drivers/gpio/intel_ich6_gpio.c

   1 /*
   2  * Copyright (c) 2012 The Chromium OS Authors.
   3  * SPDX-License-Identifier:     GPL-2.0+
   4  */
   5
   6 /*
   7  * This is a GPIO driver for Intel ICH6 and later. The x86 GPIOs are accessed
   8  * through the PCI bus. Each PCI device has 256 bytes of configuration space,
   9  * consisting of a standard header and a device-specific set of registers. PCI
  10  * bus 0, device 31, function 0 gives us access to the chipset GPIOs (among
  11  * other things). Within the PCI configuration space, the GPIOBASE register
  12  * tells us where in the device's I/O region we can find more registers to
  13  * actually access the GPIOs.
  14  *
  15  * PCI bus/device/function 0:1f:0  => PCI config registers
  16  *   PCI config register "GPIOBASE"
  17  *     PCI I/O space + [GPIOBASE]  => start of GPIO registers
  18  *       GPIO registers => gpio pin function, direction, value
  19  *
  20  *
  21  * Danger Will Robinson! Bank 0 (GPIOs 0-31) seems to be fairly stable. Most
  22  * ICH versions have more, but the decoding the matrix that describes them is
  23  * absurdly complex and constantly changing. We'll provide Bank 1 and Bank 2,
  24  * but they will ONLY work for certain unspecified chipsets because the offset
  25  * from GPIOBASE changes randomly. Even then, many GPIOs are unimplemented or
  26  * reserved or subject to arcane restrictions.
  27  */
  28
  29 #include <common.h>
  30 #include <dm.h>
  31 #include <errno.h>
  32 #include <fdtdec.h>
  33 #include <pch.h>
  34 #include <pci.h>
  35 #include <asm/gpio.h>
  36 #include <asm/io.h>
  37 #include <asm/pci.h>
  38
  39 DECLARE_GLOBAL_DATA_PTR;
  40
  41 #define GPIO_PER_BANK   32
  42
  43 struct ich6_bank_priv {
  44         /* These are I/O addresses */
  45         uint16_t use_sel;
  46         uint16_t io_sel;
  47         uint16_t lvl;
  48 };
  49
  50 #define GPIO_USESEL_OFFSET(x)   (x)
  51 #define GPIO_IOSEL_OFFSET(x)    (x + 4)
  52 #define GPIO_LVL_OFFSET(x)      (x + 8)
  53
  54 #define IOPAD_MODE_MASK                         0x7
  55 #define IOPAD_PULL_ASSIGN_SHIFT         7
  56 #define IOPAD_PULL_ASSIGN_MASK          (0x3 << IOPAD_PULL_ASSIGN_SHIFT)
  57 #define IOPAD_PULL_STRENGTH_SHIFT       9
  58 #define IOPAD_PULL_STRENGTH_MASK        (0x3 << IOPAD_PULL_STRENGTH_SHIFT)
  59
  60 /* TODO: Move this to device tree, or platform data */
  61 void ich_gpio_set_gpio_map(const struct pch_gpio_map *map)
  62 {
  63         gd->arch.gpio_map = map;
  64 }
  65
  66 static int _ich6_gpio_set_value(uint16_t base, unsigned offset, int value)
  67 {
  68         u32 val;
  69
  70         val = inl(base);
  71         if (value)
  72                 val |= (1UL << offset);
  73         else
  74                 val &= ~(1UL << offset);
  75         outl(val, base);
  76
  77         return 0;
  78 }
  79
  80 static int _ich6_gpio_set_function(uint16_t base, unsigned offset, int func)
  81 {
  82         u32 val;
  83
  84         if (func) {
  85                 val = inl(base);
  86                 val |= (1UL << offset);
  87                 outl(val, base);
  88         } else {
  89                 val = inl(base);
  90                 val &= ~(1UL << offset);
  91                 outl(val, base);
  92         }
  93
  94         return 0;
  95 }
  96
  97 static int _ich6_gpio_set_direction(uint16_t base, unsigned offset, int dir)
  98 {
  99         u32 val;
 100
 101         if (!dir) {
 102                 val = inl(base);
 103                 val |= (1UL << offset);
 104                 outl(val, base);
 105         } else {
 106                 val = inl(base);
 107                 val &= ~(1UL << offset);
 108                 outl(val, base);
 109         }
 110
 111         return 0;
 112 }
 113
 114 static int _gpio_ich6_pinctrl_cfg_pin(s32 gpiobase, s32 iobase, int pin_node)
 115 {
 116         u32 gpio_offset[2];
 117         int pad_offset;
 118         int val;
 119         int ret;
 120         const void *prop;
 121
 122         /*
 123          * GPIO node is not mandatory, so we only do the
 124          * pinmuxing if the node exist.
