mmc: tmio: fix never-detected card insertion bug

The TMIO mmc cannot detect the card insertion in native_hotplug mode
if the driver is probed without a card inserted.

The reason is obvious; all IRQs are disabled by tmio_mmc_host_probe(),
as follows:

  tmio_mmc_disable_mmc_irqs(_host, TMIO_MASK_ALL);

The card event IRQs are first enabled by tmio_mmc_start_command() as
follows:

  if (!host->native_hotplug)
          irq_mask &= ~(TMIO_STAT_CARD_REMOVE | TMIO_STAT_CARD_INSERT);
  tmio_mmc_enable_mmc_irqs(host, irq_mask);

If the driver is probed without a card, tmio_mmc_start_command() is
never called in the first place.  So, the card is never detected.

The card event IRQs must be enabled in probe/resume functions.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

drivers/mmc/host/tmio_mmc_core.c

@@ -350,8 +350,6 @@ static int tmio_mmc_start_command(struct tmio_mmc_host *host,
 			c |= TRANSFER_READ;
 	}
 
-	if (!host->native_hotplug)
-		irq_mask &= ~(TMIO_STAT_CARD_REMOVE | TMIO_STAT_CARD_INSERT);
 	tmio_mmc_enable_mmc_irqs(host, irq_mask);
 
 	/* Fire off the command */
@@ -1280,11 +1278,13 @@ int tmio_mmc_host_probe(struct tmio_mmc_host *_host)
 		irq_mask |= TMIO_MASK_READOP;
 	if (!_host->chan_tx)
 		irq_mask |= TMIO_MASK_WRITEOP;
-	if (!_host->native_hotplug)
-		irq_mask &= ~(TMIO_STAT_CARD_REMOVE | TMIO_STAT_CARD_INSERT);
 
 	_host->sdcard_irq_mask &= ~irq_mask;
 
+	if (_host->native_hotplug)
+		tmio_mmc_enable_mmc_irqs(_host,
+				TMIO_STAT_CARD_REMOVE | TMIO_STAT_CARD_INSERT);
+
 	spin_lock_init(&_host->lock);
 	mutex_init(&_host->ios_lock);
 
@@ -1382,6 +1382,10 @@ int tmio_mmc_host_runtime_resume(struct device *dev)
 	if (host->clk_cache)
 		tmio_mmc_set_clock(host, host->clk_cache);
 
+	if (host->native_hotplug)
+		tmio_mmc_enable_mmc_irqs(host,
+				TMIO_STAT_CARD_REMOVE | TMIO_STAT_CARD_INSERT);
+
 	tmio_mmc_enable_dma(host, true);
 
 	if (tmio_mmc_can_retune(host) && host->select_tuning(host))