drivers/mfd/htc-egpio.c

   1 /*
   2  * Support for the GPIO/IRQ expander chips present on several HTC phones.
   3  * These are implemented in CPLD chips present on the board.
   4  *
   5  * Copyright (c) 2007 Kevin O'Connor <kevin@koconnor.net>
   6  * Copyright (c) 2007 Philipp Zabel <philipp.zabel@gmail.com>
   7  *
   8  * This file may be distributed under the terms of the GNU GPL license.
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/errno.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/irq.h>
  15 #include <linux/io.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/slab.h>
  19 #include <linux/module.h>
  20 #include <linux/mfd/htc-egpio.h>
  21
  22 struct egpio_chip {
  23         int              reg_start;
  24         int              cached_values;
  25         unsigned long    is_out;
  26         struct device    *dev;
  27         struct gpio_chip chip;
  28 };
  29
  30 struct egpio_info {
  31         spinlock_t        lock;
  32
  33         /* iomem info */
  34         void __iomem      *base_addr;
  35         int               bus_shift;    /* byte shift */
  36         int               reg_shift;    /* bit shift */
  37         int               reg_mask;
  38
  39         /* irq info */
  40         int               ack_register;
  41         int               ack_write;
  42         u16               irqs_enabled;
  43         uint              irq_start;
  44         int               nirqs;
  45         uint              chained_irq;
  46
  47         /* egpio info */
  48         struct egpio_chip *chip;
  49         int               nchips;
  50 };
  51
  52 static inline void egpio_writew(u16 value, struct egpio_info *ei, int reg)
  53 {
  54         writew(value, ei->base_addr + (reg << ei->bus_shift));
  55 }
  56
  57 static inline u16 egpio_readw(struct egpio_info *ei, int reg)
  58 {
  59         return readw(ei->base_addr + (reg << ei->bus_shift));
  60 }
  61
  62 /*
  63  * IRQs
  64  */
  65
  66 static inline void ack_irqs(struct egpio_info *ei)
  67 {
  68         egpio_writew(ei->ack_write, ei, ei->ack_register);
  69         pr_debug("EGPIO ack - write %x to base+%x\n",
  70                         ei->ack_write, ei->ack_register << ei->bus_shift);
  71 }
  72
  73 static void egpio_ack(unsigned int irq)
  74 {
  75 }
  76
  77 /* There does not appear to be a way to proactively mask interrupts
  78  * on the egpio chip itself.  So, we simply ignore interrupts that
  79  * aren't desired. */
  80 static void egpio_mask(unsigned int irq)
  81 {
  82         struct egpio_info *ei = get_irq_chip_data(irq);
  83         ei->irqs_enabled &= ~(1 << (irq - ei->irq_start));
  84         pr_debug("EGPIO mask %d %04x\n", irq, ei->irqs_enabled);
  85 }
  86 static void egpio_unmask(unsigned int irq)
  87 {
  88         struct egpio_info *ei = get_irq_chip_data(irq);
  89         ei->irqs_enabled |= 1 << (irq - ei->irq_start);
  90         pr_debug("EGPIO unmask %d %04x\n", irq, ei->irqs_enabled);
  91 }
  92
  93 static struct irq_chip egpio_muxed_chip = {
  94         .name   = "htc-egpio",
  95         .ack    = egpio_ack,
  96         .mask   = egpio_mask,
  97         .unmask = egpio_unmask,
  98 };
  99
 100 static void egpio_handler(unsigned int irq, struct irq_desc *desc)
 101 {
 102         struct egpio_info *ei = get_irq_data(irq);
 103         int irqpin;
 104
 105         /* Read current pins. */
 106         unsigned long readval = egpio_readw(ei, ei->ack_register);
 107         pr_debug("IRQ reg: %x\n", (unsigned int)readval);
 108         /* Ack/unmask interrupts. */
 109         ack_irqs(ei);
 110         /* Process all set pins. */
 111         readval &= ei->irqs_enabled;
 112         for_each_set_bit(irqpin, &readval, ei->nirqs) {
 113                 /* Run irq handler */
 114                 pr_debug("got IRQ %d\n", irqpin);
 115                 irq = ei->irq_start + irqpin;
