mmc: core: Ensure clocks are always enabled before host interaction

Ensure clocks are always enabled before any interaction with the
host controller driver. This makes sure that there is no race
between host execution and the core layer turning off clocks
in different context with clock gating framework.

Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Per Forlin <per.forlin@stericsson.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

1 files changed, 19 insertions, 0 deletions

diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 0beba1e5e1ed..73e5ee8e9ca2 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -444,4 +444,23 @@ static inline int mmc_boot_partition_access(struct mmc_host *host)
         return !(host->caps2 & MMC_CAP2_BOOTPART_NOACC);
 }
 
+#ifdef CONFIG_MMC_CLKGATE
+void mmc_host_clk_hold(struct mmc_host *host);
+void mmc_host_clk_release(struct mmc_host *host);
+unsigned int mmc_host_clk_rate(struct mmc_host *host);
+
+#else
+static inline void mmc_host_clk_hold(struct mmc_host *host)
+{
+}
+
+static inline void mmc_host_clk_release(struct mmc_host *host)
+{
+}
+
+static inline unsigned int mmc_host_clk_rate(struct mmc_host *host)
+{
+        return host->ios.clock;
+}
+#endif
 #endif /* LINUX_MMC_HOST_H */