diff options
Diffstat (limited to 'drivers/mfd/twl6030-irq.c')
| -rw-r--r-- | drivers/mfd/twl6030-irq.c | 299 |
1 files changed, 299 insertions, 0 deletions
diff --git a/drivers/mfd/twl6030-irq.c b/drivers/mfd/twl6030-irq.c new file mode 100644 index 000000000000..10bf228ad626 --- /dev/null +++ b/drivers/mfd/twl6030-irq.c @@ -0,0 +1,299 @@ +/* + * twl6030-irq.c - TWL6030 irq support + * + * Copyright (C) 2005-2009 Texas Instruments, Inc. + * + * Modifications to defer interrupt handling to a kernel thread: + * Copyright (C) 2006 MontaVista Software, Inc. + * + * Based on tlv320aic23.c: + * Copyright (c) by Kai Svahn <kai.svahn@nokia.com> + * + * Code cleanup and modifications to IRQ handler. + * by syed khasim <x0khasim@ti.com> + * + * TWL6030 specific code and IRQ handling changes by + * Jagadeesh Bhaskar Pakaravoor <j-pakaravoor@ti.com> + * Balaji T K <balajitk@ti.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/kthread.h> +#include <linux/i2c/twl.h> + +/* + * TWL6030 (unlike its predecessors, which had two level interrupt handling) + * three interrupt registers INT_STS_A, INT_STS_B and INT_STS_C. + * It exposes status bits saying who has raised an interrupt. There are + * three mask registers that corresponds to these status registers, that + * enables/disables these interrupts. + * + * We set up IRQs starting at a platform-specified base. An interrupt map table, + * specifies mapping between interrupt number and the associated module. + * + */ + +static int twl6030_interrupt_mapping[24] = { + PWR_INTR_OFFSET, /* Bit 0 PWRON */ + PWR_INTR_OFFSET, /* Bit 1 RPWRON */ + PWR_INTR_OFFSET, /* Bit 2 BAT_VLOW */ + RTC_INTR_OFFSET, /* Bit 3 RTC_ALARM */ + RTC_INTR_OFFSET, /* Bit 4 RTC_PERIOD */ + HOTDIE_INTR_OFFSET, /* Bit 5 HOT_DIE */ + SMPSLDO_INTR_OFFSET, /* Bit 6 VXXX_SHORT */ + SMPSLDO_INTR_OFFSET, /* Bit 7 VMMC_SHORT */ + + SMPSLDO_INTR_OFFSET, /* Bit 8 VUSIM_SHORT */ + BATDETECT_INTR_OFFSET, /* Bit 9 BAT */ + SIMDETECT_INTR_OFFSET, /* Bit 10 SIM */ + MMCDETECT_INTR_OFFSET, /* Bit 11 MMC */ + RSV_INTR_OFFSET, /* Bit 12 Reserved */ + MADC_INTR_OFFSET, /* Bit 13 GPADC_RT_EOC */ + MADC_INTR_OFFSET, /* Bit 14 GPADC_SW_EOC */ + GASGAUGE_INTR_OFFSET, /* Bit 15 CC_AUTOCAL */ + + USBOTG_INTR_OFFSET, /* Bit 16 ID_WKUP */ + USBOTG_INTR_OFFSET, /* Bit 17 VBUS_WKUP */ + USBOTG_INTR_OFFSET, /* Bit 18 ID */ + USBOTG_INTR_OFFSET, /* Bit 19 VBUS */ + CHARGER_INTR_OFFSET, /* Bit 20 CHRG_CTRL */ + CHARGER_INTR_OFFSET, /* Bit 21 EXT_CHRG */ + CHARGER_INTR_OFFSET, /* Bit 22 INT_CHRG */ + RSV_INTR_OFFSET, /* Bit 23 Reserved */ +}; +/*----------------------------------------------------------------------*/ + +static unsigned twl6030_irq_base; + +static struct completion irq_event; + +/* + * This thread processes interrupts reported by the Primary Interrupt Handler. + */ +static int twl6030_irq_thread(void *data) +{ + long irq = (long)data; + static unsigned i2c_errors; + static const unsigned max_i2c_errors = 100; + int ret; + + current->flags |= PF_NOFREEZE; + + while (!kthread_should_stop()) { + int i; + union { + u8 bytes[4]; + u32 int_sts; + } sts; + + /* Wait for IRQ, then read PIH irq status (also blocking) */ + wait_for_completion_interruptible(&irq_event); + + /* read INT_STS_A, B and C in one shot using a burst read */ + ret = twl_i2c_read(TWL_MODULE_PIH, sts.bytes, + REG_INT_STS_A, 3); + if (ret) { + pr_warning("twl6030: I2C error %d reading PIH ISR\n", + ret); + if (++i2c_errors >= max_i2c_errors) { + printk(KERN_ERR "Maximum I2C error count" + " exceeded. Terminating %s.