drivers/mfd/twl6030-irq.c

   1 /*
   2  * twl6030-irq.c - TWL6030 irq support
   3  *
   4  * Copyright (C) 2005-2009 Texas Instruments, Inc.
   5  *
   6  * Modifications to defer interrupt handling to a kernel thread:
   7  * Copyright (C) 2006 MontaVista Software, Inc.
   8  *
   9  * Based on tlv320aic23.c:
  10  * Copyright (c) by Kai Svahn <kai.svahn@nokia.com>
  11  *
  12  * Code cleanup and modifications to IRQ handler.
  13  * by syed khasim <x0khasim@ti.com>
  14  *
  15  * TWL6030 specific code and IRQ handling changes by
  16  * Jagadeesh Bhaskar Pakaravoor <j-pakaravoor@ti.com>
  17  * Balaji T K <balajitk@ti.com>
  18  *
  19  * This program is free software; you can redistribute it and/or modify
  20  * it under the terms of the GNU General Public License as published by
  21  * the Free Software Foundation; either version 2 of the License, or
  22  * (at your option) any later version.
  23  *
  24  * This program is distributed in the hope that it will be useful,
  25  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  26  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  27  * GNU General Public License for more details.
  28  *
  29  * You should have received a copy of the GNU General Public License
  30  * along with this program; if not, write to the Free Software
  31  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  32  */
  33
  34 #include <linux/init.h>
  35 #include <linux/export.h>
  36 #include <linux/interrupt.h>
  37 #include <linux/irq.h>
  38 #include <linux/kthread.h>
  39 #include <linux/i2c/twl.h>
  40 #include <linux/platform_device.h>
  41 #include <linux/suspend.h>
  42
  43 #include "twl-core.h"
  44
  45 /*
  46  * TWL6030 (unlike its predecessors, which had two level interrupt handling)
  47  * three interrupt registers INT_STS_A, INT_STS_B and INT_STS_C.
  48  * It exposes status bits saying who has raised an interrupt. There are
  49  * three mask registers that corresponds to these status registers, that
  50  * enables/disables these interrupts.
  51  *
  52  * We set up IRQs starting at a platform-specified base. An interrupt map table,
  53  * specifies mapping between interrupt number and the associated module.
  54  *
  55  */
  56
  57 static int twl6030_interrupt_mapping[24] = {
  58         PWR_INTR_OFFSET,        /* Bit 0        PWRON                   */
  59         PWR_INTR_OFFSET,        /* Bit 1        RPWRON                  */
  60         PWR_INTR_OFFSET,        /* Bit 2        BAT_VLOW                */
  61         RTC_INTR_OFFSET,        /* Bit 3        RTC_ALARM               */
  62         RTC_INTR_OFFSET,        /* Bit 4        RTC_PERIOD              */
  63         HOTDIE_INTR_OFFSET,     /* Bit 5        HOT_DIE                 */
  64         SMPSLDO_INTR_OFFSET,    /* Bit 6        VXXX_SHORT              */
  65         SMPSLDO_INTR_OFFSET,    /* Bit 7        VMMC_SHORT              */
  66
  67         SMPSLDO_INTR_OFFSET,    /* Bit 8        VUSIM_SHORT             */
  68         BATDETECT_INTR_OFFSET,  /* Bit 9        BAT                     */
  69         SIMDETECT_INTR_OFFSET,  /* Bit 10       SIM                     */
  70         MMCDETECT_INTR_OFFSET,  /* Bit 11       MMC                     */
  71         RSV_INTR_OFFSET,        /* Bit 12       Reserved                */
  72         MADC_INTR_OFFSET,       /* Bit 13       GPADC_RT_EOC            */
  73         MADC_INTR_OFFSET,       /* Bit 14       GPADC_SW_EOC            */
  74         GASGAUGE_INTR_OFFSET,   /* Bit 15       CC_AUTOCAL              */
  75
  76         USBOTG_INTR_OFFSET,     /* Bit 16       ID_WKUP                 */
  77         USBOTG_INTR_OFFSET,     /* Bit 17       VBUS_WKUP               */
  78         USBOTG_INTR_OFFSET,     /* Bit 18       ID                      */
  79         USB_PRES_INTR_OFFSET,   /* Bit 19       VBUS                    */
  80         CHARGER_INTR_OFFSET,    /* Bit 20       CHRG_CTRL               */
  81         CHARGERFAULT_INTR_OFFSET,       /* Bit 21       EXT_CHRG        */
  82         CHARGERFAULT_INTR_OFFSET,       /* Bit 22       INT_CHRG        */
  83         RSV_INTR_OFFSET,        /* Bit 23       Reserved                */
  84 };
  85 /*----------------------------------------------------------------------*/
  86
  87 static unsigned twl6030_irq_base;
  88 static int twl_irq;
  89 static bool twl_irq_wake_enabled;
  90
  91 static struct completion irq_event;
  92 static atomic_t twl6030_wakeirqs = ATOMIC_INIT(0);
  93
  94 static int twl6030_irq_pm_notifier(struct notifier_block *notifier,
  95                                    unsigned long pm_event, void *unused)
  96 {
  97         int chained_wakeups;
  98
  99         switch (pm_event) {
 100         case PM_SUSPEND_PREPARE:
 101                 chained_wakeups = atomic_read(&twl6030_wakeirqs);