 125          */
 126         ret = fdtdec_get_int_array(gd->fdt_blob, pin_node, "gpio-offset",
 127                              gpio_offset, 2);
 128         if (!ret) {
 129                 /* Do we want to force the GPIO mode? */
 130                 prop = fdt_getprop(gd->fdt_blob, pin_node, "mode-gpio",
 131                                       NULL);
 132                 if (prop)
 133                         _ich6_gpio_set_function(GPIO_USESEL_OFFSET
 134                                                 (gpiobase) +
 135                                                 gpio_offset[0],
 136                                                 gpio_offset[1], 1);
 137
 138                 val =
 139                     fdtdec_get_int(gd->fdt_blob, pin_node, "direction", -1);
 140                 if (val != -1)
 141                         _ich6_gpio_set_direction(GPIO_IOSEL_OFFSET
 142                                                  (gpiobase) +
 143                                                  gpio_offset[0],
 144                                                  gpio_offset[1], val);
 145
 146                 val =
 147                     fdtdec_get_int(gd->fdt_blob, pin_node, "output-value", -1);
 148                 if (val != -1)
 149                         _ich6_gpio_set_value(GPIO_LVL_OFFSET(gpiobase)
 150                                              + gpio_offset[0],
 151                                              gpio_offset[1], val);
 152         }
 153
 154         /* if iobase is present, let's configure the pad */
 155         if (iobase != -1) {
 156                 int iobase_addr;
 157
 158                 /*
 159                  * The offset for the same pin for the IOBASE and GPIOBASE are
 160                  * different, so instead of maintaining a lookup table,
 161                  * the device tree should provide directly the correct
 162                  * value for both mapping.
 163                  */
 164                 pad_offset =
 165                     fdtdec_get_int(gd->fdt_blob, pin_node, "pad-offset", -1);
 166                 if (pad_offset == -1) {
 167                         debug("%s: Invalid register io offset %d\n",
 168                               __func__, pad_offset);
 169                         return -EINVAL;
 170                 }
 171
 172                 /* compute the absolute pad address */
 173                 iobase_addr = iobase + pad_offset;
 174
 175                 /*
 176                  * Do we need to set a specific function mode?
 177                  * If someone put also 'mode-gpio', this option will
 178                  * be just ignored by the controller
 179                  */
 180                 val = fdtdec_get_int(gd->fdt_blob, pin_node, "mode-func", -1);
 181                 if (val != -1)
 182                         clrsetbits_le32(iobase_addr, IOPAD_MODE_MASK, val);
 183
 184                 /* Configure the pull-up/down if needed */
 185                 val = fdtdec_get_int(gd->fdt_blob, pin_node, "pull-assign", -1);
 186                 if (val != -1)
 187                         clrsetbits_le32(iobase_addr,
 188                                         IOPAD_PULL_ASSIGN_MASK,
 189                                         val << IOPAD_PULL_ASSIGN_SHIFT);
 190
 191                 val =
 192                     fdtdec_get_int(gd->fdt_blob, pin_node, "pull-strength", -1);
 193                 if (val != -1)
 194                         clrsetbits_le32(iobase_addr,
 195                                         IOPAD_PULL_STRENGTH_MASK,
 196                                         val << IOPAD_PULL_STRENGTH_SHIFT);
 197
 198                 debug("%s: pad cfg [0x%x]: %08x\n", __func__, pad_offset,
 199                       readl(iobase_addr));
 200         }
 201
 202         return 0;
 203 }
 204
 205 int gpio_ich6_pinctrl_init(void)
 206 {
 207         struct udevice *pch;
 208         int pin_node;
 209         int node;
 210         int ret;
 211         u32 gpiobase;
 212         u32 iobase = -1;
 213
 214         ret = uclass_first_device(UCLASS_PCH, &pch);
 215         if (ret)
 216                 return ret;
 217         if (!pch)
 218                 return -ENODEV;
 219
 220         /*
 221          * Get the memory/io base address to configure every pins.
