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