controls)		return -EINVAL; 	control = &data->controls[id]; 	if (control->flags & STATUS_NONE)		return -ENOTSUPP; /* status not supported for this reset */ 	ret = regmap_read(data->regmap, control->status_offset, &reset_state);	if (ret)		return ret; 	return !(reset_state & BIT(control->status_bit)) ==		!(control->flags & STATUS_SET);} static const struct reset_control_ops ti_syscon_reset_ops = {	.assert		= ti_syscon_reset_assert,	.deassert	= ti_syscon_reset_deassert,	.status		= ti_syscon_reset_status,}; static int ti_syscon_reset_probe(struct platform_device *pdev){	struct device *dev = &pdev->dev;	struct device_node *np = dev->of_node;	struct ti_syscon_reset_data *data;	struct regmap *regmap;	const __be32 *list;	struct ti_syscon_reset_control *controls;	int size, nr_controls, i; 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);	if (!data)		return -ENOMEM; 	regmap = syscon_node_to_regmap(np->parent);	if (IS_ERR(regmap))		return PTR_ERR(regmap); 	list = of_get_property(np, "ti,reset-bits", &size);	if (!list || (size / sizeof(*list)) % 7 != 0) {		dev_err(dev, "invalid DT reset description\n");		return -EINVAL;	} 	nr_controls = (size / sizeof(*list)) / 7;	controls = devm_kcalloc(dev, nr_controls, sizeof(*controls),				GFP_KERNEL);	if (!controls)		return -ENOMEM; 	for (i = 0; i < nr_controls; i++) {		controls[i].assert_offset = be32_to_cpup(list++);		controls[i].assert_bit = be32_to_cpup(list++);		controls[i].deassert_offset = be32_to_cpup(list++);		controls[i].deassert_bit = be32_to_cpup(list++);		controls[i].status_offset = be32_to_cpup(list++);		controls[i].status_bit = be32_to_cpup(list++);		controls[i].flags = be32_to_cpup(list++);	} 	data->rcdev.ops = &ti_syscon_reset_ops;	data->rcdev.owner = THIS_MODULE;	data->rcdev.of_node = np;	data->rcdev.nr_resets = nr_controls;	data->regmap = regmap;	data->controls = controls;	data->nr_controls = nr_controls; 	return devm_reset_controller_register(dev, &data->rcdev);} static const struct of_device_id ti_syscon_reset_of_match[] = {	{ .compatible = "ti,syscon-reset", },	{ /* sentinel */ },};MODULE_DEVICE_TABLE(of, ti_syscon_reset_of_match); static struct platform_driver ti_syscon_reset_driver = {	.probe = ti_syscon_reset_probe,	.driver = {		.name = "ti-syscon-reset",		.of_match_table = ti_syscon_reset_of_match,	},};module_platform_driver(ti_syscon_reset_driver); MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");MODULE_DESCRIPTION("TI SYSCON Regmap Reset Driver");MODULE_LICENSE("GPL v2");