1 /* 2 * Generic EP93xx GPIO handling 3 * 4 * Copyright (c) 2008 Ryan Mallon 5 * Copyright (c) 2011 H Hartley Sweeten <hsweeten@visionengravers.com> 6 * 7 * Based on code originally from: 8 * linux/arch/arm/mach-ep93xx/core.c 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License version 2 as 12 * published by the Free Software Foundation. 13 */ 14 15 #include <linux/init.h> 16 #include <linux/module.h> 17 #include <linux/platform_device.h> 18 #include <linux/io.h> 19 #include <linux/gpio.h> 20 #include <linux/irq.h> 21 #include <linux/slab.h> 22 #include <linux/basic_mmio_gpio.h> 23 24 #include <mach/hardware.h> 25 #include <mach/gpio-ep93xx.h> 26 27 #define irq_to_gpio(irq) ((irq) - gpio_to_irq(0)) 28 29 struct ep93xx_gpio { 30 void __iomem *mmio_base; 31 struct bgpio_chip bgc[8]; 32 }; 33 34 /************************************************************************* 35 * Interrupt handling for EP93xx on-chip GPIOs 36 *************************************************************************/ 37 static unsigned char gpio_int_unmasked[3]; 38 static unsigned char gpio_int_enabled[3]; 39 static unsigned char gpio_int_type1[3]; 40 static unsigned char gpio_int_type2[3]; 41 static unsigned char gpio_int_debounce[3]; 42 43 /* Port ordering is: A B F */ 44 static const u8 int_type1_register_offset[3] = { 0x90, 0xac, 0x4c }; 45 static const u8 int_type2_register_offset[3] = { 0x94, 0xb0, 0x50 }; 46 static const u8 eoi_register_offset[3] = { 0x98, 0xb4, 0x54 }; 47 static const u8 int_en_register_offset[3] = { 0x9c, 0xb8, 0x58 }; 48 static const u8 int_debounce_register_offset[3] = { 0xa8, 0xc4, 0x64 }; 49 50 static void ep93xx_gpio_update_int_params(unsigned port) 51 { 52 BUG_ON(port > 2); 53 54 writeb_relaxed(0, EP93XX_GPIO_REG(int_en_register_offset[port])); 55 56 writeb_relaxed(gpio_int_type2[port], 57 EP93XX_GPIO_REG(int_type2_register_offset[port])); 58 59 writeb_relaxed(gpio_int_type1[port], 60 EP93XX_GPIO_REG(int_type1_register_offset[port])); 61 62 writeb(gpio_int_unmasked[port] & gpio_int_enabled[port], 63 EP93XX_GPIO_REG(int_en_register_offset[port])); 64 } 65 66 static void ep93xx_gpio_int_debounce(unsigned int irq, bool enable) 67 { 68 int line = irq_to_gpio(irq); 69 int port = line >> 3; 70 int port_mask = 1 << (line & 7); 71 72 if (enable) 73 gpio_int_debounce[port] |= port_mask; 74 else 75 gpio_int_debounce[port] &= ~port_mask; 76 77 writeb(gpio_int_debounce[port], 78 EP93XX_GPIO_REG(int_debounce_register_offset[port])); 79 } 80 81 static void ep93xx_gpio_ab_irq_handler(unsigned int irq, struct irq_desc *desc) 82 { 83 unsigned char status; 84 int i; 85 86 status = readb(EP93XX_GPIO_A_INT_STATUS); 87 for (i = 0; i < 8; i++) { 88 if (status & (1 << i)) { 89 int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_A(0)) + i; 90 generic_handle_irq(gpio_irq); 91 } 92 } 93 94 status = readb(EP93XX_GPIO_B_INT_STATUS); 95 for (i = 