drivers/gpio/timbgpio.c

   1 /*
   2  * timbgpio.c timberdale FPGA GPIO driver
   3  * Copyright (c) 2009 Intel Corporation
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17  */
  18
  19 /* Supports:
  20  * Timberdale FPGA GPIO
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/gpio.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/irq.h>
  27 #include <linux/io.h>
  28 #include <linux/timb_gpio.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/slab.h>
  31
  32 #define DRIVER_NAME "timb-gpio"
  33
  34 #define TGPIOVAL        0x00
  35 #define TGPIODIR        0x04
  36 #define TGPIO_IER       0x08
  37 #define TGPIO_ISR       0x0c
  38 #define TGPIO_IPR       0x10
  39 #define TGPIO_ICR       0x14
  40 #define TGPIO_FLR       0x18
  41 #define TGPIO_LVR       0x1c
  42 #define TGPIO_VER       0x20
  43 #define TGPIO_BFLR      0x24
  44
  45 struct timbgpio {
  46         void __iomem            *membase;
  47         spinlock_t              lock; /* mutual exclusion */
  48         struct gpio_chip        gpio;
  49         int                     irq_base;
  50         unsigned long           last_ier;
  51 };
  52
  53 static int timbgpio_update_bit(struct gpio_chip *gpio, unsigned index,
  54         unsigned offset, bool enabled)
  55 {
  56         struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);
  57         u32 reg;
  58
  59         spin_lock(&tgpio->lock);
  60         reg = ioread32(tgpio->membase + offset);
  61
  62         if (enabled)
  63                 reg |= (1 << index);
  64         else
  65                 reg &= ~(1 << index);
  66
  67         iowrite32(reg, tgpio->membase + offset);
  68         spin_unlock(&tgpio->lock);
  69
  70         return 0;
  71 }
  72
  73 static int timbgpio_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
  74 {
  75         return timbgpio_update_bit(gpio, nr, TGPIODIR, true);
  76 }
  77
  78 static int timbgpio_gpio_get(struct gpio_chip *gpio, unsigned nr)
  79 {
  80         struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);
  81         u32 value;
  82
  83         value = ioread32(tgpio->membase + TGPIOVAL);
  84         return (value & (1 << nr)) ? 1 : 0;
  85 }
  86
  87 static int timbgpio_gpio_direction_output(struct gpio_chip *gpio,
  88                                                 unsigned nr, int val)
  89 {
  90         return timbgpio_update_bit(gpio, nr, TGPIODIR, false);
  91 }
  92
  93 static void timbgpio_gpio_set(struct gpio_chip *gpio,
  94                                 unsigned nr, int val)
  95 {
  96         timbgpio_update_bit(gpio, nr, TGPIOVAL, val != 0);
  97 }
  98
  99 static int timbgpio_to_irq(struct gpio_chip *gpio, unsigned offset)
 100 {
 101         struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);
 102
 103         if (tgpio->irq_base <= 0)
 104                 return -EINVAL;
 105
 106         return tgpio->irq_base + offset;
 107 }
 108
 109 /*
 110  * GPIO IRQ
 111  */
 112 static void timbgpio_irq_disable(struct irq_data *d)
 113 {
 114         struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
 115         int offset = d->irq - tgpio->irq_base;
 116         unsigned long flags;
 117
 118         spin_lock_irqsave(&tgpio->lock, flags);
 119         tgpio->last_ier &= ~(1 << offset);
 120         iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
 121         spin_unlock_irqrestore(&tgpio->lock, flags);
 122 }
 123
 124 static void timbgpio_irq_enable(struct irq_data *d)
 125 {
 126         struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
 127         int offset = d->irq - tgpio->irq_base;
 128         unsigned long flags;
 129
 130         spin_lock_irqsave(&tgpio->lock, flags);
 131         tgpio->last_ier |= 1 << offset;
 132         iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
 133         spin_unlock_irqrestore(&tgpio->lock, flags);
 134 }
 135
 136 static int timbgpio_irq_type(struct irq_data *d, unsigned trigger)
 137 {
 138         struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
 139         int offset = d->irq - tgpio->irq_base;
 140         unsigned long flags;
