1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * MEN 16Z127 GPIO driver 4 * 5 * Copyright (C) 2016 MEN Mikroelektronik GmbH (www.men.de) 6 */ 7 8 #include <linux/kernel.h> 9 #include <linux/module.h> 10 #include <linux/io.h> 11 #include <linux/err.h> 12 #include <linux/mcb.h> 13 #include <linux/bitops.h> 14 #include <linux/gpio/driver.h> 15 #include <linux/gpio/generic.h> 16 17 #define MEN_Z127_CTRL 0x00 18 #define MEN_Z127_PSR 0x04 19 #define MEN_Z127_IRQR 0x08 20 #define MEN_Z127_GPIODR 0x0c 21 #define MEN_Z127_IER1 0x10 22 #define MEN_Z127_IER2 0x14 23 #define MEN_Z127_DBER 0x18 24 #define MEN_Z127_ODER 0x1C 25 #define GPIO_TO_DBCNT_REG(gpio) ((gpio * 4) + 0x80) 26 27 #define MEN_Z127_DB_MIN_US 50 28 /* 16 bit compare register. Each bit represents 50us */ 29 #define MEN_Z127_DB_MAX_US (0xffff * MEN_Z127_DB_MIN_US) 30 #define MEN_Z127_DB_IN_RANGE(db) ((db >= MEN_Z127_DB_MIN_US) && \ 31 (db <= MEN_Z127_DB_MAX_US)) 32 33 struct men_z127_gpio { 34 struct gpio_generic_chip chip; 35 void __iomem *reg_base; 36 struct resource *mem; 37 }; 38 39 static int men_z127_debounce(struct gpio_chip *gc, unsigned gpio, 40 unsigned debounce) 41 { 42 struct men_z127_gpio *priv = gpiochip_get_data(gc); 43 struct device *dev = gc->parent; 44 unsigned int rnd; 45 u32 db_en, db_cnt; 46 47 if (!MEN_Z127_DB_IN_RANGE(debounce)) { 48 dev_err(dev, "debounce value %u out of range", debounce); 49 return -EINVAL; 50 } 51 52 if (debounce > 0) { 53 /* round up or down depending on MSB-1 */ 54 rnd = fls(debounce) - 1; 55 56 if (rnd && (debounce & BIT(rnd - 1))) 57 debounce = roundup(debounce, MEN_Z127_DB_MIN_US); 58 else 59 debounce = rounddown(debounce, MEN_Z127_DB_MIN_US); 60 61 if (debounce > MEN_Z127_DB_MAX_US) 62 debounce = MEN_Z127_DB_MAX_US; 63 64 /* 50us per register unit */ 65 debounce /= 50; 66 } 67 68 guard(gpio_generic_lock)(&priv->chip); 69 70 db_en = readl(priv->reg_base + MEN_Z127_DBER); 71 72 if (debounce == 0) { 73 db_en &= ~BIT(gpio); 74 db_cnt = 0; 75 } else { 76 db_en |= BIT(gpio); 77 db_cnt = debounce; 78 } 79 80 writel(db_en, priv->reg_base + MEN_Z127_DBER); 81 writel(db_cnt, priv->reg_base + GPIO_TO_DBCNT_REG(gpio)); 82 83 return 0; 84 } 85 86 static int men_z127_set_single_ended(struct gpio_chip *gc, 87 unsigned offset, 88 enum pin_config_param param) 89 { 90 struct men_z127_gpio *priv = gpiochip_get_data(gc); 91 u32 od_en; 92 93 guard(gpio_generic_lock)(&priv->chip); 94 95 od_en = readl(priv->reg_base + MEN_Z127_ODER); 96 97 if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN) 98 od_en |= BIT(offset); 99 else 100 /* Implicitly PIN_CONFIG_DRIVE_PUSH_PULL */ 101 od_en &= ~BIT(offset); 102 103 writel(od_en, priv->reg_base + MEN_Z127_ODER); 104 105 return 0; 106 } 107 108 static int men_z127_set_config(struct gpio_chip *gc, unsigned offset, 109 unsigned long config) 110 { 111 enum pin_config_param param = pinconf_to_config_param(config); 112 113 switch (param) { 114 case PIN_CONFIG_DRIVE_OPEN_DRAIN: 115 case PIN_CONFIG_DRIVE_PUSH_PULL: 116 return men_z127_set_single_ended(gc, offset, param); 117 118 case PIN_CONFIG_INPUT_DEBOUNCE: 119 return men_z127_debounce(gc, offset, 120 pinconf_to_config_argument(config)); 121 122 default: 123 break; 124 } 125 126 return -ENOTSUPP; 127 } 128 129 static void men_z127_release_mem(void *data) 130 { 131 struct resource *res = data; 132 133 mcb_release_mem(res); 134 } 135 136 static int men_z127_probe(struct mcb_device *mdev, 137 const struct mcb_device_id *id) 138 { 139 struct gpio_generic_chip_config config; 140 struct men_z127_gpio *men_z127_gpio; 141 struct device *dev = &mdev->dev; 142 int ret; 143 144 men_z127_gpio = devm_kzalloc(dev, sizeof(struct men_z127_gpio), 145 GFP_KERNEL); 146 if (!men_z127_gpio) 147 return -ENOMEM; 148 149 men_z127_gpio->mem = mcb_request_mem(mdev, dev_name(dev)); 150 if (IS_ERR(men_z127_gpio->mem)) 151 return dev_err_probe(dev, PTR_ERR(men_z127_gpio->mem), 152 "failed to request device memory"); 153 154 ret = devm_add_action_or_reset(dev, men_z127_release_mem, 155 men_z127_gpio->mem); 156 if (ret) 157 return ret; 158 159 men_z127_gpio->reg_base = devm_ioremap(dev, men_z127_gpio->mem->start, 160 resource_size(men_z127_gpio->mem)); 161 if (men_z127_gpio->reg_base == NULL) 162 return -ENXIO; 163 164 mcb_set_drvdata(mdev, men_z127_gpio); 165 166 config = (struct gpio_generic_chip_config) { 167 .dev = &mdev->dev, 168 .sz = 4, 169 .dat = men_z127_gpio->reg_base + MEN_Z127_PSR, 170 .set = men_z127_gpio->reg_base + MEN_Z127_CTRL, 171 .dirout = men_z127_gpio->reg_base + MEN_Z127_GPIODR, 172 }; 173 174 ret = gpio_generic_chip_init(&men_z127_gpio->chip, &config); 175 if (ret) 176 return ret; 177 178 men_z127_gpio->chip.gc.set_config = men_z127_set_config; 179 180 ret = devm_gpiochip_add_data(dev, &men_z127_gpio->chip.gc, men_z127_gpio); 181 if (ret) 182 return dev_err_probe(dev, ret, 183 "failed to register MEN 16Z127 GPIO controller"); 184 185 return 0; 186 } 187 188 static const struct mcb_device_id men_z127_ids[] = { 189 { .device = 0x7f }, 190 { } 191 }; 192 MODULE_DEVICE_TABLE(mcb, men_z127_ids); 193 194 static struct mcb_driver men_z127_driver = { 195 .driver = { 196 .name = "z127-gpio", 197 }, 198 .probe = men_z127_probe, 199 .id_table = men_z127_ids, 200 }; 201 module_mcb_driver(men_z127_driver); 202 203 MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>"); 204 MODULE_DESCRIPTION("MEN 16z127 GPIO Controller"); 205 MODULE_LICENSE("GPL v2"); 206 MODULE_ALIAS("mcb:16z127"); 207 MODULE_IMPORT_NS("MCB"); 208