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1// SPDX-License-Identifier: GPL-2.02/*3 * SAMA5D2 PIOBU GPIO controller4 *5 * Copyright (C) 2018 Microchip Technology Inc. and its subsidiaries6 *7 * Author: Andrei Stefanescu <andrei.stefanescu@microchip.com>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 821#define PIOBU_REG_SIZE 422 23/*24 * backup mode protection register for tamper detection25 * normal mode protection register for tamper detection26 * wakeup signal generation27 */28#define PIOBU_BMPR 0x7C29#define PIOBU_NMPR 0x8030#define PIOBU_WKPR 0x9031 32#define PIOBU_BASE 0x18 /* PIOBU offset from SECUMOD base register address. */33 34#define PIOBU_DET_OFFSET 1635 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 040 41#define PIOBU_SOD BIT(9)42#define PIOBU_PDS BIT(10)43 44#define PIOBU_HIGH BIT(9)45#define PIOBU_LOW 046 47struct sama5d2_piobu {48 struct gpio_chip chip;49 struct regmap *regmap;50};51 52/*53 * sama5d2_piobu_setup_pin() - prepares a pin for set_direction call54 *55 * Do not consider pin for tamper detection (normal and backup modes)56 * Do not consider pin as tamper wakeup interrupt source57 */58static 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 76/*77 * sama5d2_piobu_write_value() - writes value & mask at the pin's PIOBU register78 */79static 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 91/*92 * sama5d2_piobu_read_value() - read the value with masking from the pin's PIOBU93 * register94 */95static 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}110 111/*112 * sama5d2_piobu_get_direction() - gpiochip get_direction113 */114static 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;121 122 return (ret == PIOBU_IN) ? GPIO_LINE_DIRECTION_IN :123 GPIO_LINE_DIRECTION_OUT;124}125 126/*127 * sama5d2_piobu_direction_input() - gpiochip direction_input128 */129static int sama5d2_piobu_direction_input(struct gpio_chip *chip,130 unsigned int pin)131{132 return sama5d2_piobu_write_value(chip, pin, PIOBU_DIRECTION, PIOBU_IN);133}134 135/*136 * sama5d2_piobu_direction_output() - gpiochip direction_output137 */138static int sama5d2_piobu_direction_output(struct gpio_chip *chip,139 unsigned int pin, int value)140{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);148}149 150/*151 * sama5d2_piobu_get() - gpiochip get152 */153static 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);157 158 if (ret == GPIO_LINE_DIRECTION_IN)159 ret = sama5d2_piobu_read_value(chip, pin, PIOBU_PDS);160 else if (ret == GPIO_LINE_DIRECTION_OUT)161 ret = sama5d2_piobu_read_value(chip, pin, PIOBU_SOD);162 163 if (ret < 0)164 return ret;165 166 return !!ret;167}168 169/*170 * sama5d2_piobu_set() - gpiochip set171 */172static void sama5d2_piobu_set(struct gpio_chip *chip, unsigned int pin,173 int value)174{175 if (!value)176 value = PIOBU_LOW;177 else178 value = PIOBU_HIGH;179 180 sama5d2_piobu_write_value(chip, pin, PIOBU_SOD, value);181}182 183static 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 piobu->chip.label = pdev->name;193 piobu->chip.parent = &pdev->dev;194 piobu->chip.owner = THIS_MODULE;195 piobu->chip.get_direction = sama5d2_piobu_get_direction;196 piobu->chip.direction_input = sama5d2_piobu_direction_input;197 piobu->chip.direction_output = sama5d2_piobu_direction_output;198 piobu->chip.get = sama5d2_piobu_get;199 piobu->chip.set = sama5d2_piobu_set;200 piobu->chip.base = -1;201 piobu->chip.ngpio = PIOBU_NUM;202 piobu->chip.can_sleep = 0;203 204 piobu->regmap = syscon_node_to_regmap(pdev->dev.of_node);205 if (IS_ERR(piobu->regmap)) {206 dev_err(&pdev->dev, "Failed to get syscon regmap %ld\n",207 PTR_ERR(piobu->regmap));208 return PTR_ERR(piobu->regmap);209 }210 211 ret = devm_gpiochip_add_data(&pdev->dev, &piobu->chip, piobu);212 if (ret) {213 dev_err(&pdev->dev, "Failed to add gpiochip %d\n", ret);214 return ret;215 }216 217 for (i = 0; i < PIOBU_NUM; ++i) {218 ret = sama5d2_piobu_setup_pin(&piobu->chip, i);219 if (ret) {220 dev_err(&pdev->dev, "Failed to setup pin: %d %d\n",221 i, ret);222 return ret;223 }224 }225 226 return 0;227}228 229static const struct of_device_id sama5d2_piobu_ids[] = {230 { .compatible = "atmel,sama5d2-secumod" },231 {},232};233MODULE_DEVICE_TABLE(of, sama5d2_piobu_ids);234 235static struct platform_driver sama5d2_piobu_driver = {236 .driver = {237 .name = "sama5d2-piobu",238 .of_match_table = sama5d2_piobu_ids,239 },240 .probe = sama5d2_piobu_probe,241};242 243module_platform_driver(sama5d2_piobu_driver);244 245MODULE_LICENSE("GPL v2");246MODULE_DESCRIPTION("SAMA5D2 PIOBU controller driver");247MODULE_AUTHOR("Andrei Stefanescu <andrei.stefanescu@microchip.com>");248