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