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;
+}
+