 116                 desc = irq_to_desc(irq);
 117                 desc->handle_irq(irq, desc);
 118         }
 119 }
 120
 121 int htc_egpio_get_wakeup_irq(struct device *dev)
 122 {
 123         struct egpio_info *ei = dev_get_drvdata(dev);
 124
 125         /* Read current pins. */
 126         u16 readval = egpio_readw(ei, ei->ack_register);
 127         /* Ack/unmask interrupts. */
 128         ack_irqs(ei);
 129         /* Return first set pin. */
 130         readval &= ei->irqs_enabled;
 131         return ei->irq_start + ffs(readval) - 1;
 132 }
 133 EXPORT_SYMBOL(htc_egpio_get_wakeup_irq);
 134
 135 static inline int egpio_pos(struct egpio_info *ei, int bit)
 136 {
 137         return bit >> ei->reg_shift;
 138 }
 139
 140 static inline int egpio_bit(struct egpio_info *ei, int bit)
 141 {
 142         return 1 << (bit & ((1 << ei->reg_shift)-1));
 143 }
 144
 145 /*
 146  * Input pins
 147  */
 148
 149 static int egpio_get(struct gpio_chip *chip, unsigned offset)
 150 {
 151         struct egpio_chip *egpio;
 152         struct egpio_info *ei;
 153         unsigned           bit;
 154         int                reg;
 155         int                value;
 156
 157         pr_debug("egpio_get_value(%d)\n", chip->base + offset);
 158
 159         egpio = container_of(chip, struct egpio_chip, chip);
 160         ei    = dev_get_drvdata(egpio->dev);
 161         bit   = egpio_bit(ei, offset);
 162         reg   = egpio->reg_start + egpio_pos(ei, offset);
 163
 164         value = egpio_readw(ei, reg);
 165         pr_debug("readw(%p + %x) = %x\n",
 166                         ei->base_addr, reg << ei->bus_shift, value);
 167         return value & bit;
 168 }
 169
 170 static int egpio_direction_input(struct gpio_chip *chip, unsigned offset)
 171 {
 172         struct egpio_chip *egpio;
 173
 174         egpio = container_of(chip, struct egpio_chip, chip);
 175         return test_bit(offset, &egpio->is_out) ? -EINVAL : 0;
 176 }
 177
 178
 179 /*
 180  * Output pins
 181  */
 182
 183 static void egpio_set(struct gpio_chip *chip, unsigned offset, int value)
 184 {
 185         unsigned long     flag;
 186         struct egpio_chip *egpio;
 187         struct egpio_info *ei;
 188         unsigned          bit;
 189         int               pos;
 190         int               reg;
 191         int               shift;
 192
 193         pr_debug("egpio_set(%s, %d(%d), %d)\n",
 194                         chip->label, offset, offset+chip->base, value);
 195
 196         egpio = container_of(chip, struct egpio_chip, chip);
 197         ei    = dev_get_drvdata(egpio->dev);
 198         bit   = egpio_bit(ei, offset);
 199         pos   = egpio_pos(ei, offset);
 200         reg   = egpio->reg_start + pos;
 201         shift = pos << ei->reg_shift;
 202
 203         pr_debug("egpio %s: reg %d = 0x%04x\n", value ? "set" : "clear",
 204                         reg, (egpio->cached_values >> shift) & ei->reg_mask);
 205
 206         spin_lock_irqsave(&ei->lock, flag);
 207         if (value)
 208                 egpio->cached_values |= (1 << offset);
 209         else
 210                 egpio->cached_values &= ~(1 << offset);
 211         egpio_writew((egpio->cached_values >> shift) & ei->reg_mask, ei, reg);
 212         spin_unlock_irqrestore(&ei->lock, flag);
 213 }
 214
 215 static int egpio_direction_output(struct gpio_chip *chip,
 216                                         unsigned offset, int value)
 217 {
 218         struct egpio_chip *egpio;
 219
 220         egpio = container_of(chip, struct egpio_chip, chip);
 221         if (test_bit(offset, &egpio->is_out)) {
 222                 egpio_set(chip, offset, value);
 223                 return 0;
 224         } else {
 225                 return -EINVAL;
 226         }
 227 }
 228
 229 static void egpio_write_cache(struct egpio_info *ei)
 230 {
 231         int               i;
 232         struct egpio_chip *egpio;
