Instead of reading a register value everytime we need to apply a new value for it, maintain a cached copy for it. This also means we are able to skip writes that are not needed.
Tested-by: Linus Walleij <[email protected]> Signed-off-by: Ulf Hansson <[email protected]> Signed-off-by: Linus Walleij <[email protected]> --- drivers/mmc/host/mmci.c | 41 +++++++++++++++++++++++++++++------------ drivers/mmc/host/mmci.h | 3 ++- 2 files changed, 31 insertions(+), 13 deletions(-) diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c index 9e544cf..0de2f3d 100644 --- a/drivers/mmc/host/mmci.c +++ b/drivers/mmc/host/mmci.c @@ -121,6 +121,28 @@ static struct variant_data variant_ux500v2 = { /* * This must be called with host->lock held */ +static void mmci_write_clkreg(struct mmci_host *host, u32 clk) +{ + if (host->clk_reg != clk) { + host->clk_reg = clk; + writel(clk, host->base + MMCICLOCK); + } +} + +/* + * This must be called with host->lock held + */ +static void mmci_write_pwrreg(struct mmci_host *host, u32 pwr) +{ + if (host->pwr_reg != pwr) { + host->pwr_reg = pwr; + writel(pwr, host->base + MMCIPOWER); + } +} + +/* + * This must be called with host->lock held + */ static void mmci_set_clkreg(struct mmci_host *host, unsigned int desired) { struct variant_data *variant = host->variant; @@ -165,7 +187,7 @@ static void mmci_set_clkreg(struct mmci_host *host, unsigned int desired) if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_8) clk |= MCI_ST_8BIT_BUS; - writel(clk, host->base + MMCICLOCK); + mmci_write_clkreg(host, clk); } static void @@ -843,14 +865,13 @@ static int mmci_pio_write(struct mmci_host *host, char *buffer, unsigned int rem */ if (variant->sdio && mmc_card_sdio(host->mmc->card)) { + u32 clk; if (count < 8) - writel(readl(host->base + MMCICLOCK) & - ~variant->clkreg_enable, - host->base + MMCICLOCK); + clk = host->clk_reg & ~variant->clkreg_enable; else - writel(readl(host->base + MMCICLOCK) | - variant->clkreg_enable, - host->base + MMCICLOCK); + clk = host->clk_reg | variant->clkreg_enable; + + mmci_write_clkreg(host, clk); } /* @@ -1111,11 +1132,7 @@ static void mmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) spin_lock_irqsave(&host->lock, flags); mmci_set_clkreg(host, ios->clock); - - if (host->pwr != pwr) { - host->pwr = pwr; - writel(pwr, host->base + MMCIPOWER); - } + mmci_write_pwrreg(host, pwr); spin_unlock_irqrestore(&host->lock, flags); diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h index 89eb2e3..d437ccf 100644 --- a/drivers/mmc/host/mmci.h +++ b/drivers/mmc/host/mmci.h @@ -179,7 +179,8 @@ struct mmci_host { unsigned int mclk; unsigned int cclk; - u32 pwr; + u32 pwr_reg; + u32 clk_reg; struct mmci_platform_data *plat; struct variant_data *variant; -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
