Input: gpio-keys - keyboard driver for GPIO buttons

This is an interrupt-driven keyboard driver for simple buttons
connected directly to CPU GPIO lines of embedded ARM systems.
It supports pxa architectures and is used by a number of PDAs
and PocketPC phones in the handhelds.org kernel. Support for
other architectures, such as sa11xx and sc2410, will be added
once generic GPIO API is available.

Signed-off-by: Paul Sokolovsky <pmiscml@gmail.com>
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 147 insertions, 0 deletions

diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
new file mode 100644
index 000000000000..3a8f1b427a7f
--- /dev/null
+++ b/drivers/input/keyboard/gpio_keys.c
@@ -0,0 +1,147 @@
+/*
+ * Driver for keys on GPIO lines capable of generating interrupts.
+ *
+ * Copyright 2005 Phil Blundell
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/version.h>
+
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/sched.h>
+#include <linux/pm.h>
+#include <linux/sysctl.h>
+#include <linux/proc_fs.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/input.h>
+#include <linux/irq.h>
+
+#include <asm/arch/pxa-regs.h>
+#include <asm/arch/hardware.h>
+
+#include <asm/hardware/gpio_keys.h>
+
+static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
+{
+        int i;
+        struct platform_device *pdev = dev_id;
+        struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
+        struct input_dev *input = platform_get_drvdata(pdev);
+
+        for (i = 0; i < pdata->nbuttons; i++) {
+                int gpio = pdata->buttons[i].gpio;
+                if (irq == IRQ_GPIO(gpio)) {
+                        int state = ((GPLR(gpio) & GPIO_bit(gpio)) ? 1 : 0) ^ (pdata->buttons[i].active_low);
+
+                        input_report_key(input, pdata->buttons[i].keycode, state);
+                        input_sync(input);
+                }
+        }
+
+        return IRQ_HANDLED;
+}
+
+static int __devinit gpio_keys_probe(struct platform_device *pdev)
+{
+        struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
+        struct input_dev *input;
+        int i, error;
+
+        input = input_allocate_device();
+        if (!input)
+                return -ENOMEM;
+
+        platform_set_drvdata(pdev, input);
+
+        input->evbit[0] = BIT(EV_KEY);
+
+        input->name = pdev->name;
+        input->phys = "gpio-keys/input0";
+        input->cdev.dev = &pdev->dev;
+        input->private = pdata;
+
+        input->id.bustype = BUS_HOST;
+        input->id.vendor = 0x0001;
+        input->id.product = 0x0001;
+        input->id.version = 0x0100;
+
+        for (i = 0; i < pdata->nbuttons; i++) {
+                int code = pdata->buttons[i].keycode;
+                int irq = IRQ_GPIO(pdata->buttons[i].gpio);
+
+                set_irq_type(irq, IRQ_TYPE_EDGE_BOTH);
+                error = request_irq(irq, gpio_keys_isr, SA_SAMPLE_RANDOM,
+                                     pdata->buttons[i].desc ? pdata->buttons[i].desc : "gpio_keys",
+                                     pdev);
+                if (error) {
+                        printk(KERN_ERR "gpio-keys: unable to claim irq %d; error %d\n", irq, ret);
+                        goto fail;
+                }
+                set_bit(code, input->keybit);
+        }
+
+        error = input_register_device(input);
+        if (error) {
+                printk(KERN_ERR "Unable to register gpio-keys input device\n");
+                goto fail;
+        }
+
+        return 0;
+
+ fail:
+        for (i = i - 1; i >= 0; i--)
+                free_irq(IRQ_GPIO(pdata->buttons[i].gpio), pdev);
+
+        input_free_device(input);
+
+        return error;
+}
+
+static int __devexit gpio_keys_remove(struct platform_device *pdev)
+{
+        struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
+        struct input_dev *input = platform_get_drvdata(pdev);
+        int i;
+
+        for (i = 0; i < pdata->nbuttons; i++) {
+                int irq = IRQ_GPIO(pdata->buttons[i].gpio);
+                free_irq(irq, pdev);
+        }
+
+        input_unregister_device(input);
+
+        return 0;
+}
+
+struct platform_driver gpio_keys_device_driver = {
+        .probe          = gpio_keys_probe,
+        .remove         = __devexit_p(gpio_keys_remove),
+        .driver         = {
+                .name   = "gpio-keys",
+        }
+};
+
+static int __init gpio_keys_init(void)
+{
+        return platform_driver_register(&gpio_keys_device_driver);
+}
+
+static void __exit gpio_keys_exit(void)
+{
+        platform_driver_unregister(&gpio_keys_device_driver);
+}
+
+module_init(gpio_keys_init);
+module_exit(gpio_keys_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
+MODULE_DESCRIPTION("Keyboard driver for CPU GPIOs");