 233         int               shift;
 234
 235         for (i = 0; i < ei->nchips; i++) {
 236                 egpio = &(ei->chip[i]);
 237                 if (!egpio->is_out)
 238                         continue;
 239
 240                 for (shift = 0; shift < egpio->chip.ngpio;
 241                                 shift += (1<<ei->reg_shift)) {
 242
 243                         int reg = egpio->reg_start + egpio_pos(ei, shift);
 244
 245                         if (!((egpio->is_out >> shift) & ei->reg_mask))
 246                                 continue;
 247
 248                         pr_debug("EGPIO: setting %x to %x, was %x\n", reg,
 249                                 (egpio->cached_values >> shift) & ei->reg_mask,
 250                                 egpio_readw(ei, reg));
 251
 252                         egpio_writew((egpio->cached_values >> shift)
 253                                         & ei->reg_mask, ei, reg);
 254                 }
 255         }
 256 }
 257
 258
 259 /*
 260  * Setup
 261  */
 262
 263 static int __init egpio_probe(struct platform_device *pdev)
 264 {
 265         struct htc_egpio_platform_data *pdata = pdev->dev.platform_data;
 266         struct resource   *res;
 267         struct egpio_info *ei;
 268         struct gpio_chip  *chip;
 269         unsigned int      irq, irq_end;
 270         int               i;
 271         int               ret;
 272
 273         /* Initialize ei data structure. */
 274         ei = kzalloc(sizeof(*ei), GFP_KERNEL);
 275         if (!ei)
 276                 return -ENOMEM;
 277
 278         spin_lock_init(&ei->lock);
 279
 280         /* Find chained irq */
 281         ret = -EINVAL;
 282         res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 283         if (res)
 284                 ei->chained_irq = res->start;
 285
 286         /* Map egpio chip into virtual address space. */
 287         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 288         if (!res)
 289                 goto fail;
 290         ei->base_addr = ioremap_nocache(res->start, resource_size(res));
 291         if (!ei->base_addr)
 292                 goto fail;
 293         pr_debug("EGPIO phys=%08x virt=%p\n", (u32)res->start, ei->base_addr);
 294
 295         if ((pdata->bus_width != 16) && (pdata->bus_width != 32))
 296                 goto fail;
 297         ei->bus_shift = fls(pdata->bus_width - 1) - 3;
 298         pr_debug("bus_shift = %d\n", ei->bus_shift);
 299
 300         if ((pdata->reg_width != 8) && (pdata->reg_width != 16))
 301                 goto fail;
 302         ei->reg_shift = fls(pdata->reg_width - 1);
 303         pr_debug("reg_shift = %d\n", ei->reg_shift);
 304
 305         ei->reg_mask = (1 << pdata->reg_width) - 1;
 306
 307         platform_set_drvdata(pdev, ei);
 308
 309         ei->nchips = pdata->num_chips;
 310         ei->chip = kzalloc(sizeof(struct egpio_chip) * ei->nchips, GFP_KERNEL);
 311         if (!ei->chip) {
 312                 ret = -ENOMEM;
 313                 goto fail;
 314         }
 315         for (i = 0; i < ei->nchips; i++) {
 316                 ei->chip[i].reg_start = pdata->chip[i].reg_start;
 317                 ei->chip[i].cached_values = pdata->chip[i].initial_values;
 318                 ei->chip[i].is_out = pdata->chip[i].direction;
 319                 ei->chip[i].dev = &(pdev->dev);
 320                 chip = &(ei->chip[i].chip);
 321                 chip->label           = "htc-egpio";
 322                 chip->dev             = &pdev->dev;
 323                 chip->owner           = THIS_MODULE;
 324                 chip->get             = egpio_get;
 325                 chip->set             = egpio_set;
 326                 chip->direction_input = egpio_direction_input;
 327                 chip->direction_output = egpio_direction_output;
 328                 chip->base            = pdata->chip[i].gpio_base;
