[PATCH 4/4] board: rockchip: Add early ADC button detect for RGxx3
Chris Morgan
macroalpha82 at gmail.com
Mon Feb 5 19:58:55 CET 2024
From: Chris Morgan <macromorgan at hotmail.com>
Add ADC button detect for early SPL stage for RGxx3 device. This is
important because on at least the RG353P and RG353V a clk pin is not
exposed that would allow us to take the eMMC out of the boot path.
Signed-off-by: Chris Morgan <macromorgan at hotmail.com>
---
board/anbernic/rgxx3_rk3566/rgxx3-rk3566.c | 64 ++++++++++++++++++++++
1 file changed, 64 insertions(+)
diff --git a/board/anbernic/rgxx3_rk3566/rgxx3-rk3566.c b/board/anbernic/rgxx3_rk3566/rgxx3-rk3566.c
index 5c57b902d1..099eea60c3 100644
--- a/board/anbernic/rgxx3_rk3566/rgxx3-rk3566.c
+++ b/board/anbernic/rgxx3_rk3566/rgxx3-rk3566.c
@@ -6,12 +6,14 @@
#include <abuf.h>
#include <adc.h>
#include <asm/io.h>
+#include <command.h>
#include <display.h>
#include <dm.h>
#include <dm/lists.h>
#include <env.h>
#include <fdt_support.h>
#include <linux/delay.h>
+#include <linux/iopoll.h>
#include <mipi_dsi.h>
#include <mmc.h>
#include <panel.h>
@@ -19,6 +21,8 @@
#include <stdlib.h>
#include <video_bridge.h>
+#define BOOT_BROM_DOWNLOAD 0xef08a53c
+
#define GPIO0_BASE 0xfdd60000
#define GPIO4_BASE 0xfe770000
#define GPIO_SWPORT_DR_L 0x0000
@@ -32,6 +36,14 @@
#define GPIO_WRITEMASK(bits) ((bits) << 16)
+#define SARADC_BASE 0xfe720000
+#define SARADC_DATA 0x0000
+#define SARADC_STAS 0x0004
+#define SARADC_ADC_STATUS BIT(0)
+#define SARADC_CTRL 0x0008
+#define SARADC_INPUT_SRC_MSK 0x7
+#define SARADC_POWER_CTRL BIT(3)
+
#define DTB_DIR "rockchip/"
struct rg3xx_model {
@@ -157,12 +169,64 @@ static const struct rg353_panel rg353_panel_details[] = {
},
};
+/*
+ * The device has internal eMMC, and while some devices have an exposed
+ * clk pin you can ground to force a bypass not all devices do. As a
+ * result it may be possible for some devices to become a perma-brick
+ * if a corrupted TPL or SPL stage with a valid header is flashed to
+ * the internal eMMC. Add functionality to read ADC channel 0 (the func
+ * button) as early as possible in the boot process to provide some
+ * protection against this. If we ever get an open TPL stage, we should
+ * consider moving this function there.
+ */
+void read_func_button(void)
+{
+ int ret;
+ u32 reg;
+
+ /* Turn off SARADC to reset it. */
+ writel(0, (SARADC_BASE + SARADC_CTRL));
+
+ /* Enable channel 0 and power on SARADC. */
+ writel(((0 & SARADC_INPUT_SRC_MSK) | SARADC_POWER_CTRL),
+ (SARADC_BASE + SARADC_CTRL));
+
+ /*
+ * Wait for data to be ready. Use timeout of 20000us from
+ * rockchip_saradc driver.
+ */
+ ret = readl_poll_timeout((SARADC_BASE + SARADC_STAS), reg,
+ !(reg & SARADC_ADC_STATUS), 20000);
+ if (ret) {
+ printf("ADC Timeout");
+ return;
+ }
+
+ /* Read the data from the SARADC. */
+ reg = readl((SARADC_BASE + SARADC_DATA));
+
+ /* Turn the SARADC back off so it's ready to be used again. */
+ writel(0, (SARADC_BASE + SARADC_CTRL));
+
+ /*
+ * If the value is less than 30 the button is being pressed.
+ * Reset the device back into Rockchip download mode.
+ */
+ if (reg <= 30) {
+ printf("download key pressed, entering download mode...");
+ writel(BOOT_BROM_DOWNLOAD, CONFIG_ROCKCHIP_BOOT_MODE_REG);
+ do_reset(NULL, 0, 0, NULL);
+ }
+};
+
/*
* Start LED very early so user knows device is on. Set color
* to red.
*/
void spl_board_init(void)
{
+ read_func_button();
+
/* Set GPIO0_C5, GPIO0_C6, and GPIO0_C7 to output. */
writel(GPIO_WRITEMASK(GPIO_C7 | GPIO_C6 | GPIO_C5) | \
(GPIO_C7 | GPIO_C6 | GPIO_C5),
--
2.34.1
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