sh: mach-x3proto: Support for baseboard GPIOs.

This adds trivial support for the GPIOs implemented through the baseboard
CPLD, used for driving the button matrix.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 135 insertions, 0 deletions

diff --git a/arch/sh/boards/mach-x3proto/gpio.c b/arch/sh/boards/mach-x3proto/gpio.c
new file mode 100644
index 000000000000..9fcd7ce6aa42
--- /dev/null
+++ b/arch/sh/boards/mach-x3proto/gpio.c
@@ -0,0 +1,135 @@
+/*
+ * arch/sh/boards/mach-x3proto/gpio.c
+ *
+ * Renesas SH-X3 Prototype Baseboard GPIO Support.
+ *
+ * Copyright (C) 2010  Paul Mundt
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <mach/ilsel.h>
+#include <mach/hardware.h>
+
+#define KEYCTLR 0xb81c0000
+#define KEYOUTR 0xb81c0002
+#define KEYDETR 0xb81c0004
+
+static DEFINE_SPINLOCK(x3proto_gpio_lock);
+static unsigned int x3proto_gpio_irq_map[NR_BASEBOARD_GPIOS] = { 0, };
+
+static int x3proto_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
+{
+        unsigned long flags;
+        unsigned int data;
+
+        spin_lock_irqsave(&x3proto_gpio_lock, flags);
+        data = __raw_readw(KEYCTLR);
+        data |= (1 << gpio);
+        __raw_writew(data, KEYCTLR);
+        spin_unlock_irqrestore(&x3proto_gpio_lock, flags);
+
+        return 0;
+}
+
+static int x3proto_gpio_get(struct gpio_chip *chip, unsigned gpio)
+{
+        return !!(__raw_readw(KEYDETR) & (1 << gpio));
+}
+
+static int x3proto_gpio_to_irq(struct gpio_chip *chip, unsigned gpio)
+{
+        return x3proto_gpio_irq_map[gpio];
+}
+
+static void x3proto_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
+{
+        struct irq_chip *chip = get_irq_desc_chip(desc);
+        unsigned long mask;
+        int pin;
+
+        chip->mask_ack(irq);
+
+        mask = __raw_readw(KEYDETR);
+
+        for_each_set_bit(pin, &mask, NR_BASEBOARD_GPIOS)
+                generic_handle_irq(x3proto_gpio_to_irq(NULL, pin));
+
+        chip->unmask(irq);
+}
+
+struct gpio_chip x3proto_gpio_chip = {
+        .label                  = "x3proto-gpio",
+        .direction_input        = x3proto_gpio_direction_input,
+        .get                    = x3proto_gpio_get,
+        .to_irq                 = x3proto_gpio_to_irq,
+        .base                   = -1,
+        .ngpio                  = NR_BASEBOARD_GPIOS,
+};
+
+int __init x3proto_gpio_setup(void)
+{
+        unsigned int ilsel;
+        int ret, i;
+
+        ilsel = ilsel_enable(ILSEL_KEY);
+        if (unlikely(ilsel < 0))
+                return ilsel;
+
+        ret = gpiochip_add(&x3proto_gpio_chip);
+        if (unlikely(ret))
+                goto err_gpio;
+
+        for (i = 0; i < NR_BASEBOARD_GPIOS; i++) {
+                unsigned long flags;
+                unsigned int irq = create_irq();
+
+                if (unlikely(irq < 0)) {
+                        ret = -EINVAL;
+                        goto err_irq;
+                }
+
+                spin_lock_irqsave(&x3proto_gpio_lock, flags);
+                x3proto_gpio_irq_map[i] = irq;
+                set_irq_chip_and_handler_name(irq, &dummy_irq_chip,
+                                        handle_simple_irq, "gpio");
+                spin_unlock_irqrestore(&x3proto_gpio_lock, flags);
+        }
+
+        pr_info("registering '%s' support, handling GPIOs %u -> %u, "
+                "bound to IRQ %u\n",
+                x3proto_gpio_chip.label, x3proto_gpio_chip.base,
+                x3proto_gpio_chip.base + x3proto_gpio_chip.ngpio,
+                ilsel);
+
+        set_irq_chained_handler(ilsel, x3proto_gpio_irq_handler);
+        set_irq_wake(ilsel, 1);
+
+        return 0;
+
+err_irq:
+        for (; i >= 0; --i)
+                if (x3proto_gpio_irq_map[i])
+                        destroy_irq(x3proto_gpio_irq_map[i]);
+
+        ret = gpiochip_remove(&x3proto_gpio_chip);
+        if (unlikely(ret))
+                pr_err("Failed deregistering GPIO\n");
+
+err_gpio:
+        synchronize_irq(ilsel);
+
+        ilsel_disable(ILSEL_KEY);
+
+        return ret;
+}