[ARM] 3374/1: ep93xx: gpio interrupt support

Patch from Lennert Buytenhek

Add GPIO interrupt support for the first 16 GPIO lines (port A
and B.)

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 133 insertions, 0 deletions

diff --git a/arch/arm/mach-ep93xx/core.c b/arch/arm/mach-ep93xx/core.c
index 7d3e79990fa..865427bfad7 100644
--- a/arch/arm/mach-ep93xx/core.c
+++ b/arch/arm/mach-ep93xx/core.c
@@ -150,6 +150,26 @@ struct sys_timer ep93xx_timer = {
 /*************************************************************************
  * GPIO handling for EP93xx
  *************************************************************************/
+static unsigned char gpio_int_enable[2];
+static unsigned char gpio_int_type1[2];
+static unsigned char gpio_int_type2[2];
+
+static void update_gpio_ab_int_params(int port)
+{
+        if (port == 0) {
+                __raw_writeb(0, EP93XX_GPIO_A_INT_ENABLE);
+                __raw_writeb(gpio_int_type2[0], EP93XX_GPIO_A_INT_TYPE2);
+                __raw_writeb(gpio_int_type1[0], EP93XX_GPIO_A_INT_TYPE1);
+                __raw_writeb(gpio_int_enable[0], EP93XX_GPIO_A_INT_ENABLE);
+        } else if (port == 1) {
+                __raw_writeb(0, EP93XX_GPIO_B_INT_ENABLE);
+                __raw_writeb(gpio_int_type2[1], EP93XX_GPIO_B_INT_TYPE2);
+                __raw_writeb(gpio_int_type1[1], EP93XX_GPIO_B_INT_TYPE1);
+                __raw_writeb(gpio_int_enable[1], EP93XX_GPIO_B_INT_ENABLE);
+        }
+}
+
+
 static unsigned char data_register_offset[8] = {
         0x00, 0x04, 0x08, 0x0c, 0x20, 0x30, 0x38, 0x40,
 };
@@ -169,6 +189,11 @@ void gpio_line_config(int line, int direction)
 
         local_irq_save(flags);
         if (direction == GPIO_OUT) {
+                if (line >= 0 && line < 16) {
+                        gpio_int_enable[line >> 3] &= ~(1 << (line & 7));
+                        update_gpio_ab_int_params(line >> 3);
+                }
+
                 v = __raw_readb(data_direction_register);
                 v |= 1 << (line & 7);
                 __raw_writeb(v, data_direction_register);
@@ -217,10 +242,118 @@ EXPORT_SYMBOL(gpio_line_set);
 /*************************************************************************
  * EP93xx IRQ handling
  *************************************************************************/
+static void ep93xx_gpio_ab_irq_handler(unsigned int irq,
+                struct irqdesc *desc, struct pt_regs *regs)
+{
+        unsigned char status;
+        int i;
+
+        status = __raw_readb(EP93XX_GPIO_A_INT_STATUS);
+        for (i = 0; i < 8; i++) {
+                if (status & (1 << i)) {
+                        desc = irq_desc + IRQ_EP93XX_GPIO(0) + i;
+                        desc_handle_irq(IRQ_EP93XX_GPIO(0) + i, desc, regs);
+                }
+        }
+
+        status = __raw_readb(EP93XX_GPIO_B_INT_STATUS);
+        for (i = 0; i < 8; i++) {
+                if (status & (1 << i)) {
+                        desc = irq_desc + IRQ_EP93XX_GPIO(8) + i;
+                        desc_handle_irq(IRQ_EP93XX_GPIO(8) + i, desc, regs);
+                }
+        }
+}
+
+static void ep93xx_gpio_ab_irq_mask_ack(unsigned int irq)
+{
+        int line = irq - IRQ_EP93XX_GPIO(0);
+        int port = line >> 3;
+
+        gpio_int_enable[port] &= ~(1 << (line & 7));
+        update_gpio_ab_int_params(port);
+
+        if (line >> 3) {
+                __raw_writel(1 << (line & 7), EP93XX_GPIO_B_INT_ACK);
+        } else {
+                __raw_writel(1 << (line & 7), EP93XX_GPIO_A_INT_ACK);
+        }
+}
+
+static void ep93xx_gpio_ab_irq_mask(unsigned int irq)
+{
+        int line = irq - IRQ_EP93XX_GPIO(0);
+        int port = line >> 3;
+
+        gpio_int_enable[port] &= ~(1 << (line & 7));
+        update_gpio_ab_int_params(port);
+}
+
+static void ep93xx_gpio_ab_irq_unmask(unsigned int irq)
+{
+        int line = irq - IRQ_EP93XX_GPIO(0);
+        int port = line >> 3;
+
+        gpio_int_enable[port] |= 1 << (line & 7);
+        update_gpio_ab_int_params(port);
+}
+
+
+/*
+ * gpio_int_type1 controls whether the interrupt is level (0) or
+ * edge (1) triggered, while gpio_int_type2 controls whether it
+ * triggers on low/falling (0) or high/rising (1).
+ */
+static int ep93xx_gpio_ab_irq_type(unsigned int irq, unsigned int type)
+{
+        int port;
+        int line;
+
+        line = irq - IRQ_EP93XX_GPIO(0);
+        gpio_line_config(line, GPIO_IN);
+
+        port = line >> 3;
+        line &= 7;
+
+        if (type & IRQT_RISING) {
+                gpio_int_type1[port] |= 1 << line;
+                gpio_int_type2[port] |= 1 << line;
+        } else if (type & IRQT_FALLING) {
+                gpio_int_type1[port] |= 1 << line;
+                gpio_int_type2[port] &= ~(1 << line);
+        } else if (type & IRQT_HIGH) {
+                gpio_int_type1[port] &= ~(1 << line);
+                gpio_int_type2[port] |= 1 << line;
+        } else if (type & IRQT_LOW) {
+                gpio_int_type1[port] &= ~(1 << line);
+                gpio_int_type2[port] &= ~(1 << line);
+        }
+        update_gpio_ab_int_params(port);
+
+        return 0;
+}
+
+static struct irqchip ep93xx_gpio_ab_irq_chip = {
+        .ack            = ep93xx_gpio_ab_irq_mask_ack,
+        .mask           = ep93xx_gpio_ab_irq_mask,
+        .unmask         = ep93xx_gpio_ab_irq_unmask,
+        .set_type       = ep93xx_gpio_ab_irq_type,
+};
+
+
 void __init ep93xx_init_irq(void)
 {
+        int irq;
+
         vic_init((void *)EP93XX_VIC1_BASE, 0, EP93XX_VIC1_VALID_IRQ_MASK);
         vic_init((void *)EP93XX_VIC2_BASE, 32, EP93XX_VIC2_VALID_IRQ_MASK);
+
+        for (irq = IRQ_EP93XX_GPIO(0) ; irq <= IRQ_EP93XX_GPIO(15); irq++) {
+                set_irq_chip(irq, &ep93xx_gpio_ab_irq_chip);
+                set_irq_handler(irq, do_level_IRQ);
+                set_irq_flags(irq, IRQF_VALID);
+        }
+        set_irq_chained_handler(IRQ_EP93XX_GPIO_AB, ep93xx_gpio_ab_irq_handler);
 }