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 16 #define MEN_Z127_CTRL 0x00 17 #define MEN_Z127_PSR 0x04 18 #define MEN_Z127_IRQR 0x08 19 #define MEN_Z127_GPIODR 0x0c 20 #define MEN_Z127_IER1 0x10 21 #define MEN_Z127_IER2 0x14 22 #define MEN_Z127_DBER 0x18 23 #define MEN_Z127_ODER 0x1C 24 #define GPIO_TO_DBCNT_REG(gpio) ((gpio * 4) + 0x80) 25 26 #define MEN_Z127_DB_MIN_US 50 27 /* 16 bit compare register. Each bit represents 50us */ 28 #define MEN_Z127_DB_MAX_US (0xffff * MEN_Z127_DB_MIN_US) 29 #define MEN_Z127_DB_IN_RANGE(db) ((db >= MEN_Z127_DB_MIN_US) && \ 30 (db <= MEN_Z127_DB_MAX_US)) 31 32 struct men_z127_gpio { 33 struct gpio_chip gc; 34 void __iomem *reg_base; 35 struct resource *mem; 36 }; 37 38 static int men_z127_debounce(struct gpio_chip *gc, unsigned gpio, 39 unsigned debounce) 40 { 41 struct men_z127_gpio *priv = gpiochip_get_data(gc); 42 struct device *dev = gc->parent; 43 unsigned int rnd; 44 u32 db_en, db_cnt; 45 46 if (!MEN_Z127_DB_IN_RANGE(debounce)) { 47 dev_err(dev, "debounce value %u out of range", debounce); 48 return -EINVAL; 49 } 50 51 if (debounce > 0) { 52 /* round up or down depending on MSB-1 */ 53 rnd = fls(debounce) - 1; 54 55 if (rnd && (debounce & BIT(rnd - 1))) 56 debounce = roundup(debounce, MEN_Z127_DB_MIN_US); 57 else 58 debounce = rounddown(debounce, MEN_Z127_DB_MIN_US); 59 60 if (debounce > MEN_Z127_DB_MAX_US) 61 debounce = MEN_Z127_DB_MAX_US; 62 63 /* 50us per register unit */ 64 debounce /= 50; 65 } 66 67 spin_lock(&gc->bgpio_lock); 68 69 db_en = readl(priv->reg_base + MEN_Z127_DBER); 70 71 if (debounce == 0) { 72 db_en &= ~BIT(gpio); 73 db_cnt = 0; 74 } else { 75 db_en |= BIT(gpio); 76 db_cnt = debounce; 77 } 78 79 writel(db_en, priv->reg_base + MEN_Z127_DBER); 80 writel(db_cnt, priv->reg_base + GPIO_TO_DBCNT_REG(gpio)); 81 82 spin_unlock(&gc->bgpio_lock); 83 84 return 0; 85 } 86 87 static int men_z127_set_single_ended(struct gpio_chip *gc, 88 unsigned offset, 89 enum pin_config_param param) 90 { 91 struct men_z127_gpio *priv = gpiochip_get_data(gc); 92 u32 od_en; 93 94 spin_lock(&gc->bgpio_lock); 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 spin_unlock(&gc->bgpio_lock); 105 106 return 0; 107 } 108 109 static int men_z127_set_config(struct gpio_chip *gc, unsigned offset, 110 unsigned long config) 111 { 112 enum pin_config_param param = pinconf_to_config_param(config); 113 114 switch (param) { 115 case PIN_CONFIG_DRIVE_OPEN_DRAIN: 116 case PIN_CONFIG_DRIVE_PUSH_PULL: 117 return men_z127_set_single_ended(gc, offset, param); 118 119 case PIN_CONFIG_INPUT_DEBOUNCE: 120 return men_z127_debounce(gc, offset, 121 pinconf_to_config_argument(config)); 122 123 default: 124 break; 125 } 126 127 return -ENOTSUPP; 128 } 129 130 static int men_z127_probe(struct mcb_device *mdev, 131 const struct mcb_device_id *id) 132 { 133 struct men_z127_gpio *men_z127_gpio; 134 struct device *dev = &mdev->dev; 135 int ret; 136 137 men_z127_gpio = devm_kzalloc(dev, sizeof(struct men_z127_gpio), 138 GFP_KERNEL); 139 if (!men_z127_gpio) 140 return -ENOMEM; 141 142 men_z127_gpio->mem = mcb_request_mem(mdev, dev_name(dev)); 143 if (IS_ERR(men_z127_gpio->mem)) { 144 dev_err(dev, "failed to request device memory"); 145 return PTR_ERR(men_z127_gpio->mem); 146 } 147 148 men_z127_gpio->reg_base = ioremap(men_z127_gpio->mem->start, 149 resource_size(men_z127_gpio->mem)); 150 if (men_z127_gpio->reg_base == NULL) { 151 ret = -ENXIO; 152 goto err_release; 153 } 154 155 mcb_set_drvdata(mdev, men_z127_gpio); 156 157 ret = bgpio_init(&men_z127_gpio->gc, &mdev->dev, 4, 158 men_z127_gpio->reg_base + MEN_Z127_PSR, 159 men_z127_gpio->reg_base + MEN_Z127_CTRL, 160 NULL, 161 men_z127_gpio->reg_base + MEN_Z127_GPIODR, 162 NULL, 0); 163 if (ret) 164 goto err_unmap; 165 166 men_z127_gpio->gc.set_config = men_z127_set_config; 167 168 ret = gpiochip_add_data(&men_z127_gpio->gc, men_z127_gpio); 169 if (ret) { 170 dev_err(dev, "failed to register MEN 16Z127 GPIO controller"); 171 goto err_unmap; 172 } 173 174 dev_info(dev, "MEN 16Z127 GPIO driver registered"); 175 176 return 0; 177 178 err_unmap: 179 iounmap(men_z127_gpio->reg_base); 180 err_release: 181 mcb_release_mem(men_z127_gpio->mem); 182 return ret; 183 } 184 185 static void men_z127_remove(struct mcb_device *mdev) 186 { 187 struct men_z127_gpio *men_z127_gpio = mcb_get_drvdata(mdev); 188 189 gpiochip_remove(&men_z127_gpio->gc); 190 iounmap(men_z127_gpio->reg_base); 191 mcb_release_mem(men_z127_gpio->mem); 192 } 193 194 static const struct mcb_device_id men_z127_ids[] = { 195 { .device = 0x7f }, 196 { } 197 }; 198 MODULE_DEVICE_TABLE(mcb, men_z127_ids); 199 200 static struct mcb_driver men_z127_driver = { 201 .driver = { 202 .name = "z127-gpio", 203 }, 204 .probe = men_z127_probe, 205 .remove = men_z127_remove, 206 .id_table = men_z127_ids, 207 }; 208 module_mcb_driver(men_z127_driver); 209 210 MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>"); 211 MODULE_DESCRIPTION("MEN 16z127 GPIO Controller"); 212 MODULE_LICENSE("GPL v2"); 213 MODULE_ALIAS("mcb:16z127"); 214