It blinks to caution the user not to remove the card while the SD card is
being accessed.
So far it only emits a trace event.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Acked-by: Alistair Francis <alistair.francis@xilinx.com>
---
 include/hw/sd/sdhci.h |  2 ++
 hw/sd/sdhci.c         | 14 ++++++++++++++
 hw/sd/trace-events    |  1 +
 3 files changed, 17 insertions(+)

diff --git a/include/hw/sd/sdhci.h b/include/hw/sd/sdhci.h
index a6fe064f51..da943a6562 100644
--- a/include/hw/sd/sdhci.h
+++ b/include/hw/sd/sdhci.h
@@ -45,6 +45,8 @@ typedef struct SDHCIState {
     QEMUTimer *insert_timer;       /* timer for 'changing' sd card. */
     QEMUTimer *transfer_timer;
     qemu_irq irq;
+    qemu_irq access_led;
+    int access_led_level;
 
     /* Registers cleared on reset */
     /* 0x00 */
diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c
index 26a98d999a..3f550bc7df 100644
--- a/hw/sd/sdhci.c
+++ b/hw/sd/sdhci.c
@@ -204,6 +204,16 @@ static void sdhci_poweron_reset(DeviceState *dev)
     }
 }
 
+static void sdhci_led_handler(void *opaque, int line, int level)
+{
+    SDHCIState *s = (SDHCIState *)opaque;
+
+    if (s->access_led_level != level) {
+        trace_sdhci_led(level);
+        s->access_led_level = level;
+    }
+}
+
 static void sdhci_data_transfer(void *opaque);
 
 static void sdhci_send_command(SDHCIState *s)
@@ -1052,6 +1062,7 @@ sdhci_write(void *opaque, hwaddr offset, uint64_t val, unsigned size)
                 !(s->capareg & (1 << (31 - ((s->pwrcon >> 1) & 0x7))))) {
             s->pwrcon &= ~SDHC_POWER_ON;
         }
+        qemu_set_irq(s->access_led, s->hostctl & 1);
         break;
     case SDHC_CLKCON:
         if (!(mask & 0xFF000000)) {
@@ -1164,6 +1175,7 @@ static void sdhci_initfn(SDHCIState *s)
     qbus_create_inplace(&s->sdbus, sizeof(s->sdbus),
                         TYPE_SDHCI_BUS, DEVICE(s), "sd-bus");
 
+    s->access_led = qemu_allocate_irq(sdhci_led_handler, s, 0);
     s->insert_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, sdhci_raise_insertion_irq, s);
     s->transfer_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, sdhci_data_transfer, s);
 }
@@ -1194,6 +1206,8 @@ static void sdhci_uninitfn(SDHCIState *s)
     timer_free(s->insert_timer);
     timer_del(s->transfer_timer);
     timer_free(s->transfer_timer);
+
+    qemu_free_irq(s->access_led);
 }
 
 static bool sdhci_pending_insert_vmstate_needed(void *opaque)
diff --git a/hw/sd/trace-events b/hw/sd/trace-events
index e4e26c6d73..f821db2046 100644
--- a/hw/sd/trace-events
+++ b/hw/sd/trace-events
@@ -13,6 +13,7 @@ sdhci_adma_transfer_completed(void) "ADMA transfer completed"
 sdhci_access(const char *access, unsigned int size, uint64_t offset, const char *dir, uint64_t val, uint64_t val2) "%s %ub: addr[0x%04" PRIx64 "] %s %" PRIu64 "(0x%" PRIx64 ")"
 sdhci_read_dataport(uint16_t data_count) "all %u bytes of data have been read from input buffer"
 sdhci_write_dataport(uint16_t data_count) "write buffer filled with %u bytes of data"
+sdhci_led(bool state) "LED: %u"
 
 # hw/sd/milkymist-memcard.c
 milkymist_memcard_memory_read(uint32_t addr, uint32_t value) "addr 0x%08x value 0x%08x"
-- 
2.15.1