arch/avr32/mach-at32ap/pio.c

   1 /*
   2  * Atmel PIO2 Port Multiplexer support
   3  *
   4  * Copyright (C) 2004-2006 Atmel Corporation
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #include <linux/clk.h>
  12 #include <linux/debugfs.h>
  13 #include <linux/fs.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/irq.h>
  16
  17 #include <asm/gpio.h>
  18 #include <asm/io.h>
  19
  20 #include <mach/portmux.h>
  21
  22 #include "pio.h"
  23
  24 #define MAX_NR_PIO_DEVICES              8
  25
  26 struct pio_device {
  27         struct gpio_chip chip;
  28         void __iomem *regs;
  29         const struct platform_device *pdev;
  30         struct clk *clk;
  31         u32 pinmux_mask;
  32         char name[8];
  33 };
  34
  35 static struct pio_device pio_dev[MAX_NR_PIO_DEVICES];
  36
  37 static struct pio_device *gpio_to_pio(unsigned int gpio)
  38 {
  39         struct pio_device *pio;
  40         unsigned int index;
  41
  42         index = gpio >> 5;
  43         if (index >= MAX_NR_PIO_DEVICES)
  44                 return NULL;
  45         pio = &pio_dev[index];
  46         if (!pio->regs)
  47                 return NULL;
  48
  49         return pio;
  50 }
  51
  52 /* Pin multiplexing API */
  53 static DEFINE_SPINLOCK(pio_lock);
  54
  55 void __init at32_select_periph(unsigned int port, u32 pin_mask,
  56                                unsigned int periph, unsigned long flags)
  57 {
  58         struct pio_device *pio;
  59
  60         /* assign and verify pio */
  61         pio = gpio_to_pio(port);
  62         if (unlikely(!pio)) {
  63                 printk(KERN_WARNING "pio: invalid port %u\n", port);
  64                 goto fail;
  65         }
  66
  67         /* Test if any of the requested pins is already muxed */
  68         spin_lock(&pio_lock);
  69         if (unlikely(pio->pinmux_mask & pin_mask)) {
  70                 printk(KERN_WARNING "%s: pin(s) busy (requested 0x%x, busy 0x%x)\n",
  71                        pio->name, pin_mask, pio->pinmux_mask & pin_mask);
  72                 spin_unlock(&pio_lock);
  73                 goto fail;
  74         }
  75
  76         pio->pinmux_mask |= pin_mask;
  77
  78         /* enable pull ups */
  79         pio_writel(pio, PUER, pin_mask);
  80
  81         /* select either peripheral A or B */
  82         if (periph)
  83                 pio_writel(pio, BSR, pin_mask);
  84         else
  85                 pio_writel(pio, ASR, pin_mask);
  86
  87         /* enable peripheral control */
  88         pio_writel(pio, PDR, pin_mask);
  89
  90         /* Disable pull ups if not requested. */
  91         if (!(flags & AT32_GPIOF_PULLUP))
  92                 pio_writel(pio, PUDR, pin_mask);
  93
  94         spin_unlock(&pio_lock);
  95
  96         return;
  97
  98 fail:
  99         dump_stack();
 100 }
 101
 102 void __init at32_select_gpio(unsigned int pin, unsigned long flags)
 103 {
 104         struct pio_device *pio;
 105         unsigned int pin_index = pin & 0x1f;
 106         u32 mask = 1 << pin_index;
 107
 108         pio = gpio_to_pio(pin);
 109         if (unlikely(!pio)) {
 110                 printk("pio: invalid pin %u\n", pin);
 111                 goto fail;
 112         }
 113
 114         if (unlikely(test_and_set_bit(pin_index, &pio->pinmux_mask))) {
 115                 printk("%s: pin %u is busy\n", pio->name, pin_index);
 116                 goto fail;
 117         }
 118
 119         if (flags & AT32_GPIOF_OUTPUT) {
 120                 if (flags & AT32_GPIOF_HIGH)
 121                         pio_writel(pio, SODR, mask);
 122                 else
 123                         pio_writel(pio, CODR, mask);
 124                 if (flags & AT32_GPIOF_MULTIDRV)
 125                         pio_writel(pio, MDER, mask);
 126                 else
 127                         pio_writel(pio, MDDR, mask);
 128                 pio_writel(pio, PUDR, mask);
 129                 pio_writel(pio, OER, mask);
 130         } else {
 131                 if (flags & AT32_GPIOF_PULLUP)
 132                         pio_writel(pio, PUER, mask);
 133                 else
 134                         pio_writel(pio, PUDR, mask);
 135                 if (flags & AT32_GPIOF_DEGLITCH)
 136                         pio_writel(pio, IFER, mask);
 137                 else
 138                         pio_writel(pio, IFDR, mask);
 139                 pio_writel(pio, ODR, mask);
 140         }
 141
 142         pio_writel(pio, PER, mask);
 143
 144         return;
 145
 146 fail:
 147         dump_stack();
 148 }
 149
 150 /*
 151  * Undo a previous pin reservation. Will not affect the hardware
 152  * configuration.
