drivers/gpio/gpio-davinci.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 #include <linux/gpio.h>
  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 <asm/mach/irq.h>
  20
  21 struct davinci_gpio_regs {
  22         u32     dir;
  23         u32     out_data;
  24         u32     set_data;
  25         u32     clr_data;
  26         u32     in_data;
  27         u32     set_rising;
  28         u32     clr_rising;
  29         u32     set_falling;
  30         u32     clr_falling;
  31         u32     intstat;
  32 };
  33
  34 #define chip2controller(chip)   \
  35         container_of(chip, struct davinci_gpio_controller, chip)
  36
  37 static struct davinci_gpio_controller chips[DIV_ROUND_UP(DAVINCI_N_GPIO, 32)];
  38 static void __iomem *gpio_base;
  39
  40 static struct davinci_gpio_regs __iomem __init *gpio2regs(unsigned gpio)
  41 {
  42         void __iomem *ptr;
  43
  44         if (gpio < 32 * 1)
  45                 ptr = gpio_base + 0x10;
  46         else if (gpio < 32 * 2)
  47                 ptr = gpio_base + 0x38;
  48         else if (gpio < 32 * 3)
  49                 ptr = gpio_base + 0x60;
  50         else if (gpio < 32 * 4)
  51                 ptr = gpio_base + 0x88;
  52         else if (gpio < 32 * 5)
  53                 ptr = gpio_base + 0xb0;
  54         else
  55                 ptr = NULL;
  56         return ptr;
  57 }
  58
  59 static inline struct davinci_gpio_regs __iomem *irq2regs(int irq)
  60 {
  61         struct davinci_gpio_regs __iomem *g;
  62
  63         g = (__force struct davinci_gpio_regs __iomem *)irq_get_chip_data(irq);
  64
  65         return g;
  66 }
  67
  68 static int __init davinci_gpio_irq_setup(void);
  69
  70 /*--------------------------------------------------------------------------*/
  71
  72 /* board setup code *MUST* setup pinmux and enable the GPIO clock. */
  73 static inline int __davinci_direction(struct gpio_chip *chip,
  74                         unsigned offset, bool out, int value)
  75 {
  76         struct davinci_gpio_controller *d = chip2controller(chip);
  77         struct davinci_gpio_regs __iomem *g = d->regs;
  78         unsigned long flags;
  79         u32 temp;
  80         u32 mask = 1 << offset;
  81
  82         spin_lock_irqsave(&d->lock, flags);
  83         temp = __raw_readl(&g->dir);
  84         if (out) {
  85                 temp &= ~mask;
  86                 __raw_writel(mask, value ? &g->set_data : &g->clr_data);
  87         } else {
  88                 temp |= mask;
  89         }
  90         __raw_writel(temp, &g->dir);
  91         spin_unlock_irqrestore(&d->lock, flags);
  92
  93         return 0;
  94 }
  95
  96 static int davinci_direction_in(struct gpio_chip *chip, unsigned offset)
  97 {
  98         return __davinci_direction(chip, offset, false, 0);
  99 }
 100
 101 static int
 102 davinci_direction_out(struct gpio_chip *chip, unsigned offset, int value)
 103 {
 104         return __davinci_direction(chip, offset, true, value);
 105 }
 106
 107 /*
 108  * Read the pin's value (works even if it's set up as output);
 109  * returns zero/nonzero.
 110  *
 111  * Note that changes are synched to the GPIO clock, so reading values back
 112  * right after you've set them may give old values.
 113  */
 114 static int davinci_gpio_get(struct gpio_chip *chip, unsigned offset)
 115 {
 116         struct davinci_gpio_controller *d = chip2controller(chip);
 117         struct davinci_gpio_regs __iomem *g = d->regs;
 118
 119         return (1 << offset) & __raw_readl(&g->in_data);
 120 }
 121
 122 /*
 123  * Assuming the pin is muxed as a gpio output, set its output value.
 124  */
 125 static void
 126 davinci_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 127 {
 128         struct davinci_gpio_controller *d = chip2controller(chip);
 129         struct davinci_gpio_regs __iomem *g = d->regs;
 130
 131         __raw_writel((1 << offset), value ? &g->set_data : &g->clr_data);
 132 }
 133
 134 static int __init davinci_gpio_setup(void)
 135 {
 136         int i, base;
 137         unsigned ngpio;
 138         struct davinci_soc_info *soc_info = &davinci_soc_info;
 139         struct davinci_gpio_regs *regs;
 140
 141         if (soc_info->gpio_type != GPIO_TYPE_DAVINCI)
 142                 return 0;
 143
 144         /*
 145          * The gpio banks conceptually expose a segmented bitmap,
 146          * and "ngpio" is one more than the largest zero-based
 147          * bit index that's valid.
