drivers/gpio/tc35892-gpio.c

   1 /*
   2  * Copyright (C) ST-Ericsson SA 2010
   3  *
   4  * License Terms: GNU General Public License, version 2
   5  * Author: Hanumath Prasad <hanumath.prasad@stericsson.com> for ST-Ericsson
   6  * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/init.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/slab.h>
  13 #include <linux/gpio.h>
  14 #include <linux/irq.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/mfd/tc35892.h>
  17
  18 /*
  19  * These registers are modified under the irq bus lock and cached to avoid
  20  * unnecessary writes in bus_sync_unlock.
  21  */
  22 enum { REG_IBE, REG_IEV, REG_IS, REG_IE };
  23
  24 #define CACHE_NR_REGS   4
  25 #define CACHE_NR_BANKS  3
  26
  27 struct tc35892_gpio {
  28         struct gpio_chip chip;
  29         struct tc35892 *tc35892;
  30         struct device *dev;
  31         struct mutex irq_lock;
  32
  33         int irq_base;
  34
  35         /* Caches of interrupt control registers for bus_lock */
  36         u8 regs[CACHE_NR_REGS][CACHE_NR_BANKS];
  37         u8 oldregs[CACHE_NR_REGS][CACHE_NR_BANKS];
  38 };
  39
  40 static inline struct tc35892_gpio *to_tc35892_gpio(struct gpio_chip *chip)
  41 {
  42         return container_of(chip, struct tc35892_gpio, chip);
  43 }
  44
  45 static int tc35892_gpio_get(struct gpio_chip *chip, unsigned offset)
  46 {
  47         struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
  48         struct tc35892 *tc35892 = tc35892_gpio->tc35892;
  49         u8 reg = TC35892_GPIODATA0 + (offset / 8) * 2;
  50         u8 mask = 1 << (offset % 8);
  51         int ret;
  52
  53         ret = tc35892_reg_read(tc35892, reg);
  54         if (ret < 0)
  55                 return ret;
  56
  57         return ret & mask;
  58 }
  59
  60 static void tc35892_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
  61 {
  62         struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
  63         struct tc35892 *tc35892 = tc35892_gpio->tc35892;
  64         u8 reg = TC35892_GPIODATA0 + (offset / 8) * 2;
  65         unsigned pos = offset % 8;
  66         u8 data[] = {!!val << pos, 1 << pos};
  67
  68         tc35892_block_write(tc35892, reg, ARRAY_SIZE(data), data);
  69 }
  70
  71 static int tc35892_gpio_direction_output(struct gpio_chip *chip,
  72                                          unsigned offset, int val)
  73 {
  74         struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
  75         struct tc35892 *tc35892 = tc35892_gpio->tc35892;
  76         u8 reg = TC35892_GPIODIR0 + offset / 8;
  77         unsigned pos = offset % 8;
  78
  79         tc35892_gpio_set(chip, offset, val);
  80
  81         return tc35892_set_bits(tc35892, reg, 1 << pos, 1 << pos);
  82 }
  83
  84 static int tc35892_gpio_direction_input(struct gpio_chip *chip,
  85                                         unsigned offset)
  86 {
  87         struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
  88         struct tc35892 *tc35892 = tc35892_gpio->tc35892;
  89         u8 reg = TC35892_GPIODIR0 + offset / 8;
  90         unsigned pos = offset % 8;
  91
  92         return tc35892_set_bits(tc35892, reg, 1 << pos, 0);
  93 }
  94
  95 static int tc35892_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
  96 {
  97         struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
  98
  99         return tc35892_gpio->irq_base + offset;
 100 }
 101
 102 static struct gpio_chip template_chip = {
 103         .label                  = "tc35892",
 104         .owner                  = THIS_MODULE,
 105         .direction_input        = tc35892_gpio_direction_input,
 106         .get                    = tc35892_gpio_get,
 107         .direction_output       = tc35892_gpio_direction_output,
 108         .set                    = tc35892_gpio_set,
 109         .to_irq                 = tc35892_gpio_to_irq,
 110         .can_sleep              = 1,
 111 };
 112
 113 static int tc35892_gpio_irq_set_type(unsigned int irq, unsigned int type)
 114 {
 115         struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
 116         int offset = irq - tc35892_gpio->irq_base;
 117         int regoffset = offset / 8;
 118         int mask = 1 << (offset % 8);
 119
 120         if (type == IRQ_TYPE_EDGE_BOTH) {
 121                 tc35892_gpio->regs[REG_IBE][regoffset] |= mask;
 122                 return 0;
 123         }
 124
 125         tc35892_gpio->regs[REG_IBE][regoffset] &= ~mask;
