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
  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
  88 static struct completion irq_event;
  89
  90 /*
  91  * This thread processes interrupts reported by the Primary Interrupt Handler.
  92  */
  93 static int twl6030_irq_thread(void *data)
  94 {
  95         long irq = (long)data;
  96         static unsigned i2c_errors;
  97         static const unsigned max_i2c_errors = 100;
  98         int ret;
  99
 100         current->flags |= PF_NOFREEZE;
 101
 102         while (!kthread_should_stop()) {
 103                 int i;
 104                 union {
 105                 u8 bytes[4];
 106                 u32 int_sts;
 107                 } sts;
 108
 109                 /* Wait for IRQ, then read PIH irq status (also blocking) */
 110                 wait_for_completion_interruptible(&irq_event);
 111
 112                 /* read INT_STS_A, B and C in one shot using a burst read */
 113                 ret = twl_i2c_read(TWL_MODULE_PIH, sts.bytes,
 114                                 REG_INT_STS_A, 3);
 115                 if (ret) {
 116                         pr_warning("twl6030: I2C error %d reading PIH ISR\n",
 117                                         ret);
 118                         if (++i2c_errors >= max_i2c_errors) {
 119                                 printk(KERN_ERR "Maximum I2C error count"
 120                                                 " exceeded.  Terminating %s.\n",
 121                                                 __func__);
 122                                 break;
 123                         }
 124                         complete(&irq_event);
 125                         continue;
 126                 }
 127
 128
 129
 130                 sts.bytes[3] = 0; /* Only 24 bits are valid*/
 131
 132                 /*
 133                  * Since VBUS status bit is not reliable for VBUS disconnect
 134                  * use CHARGER VBUS detection status bit instead.
 135                  */
 136                 if (sts.bytes[2] & 0x10)
 137                         sts.bytes[2] |= 0x08;
 138
 139                 for (i = 0; sts.int_sts; sts.int_sts >>= 1, i++) {
 140                         local_irq_disable();
 141                         if (sts.int_sts & 0x1) {
 142                                 int module_irq = twl6030_irq_base +
 143                                         twl6030_interrupt_mapping[i];
 144                                 generic_handle_irq(module_irq);
 145
 146                         }
 147                 local_irq_enable();
 148                 }
 149                 ret = twl_i2c_write(TWL_MODULE_PIH, sts.bytes,
 150                                 REG_INT_STS_A, 3); /* clear INT_STS_A */
 151                 if (ret)
 152                         pr_warning("twl6030: I2C error in clearing PIH ISR\n");
 153
 154                 enable_irq(irq);
 155         }
 156
 157         return 0;
 158 }
 159
 160 /*
 161  * handle_twl6030_int() is the desc->handle method for the twl6030 interrupt.
 162  * This is a chained interrupt, so there is no desc->action method for it.
 163  * Now we need to query the interrupt controller in the twl6030 to determine
 164  * which module is generating the interrupt request.  However, we can't do i2c
 165  * transactions in interrupt context, so we must defer that work to a kernel
 166  * thread.  All we do here is acknowledge and mask the interrupt and wakeup
 167  * the kernel thread.
 168  */
 169 static irqreturn_t handle_twl6030_pih(int irq, void *devid)
 170 {
 171         disable_irq_nosync(irq);
 172         complete(devid);
 173         return IRQ_HANDLED;
 174 }
 175
 176 /*----------------------------------------------------------------------*/
 177
 178 static inline void activate_irq(int irq)
 179 {
 180 #ifdef CONFIG_ARM
 181         /* ARM requires an extra step to clear IRQ_NOREQUEST, which it
 182          * sets on behalf of every irq_chip.  Also sets IRQ_NOPROBE.
