drivers/gpio/gpio-sta2x11.c

   1 /*
   2  * STMicroelectronics ConneXt (STA2X11) GPIO driver
   3  *
   4  * Copyright 2012 ST Microelectronics (Alessandro Rubini)
   5  * Based on gpio-ml-ioh.c, Copyright 2010 OKI Semiconductors Ltd.
   6  * Also based on previous sta2x11 work, Copyright 2011 Wind River Systems, Inc.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  15  * See the GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  20  *
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/kernel.h>
  25 #include <linux/slab.h>
  26 #include <linux/gpio.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/irq.h>
  29 #include <linux/pci.h>
  30 #include <linux/platform_device.h>
  31 #include <linux/mfd/sta2x11-mfd.h>
  32
  33 struct gsta_regs {
  34         u32 dat;                /* 0x00 */
  35         u32 dats;
  36         u32 datc;
  37         u32 pdis;
  38         u32 dir;                /* 0x10 */
  39         u32 dirs;
  40         u32 dirc;
  41         u32 unused_1c;
  42         u32 afsela;             /* 0x20 */
  43         u32 unused_24[7];
  44         u32 rimsc;              /* 0x40 */
  45         u32 fimsc;
  46         u32 is;
  47         u32 ic;
  48 };
  49
  50 struct gsta_gpio {
  51         spinlock_t                      lock;
  52         struct device                   *dev;
  53         void __iomem                    *reg_base;
  54         struct gsta_regs __iomem        *regs[GSTA_NR_BLOCKS];
  55         struct gpio_chip                gpio;
  56         int                             irq_base;
  57         /* FIXME: save the whole config here (AF, ...) */
  58         unsigned                        irq_type[GSTA_NR_GPIO];
  59 };
  60
  61 static inline struct gsta_regs __iomem *__regs(struct gsta_gpio *chip, int nr)
  62 {
  63         return chip->regs[nr / GSTA_GPIO_PER_BLOCK];
  64 }
  65
  66 static inline u32 __bit(int nr)
  67 {
  68         return 1U << (nr % GSTA_GPIO_PER_BLOCK);
  69 }
  70
  71 /*
  72  * gpio methods
  73  */
  74
  75 static void gsta_gpio_set(struct gpio_chip *gpio, unsigned nr, int val)
  76 {
  77         struct gsta_gpio *chip = gpiochip_get_data(gpio);
  78         struct gsta_regs __iomem *regs = __regs(chip, nr);
  79         u32 bit = __bit(nr);
  80
  81         if (val)
  82                 writel(bit, &regs->dats);
  83         else
  84                 writel(bit, &regs->datc);
  85 }
  86
  87 static int gsta_gpio_get(struct gpio_chip *gpio, unsigned nr)
  88 {
  89         struct gsta_gpio *chip = gpiochip_get_data(gpio);
  90         struct gsta_regs __iomem *regs = __regs(chip, nr);
  91         u32 bit = __bit(nr);
  92
  93         return !!(readl(&regs->dat) & bit);
  94 }
  95
  96 static int gsta_gpio_direction_output(struct gpio_chip *gpio, unsigned nr,
  97                                       int val)
  98 {
  99         struct gsta_gpio *chip = gpiochip_get_data(gpio);
 100         struct gsta_regs __iomem *regs = __regs(chip, nr);
 101         u32 bit = __bit(nr);
 102
 103         writel(bit, &regs->dirs);
 104         /* Data register after direction, otherwise pullup/down is selected */
 105         if (val)
 106                 writel(bit, &regs->dats);
 107         else
 108                 writel(bit, &regs->datc);
 109         return 0;
 110 }
 111
 112 static int gsta_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
 113 {
 114         struct gsta_gpio *chip = gpiochip_get_data(gpio);
 115         struct gsta_regs __iomem *regs = __regs(chip, nr);
 116         u32 bit = __bit(nr);
 117
 118         writel(bit, &regs->dirc);
 119         return 0;
 120 }
 121
 122 static int gsta_gpio_to_irq(struct gpio_chip *gpio, unsigned offset)
 123 {
 124         struct gsta_gpio *chip = gpiochip_get_data(gpio);
 125         return chip->irq_base + offset;
 126 }
 127
 128 static void gsta_gpio_setup(struct gsta_gpio *chip) /* called from probe */
 129 {
 130         struct gpio_chip *gpio = &chip->gpio;
 131
 132         /*
 133          * ARCH_NR_GPIOS is currently 256 and dynamic allocation starts
 134          * from the end. However, for compatibility, we need the first
 135          * ConneXt device to start from gpio 0: it's the main chipset
 136          * on most boards so documents and drivers assume gpio0..gpio127
 137          */
 138         static int gpio_base;
 139
 140         gpio->label = dev_name(chip->dev);
 141         gpio->owner = THIS_MODULE;
 142         gpio->direction_input = gsta_gpio_direction_input;
 143         gpio->get = gsta_gpio_get;
 144         gpio->direction_output = gsta_gpio_direction_output;
 145         gpio->set = gsta_gpio_set;
 146         gpio->dbg_show = NULL;
 147         gpio->base = gpio_base;
 148         gpio->ngpio = GSTA_NR_GPIO;
 149         gpio->can_sleep = false;
 150         gpio->to_irq = gsta_gpio_to_irq;
 151
 152         /*
 153          * After the first device, turn to dynamic gpio numbers.