 222          * IOBASE is used to configure the mode/pads
 223          * GPIOBASE is used to configure the direction and default value
 224          */
 225         ret = pch_get_gpio_base(pch, &gpiobase);
 226         if (ret) {
 227                 debug("%s: invalid GPIOBASE address (%08x)\n", __func__,
 228                       gpiobase);
 229                 return -EINVAL;
 230         }
 231
 232         /* This is not an error to not have a pinctrl node */
 233         node =
 234             fdtdec_next_compatible(gd->fdt_blob, 0, COMPAT_INTEL_X86_PINCTRL);
 235         if (node <= 0) {
 236                 debug("%s: no pinctrl node\n", __func__);
 237                 return 0;
 238         }
 239
 240         /*
 241          * Get the IOBASE, this is not mandatory as this is not
 242          * supported by all the CPU
 243          */
 244         ret = pch_get_io_base(pch, &iobase);
 245         if (ret && ret != -ENOSYS) {
 246                 debug("%s: invalid IOBASE address (%08x)\n", __func__,
 247                       iobase);
 248                 return -EINVAL;
 249         }
 250
 251         for (pin_node = fdt_first_subnode(gd->fdt_blob, node);
 252              pin_node > 0;
 253              pin_node = fdt_next_subnode(gd->fdt_blob, pin_node)) {
 254                 /* Configure the pin */
 255                 ret = _gpio_ich6_pinctrl_cfg_pin(gpiobase, iobase, pin_node);
 256                 if (ret != 0) {
 257                         debug("%s: invalid configuration for the pin %d\n",
 258                               __func__, pin_node);
 259                         return ret;
 260                 }
 261         }
 262
 263         return 0;
 264 }
 265
 266 static int gpio_ich6_ofdata_to_platdata(struct udevice *dev)
 267 {
 268         struct ich6_bank_platdata *plat = dev_get_platdata(dev);
 269         u32 gpiobase;
 270         int offset;
 271         int ret;
 272
 273         ret = pch_get_gpio_base(dev->parent, &gpiobase);
 274         if (ret)
 275                 return ret;
 276
 277         offset = fdtdec_get_int(gd->fdt_blob, dev->of_offset, "reg", -1);
 278         if (offset == -1) {
 279                 debug("%s: Invalid register offset %d\n", __func__, offset);
 280                 return -EINVAL;
 281         }
 282         plat->base_addr = gpiobase + offset;
 283         plat->bank_name = fdt_getprop(gd->fdt_blob, dev->of_offset,
 284                                       "bank-name", NULL);
 285
 286         return 0;
 287 }
 288
 289 static int ich6_gpio_probe(struct udevice *dev)
 290 {
 291         struct ich6_bank_platdata *plat = dev_get_platdata(dev);
 292         struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
 293         struct ich6_bank_priv *bank = dev_get_priv(dev);
 294
 295         if (gd->arch.gpio_map) {
 296                 setup_pch_gpios(plat->base_addr, gd->arch.gpio_map);
 297                 gd->arch.gpio_map = NULL;
 298         }
 299
 300         uc_priv->gpio_count = GPIO_PER_BANK;
 301         uc_priv->bank_name = plat->bank_name;
 302         bank->use_sel = plat->base_addr;
 303         bank->io_sel = plat->base_addr + 4;
 304         bank->lvl = plat->base_addr + 8;
 305
 306         return 0;
 307 }
 308
 309 static int ich6_gpio_request(struct udevice *dev, unsigned offset,
 310                              const char *label)
 311 {
 312         struct ich6_bank_priv *bank = dev_get_priv(dev);
 313         u32 tmplong;
 314
 315         /*
 316          * Make sure that the GPIO pin we want isn't already in use for some
 317          * built-in hardware function. We have to check this for every
 318          * requested pin.