 183          */
 184         set_irq_flags(irq, IRQF_VALID);
 185 #else
 186         /* same effect on other architectures */
 187         irq_set_noprobe(irq);
 188 #endif
 189 }
 190
 191 /*----------------------------------------------------------------------*/
 192
 193 static unsigned twl6030_irq_next;
 194
 195 /*----------------------------------------------------------------------*/
 196 int twl6030_interrupt_unmask(u8 bit_mask, u8 offset)
 197 {
 198         int ret;
 199         u8 unmask_value;
 200         ret = twl_i2c_read_u8(TWL_MODULE_PIH, &unmask_value,
 201                         REG_INT_STS_A + offset);
 202         unmask_value &= (~(bit_mask));
 203         ret |= twl_i2c_write_u8(TWL_MODULE_PIH, unmask_value,
 204                         REG_INT_STS_A + offset); /* unmask INT_MSK_A/B/C */
 205         return ret;
 206 }
 207 EXPORT_SYMBOL(twl6030_interrupt_unmask);
 208
 209 int twl6030_interrupt_mask(u8 bit_mask, u8 offset)
 210 {
 211         int ret;
 212         u8 mask_value;
 213         ret = twl_i2c_read_u8(TWL_MODULE_PIH, &mask_value,
 214                         REG_INT_STS_A + offset);
 215         mask_value |= (bit_mask);
 216         ret |= twl_i2c_write_u8(TWL_MODULE_PIH, mask_value,
 217                         REG_INT_STS_A + offset); /* mask INT_MSK_A/B/C */
 218         return ret;
 219 }
 220 EXPORT_SYMBOL(twl6030_interrupt_mask);
 221
 222 int twl6030_mmc_card_detect_config(void)
 223 {
 224         int ret;
 225         u8 reg_val = 0;
 226
 227         /* Unmasking the Card detect Interrupt line for MMC1 from Phoenix */
 228         twl6030_interrupt_unmask(TWL6030_MMCDETECT_INT_MASK,
 229                                                 REG_INT_MSK_LINE_B);
 230         twl6030_interrupt_unmask(TWL6030_MMCDETECT_INT_MASK,
 231                                                 REG_INT_MSK_STS_B);
 232         /*
 233          * Initially Configuring MMC_CTRL for receiving interrupts &
 234          * Card status on TWL6030 for MMC1
 235          */
 236         ret = twl_i2c_read_u8(TWL6030_MODULE_ID0, &reg_val, TWL6030_MMCCTRL);
 237         if (ret < 0) {
 238                 pr_err("twl6030: Failed to read MMCCTRL, error %d\n", ret);
 239                 return ret;
 240         }
 241         reg_val &= ~VMMC_AUTO_OFF;
 242         reg_val |= SW_FC;
 243         ret = twl_i2c_write_u8(TWL6030_MODULE_ID0, reg_val, TWL6030_MMCCTRL);
 244         if (ret < 0) {
 245                 pr_err("twl6030: Failed to write MMCCTRL, error %d\n", ret);
 246                 return ret;
 247         }
 248
 249         /* Configuring PullUp-PullDown register */
 250         ret = twl_i2c_read_u8(TWL6030_MODULE_ID0, &reg_val,
 251                                                 TWL6030_CFG_INPUT_PUPD3);
 252         if (ret < 0) {
 253                 pr_err("twl6030: Failed to read CFG_INPUT_PUPD3, error %d\n",
 254                                                                         ret);
 255                 return ret;
 256         }
 257         reg_val &= ~(MMC_PU | MMC_PD);
 258         ret = twl_i2c_write_u8(TWL6030_MODULE_ID0, reg_val,
 259                                                 TWL6030_CFG_INPUT_PUPD3);
 260         if (ret < 0) {
 261                 pr_err("twl6030: Failed to write CFG_INPUT_PUPD3, error %d\n",
 262                                                                         ret);
 263                 return ret;
 264         }
 265         return 0;
 266 }
 267 EXPORT_SYMBOL(twl6030_mmc_card_detect_config);
 268
 269 int twl6030_mmc_card_detect(struct device *dev, int slot)
 270 {
 271         int ret = -EIO;
 272         u8 read_reg = 0;
 273         struct platform_device *pdev = to_platform_device(dev);
 274
 275         if (pdev->id) {
 276                 /* TWL6030 provide's Card detect support for
 277                  * only MMC1 controller.
