drivers/gpio/gpio-ep93xx.c

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