sdhci: implement CMD/DAT[] fields in the Present State register

[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: <20180208164818.7961-23-f4bug@amsat.org>

hw/sd/core.c

@@ -41,6 +41,40 @@ static SDState *get_card(SDBus *sdbus)
     return SD_CARD(kid->child);
 }
 
+uint8_t sdbus_get_dat_lines(SDBus *sdbus)
+{
+    SDState *slave = get_card(sdbus);
+    uint8_t dat_lines = 0b1111; /* 4 bit bus width */
+
+    if (slave) {
+        SDCardClass *sc = SD_CARD_GET_CLASS(slave);
+
+        if (sc->get_dat_lines) {
+            dat_lines = sc->get_dat_lines(slave);
+        }
+    }
+    trace_sdbus_get_dat_lines(sdbus_name(sdbus), dat_lines);
+
+    return dat_lines;
+}
+
+bool sdbus_get_cmd_line(SDBus *sdbus)
+{
+    SDState *slave = get_card(sdbus);
+    bool cmd_line = true;
+
+    if (slave) {
+        SDCardClass *sc = SD_CARD_GET_CLASS(slave);
+
+        if (sc->get_cmd_line) {
+            cmd_line = sc->get_cmd_line(slave);
+        }
+    }
+    trace_sdbus_get_cmd_line(sdbus_name(sdbus), cmd_line);
+
+    return cmd_line;
+}
+
 void sdbus_set_voltage(SDBus *sdbus, uint16_t millivolts)
 {
     SDState *card = get_card(sdbus);

hw/sd/sd.c

@@ -126,8 +126,20 @@ struct SDState {
     BlockBackend *blk;
 
     bool enable;
+    uint8_t dat_lines;
+    bool cmd_line;
 };
 
+static uint8_t sd_get_dat_lines(SDState *sd)
+{
+    return sd->enable ? sd->dat_lines : 0;
+}
+
+static bool sd_get_cmd_line(SDState *sd)
+{
+    return sd->enable ? sd->cmd_line : false;
+}
+
 static void sd_set_voltage(SDState *sd, uint16_t millivolts)
 {
     switch (millivolts) {
@@ -457,6 +469,8 @@ static void sd_reset(DeviceState *dev)
     sd->blk_len = 0x200;
     sd->pwd_len = 0;
     sd->expecting_acmd = false;
+    sd->dat_lines = 0xf;
+    sd->cmd_line = true;
     sd->multi_blk_cnt = 0;
 }
 
@@ -1939,6 +1953,8 @@ static void sd_class_init(ObjectClass *klass, void *data)
     dc->bus_type = TYPE_SD_BUS;
 
     sc->set_voltage = sd_set_voltage;
+    sc->get_dat_lines = sd_get_dat_lines;
+    sc->get_cmd_line = sd_get_cmd_line;
     sc->do_command = sd_do_command;
     sc->write_data = sd_write_data;
     sc->read_data = sd_read_data;

hw/sd/sdhci-internal.h

@@ -82,6 +82,8 @@
 #define SDHC_CARD_PRESENT              0x00010000
 #define SDHC_CARD_DETECT               0x00040000
 #define SDHC_WRITE_PROTECT             0x00080000
+FIELD(SDHC_PRNSTS, DAT_LVL,            20, 4);
+FIELD(SDHC_PRNSTS, CMD_LVL,            24, 1);
 #define TRANSFERRING_DATA(x)           \
     ((x) & (SDHC_DOING_READ | SDHC_DOING_WRITE))
 

hw/sd/sdhci.c

@@ -1003,6 +1003,10 @@ static uint64_t sdhci_read(void *opaque, hwaddr offset, unsigned size)
         break;
     case SDHC_PRNSTS:
         ret = s->prnsts;
+        ret = FIELD_DP32(ret, SDHC_PRNSTS, DAT_LVL,
+                         sdbus_get_dat_lines(&s->sdbus));
+        ret = FIELD_DP32(ret, SDHC_PRNSTS, CMD_LVL,
+                         sdbus_get_cmd_line(&s->sdbus));
         break;
     case SDHC_HOSTCTL:
         ret = s->hostctl1 | (s->pwrcon << 8) | (s->blkgap << 16) |

hw/sd/trace-events

@@ -5,6 +5,8 @@ sdbus_command(const char *bus_name, uint8_t cmd, uint32_t arg, uint8_t crc) "@%s
 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)"
+sdbus_get_dat_lines(const char *bus_name, uint8_t dat_lines) "@%s dat_lines: %u"
+sdbus_get_cmd_line(const char *bus_name, bool cmd_line) "@%s cmd_line: %u"
 
 # hw/sd/sdhci.c
 sdhci_set_inserted(const char *level) "card state changed: %s"

include/hw/sd/sd.h

@@ -103,6 +103,8 @@ typedef struct {
     uint8_t (*read_data)(SDState *sd);
     bool (*data_ready)(SDState *sd);
     void (*set_voltage)(SDState *sd, uint16_t millivolts);
+    uint8_t (*get_dat_lines)(SDState *sd);
+    bool (*get_cmd_line)(SDState *sd);
     void (*enable)(SDState *sd, bool enable);
     bool (*get_inserted)(SDState *sd);
     bool (*get_readonly)(SDState *sd);
@@ -150,6 +152,8 @@ void sd_enable(SDState *sd, bool enable);
  * an SDBus rather than directly with SDState)
  */
 void sdbus_set_voltage(SDBus *sdbus, uint16_t millivolts);
+uint8_t sdbus_get_dat_lines(SDBus *sdbus);
+bool sdbus_get_cmd_line(SDBus *sdbus);
 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);