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