 154          * For example, with ARCH_NR_GPIOS = 256 we can fit two cards
 155          */
 156         if (!gpio_base)
 157                 gpio_base = -1;
 158 }
 159
 160 /*
 161  * Special method: alternate functions and pullup/pulldown. This is only
 162  * invoked on startup to configure gpio's according to platform data.
 163  * FIXME : this functionality shall be managed (and exported to other drivers)
 164  * via the pin control subsystem.
 165  */
 166 static void gsta_set_config(struct gsta_gpio *chip, int nr, unsigned cfg)
 167 {
 168         struct gsta_regs __iomem *regs = __regs(chip, nr);
 169         unsigned long flags;
 170         u32 bit = __bit(nr);
 171         u32 val;
 172         int err = 0;
 173
 174         pr_info("%s: %p %i %i\n", __func__, chip, nr, cfg);
 175
 176         if (cfg == PINMUX_TYPE_NONE)
 177                 return;
 178
 179         /* Alternate function or not? */
 180         spin_lock_irqsave(&chip->lock, flags);
 181         val = readl(&regs->afsela);
 182         if (cfg == PINMUX_TYPE_FUNCTION)
 183                 val |= bit;
 184         else
 185                 val &= ~bit;
 186         writel(val | bit, &regs->afsela);
 187         if (cfg == PINMUX_TYPE_FUNCTION) {
 188                 spin_unlock_irqrestore(&chip->lock, flags);
 189                 return;
 190         }
 191
 192         /* not alternate function: set details */
 193         switch (cfg) {
 194         case PINMUX_TYPE_OUTPUT_LOW:
 195                 writel(bit, &regs->dirs);
 196                 writel(bit, &regs->datc);
 197                 break;
 198         case PINMUX_TYPE_OUTPUT_HIGH:
 199                 writel(bit, &regs->dirs);
 200                 writel(bit, &regs->dats);
 201                 break;
 202         case PINMUX_TYPE_INPUT:
 203                 writel(bit, &regs->dirc);
 204                 val = readl(&regs->pdis) | bit;
 205                 writel(val, &regs->pdis);
 206                 break;
 207         case PINMUX_TYPE_INPUT_PULLUP:
 208                 writel(bit, &regs->dirc);
 209                 val = readl(&regs->pdis) & ~bit;
 210                 writel(val, &regs->pdis);
 211                 writel(bit, &regs->dats);
 212                 break;
 213         case PINMUX_TYPE_INPUT_PULLDOWN:
 214                 writel(bit, &regs->dirc);
 215                 val = readl(&regs->pdis) & ~bit;
 216                 writel(val, &regs->pdis);
 217                 writel(bit, &regs->datc);
 218                 break;
 219         default:
 220                 err = 1;
 221         }
 222         spin_unlock_irqrestore(&chip->lock, flags);
 223         if (err)
 224                 pr_err("%s: chip %p, pin %i, cfg %i is invalid\n",
 225                        __func__, chip, nr, cfg);
 226 }
 227
 228 /*
 229  * Irq methods
 230  */
 231
 232 static void gsta_irq_disable(struct irq_data *data)
 233 {
 234         struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
 235         struct gsta_gpio *chip = gc->private;
 236         int nr = data->irq - chip->irq_base;
 237         struct gsta_regs __iomem *regs = __regs(chip, nr);
 238         u32 bit = __bit(nr);
 239         u32 val;
 240         unsigned long flags;
 241
 242         spin_lock_irqsave(&chip->lock, flags);
 243         if (chip->irq_type[nr] & IRQ_TYPE_EDGE_RISING) {
 244                 val = readl(&regs->rimsc) & ~bit;
 245                 writel(val, &regs->rimsc);
 246         }
 247         if (chip->irq_type[nr] & IRQ_TYPE_EDGE_FALLING) {
 248                 val = readl(&regs->fimsc) & ~bit;
 249                 writel(val, &regs->fimsc);
