ENGR00295564 mmc: sdhci-esdhc-imx: no need busfreq for imx6qdl

The usdhc of i.MX6Q/DL can work well under low power mode without
request high bus freq. So we do not need request bus freq for i.MX6Q/DL.
It can save power for i.MX6D/DL due to it saves a lot busfreq switch
cost as well as the CPU time runing on high bus freq after switch
during low power mode.

A new flag ESDHC_FLAG_BUSFREQ is added to indicated this requirement.
Currently only i.MX6SL is using it.

Signed-off-by: Dong Aisheng <b29396@freescale.com>
(cherry picked from commit 075196777d00bf9507d68a76bf25f6c7e776102f)

diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index 3994b6a2b179533f173f1b2860219e9ae9c82148..d2eb8911dc9816fcfd3c4f9d989eaa5efaf7ba3c 100644 (file)
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -117,6 +117,8 @@
 #define ESDHC_FLAG_HAVE_CAP1           BIT(6)
 /* The IP has errata ERR004536 */
 #define ESDHC_FLAG_ERR004536           BIT(7)
+/* need request bus freq during low power */
+#define ESDHC_FLAG_BUSFREQ             BIT(8)
 
 struct esdhc_soc_data {
        u32 flags;
@@ -144,7 +146,8 @@ static struct esdhc_soc_data usdhc_imx6q_data = {
 
 static struct esdhc_soc_data usdhc_imx6sl_data = {
        .flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_STD_TUNING
-                       | ESDHC_FLAG_HAVE_CAP1 | ESDHC_FLAG_ERR004536,
+                       | ESDHC_FLAG_HAVE_CAP1 | ESDHC_FLAG_ERR004536
+                       | ESDHC_FLAG_BUSFREQ,
 };
 
 struct pltfm_imx_data {
@@ -1036,7 +1039,8 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
 
        pltfm_host->clk = imx_data->clk_per;
 
-       request_bus_freq(BUS_FREQ_HIGH);
+       if (imx_data->socdata->flags & ESDHC_FLAG_BUSFREQ)
+               request_bus_freq(BUS_FREQ_HIGH);
 
        clk_prepare_enable(imx_data->clk_per);
        clk_prepare_enable(imx_data->clk_ipg);
@@ -1190,7 +1194,8 @@ disable_clk:
        clk_disable_unprepare(imx_data->clk_per);
        clk_disable_unprepare(imx_data->clk_ipg);
        clk_disable_unprepare(imx_data->clk_ahb);
-       release_bus_freq(BUS_FREQ_HIGH);
+       if (imx_data->socdata->flags & ESDHC_FLAG_BUSFREQ)
+               release_bus_freq(BUS_FREQ_HIGH);
 free_sdhci:
        sdhci_pltfm_free(pdev);
        return err;
@@ -1225,7 +1230,8 @@ static int sdhci_esdhc_runtime_suspend(struct device *dev)
        clk_disable_unprepare(imx_data->clk_ipg);
        clk_disable_unprepare(imx_data->clk_ahb);
 
-       release_bus_freq(BUS_FREQ_HIGH);
+       if (imx_data->socdata->flags & ESDHC_FLAG_BUSFREQ)
+               release_bus_freq(BUS_FREQ_HIGH);
 
        return ret;
 }
@@ -1236,7 +1242,8 @@ static int sdhci_esdhc_runtime_resume(struct device *dev)
        struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
        struct pltfm_imx_data *imx_data = pltfm_host->priv;
 
-       request_bus_freq(BUS_FREQ_HIGH);
+       if (imx_data->socdata->flags & ESDHC_FLAG_BUSFREQ)
+               request_bus_freq(BUS_FREQ_HIGH);
 
        clk_prepare_enable(imx_data->clk_per);
        clk_prepare_enable(imx_data->clk_ipg);