[mirror_ubuntu-hirsute-kernel.git] / drivers / gpio / gpio-raspberrypi-exp.c

// SPDX-License-Identifier: GPL-2.0+
/*
 *  Raspberry Pi 3 expander GPIO driver
 *
 *  Uses the firmware mailbox service to communicate with the
 *  GPIO expander on the VPU.
 *
 *  Copyright (C) 2017 Raspberry Pi Trading Ltd.
 */

#include <linux/err.h>
#include <linux/gpio/driver.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <soc/bcm2835/raspberrypi-firmware.h>

#define MODULE_NAME "raspberrypi-exp-gpio"
#define NUM_GPIO 8

#define RPI_EXP_GPIO_BASE	128

#define RPI_EXP_GPIO_DIR_IN	0
#define RPI_EXP_GPIO_DIR_OUT	1

struct rpi_exp_gpio {
	struct gpio_chip gc;
	struct rpi_firmware *fw;
};

/* VC4 firmware mailbox interface data structures */

struct gpio_set_config {
	u32 gpio;
	u32 direction;
	u32 polarity;
	u32 term_en;
	u32 term_pull_up;
	u32 state;
};

struct gpio_get_config {
	u32 gpio;
	u32 direction;
	u32 polarity;
	u32 term_en;
	u32 term_pull_up;
};

struct gpio_get_set_state {
	u32 gpio;
	u32 state;
};

static int rpi_exp_gpio_get_polarity(struct gpio_chip *gc, unsigned int off)
{
	struct rpi_exp_gpio *gpio;
	struct gpio_get_config get;
	int ret;

	gpio = gpiochip_get_data(gc);

	get.gpio = off + RPI_EXP_GPIO_BASE;	/* GPIO to update */

	ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_CONFIG,
				    &get, sizeof(get));
	if (ret || get.gpio != 0) {
		dev_err(gc->parent, "Failed to get GPIO %u config (%d %x)\n",
			off, ret, get.gpio);
		return ret ? ret : -EIO;
	}
	return get.polarity;
}

static int rpi_exp_gpio_dir_in(struct gpio_chip *gc, unsigned int off)
{
	struct rpi_exp_gpio *gpio;
	struct gpio_set_config set_in;
	int ret;

	gpio = gpiochip_get_data(gc);

	set_in.gpio = off + RPI_EXP_GPIO_BASE;	/* GPIO to update */
	set_in.direction = RPI_EXP_GPIO_DIR_IN;
	set_in.term_en = 0;		/* termination disabled */
	set_in.term_pull_up = 0;	/* n/a as termination disabled */
	set_in.state = 0;		/* n/a as configured as an input */

	ret = rpi_exp_gpio_get_polarity(gc, off);
	if (ret < 0)
		return ret;
	set_in.polarity = ret;		/* Retain existing setting */

	ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_SET_GPIO_CONFIG,
				    &set_in, sizeof(set_in));
	if (ret || set_in.gpio != 0) {
		dev_err(gc->parent, "Failed to set GPIO %u to input (%d %x)\n",
			off, ret, set_in.gpio);
		return ret ? ret : -EIO;
	}
	return 0;
}

static int rpi_exp_gpio_dir_out(struct gpio_chip *gc, unsigned int off, int val)
{
	struct rpi_exp_gpio *gpio;
	struct gpio_set_config set_out;
	int ret;

	gpio = gpiochip_get_data(gc);

	set_out.gpio = off + RPI_EXP_GPIO_BASE;	/* GPIO to update */
	set_out.direction = RPI_EXP_GPIO_DIR_OUT;
	set_out.term_en = 0;		/* n/a as an output */
	set_out.term_pull_up = 0;	/* n/a as termination disabled */
	set_out.state = val;		/* Output state */

	ret = rpi_exp_gpio_get_polarity(gc, off);
	if (ret < 0)
		return ret;
	set_out.polarity = ret;		/* Retain existing setting */

	ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_SET_GPIO_CONFIG,
				    &set_out, sizeof(set_out));
	if (ret || set_out.gpio != 0) {
		dev_err(gc->parent, "Failed to set GPIO %u to output (%d %x)\n",
			off, ret, set_out.gpio);
		return ret ? ret : -EIO;
	}
	return 0;
}

static int rpi_exp_gpio_get_direction(struct gpio_chip *gc, unsigned int off)
{
	struct rpi_exp_gpio *gpio;
	struct gpio_get_config get;
	int ret;

	gpio = gpiochip_get_data(gc);

	get.gpio = off + RPI_EXP_GPIO_BASE;	/* GPIO to update */

	ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_CONFIG,
				    &get, sizeof(get));
	if (ret || get.gpio != 0) {
		dev_err(gc->parent,
			"Failed to get GPIO %u config (%d %x)\n", off, ret,
			get.gpio);
		return ret ? ret : -EIO;
	}
	if (get.direction)
		return GPIO_LINE_DIRECTION_OUT;

	return GPIO_LINE_DIRECTION_IN;
}

static int rpi_exp_gpio_get(struct gpio_chip *gc, unsigned int off)
{
	struct rpi_exp_gpio *gpio;
	struct gpio_get_set_state get;
	int ret;

	gpio = gpiochip_get_data(gc);

	get.gpio = off + RPI_EXP_GPIO_BASE;	/* GPIO to update */
	get.state = 0;		/* storage for returned value */

	ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_STATE,
					 &get, sizeof(get));
	if (ret || get.gpio != 0) {
		dev_err(gc->parent,
			"Failed to get GPIO %u state (%d %x)\n", off, ret,
			get.gpio);
		return ret ? ret : -EIO;
	}
	return !!get.state;
}

static void rpi_exp_gpio_set(struct gpio_chip *gc, unsigned int off, int val)
{
	struct rpi_exp_gpio *gpio;
	struct gpio_get_set_state set;
	int ret;

	gpio = gpiochip_get_data(gc);

	set.gpio = off + RPI_EXP_GPIO_BASE;	/* GPIO to update */
	set.state = val;	/* Output state */

	ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_SET_GPIO_STATE,
					 &set, sizeof(set));
	if (ret || set.gpio != 0)
		dev_err(gc->parent,
			"Failed to set GPIO %u state (%d %x)\n", off, ret,
			set.gpio);
}

static int rpi_exp_gpio_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct device_node *fw_node;
	struct rpi_firmware *fw;
	struct rpi_exp_gpio *rpi_gpio;

	fw_node = of_get_parent(np);
	if (!fw_node) {
		dev_err(dev, "Missing firmware node\n");
		return -ENOENT;
	}

	fw = rpi_firmware_get(fw_node);
	of_node_put(fw_node);
	if (!fw)
		return -EPROBE_DEFER;

	rpi_gpio = devm_kzalloc(dev, sizeof(*rpi_gpio), GFP_KERNEL);
	if (!rpi_gpio)
		return -ENOMEM;

	rpi_gpio->fw = fw;
	rpi_gpio->gc.parent = dev;
	rpi_gpio->gc.label = MODULE_NAME;
	rpi_gpio->gc.owner = THIS_MODULE;
	rpi_gpio->gc.of_node = np;
	rpi_gpio->gc.base = -1;
	rpi_gpio->gc.ngpio = NUM_GPIO;

	rpi_gpio->gc.direction_input = rpi_exp_gpio_dir_in;
	rpi_gpio->gc.direction_output = rpi_exp_gpio_dir_out;
	rpi_gpio->gc.get_direction = rpi_exp_gpio_get_direction;
	rpi_gpio->gc.get = rpi_exp_gpio_get;
	rpi_gpio->gc.set = rpi_exp_gpio_set;
	rpi_gpio->gc.can_sleep = true;

	return devm_gpiochip_add_data(dev, &rpi_gpio->gc, rpi_gpio);
}

static const struct of_device_id rpi_exp_gpio_ids[] = {
	{ .compatible = "raspberrypi,firmware-gpio" },
	{ }
};
MODULE_DEVICE_TABLE(of, rpi_exp_gpio_ids);