0; i < 8; i++) { 96 if (status & (1 << i)) { 97 int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_B(0)) + i; 98 generic_handle_irq(gpio_irq); 99 } 100 } 101 } 102 103 static void ep93xx_gpio_f_irq_handler(unsigned int irq, struct irq_desc *desc) 104 { 105 /* 106 * map discontiguous hw irq range to continuous sw irq range: 107 * 108 * IRQ_EP93XX_GPIO{0..7}MUX -> gpio_to_irq(EP93XX_GPIO_LINE_F({0..7}) 109 */ 110 int port_f_idx = ((irq + 1) & 7) ^ 4; /* {19..22,47..50} -> {0..7} */ 111 int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_F(0)) + port_f_idx; 112 113 generic_handle_irq(gpio_irq); 114 } 115 116 static void ep93xx_gpio_irq_ack(struct irq_data *d) 117 { 118 int line = irq_to_gpio(d->irq); 119 int port = line >> 3; 120 int port_mask = 1 << (line & 7); 121 122 if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH) { 123 gpio_int_type2[port] ^= port_mask; /* switch edge direction */ 124 ep93xx_gpio_update_int_params(port); 125 } 126 127 writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port])); 128 } 129 130 static void ep93xx_gpio_irq_mask_ack(struct irq_data *d) 131 { 132 int line = irq_to_gpio(d->irq); 133 int port = line >> 3; 134 int port_mask = 1 << (line & 7); 135 136 if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH) 137 gpio_int_type2[port] ^= port_mask; /* switch edge direction */ 138 139 gpio_int_unmasked[port] &= ~port_mask; 140 ep93xx_gpio_update_int_params(port); 141 142 writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port])); 143 } 144 145 static void ep93xx_gpio_irq_mask(struct irq_data *d) 146 { 147 int line = irq_to_gpio(d->irq); 148 int port = line >> 3; 149 150 gpio_int_unmasked[port] &= ~(1 << (line & 7)); 151 ep93xx_gpio_update_int_params(port); 152 } 153 154 static void ep93xx_gpio_irq_unmask(struct irq_data *d) 155 { 156 int line = irq_to_gpio(d->irq); 157 int port = line >> 3; 158 159 gpio_int_unmasked[port] |= 1 << (line & 7); 160 ep93xx_gpio_update_int_params(port); 161 } 162 163 /* 164 * gpio_int_type1 controls whether the interrupt is level (0) or 165 * edge (1) triggered, while gpio_int_type2 controls whether it 166 * triggers on low/falling (0) or high/rising (1). 167 */ 168 static int ep93xx_gpio_irq_type(struct irq_data *d, unsigned int type) 169 { 170 const int gpio = irq_to_gpio(d->irq); 171 const int port = gpio >> 3; 172 const int port_mask = 1 << (gpio & 7); 173 irq_flow_handler_t handler; 174 175 gpio_direction_input(gpio); 176 177 switch (type) { 178 case IRQ_TYPE_EDGE_RISING: 179 gpio_int_type1[port] |= port_mask; 180 gpio_int_type2[port] |= port_mask; 181 handler = handle_edge_irq; 182 break; 183 case IRQ_TYPE_EDGE_FALLING: 184 gpio_int_type1[port] |= port_mask; 185 gpio_int_type2[port] &= ~port_mask; 186 handler = handle_edge_irq; 187 break; 188 case IRQ_TYPE_LEVEL_HIGH: 189 gpio_int_type1[port] &= ~port_mask; 190 gpio_int_type2[port] |= port_mask; 191 