 126
 127         if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_LEVEL_HIGH)
 128                 tc35892_gpio->regs[REG_IS][regoffset] |= mask;
 129         else
 130                 tc35892_gpio->regs[REG_IS][regoffset] &= ~mask;
 131
 132         if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH)
 133                 tc35892_gpio->regs[REG_IEV][regoffset] |= mask;
 134         else
 135                 tc35892_gpio->regs[REG_IEV][regoffset] &= ~mask;
 136
 137         return 0;
 138 }
 139
 140 static void tc35892_gpio_irq_lock(unsigned int irq)
 141 {
 142         struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
 143
 144         mutex_lock(&tc35892_gpio->irq_lock);
 145 }
 146
 147 static void tc35892_gpio_irq_sync_unlock(unsigned int irq)
 148 {
 149         struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
 150         struct tc35892 *tc35892 = tc35892_gpio->tc35892;
 151         static const u8 regmap[] = {
 152                 [REG_IBE]       = TC35892_GPIOIBE0,
 153                 [REG_IEV]       = TC35892_GPIOIEV0,
 154                 [REG_IS]        = TC35892_GPIOIS0,
 155                 [REG_IE]        = TC35892_GPIOIE0,
 156         };
 157         int i, j;
 158
 159         for (i = 0; i < CACHE_NR_REGS; i++) {
 160                 for (j = 0; j < CACHE_NR_BANKS; j++) {
 161                         u8 old = tc35892_gpio->oldregs[i][j];
 162                         u8 new = tc35892_gpio->regs[i][j];
 163
 164                         if (new == old)
 165                                 continue;
 166
 167                         tc35892_gpio->oldregs[i][j] = new;
 168                         tc35892_reg_write(tc35892, regmap[i] + j * 8, new);
 169                 }
 170         }
 171
 172         mutex_unlock(&tc35892_gpio->irq_lock);
 173 }
 174
 175 static void tc35892_gpio_irq_mask(unsigned int irq)
 176 {
 177         struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
 178         int offset = irq - tc35892_gpio->irq_base;
 179         int regoffset = offset / 8;
 180         int mask = 1 << (offset % 8);
 181
 182         tc35892_gpio->regs[REG_IE][regoffset] &= ~mask;
 183 }
 184
 185 static void tc35892_gpio_irq_unmask(unsigned int irq)
 186 {
 187         struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
 188         int offset = irq - tc35892_gpio->irq_base;
 189         int regoffset = offset / 8;
 190         int mask = 1 << (offset % 8);
 191
 192         tc35892_gpio->regs[REG_IE][regoffset] |= mask;
 193 }
 194
 195 static struct irq_chip tc35892_gpio_irq_chip = {
 196         .name                   = "tc35892-gpio",
 197         .bus_lock               = tc35892_gpio_irq_lock,
 198         .bus_sync_unlock        = tc35892_gpio_irq_sync_unlock,
 199         .mask                   = tc35892_gpio_irq_mask,
 200         .unmask                 = tc35892_gpio_irq_unmask,
 201         .set_type               = tc35892_gpio_irq_set_type,
 202 };
 203
 204 static irqreturn_t tc35892_gpio_irq(int irq, void *dev)
 205 {
 206         struct tc35892_gpio *tc35892_gpio = dev;
 207         struct tc35892 *tc35892 = tc35892_gpio->tc35892;
 208         u8 status[CACHE_NR_BANKS];
 209         int ret;
 210         int i;
 211
 212         ret = tc35892_block_read(tc35892, TC35892_GPIOMIS0,
 213                                  ARRAY_SIZE(status), status);
 214         if (ret < 0)
 215                 return IRQ_NONE;
 216
 217         for (i = 0; i < ARRAY_SIZE(status); i++) {
 218                 unsigned int stat = status[i];
 219                 if (!stat)
 220                         continue;
 221
 222                 while (stat) {
 223                         int bit = __ffs(stat);
 224                         int line = i * 8 + bit;
 225
 226                         handle_nested_irq(tc35892_gpio->irq_base + line);
 227                         stat &= ~(1 << bit);
 228                 }
 229
 230                 tc35892_reg_write(tc35892, TC35892_GPIOIC0 + i, status[i]);
 231         }
 232
 233         return IRQ_HANDLED;
 234 }
 235
 236 static int tc35892_gpio_irq_init(struct tc35892_gpio *tc35892_gpio)
 237 {
 238         int base = tc35892_gpio->irq_base;
 239         int irq;
 240
 241         for (irq = base; irq < base + tc35892_gpio->chip.ngpio; irq++) {
 242                 set_irq_chip_data(irq, tc35892_gpio);
 243                 set_irq_chip_and_handler(irq, &tc35892_gpio_irq_chip,
 244                                          handle_simple_irq);