 148          */
 149         ngpio = soc_info->gpio_num;
 150         if (ngpio == 0) {
 151                 pr_err("GPIO setup:  how many GPIOs?\n");
 152                 return -EINVAL;
 153         }
 154
 155         if (WARN_ON(DAVINCI_N_GPIO < ngpio))
 156                 ngpio = DAVINCI_N_GPIO;
 157
 158         gpio_base = ioremap(soc_info->gpio_base, SZ_4K);
 159         if (WARN_ON(!gpio_base))
 160                 return -ENOMEM;
 161
 162         for (i = 0, base = 0; base < ngpio; i++, base += 32) {
 163                 chips[i].chip.label = "DaVinci";
 164
 165                 chips[i].chip.direction_input = davinci_direction_in;
 166                 chips[i].chip.get = davinci_gpio_get;
 167                 chips[i].chip.direction_output = davinci_direction_out;
 168                 chips[i].chip.set = davinci_gpio_set;
 169
 170                 chips[i].chip.base = base;
 171                 chips[i].chip.ngpio = ngpio - base;
 172                 if (chips[i].chip.ngpio > 32)
 173                         chips[i].chip.ngpio = 32;
 174
 175                 spin_lock_init(&chips[i].lock);
 176
 177                 regs = gpio2regs(base);
 178                 chips[i].regs = regs;
 179                 chips[i].set_data = &regs->set_data;
 180                 chips[i].clr_data = &regs->clr_data;
 181                 chips[i].in_data = &regs->in_data;
 182
 183                 gpiochip_add(&chips[i].chip);
 184         }
 185
 186         soc_info->gpio_ctlrs = chips;
 187         soc_info->gpio_ctlrs_num = DIV_ROUND_UP(ngpio, 32);
 188
 189         davinci_gpio_irq_setup();
 190         return 0;
 191 }
 192 pure_initcall(davinci_gpio_setup);
 193
 194 /*--------------------------------------------------------------------------*/
 195 /*
 196  * We expect irqs will normally be set up as input pins, but they can also be
 197  * used as output pins ... which is convenient for testing.
 198  *
 199  * NOTE:  The first few GPIOs also have direct INTC hookups in addition
 200  * to their GPIOBNK0 irq, with a bit less overhead.
 201  *
 202  * All those INTC hookups (direct, plus several IRQ banks) can also
 203  * serve as EDMA event triggers.
 204  */
 205
 206 static void gpio_irq_disable(struct irq_data *d)
 207 {
 208         struct davinci_gpio_regs __iomem *g = irq2regs(d->irq);
 209         u32 mask = (u32) irq_data_get_irq_handler_data(d);
 210
 211         __raw_writel(mask, &g->clr_falling);
 212         __raw_writel(mask, &g->clr_rising);
 213 }
 214
 215 static void gpio_irq_enable(struct irq_data *d)
 216 {
 217         struct davinci_gpio_regs __iomem *g = irq2regs(d->irq);
 218         u32 mask = (u32) irq_data_get_irq_handler_data(d);
 219         unsigned status = irqd_get_trigger_type(d);
 220
 221         status &= IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;
 222         if (!status)
 223                 status = IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;
 224
 225         if (status & IRQ_TYPE_EDGE_FALLING)
 226                 __raw_writel(mask, &g->set_falling);
 227         if (status & IRQ_TYPE_EDGE_RISING)
 228                 __raw_writel(mask, &g->set_rising);
 229 }
 230
 231 static int gpio_irq_type(struct irq_data *d, unsigned trigger)
 232 {
 233         if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
 234                 return -EINVAL;
 235
 236         return 0;
 237 }
 238
 239 static struct irq_chip gpio_irqchip = {
 240         .name           = "GPIO",
 241         .irq_enable     = gpio_irq_enable,
 242         .irq_disable    = gpio_irq_disable,
 243         .irq_set_type   = gpio_irq_type,
 244         .flags          = IRQCHIP_SET_TYPE_MASKED,
 245 };
 246
 247 static void
 248 gpio_irq_handler(unsigned irq, struct irq_desc *desc)
 249 {
 250         struct davinci_gpio_regs __iomem *g;
 251         u32 mask = 0xffff;
 252         struct davinci_gpio_controller *d;
 253
 254         d = (struct davinci_gpio_controller *)irq_desc_get_handler_data(desc);
 255         g = (struct davinci_gpio_regs __iomem *)d->regs;
 256
 257         /* we only care about one bank */
 258         if (irq & 1)
 259                 mask <<= 16;
 260
