[linux.git] / drivers / gpio / gpio-sama5d2-piobu.c

// SPDX-License-Identifier: GPL-2.0
/*
 * SAMA5D2 PIOBU GPIO controller
 *
 * Copyright (C) 2018 Microchip Technology Inc. and its subsidiaries
 *
 * Author: Andrei Stefanescu <[email protected]>
 *
 */
#include <linux/bits.h>
#include <linux/gpio/driver.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

#define PIOBU_NUM 8
#define PIOBU_REG_SIZE 4

/*
 * backup mode protection register for tamper detection
 * normal mode protection register for tamper detection
 * wakeup signal generation
 */
#define PIOBU_BMPR 0x7C
#define PIOBU_NMPR 0x80
#define PIOBU_WKPR 0x90

#define PIOBU_BASE 0x18 /* PIOBU offset from SECUMOD base register address. */

#define PIOBU_DET_OFFSET 16

/* In the datasheet this bit is called OUTPUT */
#define PIOBU_DIRECTION BIT(8)
#define PIOBU_OUT BIT(8)
#define PIOBU_IN 0

#define PIOBU_SOD BIT(9)
#define PIOBU_PDS BIT(10)

#define PIOBU_HIGH BIT(9)
#define PIOBU_LOW 0

struct sama5d2_piobu {
	struct gpio_chip chip;
	struct regmap *regmap;
};

/*
 * sama5d2_piobu_setup_pin() - prepares a pin for set_direction call
 *
 * Do not consider pin for tamper detection (normal and backup modes)
 * Do not consider pin as tamper wakeup interrupt source
 */
static int sama5d2_piobu_setup_pin(struct gpio_chip *chip, unsigned int pin)
{
	int ret;
	struct sama5d2_piobu *piobu = container_of(chip, struct sama5d2_piobu,
						   chip);
	unsigned int mask = BIT(PIOBU_DET_OFFSET + pin);

	ret = regmap_update_bits(piobu->regmap, PIOBU_BMPR, mask, 0);
	if (ret)
		return ret;

	ret = regmap_update_bits(piobu->regmap, PIOBU_NMPR, mask, 0);
	if (ret)
		return ret;

	return regmap_update_bits(piobu->regmap, PIOBU_WKPR, mask, 0);
}

/*
 * sama5d2_piobu_write_value() - writes value & mask at the pin's PIOBU register
 */
static int sama5d2_piobu_write_value(struct gpio_chip *chip, unsigned int pin,
				     unsigned int mask, unsigned int value)
{
	int reg;
	struct sama5d2_piobu *piobu = container_of(chip, struct sama5d2_piobu,
						   chip);

	reg = PIOBU_BASE + pin * PIOBU_REG_SIZE;

	return regmap_update_bits(piobu->regmap, reg, mask, value);
}

/*
 * sama5d2_piobu_read_value() - read the value with masking from the pin's PIOBU
 *			      register
 */
static int sama5d2_piobu_read_value(struct gpio_chip *chip, unsigned int pin,
				    unsigned int mask)
{
	struct sama5d2_piobu *piobu = container_of(chip, struct sama5d2_piobu,
						   chip);
	unsigned int val, reg;
	int ret;

	reg = PIOBU_BASE + pin * PIOBU_REG_SIZE;
	ret = regmap_read(piobu->regmap, reg, &val);
	if (ret < 0)
		return ret;

	return val & mask;
}

/*
 * sama5d2_piobu_get_direction() - gpiochip get_direction
 */
static int sama5d2_piobu_get_direction(struct gpio_chip *chip,
				       unsigned int pin)
{
	int ret = sama5d2_piobu_read_value(chip, pin, PIOBU_DIRECTION);

	if (ret < 0)
		return ret;

	return (ret == PIOBU_IN) ? GPIO_LINE_DIRECTION_IN :
				   GPIO_LINE_DIRECTION_OUT;
}

/*
 * sama5d2_piobu_direction_input() - gpiochip direction_input
 */
static int sama5d2_piobu_direction_input(struct gpio_chip *chip,
					 unsigned int pin)
{
	return sama5d2_piobu_write_value(chip, pin, PIOBU_DIRECTION, PIOBU_IN);
}

/*
 * sama5d2_piobu_direction_output() - gpiochip direction_output
 */
static int sama5d2_piobu_direction_output(struct gpio_chip *chip,
					  unsigned int pin, int value)
{
	unsigned int val = PIOBU_OUT;

	if (value)
		val |= PIOBU_HIGH;

	return sama5d2_piobu_write_value(chip, pin, PIOBU_DIRECTION | PIOBU_SOD,
					 val);
}

