arch/arm/mach-davinci/gpio.c

   1 /*
   2  * TI DaVinci GPIO Support
   3  *
   4  * Copyright (c) 2006-2007 David Brownell
   5  * Copyright (c) 2007, MontaVista Software, Inc. <source@mvista.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  */
  12
  13 #include <linux/errno.h>
  14 #include <linux/kernel.h>
  15 #include <linux/clk.h>
  16 #include <linux/err.h>
  17 #include <linux/io.h>
  18
  19 #include <mach/gpio.h>
  20
  21 #include <asm/mach/irq.h>
  22
  23 struct davinci_gpio_regs {
  24         u32     dir;
  25         u32     out_data;
  26         u32     set_data;
  27         u32     clr_data;
  28         u32     in_data;
  29         u32     set_rising;
  30         u32     clr_rising;
  31         u32     set_falling;
  32         u32     clr_falling;
  33         u32     intstat;
  34 };
  35
  36 #define chip2controller(chip)   \
  37         container_of(chip, struct davinci_gpio_controller, chip)
  38
  39 static struct davinci_gpio_controller chips[DIV_ROUND_UP(DAVINCI_N_GPIO, 32)];
  40
  41 static struct davinci_gpio_regs __iomem __init *gpio2regs(unsigned gpio)
  42 {
  43         void __iomem *ptr;
  44         void __iomem *base = davinci_soc_info.gpio_base;
  45
  46         if (gpio < 32 * 1)
  47                 ptr = base + 0x10;
  48         else if (gpio < 32 * 2)
  49                 ptr = base + 0x38;
  50         else if (gpio < 32 * 3)
  51                 ptr = base + 0x60;
  52         else if (gpio < 32 * 4)
  53                 ptr = base + 0x88;
  54         else if (gpio < 32 * 5)
  55                 ptr = base + 0xb0;
  56         else
  57                 ptr = NULL;
  58         return ptr;
  59 }
  60
  61 static inline struct davinci_gpio_regs __iomem *irq2regs(int irq)
  62 {
  63         struct davinci_gpio_regs __iomem *g;
  64
  65         g = (__force struct davinci_gpio_regs __iomem *)get_irq_chip_data(irq);
  66
  67         return g;
  68 }
  69
  70 static int __init davinci_gpio_irq_setup(void);
  71
  72 /*--------------------------------------------------------------------------*/
  73
  74 /* board setup code *MUST* setup pinmux and enable the GPIO clock. */
  75 static inline int __davinci_direction(struct gpio_chip *chip,
  76                         unsigned offset, bool out, int value)
  77 {
  78         struct davinci_gpio_controller *d = chip2controller(chip);
  79         struct davinci_gpio_regs __iomem *g = d->regs;
  80         unsigned long flags;
  81         u32 temp;
  82         u32 mask = 1 << offset;
  83
  84         spin_lock_irqsave(&d->lock, flags);
  85         temp = __raw_readl(&g->dir);
  86         if (out) {
  87                 temp &= ~mask;
  88                 __raw_writel(mask, value ? &g->set_data : &g->clr_data);
  89         } else {
  90                 temp |= mask;
  91         }
  92         __raw_writel(temp, &g->dir);
  93         spin_unlock_irqrestore(&d->lock, flags);
  94
  95         return 0;
  96 }
  97
  98 static int davinci_direction_in(struct gpio_chip *chip, unsigned offset)
  99 {
 100         return __davinci_direction(chip, offset, false, 0);
 101 }
 102
 103 static int
 104 davinci_direction_out(struct gpio_chip *chip, unsigned offset, int value)
 105 {
 106         return __davinci_direction(chip, offset, true, value);
 107 }
 108
 109 /*
 110  * Read the pin's value (works even if it's set up as output);
 111  * returns zero/nonzero.
 112  *
 113  * Note that changes are synched to the GPIO clock, so reading values back
 114  * right after you've set them may give old values.
 115  */
 116 static int davinci_gpio_get(struct gpio_chip *chip, unsigned offset)
 117 {
 118         struct davinci_gpio_controller *d = chip2controller(chip);
 119         struct davinci_gpio_regs __iomem *g = d->regs;
 120
 121         return (1 << offset) & __raw_readl(&g->in_data);
 122 }
 123
 124 /*
 125  * Assuming the pin is muxed as a gpio output, set its output value.
