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 };
  51
  52 static int timbgpio_update_bit(struct gpio_chip *gpio, unsigned index,
  53         unsigned offset, bool enabled)
  54 {
  55         struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);
  56         u32 reg;
  57
  58         spin_lock(&tgpio->lock);
  59         reg = ioread32(tgpio->membase + offset);
  60
  61         if (enabled)
  62                 reg |= (1 << index);
  63         else
  64                 reg &= ~(1 << index);
  65
  66         iowrite32(reg, tgpio->membase + offset);
  67         spin_unlock(&tgpio->lock);
  68
  69         return 0;
  70 }
  71
  72 static int timbgpio_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
  73 {
  74         return timbgpio_update_bit(gpio, nr, TGPIODIR, true);
  75 }
  76
  77 static int timbgpio_gpio_get(struct gpio_chip *gpio, unsigned nr)
  78 {
  79         struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);
  80         u32 value;
  81
  82         value = ioread32(tgpio->membase + TGPIOVAL);
  83         return (value & (1 << nr)) ? 1 : 0;
  84 }
  85
  86 static int timbgpio_gpio_direction_output(struct gpio_chip *gpio,
  87                                                 unsigned nr, int val)
  88 {
  89         return timbgpio_update_bit(gpio, nr, TGPIODIR, false);
  90 }
  91
  92 static void timbgpio_gpio_set(struct gpio_chip *gpio,
  93                                 unsigned nr, int val)
  94 {
  95         timbgpio_update_bit(gpio, nr, TGPIOVAL, val != 0);
  96 }
  97
  98 static int timbgpio_to_irq(struct gpio_chip *gpio, unsigned offset)
  99 {
 100         struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);
 101
 102         if (tgpio->irq_base <= 0)
 103                 return -EINVAL;
 104
 105         return tgpio->irq_base + offset;
 106 }
 107
 108 /*
 109  * GPIO IRQ
 110  */
 111 static void timbgpio_irq_disable(unsigned irq)
 112 {
 113         struct timbgpio *tgpio = get_irq_chip_data(irq);
 114         int offset = irq - tgpio->irq_base;
 115
 116         timbgpio_update_bit(&tgpio->gpio, offset, TGPIO_IER, 0);
 117 }
 118
 119 static void timbgpio_irq_enable(unsigned irq)
 120 {
 121         struct timbgpio *tgpio = get_irq_chip_data(irq);
 122         int offset = irq - tgpio->irq_base;
 123
 124         timbgpio_update_bit(&tgpio->gpio, offset, TGPIO_IER, 1);
 125 }
 126
 127 static int timbgpio_irq_type(unsigned irq, unsigned trigger)
 128 {
 129         struct timbgpio *tgpio = get_irq_chip_data(irq);
 130         int offset = irq - tgpio->irq_base;
 131         unsigned long flags;
 132         u32 lvr, flr, bflr = 0;
 133         u32 ver;
 134         int ret = 0;
 135
 136         if (offset < 0 || offset > tgpio->gpio.ngpio)
 137                 return -EINVAL;
 138
 139         ver = ioread32(tgpio->membase + TGPIO_VER);
 140
 141         spin_lock_irqsave(&tgpio->lock, flags);
 142
 143         lvr = ioread32(tgpio->membase + TGPIO_LVR);
 144         flr = ioread32(tgpio->membase + TGPIO_FLR);
 145         if (ver > 2)
 146                 bflr = ioread32(tgpio->membase + TGPIO_BFLR);
 147
 148         if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
 149                 bflr &= ~(1 << offset);
 150                 flr &= ~(1 << offset);
 151                 if (trigger & IRQ_TYPE_LEVEL_HIGH)
 152                         lvr |= 1 << offset;
 153                 else
 154                         lvr &= ~(1 << offset);
 155         }
 156
 157         if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
