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>

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);

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;

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 */ \

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"

include/hw/sd/sd.h

@@ -55,6 +55,20 @@
 #define AKE_SEQ_ERROR		(1 << 3)
 #define OCR_CCS_BITN        30
 
+typedef enum {
+    SD_VOLTAGE_0_4V     = 400,  /* currently not supported */
+    SD_VOLTAGE_1_8V     = 1800,
+    SD_VOLTAGE_3_0V     = 3000,
+    SD_VOLTAGE_3_3V     = 3300,
+} sd_voltage_mv_t;
+
+typedef enum  {
+    UHS_NOT_SUPPORTED   = 0,
+    UHS_I               = 1,
+    UHS_II              = 2,    /* currently not supported */
+    UHS_III             = 3,    /* currently not supported */
+} sd_uhs_mode_t;
+
 typedef enum {
     sd_none = -1,
     sd_bc = 0,	/* broadcast -- no response */
@@ -88,6 +102,7 @@ typedef struct {
     void (*write_data)(SDState *sd, uint8_t value);
     uint8_t (*read_data)(SDState *sd);
     bool (*data_ready)(SDState *sd);
+    void (*set_voltage)(SDState *sd, uint16_t millivolts);
     void (*enable)(SDState *sd, bool enable);
     bool (*get_inserted)(SDState *sd);
     bool (*get_readonly)(SDState *sd);
@@ -134,6 +149,7 @@ void sd_enable(SDState *sd, bool enable);
 /* Functions to be used by qdevified callers (working via
  * an SDBus rather than directly with SDState)
  */
+void sdbus_set_voltage(SDBus *sdbus, uint16_t millivolts);
 int sdbus_do_command(SDBus *sd, SDRequest *req, uint8_t *response);
 void sdbus_write_data(SDBus *sd, uint8_t value);
 uint8_t sdbus_read_data(SDBus *sd);

include/hw/sd/sdhci.h

@@ -96,6 +96,7 @@ typedef struct SDHCIState {
     bool pending_insert_quirk; /* Quirk for Raspberry Pi card insert int */
     uint32_t quirks;
     uint8_t sd_spec_version;
+    uint8_t uhs_mode;
 } SDHCIState;
 
 /*