 250         }
 251         spin_unlock_irqrestore(&chip->lock, flags);
 252         return;
 253 }
 254
 255 static void gsta_irq_enable(struct irq_data *data)
 256 {
 257         struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
 258         struct gsta_gpio *chip = gc->private;
 259         int nr = data->irq - chip->irq_base;
 260         struct gsta_regs __iomem *regs = __regs(chip, nr);
 261         u32 bit = __bit(nr);
 262         u32 val;
 263         int type;
 264         unsigned long flags;
 265
 266         type = chip->irq_type[nr];
 267
 268         spin_lock_irqsave(&chip->lock, flags);
 269         val = readl(&regs->rimsc);
 270         if (type & IRQ_TYPE_EDGE_RISING)
 271                 writel(val | bit, &regs->rimsc);
 272         else
 273                 writel(val & ~bit, &regs->rimsc);
 274         val = readl(&regs->rimsc);
 275         if (type & IRQ_TYPE_EDGE_FALLING)
 276                 writel(val | bit, &regs->fimsc);
 277         else
 278                 writel(val & ~bit, &regs->fimsc);
 279         spin_unlock_irqrestore(&chip->lock, flags);
 280         return;
 281 }
 282
 283 static int gsta_irq_type(struct irq_data *d, unsigned int type)
 284 {
 285         struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
 286         struct gsta_gpio *chip = gc->private;
 287         int nr = d->irq - chip->irq_base;
 288
 289         /* We only support edge interrupts */
 290         if (!(type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING))) {
 291                 pr_debug("%s: unsupported type 0x%x\n", __func__, type);
 292                 return -EINVAL;
 293         }
 294
 295         chip->irq_type[nr] = type; /* used for enable/disable */
 296
 297         gsta_irq_enable(d);
 298         return 0;
 299 }
 300
 301 static irqreturn_t gsta_gpio_handler(int irq, void *dev_id)
 302 {
 303         struct gsta_gpio *chip = dev_id;
 304         struct gsta_regs __iomem *regs;
 305         u32 is;
 306         int i, nr, base;
 307         irqreturn_t ret = IRQ_NONE;
 308
 309         for (i = 0; i < GSTA_NR_BLOCKS; i++) {
 310                 regs = chip->regs[i];
 311                 base = chip->irq_base + i * GSTA_GPIO_PER_BLOCK;
 312                 while ((is = readl(&regs->is))) {
 313                         nr = __ffs(is);
 314                         irq = base + nr;
 315                         generic_handle_irq(irq);
 316                         writel(1 << nr, &regs->ic);
 317                         ret = IRQ_HANDLED;
 318                 }
 319         }
 320         return ret;
 321 }
 322
 323 static void gsta_alloc_irq_chip(struct gsta_gpio *chip)
 324 {
 325         struct irq_chip_generic *gc;
 326         struct irq_chip_type *ct;
 327
 328         gc = irq_alloc_generic_chip(KBUILD_MODNAME, 1, chip->irq_base,
 329                                      chip->reg_base, handle_simple_irq);
 330         gc->private = chip;
 331         ct = gc->chip_types;
 332
 333         ct->chip.irq_set_type = gsta_irq_type;
 334         ct->chip.irq_disable = gsta_irq_disable;
 335         ct->chip.irq_enable = gsta_irq_enable;
 336
 337         /* FIXME: this makes at most 32 interrupts. Request 0 by now */
 338         irq_setup_generic_chip(gc, 0 /* IRQ_MSK(GSTA_GPIO_PER_BLOCK) */, 0,
 339                                IRQ_NOREQUEST | IRQ_NOPROBE, 0);
 340
 341         /* Set up all all 128 interrupts: code from setup_generic_chip */
 342         {
 343                 struct irq_chip_type *ct = gc->chip_types;
 344                 int i, j;
 345                 for (j = 0; j < GSTA_NR_GPIO; j++) {