 278                  */
 279                 pr_err("Unknown MMC controller %d in %s\n", pdev->id, __func__);
 280                 return ret;
 281         }
 282         /*
 283          * BIT0 of MMC_CTRL on TWL6030 provides card status for MMC1
 284          * 0 - Card not present ,1 - Card present
 285          */
 286         ret = twl_i2c_read_u8(TWL6030_MODULE_ID0, &read_reg,
 287                                                 TWL6030_MMCCTRL);
 288         if (ret >= 0)
 289                 ret = read_reg & STS_MMC;
 290         return ret;
 291 }
 292 EXPORT_SYMBOL(twl6030_mmc_card_detect);
 293
 294 int twl6030_init_irq(int irq_num, unsigned irq_base, unsigned irq_end)
 295 {
 296
 297         int     status = 0;
 298         int     i;
 299         struct task_struct      *task;
 300         int ret;
 301         u8 mask[4];
 302
 303         static struct irq_chip  twl6030_irq_chip;
 304         mask[1] = 0xFF;
 305         mask[2] = 0xFF;
 306         mask[3] = 0xFF;
 307         ret = twl_i2c_write(TWL_MODULE_PIH, &mask[0],
 308                         REG_INT_MSK_LINE_A, 3); /* MASK ALL INT LINES */
 309         ret = twl_i2c_write(TWL_MODULE_PIH, &mask[0],
 310                         REG_INT_MSK_STS_A, 3); /* MASK ALL INT STS */
 311         ret = twl_i2c_write(TWL_MODULE_PIH, &mask[0],
 312                         REG_INT_STS_A, 3); /* clear INT_STS_A,B,C */
 313
 314         twl6030_irq_base = irq_base;
 315
 316         /* install an irq handler for each of the modules;
 317          * clone dummy irq_chip since PIH can't *do* anything
 318          */
 319         twl6030_irq_chip = dummy_irq_chip;
 320         twl6030_irq_chip.name = "twl6030";
 321         twl6030_irq_chip.irq_set_type = NULL;
 322
 323         for (i = irq_base; i < irq_end; i++) {
 324                 irq_set_chip_and_handler(i, &twl6030_irq_chip,
 325                                          handle_simple_irq);
 326                 activate_irq(i);
 327         }
 328
 329         twl6030_irq_next = i;
 330         pr_info("twl6030: %s (irq %d) chaining IRQs %d..%d\n", "PIH",
 331                         irq_num, irq_base, twl6030_irq_next - 1);
 332
 333         /* install an irq handler to demultiplex the TWL6030 interrupt */
 334         init_completion(&irq_event);
 335         task = kthread_run(twl6030_irq_thread, (void *)irq_num, "twl6030-irq");
 336         if (IS_ERR(task)) {
 337                 pr_err("twl6030: could not create irq %d thread!\n", irq_num);
 338                 status = PTR_ERR(task);
 339                 goto fail_kthread;
 340         }
 341
 342         status = request_irq(irq_num, handle_twl6030_pih, IRQF_DISABLED,
 343                                 "TWL6030-PIH", &irq_event);
 344         if (status < 0) {
 345                 pr_err("twl6030: could not claim irq%d: %d\n", irq_num, status);
 346                 goto fail_irq;
 347         }
 348         return status;
 349 fail_irq:
 350         free_irq(irq_num, &irq_event);
 351
 352 fail_kthread:
 353         for (i = irq_base; i < irq_end; i++)
 354                 irq_set_chip_and_handler(i, NULL, NULL);
 355         return status;
 356 }
 357
 358 int twl6030_exit_irq(void)
 359 {
 360
 361         if (twl6030_irq_base) {
 362                 pr_err("twl6030: can't yet clean up IRQs?\n");
 363                 return -ENOSYS;
 364         }
 365         return 0;
 366 }
 367