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