sdhci: implement UHS-I voltage switch

[based on a patch from Alistair Francis <alistair.francis@xilinx.com>
 from qemu/xilinx tag xilinx-v2015.2]
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alistair Francis <alistair.francis@xilinx.com>
Message-Id: <20180208164818.7961-22-f4bug@amsat.org>

4 files changed, 38 insertions, 1 deletions

diff --git a/hw/sd/core.c b/hw/sd/core.c
index 498284f109..6d198ea775 100644
--- a/hw/sd/core.c
+++ b/hw/sd/core.c
@@ -41,6 +41,19 @@ static SDState *get_card(SDBus *sdbus)
     return SD_CARD(kid->child);
 }
 
+void sdbus_set_voltage(SDBus *sdbus, uint16_t millivolts)
+{
+    SDState *card = get_card(sdbus);
+
+    trace_sdbus_set_voltage(sdbus_name(sdbus), millivolts);
+    if (card) {
+        SDCardClass *sc = SD_CARD_GET_CLASS(card);
+
+        assert(sc->set_voltage);
+        sc->set_voltage(card, millivolts);
+    }
+}
+
 int sdbus_do_command(SDBus *sdbus, SDRequest *req, uint8_t *response)
 {
     SDState *card = get_card(sdbus);
diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index 73e405a04f..a8d7a522c0 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -128,6 +128,18 @@ struct SDState {
     bool enable;
 };
 
+static void sd_set_voltage(SDState *sd, uint16_t millivolts)
+{
+    switch (millivolts) {
+    case 3001 ... 3600: /* SD_VOLTAGE_3_3V */
+    case 2001 ... 3000: /* SD_VOLTAGE_3_0V */
+        break;
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR, "SD card voltage not supported: %.3fV",
+                      millivolts / 1000.f);
+    }
+}
+
 static void sd_set_mode(SDState *sd)
 {
     switch (sd->state) {
@@ -1926,6 +1938,7 @@ static void sd_class_init(ObjectClass *klass, void *data)
     dc->reset = sd_reset;
     dc->bus_type = TYPE_SD_BUS;
 
+    sc->set_voltage = sd_set_voltage;
     sc->do_command = sd_do_command;
     sc->write_data = sd_write_data;
     sc->read_data = sd_read_data;
diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c
index 2712b8218a..5ca82cf301 100644
--- a/hw/sd/sdhci.c
+++ b/hw/sd/sdhci.c
@@ -1255,7 +1255,16 @@ sdhci_write(void *opaque, hwaddr offset, uint64_t val, unsigned size)
         sdhci_update_irq(s);
         break;
     case SDHC_ACMD12ERRSTS:
-        MASKED_WRITE(s->acmd12errsts, mask, value);
+        MASKED_WRITE(s->acmd12errsts, mask, value & UINT16_MAX);
+        if (s->uhs_mode >= UHS_I) {
+            MASKED_WRITE(s->hostctl2, mask >> 16, value >> 16);
+
+            if (FIELD_EX32(s->hostctl2, SDHC_HOSTCTL2, V18_ENA)) {
+                sdbus_set_voltage(&s->sdbus, SD_VOLTAGE_1_8V);
+            } else {
+                sdbus_set_voltage(&s->sdbus, SD_VOLTAGE_3_3V);
+            }
+        }
         break;
 
     case SDHC_CAPAB:
@@ -1310,6 +1319,7 @@ static void sdhci_init_readonly_registers(SDHCIState *s, Error **errp)
 
 #define DEFINE_SDHCI_COMMON_PROPERTIES(_state) \
     DEFINE_PROP_UINT8("sd-spec-version", _state, sd_spec_version, 2), \
+    DEFINE_PROP_UINT8("uhs", _state, uhs_mode, UHS_NOT_SUPPORTED), \
     \
     /* Capabilities registers provide information on supported
      * features of this specific host controller implementation */ \
diff --git a/hw/sd/trace-events b/hw/sd/trace-events
index ea2746c8b7..84d2f398b1 100644
--- a/hw/sd/trace-events
+++ b/hw/sd/trace-events
@@ -4,6 +4,7 @@
 sdbus_command(const char *bus_name, uint8_t cmd, uint32_t arg, uint8_t crc) "@%s CMD%02d arg 0x%08x crc 0x%02x"
 sdbus_read(const char *bus_name, uint8_t value) "@%s value 0x%02x"
 sdbus_write(const char *bus_name, uint8_t value) "@%s value 0x%02x"
+sdbus_set_voltage(const char *bus_name, uint16_t millivolts) "@%s %u (mV)"
 
 # hw/sd/sdhci.c
 sdhci_set_inserted(const char *level) "card state changed: %s"