[PATCH 1/3] MMCI Break out clock divider setup

[linux@arm.linux.org.uk (Russell King - ARM Linux)]

Unfortunately, these patches can not be applied in their current form
because they don't take account of the conflicting changes already in
my tree.

On Wed, Sep 09, 2009 at 10:55:00PM +0200, Linus Walleij wrote:
> This breaks out the clock divider set-up code from the
> mmci_set_ios() code and surrounds the two register
> writes with a host lock so we don't get collisions if
> (in future code) two code paths want to change the
> clock divider at the same time as can be the case if
> we get something like pre/post- clock frequency change
> notifications soonish.
> 
> Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
> ---
>  drivers/mmc/host/mmci.c |   49 +++++++++++++++++++++++++++++++---------------
>  1 files changed, 33 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
> index a923ee2..083f9b8 100644
> --- a/drivers/mmc/host/mmci.c
> +++ b/drivers/mmc/host/mmci.c
> @@ -38,6 +38,33 @@
>  
>  static unsigned int fmax = 515633;
>  
> +/*
> + * This must be called with host->lock held
> + */
> +static void mmci_set_clkreg(struct mmci_host *host, unsigned int desired)
> +{
> +	u32 clk = 0;
> +
> +	if (desired) {
> +		if (desired >= host->mclk) {
> +			clk = MCI_CLK_BYPASS;
> +			host->cclk = host->mclk;
> +		} else {
> +			clk = host->mclk / (2 * desired) - 1;
> +			if (clk >= 256)
> +				clk = 255;
> +			host->cclk = host->mclk / (2 * (clk + 1));
> +		}
> +		if (host->hw_designer == 0x80)
> +			clk |= MCI_FCEN; /* Bug fix in ST IP block */
> +		clk |= MCI_CLK_ENABLE;
> +		/* This hasn't proven to be worthwhile */
> +		/* clk |= MCI_CLK_PWRSAVE; */
> +	}
> +
> +	writel(clk, host->base + MMCICLOCK);
> +}
> +
>  static void
>  mmci_request_end(struct mmci_host *host, struct mmc_request *mrq)
>  {
> @@ -420,21 +447,7 @@ static void mmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>  {
>  	struct mmci_host *host = mmc_priv(mmc);
>  	u32 clk = 0, pwr = 0;
> -
> -	if (ios->clock) {
> -		if (ios->clock >= host->mclk) {
> -			clk = MCI_CLK_BYPASS;
> -			host->cclk = host->mclk;
> -		} else {
> -			clk = host->mclk / (2 * ios->clock) - 1;
> -			if (clk >= 256)
> -				clk = 255;
> -			host->cclk = host->mclk / (2 * (clk + 1));
> -		}
> -		if (host->hw_designer == 0x80)
> -			clk |= MCI_FCEN; /* Bug fix in ST IP block */
> -		clk |= MCI_CLK_ENABLE;
> -	}
> +	unsigned long flags;
>  
>  	if (host->plat->translate_vdd)
>  		pwr |= host->plat->translate_vdd(mmc_dev(mmc), ios->vdd);
> @@ -465,12 +478,16 @@ static void mmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>  		}
>  	}
>  
> -	writel(clk, host->base + MMCICLOCK);
> +	spin_lock_irqsave(&host->lock, flags);
> +
> +	mmci_set_clkreg(host, ios->clock);
>  
>  	if (host->pwr != pwr) {
>  		host->pwr = pwr;
>  		writel(pwr, host->base + MMCIPOWER);
>  	}
> +
> +	spin_unlock_irqrestore(&host->lock, flags);
>  }
>  
>  static int mmci_get_ro(struct mmc_host *mmc)
> -- 
> 1.6.2.1
> 
> 
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