handler = handle_level_irq; 192 break; 193 case IRQ_TYPE_LEVEL_LOW: 194 gpio_int_type1[port] &= ~port_mask; 195 gpio_int_type2[port] &= ~port_mask; 196 handler = handle_level_irq; 197 break; 198 case IRQ_TYPE_EDGE_BOTH: 199 gpio_int_type1[port] |= port_mask; 200 /* set initial polarity based on current input level */ 201 if (gpio_get_value(gpio)) 202 gpio_int_type2[port] &= ~port_mask; /* falling */ 203 else 204 gpio_int_type2[port] |= port_mask; /* rising */ 205 handler = handle_edge_irq; 206 break; 207 default: 208 return -EINVAL; 209 } 210 211 __irq_set_handler_locked(d->irq, handler); 212 213 gpio_int_enabled[port] |= port_mask; 214 215 ep93xx_gpio_update_int_params(port); 216 217 return 0; 218 } 219 220 static struct irq_chip ep93xx_gpio_irq_chip = { 221 .name = "GPIO", 222 .irq_ack = ep93xx_gpio_irq_ack, 223 .irq_mask_ack = ep93xx_gpio_irq_mask_ack, 224 .irq_mask = ep93xx_gpio_irq_mask, 225 .irq_unmask = ep93xx_gpio_irq_unmask, 226 .irq_set_type = ep93xx_gpio_irq_type, 227 }; 228 229 static void ep93xx_gpio_init_irq(void) 230 { 231 int gpio_irq; 232 233 for (gpio_irq = gpio_to_irq(0); 234 gpio_irq <= gpio_to_irq(EP93XX_GPIO_LINE_MAX_IRQ); ++gpio_irq) { 235 irq_set_chip_and_handler(gpio_irq, &ep93xx_gpio_irq_chip, 236 handle_level_irq); 237 set_irq_flags(gpio_irq, IRQF_VALID); 238 } 239 240 irq_set_chained_handler(IRQ_EP93XX_GPIO_AB, 241 ep93xx_gpio_ab_irq_handler); 242 irq_set_chained_handler(IRQ_EP93XX_GPIO0MUX, 243 ep93xx_gpio_f_irq_handler); 244 irq_set_chained_handler(IRQ_EP93XX_GPIO1MUX, 245 ep93xx_gpio_f_irq_handler); 246 irq_set_chained_handler(IRQ_EP93XX_GPIO2MUX, 247 ep93xx_gpio_f_irq_handler); 248 irq_set_chained_handler(IRQ_EP93XX_GPIO3MUX, 249 ep93xx_gpio_f_irq_handler); 250 irq_set_chained_handler(IRQ_EP93XX_GPIO4MUX, 251 ep93xx_gpio_f_irq_handler); 252 irq_set_chained_handler(IRQ_EP93XX_GPIO5MUX, 253 ep93xx_gpio_f_irq_handler); 254 irq_set_chained_handler(IRQ_EP93XX_GPIO6MUX, 255 ep93xx_gpio_f_irq_handler); 256 irq_set_chained_handler(IRQ_EP93XX_GPIO7MUX, 257 ep93xx_gpio_f_irq_handler); 258 } 259 260 261 /************************************************************************* 262 * gpiolib interface for EP93xx on-chip GPIOs 263 *************************************************************************/ 264 struct ep93xx_gpio_bank { 265 const char *label; 266 int data; 267 int dir; 268 int base; 269 bool has_debounce; 270 }; 271 272 #define EP93XX_GPIO_BANK(_label, _data, _dir, _base, _debounce) \ 273 { \ 274 .label = _label, \ 275 .data = _data, \ 276 .dir = _dir, \ 277 .base = _base, \ 278 .has_debounce = _debounce, \ 279 } 280 281 static struct ep93xx_gpio_bank ep93xx_gpio_banks[] = { 282 EP93XX_GPIO_BANK("A", 0x00, 0x10, 0, true), 283 EP93XX_GPIO_BANK("B", 0x04, 0x14, 8, true), 284 EP93XX_GPIO_BANK("C", 0x08, 0x18, 40, false), 285 EP93XX_GPIO_BANK("D", 0x0c, 0x1c, 24, false), 286 EP93XX_GPIO_BANK("E", 0x20, 