 319          */
 320         tmplong = inl(bank->use_sel);
 321         if (!(tmplong & (1UL << offset))) {
 322                 debug("%s: gpio %d is reserved for internal use\n", __func__,
 323                       offset);
 324                 return -EPERM;
 325         }
 326
 327         return 0;
 328 }
 329
 330 static int ich6_gpio_direction_input(struct udevice *dev, unsigned offset)
 331 {
 332         struct ich6_bank_priv *bank = dev_get_priv(dev);
 333
 334         return _ich6_gpio_set_direction(bank->io_sel, offset, 0);
 335 }
 336
 337 static int ich6_gpio_direction_output(struct udevice *dev, unsigned offset,
 338                                        int value)
 339 {
 340         int ret;
 341         struct ich6_bank_priv *bank = dev_get_priv(dev);
 342
 343         ret = _ich6_gpio_set_direction(bank->io_sel, offset, 1);
 344         if (ret)
 345                 return ret;
 346
 347         return _ich6_gpio_set_value(bank->lvl, offset, value);
 348 }
 349
 350 static int ich6_gpio_get_value(struct udevice *dev, unsigned offset)
 351 {
 352         struct ich6_bank_priv *bank = dev_get_priv(dev);
 353         u32 tmplong;
 354         int r;
 355
 356         tmplong = inl(bank->lvl);
 357         r = (tmplong & (1UL << offset)) ? 1 : 0;
 358         return r;
 359 }
 360
 361 static int ich6_gpio_set_value(struct udevice *dev, unsigned offset,
 362                                int value)
 363 {
 364         struct ich6_bank_priv *bank = dev_get_priv(dev);
 365         return _ich6_gpio_set_value(bank->lvl, offset, value);
 366 }
 367
 368 static int ich6_gpio_get_function(struct udevice *dev, unsigned offset)
 369 {
 370         struct ich6_bank_priv *bank = dev_get_priv(dev);
 371         u32 mask = 1UL << offset;
 372
 373         if (!(inl(bank->use_sel) & mask))
 374                 return GPIOF_FUNC;
 375         if (inl(bank->io_sel) & mask)
 376                 return GPIOF_INPUT;
 377         else
 378                 return GPIOF_OUTPUT;
 379 }
 380
 381 static const struct dm_gpio_ops gpio_ich6_ops = {
 382         .request                = ich6_gpio_request,
 383         .direction_input        = ich6_gpio_direction_input,
 384         .direction_output       = ich6_gpio_direction_output,
 385         .get_value              = ich6_gpio_get_value,
 386         .set_value              = ich6_gpio_set_value,
 387         .get_function           = ich6_gpio_get_function,
 388 };
 389
 390 static const struct udevice_id intel_ich6_gpio_ids[] = {
 391         { .compatible = "intel,ich6-gpio" },
 392         { }
 393 };
 394
 395 U_BOOT_DRIVER(gpio_ich6) = {
 396         .name   = "gpio_ich6",
 397         .id     = UCLASS_GPIO,
 398         .of_match = intel_ich6_gpio_ids,
 399         .ops    = &gpio_ich6_ops,
 400         .ofdata_to_platdata     = gpio_ich6_ofdata_to_platdata,
 401         .probe  = ich6_gpio_probe,
 402         .priv_auto_alloc_size = sizeof(struct ich6_bank_priv),
 403         .platdata_auto_alloc_size = sizeof(struct ich6_bank_platdata),
 404 };