/*
 * sama5d2_piobu_get() - gpiochip get
 */
static int sama5d2_piobu_get(struct gpio_chip *chip, unsigned int pin)
{
	/* if pin is input, read value from PDS else read from SOD */
	int ret = sama5d2_piobu_get_direction(chip, pin);

	if (ret == GPIO_LINE_DIRECTION_IN)
		ret = sama5d2_piobu_read_value(chip, pin, PIOBU_PDS);
	else if (ret == GPIO_LINE_DIRECTION_OUT)
		ret = sama5d2_piobu_read_value(chip, pin, PIOBU_SOD);

	if (ret < 0)
		return ret;

	return !!ret;
}

/*
 * sama5d2_piobu_set() - gpiochip set
 */
static void sama5d2_piobu_set(struct gpio_chip *chip, unsigned int pin,
			      int value)
{
	if (!value)
		value = PIOBU_LOW;
	else
		value = PIOBU_HIGH;

	sama5d2_piobu_write_value(chip, pin, PIOBU_SOD, value);
}

static int sama5d2_piobu_probe(struct platform_device *pdev)
{
	struct sama5d2_piobu *piobu;
	int ret, i;

	piobu = devm_kzalloc(&pdev->dev, sizeof(*piobu), GFP_KERNEL);
	if (!piobu)
		return -ENOMEM;

	platform_set_drvdata(pdev, piobu);
	piobu->chip.label = pdev->name;
	piobu->chip.parent = &pdev->dev;
	piobu->chip.of_node = pdev->dev.of_node;
	piobu->chip.owner = THIS_MODULE,
	piobu->chip.get_direction = sama5d2_piobu_get_direction,
	piobu->chip.direction_input = sama5d2_piobu_direction_input,
	piobu->chip.direction_output = sama5d2_piobu_direction_output,
	piobu->chip.get = sama5d2_piobu_get,
	piobu->chip.set = sama5d2_piobu_set,
	piobu->chip.base = -1,
	piobu->chip.ngpio = PIOBU_NUM,
	piobu->chip.can_sleep = 0,

	piobu->regmap = syscon_node_to_regmap(pdev->dev.of_node);
	if (IS_ERR(piobu->regmap)) {
		dev_err(&pdev->dev, "Failed to get syscon regmap %ld\n",
			PTR_ERR(piobu->regmap));
		return PTR_ERR(piobu->regmap);
	}

	ret = devm_gpiochip_add_data(&pdev->dev, &piobu->chip, piobu);
	if (ret) {
		dev_err(&pdev->dev, "Failed to add gpiochip %d\n", ret);
		return ret;
	}

	for (i = 0; i < PIOBU_NUM; ++i) {
		ret = sama5d2_piobu_setup_pin(&piobu->chip, i);
		if (ret) {
			dev_err(&pdev->dev, "Failed to setup pin: %d %d\n",
				i, ret);
			return ret;
		}
	}

	return 0;
}

static const struct of_device_id sama5d2_piobu_ids[] = {
	{ .compatible = "atmel,sama5d2-secumod" },
	{},
};
MODULE_DEVICE_TABLE(of, sama5d2_piobu_ids);

static struct platform_driver sama5d2_piobu_driver = {
	.driver = {
		.name		= "sama5d2-piobu",
		.of_match_table	= of_match_ptr(sama5d2_piobu_ids)
	},
	.probe = sama5d2_piobu_probe,
};

