1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * gpiolib support for Wolfson Arizona class devices 4 * 5 * Copyright 2012 Wolfson Microelectronics PLC. 6 * 7 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com> 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/slab.h> 12 #include <linux/module.h> 13 #include <linux/gpio/driver.h> 14 #include <linux/platform_device.h> 15 #include <linux/pm_runtime.h> 16 #include <linux/seq_file.h> 17 18 #include <linux/mfd/arizona/core.h> 19 #include <linux/mfd/arizona/pdata.h> 20 #include <linux/mfd/arizona/registers.h> 21 22 struct arizona_gpio { 23 struct arizona *arizona; 24 struct gpio_chip gpio_chip; 25 }; 26 27 static int arizona_gpio_direction_in(struct gpio_chip *chip, unsigned offset) 28 { 29 struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip); 30 struct arizona *arizona = arizona_gpio->arizona; 31 bool persistent = gpiochip_line_is_persistent(chip, offset); 32 bool change; 33 int ret; 34 35 ret = regmap_update_bits_check(arizona->regmap, 36 ARIZONA_GPIO1_CTRL + offset, 37 ARIZONA_GPN_DIR, ARIZONA_GPN_DIR, 38 &change); 39 if (ret < 0) 40 return ret; 41 42 if (change && persistent) { 43 pm_runtime_mark_last_busy(chip->parent); 44 pm_runtime_put_autosuspend(chip->parent); 45 } 46 47 return 0; 48 } 49 50 static int arizona_gpio_get(struct gpio_chip *chip, unsigned offset) 51 { 52 struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip); 53 struct arizona *arizona = arizona_gpio->arizona; 54 unsigned int reg, val; 55 int ret; 56 57 reg = ARIZONA_GPIO1_CTRL + offset; 58 ret = regmap_read(arizona->regmap, reg, &val); 59 if (ret < 0) 60 return ret; 61 62 /* Resume to read actual registers for input pins */ 63 if (val & ARIZONA_GPN_DIR) { 64 ret = pm_runtime_get_sync(chip->parent); 65 if (ret < 0) { 66 dev_err(chip->parent, "Failed to resume: %d\n", ret); 67 pm_runtime_put_autosuspend(chip->parent); 68 return ret; 69 } 70 71 /* Register is cached, drop it to ensure a physical read */ 72 ret = regcache_drop_region(arizona->regmap, reg, reg); 73 if (ret < 0) { 74 dev_err(chip->parent, "Failed to drop cache: %d\n", 75 ret); 76 pm_runtime_put_autosuspend(chip->parent); 77 return ret; 78 } 79 80 ret = regmap_read(arizona->regmap, reg, &val); 81 if (ret < 0) { 82 pm_runtime_put_autosuspend(chip->parent); 83 return ret; 84 } 85 86 pm_runtime_mark_last_busy(chip->parent); 87 pm_runtime_put_autosuspend(chip->parent); 88 } 89 90 if (val & ARIZONA_GPN_LVL) 91 return 1; 92 else 93 return 0; 94 } 95 96 static int arizona_gpio_direction_out(struct gpio_chip *chip, 97 unsigned offset, int value) 98 { 99 struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip); 100 struct arizona *arizona = arizona_gpio->arizona; 101 bool persistent = gpiochip_line_is_persistent(chip, offset); 102 unsigned int val; 103 int ret; 104 105 ret = regmap_read(arizona->regmap, ARIZONA_GPIO1_CTRL + offset, &val); 106 if (ret < 0) 107 return ret; 108 109 if ((val & ARIZONA_GPN_DIR) && persistent) { 110 ret = pm_runtime_get_sync(chip->parent); 111 if (ret < 0) { 112 dev_err(chip->parent, "Failed to resume: %d\n", ret); 113 pm_runtime_put(chip->parent); 114 return ret; 115 } 116 } 117 118 if (value) 119 value = ARIZONA_GPN_LVL; 120 121 return regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset, 122 ARIZONA_GPN_DIR | ARIZONA_GPN_LVL, value); 123 } 124 125 static void arizona_gpio_set(struct gpio_chip *chip, unsigned offset, int value) 126 { 127 struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip); 128 struct arizona *arizona = arizona_gpio->arizona; 129 130 if (value) 131 value = ARIZONA_GPN_LVL; 132 133 regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset, 134 ARIZONA_GPN_LVL, value); 135 } 136 137 static const struct gpio_chip template_chip = { 138 .label = "arizona", 139 .owner = THIS_MODULE, 140 .direction_input = arizona_gpio_direction_in, 141 .get = arizona_gpio_get, 142 .direction_output = arizona_gpio_direction_out, 143 .set = arizona_gpio_set, 144 .can_sleep = true, 145 }; 146 147 static int arizona_gpio_probe(struct platform_device *pdev) 148 { 149 struct arizona *arizona = dev_get_drvdata(pdev->dev.parent); 150 struct arizona_pdata *pdata = &arizona->pdata; 151 struct arizona_gpio *arizona_gpio; 152 int ret; 153 154 arizona_gpio = devm_kzalloc(&pdev->dev, sizeof(*arizona_gpio), 155 GFP_KERNEL); 156 if (!arizona_gpio) 157 return -ENOMEM; 158 159 arizona_gpio->arizona = arizona; 160 arizona_gpio->gpio_chip = template_chip; 161 arizona_gpio->gpio_chip.parent = &pdev->dev; 162 #ifdef CONFIG_OF_GPIO 163 arizona_gpio->gpio_chip.of_node = arizona->dev->of_node; 164 #endif 165 166 switch (arizona->type) { 167 case WM5102: 168 case WM5110: 169 case WM8280: 170 case WM8997: 171 case WM8998: 172 case WM1814: 173 arizona_gpio->gpio_chip.ngpio = 5; 174 break; 175 case WM1831: 176 case CS47L24: 177 arizona_gpio->gpio_chip.ngpio = 2; 178 break; 179 default: 180 dev_err(&pdev->dev, "Unknown chip variant %d\n", 181 arizona->type); 182 return -EINVAL; 183 } 184 185 if (pdata->gpio_base) 186 arizona_gpio->gpio_chip.base = pdata->gpio_base; 187 else 188 arizona_gpio->gpio_chip.base = -1; 189 190 pm_runtime_enable(&pdev->dev); 191 192 ret = devm_gpiochip_add_data(&pdev->dev, &arizona_gpio->gpio_chip, 193 arizona_gpio); 194 if (ret < 0) { 195 dev_err(&pdev->dev, "Could not register gpiochip, %d\n", 196 ret); 197 return ret; 198 } 199 200 return 0; 201 } 202 203 static struct platform_driver arizona_gpio_driver = { 204 .driver.name = "arizona-gpio", 205 .probe = arizona_gpio_probe, 206 }; 207 208 module_platform_driver(arizona_gpio_driver); 209 210 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); 211 MODULE_DESCRIPTION("GPIO interface for Arizona devices"); 212 MODULE_LICENSE("GPL"); 213 MODULE_ALIAS("platform:arizona-gpio"); 214