[PATCH] sdhci: allow for eMMC 74 clock generation by controller

[Philip Rakity]

Wolfram,

I generated the patch for eMMC 74 clocks.  I do not know if you want to 
incorporate into your submission or let it stand on its own.

regards,

Philip



From: Philip Rakity <prak...@marvell.com>
Subject: [PATCH] sdhci: allow for eMMC 74 clock generation by controller
Signed-off-by: Philip Rakity <prak...@marvell.com>

Patch is below and sample usage in sdhci-xxxx.c adaption code is below.

/*
 * eMMC spec calls for the host to send 74 clocks to the card
 * during initialization, right after voltage stabilization.
 * create the clocks manually right here.
 */
void generate_init_clocks_A0(struct sdhci_host *host, u8 power_mode)
{
        struct sdhci_mmc_slot *slot = sdhci_priv(host);

        DBG ("%s: ENTER %s: slot->power_mode = %d, ios->power_mode = %d\n",
                __func__, 
                mmc_hostname(host->mmc),
                slot->power_mode, 
                power_mode);

        if (slot->power_mode == MMC_POWER_UP 
        && power_mode == MMC_POWER_ON) {
        
                /* controller specific code here */
                /* slot->power_mode holds previous power setting */

        }
        slot->power_mode = power_mode;
}



diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 401527d..6aadd0f 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1168,6 +1168,9 @@ static void sdhci_set_ios(struct mmc_host *mmc, struct 
mmc_ios *ios)
        else
                sdhci_set_power(host, ios->vdd);
 
+       if (host->ops->platform_generate_initial_74_clocks)
+               host->ops->platform_generate_initial_74_clocks(host, 
ios->power_mode);
+
        ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
 
        if (ios->bus_width == MMC_BUS_WIDTH_8)
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index d316bc7..70c5806 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -323,6 +323,8 @@ struct sdhci_ops {
        unsigned int    (*get_max_clock)(struct sdhci_host *host);
        unsigned int    (*get_min_clock)(struct sdhci_host *host);
        unsigned int    (*get_timeout_clock)(struct sdhci_host *host);
+       void            (*platform_generate_initial_74_clocks)(struct 
sdhci_host *host,
+                               u8 power_mode);
 };
 
 #ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS

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