module_platform_driver(sama5d2_piobu_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("SAMA5D2 PIOBU controller driver");
MODULE_AUTHOR("Andrei Stefanescu <[email protected]>");
Commit	Line	Data
fb0b35d3 AS	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* SAMA5D2 PIOBU GPIO controller
	4	*
	5	* Copyright (C) 2018 Microchip Technology Inc. and its subsidiaries
	6	*
	7	* Author: Andrei Stefanescu <[email protected]>
	8	*
	9	*/
	10	#include <linux/bits.h>
	11	#include <linux/gpio/driver.h>
	12	#include <linux/init.h>
	13	#include <linux/kernel.h>
	14	#include <linux/mfd/syscon.h>
	15	#include <linux/module.h>
	16	#include <linux/of.h>
	17	#include <linux/platform_device.h>
	18	#include <linux/regmap.h>
	19
	20	#define PIOBU_NUM 8
	21	#define PIOBU_REG_SIZE 4
	22
	23	/*
	24	* backup mode protection register for tamper detection
	25	* normal mode protection register for tamper detection
	26	* wakeup signal generation
	27	*/
	28	#define PIOBU_BMPR 0x7C
	29	#define PIOBU_NMPR 0x80
	30	#define PIOBU_WKPR 0x90
	31
	32	#define PIOBU_BASE 0x18 /* PIOBU offset from SECUMOD base register address. */
	33
	34	#define PIOBU_DET_OFFSET 16
	35
	36	/* In the datasheet this bit is called OUTPUT */
	37	#define PIOBU_DIRECTION BIT(8)
	38	#define PIOBU_OUT BIT(8)
	39	#define PIOBU_IN 0
	40
	41	#define PIOBU_SOD BIT(9)
	42	#define PIOBU_PDS BIT(10)
	43
	44	#define PIOBU_HIGH BIT(9)
	45	#define PIOBU_LOW 0
	46
	47	struct sama5d2_piobu {
	48	struct gpio_chip chip;
	49	struct regmap *regmap;
	50	};
	51
392a5846	52	/*
fb0b35d3 AS	53	* sama5d2_piobu_setup_pin() - prepares a pin for set_direction call
	54	*
	55	* Do not consider pin for tamper detection (normal and backup modes)
	56	* Do not consider pin as tamper wakeup interrupt source
	57	*/
	58	static int sama5d2_piobu_setup_pin(struct gpio_chip *chip, unsigned int pin)
	59	{
	60	int ret;
	61	struct sama5d2_piobu *piobu = container_of(chip, struct sama5d2_piobu,
	62	chip);
	63	unsigned int mask = BIT(PIOBU_DET_OFFSET + pin);
	64
	65	ret = regmap_update_bits(piobu->regmap, PIOBU_BMPR, mask, 0);
	66	if (ret)
	67	return ret;
	68
	69	ret = regmap_update_bits(piobu->regmap, PIOBU_NMPR, mask, 0);
	70	if (ret)
	71	return ret;
	72
	73	return regmap_update_bits(piobu->regmap, PIOBU_WKPR, mask, 0);
	74	}
	75
392a5846	76	/*
fb0b35d3 AS	77	* sama5d2_piobu_write_value() - writes value & mask at the pin's PIOBU register
	78	*/
	79	static int sama5d2_piobu_write_value(struct gpio_chip *chip, unsigned int pin,
	80	unsigned int mask, unsigned int value)
	81	{
	82	int reg;
	83	struct sama5d2_piobu *piobu = container_of(chip, struct sama5d2_piobu,
	84	chip);
	85
	86	reg = PIOBU_BASE + pin * PIOBU_REG_SIZE;
	87
	88	return regmap_update_bits(piobu->regmap, reg, mask, value);
	89	}
	90
392a5846	91	/*
fb0b35d3 AS	92	* sama5d2_piobu_read_value() - read the value with masking from the pin's PIOBU
	93	* register
	94	*/
	95	static int sama5d2_piobu_read_value(struct gpio_chip *chip, unsigned int pin,
	96	unsigned int mask)
	97	{
	98	struct sama5d2_piobu *piobu = container_of(chip, struct sama5d2_piobu,
	99	chip);
	100	unsigned int val, reg;
	101	int ret;
	102
	103	reg = PIOBU_BASE + pin * PIOBU_REG_SIZE;
	104	ret = regmap_read(piobu->regmap, reg, &val);
	105	if (ret < 0)
	106	return ret;
	107
	108	return val & mask;
	109	}
	110
392a5846	111	/*
fb0b35d3 AS	112	* sama5d2_piobu_get_direction() - gpiochip get_direction
	113	*/
	114	static int sama5d2_piobu_get_direction(struct gpio_chip *chip,
	115	unsigned int pin)
	116	{
	117	int ret = sama5d2_piobu_read_value(chip, pin, PIOBU_DIRECTION);
	118
	119	if (ret < 0)
	120	return ret;
	121
e42615ec MV	122	return (ret == PIOBU_IN) ? GPIO_LINE_DIRECTION_IN :
e42615ec MV	123	GPIO_LINE_DIRECTION_OUT;
fb0b35d3 AS	124	}
fb0b35d3 AS	125
392a5846	126	/*