 261         /* temporarily mask (level sensitive) parent IRQ */
 262         desc->irq_data.chip->irq_mask(&desc->irq_data);
 263         desc->irq_data.chip->irq_ack(&desc->irq_data);
 264         while (1) {
 265                 u32             status;
 266                 int             n;
 267                 int             res;
 268
 269                 /* ack any irqs */
 270                 status = __raw_readl(&g->intstat) & mask;
 271                 if (!status)
 272                         break;
 273                 __raw_writel(status, &g->intstat);
 274
 275                 /* now demux them to the right lowlevel handler */
 276                 n = d->irq_base;
 277                 if (irq & 1) {
 278                         n += 16;
 279                         status >>= 16;
 280                 }
 281
 282                 while (status) {
 283                         res = ffs(status);
 284                         n += res;
 285                         generic_handle_irq(n - 1);
 286                         status >>= res;
 287                 }
 288         }
 289         desc->irq_data.chip->irq_unmask(&desc->irq_data);
 290         /* now it may re-trigger */
 291 }
 292
 293 static int gpio_to_irq_banked(struct gpio_chip *chip, unsigned offset)
 294 {
 295         struct davinci_gpio_controller *d = chip2controller(chip);
 296
 297         if (d->irq_base >= 0)
 298                 return d->irq_base + offset;
 299         else
 300                 return -ENODEV;
 301 }
 302
 303 static int gpio_to_irq_unbanked(struct gpio_chip *chip, unsigned offset)
 304 {
 305         struct davinci_soc_info *soc_info = &davinci_soc_info;
 306
 307         /* NOTE:  we assume for now that only irqs in the first gpio_chip
 308          * can provide direct-mapped IRQs to AINTC (up to 32 GPIOs).
 309          */
 310         if (offset < soc_info->gpio_unbanked)
 311                 return soc_info->gpio_irq + offset;
 312         else
 313                 return -ENODEV;
 314 }
 315
 316 static int gpio_irq_type_unbanked(struct irq_data *d, unsigned trigger)
 317 {
 318         struct davinci_gpio_regs __iomem *g = irq2regs(d->irq);
 319         u32 mask = (u32) irq_data_get_irq_handler_data(d);
 320
 321         if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
 322                 return -EINVAL;
 323
 324         __raw_writel(mask, (trigger & IRQ_TYPE_EDGE_FALLING)
 325                      ? &g->set_falling : &g->clr_falling);
 326         __raw_writel(mask, (trigger & IRQ_TYPE_EDGE_RISING)
 327                      ? &g->set_rising : &g->clr_rising);
 328
 329         return 0;
 330 }
 331
 332 /*
 333  * NOTE:  for suspend/resume, probably best to make a platform_device with
 334  * suspend_late/resume_resume calls hooking into results of the set_wake()
 335  * calls ... so if no gpios are wakeup events the clock can be disabled,
 336  * with outputs left at previously set levels, and so that VDD3P3V.IOPWDN0
 337  * (dm6446) can be set appropriately for GPIOV33 pins.
 338  */
 339
 340 static int __init davinci_gpio_irq_setup(void)
 341 {
 342         unsigned        gpio, irq, bank;
 343         struct clk      *clk;
 344         u32             binten = 0;
 345         unsigned        ngpio, bank_irq;
 346         struct davinci_soc_info *soc_info = &davinci_soc_info;
 347         struct davinci_gpio_regs        __iomem *g;
 348
 349         ngpio = soc_info->gpio_num;
 350
 351         bank_irq = soc_info->gpio_irq;
 352         if (bank_irq == 0) {
 353                 printk(KERN_ERR "Don't know first GPIO bank IRQ.\n");
 354                 return -EINVAL;
 355         }
 356
 357         clk = clk_get(NULL, "gpio");
 358         if (IS_ERR(clk)) {
 359                 printk(KERN_ERR "Error %ld getting gpio clock?\n",
 360                        PTR_ERR(clk));
 361                 return PTR_ERR(clk);
 362         }
 363         clk_enable(clk);
 364
 365         /* Arrange gpio_to_irq() support, handling either direct IRQs or
 366          * banked IRQs.  Having GPIOs in the first GPIO bank use direct
 367          * IRQs, while the others use banked IRQs, would need some setup
 368          * tweaks to recognize hardware which can do that.
