1// SPDX-License-Identifier: GPL-2.0-only
  2
  3#include <linux/types.h>
  4#include <linux/io.h>
  5#include <linux/bits.h>
  6#include <linux/gpio/driver.h>
  7#include <linux/mod_devicetable.h>
  8#include <linux/module.h>
  9#include <linux/platform_device.h>
 10#include <linux/property.h>
 11
 12#define AIROHA_GPIO_MAX		32
 13
 14/**
 15 * struct airoha_gpio_ctrl - Airoha GPIO driver data
 16 * @gc: Associated gpio_chip instance.
 17 * @data: The data register.
 18 * @dir: [0] The direction register for the lower 16 pins.
 19 * [1]: The direction register for the higher 16 pins.
 20 * @output: The output enable register.
 21 */
 22struct airoha_gpio_ctrl {
 23	struct gpio_chip gc;
 24	void __iomem *data;
 25	void __iomem *dir[2];
 26	void __iomem *output;
 27};
 28
 29static struct airoha_gpio_ctrl *gc_to_ctrl(struct gpio_chip *gc)
 30{
 31	return container_of(gc, struct airoha_gpio_ctrl, gc);
 32}
 33
 34static int airoha_dir_set(struct gpio_chip *gc, unsigned int gpio,
 35			  int val, int out)
 36{
 37	struct airoha_gpio_ctrl *ctrl = gc_to_ctrl(gc);
 38	u32 dir = ioread32(ctrl->dir[gpio / 16]);
 39	u32 output = ioread32(ctrl->output);
 40	u32 mask = BIT((gpio % 16) * 2);
 41
 42	if (out) {
 43		dir |= mask;
 44		output |= BIT(gpio);
 45	} else {
 46		dir &= ~mask;
 47		output &= ~BIT(gpio);
 48	}
 49
 50	iowrite32(dir, ctrl->dir[gpio / 16]);
 51
 52	if (out)
 53		gc->set(gc, gpio, val);
 54
 55	iowrite32(output, ctrl->output);
 56
 57	return 0;
 58}
 59
 60static int airoha_dir_out(struct gpio_chip *gc, unsigned int gpio,
 61			  int val)
 62{
 63	return airoha_dir_set(gc, gpio, val, 1);
 64}
 65
 66static int airoha_dir_in(struct gpio_chip *gc, unsigned int gpio)
 67{
 68	return airoha_dir_set(gc, gpio, 0, 0);
 69}
 70
 71static int airoha_get_dir(struct gpio_chip *gc, unsigned int gpio)
 72{
 73	struct airoha_gpio_ctrl *ctrl = gc_to_ctrl(gc);
 74	u32 dir = ioread32(ctrl->dir[gpio / 16]);
 75	u32 mask = BIT((gpio % 16) * 2);
 76
 77	return (dir & mask) ? GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
 78}
 79
 80static int airoha_gpio_probe(struct platform_device *pdev)
 81{
 82	struct device *dev = &pdev->dev;
 83	struct airoha_gpio_ctrl *ctrl;
 84	int err;
 85
 86	ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
 87	if (!ctrl)
 88		return -ENOMEM;
 89
 90	ctrl->data = devm_platform_ioremap_resource(pdev, 0);
 91	if (IS_ERR(ctrl->data))
 92		return PTR_ERR(ctrl->data);
 93
 94	ctrl->dir[0] = devm_platform_ioremap_resource(pdev, 1);
 95	if (IS_ERR(ctrl->dir[0]))
 96		return PTR_ERR(ctrl->dir[0]);
 97
 98	ctrl->dir[1] = devm_platform_ioremap_resource(pdev, 2);
 99	if (IS_ERR(ctrl->dir[1]))
100		return PTR_ERR(ctrl->dir[1]);
101
102	ctrl->output = devm_platform_ioremap_resource(pdev, 3);
103	if (IS_ERR(ctrl->output))
104		return PTR_ERR(ctrl->output);
105
106	err = bgpio_init(&ctrl->gc, dev, 4, ctrl->data, NULL,
107			 NULL, NULL, NULL, 0);
108	if (err)
109		return dev_err_probe(dev, err, "unable to init generic GPIO");
110
111	ctrl->gc.ngpio = AIROHA_GPIO_MAX;
112	ctrl->gc.owner = THIS_MODULE;
113	ctrl->gc.direction_output = airoha_dir_out;
114	ctrl->gc.direction_input = airoha_dir_in;
115	ctrl->gc.get_direction = airoha_get_dir;
116
117	return devm_gpiochip_add_data(dev, &ctrl->gc, ctrl);
118}
119
120static const struct of_device_id airoha_gpio_of_match[] = {
121	{ .compatible = "airoha,en7523-gpio" },
122	{ }
123};
124MODULE_DEVICE_TABLE(of, airoha_gpio_of_match);
125
126static struct platform_driver airoha_gpio_driver = {
127	.driver = {
128		.name = "airoha-gpio",
129		.of_match_table	= airoha_gpio_of_match,
130	},
131	.probe = airoha_gpio_probe,
132};
133module_platform_driver(airoha_gpio_driver);
134
135MODULE_DESCRIPTION("Airoha GPIO support");
136MODULE_AUTHOR("John Crispin <john@phrozen.org>");
137MODULE_LICENSE("GPL v2");