fb0b35d3 AS	127	* sama5d2_piobu_direction_input() - gpiochip direction_input
	128	*/
	129	static int sama5d2_piobu_direction_input(struct gpio_chip *chip,
	130	unsigned int pin)
	131	{
e4889362	132	return sama5d2_piobu_write_value(chip, pin, PIOBU_DIRECTION, PIOBU_IN);
fb0b35d3 AS	133	}
fb0b35d3 AS	134
392a5846	135	/*
fb0b35d3 AS	136	* sama5d2_piobu_direction_output() - gpiochip direction_output
	137	*/
	138	static int sama5d2_piobu_direction_output(struct gpio_chip *chip,
	139	unsigned int pin, int value)
	140	{
e4889362 AL	141	unsigned int val = PIOBU_OUT;
	142
	143	if (value)
	144	val \|= PIOBU_HIGH;
	145
	146	return sama5d2_piobu_write_value(chip, pin, PIOBU_DIRECTION \| PIOBU_SOD,
	147	val);
fb0b35d3 AS	148	}
fb0b35d3 AS	149
392a5846	150	/*
fb0b35d3 AS	151	* sama5d2_piobu_get() - gpiochip get
	152	*/
	153	static int sama5d2_piobu_get(struct gpio_chip *chip, unsigned int pin)
	154	{
	155	/* if pin is input, read value from PDS else read from SOD */
	156	int ret = sama5d2_piobu_get_direction(chip, pin);
	157
e42615ec	158	if (ret == GPIO_LINE_DIRECTION_IN)
fb0b35d3	159	ret = sama5d2_piobu_read_value(chip, pin, PIOBU_PDS);
e42615ec	160	else if (ret == GPIO_LINE_DIRECTION_OUT)
fb0b35d3 AS	161	ret = sama5d2_piobu_read_value(chip, pin, PIOBU_SOD);
	162
	163	if (ret < 0)
	164	return ret;
	165
	166	return !!ret;
	167	}
	168
392a5846	169	/*
fb0b35d3 AS	170	* sama5d2_piobu_set() - gpiochip set
	171	*/
	172	static void sama5d2_piobu_set(struct gpio_chip *chip, unsigned int pin,
	173	int value)
	174	{
	175	if (!value)
	176	value = PIOBU_LOW;
	177	else
	178	value = PIOBU_HIGH;
	179
	180	sama5d2_piobu_write_value(chip, pin, PIOBU_SOD, value);
	181	}
	182
	183	static int sama5d2_piobu_probe(struct platform_device *pdev)
	184	{
	185	struct sama5d2_piobu *piobu;
	186	int ret, i;
	187
	188	piobu = devm_kzalloc(&pdev->dev, sizeof(*piobu), GFP_KERNEL);
	189	if (!piobu)
	190	return -ENOMEM;
	191
	192	platform_set_drvdata(pdev, piobu);
	193	piobu->chip.label = pdev->name;
	194	piobu->chip.parent = &pdev->dev;
	195	piobu->chip.of_node = pdev->dev.of_node;
	196	piobu->chip.owner = THIS_MODULE,
	197	piobu->chip.get_direction = sama5d2_piobu_get_direction,
	198	piobu->chip.direction_input = sama5d2_piobu_direction_input,
	199	piobu->chip.direction_output = sama5d2_piobu_direction_output,
	200	piobu->chip.get = sama5d2_piobu_get,
	201	piobu->chip.set = sama5d2_piobu_set,
	202	piobu->chip.base = -1,
	203	piobu->chip.ngpio = PIOBU_NUM,
	204	piobu->chip.can_sleep = 0,
	205
	206	piobu->regmap = syscon_node_to_regmap(pdev->dev.of_node);
	207	if (IS_ERR(piobu->regmap)) {
	208	dev_err(&pdev->dev, "Failed to get syscon regmap %ld\n",
	209	PTR_ERR(piobu->regmap));
	210	return PTR_ERR(piobu->regmap);
	211	}
	212
	213	ret = devm_gpiochip_add_data(&pdev->dev, &piobu->chip, piobu);
	214	if (ret) {
	215	dev_err(&pdev->dev, "Failed to add gpiochip %d\n", ret);
	216	return ret;
	217	}
	218
	219	for (i = 0; i < PIOBU_NUM; ++i) {
	220	ret = sama5d2_piobu_setup_pin(&piobu->chip, i);
	221	if (ret) {
	222	dev_err(&pdev->dev, "Failed to setup pin: %d %d\n",
	223	i, ret);
	224	return ret;
	225	}
	226	}
	227
	228	return 0;
	229	}
	230
	231	static const struct of_device_id sama5d2_piobu_ids[] = {
	232	{ .compatible = "atmel,sama5d2-secumod" },
	233	{},
234	};
235	MODULE_DEVICE_TABLE(of, sama5d2_piobu_ids);
236
237	static struct platform_driver sama5d2_piobu_driver = {
238	.driver = {
239	.name = "sama5d2-piobu",
240	.of_match_table = of_match_ptr(sama5d2_piobu_ids)
241	},
242	.probe = sama5d2_piobu_probe,
243	};
244
245	module_platform_driver(sama5d2_piobu_driver);
246
fb0b35d3 AS	247	MODULE_LICENSE("GPL v2");
	248	MODULE_DESCRIPTION("SAMA5D2 PIOBU controller driver");
	249	MODULE_AUTHOR("Andrei Stefanescu <[email protected]>");