am335x: Add some code for manipulating GPIOs

Add code for manipulating the GPIOs on the am335x. The API is patterned after
the one used for the Exynos SOCs.

Change-Id: I275317304bd0682f348f72f1c77ed5613065af3f
Signed-off-by: Gabe Black <gabeblack@chromium.org>
Reviewed-on: https://review.coreboot.org/3942
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

1 files changed, 89 insertions, 0 deletions

diff --git a/src/cpu/ti/am335x/gpio.c b/src/cpu/ti/am335x/gpio.c
new file mode 100644
index 0000000000..d4f7edfb72
--- /dev/null
+++ b/src/cpu/ti/am335x/gpio.c
@@ -0,0 +1,89 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * 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 <arch/io.h>
+#include <console/console.h>
+#include <cpu/ti/am335x/gpio.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+static struct am335x_gpio_regs *gpio_regs_and_bit(unsigned gpio, uint32_t *bit)
+{
+	unsigned bank = gpio / AM335X_GPIO_BITS_PER_BANK;
+
+	if (bank > ARRAY_SIZE(am335x_gpio_banks)) {
+		printk(BIOS_ERR, "Bad gpio index %d.\n", gpio);
+		return NULL;
+	}
+	*bit = 1 << (gpio % 32);
+	return am335x_gpio_banks[bank];
+}
+
+void am335x_disable_gpio_irqs(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(am335x_gpio_banks); i++)
+		write32(&am335x_gpio_banks[i]->irqstatus_clr_0, 0xffffffff);
+}
+
+int gpio_direction_input(unsigned gpio)
+{
+	uint32_t bit;
+	struct am335x_gpio_regs *regs = gpio_regs_and_bit(gpio, &bit);
+
+	if (!regs)
+		return -1;
+	setbits_le32(&regs->oe, bit);
+	return 0;
+}
+
+int gpio_direction_output(unsigned gpio, int value)
+{
+	uint32_t bit;
+	struct am335x_gpio_regs *regs = gpio_regs_and_bit(gpio, &bit);
+
+	if (!regs)
+		return -1;
+	if (value)
+		write32(&regs->setdataout, bit);
+	else
+		write32(&regs->cleardataout, bit);
+	clrbits_le32(&regs->oe, bit);
+	return 0;
+}
+
+int gpio_get_value(unsigned gpio)
+{
+	uint32_t bit;
+	struct am335x_gpio_regs *regs = gpio_regs_and_bit(gpio, &bit);
+
+	if (!regs)
+		return -1;
+	return (read32(&regs->datain) & bit) ? 1 : 0;
+}
+
+int gpio_set_value(unsigned gpio, int value)
+{
+	uint32_t bit;
+	struct am335x_gpio_regs *regs = gpio_regs_and_bit(gpio, &bit);
+
+	if (!regs)
+		return -1;
+	if (value)
+		write32(&regs->setdataout, bit);
+	else
+		write32(&regs->cleardataout, bit);
+	return 0;
+}