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
  40 /*
  41  * TWL6030 (unlike its predecessors, which had two level interrupt handling)
  42  * three interrupt registers INT_STS_A, INT_STS_B and INT_STS_C.
  43  * It exposes status bits saying who has raised an interrupt. There are
  44  * three mask registers that corresponds to these status registers, that
  45  * enables/disables these interrupts.
  46  *
  47  * We set up IRQs starting at a platform-specified base. An interrupt map table,
  48  * specifies mapping between interrupt number and the associated module.
  49  *
  50  */
  51
  52 static int twl6030_interrupt_mapping[24] = {
  53         PWR_INTR_OFFSET,        /* Bit 0        PWRON                   */
  54         PWR_INTR_OFFSET,        /* Bit 1        RPWRON                  */
  55         PWR_INTR_OFFSET,        /* Bit 2        BAT_VLOW                */
  56         RTC_INTR_OFFSET,        /* Bit 3        RTC_ALARM               */
  57         RTC_INTR_OFFSET,        /* Bit 4        RTC_PERIOD              */
  58         HOTDIE_INTR_OFFSET,     /* Bit 5        HOT_DIE                 */
  59         SMPSLDO_INTR_OFFSET,    /* Bit 6        VXXX_SHORT              */
  60         SMPSLDO_INTR_OFFSET,    /* Bit 7        VMMC_SHORT              */
  61
  62         SMPSLDO_INTR_OFFSET,    /* Bit 8        VUSIM_SHORT             */
  63         BATDETECT_INTR_OFFSET,  /* Bit 9        BAT                     */
  64         SIMDETECT_INTR_OFFSET,  /* Bit 10       SIM                     */
  65         MMCDETECT_INTR_OFFSET,  /* Bit 11       MMC                     */
  66         RSV_INTR_OFFSET,        /* Bit 12       Reserved                */
  67         MADC_INTR_OFFSET,       /* Bit 13       GPADC_RT_EOC            */
  68         MADC_INTR_OFFSET,       /* Bit 14       GPADC_SW_EOC            */
  69         GASGAUGE_INTR_OFFSET,   /* Bit 15       CC_AUTOCAL              */
  70
  71         USBOTG_INTR_OFFSET,     /* Bit 16       ID_WKUP                 */
  72         USBOTG_INTR_OFFSET,     /* Bit 17       VBUS_WKUP               */
  73         USBOTG_INTR_OFFSET,     /* Bit 18       ID                      */
  74         USBOTG_INTR_OFFSET,     /* Bit 19       VBUS                    */
  75         CHARGER_INTR_OFFSET,    /* Bit 20       CHRG_CTRL               */
  76         CHARGER_INTR_OFFSET,    /* Bit 21       EXT_CHRG                */
  77         CHARGER_INTR_OFFSET,    /* Bit 22       INT_CHRG                */
  78         RSV_INTR_OFFSET,        /* Bit 23       Reserved                */
  79 };
  80 /*----------------------------------------------------------------------*/
  81
  82 static unsigned twl6030_irq_base;
  83
  84 static struct completion irq_event;
  85
  86 /*
  87  * This thread processes interrupts reported by the Primary Interrupt Handler.