 346                         i = chip->irq_base + j;
 347                         irq_set_chip_and_handler(i, &ct->chip, ct->handler);
 348                         irq_set_chip_data(i, gc);
 349                         irq_clear_status_flags(i, IRQ_NOREQUEST | IRQ_NOPROBE);
 350                 }
 351                 gc->irq_cnt = i - gc->irq_base;
 352         }
 353 }
 354
 355 /* The platform device used here is instantiated by the MFD device */
 356 static int gsta_probe(struct platform_device *dev)
 357 {
 358         int i, err;
 359         struct pci_dev *pdev;
 360         struct sta2x11_gpio_pdata *gpio_pdata;
 361         struct gsta_gpio *chip;
 362         struct resource *res;
 363
 364         pdev = *(struct pci_dev **)dev_get_platdata(&dev->dev);
 365         gpio_pdata = dev_get_platdata(&pdev->dev);
 366
 367         if (gpio_pdata == NULL)
 368                 dev_err(&dev->dev, "no gpio config\n");
 369         pr_debug("gpio config: %p\n", gpio_pdata);
 370
 371         res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 372
 373         chip = devm_kzalloc(&dev->dev, sizeof(*chip), GFP_KERNEL);
 374         if (!chip)
 375                 return -ENOMEM;
 376         chip->dev = &dev->dev;
 377         chip->reg_base = devm_ioremap_resource(&dev->dev, res);
 378         if (IS_ERR(chip->reg_base))
 379                 return PTR_ERR(chip->reg_base);
 380
 381         for (i = 0; i < GSTA_NR_BLOCKS; i++) {
 382                 chip->regs[i] = chip->reg_base + i * 4096;
 383                 /* disable all irqs */
 384                 writel(0, &chip->regs[i]->rimsc);
 385                 writel(0, &chip->regs[i]->fimsc);
 386                 writel(~0, &chip->regs[i]->ic);
 387         }
 388         spin_lock_init(&chip->lock);
 389         gsta_gpio_setup(chip);
 390         if (gpio_pdata)
 391                 for (i = 0; i < GSTA_NR_GPIO; i++)
 392                         gsta_set_config(chip, i, gpio_pdata->pinconfig[i]);
 393
 394         /* 384 was used in previous code: be compatible for other drivers */
 395         err = irq_alloc_descs(-1, 384, GSTA_NR_GPIO, NUMA_NO_NODE);
 396         if (err < 0) {
 397                 dev_warn(&dev->dev, "sta2x11 gpio: Can't get irq base (%i)\n",
 398                          -err);
 399                 return err;
 400         }
 401         chip->irq_base = err;
 402         gsta_alloc_irq_chip(chip);
 403
 404         err = request_irq(pdev->irq, gsta_gpio_handler,
 405                              IRQF_SHARED, KBUILD_MODNAME, chip);
 406         if (err < 0) {
 407                 dev_err(&dev->dev, "sta2x11 gpio: Can't request irq (%i)\n",
 408                         -err);
 409                 goto err_free_descs;
 410         }
 411
 412         err = devm_gpiochip_add_data(&dev->dev, &chip->gpio, chip);
 413         if (err < 0) {
 414                 dev_err(&dev->dev, "sta2x11 gpio: Can't register (%i)\n",
 415                         -err);
 416                 goto err_free_irq;
 417         }
 418
 419         platform_set_drvdata(dev, chip);
 420         return 0;
 421
 422 err_free_irq:
 423         free_irq(pdev->irq, chip);
 424 err_free_descs:
 425         irq_free_descs(chip->irq_base, GSTA_NR_GPIO);
 426         return err;
 427 }
 428
 429 static struct platform_driver sta2x11_gpio_platform_driver = {
 430         .driver = {
 431                 .name   = "sta2x11-gpio",
 432         },
 433         .probe = gsta_probe,
 434 };
 435
 436 module_platform_driver(sta2x11_gpio_platform_driver);
 437
 438 MODULE_LICENSE("GPL v2");
 439 MODULE_DESCRIPTION("sta2x11_gpio GPIO driver");