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 /* MEN Z127 supported model ids*/ 28 #define MEN_Z127_ID 0x7f 29 #define MEN_Z034_ID 0x22 30 #define MEN_Z037_ID 0x25 31 32 #define MEN_Z127_DB_MIN_US 50 33 /* 16 bit compare register. Each bit represents 50us */ 34 #define MEN_Z127_DB_MAX_US (0xffff * MEN_Z127_DB_MIN_US) 35 #define MEN_Z127_DB_IN_RANGE(db) ((db >= MEN_Z127_DB_MIN_US) && \ 36 (db <= MEN_Z127_DB_MAX_US)) 37 38 struct men_z127_gpio { 39 struct gpio_generic_chip chip; 40 void __iomem *reg_base; 41 struct resource *mem; 42 }; 43 44 static int men_z127_debounce(struct gpio_chip *gc, unsigned gpio, 45 unsigned debounce) 46 { 47 struct men_z127_gpio *priv = gpiochip_get_data(gc); 48 struct device *dev = gc->parent; 49 unsigned int rnd; 50 u32 db_en, db_cnt; 51 52 if (!MEN_Z127_DB_IN_RANGE(debounce)) { 53 dev_err(dev, "debounce value %u out of range", debounce); 54 return -EINVAL; 55 } 56 57 if (debounce > 0) { 58 /* round up or down depending on MSB-1 */ 59 rnd = fls(debounce) - 1; 60 61 if (rnd && (debounce & BIT(rnd - 1))) 62 debounce = roundup(debounce, MEN_Z127_DB_MIN_US); 63 else 64 debounce = rounddown(debounce, MEN_Z127_DB_MIN_US); 65 66 if (debounce > MEN_Z127_DB_MAX_US) 67 debounce = MEN_Z127_DB_MAX_US; 68 69 /* 50us per register unit */ 70 debounce /= 50; 71 } 72 73 guard(gpio_generic_lock)(&priv->chip); 74 75 db_en = readl(priv->reg_base + MEN_Z127_DBER); 76 77 if (debounce == 0) { 78 db_en &= ~BIT(gpio); 79 db_cnt = 0; 80 } else { 81 db_en |= BIT(gpio); 82 db_cnt = debounce; 83 } 84 85 writel(db_en, priv->reg_base + MEN_Z127_DBER); 86 writel(db_cnt, priv->reg_base + GPIO_TO_DBCNT_REG(gpio)); 87 88 return 0; 89 } 90 91 static int men_z127_set_single_ended(struct gpio_chip *gc, 92 unsigned offset, 93 enum pin_config_param param) 94 { 95 struct men_z127_gpio *priv = gpiochip_get_data(gc); 96 u32 od_en; 97 98 guard(gpio_generic_lock)(&priv->chip); 99 100 od_en = readl(priv->reg_base + MEN_Z127_ODER); 101 102 if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN) 103 od_en |= BIT(offset); 104 else 105 /* Implicitly PIN_CONFIG_DRIVE_PUSH_PULL */ 106 od_en &= ~BIT(offset); 107 108 writel(od_en, priv->reg_base + MEN_Z127_ODER); 109 110 return 0; 111 } 112 113 static int men_z127_set_config(struct gpio_chip *gc, unsigned offset, 114 unsigned long config) 115 { 116 enum pin_config_param param = pinconf_to_config_param(config); 117 118 switch (param) { 119 case PIN_CONFIG_DRIVE_OPEN_DRAIN: 120 case PIN_CONFIG_DRIVE_PUSH_PULL: 121 return men_z127_set_single_ended(gc, offset, param); 122 123 case PIN_CONFIG_INPUT_DEBOUNCE: 124 return men_z127_debounce(gc, offset, 125 pinconf_to_config_argument(config)); 126 127 default: 128 break; 129 } 130 131 return -ENOTSUPP; 132 } 133 134 static void men_z127_release_mem(void *data) 135 { 136 struct resource *res = data; 137 138 mcb_release_mem(res); 139 } 140 141 static int men_z127_probe(struct mcb_device *mdev, 142 const struct mcb_device_id *id) 143 { 144 struct gpio_generic_chip_config config; 145 struct men_z127_gpio *men_z127_gpio; 146 struct device *dev = &mdev->dev; 147 int ret; 148 unsigned long sz; 149 150 men_z127_gpio = devm_kzalloc(dev, sizeof(struct men_z127_gpio), 151 GFP_KERNEL); 152 if (!men_z127_gpio) 153 return -ENOMEM; 154 155 men_z127_gpio->mem = mcb_request_mem(mdev, dev_name(dev)); 156 if (IS_ERR(men_z127_gpio->mem)) 157 return dev_err_probe(dev, PTR_ERR(men_z127_gpio->mem), 158 "failed to request device memory"); 159 160 ret = devm_add_action_or_reset(dev, men_z127_release_mem, 161 men_z127_gpio->mem); 162 if (ret) 163 return ret; 164 165 men_z127_gpio->reg_base = devm_ioremap(dev, men_z127_gpio->mem->start, 166 resource_size(men_z127_gpio->mem)); 167 if (men_z127_gpio->reg_base == NULL) 168 return -ENXIO; 169 170 mcb_set_drvdata(mdev, men_z127_gpio); 171 172 switch (mdev->id) { 173 case MEN_Z127_ID: 174 sz = 4; 175 break; 176 case MEN_Z034_ID: 177 case MEN_Z037_ID: 178 sz = 1; 179 break; 180 default: 181 return dev_err_probe(&mdev->dev, -EINVAL, "no size found for id %d", mdev->id); 182 } 183 184 config = (struct gpio_generic_chip_config) { 185 .dev = &mdev->dev, 186 .sz = sz, 187 .dat = men_z127_gpio->reg_base + MEN_Z127_PSR, 188 .set = men_z127_gpio->reg_base + MEN_Z127_CTRL, 189 .dirout = men_z127_gpio->reg_base + MEN_Z127_GPIODR, 190 }; 191 192 ret = gpio_generic_chip_init(&men_z127_gpio->chip, &config); 193 if (ret) 194 return ret; 195 196 men_z127_gpio->chip.gc.set_config = men_z127_set_config; 197 198 ret = devm_gpiochip_add_data(dev, &men_z127_gpio->chip.gc, men_z127_gpio); 199 if (ret) 200 return dev_err_probe(dev, ret, 201 "failed to register MEN 16Z127 GPIO controller"); 202 203 return 0; 204 } 205 206 static const struct mcb_device_id men_z127_ids[] = { 207 { .device = MEN_Z127_ID }, 208 { .device = MEN_Z034_ID }, 209 { .device = MEN_Z037_ID }, 210 { } 211 }; 212 MODULE_DEVICE_TABLE(mcb, men_z127_ids); 213 214 static struct mcb_driver men_z127_driver = { 215 .driver = { 216 .name = "z127-gpio", 217 }, 218 .probe = men_z127_probe, 219 .id_table = men_z127_ids, 220 }; 221 module_mcb_driver(men_z127_driver); 222 223 MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>"); 224 MODULE_DESCRIPTION("MEN GPIO Controller"); 225 MODULE_LICENSE("GPL v2"); 226 MODULE_ALIAS("mcb:16z127"); 227 MODULE_IMPORT_NS("MCB"); 228