1 files changed, 132 insertions, 0 deletions
diff --git a/lib/utils/gpio/fdt_gpio.c b/lib/utils/gpio/fdt_gpio.c
new file mode 100644
index 0000000..bff391f
--- /dev/null
+++ b/lib/utils/gpio/fdt_gpio.c
@@ -0,0 +1,132 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Anup Patel <anup.patel@wdc.com>
+ */
+
+#include <libfdt.h>
+#include <sbi/sbi_error.h>
+#include <sbi_utils/fdt/fdt_helper.h>
+#include <sbi_utils/gpio/fdt_gpio.h>
+
+static struct fdt_gpio *gpio_drivers[] = {
+};
+
+static struct fdt_gpio *fdt_gpio_driver(struct gpio_chip *chip)
+{
+	int pos;
+
+	if (!chip)
+		return NULL;
+
+	for (pos = 0; pos < array_size(gpio_drivers); pos++) {
+		if (chip->driver == gpio_drivers[pos])
+			return gpio_drivers[pos];
+	}
+
+	return NULL;
+}
+
+static int fdt_gpio_init(void *fdt, u32 phandle)
+{
+	int pos, nodeoff, rc;
+	struct fdt_gpio *drv;
+	const struct fdt_match *match;
+
+	/* Find node offset */
+	nodeoff = fdt_node_offset_by_phandle(fdt, phandle);
+	if (nodeoff < 0)
+		return nodeoff;
+
+	/* Check "gpio-controller" property */
+	if (!fdt_getprop(fdt, nodeoff, "gpio-controller", &rc))
+		return SBI_EINVAL;
+
+	/* Try all GPIO drivers one-by-one */
+	for (pos = 0; pos < array_size(gpio_drivers); pos++) {
+		drv = gpio_drivers[pos];
+
+		match = fdt_match_node(fdt, nodeoff, drv->match_table);
+		if (match && drv->init) {
+			rc = drv->init(fdt, nodeoff, phandle, match);
+			if (rc == SBI_ENODEV)
+				continue;
+			if (rc)
+				return rc;
+			return 0;
+		}
+	}
+
+	return SBI_ENOSYS;
+}
+
+static int fdt_gpio_chip_find(void *fdt, u32 phandle,
+			      struct gpio_chip **out_chip)
+{
+	int rc;
+	struct gpio_chip *chip = gpio_chip_find(phandle);
+
+	if (!chip) {
+		/* GPIO chip not found so initialize matching driver */
+		rc = fdt_gpio_init(fdt, phandle);
+		if (rc)
+			return rc;
+
+		/* Try to find GPIO chip again */
+		chip = gpio_chip_find(phandle);
+		if (!chip)
+			return SBI_ENOSYS;
+	}
+
+	if (out_chip)
+		*out_chip = chip;
+
+	return 0;
+}
+
+int fdt_gpio_pin_get(void *fdt, int nodeoff, int index,
+		     struct gpio_pin *out_pin)
+{
+	int rc;
+	u32 phandle;
+	struct fdt_gpio *drv;
+	struct gpio_chip *chip = NULL;
+	struct fdt_phandle_args pargs;
+
+	if (!fdt || (nodeoff < 0) || (index < 0) || !out_pin)
+		return SBI_EINVAL;
+
+	pargs.node_offset = pargs.args_count = 0;
+	rc = fdt_parse_phandle_with_args(fdt, nodeoff,
+					 "gpios", "#gpio-cells",
+					 index, &pargs);
+	if (rc)
+		return rc;
+
+	phandle = fdt_get_phandle(fdt, pargs.node_offset);
+	rc = fdt_gpio_chip_find(fdt, phandle, &chip);
+	if (rc)
+		return rc;
+
+	drv = fdt_gpio_driver(chip);
+	if (!drv || !drv->xlate)
+		return SBI_ENOSYS;
+
+	return drv->xlate(chip, &pargs, out_pin);
+}
+
+int fdt_gpio_simple_xlate(struct gpio_chip *chip,
+			  const struct fdt_phandle_args *pargs,
+			  struct gpio_pin *out_pin)
+{
+	if ((pargs->args_count < 2) || (chip->ngpio <= pargs->args[0]))
+		return SBI_EINVAL;
+
+	out_pin->chip = chip;
+	out_pin->offset = pargs->args[0];
+	out_pin->flags = pargs->args[1];
+	return 0;
+}