 153  */
 154 void at32_deselect_pin(unsigned int pin)
 155 {
 156         struct pio_device *pio;
 157         unsigned int pin_index = pin & 0x1f;
 158
 159         pio = gpio_to_pio(pin);
 160         if (unlikely(!pio)) {
 161                 printk("pio: invalid pin %u\n", pin);
 162                 dump_stack();
 163                 return;
 164         }
 165
 166         clear_bit(pin_index, &pio->pinmux_mask);
 167 }
 168
 169 /* Reserve a pin, preventing anyone else from changing its configuration. */
 170 void __init at32_reserve_pin(unsigned int pin)
 171 {
 172         struct pio_device *pio;
 173         unsigned int pin_index = pin & 0x1f;
 174
 175         pio = gpio_to_pio(pin);
 176         if (unlikely(!pio)) {
 177                 printk("pio: invalid pin %u\n", pin);
 178                 goto fail;
 179         }
 180
 181         if (unlikely(test_and_set_bit(pin_index, &pio->pinmux_mask))) {
 182                 printk("%s: pin %u is busy\n", pio->name, pin_index);
 183                 goto fail;
 184         }
 185
 186         return;
 187
 188 fail:
 189         dump_stack();
 190 }
 191
 192 /*--------------------------------------------------------------------------*/
 193
 194 /* GPIO API */
 195
 196 static int direction_input(struct gpio_chip *chip, unsigned offset)
 197 {
 198         struct pio_device *pio = container_of(chip, struct pio_device, chip);
 199         u32 mask = 1 << offset;
 200
 201         if (!(pio_readl(pio, PSR) & mask))
 202                 return -EINVAL;
 203
 204         pio_writel(pio, ODR, mask);
 205         return 0;
 206 }
 207
 208 static int gpio_get(struct gpio_chip *chip, unsigned offset)
 209 {
 210         struct pio_device *pio = container_of(chip, struct pio_device, chip);
 211
 212         return (pio_readl(pio, PDSR) >> offset) & 1;
 213 }
 214
 215 static void gpio_set(struct gpio_chip *chip, unsigned offset, int value);
 216
 217 static int direction_output(struct gpio_chip *chip, unsigned offset, int value)
 218 {
 219         struct pio_device *pio = container_of(chip, struct pio_device, chip);
 220         u32 mask = 1 << offset;
 221
 222         if (!(pio_readl(pio, PSR) & mask))
 223                 return -EINVAL;
 224
 225         gpio_set(chip, offset, value);
 226         pio_writel(pio, OER, mask);
 227         return 0;
 228 }
 229
 230 static void gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 231 {
 232         struct pio_device *pio = container_of(chip, struct pio_device, chip);
 233         u32 mask = 1 << offset;
 234
 235         if (value)
 236                 pio_writel(pio, SODR, mask);
 237         else
 238                 pio_writel(pio, CODR, mask);
 239 }
 240
 241 /*--------------------------------------------------------------------------*/