 158                 if (ver < 3) {
 159                         ret = -EINVAL;
 160                         goto out;
 161                 }
 162                 else {
 163                         flr |= 1 << offset;
 164                         bflr |= 1 << offset;
 165                 }
 166         } else {
 167                 bflr &= ~(1 << offset);
 168                 flr |= 1 << offset;
 169                 if (trigger & IRQ_TYPE_EDGE_FALLING)
 170                         lvr &= ~(1 << offset);
 171                 else
 172                         lvr |= 1 << offset;
 173         }
 174
 175         iowrite32(lvr, tgpio->membase + TGPIO_LVR);
 176         iowrite32(flr, tgpio->membase + TGPIO_FLR);
 177         if (ver > 2)
 178                 iowrite32(bflr, tgpio->membase + TGPIO_BFLR);
 179
 180         iowrite32(1 << offset, tgpio->membase + TGPIO_ICR);
 181
 182 out:
 183         spin_unlock_irqrestore(&tgpio->lock, flags);
 184         return ret;
 185 }
 186
 187 static void timbgpio_irq(unsigned int irq, struct irq_desc *desc)
 188 {
 189         struct timbgpio *tgpio = get_irq_data(irq);
 190         unsigned long ipr;
 191         int offset;
 192
 193         desc->chip->ack(irq);
 194         ipr = ioread32(tgpio->membase + TGPIO_IPR);
 195         iowrite32(ipr, tgpio->membase + TGPIO_ICR);
 196
 197         for_each_set_bit(offset, &ipr, tgpio->gpio.ngpio)
 198                 generic_handle_irq(timbgpio_to_irq(&tgpio->gpio, offset));
 199 }
 200
 201 static struct irq_chip timbgpio_irqchip = {
 202         .name           = "GPIO",
 203         .enable         = timbgpio_irq_enable,
 204         .disable        = timbgpio_irq_disable,
 205         .set_type       = timbgpio_irq_type,
 206 };
 207
 208 static int __devinit timbgpio_probe(struct platform_device *pdev)
 209 {
 210         int err, i;
 211         struct gpio_chip *gc;
 212         struct timbgpio *tgpio;
 213         struct resource *iomem;
 214         struct timbgpio_platform_data *pdata = pdev->dev.platform_data;
 215         int irq = platform_get_irq(pdev, 0);
 216
 217         if (!pdata || pdata->nr_pins > 32) {
 218                 err = -EINVAL;
 219                 goto err_mem;
 220         }
 221
 222         iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 223         if (!iomem) {
 224                 err = -EINVAL;
 225                 goto err_mem;
 226         }
 227
 228         tgpio = kzalloc(sizeof(*tgpio), GFP_KERNEL);
 229         if (!tgpio) {
 230                 err = -EINVAL;
 231                 goto err_mem;
 232         }
 233         tgpio->irq_base = pdata->irq_base;
 234
 235         spin_lock_init(&tgpio->lock);
 236
 237         if (!request_mem_region(iomem->start, resource_size(iomem),
 238                 DRIVER_NAME)) {
 239                 err = -EBUSY;
 240                 goto err_request;
 241         }
 242
 243         tgpio->membase = ioremap(iomem->start, resource_size(iomem));
 244         if (!tgpio->membase) {
 245                 err = -ENOMEM;
 246                 goto err_ioremap;
 247         }
 248
 249         gc = &tgpio->gpio;
 250
 251         gc->label = dev_name(&pdev->dev);
 252         gc->owner = THIS_MODULE;
 253         gc->dev = &pdev->dev;
 254         gc->direction_input = timbgpio_gpio_direction_input;
 255         gc->get = timbgpio_gpio_get;
 256         gc->direction_output = timbgpio_gpio_direction_output;
 257         gc->set = timbgpio_gpio_set;
