mfd: Add support for twl6030 irq framework

This patch adds support for phoenix interrupt framework. New iInterrupt
status register A, B, C are introduced in Phoenix and are cleared on write.
Due to the differences in interrupt handling with respect to TWL4030,
twl6030-irq.c is created for TWL6030 PMIC

Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Balaji T K <balajitk@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

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;
+}
+