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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 | // SPDX-License-Identifier: GPL-2.0 /* * SAMA5D2 PIOBU GPIO controller * * Copyright (C) 2018 Microchip Technology Inc. and its subsidiaries * * Author: Andrei Stefanescu <andrei.stefanescu@microchip.com> * */ #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; piobu->chip.label = pdev->name; piobu->chip.parent = &pdev->dev; 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 = 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 <andrei.stefanescu@microchip.com>"); |