drivers/gpio/gpio-cs5535.c

   1 /*
   2  * AMD CS5535/CS5536 GPIO driver
   3  * Copyright (C) 2006  Advanced Micro Devices, Inc.
   4  * Copyright (C) 2007-2009  Andres Salomon <dilinger@collabora.co.uk>
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of version 2 of the GNU General Public License
   8  * as published by the Free Software Foundation.
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/module.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/gpio.h>
  16 #include <linux/io.h>
  17 #include <linux/cs5535.h>
  18 #include <asm/msr.h>
  19
  20 #define DRV_NAME "cs5535-gpio"
  21
  22 /*
  23  * Some GPIO pins
  24  *  31-29,23 : reserved (always mask out)
  25  *  28       : Power Button
  26  *  26       : PME#
  27  *  22-16    : LPC
  28  *  14,15    : SMBus
  29  *  9,8      : UART1
  30  *  7        : PCI INTB
  31  *  3,4      : UART2/DDC
  32  *  2        : IDE_IRQ0
  33  *  1        : AC_BEEP
  34  *  0        : PCI INTA
  35  *
  36  * If a mask was not specified, allow all except
  37  * reserved and Power Button
  38  */
  39 #define GPIO_DEFAULT_MASK 0x0F7FFFFF
  40
  41 static ulong mask = GPIO_DEFAULT_MASK;
  42 module_param_named(mask, mask, ulong, 0444);
  43 MODULE_PARM_DESC(mask, "GPIO channel mask.");
  44
  45 static struct cs5535_gpio_chip {
  46         struct gpio_chip chip;
  47         resource_size_t base;
  48
  49         struct platform_device *pdev;
  50         spinlock_t lock;
  51 } cs5535_gpio_chip;
  52
  53 /*
  54  * The CS5535/CS5536 GPIOs support a number of extra features not defined
  55  * by the gpio_chip API, so these are exported.  For a full list of the
  56  * registers, see include/linux/cs5535.h.
  57  */
  58
  59 static void errata_outl(struct cs5535_gpio_chip *chip, u32 val,
  60                 unsigned int reg)
  61 {
  62         unsigned long addr = chip->base + 0x80 + reg;
  63
  64         /*
  65          * According to the CS5536 errata (#36), after suspend
  66          * a write to the high bank GPIO register will clear all
  67          * non-selected bits; the recommended workaround is a
  68          * read-modify-write operation.
  69          *
  70          * Don't apply this errata to the edge status GPIOs, as writing
  71          * to their lower bits will clear them.
  72          */
  73         if (reg != GPIO_POSITIVE_EDGE_STS && reg != GPIO_NEGATIVE_EDGE_STS) {
  74                 if (val & 0xffff)
  75                         val |= (inl(addr) & 0xffff); /* ignore the high bits */
  76                 else
  77                         val |= (inl(addr) ^ (val >> 16));
  78         }
  79         outl(val, addr);
  80 }
  81
  82 static void __cs5535_gpio_set(struct cs5535_gpio_chip *chip, unsigned offset,
  83                 unsigned int reg)
  84 {
  85         if (offset < 16)
  86                 /* low bank register */
  87                 outl(1 << offset, chip->base + reg);
  88         else
  89                 /* high bank register */
  90                 errata_outl(chip, 1 << (offset - 16), reg);
  91 }
  92
  93 void cs5535_gpio_set(unsigned offset, unsigned int reg)
  94 {
  95         struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
  96         unsigned long flags;
  97
  98         spin_lock_irqsave(&chip->lock, flags);
  99         __cs5535_gpio_set(chip, offset, reg);
 100         spin_unlock_irqrestore(&chip->lock, flags);
 101 }
 102 EXPORT_SYMBOL_GPL(cs5535_gpio_set);
 103
 104 static void __cs5535_gpio_clear(struct cs5535_gpio_chip *chip, unsigned offset,
 105                 unsigned int reg)
 106 {
 107         if (offset < 16)
 108                 /* low bank register */
 109                 outl(1 << (offset + 16), chip->base + reg);
 110         else
 111                 /* high bank register */
 112                 errata_outl(chip, 1 << offset, reg);
 113 }
 114
 115 void cs5535_gpio_clear(unsigned offset, unsigned int reg)
 116 {
 117         struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
 118         unsigned long flags;
 119
 120         spin_lock_irqsave(&chip->lock, flags);
 121         __cs5535_gpio_clear(chip, offset, reg);
 122         spin_unlock_irqrestore(&chip->lock, flags);
 123 }
 124 EXPORT_SYMBOL_GPL(cs5535_gpio_clear);
 125
 126 int cs5535_gpio_isset(unsigned offset, unsigned int reg)
 127 {
 128         struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
 129         unsigned long flags;
 130         long val;
 131
