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