  88  */
  89 static int twl6030_irq_thread(void *data)
  90 {
  91         long irq = (long)data;
  92         static unsigned i2c_errors;
  93         static const unsigned max_i2c_errors = 100;
  94         int ret;
  95
  96         current->flags |= PF_NOFREEZE;
  97
  98         while (!kthread_should_stop()) {
  99                 int i;
 100                 union {
 101                 u8 bytes[4];
 102                 u32 int_sts;
 103                 } sts;
 104
 105                 /* Wait for IRQ, then read PIH irq status (also blocking) */
 106                 wait_for_completion_interruptible(&irq_event);
 107
 108                 /* read INT_STS_A, B and C in one shot using a burst read */
 109                 ret = twl_i2c_read(TWL_MODULE_PIH, sts.bytes,
 110                                 REG_INT_STS_A, 3);
 111                 if (ret) {
 112                         pr_warning("twl6030: I2C error %d reading PIH ISR\n",
 113                                         ret);
 114                         if (++i2c_errors >= max_i2c_errors) {
 115                                 printk(KERN_ERR "Maximum I2C error count"
 116                                                 " exceeded.  Terminating %s.\n",
 117                                                 __func__);
 118                                 break;
 119                         }
 120                         complete(&irq_event);
 121                         continue;
 122                 }
 123
 124
 125
 126                 sts.bytes[3] = 0; /* Only 24 bits are valid*/
 127
 128                 for (i = 0; sts.int_sts; sts.int_sts >>= 1, i++) {
 129                         local_irq_disable();
 130                         if (sts.int_sts & 0x1) {
 131                                 int module_irq = twl6030_irq_base +
 132                                         twl6030_interrupt_mapping[i];
 133                                 struct irq_desc *d = irq_to_desc(module_irq);
 134
 135                                 if (!d) {
 136                                         pr_err("twl6030: Invalid SIH IRQ: %d\n",
 137                                                module_irq);
 138                                         return -EINVAL;
 139                                 }
 140
 141                                 /* These can't be masked ... always warn
 142                                  * if we get any surprises.
 143                                  */
 144                                 if (d->status & IRQ_DISABLED)
 145                                         note_interrupt(module_irq, d,
 146                                                         IRQ_NONE);
 147                                 else
 148                                         d->handle_irq(module_irq, d);
 149
 150                         }
 151                 local_irq_enable();
 152                 }
 153                 ret = twl_i2c_write(TWL_MODULE_PIH, sts.bytes,
 154                                 REG_INT_STS_A, 3); /* clear INT_STS_A */
 155                 if (ret)
 156                         pr_warning("twl6030: I2C error in clearing PIH ISR\n");
 157
 158                 enable_irq(irq);
 159         }
 160
 161         return 0;
 162 }
 163
 164 /*
 165  * handle_twl6030_int() is the desc->handle method for the twl6030 interrupt.
 166  * This is a chained interrupt, so there is no desc->action method for it.
 167  * Now we need to query the interrupt controller in the twl6030 to determine
 168  * which module is generating the interrupt request.  However, we can't do i2c
 169  * transactions in interrupt context, so we must defer that work to a kernel
 170  * thread.  All we do here is acknowledge and mask the interrupt and wakeup
 171  * the kernel thread.
 172  */
 173 static irqreturn_t handle_twl6030_pih(int irq, void *devid)
 174 {
 175         disable_irq_nosync(irq);
 176         complete(devid);
 177         return IRQ_HANDLED;
 178 }
 179
 180 /*----------------------------------------------------------------------*/
 181
 182 static inline void activate_irq(int irq)
 183 {
 184 #ifdef CONFIG_ARM
 185         /* ARM requires an extra step to clear IRQ_NOREQUEST, which it
 186          * sets on behalf of every irq_chip.  Also sets IRQ_NOPROBE.
