[SeaBIOS] [PATCH 3/5] sdcard: Make sure controller support 3.3V before enabling it

[Kevin O'Connor]

Signed-off-by: Kevin O'Connor <kevin at koconnor.net>
---
 src/hw/sdcard.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/hw/sdcard.c b/src/hw/sdcard.c
index 57f44b0..d4dea6a 100644
--- a/src/hw/sdcard.c
+++ b/src/hw/sdcard.c
@@ -84,6 +84,7 @@ struct sdhci_s {
 #define ST_MULTIPLE   (1<<5)
 
 // SDHCI capabilities flags
+#define SD_CAPLO_V33             (1<<24)
 #define SD_CAPLO_BASECLOCK_SHIFT 8
 #define SD_CAPLO_BASECLOCK_MASK  0x3f
 
@@ -93,6 +94,10 @@ struct sdhci_s {
 #define SCC_CLOCK_ENABLE    (1<<2)
 #define SCC_SDCLK_SHIFT     8
 
+// SDHCI power control flags
+#define SPC_POWER_ON (1<<0)
+#define SPC_V33      0x0e
+
 // SDHCI result flags
 #define SR_OCR_CCS (1<<30)
 
@@ -274,6 +279,10 @@ sdcard_set_frequency(struct sdhci_s *regs, u32 khz)
         dprintf(1, "Unknown base frequency for SD controller\n");
         return -1;
     }
+    if (!(cap & SD_CAPLO_V33)) {
+        dprintf(1, "SD controller does not support 3.3V power\n");
+        return -1;
+    }
     // Set new frequency
     u32 divisor = DIV_ROUND_UP(base_freq * 1000, khz);
     divisor = divisor >= 1 ? 1 << (__ffs(divisor-1)+1) : 0;
@@ -315,7 +324,8 @@ sdcard_controller_setup(void *data)
     int ret = sdcard_set_frequency(regs, 400);
     if (ret)
         return;
-    writeb(&regs->power_control, 0x0f);
+    writeb(&regs->power_control, 0);
+    writeb(&regs->power_control, SPC_V33 | SPC_POWER_ON);
 
     // Initialize card
     int card_type = sdcard_card_setup(regs);
-- 
1.9.3