 102
 103                 if (chained_wakeups && !twl_irq_wake_enabled) {
 104                         if (enable_irq_wake(twl_irq))
 105                                 pr_err("twl6030 IRQ wake enable failed\n");
 106                         else
 107                                 twl_irq_wake_enabled = true;
 108                 } else if (!chained_wakeups && twl_irq_wake_enabled) {
 109                         disable_irq_wake(twl_irq);
 110                         twl_irq_wake_enabled = false;
 111                 }
 112
 113                 disable_irq(twl_irq);
 114                 break;
 115
 116         case PM_POST_SUSPEND:
 117                 enable_irq(twl_irq);
 118                 break;
 119
 120         default:
 121                 break;
 122         }
 123
 124         return NOTIFY_DONE;
 125 }
 126
 127 static struct notifier_block twl6030_irq_pm_notifier_block = {
 128         .notifier_call = twl6030_irq_pm_notifier,
 129 };
 130
 131 /*
 132  * This thread processes interrupts reported by the Primary Interrupt Handler.
 133  */
 134 static int twl6030_irq_thread(void *data)
 135 {
 136         long irq = (long)data;
 137         static unsigned i2c_errors;
 138         static const unsigned max_i2c_errors = 100;
 139         int ret;
 140
 141         current->flags |= PF_NOFREEZE;
 142
 143         while (!kthread_should_stop()) {
 144                 int i;
 145                 union {
 146                 u8 bytes[4];
 147                 u32 int_sts;
 148                 } sts;
 149
 150                 /* Wait for IRQ, then read PIH irq status (also blocking) */
 151                 wait_for_completion_interruptible(&irq_event);
 152
 153                 /* read INT_STS_A, B and C in one shot using a burst read */
 154                 ret = twl_i2c_read(TWL_MODULE_PIH, sts.bytes,
 155                                 REG_INT_STS_A, 3);
 156                 if (ret) {
 157                         pr_warning("twl6030: I2C error %d reading PIH ISR\n",
 158                                         ret);
 159                         if (++i2c_errors >= max_i2c_errors) {
 160                                 printk(KERN_ERR "Maximum I2C error count"
 161                                                 " exceeded.  Terminating %s.\n",
 162                                                 __func__);
 163                                 break;
 164                         }
 165                         complete(&irq_event);
 166                         continue;
 167                 }
 168
 169
 170
 171                 sts.bytes[3] = 0; /* Only 24 bits are valid*/
 172
 173                 /*
 174                  * Since VBUS status bit is not reliable for VBUS disconnect
 175                  * use CHARGER VBUS detection status bit instead.
 176                  */
 177                 if (sts.bytes[2] & 0x10)
 178                         sts.bytes[2] |= 0x08;
 179
 180                 for (i = 0; sts.int_sts; sts.int_sts >>= 1, i++) {
 181                         local_irq_disable();
 182                         if (sts.int_sts & 0x1) {
 183                                 int module_irq = twl6030_irq_base +
 184                                         twl6030_interrupt_mapping[i];
 185                                 generic_handle_irq(module_irq);
 186
 187                         }
 188                 local_irq_enable();
 189                 }
 190
 191                 /*
 192                  * NOTE:
 193                  * Simulation confirms that documentation is wrong w.r.t the
 194                  * interrupt status clear operation. A single *byte* write to
 195                  * any one of STS_A to STS_C register results in all three
 196                  * STS registers being reset. Since it does not matter which
 197                  * value is written, all three registers are cleared on a
 198                  * single byte write, so we just use 0x0 to clear.
 199                  */
 200                 ret = twl_i2c_write_u8(TWL_MODULE_PIH, 0x00, REG_INT_STS_A);
 201                 if (ret)
 202                         pr_warning("twl6030: I2C error in clearing PIH ISR\n");
 203
 204                 enable_irq(irq);
 205         }
 206
 207         return 0;
 208 }
 209
 210 /*
 211  * handle_twl6030_int() is the desc->handle method for the twl6030 interrupt.
 212  * This is a chained interrupt, so there is no desc->action method for it.
 213  * Now we need to query the interrupt controller in the twl6030 to determine
 214  * which module is generating the interrupt request.  However, we can't do i2c
 215  * transactions in interrupt context, so we must defer that work to a kernel
 216  * thread.  All we do here is acknowledge and mask the interrupt and wakeup
 217  * the kernel thread.
