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path: root/drivers/gpio/bcm2835_gpio.c
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Diffstat (limited to 'drivers/gpio/bcm2835_gpio.c')
-rw-r--r--drivers/gpio/bcm2835_gpio.c89
1 files changed, 89 insertions, 0 deletions
diff --git a/drivers/gpio/bcm2835_gpio.c b/drivers/gpio/bcm2835_gpio.c
new file mode 100644
index 0000000..1d50dbd
--- /dev/null
+++ b/drivers/gpio/bcm2835_gpio.c
@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2012 Vikram Narayananan
+ * <vikram186@gmail.com>
+ *
+ * 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.
+ */
+
+#include <common.h>
+#include <asm/gpio.h>
+#include <asm/io.h>
+
+inline int gpio_is_valid(unsigned gpio)
+{
+ return (gpio < BCM2835_GPIO_COUNT);
+}
+
+int gpio_request(unsigned gpio, const char *label)
+{
+ return !gpio_is_valid(gpio);
+}
+
+int gpio_free(unsigned gpio)
+{
+ return 0;
+}
+
+int gpio_direction_input(unsigned gpio)
+{
+ struct bcm2835_gpio_regs *reg =
+ (struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE;
+ unsigned val;
+
+ val = readl(&reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
+ val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio));
+ val |= (BCM2835_GPIO_INPUT << BCM2835_GPIO_FSEL_SHIFT(gpio));
+ writel(val, &reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
+
+ return 0;
+}
+
+int gpio_direction_output(unsigned gpio, int value)
+{
+ struct bcm2835_gpio_regs *reg =
+ (struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE;
+ unsigned val;
+
+ gpio_set_value(gpio, value);
+
+ val = readl(&reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
+ val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio));
+ val |= (BCM2835_GPIO_OUTPUT << BCM2835_GPIO_FSEL_SHIFT(gpio));
+ writel(val, &reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
+
+ return 0;
+}
+
+int gpio_get_value(unsigned gpio)
+{
+ struct bcm2835_gpio_regs *reg =
+ (struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE;
+ unsigned val;
+
+ val = readl(&reg->gplev[BCM2835_GPIO_COMMON_BANK(gpio)]);
+
+ return (val >> BCM2835_GPIO_COMMON_SHIFT(gpio)) & 0x1;
+}
+
+int gpio_set_value(unsigned gpio, int value)
+{
+ struct bcm2835_gpio_regs *reg =
+ (struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE;
+ u32 *output_reg = value ? reg->gpset : reg->gpclr;
+
+ writel(1 << BCM2835_GPIO_COMMON_SHIFT(gpio),
+ &output_reg[BCM2835_GPIO_COMMON_BANK(gpio)]);
+
+ return 0;
+}