 126  */
 127 static void
 128 davinci_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 129 {
 130         struct davinci_gpio_controller *d = chip2controller(chip);
 131         struct davinci_gpio_regs __iomem *g = d->regs;
 132
 133         __raw_writel((1 << offset), value ? &g->set_data : &g->clr_data);
 134 }
 135
 136 static int __init davinci_gpio_setup(void)
 137 {
 138         int i, base;
 139         unsigned ngpio;
 140         struct davinci_soc_info *soc_info = &davinci_soc_info;
 141         struct davinci_gpio_regs *regs;
 142
 143         if (soc_info->gpio_type != GPIO_TYPE_DAVINCI)
 144                 return 0;
 145
 146         /*
 147          * The gpio banks conceptually expose a segmented bitmap,
 148          * and "ngpio" is one more than the largest zero-based
 149          * bit index that's valid.
 150          */
 151         ngpio = soc_info->gpio_num;
 152         if (ngpio == 0) {
 153                 pr_err("GPIO setup:  how many GPIOs?\n");
 154                 return -EINVAL;
 155         }
 156
 157         if (WARN_ON(DAVINCI_N_GPIO < ngpio))
 158                 ngpio = DAVINCI_N_GPIO;
 159
 160         for (i = 0, base = 0; base < ngpio; i++, base += 32) {
 161                 chips[i].chip.label = "DaVinci";
 162
 163                 chips[i].chip.direction_input = davinci_direction_in;
 164                 chips[i].chip.get = davinci_gpio_get;
 165                 chips[i].chip.direction_output = davinci_direction_out;
 166                 chips[i].chip.set = davinci_gpio_set;
 167
 168                 chips[i].chip.base = base;
 169                 chips[i].chip.ngpio = ngpio - base;
 170                 if (chips[i].chip.ngpio > 32)
 171                         chips[i].chip.ngpio = 32;
 172
 173                 spin_lock_init(&chips[i].lock);
 174
 175                 regs = gpio2regs(base);
 176                 chips[i].regs = regs;
 177                 chips[i].set_data = &regs->set_data;
 178                 chips[i].clr_data = &regs->clr_data;
 179                 chips[i].in_data = &regs->in_data;
 180
 181                 gpiochip_add(&chips[i].chip);
 182         }
 183
 184         soc_info->gpio_ctlrs = chips;
 185         soc_info->gpio_ctlrs_num = DIV_ROUND_UP(ngpio, 32);
 186
 187         davinci_gpio_irq_setup();
 188         return 0;
 189 }
 190 pure_initcall(davinci_gpio_setup);
 191
 192 /*--------------------------------------------------------------------------*/
 193 /*
 194  * We expect irqs will normally be set up as input pins, but they can also be
 195  * used as output pins ... which is convenient for testing.
 196  *
 197  * NOTE:  The first few GPIOs also have direct INTC hookups in addition
 198  * to their GPIOBNK0 irq, with a bit less overhead.
 199  *
 200  * All those INTC hookups (direct, plus several IRQ banks) can also
 201  * serve as EDMA event triggers.
 202  */
 203
 204 static void gpio_irq_disable(unsigned irq)
 205 {
 206         struct davinci_gpio_regs __iomem *g = irq2regs(irq);
 207         u32 mask = (u32) get_irq_data(irq);
 208
 209         __raw_writel(mask, &g->clr_falling);
 210         __raw_writel(mask, &g->clr_rising);
 211 }
 212
 213 static void gpio_irq_enable(unsigned irq)
 214 {
 215         struct davinci_gpio_regs __iomem *g = irq2regs(irq);
 216         u32 mask = (u32) get_irq_data(irq);
 217         unsigned status = irq_desc[irq].status;
 218
 219         status &= IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;
 220         if (!status)
 221                 status = IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;
 222
 223         if (status & IRQ_TYPE_EDGE_FALLING)
 224                 __raw_writel(mask, &g->set_falling);
 225         if (status & IRQ_TYPE_EDGE_RISING)
 226                 __raw_writel(mask, &g->set_rising);
 227 }
 228
 229 static int gpio_irq_type(unsigned irq, unsigned trigger)
 230 {
 231         struct davinci_gpio_regs __iomem *g = irq2regs(irq);
 232         u32 mask = (u32) get_irq_data(irq);
 233
 234         if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
 235                 return -EINVAL;
 236
 237         irq_desc[irq].status &= ~IRQ_TYPE_SENSE_MASK;
 238         irq_desc[irq].status |= trigger;
 239
 240         /* don't enable the IRQ if it's currently disabled */
 241         if (irq_desc[irq].depth == 0) {
 242                 __raw_writel(mask, (trigger & IRQ_TYPE_EDGE_FALLING)
 243                              ? &g->set_falling : &g->clr_falling);
 244                 __raw_writel(mask, (trigger & IRQ_TYPE_EDGE_RISING)
 245                              ? &g->set_rising : &g->clr_rising);
 246         }