static struct platform_driver rpi_exp_gpio_driver = {
	.driver	= {
		.name		= MODULE_NAME,
		.of_match_table	= of_match_ptr(rpi_exp_gpio_ids),
	},
	.probe	= rpi_exp_gpio_probe,
};
module_platform_driver(rpi_exp_gpio_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Dave Stevenson <dave.stevenson@raspberrypi.org>");
MODULE_DESCRIPTION("Raspberry Pi 3 expander GPIO driver");
MODULE_ALIAS("platform:rpi-exp-gpio");
Commit	Line	Data
a98d90e7 DS	1	// SPDX-License-Identifier: GPL-2.0+
	2	/*
	3	* Raspberry Pi 3 expander GPIO driver
	4	*
	5	* Uses the firmware mailbox service to communicate with the
	6	* GPIO expander on the VPU.
	7	*
	8	* Copyright (C) 2017 Raspberry Pi Trading Ltd.
	9	*/
	10
	11	#include <linux/err.h>
	12	#include <linux/gpio/driver.h>
	13	#include <linux/module.h>
	14	#include <linux/platform_device.h>
	15	#include <soc/bcm2835/raspberrypi-firmware.h>
	16
	17	#define MODULE_NAME "raspberrypi-exp-gpio"
	18	#define NUM_GPIO 8
	19
	20	#define RPI_EXP_GPIO_BASE 128
	21
	22	#define RPI_EXP_GPIO_DIR_IN 0
	23	#define RPI_EXP_GPIO_DIR_OUT 1
	24
	25	struct rpi_exp_gpio {
	26	struct gpio_chip gc;
	27	struct rpi_firmware *fw;
	28	};
	29
	30	/* VC4 firmware mailbox interface data structures */
	31
	32	struct gpio_set_config {
	33	u32 gpio;
	34	u32 direction;
	35	u32 polarity;
	36	u32 term_en;
	37	u32 term_pull_up;
	38	u32 state;
	39	};
	40
	41	struct gpio_get_config {
	42	u32 gpio;
	43	u32 direction;
	44	u32 polarity;
	45	u32 term_en;
	46	u32 term_pull_up;
	47	};
	48
	49	struct gpio_get_set_state {
	50	u32 gpio;
	51	u32 state;
	52	};
	53
	54	static int rpi_exp_gpio_get_polarity(struct gpio_chip *gc, unsigned int off)
	55	{
	56	struct rpi_exp_gpio *gpio;
	57	struct gpio_get_config get;
	58	int ret;
	59
	60	gpio = gpiochip_get_data(gc);
	61
	62	get.gpio = off + RPI_EXP_GPIO_BASE; /* GPIO to update */
	63
	64	ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_CONFIG,
65	&get, sizeof(get));
66	if (ret \|\| get.gpio != 0) {
67	dev_err(gc->parent, "Failed to get GPIO %u config (%d %x)\n",
68	off, ret, get.gpio);
69	return ret ? ret : -EIO;
70	}
71	return get.polarity;
72	}
73
74	static int rpi_exp_gpio_dir_in(struct gpio_chip *gc, unsigned int off)
75	{
76	struct rpi_exp_gpio *gpio;
77	struct gpio_set_config set_in;
78	int ret;
79
80	gpio = gpiochip_get_data(gc);
81
82	set_in.gpio = off + RPI_EXP_GPIO_BASE; /* GPIO to update */
83	set_in.direction = RPI_EXP_GPIO_DIR_IN;
84	set_in.term_en = 0; /* termination disabled */
85	set_in.term_pull_up = 0; /* n/a as termination disabled */
86	set_in.state = 0; /* n/a as configured as an input */
87
88	ret = rpi_exp_gpio_get_polarity(gc, off);
89	if (ret < 0)
90	return ret;
91	set_in.polarity = ret; /* Retain existing setting */
92
93	ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_SET_GPIO_CONFIG,
94	&set_in, sizeof(set_in));
95	if (ret \|\| set_in.gpio != 0) {
96	dev_err(gc->parent, "Failed to set GPIO %u to input (%d %x)\n",
97	off, ret, set_in.gpio);
98	return ret ? ret : -EIO;
99	}
100	return 0;
101	}
102
103	static int rpi_exp_gpio_dir_out(struct gpio_chip *gc, unsigned int off, int val)
104	{
105	struct rpi_exp_gpio *gpio;
106	struct gpio_set_config set_out;
107	int ret;
108
109	gpio = gpiochip_get_data(gc);
110
111	set_out.gpio = off + RPI_EXP_GPIO_BASE; /* GPIO to update */
112	set_out.direction = RPI_EXP_GPIO_DIR_OUT;
113	set_out.term_en = 0; /* n/a as an output */
114	set_out.term_pull_up = 0; /* n/a as termination disabled */
115	set_out.state = val; /* Output state */
116
117	ret = rpi_exp_gpio_get_polarity(gc, off);
118	if (ret < 0)
119	return ret;
120	set_out.polarity = ret; /* Retain existing setting */
121
122	ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_SET_GPIO_CONFIG,
123	&set_out, sizeof(set_out));
124	if (ret \|\| set_out.gpio != 0) {
125	dev_err(gc->parent, "Failed to set GPIO %u to output (%d %x)\n",
