[U-Boot] [PATCH v3 3/3] rockchip: check download key before bootup

[Andy Yan <andy.yan@rock-chips.com>]

Enter download mode if the download key pressed.

Signed-off-by: Andy Yan <andy.yan@rock-chips.com>

---

Changes in v3: None
Changes in v2:
- more document
- move adc key detect as the default

 arch/arm/mach-rockchip/boot_mode.c | 43 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/arch/arm/mach-rockchip/boot_mode.c b/arch/arm/mach-rockchip/boot_mode.c
index 4652490..bf0a410 100644
--- a/arch/arm/mach-rockchip/boot_mode.c
+++ b/arch/arm/mach-rockchip/boot_mode.c
@@ -5,14 +5,57 @@
  */
 
 #include <common.h>
+#include <adc.h>
 #include <asm/io.h>
 #include <asm/arch/boot_mode.h>
 
+void set_back_to_bootrom_dnl_flag(void)
+{
+	writel(BOOT_BROM_DOWNLOAD, CONFIG_ROCKCHIP_BOOT_MODE_REG);
+}
+
+/*
+ * detect download key status by adc, most rockchip
+ * based boards use adc sample the download key status,
+ * but there are also some use gpio. So it's better to
+ * make this a weak function that can be override by
+ * some special boards.
+ */
+#define KEY_DOWN_MIN_VAL	0
+#define KEY_DOWN_MAX_VAL	30
+
+__weak int rockchip_dnl_key_pressed(void)
+{
+	unsigned int val;
+
+	if (adc_channel_single_shot("saradc", 1, &val)) {
+		printf("%s adc_channel_single_shot fail!\n", __func__);
+		return false;
+	}
+
+	if ((val >= KEY_DOWN_MIN_VAL) && (val <= KEY_DOWN_MAX_VAL))
+		return true;
+	else
+		return false;
+}
+
+void rockchip_dnl_mode_check(void)
+{
+	if (rockchip_dnl_key_pressed()) {
+		printf("download key pressed, entering download mode...");
+		set_back_to_bootrom_dnl_flag();
+		do_reset(NULL, 0, 0, NULL);
+	}
+}
+
 int setup_boot_mode(void)
 {
 	void *reg = (void *)CONFIG_ROCKCHIP_BOOT_MODE_REG;
 	int boot_mode = readl(reg);
 
+	rockchip_dnl_mode_check();
+
+	boot_mode = readl(reg);
 	debug("boot mode %x.\n", boot_mode);
 
 	/* Clear boot mode */
-- 
2.7.4