 247         return 0;
 248 }
 249
 250 static struct irq_chip gpio_irqchip = {
 251         .name           = "GPIO",
 252         .enable         = gpio_irq_enable,
 253         .disable        = gpio_irq_disable,
 254         .set_type       = gpio_irq_type,
 255 };
 256
 257 static void
 258 gpio_irq_handler(unsigned irq, struct irq_desc *desc)
 259 {
 260         struct davinci_gpio_regs __iomem *g = irq2regs(irq);
 261         u32 mask = 0xffff;
 262
 263         /* we only care about one bank */
 264         if (irq & 1)
 265                 mask <<= 16;
 266
 267         /* temporarily mask (level sensitive) parent IRQ */
 268         desc->chip->mask(irq);
 269         desc->chip->ack(irq);
 270         while (1) {
 271                 u32             status;
 272                 int             n;
 273                 int             res;
 274
 275                 /* ack any irqs */
 276                 status = __raw_readl(&g->intstat) & mask;
 277                 if (!status)
 278                         break;
 279                 __raw_writel(status, &g->intstat);
 280                 if (irq & 1)
 281                         status >>= 16;
 282
 283                 /* now demux them to the right lowlevel handler */
 284                 n = (int)get_irq_data(irq);
 285                 while (status) {
 286                         res = ffs(status);
 287                         n += res;
 288                         generic_handle_irq(n - 1);
 289                         status >>= res;
 290                 }
 291         }
 292         desc->chip->unmask(irq);
 293         /* now it may re-trigger */
 294 }
 295
 296 static int gpio_to_irq_banked(struct gpio_chip *chip, unsigned offset)
 297 {
 298         struct davinci_gpio_controller *d = chip2controller(chip);
 299
 300         if (d->irq_base >= 0)
 301                 return d->irq_base + offset;
 302         else
 303                 return -ENODEV;
 304 }
 305
 306 static int gpio_to_irq_unbanked(struct gpio_chip *chip, unsigned offset)
 307 {
 308         struct davinci_soc_info *soc_info = &davinci_soc_info;
 309
 310         /* NOTE:  we assume for now that only irqs in the first gpio_chip
 311          * can provide direct-mapped IRQs to AINTC (up to 32 GPIOs).
 312          */
 313         if (offset < soc_info->gpio_unbanked)
 314                 return soc_info->gpio_irq + offset;
 315         else
 316                 return -ENODEV;
 317 }
 318
 319 static int gpio_irq_type_unbanked(unsigned irq, unsigned trigger)
 320 {
 321         struct davinci_gpio_regs __iomem *g = irq2regs(irq);
 322         u32 mask = (u32) get_irq_data(irq);
 323
 324         if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
 325                 return -EINVAL;
 326
 327         __raw_writel(mask, (trigger & IRQ_TYPE_EDGE_FALLING)
 328                      ? &g->set_falling : &g->clr_falling);
 329         __raw_writel(mask, (trigger & IRQ_TYPE_EDGE_RISING)
 330                      ? &g->set_rising : &g->clr_rising);
 331
 332         return 0;
 333 }
 334
 335 /*
 336  * NOTE:  for suspend/resume, probably best to make a platform_device with
 337  * suspend_late/resume_resume calls hooking into results of the set_wake()
 338  * calls ... so if no gpios are wakeup events the clock can be disabled,
 339  * with outputs left at previously set levels, and so that VDD3P3V.IOPWDN0
 340  * (dm6446) can be set appropriately for GPIOV33 pins.
 341  */
 342
 343 static int __init davinci_gpio_irq_setup(void)
 344 {
 345         unsigned        gpio, irq, bank;
 346         struct clk      *clk;
 347         u32             binten = 0;
 348         unsigned        ngpio, bank_irq;
 349         struct davinci_soc_info *soc_info = &davinci_soc_info;
 350         struct davinci_gpio_regs        __iomem *g;
 351
 352         ngpio = soc_info->gpio_num;
 353
 354         bank_irq = soc_info->gpio_irq;
 355         if (bank_irq == 0) {
 356                 printk(KERN_ERR "Don't know first GPIO bank IRQ.\n");
 357                 return -EINVAL;
 358         }
 359
 360         clk = clk_get(NULL, "gpio");
 361         if (IS_ERR(clk)) {
 362                 printk(KERN_ERR "Error %ld getting gpio clock?\n",
 363                        PTR_ERR(clk));
 364                 return PTR_ERR(clk);
 365         }
 366         clk_enable(clk);
 367
 368         /* Arrange gpio_to_irq() support, handling either direct IRQs or
 369          * banked IRQs.  Having GPIOs in the first GPIO bank use direct
 370          * IRQs, while the others use banked IRQs, would need some setup
 371          * tweaks to recognize hardware which can do that.
