1 files changed, 156 insertions, 0 deletions
diff --git a/drivers/misc/uart_select.c b/drivers/misc/uart_select.c
new file mode 100644
index 0000000..22d1439
--- /dev/null
+++ b/drivers/misc/uart_select.c
@@ -0,0 +1,156 @@
+/*
+ * uart_sel.c - UART Selection Driver
+ *
+ * Copyright (C) 2009 Samsung Electronics
+ * Kim Kyuwon <q1.kim@samsung.com>
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/gpio.h>
+#include <linux/uart_select.h>
+
+struct uart_select {
+	struct uart_select_platform_data	*pdata;
+	struct rw_semaphore			rwsem;
+};
+
+static int uart_saved_state = UART_SW_PATH_NA;
+
+static ssize_t uart_select_show_state(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct uart_select *uart_sel =
+			platform_get_drvdata(to_platform_device(dev));
+	int ret;
+	int path;
+
+	path = uart_sel->pdata->get_uart_switch();
+
+	down_read(&uart_sel->rwsem);
+	uart_saved_state = path;
+	if (path == UART_SW_PATH_NA)
+		ret = sprintf(buf, "NA\n");
+	else if (path == UART_SW_PATH_CP)
+		ret = sprintf(buf, "CP\n");
+	else
+		ret = sprintf(buf, "AP\n");
+	up_read(&uart_sel->rwsem);
+
+	return ret;
+}
+
+static ssize_t uart_select_store_state(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct uart_select *uart_sel =
+			platform_get_drvdata(to_platform_device(dev));
+	struct uart_select_platform_data *pdata = uart_sel->pdata;
+	int path;
+
+	if (!count)
+		return -EINVAL;
+
+	down_write(&uart_sel->rwsem);
+	if (!strncmp(buf, "CP", 2))
+		path = UART_SW_PATH_CP;
+	else if (!strncmp(buf, "AP", 2))
+		path = UART_SW_PATH_AP;
+	else {
+		up_write(&uart_sel->rwsem);
+		dev_err(dev, "Invalid cmd !!\n");
+		return -EINVAL;
+	}
+	pdata->set_uart_switch(path);
+	uart_saved_state = path;
+	up_write(&uart_sel->rwsem);
+
+	return count;
+}
+
+static struct device_attribute uart_select_attr = {
+	.attr = {
+		.name = "path",
+		.mode = 0644,
+	},
+	.show = uart_select_show_state,
+	.store = uart_select_store_state,
+};
+
+/* Used in uart isr to avoid triggering sysrq when uart is not in AP */
+int uart_sel_get_state(void)
+{
+	if (uart_saved_state < 0)
+		return -EPERM;
+	else
+		return uart_saved_state;
+}
+EXPORT_SYMBOL(uart_sel_get_state);
+
+static int __devinit uart_select_probe(struct platform_device *pdev)
+{
+	struct uart_select *uart_sel;
+	struct uart_select_platform_data *pdata = pdev->dev.platform_data;
+	int ret;
+
+	uart_sel = kzalloc(sizeof(struct uart_select), GFP_KERNEL);
+	if (!uart_sel) {
+		dev_err(&pdev->dev, "failed to allocate driver data\n");
+		return -ENOMEM;
+	}
+
+	platform_set_drvdata(pdev, uart_sel);
+	uart_sel->pdata = pdata;
+	init_rwsem(&uart_sel->rwsem);
+
+	uart_saved_state = pdata->get_uart_switch();
+
+	ret = device_create_file(&pdev->dev, &uart_select_attr);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to crreate device file\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int __devexit uart_select_remove(struct platform_device *pdev)
+{
+	device_remove_file(&pdev->dev, &uart_select_attr);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static struct platform_driver uart_select_driver = {
+	.probe		= uart_select_probe,
+	.remove		= __devexit_p(uart_select_remove),
+	.driver		= {
+		.name	= "uart-select",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init uart_select_init(void)
+{
+	return platform_driver_register(&uart_select_driver);
+}
+module_init(uart_select_init);
+
+static void __exit uart_select_exit(void)
+{
+	platform_driver_unregister(&uart_select_driver);
+}
+module_exit(uart_select_exit);
+
+MODULE_AUTHOR("Kim Kyuwon <q1.kim@samsung.com>");
+MODULE_DESCRIPTION("UART Selection Driver");
+MODULE_LICENSE("GPL v2");