mmc: tmio: fix unbalanced power-on calls with clock-gating enabled
With MMC clock gating enabled the MMC core currently calls MMC host driver's
.set_ios() method with .power_mode == MMC_POWER_ON and the clock value set
either to 0 or to the target rate. The tmio MMC driver then wrongly
translates the latter calls to card slot power-on requests, even when the
slot already was on. This patch fixes the driver to avoid needlessly
incrementing power-supplying regulator's use count.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h
index 759d8f4..86fd21e 100644
--- a/drivers/mmc/host/tmio_mmc.h
+++ b/drivers/mmc/host/tmio_mmc.h
@@ -40,6 +40,22 @@
struct tmio_mmc_data;
+/*
+ * We differentiate between the following 3 power states:
+ * 1. card slot powered off, controller stopped. This is used, when either there
+ * is no card in the slot, or the card really has to be powered down.
+ * 2. card slot powered on, controller stopped. This is used, when a card is in
+ * the slot, but no activity is currently taking place. This is a power-
+ * saving mode with card-state preserved. This state can be entered, e.g.
+ * when MMC clock-gating is used.
+ * 3. card slot powered on, controller running. This is the actual active state.
+ */
+enum tmio_mmc_power {
+ TMIO_MMC_OFF_STOP, /* card power off, controller stopped */
+ TMIO_MMC_ON_STOP, /* card power on, controller stopped */
+ TMIO_MMC_ON_RUN, /* card power on, controller running */
+};
+
struct tmio_mmc_host {
void __iomem *ctl;
unsigned long bus_shift;
@@ -48,8 +64,8 @@
struct mmc_data *data;
struct mmc_host *mmc;
- /* Controller power state */
- bool power;
+ /* Controller and card power state */
+ enum tmio_mmc_power power;
/* Callbacks for clock / power control */
void (*set_pwr)(struct platform_device *host, int state);