 218  */
 219 static irqreturn_t handle_twl6030_pih(int irq, void *devid)
 220 {
 221         disable_irq_nosync(irq);
 222         complete(devid);
 223         return IRQ_HANDLED;
 224 }
 225
 226 /*----------------------------------------------------------------------*/
 227
 228 static inline void activate_irq(int irq)
 229 {
 230 #ifdef CONFIG_ARM
 231         /* ARM requires an extra step to clear IRQ_NOREQUEST, which it
 232          * sets on behalf of every irq_chip.  Also sets IRQ_NOPROBE.
 233          */
 234         set_irq_flags(irq, IRQF_VALID);
 235 #else
 236         /* same effect on other architectures */
 237         irq_set_noprobe(irq);
 238 #endif
 239 }
 240
 241 int twl6030_irq_set_wake(struct irq_data *d, unsigned int on)
 242 {
 243         if (on)
 244                 atomic_inc(&twl6030_wakeirqs);
 245         else
 246                 atomic_dec(&twl6030_wakeirqs);
 247
 248         return 0;
 249 }
 250
 251 /*----------------------------------------------------------------------*/
 252
 253 static unsigned twl6030_irq_next;
 254
 255 /*----------------------------------------------------------------------*/
 256 int twl6030_interrupt_unmask(u8 bit_mask, u8 offset)
 257 {
 258         int ret;
 259         u8 unmask_value;
 260         ret = twl_i2c_read_u8(TWL_MODULE_PIH, &unmask_value,
 261                         REG_INT_STS_A + offset);
 262         unmask_value &= (~(bit_mask));
 263         ret |= twl_i2c_write_u8(TWL_MODULE_PIH, unmask_value,
 264                         REG_INT_STS_A + offset); /* unmask INT_MSK_A/B/C */
 265         return ret;
 266 }
 267 EXPORT_SYMBOL(twl6030_interrupt_unmask);
 268
 269 int twl6030_interrupt_mask(u8 bit_mask, u8 offset)
 270 {
 271         int ret;
 272         u8 mask_value;
 273         ret = twl_i2c_read_u8(TWL_MODULE_PIH, &mask_value,
 274                         REG_INT_STS_A + offset);
 275         mask_value |= (bit_mask);
 276         ret |= twl_i2c_write_u8(TWL_MODULE_PIH, mask_value,
 277                         REG_INT_STS_A + offset); /* mask INT_MSK_A/B/C */
 278         return ret;
 279 }
 280 EXPORT_SYMBOL(twl6030_interrupt_mask);
 281
 282 int twl6030_mmc_card_detect_config(void)
 283 {
 284         int ret;
 285         u8 reg_val = 0;
 286
 287         /* Unmasking the Card detect Interrupt line for MMC1 from Phoenix */
 288         twl6030_interrupt_unmask(TWL6030_MMCDETECT_INT_MASK,
 289                                                 REG_INT_MSK_LINE_B);
 290         twl6030_interrupt_unmask(TWL6030_MMCDETECT_INT_MASK,
 291                                                 REG_INT_MSK_STS_B);
 292         /*
 293          * Initially Configuring MMC_CTRL for receiving interrupts &
 294          * Card status on TWL6030 for MMC1
 295          */
 296         ret = twl_i2c_read_u8(TWL6030_MODULE_ID0, &reg_val, TWL6030_MMCCTRL);
 297         if (ret < 0) {
 298                 pr_err("twl6030: Failed to read MMCCTRL, error %d\n", ret);
 299                 return ret;
 300         }
 301         reg_val &= ~VMMC_AUTO_OFF;
 302         reg_val |= SW_FC;
 303         ret = twl_i2c_write_u8(TWL6030_MODULE_ID0, reg_val, TWL6030_MMCCTRL);
 304         if (ret < 0) {
 305                 pr_err("twl6030: Failed to write MMCCTRL, error %d\n", ret);
 306                 return ret;
 307         }
 308
 309         /* Configuring PullUp-PullDown register */
 310         ret = twl_i2c_read_u8(TWL6030_MODULE_ID0, &reg_val,
 311                                                 TWL6030_CFG_INPUT_PUPD3);
 312         if (ret < 0) {
 313                 pr_err("twl6030: Failed to read CFG_INPUT_PUPD3, error %d\n",
 314                                                                         ret);
 315                 return ret;
 316         }
 317         reg_val &= ~(MMC_PU | MMC_PD);
 318         ret = twl_i2c_write_u8(TWL6030_MODULE_ID0, reg_val,
 319                                                 TWL6030_CFG_INPUT_PUPD3);
 320         if (ret < 0) {
 321                 pr_err("twl6030: Failed to write CFG_INPUT_PUPD3, error %d\n",
 322                                                                         ret);
 323                 return ret;
 324         }
 325         return 0;
 326 }
 327 EXPORT_SYMBOL(twl6030_mmc_card_detect_config);
 328
 329 int twl6030_mmc_card_detect(struct device *dev, int slot)
 330 {
 331         int ret = -EIO;
 332         u8 read_reg = 0;
 333         struct platform_device *pdev = to_platform_device(dev);
 334
 335         if (pdev->id) {
 336                 /* TWL6030 provide's Card detect support for
 337                  * only MMC1 controller.