 245                 set_irq_nested_thread(irq, 1);
 246 #ifdef CONFIG_ARM
 247                 set_irq_flags(irq, IRQF_VALID);
 248 #else
 249                 set_irq_noprobe(irq);
 250 #endif
 251         }
 252
 253         return 0;
 254 }
 255
 256 static void tc35892_gpio_irq_remove(struct tc35892_gpio *tc35892_gpio)
 257 {
 258         int base = tc35892_gpio->irq_base;
 259         int irq;
 260
 261         for (irq = base; irq < base + tc35892_gpio->chip.ngpio; irq++) {
 262 #ifdef CONFIG_ARM
 263                 set_irq_flags(irq, 0);
 264 #endif
 265                 set_irq_chip_and_handler(irq, NULL, NULL);
 266                 set_irq_chip_data(irq, NULL);
 267         }
 268 }
 269
 270 static int __devinit tc35892_gpio_probe(struct platform_device *pdev)
 271 {
 272         struct tc35892 *tc35892 = dev_get_drvdata(pdev->dev.parent);
 273         struct tc35892_gpio_platform_data *pdata;
 274         struct tc35892_gpio *tc35892_gpio;
 275         int ret;
 276         int irq;
 277
 278         pdata = tc35892->pdata->gpio;
 279         if (!pdata)
 280                 return -ENODEV;
 281
 282         irq = platform_get_irq(pdev, 0);
 283         if (irq < 0)
 284                 return irq;
 285
 286         tc35892_gpio = kzalloc(sizeof(struct tc35892_gpio), GFP_KERNEL);
 287         if (!tc35892_gpio)
 288                 return -ENOMEM;
 289
 290         mutex_init(&tc35892_gpio->irq_lock);
 291
 292         tc35892_gpio->dev = &pdev->dev;
 293         tc35892_gpio->tc35892 = tc35892;
 294
 295         tc35892_gpio->chip = template_chip;
 296         tc35892_gpio->chip.ngpio = tc35892->num_gpio;
 297         tc35892_gpio->chip.dev = &pdev->dev;
 298         tc35892_gpio->chip.base = pdata->gpio_base;
 299
 300         tc35892_gpio->irq_base = tc35892->irq_base + TC35892_INT_GPIO(0);
 301
 302         /* Bring the GPIO module out of reset */
 303         ret = tc35892_set_bits(tc35892, TC35892_RSTCTRL,
 304                                TC35892_RSTCTRL_GPIRST, 0);
 305         if (ret < 0)
 306                 goto out_free;
 307
 308         ret = tc35892_gpio_irq_init(tc35892_gpio);
 309         if (ret)
 310                 goto out_free;
 311
 312         ret = request_threaded_irq(irq, NULL, tc35892_gpio_irq, IRQF_ONESHOT,
 313                                    "tc35892-gpio", tc35892_gpio);
 314         if (ret) {
 315                 dev_err(&pdev->dev, "unable to get irq: %d\n", ret);
 316                 goto out_removeirq;
 317         }
 318
 319         ret = gpiochip_add(&tc35892_gpio->chip);
 320         if (ret) {
 321                 dev_err(&pdev->dev, "unable to add gpiochip: %d\n", ret);
 322                 goto out_freeirq;
 323         }
 324
 325         platform_set_drvdata(pdev, tc35892_gpio);
 326
 327         return 0;
 328
 329 out_freeirq:
 330         free_irq(irq, tc35892_gpio);
 331 out_removeirq:
 332         tc35892_gpio_irq_remove(tc35892_gpio);
 333 out_free:
 334         kfree(tc35892_gpio);
 335         return ret;
 336 }
 337
 338 static int __devexit tc35892_gpio_remove(struct platform_device *pdev)
 339 {
 340         struct tc35892_gpio *tc35892_gpio = platform_get_drvdata(pdev);
 341         int irq = platform_get_irq(pdev, 0);
 342         int ret;
 343
 344         ret = gpiochip_remove(&tc35892_gpio->chip);
 345         if (ret < 0) {
 346                 dev_err(tc35892_gpio->dev,
 347                         "unable to remove gpiochip: %d\n", ret);
 348                 return ret;
 349         }
 350
 351         free_irq(irq, tc35892_gpio);
 352         tc35892_gpio_irq_remove(tc35892_gpio);
 353
 354         platform_set_drvdata(pdev, NULL);
 355         kfree(tc35892_gpio);
 356
 357         return 0;
 358 }
 359
 360 static struct platform_driver tc35892_gpio_driver = {
 361         .driver.name    = "tc35892-gpio",
 362         .driver.owner   = THIS_MODULE,
 363         .probe          = tc35892_gpio_probe,
 364         .remove         = __devexit_p(tc35892_gpio_remove),
 365 };
 366
 367 static int __init tc35892_gpio_init(void)
 368 {
 369         return platform_driver_register(&tc35892_gpio_driver);
 370 }
 371 subsys_initcall(tc35892_gpio_init);
 372
 373 static void __exit tc35892_gpio_exit(void)
 374 {
 375         platform_driver_unregister(&tc35892_gpio_driver);
 376 }
 377 module_exit(tc35892_gpio_exit);
 378
 379 MODULE_LICENSE("GPL v2");
 380 MODULE_DESCRIPTION("TC35892 GPIO driver");
 381 MODULE_AUTHOR("Hanumath Prasad, Rabin Vincent");