 141         u32 lvr, flr, bflr = 0;
 142         u32 ver;
 143         int ret = 0;
 144
 145         if (offset < 0 || offset > tgpio->gpio.ngpio)
 146                 return -EINVAL;
 147
 148         ver = ioread32(tgpio->membase + TGPIO_VER);
 149
 150         spin_lock_irqsave(&tgpio->lock, flags);
 151
 152         lvr = ioread32(tgpio->membase + TGPIO_LVR);
 153         flr = ioread32(tgpio->membase + TGPIO_FLR);
 154         if (ver > 2)
 155                 bflr = ioread32(tgpio->membase + TGPIO_BFLR);
 156
 157         if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
 158                 bflr &= ~(1 << offset);
 159                 flr &= ~(1 << offset);
 160                 if (trigger & IRQ_TYPE_LEVEL_HIGH)
 161                         lvr |= 1 << offset;
 162                 else
 163                         lvr &= ~(1 << offset);
 164         }
 165
 166         if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
 167                 if (ver < 3) {
 168                         ret = -EINVAL;
 169                         goto out;
 170                 }
 171                 else {
 172                         flr |= 1 << offset;
 173                         bflr |= 1 << offset;
 174                 }
 175         } else {
 176                 bflr &= ~(1 << offset);
 177                 flr |= 1 << offset;
 178                 if (trigger & IRQ_TYPE_EDGE_FALLING)
 179                         lvr &= ~(1 << offset);
 180                 else
 181                         lvr |= 1 << offset;
 182         }
 183
 184         iowrite32(lvr, tgpio->membase + TGPIO_LVR);
 185         iowrite32(flr, tgpio->membase + TGPIO_FLR);
 186         if (ver > 2)
 187                 iowrite32(bflr, tgpio->membase + TGPIO_BFLR);
 188
 189         iowrite32(1 << offset, tgpio->membase + TGPIO_ICR);
 190
 191 out:
 192         spin_unlock_irqrestore(&tgpio->lock, flags);
 193         return ret;
 194 }
 195
 196 static void timbgpio_irq(unsigned int irq, struct irq_desc *desc)
 197 {
 198         struct timbgpio *tgpio = get_irq_data(irq);
 199         unsigned long ipr;
 200         int offset;
 201
 202         desc->irq_data.chip->irq_ack(irq_get_irq_data(irq));
 203         ipr = ioread32(tgpio->membase + TGPIO_IPR);
 204         iowrite32(ipr, tgpio->membase + TGPIO_ICR);
 205
 206         /*
 207          * Some versions of the hardware trash the IER register if more than
 208          * one interrupt is received simultaneously.
 209          */
 210         iowrite32(0, tgpio->membase + TGPIO_IER);
 211
 212         for_each_set_bit(offset, &ipr, tgpio->gpio.ngpio)
 213                 generic_handle_irq(timbgpio_to_irq(&tgpio->gpio, offset));
 214
 215         iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
 216 }
 217
 218 static struct irq_chip timbgpio_irqchip = {
 219         .name           = "GPIO",
 220         .irq_enable     = timbgpio_irq_enable,
 221         .irq_disable    = timbgpio_irq_disable,
 222         .irq_set_type   = timbgpio_irq_type,
 223 };
 224
 225 static int __devinit timbgpio_probe(struct platform_device *pdev)
 226 {
 227         int err, i;
 228         struct gpio_chip *gc;
 229         struct timbgpio *tgpio;
 230         struct resource *iomem;
 231         struct timbgpio_platform_data *pdata = pdev->dev.platform_data;
 232         int irq = platform_get_irq(pdev, 0);
 233
 234         if (!pdata || pdata->nr_pins > 32) {
 235                 err = -EINVAL;
 236                 goto err_mem;
 237         }
 238
 239         iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 240         if (!iomem) {
 241                 err = -EINVAL;
 242                 goto err_mem;
 243         }
 244
 245         tgpio = kzalloc(sizeof(*tgpio), GFP_KERNEL);
 246         if (!tgpio) {
 247                 err = -EINVAL;
 248                 goto err_mem;
 249         }
 250         tgpio->irq_base = pdata->irq_base;
 251
 252         spin_lock_init(&tgpio->lock);
 253
 254         if (!request_mem_region(iomem->start, resource_size(iomem),
 255                 DRIVER_NAME)) {
 256                 err = -EBUSY;
 257                 goto err_request;
