[U-Boot] [PATCH 1/6] sunxi: GPIO: introduce sunxi_gpio_setup_dt_pins()

[Andre Przywara <andre.przywara@arm.com>]

Instead of hard-coding GPIO pins used for a certain peripheral, we
should just use the pinctrl information from the DT.
The sun8i-emac driver has some simple implementation of that, so
let's just generalize this and move the code into a more common
location.
On the way we add support for the new, generic pinctrl binding now
used by all Allwinner SoCs.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
 arch/arm/include/asm/arch-sunxi/gpio.h |  4 ++
 arch/arm/mach-sunxi/pinmux.c           | 77 ++++++++++++++++++++++++++++++++++
 2 files changed, 81 insertions(+)

diff --git a/arch/arm/include/asm/arch-sunxi/gpio.h b/arch/arm/include/asm/arch-sunxi/gpio.h
index 85a4ec3..ba8c661 100644
--- a/arch/arm/include/asm/arch-sunxi/gpio.h
+++ b/arch/arm/include/asm/arch-sunxi/gpio.h
@@ -239,4 +239,8 @@ int axp_gpio_init(void);
 static inline int axp_gpio_init(void) { return 0; }
 #endif
 
+int sunxi_gpio_parse_pin_name(const char *pin_name);
+int sunxi_gpio_setup_dt_pins(const void * volatile fdt_blob, int node,
+			     const char * mux_name, int mux_sel);
+
 #endif /* _SUNXI_GPIO_H */
diff --git a/arch/arm/mach-sunxi/pinmux.c b/arch/arm/mach-sunxi/pinmux.c
index b026f78..f1e1e8f 100644
--- a/arch/arm/mach-sunxi/pinmux.c
+++ b/arch/arm/mach-sunxi/pinmux.c
@@ -9,6 +9,9 @@
 #include <common.h>
 #include <asm/io.h>
 #include <asm/arch/gpio.h>
+#include <fdtdec.h>
+#include <fdt_support.h>
+#include <dt-bindings/pinctrl/sun4i-a10.h>
 
 void sunxi_gpio_set_cfgbank(struct sunxi_gpio *pio, int bank_offset, u32 val)
 {
@@ -69,3 +72,77 @@ int sunxi_gpio_set_pull(u32 pin, u32 val)
 
 	return 0;
 }
+
+int sunxi_gpio_parse_pin_name(const char *pin_name)
+{
+	int pin;
+
+	if (pin_name[0] != 'P')
+		return -1;
+
+	if (pin_name[1] < 'A' || pin_name[1] > 'Z')
+		return -1;
+
+	pin = (pin_name[1] - 'A') << 5;
+	pin += simple_strtol(&pin_name[2], NULL, 10);
+
+	return pin;
+}
+
+int sunxi_gpio_setup_dt_pins(const void * volatile fdt_blob, int node,
+			     const char * mux_name, int mux_sel)
+{
+	int drive, pull, pin, i;
+	const char *pin_name;
+	int offset;
+
+	offset = fdtdec_lookup_phandle(fdt_blob, node, "pinctrl-0");
+	if (offset < 0)
+		return offset;
+
+	drive = fdt_getprop_u32_default_node(fdt_blob, offset, 0,
+					     "drive-strength", 0);
+	if (drive) {
+		if (drive <= 10)
+			drive = SUN4I_PINCTRL_10_MA;
+		else if (drive <= 20)
+			drive = SUN4I_PINCTRL_20_MA;
+		else if (drive <= 30)
+			drive = SUN4I_PINCTRL_30_MA;
+		else
+			drive = SUN4I_PINCTRL_40_MA;
+	} else {
+		drive = fdt_getprop_u32_default_node(fdt_blob, offset, 0,
+						     "allwinner,drive", 4);
+	}
+
+	if (fdt_get_property(fdt_blob, offset, "bias-pull-up", NULL))
+		pull = SUN4I_PINCTRL_PULL_UP;
+	else if (fdt_get_property(fdt_blob, offset, "bias-disable", NULL))
+		pull = SUN4I_PINCTRL_NO_PULL;
+	else if (fdt_get_property(fdt_blob, offset, "bias-pull-down", NULL))
+		pull = SUN4I_PINCTRL_PULL_DOWN;
+	else
+		pull = fdt_getprop_u32_default_node(fdt_blob, offset, 0,
+						    "allwinner,pull", 0);
+
+	for (i = 0; ; i++) {
+		pin_name = fdt_stringlist_get(fdt_blob, offset,
+					      "allwinner,pins", i, NULL);
+		if (!pin_name) {
+			pin_name = fdt_stringlist_get(fdt_blob, offset,
+						      "pins", i, NULL);
+			if (!pin_name)
+				break;
+		}
+		pin = sunxi_gpio_parse_pin_name(pin_name);
+		if (pin < 0)
+			continue;
+
+		sunxi_gpio_set_cfgpin(pin, mux_sel);
+		sunxi_gpio_set_drv(pin, drive);
+		sunxi_gpio_set_pull(pin, pull);
+	}
+
+	return i;
+}
-- 
2.8.2