 132         spin_lock_irqsave(&chip->lock, flags);
 133         if (offset < 16)
 134                 /* low bank register */
 135                 val = inl(chip->base + reg);
 136         else {
 137                 /* high bank register */
 138                 val = inl(chip->base + 0x80 + reg);
 139                 offset -= 16;
 140         }
 141         spin_unlock_irqrestore(&chip->lock, flags);
 142
 143         return (val & (1 << offset)) ? 1 : 0;
 144 }
 145 EXPORT_SYMBOL_GPL(cs5535_gpio_isset);
 146
 147 int cs5535_gpio_set_irq(unsigned group, unsigned irq)
 148 {
 149         uint32_t lo, hi;
 150
 151         if (group > 7 || irq > 15)
 152                 return -EINVAL;
 153
 154         rdmsr(MSR_PIC_ZSEL_HIGH, lo, hi);
 155
 156         lo &= ~(0xF << (group * 4));
 157         lo |= (irq & 0xF) << (group * 4);
 158
 159         wrmsr(MSR_PIC_ZSEL_HIGH, lo, hi);
 160         return 0;
 161 }
 162 EXPORT_SYMBOL_GPL(cs5535_gpio_set_irq);
 163
 164 void cs5535_gpio_setup_event(unsigned offset, int pair, int pme)
 165 {
 166         struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
 167         uint32_t shift = (offset % 8) * 4;
 168         unsigned long flags;
 169         uint32_t val;
 170
 171         if (offset >= 24)
 172                 offset = GPIO_MAP_W;
 173         else if (offset >= 16)
 174                 offset = GPIO_MAP_Z;
 175         else if (offset >= 8)
 176                 offset = GPIO_MAP_Y;
 177         else
 178                 offset = GPIO_MAP_X;
 179
 180         spin_lock_irqsave(&chip->lock, flags);
 181         val = inl(chip->base + offset);
 182
 183         /* Clear whatever was there before */
 184         val &= ~(0xF << shift);
 185
 186         /* Set the new value */
 187         val |= ((pair & 7) << shift);
 188
 189         /* Set the PME bit if this is a PME event */
 190         if (pme)
 191                 val |= (1 << (shift + 3));
 192
 193         outl(val, chip->base + offset);
 194         spin_unlock_irqrestore(&chip->lock, flags);
 195 }
 196 EXPORT_SYMBOL_GPL(cs5535_gpio_setup_event);
 197
 198 /*
 199  * Generic gpio_chip API support.
 200  */
 201
 202 static int chip_gpio_request(struct gpio_chip *c, unsigned offset)
 203 {
 204         struct cs5535_gpio_chip *chip = (struct cs5535_gpio_chip *) c;
 205         unsigned long flags;
 206
 207         spin_lock_irqsave(&chip->lock, flags);
 208
 209         /* check if this pin is available */
 210         if ((mask & (1 << offset)) == 0) {
 211                 dev_info(&chip->pdev->dev,
 212                         "pin %u is not available (check mask)\n", offset);
 213                 spin_unlock_irqrestore(&chip->lock, flags);
 214                 return -EINVAL;
 215         }
 216
 217         /* disable output aux 1 & 2 on this pin */
 218         __cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_AUX1);
 219         __cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_AUX2);
 220
 221         /* disable input aux 1 on this pin */
 222         __cs5535_gpio_clear(chip, offset, GPIO_INPUT_AUX1);
 223
 224         spin_unlock_irqrestore(&chip->lock, flags);
 225
 226         return 0;
 227 }
 228
 229 static int chip_gpio_get(struct gpio_chip *chip, unsigned offset)
 230 {
 231         return cs5535_gpio_isset(offset, GPIO_READ_BACK);
 232 }
 233
 234 static void chip_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
 235 {
 236         if (val)
 237                 cs5535_gpio_set(offset, GPIO_OUTPUT_VAL);
 238         else
 239                 cs5535_gpio_clear(offset, GPIO_OUTPUT_VAL);
 240 }
 241
 242 static int chip_direction_input(struct gpio_chip *c, unsigned offset)
 243 {
 244         struct cs5535_gpio_chip *chip = (struct cs5535_gpio_chip *) c;
 245         unsigned long flags;
 246
 247         spin_lock_irqsave(&chip->lock, flags);
 248         __cs5535_gpio_set(chip, offset, GPIO_INPUT_ENABLE);
 249         __cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_ENABLE);
 250         spin_unlock_irqrestore(&chip->lock, flags);
 251
 252         return 0;
 253 }
 254
 255 static int chip_direction_output(struct gpio_chip *c, unsigned offset, int val)
 256 {
 257         struct cs5535_gpio_chip *chip = (struct cs5535_gpio_chip *) c;
 258         unsigned long flags;
 259
 260         spin_lock_irqsave(&chip->lock, flags);
 261
 262         __cs5535_gpio_set(chip, offset, GPIO_INPUT_ENABLE);
 263         __cs5535_gpio_set(chip, offset, GPIO_OUTPUT_ENABLE);
 264         if (val)