 258         }
 259
 260         tgpio->membase = ioremap(iomem->start, resource_size(iomem));
 261         if (!tgpio->membase) {
 262                 err = -ENOMEM;
 263                 goto err_ioremap;
 264         }
 265
 266         gc = &tgpio->gpio;
 267
 268         gc->label = dev_name(&pdev->dev);
 269         gc->owner = THIS_MODULE;
 270         gc->dev = &pdev->dev;
 271         gc->direction_input = timbgpio_gpio_direction_input;
 272         gc->get = timbgpio_gpio_get;
 273         gc->direction_output = timbgpio_gpio_direction_output;
 274         gc->set = timbgpio_gpio_set;
 275         gc->to_irq = (irq >= 0 && tgpio->irq_base > 0) ? timbgpio_to_irq : NULL;
 276         gc->dbg_show = NULL;
 277         gc->base = pdata->gpio_base;
 278         gc->ngpio = pdata->nr_pins;
 279         gc->can_sleep = 0;
 280
 281         err = gpiochip_add(gc);
 282         if (err)
 283                 goto err_chipadd;
 284
 285         platform_set_drvdata(pdev, tgpio);
 286
 287         /* make sure to disable interrupts */
 288         iowrite32(0x0, tgpio->membase + TGPIO_IER);
 289
 290         if (irq < 0 || tgpio->irq_base <= 0)
 291                 return 0;
 292
 293         for (i = 0; i < pdata->nr_pins; i++) {
 294                 set_irq_chip_and_handler_name(tgpio->irq_base + i,
 295                         &timbgpio_irqchip, handle_simple_irq, "mux");
 296                 set_irq_chip_data(tgpio->irq_base + i, tgpio);
 297 #ifdef CONFIG_ARM
 298                 set_irq_flags(tgpio->irq_base + i, IRQF_VALID | IRQF_PROBE);
 299 #endif
 300         }
 301
 302         set_irq_data(irq, tgpio);
 303         set_irq_chained_handler(irq, timbgpio_irq);
 304
 305         return 0;
 306
 307 err_chipadd:
 308         iounmap(tgpio->membase);
 309 err_ioremap:
 310         release_mem_region(iomem->start, resource_size(iomem));
 311 err_request:
 312         kfree(tgpio);
 313 err_mem:
 314         printk(KERN_ERR DRIVER_NAME": Failed to register GPIOs: %d\n", err);
 315
 316         return err;
 317 }
 318
 319 static int __devexit timbgpio_remove(struct platform_device *pdev)
 320 {
 321         int err;
 322         struct timbgpio_platform_data *pdata = pdev->dev.platform_data;
 323         struct timbgpio *tgpio = platform_get_drvdata(pdev);
 324         struct resource *iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 325         int irq = platform_get_irq(pdev, 0);
 326
 327         if (irq >= 0 && tgpio->irq_base > 0) {
 328                 int i;
 329                 for (i = 0; i < pdata->nr_pins; i++) {
 330                         set_irq_chip(tgpio->irq_base + i, NULL);
 331                         set_irq_chip_data(tgpio->irq_base + i, NULL);
 332                 }
 333
 334                 set_irq_handler(irq, NULL);
 335                 set_irq_data(irq, NULL);
 336         }
 337
 338         err = gpiochip_remove(&tgpio->gpio);
 339         if (err)
 340                 printk(KERN_ERR DRIVER_NAME": failed to remove gpio_chip\n");
 341
 342         iounmap(tgpio->membase);
 343         release_mem_region(iomem->start, resource_size(iomem));
 344         kfree(tgpio);
 345
 346         platform_set_drvdata(pdev, NULL);
 347
 348         return 0;
 349 }
 350
 351 static struct platform_driver timbgpio_platform_driver = {
 352         .driver = {
 353                 .name   = DRIVER_NAME,
 354                 .owner  = THIS_MODULE,
 355         },
 356         .probe          = timbgpio_probe,
 357         .remove         = timbgpio_remove,
 358 };
 359
 360 /*--------------------------------------------------------------------------*/
 361
 362 static int __init timbgpio_init(void)
 363 {
 364         return platform_driver_register(&timbgpio_platform_driver);
 365 }
 366
 367 static void __exit timbgpio_exit(void)
 368 {
 369         platform_driver_unregister(&timbgpio_platform_driver);
 370 }
 371
 372 module_init(timbgpio_init);
 373 module_exit(timbgpio_exit);
 374
 375 MODULE_DESCRIPTION("Timberdale GPIO driver");
 376 MODULE_LICENSE("GPL v2");
 377 MODULE_AUTHOR("Mocean Laboratories");
 378 MODULE_ALIAS("platform:"DRIVER_NAME);
 379