 187          */
 188         set_irq_flags(irq, IRQF_VALID);
 189 #else
 190         /* same effect on other architectures */
 191         set_irq_noprobe(irq);
 192 #endif
 193 }
 194
 195 /*----------------------------------------------------------------------*/
 196
 197 static unsigned twl6030_irq_next;
 198
 199 /*----------------------------------------------------------------------*/
 200 int twl6030_interrupt_unmask(u8 bit_mask, u8 offset)
 201 {
 202         int ret;
 203         u8 unmask_value;
 204         ret = twl_i2c_read_u8(TWL_MODULE_PIH, &unmask_value,
 205                         REG_INT_STS_A + offset);
 206         unmask_value &= (~(bit_mask));
 207         ret |= twl_i2c_write_u8(TWL_MODULE_PIH, unmask_value,
 208                         REG_INT_STS_A + offset); /* unmask INT_MSK_A/B/C */
 209         return ret;
 210 }
 211 EXPORT_SYMBOL(twl6030_interrupt_unmask);
 212
 213 int twl6030_interrupt_mask(u8 bit_mask, u8 offset)
 214 {
 215         int ret;
 216         u8 mask_value;
 217         ret = twl_i2c_read_u8(TWL_MODULE_PIH, &mask_value,
 218                         REG_INT_STS_A + offset);
 219         mask_value |= (bit_mask);
 220         ret |= twl_i2c_write_u8(TWL_MODULE_PIH, mask_value,
 221                         REG_INT_STS_A + offset); /* mask INT_MSK_A/B/C */
 222         return ret;
 223 }
 224 EXPORT_SYMBOL(twl6030_interrupt_mask);
 225
 226 int twl6030_init_irq(int irq_num, unsigned irq_base, unsigned irq_end)
 227 {
 228
 229         int     status = 0;
 230         int     i;
 231         struct task_struct      *task;
 232         int ret;
 233         u8 mask[4];
 234
 235         static struct irq_chip  twl6030_irq_chip;
 236         mask[1] = 0xFF;
 237         mask[2] = 0xFF;
 238         mask[3] = 0xFF;
 239         ret = twl_i2c_write(TWL_MODULE_PIH, &mask[0],
 240                         REG_INT_MSK_LINE_A, 3); /* MASK ALL INT LINES */
 241         ret = twl_i2c_write(TWL_MODULE_PIH, &mask[0],
 242                         REG_INT_MSK_STS_A, 3); /* MASK ALL INT STS */
 243         ret = twl_i2c_write(TWL_MODULE_PIH, &mask[0],
 244                         REG_INT_STS_A, 3); /* clear INT_STS_A,B,C */
 245
 246         twl6030_irq_base = irq_base;
 247
 248         /* install an irq handler for each of the modules;
 249          * clone dummy irq_chip since PIH can't *do* anything
 250          */
 251         twl6030_irq_chip = dummy_irq_chip;
 252         twl6030_irq_chip.name = "twl6030";
 253         twl6030_irq_chip.set_type = NULL;
 254
 255         for (i = irq_base; i < irq_end; i++) {
 256                 set_irq_chip_and_handler(i, &twl6030_irq_chip,
 257                                 handle_simple_irq);
 258                 activate_irq(i);
 259         }
 260
 261         twl6030_irq_next = i;
 262         pr_info("twl6030: %s (irq %d) chaining IRQs %d..%d\n", "PIH",
 263                         irq_num, irq_base, twl6030_irq_next - 1);
 264
 265         /* install an irq handler to demultiplex the TWL6030 interrupt */
 266         init_completion(&irq_event);
 267         task = kthread_run(twl6030_irq_thread, (void *)irq_num, "twl6030-irq");
 268         if (IS_ERR(task)) {
 269                 pr_err("twl6030: could not create irq %d thread!\n", irq_num);
 270                 status = PTR_ERR(task);
 271                 goto fail_kthread;
 272         }
 273
 274         status = request_irq(irq_num, handle_twl6030_pih, IRQF_DISABLED,
 275                                 "TWL6030-PIH", &irq_event);
 276         if (status < 0) {
 277                 pr_err("twl6030: could not claim irq%d: %d\n", irq_num, status);
 278                 goto fail_irq;
 279         }
 280         return status;
 281 fail_irq:
 282         free_irq(irq_num, &irq_event);
 283
 284 fail_kthread:
 285         for (i = irq_base; i < irq_end; i++)
 286                 set_irq_chip_and_handler(i, NULL, NULL);
 287         return status;
 288 }
 289
 290 int twl6030_exit_irq(void)
 291 {
 292
 293         if (twl6030_irq_base) {
 294                 pr_err("twl6030: can't yet clean up IRQs?\n");
 295                 return -ENOSYS;
 296         }
 297         return 0;
 298 }
 299