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>
---
 drivers/gpio/Makefile  |    1 +
 drivers/gpio/sandbox.c |  213 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/sandbox_gpio.h |   50 +++++++++++
 3 files changed, 264 insertions(+), 0 deletions(-)
 create mode 100644 drivers/gpio/sandbox.c
 create mode 100644 include/sandbox_gpio.h

diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index f505813..f427127 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -33,6 +33,7 @@ COBJS-$(CONFIG_MXC_GPIO)      += mxc_gpio.o
 COBJS-$(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
 
diff --git a/drivers/gpio/sandbox.c b/drivers/gpio/sandbox.c
new file mode 100644
index 0000000..81ba803
--- /dev/null
+++ b/drivers/gpio/sandbox.c
@@ -0,0 +1,213 @@
+/*
+ * 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/arch/gpio.h>
+
+enum {
+       CMD_INFO,
+       CMD_PORT,
+       CMD_OUTPUT,
+       CMD_INPUT,
+};
+
+/* Flags for each GPIO */
+enum {
+       GPIOF_OUTPUT    = 1 << 1,
+       GPIOF_HIGH      = 1 << 2,
+};
+
+/* TODO: Put this into sandbox state */
+static u8 state[GPIO_COUNT];   /* State of GPIOs */
+
+
+/* Access routines for GPIO state */
+static u8 *get_gpio(int gp)
+{
+       assert(gp >= 0 && gp < GPIO_COUNT);
+       return &state[gp];
+}
+
+static int get_gpio_flag(int gp, int flag)
+{
+       return *get_gpio(gp) & flag;
+}
+
+static void set_gpio_flag(int gp, int flag, int value)
+{
+       u8 *gpio = get_gpio(gp);
+
+       if (value)
+               *gpio |= flag;
+       else
+               *gpio &= ~flag;
+}
+
+int sandbox_gpio_get_value(int 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(int gp, int value)
+{
+       set_gpio_flag(gp, GPIOF_HIGH, value);
+       return 0;
+}
+
+int sandbox_gpio_get_direction(int gp)
+{
+       return get_gpio_flag(gp, GPIOF_OUTPUT);
+}
+
+int sandbox_gpio_set_direction(int gp, int output)
+{
+       set_gpio_flag(gp, GPIOF_OUTPUT, output);
+       return 0;
+}
+
+
+/* These functions make up what could be a public interface within U-Boot */
+
+/* set GPIO port 'gp' as an input */
+int gpio_direction_input(int gp)
+{
+       debug("gpio_direction_input: gp = %d\n", gp);
+       set_gpio_flag(gp, GPIOF_OUTPUT, 0);
+       return 0;
+}
+
+/* set GPIO port 'gp' as an output, with polarity 'value' */
+int gpio_direction_output(int gp, int value)
+{
+       debug("gpio_direction_output: gp = %d, value = %d\n",
+             gp, value);
+       set_gpio_flag(gp, GPIOF_OUTPUT, 1);
+       return 0;
+}
+
+/* read GPIO IN value of port 'gp' */
+int gpio_get_value(int gp)
+{
+       debug("gpio_get_value: gp = %d\n", 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;
+}
+
+/* write GPIO OUT value to port 'gp' */
+void gpio_set_value(int gp, int value)
+{
+       debug("gpio_set_value: gp = %d, value = %d\n", gp, value);
+       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);
+}
+
+/* Display GPIO information */
+static int gpio_info(int gp)
+{
+       printf("Sandbox GPIOs\n");
+       return 0;
+}
+
+cmd_tbl_t cmd_gpio[] = {
+       U_BOOT_CMD_MKENT(offset2port, 3, 0, (void *)CMD_PORT, "", ""),
+       U_BOOT_CMD_MKENT(output, 4, 0, (void *)CMD_OUTPUT, "", ""),
+       U_BOOT_CMD_MKENT(input, 3, 0, (void *)CMD_INPUT, "", ""),
+#ifdef CONFIG_CMD_GPIO_INFO
+       U_BOOT_CMD_MKENT(info, 3, 0, (void *)CMD_INFO, "", ""),
+#endif
+};
+
+int do_gpio(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+       static uint8_t offset;
+       int val __attribute__((unused));
+       ulong ul_arg2, ul_arg3, ul_arg4;
+       cmd_tbl_t *c;
+
+       ul_arg2 = ul_arg3 = ul_arg4 = 0;
+
+       c = find_cmd_tbl(argv[1], cmd_gpio, ARRAY_SIZE(cmd_gpio));
+
+       /* All commands but "port" require 'maxargs' arguments */
+       if (!c || !((argc == (c->maxargs)) ||
+               (((long)c->cmd == CMD_PORT) &&
+                (argc == (c->maxargs - 1))))) {
+               cmd_usage(cmdtp);
+               return 1;
+       }
+
+       /* arg2 used as offset */
+       if (argc > 2)
+               ul_arg2 = simple_strtoul(argv[2], NULL, 10);
+
+       /* arg3 used as output value, 0 or 1 */
+       if (argc > 3)
+               ul_arg3 = simple_strtoul(argv[3], NULL, 10) & 0x1;
+
+       switch ((long)c->cmd) {
+       case CMD_INFO:
+               if (argc == 3)
+                       offset = (uint8_t)ul_arg2;
+               return gpio_info(offset);
+
+       case CMD_PORT:
+               if (argc == 3)
+                       offset = (uint8_t)ul_arg2;
+               return 0;
+
+       case CMD_INPUT:
+               /* arg2 = offset */
+               gpio_direction_input(ul_arg2);
+               val = gpio_get_value(ul_arg2);
+               return 0;
+
+       case CMD_OUTPUT:
+               /* args = offset, value */
+               gpio_direction_output(ul_arg2, ul_arg3);
+               return 0;
+
+       default:
+               /* We should never get here */
+               return 1;
+       }
+}
+
+U_BOOT_CMD(
+       gpio,   5,      1,      do_gpio,
+       "GPIO access",
+       "offset2port offset\n"
+       "       - show GPIO port:bit based on 'offset'\n"
+#ifdef CONFIG_CMD_GPIO_INFO
+       "     info offset\n"
+       "       - display info for all bits in port based on 'offset'\n"
+#endif
+       "     output offset 0|1\n"
+       "       - using 'offset', set port:bit as output and drive low or 
high\n"
+       "     input offset\n"
+       "       - using 'offset', set port:bit as input and read value"
+);
diff --git a/include/sandbox_gpio.h b/include/sandbox_gpio.h
new file mode 100644
index 0000000..db92f7b
--- /dev/null
+++ b/include/sandbox_gpio.h
@@ -0,0 +1,50 @@
+/*
+ * 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
+ */
+
+/**
+ * Return the value of a GPIO
+ *
+ * @param gp   GPIO number
+ * @return -1 on error, 0 if GPIO is low, >0 if high
+ */
+int sandbox_gpio_get_value(int gp);
+
+/**
+ * @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(int gp, int value);
+
+/**
+ * Return the direction of a GPIO
+ *
+ * @param gp   GPIO number
+ * @return -1 on error, 0 if GPIO is input, >0 if output
+ */
+int sandbox_gpio_get_direction(int gp);
+
+/**
+ * @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(int gp, int output);
-- 
1.7.3.1

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