diff --git a/arch/arm/mach-davinci/gpio.c b/arch/arm/mach-davinci/gpio.c
index b49e9d0..1aba41c 100644
--- a/arch/arm/mach-davinci/gpio.c
+++ b/arch/arm/mach-davinci/gpio.c
@@ -20,6 +20,7 @@
 #include <linux/irq.h>
 #include <linux/bitops.h>
 
+#include <mach/cputype.h>
 #include <mach/irqs.h>
 #include <mach/hardware.h>
 #include <mach/gpio.h>
@@ -36,9 +37,10 @@
 
 static struct davinci_gpio chips[DIV_ROUND_UP(DAVINCI_N_GPIO, 32)];
 
+static unsigned __initdata ngpio;
 
 /* create a non-inlined version */
-static struct gpio_controller *__iomem __init gpio2controller(unsigned gpio)
+static struct gpio_controller __iomem * __init gpio2controller(unsigned gpio)
 {
 	return __gpio_to_controller(gpio);
 }
@@ -114,9 +116,30 @@
 {
 	int i, base;
 
-	for (i = 0, base = 0;
-			i < ARRAY_SIZE(chips);
-			i++, base += 32) {
+	/* The gpio banks conceptually expose a segmented bitmap,
+	 * and "ngpio" is one more than the largest zero-based
+	 * bit index that's valid.
+	 */
+	if (cpu_is_davinci_dm355()) {		/* or dm335() */
+		ngpio = 104;
+	} else if (cpu_is_davinci_dm644x()) {	/* or dm337() */
+		ngpio = 71;
+	} else if (cpu_is_davinci_dm646x()) {
+		/* NOTE:  each bank has several "reserved" bits,
+		 * unusable as GPIOs.  Only 33 of the GPIO numbers
+		 * are usable, and we're not rejecting the others.
+		 */
+		ngpio = 43;
+	} else {
+		/* if cpu_is_davinci_dm643x() ngpio = 111 */
+		pr_err("GPIO setup:  how many GPIOs?\n");
+		return -EINVAL;
+	}
+
+	if (WARN_ON(DAVINCI_N_GPIO < ngpio))
+		ngpio = DAVINCI_N_GPIO;
+
+	for (i = 0, base = 0; base < ngpio; i++, base += 32) {
 		chips[i].chip.label = "DaVinci";
 
 		chips[i].chip.direction_input = davinci_direction_in;
@@ -125,7 +148,7 @@
 		chips[i].chip.set = davinci_gpio_set;
 
 		chips[i].chip.base = base;
-		chips[i].chip.ngpio = DAVINCI_N_GPIO - base;
+		chips[i].chip.ngpio = ngpio - base;
 		if (chips[i].chip.ngpio > 32)
 			chips[i].chip.ngpio = 32;
 
@@ -143,11 +166,11 @@
  * We expect irqs will normally be set up as input pins, but they can also be
  * used as output pins ... which is convenient for testing.
  *
- * NOTE:  GPIO0..GPIO7 also have direct INTC hookups, which work in addition
- * to their GPIOBNK0 irq (but with a bit less overhead).  But we don't have
- * a good way to hook those up ...
+ * NOTE:  The first few GPIOs also have direct INTC hookups in addition
+ * to their GPIOBNK0 irq, with a bit less overhead but less flexibility
+ * on triggering (e.g. no edge options).  We don't try to use those.
  *
- * All those INTC hookups (GPIO0..GPIO7 plus five IRQ banks) can also
+ * All those INTC hookups (direct, plus several IRQ banks) can also
  * serve as EDMA event triggers.
  */
 
@@ -235,29 +258,42 @@
 }
 
 /*
- * NOTE:  for suspend/resume, probably best to make a sysdev (and class)
- * with its suspend/resume calls hooking into the results of the set_wake()
+ * NOTE:  for suspend/resume, probably best to make a platform_device with
+ * suspend_late/resume_resume calls hooking into results of the set_wake()
  * calls ... so if no gpios are wakeup events the clock can be disabled,
  * with outputs left at previously set levels, and so that VDD3P3V.IOPWDN0
- * can be set appropriately for GPIOV33 pins.
+ * (dm6446) can be set appropriately for GPIOV33 pins.
  */
 
 static int __init davinci_gpio_irq_setup(void)
 {
 	unsigned	gpio, irq, bank;
+	unsigned	bank_irq;
 	struct clk	*clk;
+	u32		binten = 0;
+
+	if (cpu_is_davinci_dm355()) {		/* or dm335() */
+		bank_irq = IRQ_DM355_GPIOBNK0;
+	} else if (cpu_is_davinci_dm644x()) {
+		bank_irq = IRQ_GPIOBNK0;
+	} else if (cpu_is_davinci_dm646x()) {
+		bank_irq = IRQ_DM646X_GPIOBNK0;
+	} else {
+		printk(KERN_ERR "Don't know first GPIO bank IRQ.\n");
+		return -EINVAL;
+	}
 
 	clk = clk_get(NULL, "gpio");
 	if (IS_ERR(clk)) {
 		printk(KERN_ERR "Error %ld getting gpio clock?\n",
 		       PTR_ERR(clk));
-		return 0;
+		return PTR_ERR(clk);
 	}
-
 	clk_enable(clk);
 
-	for (gpio = 0, irq = gpio_to_irq(0), bank = IRQ_GPIOBNK0;
-	     gpio < DAVINCI_N_GPIO; bank++) {
+	for (gpio = 0, irq = gpio_to_irq(0), bank = 0;
+			gpio < ngpio;
+			bank++, bank_irq++) {
 		struct gpio_controller	*__iomem g = gpio2controller(gpio);
 		unsigned		i;
 
@@ -265,28 +301,28 @@
 		__raw_writel(~0, &g->clr_rising);
 
 		/* set up all irqs in this bank */
-		set_irq_chained_handler(bank, gpio_irq_handler);
-		set_irq_chip_data(bank, g);
-		set_irq_data(bank, (void *)irq);
+		set_irq_chained_handler(bank_irq, gpio_irq_handler);
+		set_irq_chip_data(bank_irq, g);
+		set_irq_data(bank_irq, (void *)irq);
 
-		for (i = 0; i < 16 && gpio < DAVINCI_N_GPIO;
-		     i++, irq++, gpio++) {
+		for (i = 0; i < 16 && gpio < ngpio; i++, irq++, gpio++) {
 			set_irq_chip(irq, &gpio_irqchip);
 			set_irq_chip_data(irq, g);
 			set_irq_handler(irq, handle_simple_irq);
 			set_irq_flags(irq, IRQF_VALID);
 		}
+
+		binten |= BIT(bank);
 	}
 
 	/* BINTEN -- per-bank interrupt enable. genirq would also let these
 	 * bits be set/cleared dynamically.
 	 */
-	__raw_writel(0x1f, (void *__iomem)
+	__raw_writel(binten, (void *__iomem)
 		     IO_ADDRESS(DAVINCI_GPIO_BASE + 0x08));
 
 	printk(KERN_INFO "DaVinci: %d gpio irqs\n", irq - gpio_to_irq(0));
 
 	return 0;
 }
-
 arch_initcall(davinci_gpio_irq_setup);