sandbox: gpio: add basic driver for simulating GPIOs

This provides a way of simulating GPIOs by setting values which are seen
by the normal gpio_get/set_value() calls.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 81 insertions, 0 deletions

diff --git a/arch/sandbox/include/asm/gpio.h b/arch/sandbox/include/asm/gpio.h
new file mode 100644
index 0000000..0500c53
--- /dev/null
+++ b/arch/sandbox/include/asm/gpio.h
@@ -0,0 +1,81 @@
+/*
+ * This is the interface to the sandbox GPIO driver for test code which
+ * wants to change the GPIO values reported to U-Boot.
+ *
+ * Copyright (c) 2011 The Chromium OS Authors.
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#ifndef __ASM_SANDBOX_GPIO_H
+#define __ASM_SANDBOX_GPIO_H
+
+/*
+ * We use the generic interface, and add a back-channel.
+ *
+ * The back-channel functions are declared in this file. They should not be used
+ * except in test code.
+ *
+ * Test code can, for example, call sandbox_gpio_set_value() to set the value of
+ * a simulated GPIO. From then on, normal code in U-Boot will see this new
+ * value when it calls gpio_get_value().
+ *
+ * NOTE: DO NOT use the functions in this file except in test code!
+ */
+#include <asm-generic/gpio.h>
+
+/**
+ * Return the simulated value of a GPIO (used only in sandbox test code)
+ *
+ * @param gp	GPIO number
+ * @return -1 on error, 0 if GPIO is low, >0 if high
+ */
+int sandbox_gpio_get_value(unsigned gp);
+
+/**
+ * Set the simulated value of a GPIO (used only in sandbox test code)
+ *
+ * @param gp	GPIO number
+ * @param value	value to set (0 for low, non-zero for high)
+ * @return -1 on error, 0 if ok
+ */
+int sandbox_gpio_set_value(unsigned gp, int value);
+
+/**
+ * Return the simulated direction of a GPIO (used only in sandbox test code)
+ *
+ * @param gp	GPIO number
+ * @return -1 on error, 0 if GPIO is input, >0 if output
+ */
+int sandbox_gpio_get_direction(unsigned gp);
+
+/**
+ * Set the simulated direction of a GPIO (used only in sandbox test code)
+ *
+ * @param gp	GPIO number
+ * @param output 0 to set as input, 1 to set as output
+ * @return -1 on error, 0 if ok
+ */
+int sandbox_gpio_set_direction(unsigned gp, int output);
+
+/* Display information about each GPIO */
+void gpio_info(void);
+
+#define gpio_status()	gpio_info()
+
+#endif