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