 338                  */
 339                 pr_err("Unknown MMC controller %d in %s\n", pdev->id, __func__);
 340                 return ret;
 341         }
 342         /*
 343          * BIT0 of MMC_CTRL on TWL6030 provides card status for MMC1
 344          * 0 - Card not present ,1 - Card present
 345          */
 346         ret = twl_i2c_read_u8(TWL6030_MODULE_ID0, &read_reg,
 347                                                 TWL6030_MMCCTRL);
 348         if (ret >= 0)
 349                 ret = read_reg & STS_MMC;
 350         return ret;
 351 }
 352 EXPORT_SYMBOL(twl6030_mmc_card_detect);
 353
 354 int twl6030_init_irq(int irq_num, unsigned irq_base, unsigned irq_end)
 355 {
 356
 357         int     status = 0;
 358         int     i;
 359         struct task_struct      *task;
 360         int ret;
 361         u8 mask[4];
 362
 363         static struct irq_chip  twl6030_irq_chip;
 364         mask[1] = 0xFF;
 365         mask[2] = 0xFF;
 366         mask[3] = 0xFF;
 367         ret = twl_i2c_write(TWL_MODULE_PIH, &mask[0],
 368                         REG_INT_MSK_LINE_A, 3); /* MASK ALL INT LINES */
 369         ret = twl_i2c_write(TWL_MODULE_PIH, &mask[0],
 370                         REG_INT_MSK_STS_A, 3); /* MASK ALL INT STS */
 371         ret = twl_i2c_write(TWL_MODULE_PIH, &mask[0],
 372                         REG_INT_STS_A, 3); /* clear INT_STS_A,B,C */
 373
 374         twl6030_irq_base = irq_base;
 375
 376         /* install an irq handler for each of the modules;
 377          * clone dummy irq_chip since PIH can't *do* anything
 378          */
 379         twl6030_irq_chip = dummy_irq_chip;
 380         twl6030_irq_chip.name = "twl6030";
 381         twl6030_irq_chip.irq_set_type = NULL;
 382         twl6030_irq_chip.irq_set_wake = twl6030_irq_set_wake;
 383
 384         for (i = irq_base; i < irq_end; i++) {
 385                 irq_set_chip_and_handler(i, &twl6030_irq_chip,
 386                                          handle_simple_irq);
 387                 irq_set_chip_data(i, (void *)irq_num);
 388                 activate_irq(i);
 389         }
 390
 391         twl6030_irq_next = i;
 392         pr_info("twl6030: %s (irq %d) chaining IRQs %d..%d\n", "PIH",
 393                         irq_num, irq_base, twl6030_irq_next - 1);
 394
 395         /* install an irq handler to demultiplex the TWL6030 interrupt */
 396         init_completion(&irq_event);
 397
 398         status = request_irq(irq_num, handle_twl6030_pih, 0,
 399                                 "TWL6030-PIH", &irq_event);
 400         if (status < 0) {
 401                 pr_err("twl6030: could not claim irq%d: %d\n", irq_num, status);
 402                 goto fail_irq;
 403         }
 404
 405         task = kthread_run(twl6030_irq_thread, (void *)irq_num, "twl6030-irq");
 406         if (IS_ERR(task)) {
 407                 pr_err("twl6030: could not create irq %d thread!\n", irq_num);
 408                 status = PTR_ERR(task);
 409                 goto fail_kthread;
 410         }
 411
 412         twl_irq = irq_num;
 413         register_pm_notifier(&twl6030_irq_pm_notifier_block);
 414         return status;
 415
 416 fail_kthread:
 417         free_irq(irq_num, &irq_event);
 418
 419 fail_irq:
 420         for (i = irq_base; i < irq_end; i++)
 421                 irq_set_chip_and_handler(i, NULL, NULL);
 422         return status;
 423 }
 424
 425 int twl6030_exit_irq(void)
 426 {
 427         unregister_pm_notifier(&twl6030_irq_pm_notifier_block);
 428
 429         if (twl6030_irq_base) {
 430                 pr_err("twl6030: can't yet clean up IRQs?\n");
 431                 return -ENOSYS;
 432         }
 433         return 0;
 434 }
 435