msm: add sirc interrupt controller driver.

Scorpion-based SOCs from Qualcomm use a different interrupt
controller 'sirc'.

Signed-off-by: Gregory Bean <gbean@codeaurora.org>
Signed-off-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>

1 files changed, 177 insertions, 0 deletions

diff --git a/arch/arm/mach-msm/sirc.c b/arch/arm/mach-msm/sirc.c
new file mode 100644
index 0000000..b079452
--- /dev/null
+++ b/arch/arm/mach-msm/sirc.c
@@ -0,0 +1,177 @@
+/* Copyright (c) 2008-2009, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ */
+
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <asm/irq.h>
+
+static unsigned int int_enable;
+static unsigned int wake_enable;
+
+static struct sirc_regs_t sirc_regs = {
+	.int_enable       = SPSS_SIRC_INT_ENABLE,
+	.int_enable_clear = SPSS_SIRC_INT_ENABLE_CLEAR,
+	.int_enable_set   = SPSS_SIRC_INT_ENABLE_SET,
+	.int_type         = SPSS_SIRC_INT_TYPE,
+	.int_polarity     = SPSS_SIRC_INT_POLARITY,
+	.int_clear        = SPSS_SIRC_INT_CLEAR,
+};
+
+static struct sirc_cascade_regs sirc_reg_table[] = {
+	{
+		.int_status  = SPSS_SIRC_IRQ_STATUS,
+		.cascade_irq = INT_SIRC_0,
+	}
+};
+
+static unsigned int save_type;
+static unsigned int save_polarity;
+
+/* Mask off the given interrupt. Keep the int_enable mask in sync with
+   the enable reg, so it can be restored after power collapse. */
+static void sirc_irq_mask(unsigned int irq)
+{
+	unsigned int mask;
+
+
+	mask = 1 << (irq - FIRST_SIRC_IRQ);
+	writel(mask, sirc_regs.int_enable_clear);
+	int_enable &= ~mask;
+	return;
+}
+
+/* Unmask the given interrupt. Keep the int_enable mask in sync with
+   the enable reg, so it can be restored after power collapse. */
+static void sirc_irq_unmask(unsigned int irq)
+{
+	unsigned int mask;
+
+	mask = 1 << (irq - FIRST_SIRC_IRQ);
+	writel(mask, sirc_regs.int_enable_set);
+	int_enable |= mask;
+	return;
+}
+
+static void sirc_irq_ack(unsigned int irq)
+{
+	unsigned int mask;
+
+	mask = 1 << (irq - FIRST_SIRC_IRQ);
+	writel(mask, sirc_regs.int_clear);
+	return;
+}
+
+static int sirc_irq_set_wake(unsigned int irq, unsigned int on)
+{
+	unsigned int mask;
+
+	/* Used to set the interrupt enable mask during power collapse. */
+	mask = 1 << (irq - FIRST_SIRC_IRQ);
+	if (on)
+		wake_enable |= mask;
+	else
+		wake_enable &= ~mask;
+
+	return 0;
+}
+
+static int sirc_irq_set_type(unsigned int irq, unsigned int flow_type)
+{
+	unsigned int mask;
+	unsigned int val;
+
+	mask = 1 << (irq - FIRST_SIRC_IRQ);
+	val = readl(sirc_regs.int_polarity);
+
+	if (flow_type & (IRQF_TRIGGER_LOW | IRQF_TRIGGER_FALLING))
+		val |= mask;
+	else
+		val &= ~mask;
+
+	writel(val, sirc_regs.int_polarity);
+
+	val = readl(sirc_regs.int_type);
+	if (flow_type & (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)) {
+		val |= mask;
+		irq_desc[irq].handle_irq = handle_edge_irq;
+	} else {
+		val &= ~mask;
+		irq_desc[irq].handle_irq = handle_level_irq;
+	}
+
+	writel(val, sirc_regs.int_type);
+
+	return 0;
+}
+
+/* Finds the pending interrupt on the passed cascade irq and redrives it */
+static void sirc_irq_handler(unsigned int irq, struct irq_desc *desc)
+{
+	unsigned int reg = 0;
+	unsigned int sirq;
+	unsigned int status;
+
+	while ((reg < ARRAY_SIZE(sirc_reg_table)) &&
+		(sirc_reg_table[reg].cascade_irq != irq))
+		reg++;
+
+	status = readl(sirc_reg_table[reg].int_status);
+	status &= SIRC_MASK;
+	if (status == 0)
+		return;
+
+	for (sirq = 0;
+	     (sirq < NR_SIRC_IRQS) && ((status & (1U << sirq)) == 0);
+	     sirq++)
+		;
+	generic_handle_irq(sirq+FIRST_SIRC_IRQ);
+
+	desc->chip->ack(irq);
+}
+
+static struct irq_chip sirc_irq_chip = {
+	.name      = "sirc",
+	.ack       = sirc_irq_ack,
+	.mask      = sirc_irq_mask,
+	.unmask    = sirc_irq_unmask,
+	.set_wake  = sirc_irq_set_wake,
+	.set_type  = sirc_irq_set_type,
+};
+
+void __init msm_init_sirc(void)
+{
+	int i;
+
+	int_enable = 0;
+	wake_enable = 0;
+
+	for (i = FIRST_SIRC_IRQ; i < LAST_SIRC_IRQ; i++) {
+		set_irq_chip(i, &sirc_irq_chip);
+		set_irq_handler(i, handle_edge_irq);
+		set_irq_flags(i, IRQF_VALID);
+	}
+
+	for (i = 0; i < ARRAY_SIZE(sirc_reg_table); i++) {
+		set_irq_chained_handler(sirc_reg_table[i].cascade_irq,
+					sirc_irq_handler);
+		set_irq_wake(sirc_reg_table[i].cascade_irq, 1);
+	}
+	return;
+}
+