0x24, 32, false), 287 EP93XX_GPIO_BANK("F", 0x30, 0x34, 16, true), 288 EP93XX_GPIO_BANK("G", 0x38, 0x3c, 48, false), 289 EP93XX_GPIO_BANK("H", 0x40, 0x44, 56, false), 290 }; 291 292 static int ep93xx_gpio_set_debounce(struct gpio_chip *chip, 293 unsigned offset, unsigned debounce) 294 { 295 int gpio = chip->base + offset; 296 int irq = gpio_to_irq(gpio); 297 298 if (irq < 0) 299 return -EINVAL; 300 301 ep93xx_gpio_int_debounce(irq, debounce ? true : false); 302 303 return 0; 304 } 305 306 /* 307 * Map GPIO A0..A7 (0..7) to irq 64..71, 308 * B0..B7 (7..15) to irq 72..79, and 309 * F0..F7 (16..24) to irq 80..87. 310 */ 311 static int ep93xx_gpio_to_irq(struct gpio_chip *chip, unsigned offset) 312 { 313 int gpio = chip->base + offset; 314 315 if (gpio > EP93XX_GPIO_LINE_MAX_IRQ) 316 return -EINVAL; 317 318 return 64 + gpio; 319 } 320 321 static int ep93xx_gpio_add_bank(struct bgpio_chip *bgc, struct device *dev, 322 void __iomem *mmio_base, struct ep93xx_gpio_bank *bank) 323 { 324 void __iomem *data = mmio_base + bank->data; 325 void __iomem *dir = mmio_base + bank->dir; 326 int err; 327 328 err = bgpio_init(bgc, dev, 1, data, NULL, NULL, dir, NULL, 0); 329 if (err) 330 return err; 331 332 bgc->gc.label = bank->label; 333 bgc->gc.base = bank->base; 334 335 if (bank->has_debounce) { 336 bgc->gc.set_debounce = ep93xx_gpio_set_debounce; 337 bgc->gc.to_irq = ep93xx_gpio_to_irq; 338 } 339 340 return gpiochip_add(&bgc->gc); 341 } 342 343 static int ep93xx_gpio_probe(struct platform_device *pdev) 344 { 345 struct ep93xx_gpio *ep93xx_gpio; 346 struct resource *res; 347 int i; 348 struct device *dev = &pdev->dev; 349 350 ep93xx_gpio = devm_kzalloc(dev, sizeof(struct ep93xx_gpio), GFP_KERNEL); 351 if (!ep93xx_gpio) 352 return -ENOMEM; 353 354 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 355 ep93xx_gpio->mmio_base = devm_ioremap_resource(dev, res); 356 if (IS_ERR(ep93xx_gpio->mmio_base)) 357 return PTR_ERR(ep93xx_gpio->mmio_base); 358 359 for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) { 360 struct bgpio_chip *bgc = &ep93xx_gpio->bgc[i]; 361 struct ep93xx_gpio_bank *bank = &ep93xx_gpio_banks[i]; 362 363 if (ep93xx_gpio_add_bank(bgc, &pdev->dev, 364 ep93xx_gpio->mmio_base, bank)) 365 dev_warn(&pdev->dev, "Unable to add gpio bank %s\n", 366 bank->label); 367 } 368 369 ep93xx_gpio_init_irq(); 370 371 return 0; 372 } 373 374 static struct platform_driver ep93xx_gpio_driver = { 375 .driver = { 376 .name = "gpio-ep93xx", 377 .owner = THIS_MODULE, 378 }, 379 .probe = ep93xx_gpio_probe, 380 }; 381 382 static int __init ep93xx_gpio_init(void) 383 { 384 return platform_driver_register(&ep93xx_gpio_driver); 385 } 386 postcore_initcall(ep93xx_gpio_init); 387 388 MODULE_AUTHOR("Ryan Mallon <ryan@bluewatersys.com> " 389 "H Hartley Sweeten <hsweeten@visionengravers.com>"); 390 MODULE_DESCRIPTION("EP93XX GPIO driver"); 391 MODULE_LICENSE("GPL"); 392