[PATCH v2 4/8] sunxi: board: Add PinePhone DT selection logic

[Samuel Holland]

There are two different publicly-released revisions of the PinePhone
hardware, versions 1.1 and 1.2; and they need different device trees.
Since some GPIO pins were rerouted, we can use that to distinguish
between them.

Acked-by: Maxime Ripard <mripard at kernel.org>
Reviewed-by: Andre Przywara <andre.przywara at arm.com>
Signed-off-by: Samuel Holland <samuel at sholland.org>
---
 arch/arm/mach-sunxi/Kconfig |  7 +++++++
 board/sunxi/board.c         | 21 +++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
index be0822bfb7d..8421f3b6854 100644
--- a/arch/arm/mach-sunxi/Kconfig
+++ b/arch/arm/mach-sunxi/Kconfig
@@ -1010,4 +1010,11 @@ config PINE64_DT_SELECTION
 	  option, the device tree selection code specific to Pine64 which
 	  utilizes the DRAM size will be enabled.
 
+config PINEPHONE_DT_SELECTION
+	bool "Enable PinePhone device tree selection code"
+	depends on MACH_SUN50I
+	help
+	  Enable this option to automatically select the device tree for the
+	  correct PinePhone hardware revision during boot.
+
 endif
diff --git a/board/sunxi/board.c b/board/sunxi/board.c
index ec1920c3a39..bff5135c1a1 100644
--- a/board/sunxi/board.c
+++ b/board/sunxi/board.c
@@ -27,6 +27,7 @@
 #include <asm/arch/dram.h>
 #include <asm/arch/gpio.h>
 #include <asm/arch/mmc.h>
+#include <asm/arch/prcm.h>
 #include <asm/arch/spl.h>
 #include <linux/delay.h>
 #include <u-boot/crc.h>
@@ -920,6 +921,26 @@ int board_fit_config_name_match(const char *name)
 			best_dt_name = "sun50i-a64-pine64";
 	}
 #endif
+#ifdef CONFIG_PINEPHONE_DT_SELECTION
+	if (strstr(best_dt_name, "-pinephone")) {
+		/* Differentiate the PinePhone revisions by GPIO inputs. */
+		prcm_apb0_enable(PRCM_APB0_GATE_PIO);
+		sunxi_gpio_set_pull(SUNXI_GPL(6), SUNXI_GPIO_PULL_UP);
+		sunxi_gpio_set_cfgpin(SUNXI_GPL(6), SUNXI_GPIO_INPUT);
+		udelay(100);
+
+		/* PL6 is pulled low by the modem on v1.2. */
+		if (gpio_get_value(SUNXI_GPL(6)) == 0)
+			best_dt_name = "sun50i-a64-pinephone-1.2";
+		else
+			best_dt_name = "sun50i-a64-pinephone-1.1";
+
+		sunxi_gpio_set_cfgpin(SUNXI_GPL(6), SUNXI_GPIO_DISABLE);
+		sunxi_gpio_set_pull(SUNXI_GPL(6), SUNXI_GPIO_PULL_DISABLE);
+		prcm_apb0_disable(PRCM_APB0_GATE_PIO);
+	}
+#endif
+
 	return strcmp(name, best_dt_name);
 }
 #endif
-- 
2.26.2