 258         gc->to_irq = (irq >= 0 && tgpio->irq_base > 0) ? timbgpio_to_irq : NULL;
 259         gc->dbg_show = NULL;
 260         gc->base = pdata->gpio_base;
 261         gc->ngpio = pdata->nr_pins;
 262         gc->can_sleep = 0;
 263
 264         err = gpiochip_add(gc);
 265         if (err)
 266                 goto err_chipadd;
 267
 268         platform_set_drvdata(pdev, tgpio);
 269
 270         /* make sure to disable interrupts */
 271         iowrite32(0x0, tgpio->membase + TGPIO_IER);
 272
 273         if (irq < 0 || tgpio->irq_base <= 0)
 274                 return 0;
 275
 276         for (i = 0; i < pdata->nr_pins; i++) {
 277                 set_irq_chip_and_handler_name(tgpio->irq_base + i,
 278                         &timbgpio_irqchip, handle_simple_irq, "mux");
 279                 set_irq_chip_data(tgpio->irq_base + i, tgpio);
 280 #ifdef CONFIG_ARM
 281                 set_irq_flags(tgpio->irq_base + i, IRQF_VALID | IRQF_PROBE);
 282 #endif
 283         }
 284
 285         set_irq_data(irq, tgpio);
 286         set_irq_chained_handler(irq, timbgpio_irq);
 287
 288         return 0;
 289
 290 err_chipadd:
 291         iounmap(tgpio->membase);
 292 err_ioremap:
 293         release_mem_region(iomem->start, resource_size(iomem));
 294 err_request:
 295         kfree(tgpio);
 296 err_mem:
 297         printk(KERN_ERR DRIVER_NAME": Failed to register GPIOs: %d\n", err);
 298
 299         return err;
 300 }
 301
 302 static int __devexit timbgpio_remove(struct platform_device *pdev)
 303 {
 304         int err;
 305         struct timbgpio_platform_data *pdata = pdev->dev.platform_data;
 306         struct timbgpio *tgpio = platform_get_drvdata(pdev);
 307         struct resource *iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 308         int irq = platform_get_irq(pdev, 0);
 309
 310         if (irq >= 0 && tgpio->irq_base > 0) {
 311                 int i;
 312                 for (i = 0; i < pdata->nr_pins; i++) {
 313                         set_irq_chip(tgpio->irq_base + i, NULL);
 314                         set_irq_chip_data(tgpio->irq_base + i, NULL);
 315                 }
 316
 317                 set_irq_handler(irq, NULL);
 318                 set_irq_data(irq, NULL);
 319         }
 320
 321         err = gpiochip_remove(&tgpio->gpio);
 322         if (err)
 323                 printk(KERN_ERR DRIVER_NAME": failed to remove gpio_chip\n");
 324
 325         iounmap(tgpio->membase);
 326         release_mem_region(iomem->start, resource_size(iomem));
 327         kfree(tgpio);
 328
 329         platform_set_drvdata(pdev, NULL);
 330
 331         return 0;
 332 }
 333
 334 static struct platform_driver timbgpio_platform_driver = {
 335         .driver = {
 336                 .name   = DRIVER_NAME,
 337                 .owner  = THIS_MODULE,
 338         },
 339         .probe          = timbgpio_probe,
 340         .remove         = timbgpio_remove,
 341 };
 342
 343 /*--------------------------------------------------------------------------*/
 344
 345 static int __init timbgpio_init(void)
 346 {
 347         return platform_driver_register(&timbgpio_platform_driver);
 348 }
 349
 350 static void __exit timbgpio_exit(void)
 351 {
 352         platform_driver_unregister(&timbgpio_platform_driver);
 353 }
 354
 355 module_init(timbgpio_init);
 356 module_exit(timbgpio_exit);
 357
 358 MODULE_DESCRIPTION("Timberdale GPIO driver");
 359 MODULE_LICENSE("GPL v2");
 360 MODULE_AUTHOR("Mocean Laboratories");
 361 MODULE_ALIAS("platform:"DRIVER_NAME);
 362