 242
 243 /* GPIO IRQ support */
 244
 245 static void gpio_irq_mask(unsigned irq)
 246 {
 247         unsigned                gpio = irq_to_gpio(irq);
 248         struct pio_device       *pio = &pio_dev[gpio >> 5];
 249
 250         pio_writel(pio, IDR, 1 << (gpio & 0x1f));
 251 }
 252
 253 static void gpio_irq_unmask(unsigned irq)
 254 {
 255         unsigned                gpio = irq_to_gpio(irq);
 256         struct pio_device       *pio = &pio_dev[gpio >> 5];
 257
 258         pio_writel(pio, IER, 1 << (gpio & 0x1f));
 259 }
 260
 261 static int gpio_irq_type(unsigned irq, unsigned type)
 262 {
 263         if (type != IRQ_TYPE_EDGE_BOTH && type != IRQ_TYPE_NONE)
 264                 return -EINVAL;
 265
 266         return 0;
 267 }
 268
 269 static struct irq_chip gpio_irqchip = {
 270         .name           = "gpio",
 271         .mask           = gpio_irq_mask,
 272         .unmask         = gpio_irq_unmask,
 273         .set_type       = gpio_irq_type,
 274 };
 275
 276 static void gpio_irq_handler(unsigned irq, struct irq_desc *desc)
 277 {
 278         struct pio_device       *pio = get_irq_chip_data(irq);
 279         unsigned                gpio_irq;
 280
 281         gpio_irq = (unsigned) get_irq_data(irq);
 282         for (;;) {
 283                 u32             isr;
 284                 struct irq_desc *d;
 285
 286                 /* ack pending GPIO interrupts */
 287                 isr = pio_readl(pio, ISR) & pio_readl(pio, IMR);
 288                 if (!isr)
 289                         break;
 290                 do {
 291                         int i;
 292
 293                         i = ffs(isr) - 1;
 294                         isr &= ~(1 << i);
 295
 296                         i += gpio_irq;
 297                         d = &irq_desc[i];
 298
 299                         d->handle_irq(i, d);
 300                 } while (isr);
 301         }
 302 }
 303
 304 static void __init
 305 gpio_irq_setup(struct pio_device *pio, int irq, int gpio_irq)
 306 {
 307         unsigned        i;
 308
 309         set_irq_chip_data(irq, pio);
 310         set_irq_data(irq, (void *) gpio_irq);
 311
 312         for (i = 0; i < 32; i++, gpio_irq++) {
 313                 set_irq_chip_data(gpio_irq, pio);
 314                 set_irq_chip_and_handler(gpio_irq, &gpio_irqchip,
 315                                 handle_simple_irq);
 316         }
 317
 318         set_irq_chained_handler(irq, gpio_irq_handler);
 319 }
 320
 321 /*--------------------------------------------------------------------------*/
 322
 323 #ifdef CONFIG_DEBUG_FS
 324
 325 #include <linux/seq_file.h>
 326
 327 /*
 328  * This shows more info than the generic gpio dump code:
 329  * pullups, deglitching, open drain drive.