 372          */
 373         for (gpio = 0, bank = 0; gpio < ngpio; bank++, gpio += 32) {
 374                 chips[bank].chip.to_irq = gpio_to_irq_banked;
 375                 chips[bank].irq_base = soc_info->gpio_unbanked
 376                         ? -EINVAL
 377                         : (soc_info->intc_irq_num + gpio);
 378         }
 379
 380         /*
 381          * AINTC can handle direct/unbanked IRQs for GPIOs, with the GPIO
 382          * controller only handling trigger modes.  We currently assume no
 383          * IRQ mux conflicts; gpio_irq_type_unbanked() is only for GPIOs.
 384          */
 385         if (soc_info->gpio_unbanked) {
 386                 static struct irq_chip gpio_irqchip_unbanked;
 387
 388                 /* pass "bank 0" GPIO IRQs to AINTC */
 389                 chips[0].chip.to_irq = gpio_to_irq_unbanked;
 390                 binten = BIT(0);
 391
 392                 /* AINTC handles mask/unmask; GPIO handles triggering */
 393                 irq = bank_irq;
 394                 gpio_irqchip_unbanked = *get_irq_desc_chip(irq_to_desc(irq));
 395                 gpio_irqchip_unbanked.name = "GPIO-AINTC";
 396                 gpio_irqchip_unbanked.set_type = gpio_irq_type_unbanked;
 397
 398                 /* default trigger: both edges */
 399                 g = gpio2regs(0);
 400                 __raw_writel(~0, &g->set_falling);
 401                 __raw_writel(~0, &g->set_rising);
 402
 403                 /* set the direct IRQs up to use that irqchip */
 404                 for (gpio = 0; gpio < soc_info->gpio_unbanked; gpio++, irq++) {
 405                         set_irq_chip(irq, &gpio_irqchip_unbanked);
 406                         set_irq_data(irq, (void *) __gpio_mask(gpio));
 407                         set_irq_chip_data(irq, (__force void *) g);
 408                         irq_desc[irq].status |= IRQ_TYPE_EDGE_BOTH;
 409                 }
 410
 411                 goto done;
 412         }
 413
 414         /*
 415          * Or, AINTC can handle IRQs for banks of 16 GPIO IRQs, which we
 416          * then chain through our own handler.
 417          */
 418         for (gpio = 0, irq = gpio_to_irq(0), bank = 0;
 419                         gpio < ngpio;
 420                         bank++, bank_irq++) {
 421                 unsigned                i;
 422
 423                 /* disabled by default, enabled only as needed */
 424                 g = gpio2regs(gpio);
 425                 __raw_writel(~0, &g->clr_falling);
 426                 __raw_writel(~0, &g->clr_rising);
 427
 428                 /* set up all irqs in this bank */
 429                 set_irq_chained_handler(bank_irq, gpio_irq_handler);
 430                 set_irq_chip_data(bank_irq, (__force void *) g);
 431                 set_irq_data(bank_irq, (void *) irq);
 432
 433                 for (i = 0; i < 16 && gpio < ngpio; i++, irq++, gpio++) {
 434                         set_irq_chip(irq, &gpio_irqchip);
 435                         set_irq_chip_data(irq, (__force void *) g);
 436                         set_irq_data(irq, (void *) __gpio_mask(gpio));
 437                         set_irq_handler(irq, handle_simple_irq);
 438                         set_irq_flags(irq, IRQF_VALID);
 439                 }
 440
 441                 binten |= BIT(bank);
 442         }
 443
 444 done:
 445         /* BINTEN -- per-bank interrupt enable. genirq would also let these
 446          * bits be set/cleared dynamically.
 447          */
 448         __raw_writel(binten, soc_info->gpio_base + 0x08);
 449
 450         printk(KERN_INFO "DaVinci: %d gpio irqs\n", irq - gpio_to_irq(0));
 451
 452         return 0;
 453 }