\n", + __func__); + break; + } + complete(&irq_event); + continue; + } + + + + sts.bytes[3] = 0; /* Only 24 bits are valid*/ + + for (i = 0; sts.int_sts; sts.int_sts >>= 1, i++) { + local_irq_disable(); + if (sts.int_sts & 0x1) { + int module_irq = twl6030_irq_base + + twl6030_interrupt_mapping[i]; + struct irq_desc *d = irq_to_desc(module_irq); + + if (!d) { + pr_err("twl6030: Invalid SIH IRQ: %d\n", + module_irq); + return -EINVAL; + } + + /* These can't be masked ... always warn + * if we get any surprises. + */ + if (d->status & IRQ_DISABLED) + note_interrupt(module_irq, d, + IRQ_NONE); + else + d->handle_irq(module_irq, d); + + } + local_irq_enable(); + } + ret = twl_i2c_write(TWL_MODULE_PIH, sts.bytes, + REG_INT_STS_A, 3); /* clear INT_STS_A */ + if (ret) + pr_warning("twl6030: I2C error in clearing PIH ISR\n"); + + enable_irq(irq); + } + + return 0; +} + +/* + * handle_twl6030_int() is the desc->handle method for the twl6030 interrupt. + * This is a chained interrupt, so there is no desc->action method for it. + * Now we need to query the interrupt controller in the twl6030 to determine + * which module is generating the interrupt request. However, we can't do i2c + * transactions in interrupt context, so we must defer that work to a kernel + * thread. All we do here is acknowledge and mask the interrupt and wakeup + * the kernel thread. + */ +static irqreturn_t handle_twl6030_pih(int irq, void *devid) +{ + disable_irq_nosync(irq); + complete(devid); + return IRQ_HANDLED; +} + +/*----------------------------------------------------------------------*/ + +static inline void activate_irq(int irq) +{ +#ifdef CONFIG_ARM + /* ARM requires an extra step to clear IRQ_NOREQUEST, which it + * sets on behalf of every irq_chip. Also sets IRQ_NOPROBE. + */ + set_irq_flags(irq, IRQF_VALID); +#else + /* same effect on other architectures */ + set_irq_noprobe(irq); +#endif +} + +/*----------------------------------------------------------------------*/ + +static unsigned twl6030_irq_next; + +/*----------------------------------------------------------------------*/ +int twl6030_interrupt_unmask(u8 bit_mask, u8 offset) +{ + int ret; + u8 unmask_value; + ret = twl_i2c_read_u8(TWL_MODULE_PIH, &unmask_value, + REG_INT_STS_A + offset); + unmask_value &= (~(bit_mask)); + ret |= twl_i2c_write_u8(TWL_MODULE_PIH, unmask_value, + REG_INT_STS_A + offset); /* unmask INT_MSK_A/B/C */ + return ret; +} +EXPORT_SYMBOL(twl6030_interrupt_unmask); + +int twl6030_interrupt_mask(u8 bit_mask, u8 offset) +{ + int ret; + u8 mask_value; + ret = twl_i2c_read_u8(TWL_MODULE_PIH, &mask_value, + REG_INT_STS_A + offset); + mask_value |= (bit_mask); + ret |= twl_i2c_write_u8(TWL_MODULE_PIH, mask_value, + REG_INT_STS_A + offset); /* mask INT_MSK_A/B/C */ + return ret; +} +EXPORT_SYMBOL(twl6030_interrupt_mask); + +int twl6030_init_irq(int irq_num, unsigned irq_base, unsigned irq_end) +{ + + int status = 0; + int i; + struct task_struct *task; + int ret; + u8 mask[4]; + + static struct irq_chip twl6030_irq_chip; + mask[1] = 0xFF; + mask[2] = 0xFF; + mask[3] = 0xFF; + ret = twl_i2c_write(TWL_MODULE_PIH, &mask[0], + REG_INT_MSK_LINE_A, 3); /* MASK ALL INT LINES */ + ret = twl_i2c_write(TWL_MODULE_PIH, &mask[0], + REG_INT_MSK_STS_A, 3); /* MASK ALL INT STS */ + ret = twl_i2c_write(TWL_MODULE_PIH, &mask[0], + REG_INT_STS_A, 3); /* clear INT_STS_A,B,C */ + + twl6030_irq_base = irq_base; + + /* install an irq handler for each of the modules; + * clone dummy irq_chip since PIH can't *do* anything + */ + twl6030_irq_chip = dummy_irq_chip; + twl6030_irq_chip.name = "twl6030"; + twl6030_irq_chip.set_type = NULL; + + for (i = irq_base; i < irq_end; i++) { + set_irq_chip_and_handler(i, &twl6030_irq_chip, + handle_simple_irq); + activate_irq(i); + } + + twl6030_irq_next = i; + pr_info("twl6030: %s (irq %d) chaining IRQs %d..%d\n", "PIH", + irq_num, irq_base, twl6030_irq_next - 1); + + /* install an irq handler to demultiplex the TWL6030 interrupt */ + init_completion(&irq_event); + task = kthread_run(twl6030_irq_thread, (void *)irq_num, "twl6030-irq"); + if (IS_ERR(task)) { + pr_err("twl6030: could not create irq %d thread!\n", irq_num); + status = PTR_ERR(task); + goto fail_kthread; + } + + status = request_irq(irq_num, handle_twl6030_pih, IRQF_DISABLED, + "TWL6030-PIH", &irq_event); + if (status < 0) { + pr_err("twl6030: could not claim irq%d: %d\n", irq_num, status); + goto fail_irq; + } + return status; +fail_irq: + free_irq(irq_num, &irq_event); + +fail_kthread: + for (i = irq_base; i < irq_end; i++) + set_irq_chip_and_handler(i, NULL, NULL); + return status; +} + +int twl6030_exit_irq(void) +{ + + if (twl6030_irq_base) { + pr_err("twl6030: can't yet clean up IRQs?\n"); + return -ENOSYS; + } + return 0; +} + |