 330  */
 331 static void pio_bank_show(struct seq_file *s, struct gpio_chip *chip)
 332 {
 333         struct pio_device *pio = container_of(chip, struct pio_device, chip);
 334         u32                     psr, osr, imr, pdsr, pusr, ifsr, mdsr;
 335         unsigned                i;
 336         u32                     mask;
 337         char                    bank;
 338
 339         psr = pio_readl(pio, PSR);
 340         osr = pio_readl(pio, OSR);
 341         imr = pio_readl(pio, IMR);
 342         pdsr = pio_readl(pio, PDSR);
 343         pusr = pio_readl(pio, PUSR);
 344         ifsr = pio_readl(pio, IFSR);
 345         mdsr = pio_readl(pio, MDSR);
 346
 347         bank = 'A' + pio->pdev->id;
 348
 349         for (i = 0, mask = 1; i < 32; i++, mask <<= 1) {
 350                 const char *label;
 351
 352                 label = gpiochip_is_requested(chip, i);
 353                 if (!label && (imr & mask))
 354                         label = "[irq]";
 355                 if (!label)
 356                         continue;
 357
 358                 seq_printf(s, " gpio-%-3d P%c%-2d (%-12s) %s %s %s",
 359                         chip->base + i, bank, i,
 360                         label,
 361                         (osr & mask) ? "out" : "in ",
 362                         (mask & pdsr) ? "hi" : "lo",
 363                         (mask & pusr) ? "  " : "up");
 364                 if (ifsr & mask)
 365                         seq_printf(s, " deglitch");
 366                 if ((osr & mdsr) & mask)
 367                         seq_printf(s, " open-drain");
 368                 if (imr & mask)
 369                         seq_printf(s, " irq-%d edge-both",
 370                                 gpio_to_irq(chip->base + i));
 371                 seq_printf(s, "\n");
 372         }
 373 }
 374
 375 #else
 376 #define pio_bank_show   NULL
 377 #endif
 378
 379
 380 /*--------------------------------------------------------------------------*/
 381
 382 static int __init pio_probe(struct platform_device *pdev)
 383 {
 384         struct pio_device *pio = NULL;
 385         int irq = platform_get_irq(pdev, 0);
 386         int gpio_irq_base = GPIO_IRQ_BASE + pdev->id * 32;
 387
 388         BUG_ON(pdev->id >= MAX_NR_PIO_DEVICES);
 389         pio = &pio_dev[pdev->id];
 390         BUG_ON(!pio->regs);
 391
 392         pio->chip.label = pio->name;
 393         pio->chip.base = pdev->id * 32;
 394         pio->chip.ngpio = 32;
 395         pio->chip.dev = &pdev->dev;
 396         pio->chip.owner = THIS_MODULE;
 397
 398         pio->chip.direction_input = direction_input;
 399         pio->chip.get = gpio_get;
 400         pio->chip.direction_output = direction_output;
 401         pio->chip.set = gpio_set;
 402         pio->chip.dbg_show = pio_bank_show;
 403
 404         gpiochip_add(&pio->chip);
 405
 406         gpio_irq_setup(pio, irq, gpio_irq_base);
 407
 408         platform_set_drvdata(pdev, pio);
 409
 410         printk(KERN_DEBUG "%s: base 0x%p, irq %d chains %d..%d\n",
 411                pio->name, pio->regs, irq, gpio_irq_base, gpio_irq_base + 31);
 412
 413         return 0;
 414 }
 415
 416 static struct platform_driver pio_driver = {
 417         .driver         = {
 418                 .name           = "pio",
 419         },
 420 };
 421
 422 static int __init pio_init(void)
 423 {
 424         return platform_driver_probe(&pio_driver, pio_probe);
 425 }
 426 postcore_initcall(pio_init);
 427
 428 void __init at32_init_pio(struct platform_device *pdev)
 429 {
 430         struct resource *regs;
 431         struct pio_device *pio;
 432
 433         if (pdev->id > MAX_NR_PIO_DEVICES) {
 434                 dev_err(&pdev->dev, "only %d PIO devices supported\n",
 435                         MAX_NR_PIO_DEVICES);
 436                 return;
 437         }
 438
 439         pio = &pio_dev[pdev->id];
 440         snprintf(pio->name, sizeof(pio->name), "pio%d", pdev->id);
 441
 442         regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 443         if (!regs) {
 444                 dev_err(&pdev->dev, "no mmio resource defined\n");
 445                 return;
 446         }
 447
 448         pio->clk = clk_get(&pdev->dev, "mck");
 449         if (IS_ERR(pio->clk))
 450                 /*
 451                  * This is a fatal error, but if we continue we might
 452                  * be so lucky that we manage to initialize the
 453                  * console and display this message...
 454                  */
 455                 dev_err(&pdev->dev, "no mck clock defined\n");
 456         else
 457                 clk_enable(pio->clk);
 458
 459         pio->pdev = pdev;
 460         pio->regs = ioremap(regs->start, regs->end - regs->start + 1);
 461
 462         /* start with irqs disabled and acked */
 463         pio_writel(pio, IDR, ~0UL);
 464         (void) pio_readl(pio, ISR);
 465 }