mmc: tmio: runtime suspend the controller, where possible

The TMIO MMC controller cannot be powered off to save power, when no
card is plugged in, because then it will not be able to detect a new
card-insertion event. On some implementations, however, it is
possible to switch to using another source to detect card insertion.
This patch adds support for such implementations.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>

1 files changed, 17 insertions, 0 deletions

diff --git a/include/linux/mfd/tmio.h b/include/linux/mfd/tmio.h
index 8e70310ee945..5a90266c3a5a 100644
--- a/include/linux/mfd/tmio.h
+++ b/include/linux/mfd/tmio.h
@@ -4,6 +4,7 @@
 #include <linux/fb.h>
 #include <linux/io.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 
 #define tmio_ioread8(addr) readb(addr)
 #define tmio_ioread16(addr) readw(addr)
@@ -61,6 +62,12 @@
  * Some controllers can support SDIO IRQ signalling.
  */
 #define TMIO_MMC_SDIO_IRQ               (1 << 2)
+/*
+ * Some platforms can detect card insertion events with controller powered
+ * down, in which case they have to call tmio_mmc_cd_wakeup() to power up the
+ * controller and report the event to the driver.
+ */
+#define TMIO_MMC_HAS_COLD_CD            (1 << 3)
 
 int tmio_core_mmc_enable(void __iomem *cnf, int shift, unsigned long base);
 int tmio_core_mmc_resume(void __iomem *cnf, int shift, unsigned long base);
@@ -82,11 +89,21 @@ struct tmio_mmc_data {
         unsigned long                   flags;
         u32                             ocr_mask;       /* available voltages */
         struct tmio_mmc_dma             *dma;
+        struct device                   *dev;
+        bool                            power;
         void (*set_pwr)(struct platform_device *host, int state);
         void (*set_clk_div)(struct platform_device *host, int state);
         int (*get_cd)(struct platform_device *host);
 };
 
+static inline void tmio_mmc_cd_wakeup(struct tmio_mmc_data *pdata)
+{
+        if (pdata && !pdata->power) {
+                pdata->power = true;
+                pm_runtime_get(pdata->dev);
+        }
+}
+
 /*
  * data for the NAND controller
  */