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path: root/drivers/arm/pl061/pl061_gpio.c
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-rw-r--r--drivers/arm/pl061/pl061_gpio.c142
1 files changed, 142 insertions, 0 deletions
diff --git a/drivers/arm/pl061/pl061_gpio.c b/drivers/arm/pl061/pl061_gpio.c
new file mode 100644
index 0000000..97013e8
--- /dev/null
+++ b/drivers/arm/pl061/pl061_gpio.c
@@ -0,0 +1,142 @@
+/*
+ * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * ARM PL061 GPIO Driver.
+ * Reference to ARM DDI 0190B document.
+ *
+ */
+
+#include <assert.h>
+#include <errno.h>
+
+#include <common/debug.h>
+#include <drivers/arm/pl061_gpio.h>
+#include <drivers/gpio.h>
+#include <lib/cassert.h>
+#include <lib/mmio.h>
+#include <lib/utils.h>
+
+#if !PLAT_PL061_MAX_GPIOS
+# define PLAT_PL061_MAX_GPIOS 32
+#endif /* PLAT_PL061_MAX_GPIOS */
+
+CASSERT(PLAT_PL061_MAX_GPIOS > 0, assert_plat_pl061_max_gpios);
+
+#define MAX_GPIO_DEVICES ((PLAT_PL061_MAX_GPIOS + \
+ (GPIOS_PER_PL061 - 1)) / GPIOS_PER_PL061)
+
+#define PL061_GPIO_DIR 0x400
+
+#define GPIOS_PER_PL061 8
+
+static int pl061_get_direction(int gpio);
+static void pl061_set_direction(int gpio, int direction);
+static int pl061_get_value(int gpio);
+static void pl061_set_value(int gpio, int value);
+
+static uintptr_t pl061_reg_base[MAX_GPIO_DEVICES];
+
+static const gpio_ops_t pl061_gpio_ops = {
+ .get_direction = pl061_get_direction,
+ .set_direction = pl061_set_direction,
+ .get_value = pl061_get_value,
+ .set_value = pl061_set_value,
+};
+
+static int pl061_get_direction(int gpio)
+{
+ uintptr_t base_addr;
+ unsigned int data, offset;
+
+ assert((gpio >= 0) && (gpio < PLAT_PL061_MAX_GPIOS));
+
+ base_addr = pl061_reg_base[gpio / GPIOS_PER_PL061];
+ offset = gpio % GPIOS_PER_PL061;
+ data = mmio_read_8(base_addr + PL061_GPIO_DIR);
+ if (data & BIT(offset))
+ return GPIO_DIR_OUT;
+ return GPIO_DIR_IN;
+}
+
+static void pl061_set_direction(int gpio, int direction)
+{
+ uintptr_t base_addr;
+ unsigned int data, offset;
+
+ assert((gpio >= 0) && (gpio < PLAT_PL061_MAX_GPIOS));
+
+ base_addr = pl061_reg_base[gpio / GPIOS_PER_PL061];
+ offset = gpio % GPIOS_PER_PL061;
+ if (direction == GPIO_DIR_OUT) {
+ data = mmio_read_8(base_addr + PL061_GPIO_DIR) | BIT(offset);
+ mmio_write_8(base_addr + PL061_GPIO_DIR, data);
+ } else {
+ data = mmio_read_8(base_addr + PL061_GPIO_DIR) & ~BIT(offset);
+ mmio_write_8(base_addr + PL061_GPIO_DIR, data);
+ }
+}
+
+/*
+ * The offset of GPIODATA register is 0.
+ * The values read from GPIODATA are determined for each bit, by the mask bit
+ * derived from the address used to access the data register, PADDR[9:2].
+ * Bits that are 1 in the address mask cause the corresponding bits in GPIODATA
+ * to be read, and bits that are 0 in the address mask cause the corresponding
+ * bits in GPIODATA to be read as 0, regardless of their value.
+ */
+static int pl061_get_value(int gpio)
+{
+ uintptr_t base_addr;
+ unsigned int offset;
+
+ assert((gpio >= 0) && (gpio < PLAT_PL061_MAX_GPIOS));
+
+ base_addr = pl061_reg_base[gpio / GPIOS_PER_PL061];
+ offset = gpio % GPIOS_PER_PL061;
+ if (mmio_read_8(base_addr + BIT(offset + 2)))
+ return GPIO_LEVEL_HIGH;
+ return GPIO_LEVEL_LOW;
+}
+
+/*
+ * In order to write GPIODATA, the corresponding bits in the mask, resulting
+ * from the address bus, PADDR[9:2], must be HIGH. Otherwise the bit values
+ * remain unchanged by the write.
+ */
+static void pl061_set_value(int gpio, int value)
+{
+ uintptr_t base_addr;
+ int offset;
+
+ assert((gpio >= 0) && (gpio < PLAT_PL061_MAX_GPIOS));
+
+ base_addr = pl061_reg_base[gpio / GPIOS_PER_PL061];
+ offset = gpio % GPIOS_PER_PL061;
+ if (value == GPIO_LEVEL_HIGH)
+ mmio_write_8(base_addr + BIT(offset + 2), BIT(offset));
+ else
+ mmio_write_8(base_addr + BIT(offset + 2), 0);
+}
+
+
+/*
+ * Register the PL061 GPIO controller with a base address and the offset
+ * of start pin in this GPIO controller.
+ * This function is called after pl061_gpio_ops_init().
+ */
+void pl061_gpio_register(uintptr_t base_addr, int gpio_dev)
+{
+ assert((gpio_dev >= 0) && (gpio_dev < MAX_GPIO_DEVICES));
+
+ pl061_reg_base[gpio_dev] = base_addr;
+}
+
+/*
+ * Initialize PL061 GPIO controller with the total GPIO numbers in SoC.
+ */
+void pl061_gpio_init(void)
+{
+ gpio_init(&pl061_gpio_ops);
+}