 369          */
 370         for (gpio = 0, bank = 0; gpio < ngpio; bank++, gpio += 32) {
 371                 chips[bank].chip.to_irq = gpio_to_irq_banked;
 372                 chips[bank].irq_base = soc_info->gpio_unbanked
 373                         ? -EINVAL
 374                         : (soc_info->intc_irq_num + gpio);
 375         }
 376
 377         /*
 378          * AINTC can handle direct/unbanked IRQs for GPIOs, with the GPIO
 379          * controller only handling trigger modes.  We currently assume no
 380          * IRQ mux conflicts; gpio_irq_type_unbanked() is only for GPIOs.
 381          */
 382         if (soc_info->gpio_unbanked) {
 383                 static struct irq_chip gpio_irqchip_unbanked;
 384
 385                 /* pass "bank 0" GPIO IRQs to AINTC */
 386                 chips[0].chip.to_irq = gpio_to_irq_unbanked;
 387                 binten = BIT(0);
 388
 389                 /* AINTC handles mask/unmask; GPIO handles triggering */
 390                 irq = bank_irq;
 391                 gpio_irqchip_unbanked = *irq_get_chip(irq);
 392                 gpio_irqchip_unbanked.name = "GPIO-AINTC";
 393                 gpio_irqchip_unbanked.irq_set_type = gpio_irq_type_unbanked;
 394
 395                 /* default trigger: both edges */
 396                 g = gpio2regs(0);
 397                 __raw_writel(~0, &g->set_falling);
 398                 __raw_writel(~0, &g->set_rising);
 399
 400                 /* set the direct IRQs up to use that irqchip */
 401                 for (gpio = 0; gpio < soc_info->gpio_unbanked; gpio++, irq++) {
 402                         irq_set_chip(irq, &gpio_irqchip_unbanked);
 403                         irq_set_handler_data(irq, (void *)__gpio_mask(gpio));
 404                         irq_set_chip_data(irq, (__force void *)g);
 405                         irq_set_status_flags(irq, IRQ_TYPE_EDGE_BOTH);
 406                 }
 407
 408                 goto done;
 409         }
 410
 411         /*
 412          * Or, AINTC can handle IRQs for banks of 16 GPIO IRQs, which we
 413          * then chain through our own handler.
 414          */
 415         for (gpio = 0, irq = gpio_to_irq(0), bank = 0;
 416                         gpio < ngpio;
 417                         bank++, bank_irq++) {
 418                 unsigned                i;
 419
 420                 /* disabled by default, enabled only as needed */
 421                 g = gpio2regs(gpio);
 422                 __raw_writel(~0, &g->clr_falling);
 423                 __raw_writel(~0, &g->clr_rising);
 424
 425                 /* set up all irqs in this bank */
 426                 irq_set_chained_handler(bank_irq, gpio_irq_handler);
 427
 428                 /*
 429                  * Each chip handles 32 gpios, and each irq bank consists of 16
 430                  * gpio irqs. Pass the irq bank's corresponding controller to
 431                  * the chained irq handler.
 432                  */
 433                 irq_set_handler_data(bank_irq, &chips[gpio / 32]);
 434
 435                 for (i = 0; i < 16 && gpio < ngpio; i++, irq++, gpio++) {
 436                         irq_set_chip(irq, &gpio_irqchip);
 437                         irq_set_chip_data(irq, (__force void *)g);
 438                         irq_set_handler_data(irq, (void *)__gpio_mask(gpio));
 439                         irq_set_handler(irq, handle_simple_irq);
 440                         set_irq_flags(irq, IRQF_VALID);
 441                 }
 442
 443                 binten |= BIT(bank);
 444         }
 445
 446 done:
 447         /* BINTEN -- per-bank interrupt enable. genirq would also let these
 448          * bits be set/cleared dynamically.
 449          */
 450         __raw_writel(binten, gpio_base + 0x08);
 451
 452         printk(KERN_INFO "DaVinci: %d gpio irqs\n", irq - gpio_to_irq(0));
 453
 454         return 0;
 455 }