 329                 chip->ngpio           = pdata->chip[i].num_gpios;
 330
 331                 gpiochip_add(chip);
 332         }
 333
 334         /* Set initial pin values */
 335         egpio_write_cache(ei);
 336
 337         ei->irq_start = pdata->irq_base;
 338         ei->nirqs = pdata->num_irqs;
 339         ei->ack_register = pdata->ack_register;
 340
 341         if (ei->chained_irq) {
 342                 /* Setup irq handlers */
 343                 ei->ack_write = 0xFFFF;
 344                 if (pdata->invert_acks)
 345                         ei->ack_write = 0;
 346                 irq_end = ei->irq_start + ei->nirqs;
 347                 for (irq = ei->irq_start; irq < irq_end; irq++) {
 348                         set_irq_chip(irq, &egpio_muxed_chip);
 349                         set_irq_chip_data(irq, ei);
 350                         set_irq_handler(irq, handle_simple_irq);
 351                         set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
 352                 }
 353                 set_irq_type(ei->chained_irq, IRQ_TYPE_EDGE_RISING);
 354                 set_irq_data(ei->chained_irq, ei);
 355                 set_irq_chained_handler(ei->chained_irq, egpio_handler);
 356                 ack_irqs(ei);
 357
 358                 device_init_wakeup(&pdev->dev, 1);
 359         }
 360
 361         return 0;
 362
 363 fail:
 364         printk(KERN_ERR "EGPIO failed to setup\n");
 365         kfree(ei);
 366         return ret;
 367 }
 368
 369 static int __exit egpio_remove(struct platform_device *pdev)
 370 {
 371         struct egpio_info *ei = platform_get_drvdata(pdev);
 372         unsigned int      irq, irq_end;
 373
 374         if (ei->chained_irq) {
 375                 irq_end = ei->irq_start + ei->nirqs;
 376                 for (irq = ei->irq_start; irq < irq_end; irq++) {
 377                         set_irq_chip(irq, NULL);
 378                         set_irq_handler(irq, NULL);
 379                         set_irq_flags(irq, 0);
 380                 }
 381                 set_irq_chained_handler(ei->chained_irq, NULL);
 382                 device_init_wakeup(&pdev->dev, 0);
 383         }
 384         iounmap(ei->base_addr);
 385         kfree(ei->chip);
 386         kfree(ei);
 387
 388         return 0;
 389 }
 390
 391 #ifdef CONFIG_PM
 392 static int egpio_suspend(struct platform_device *pdev, pm_message_t state)
 393 {
 394         struct egpio_info *ei = platform_get_drvdata(pdev);
 395
 396         if (ei->chained_irq && device_may_wakeup(&pdev->dev))
 397                 enable_irq_wake(ei->chained_irq);
 398         return 0;
 399 }
 400
 401 static int egpio_resume(struct platform_device *pdev)
 402 {
 403         struct egpio_info *ei = platform_get_drvdata(pdev);
 404
 405         if (ei->chained_irq && device_may_wakeup(&pdev->dev))
 406                 disable_irq_wake(ei->chained_irq);
 407
 408         /* Update registers from the cache, in case
 409            the CPLD was powered off during suspend */
 410         egpio_write_cache(ei);
 411         return 0;
 412 }
 413 #else
 414 #define egpio_suspend NULL
 415 #define egpio_resume NULL
 416 #endif
 417
 418
 419 static struct platform_driver egpio_driver = {
 420         .driver = {
 421                 .name = "htc-egpio",
 422         },
 423         .remove       = __exit_p(egpio_remove),
 424         .suspend      = egpio_suspend,
 425         .resume       = egpio_resume,
 426 };
 427
 428 static int __init egpio_init(void)
 429 {
 430         return platform_driver_probe(&egpio_driver, egpio_probe);
 431 }
 432
 433 static void __exit egpio_exit(void)
 434 {
 435         platform_driver_unregister(&egpio_driver);
 436 }
 437
 438 /* start early for dependencies */
 439 subsys_initcall(egpio_init);
 440 module_exit(egpio_exit)
 441
 442 MODULE_LICENSE("GPL");
 443 MODULE_AUTHOR("Kevin O'Connor <kevin@koconnor.net>");