 265                 __cs5535_gpio_set(chip, offset, GPIO_OUTPUT_VAL);
 266         else
 267                 __cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_VAL);
 268
 269         spin_unlock_irqrestore(&chip->lock, flags);
 270
 271         return 0;
 272 }
 273
 274 static const char * const cs5535_gpio_names[] = {
 275         "GPIO0", "GPIO1", "GPIO2", "GPIO3",
 276         "GPIO4", "GPIO5", "GPIO6", "GPIO7",
 277         "GPIO8", "GPIO9", "GPIO10", "GPIO11",
 278         "GPIO12", "GPIO13", "GPIO14", "GPIO15",
 279         "GPIO16", "GPIO17", "GPIO18", "GPIO19",
 280         "GPIO20", "GPIO21", "GPIO22", NULL,
 281         "GPIO24", "GPIO25", "GPIO26", "GPIO27",
 282         "GPIO28", NULL, NULL, NULL,
 283 };
 284
 285 static struct cs5535_gpio_chip cs5535_gpio_chip = {
 286         .chip = {
 287                 .owner = THIS_MODULE,
 288                 .label = DRV_NAME,
 289
 290                 .base = 0,
 291                 .ngpio = 32,
 292                 .names = cs5535_gpio_names,
 293                 .request = chip_gpio_request,
 294
 295                 .get = chip_gpio_get,
 296                 .set = chip_gpio_set,
 297
 298                 .direction_input = chip_direction_input,
 299                 .direction_output = chip_direction_output,
 300         },
 301 };
 302
 303 static int cs5535_gpio_probe(struct platform_device *pdev)
 304 {
 305         struct resource *res;
 306         int err = -EIO;
 307         ulong mask_orig = mask;
 308
 309         /* There are two ways to get the GPIO base address; one is by
 310          * fetching it from MSR_LBAR_GPIO, the other is by reading the
 311          * PCI BAR info.  The latter method is easier (especially across
 312          * different architectures), so we'll stick with that for now.  If
 313          * it turns out to be unreliable in the face of crappy BIOSes, we
 314          * can always go back to using MSRs.. */
 315
 316         res = platform_get_resource(pdev, IORESOURCE_IO, 0);
 317         if (!res) {
 318                 dev_err(&pdev->dev, "can't fetch device resource info\n");
 319                 goto done;
 320         }
 321
 322         if (!request_region(res->start, resource_size(res), pdev->name)) {
 323                 dev_err(&pdev->dev, "can't request region\n");
 324                 goto done;
 325         }
 326
 327         /* set up the driver-specific struct */
 328         cs5535_gpio_chip.base = res->start;
 329         cs5535_gpio_chip.pdev = pdev;
 330         spin_lock_init(&cs5535_gpio_chip.lock);
 331
 332         dev_info(&pdev->dev, "reserved resource region %pR\n", res);
 333
 334         /* mask out reserved pins */
 335         mask &= 0x1F7FFFFF;
 336
 337         /* do not allow pin 28, Power Button, as there's special handling
 338          * in the PMC needed. (note 12, p. 48) */
 339         mask &= ~(1 << 28);
 340
 341         if (mask_orig != mask)
 342                 dev_info(&pdev->dev, "mask changed from 0x%08lX to 0x%08lX\n",
 343                                 mask_orig, mask);
 344
 345         /* finally, register with the generic GPIO API */
 346         err = gpiochip_add(&cs5535_gpio_chip.chip);
 347         if (err)
 348                 goto release_region;
 349
 350         return 0;
 351
 352 release_region:
 353         release_region(res->start, resource_size(res));
 354 done:
 355         return err;
 356 }
 357
 358 static int cs5535_gpio_remove(struct platform_device *pdev)
 359 {
 360         struct resource *r;
 361         int err;
 362
 363         err = gpiochip_remove(&cs5535_gpio_chip.chip);
 364         if (err) {
 365                 /* uhh? */
 366                 dev_err(&pdev->dev, "unable to remove gpio_chip?\n");
 367                 return err;
 368         }
 369
 370         r = platform_get_resource(pdev, IORESOURCE_IO, 0);
 371         release_region(r->start, resource_size(r));
 372         return 0;
 373 }
 374
 375 static struct platform_driver cs5535_gpio_driver = {
 376         .driver = {
 377                 .name = DRV_NAME,
 378                 .owner = THIS_MODULE,
 379         },
 380         .probe = cs5535_gpio_probe,
 381         .remove = cs5535_gpio_remove,
 382 };
 383
 384 module_platform_driver(cs5535_gpio_driver);
 385
 386 MODULE_AUTHOR("Andres Salomon <dilinger@queued.net>");
 387 MODULE_DESCRIPTION("AMD CS5535/CS5536 GPIO driver");
 388 MODULE_LICENSE("GPL");
 389 MODULE_ALIAS("platform:" DRV_NAME);