add gpio keyboard support

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

drivers/Kconfig

@@ -14,5 +14,6 @@ source "drivers/clk/Kconfig"
 source "drivers/mfd/Kconfig"
 source "drivers/led/Kconfig"
 source "drivers/eeprom/Kconfig"
+source "drivers/input/Kconfig"
 
 endmenu

drivers/Makefile

@@ -13,3 +13,4 @@ obj-y	+= clk/
 obj-y	+= mfd/
 obj-$(CONFIG_LED) += led/
 obj-y	+= eeprom/
+obj-y	+= input/

drivers/input/Kconfig

@@ -0,0 +1,19 @@
+#
+# Input device configuration
+#
+
+menu "Input device support"
+
+config KEYBOARD_GPIO
+	bool "GPIO Buttons"
+	depends on GENERIC_GPIO
+	help
+	  This driver implements support for buttons connected
+	  to GPIO pins of various CPUs (and some other chips).
+
+	  Say Y here if your device has buttons connected
+	  directly to such GPIO pins.  Your board-specific
+	  setup logic must also provide a platform device,
+	  with configuration data saying which GPIOs are used.
+
+endmenu

drivers/input/Makefile

@@ -0,0 +1 @@
+obj-$(CONFIG_KEYBOARD_GPIO) += gpio_keys.o

drivers/input/gpio_keys.c

@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2011 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
+ *
+ * Under GPLv2
+ */
+
+#include <common.h>
+#include <errno.h>
+#include <init.h>
+#include <clock.h>
+#include <gpio_keys.h>
+#include <poller.h>
+#include <gpio.h>
+
+static inline struct gpio_keys_platform_data *
+poller_to_gk_pdata(struct poller_struct *poller)
+{
+	return container_of(poller, struct gpio_keys_platform_data, poller);
+}
+
+static inline struct gpio_keys_platform_data *
+cdev_to_gk_pdata(struct console_device *cdev)
+{
+	return container_of(cdev, struct gpio_keys_platform_data, cdev);
+}
+
+static void gpio_key_poller(struct poller_struct *poller)
+{
+	struct gpio_keys_platform_data *pdata = poller_to_gk_pdata(poller);
+	struct gpio_keys_button *gb;
+	int i, val;
+
+	for (i = 0; i < pdata->nbuttons; i++) {
+
+		gb = &pdata->buttons[i];
+		val = gpio_get_value(gb->gpio);
+
+		if (val != gb->previous_state && val != gb->active_low) {
+			kfifo_put(pdata->recv_fifo, (u_char*)&gb->code, sizeof(int));
+			debug("pressed gpio(%d) as %d\n", gb->gpio, gb->code);
+		}
+		gb->previous_state = val;
+	}
+}
+
+static int gpio_keys_tstc(struct console_device *cdev)
+{
+	struct gpio_keys_platform_data *pdata = cdev_to_gk_pdata(cdev);
+
+	return (kfifo_len(pdata->recv_fifo) == 0) ? 0 : 1;
+}
+
+static int gpio_keys_getc(struct console_device *cdev)
+{
+	int code = 0;
+	struct gpio_keys_platform_data *pdata = cdev_to_gk_pdata(cdev);
+
+	kfifo_get(pdata->recv_fifo, (u_char*)&code, sizeof(int));
+	return code;
+}
+
+static int __init gpio_keys_probe(struct device_d *dev)
+{
+	int ret, i, gpio;
+	struct gpio_keys_platform_data *pdata;
+	struct console_device *cdev;
+
+	pdata = dev->platform_data;
+
+	if (!pdata) {
+		/* small (so we copy it) but critical! */
+		pr_err("missing platform_data\n");
+		return -ENODEV;
+	}
+
+	if (!pdata->fifo_size)
+		pdata->fifo_size = 50;
+
+	pdata->recv_fifo = kfifo_alloc(pdata->fifo_size);
+
+	for (i = 0; i < pdata->nbuttons; i++) {
+		gpio = pdata->buttons->gpio;
+		ret = gpio_request(gpio, "gpio_keys");
+		if (ret) {
+			pr_err("gpio_keys: (%d) can not be requested\n", gpio);
+			return ret;
+		}
+		gpio_direction_input(gpio);
+	}
+
+	pdata->poller.func = gpio_key_poller;
+
+	cdev = &pdata->cdev;
+	dev->type_data = cdev;
+	cdev->dev = dev;
+	cdev->f_caps = CONSOLE_STDIN;
+	cdev->tstc = gpio_keys_tstc;
+	cdev->getc = gpio_keys_getc;
+
+	console_register(&pdata->cdev);
+
+	return poller_register(&pdata->poller);
+}
+
+static struct driver_d gpio_keys_driver = {
+	.name	= "gpio_keys",
+	.probe	= gpio_keys_probe,
+};
+
+static int gpio_keys_init(void)
+{
+	register_driver(&gpio_keys_driver);
+	return 0;
+}
+device_initcall(gpio_keys_init);

include/driver.h

@@ -260,6 +260,11 @@ static inline struct device_d *add_generic_usb_ehci_device(int id,
 	return add_usb_ehci_device(id, base + 0x100, base + 0x140, pdata);
 }
 
+static inline struct device_d *add_gpio_keys_device(int id, void *pdata)
+{
+	return add_generic_device_res("gpio_keys", id, 0, 0, pdata);
+}
+
 /* linear list over all available devices
  */
 extern struct list_head device_list;

include/gpio_keys.h

@@ -0,0 +1,30 @@
+#ifndef _GPIO_KEYS_H
+#define _GPIO_KEYS_H
+
+#include <poller.h>
+#include <kfifo.h>
+
+struct gpio_keys_button {
+	/* Configuration parameters */
+	int code;
+
+	int gpio;
+	int active_low;
+
+	/* internal */
+	int previous_state;
+};
+
+struct gpio_keys_platform_data {
+	struct gpio_keys_button *buttons;
+	int nbuttons;
+
+	/* optional */
+	int fifo_size;
+
+	struct kfifo *recv_fifo;
+	struct poller_struct poller;
+	struct console_device cdev;
+};
+
+#endif