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 <s...@chromium.org>
---
Changes in v2:
- Fix gpio_direction_output() to actually set the value
- Use generic GPIO command and interface
Changes in v3:
- Change GPIO numbers to unsigned as per new asm-generic/gpio.h
- Implement GPIO interface more fully (reservation, gpio state)
- Use __func__ when function names are required
Changes in v4:
- Add comments to clearly explain the purpose of the sandbox GPIO interface
arch/sandbox/include/asm/gpio.h | 81 ++++++++++++++++
drivers/gpio/Makefile | 1 +
drivers/gpio/sandbox.c | 194 +++++++++++++++++++++++++++++++++++++++
3 files changed, 276 insertions(+), 0 deletions(-)
create mode 100644 arch/sandbox/include/asm/gpio.h
create mode 100644 drivers/gpio/sandbox.c
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
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 4375a55..fb3b09a 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -34,6 +34,7 @@ COBJS-$(CONFIG_MXS_GPIO) += mxs_gpio.o
COBJS-$(CONFIG_PCA953X) += pca953x.o
COBJS-$(CONFIG_PCA9698) += pca9698.o
COBJS-$(CONFIG_S5P) += s5p_gpio.o
+COBJS-$(CONFIG_SANDBOX_GPIO) += sandbox.o
COBJS-$(CONFIG_TEGRA2_GPIO) += tegra2_gpio.o
COBJS-$(CONFIG_DA8XX_GPIO) += da8xx_gpio.o
COBJS-$(CONFIG_ALTERA_PIO) += altera_pio.o
diff --git a/drivers/gpio/sandbox.c b/drivers/gpio/sandbox.c
new file mode 100644
index 0000000..17e601d
--- /dev/null
+++ b/drivers/gpio/sandbox.c
@@ -0,0 +1,194 @@
+/*
+ * 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
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/bitops.h>
+#include <asm-generic/gpio.h>
+#include <asm/gpio.h>
+
+/* Flags for each GPIO */
+#define GPIOF_OUTPUT (1 << 0) /* Currently set as an output */
+#define GPIOF_HIGH (1 << 1) /* Currently set high */
+#define GPIOF_RESERVED (1 << 2) /* Is in use / requested */
+
+struct gpio_state {
+ const char *label; /* label given by requester */
+ u8 flags; /* flags (GPIOF_...) */
+};
+
+/*
+ * State of GPIOs
+ * TODO: Put this into sandbox state
+ */
+static struct gpio_state state[CONFIG_SANDBOX_GPIO_COUNT];
+
+/* Access routines for GPIO state */
+static u8 *get_gpio(unsigned gp)
+{
+ assert(gp < CONFIG_SANDBOX_GPIO_COUNT);
+ return &state[gp].flags;
+}
+
+static int get_gpio_flag(unsigned gp, int flag)
+{
+ return (*get_gpio(gp) & flag) != 0;
+}
+
+static void set_gpio_flag(unsigned gp, int flag, int value)
+{
+ u8 *gpio = get_gpio(gp);
+
+ if (value)
+ *gpio |= flag;
+ else
+ *gpio &= ~flag;
+}
+
+int sandbox_gpio_get_value(unsigned gp)
+{
+ if (get_gpio_flag(gp, GPIOF_OUTPUT))
+ printf("sandbox_gpio: get_value on output GPIO %d\n", gp);
+ return *get_gpio(gp) & GPIOF_HIGH;
+}
+
+int sandbox_gpio_set_value(unsigned gp, int value)
+{
+ set_gpio_flag(gp, GPIOF_HIGH, value);
+ return 0;
+}
+
+int sandbox_gpio_get_direction(unsigned gp)
+{
+ return get_gpio_flag(gp, GPIOF_OUTPUT);
+}
+
+int sandbox_gpio_set_direction(unsigned gp, int output)
+{
+ set_gpio_flag(gp, GPIOF_OUTPUT, output);
+ return 0;
+}
+
+static int check_reserved(unsigned gpio, const char *op_name)
+{
+ if (!get_gpio_flag(gpio, GPIOF_RESERVED)) {
+ printf("sandbox_gpio: '%s' on unreserved GPIO\n", op_name);
+ return -1;
+ }
+
+ return 0;
+}
+
+/* These functions implement the public interface within U-Boot */
+
+/* set GPIO port 'gp' as an input */
+int gpio_direction_input(unsigned gp)
+{
+ debug("%s: gp = %d\n", __func__, gp);
+ if (check_reserved(gp, __func__))
+ return -1;
+ set_gpio_flag(gp, GPIOF_OUTPUT, 0);
+
+ return 0;
+}
+
+/* set GPIO port 'gp' as an output, with polarity 'value' */
+int gpio_direction_output(unsigned gp, int value)
+{
+ debug("%s: gp = %d, value = %d\n", __func__, gp, value);
+ if (check_reserved(gp, __func__))
+ return -1;
+ set_gpio_flag(gp, GPIOF_OUTPUT, 1);
+ set_gpio_flag(gp, GPIOF_HIGH, value);
+
+ return 0;
+}
+
+/* read GPIO IN value of port 'gp' */
+int gpio_get_value(unsigned gp)
+{
+ debug("%s: gp = %d\n", __func__, gp);
+ if (check_reserved(gp, __func__))
+ return -1;
+ if (get_gpio_flag(gp, GPIOF_OUTPUT))
+ printf("sandbox_gpio: get_value on output GPIO %d\n", gp);
+
+ return get_gpio_flag(gp, GPIOF_HIGH);
+}
+
+/* write GPIO OUT value to port 'gp' */
+int gpio_set_value(unsigned gp, int value)
+{
+ debug("%s: gp = %d, value = %d\n", __func__, gp, value);
+ if (check_reserved(gp, __func__))
+ return -1;
+ if (get_gpio_flag(gp, GPIOF_OUTPUT)) {
+ set_gpio_flag(gp, GPIOF_HIGH, value);
+ } else {
+ printf("sandbox_gpio: set_value on input GPIO %d\n", gp);
+ return -1;
+ }
+
+ return 0;
+}
+
+int gpio_request(unsigned gp, const char *label)
+{
+ debug("%s: gp = %d, label= %s\n", __func__, gp, label);
+ if (get_gpio_flag(gp, GPIOF_RESERVED)) {
+ printf("sandbox_gpio: request on reserved GPIO\n");
+ return -1;
+ }
+ set_gpio_flag(gp, GPIOF_RESERVED, 1);
+ state[gp].label = label;
+
+ return 0;
+}
+
+int gpio_free(unsigned gp)
+{
+ debug("%s: gp = %d\n", __func__, gp);
+ if (check_reserved(gp, __func__))
+ return -1;
+ set_gpio_flag(gp, GPIOF_RESERVED, 0);
+ state[gp].label = NULL;
+
+ return 0;
+}
+
+/* Display GPIO information */
+void gpio_info(void)
+{
+ unsigned gpio;
+
+ printf("Sandbox GPIOs\n");
+
+ for (gpio = 0; gpio < CONFIG_SANDBOX_GPIO_COUNT; ++gpio) {
+ const char *label = state[gpio].label;
+
+ printf("%4d: %s: %d [%c] %s\n",
+ gpio,
+ get_gpio_flag(gpio, GPIOF_OUTPUT) ? "out" : " in",
+ get_gpio_flag(gpio, GPIOF_HIGH),
+ get_gpio_flag(gpio, GPIOF_RESERVED) ? 'x' : ' ',
+ label ? label : "");
+ }
+}
--
1.7.7.3
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