126	off, ret, set_out.gpio);
127	return ret ? ret : -EIO;
128	}
129	return 0;
130	}
131
132	static int rpi_exp_gpio_get_direction(struct gpio_chip *gc, unsigned int off)
133	{
134	struct rpi_exp_gpio *gpio;
135	struct gpio_get_config get;
136	int ret;
137
138	gpio = gpiochip_get_data(gc);
139
140	get.gpio = off + RPI_EXP_GPIO_BASE; /* GPIO to update */
141
142	ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_CONFIG,
143	&get, sizeof(get));
144	if (ret \|\| get.gpio != 0) {
145	dev_err(gc->parent,
146	"Failed to get GPIO %u config (%d %x)\n", off, ret,
147	get.gpio);
148	return ret ? ret : -EIO;
149	}
e42615ec MV	150	if (get.direction)
	151	return GPIO_LINE_DIRECTION_OUT;
	152
	153	return GPIO_LINE_DIRECTION_IN;
a98d90e7 DS	154	}
	155
	156	static int rpi_exp_gpio_get(struct gpio_chip *gc, unsigned int off)
	157	{
	158	struct rpi_exp_gpio *gpio;
	159	struct gpio_get_set_state get;
	160	int ret;
	161
	162	gpio = gpiochip_get_data(gc);
	163
	164	get.gpio = off + RPI_EXP_GPIO_BASE; /* GPIO to update */
	165	get.state = 0; /* storage for returned value */
	166
	167	ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_STATE,
	168	&get, sizeof(get));
	169	if (ret \|\| get.gpio != 0) {
	170	dev_err(gc->parent,
	171	"Failed to get GPIO %u state (%d %x)\n", off, ret,
	172	get.gpio);
	173	return ret ? ret : -EIO;
	174	}
	175	return !!get.state;
	176	}
	177
	178	static void rpi_exp_gpio_set(struct gpio_chip *gc, unsigned int off, int val)
	179	{
	180	struct rpi_exp_gpio *gpio;
	181	struct gpio_get_set_state set;
	182	int ret;
	183
	184	gpio = gpiochip_get_data(gc);
	185
	186	set.gpio = off + RPI_EXP_GPIO_BASE; /* GPIO to update */
	187	set.state = val; /* Output state */
	188
	189	ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_SET_GPIO_STATE,
	190	&set, sizeof(set));
	191	if (ret \|\| set.gpio != 0)
	192	dev_err(gc->parent,
	193	"Failed to set GPIO %u state (%d %x)\n", off, ret,
	194	set.gpio);
	195	}
	196
	197	static int rpi_exp_gpio_probe(struct platform_device *pdev)
	198	{
	199	struct device *dev = &pdev->dev;
	200	struct device_node *np = dev->of_node;
	201	struct device_node *fw_node;
	202	struct rpi_firmware *fw;
	203	struct rpi_exp_gpio *rpi_gpio;
	204
	205	fw_node = of_get_parent(np);
	206	if (!fw_node) {
	207	dev_err(dev, "Missing firmware node\n");
	208	return -ENOENT;
	209	}
	210
	211	fw = rpi_firmware_get(fw_node);
85af74c4	212	of_node_put(fw_node);
a98d90e7 DS	213	if (!fw)
	214	return -EPROBE_DEFER;
	215
	216	rpi_gpio = devm_kzalloc(dev, sizeof(*rpi_gpio), GFP_KERNEL);
	217	if (!rpi_gpio)
	218	return -ENOMEM;
	219
	220	rpi_gpio->fw = fw;
	221	rpi_gpio->gc.parent = dev;
	222	rpi_gpio->gc.label = MODULE_NAME;
	223	rpi_gpio->gc.owner = THIS_MODULE;
	224	rpi_gpio->gc.of_node = np;
	225	rpi_gpio->gc.base = -1;
	226	rpi_gpio->gc.ngpio = NUM_GPIO;
	227
	228	rpi_gpio->gc.direction_input = rpi_exp_gpio_dir_in;
	229	rpi_gpio->gc.direction_output = rpi_exp_gpio_dir_out;
	230	rpi_gpio->gc.get_direction = rpi_exp_gpio_get_direction;
	231	rpi_gpio->gc.get = rpi_exp_gpio_get;
	232	rpi_gpio->gc.set = rpi_exp_gpio_set;
	233	rpi_gpio->gc.can_sleep = true;
	234
	235	return devm_gpiochip_add_data(dev, &rpi_gpio->gc, rpi_gpio);
	236	}
	237
	238	static const struct of_device_id rpi_exp_gpio_ids[] = {
	239	{ .compatible = "raspberrypi,firmware-gpio" },
	240	{ }
	241	};
	242	MODULE_DEVICE_TABLE(of, rpi_exp_gpio_ids);
	243
	244	static struct platform_driver rpi_exp_gpio_driver = {
	245	.driver = {
	246	.name = MODULE_NAME,
	247	.of_match_table = of_match_ptr(rpi_exp_gpio_ids),
	248	},
	249	.probe = rpi_exp_gpio_probe,
	250	};
	251	module_platform_driver(rpi_exp_gpio_driver);
	252
	253	MODULE_LICENSE("GPL");
	254	MODULE_AUTHOR("Dave Stevenson <dave.stevenson@raspberrypi.org>");
	255	MODULE_DESCRIPTION("Raspberry Pi 3 expander GPIO driver");
	256	MODULE_ALIAS("platform:rpi-exp-gpio");