This patch is different from the previous patch due to changes in the latest mmp2 silicon.
reverified under Marvell MMP2 linux on brownstone using SDIO/SD, MMC/Plus and eMMC. Clock gating verified using scope for external cards SD, MMC/Plus and SDIO. debug log used to verify eMMC >From f7b98789396dd59d4abf5f34e4ccca138944e294 Mon Sep 17 00:00:00 2001 From: Philip Rakity <[email protected]> Date: Wed, 8 Dec 2010 15:23:23 -0800 Subject: [PATCH] sdhci: add support for H/W clock gating of SD controller MMP2 controller allows clock gating for SD/eMMC/SDIO cards by extending the definition for SDCTRL_2_ASYNC_INT_EN in the host control register 2. The SD Host Controller spec defines this bit (14) for use with SDIO. Signed-off-by: Philip Rakity <[email protected]> Signed-off-by: Mark F. Brown <[email protected]> --- drivers/mmc/host/sdhci-pxa.c | 42 +++++++++++++++++++++++++++++++++--------- 1 files changed, 33 insertions(+), 9 deletions(-) diff --git a/drivers/mmc/host/sdhci-pxa.c b/drivers/mmc/host/sdhci-pxa.c index 5a61208..125cda8 100644 --- a/drivers/mmc/host/sdhci-pxa.c +++ b/drivers/mmc/host/sdhci-pxa.c @@ -25,13 +25,11 @@ #include <linux/io.h> #include <linux/err.h> #include <plat/sdhci.h> +#include <mach/cputype.h> #include "sdhci.h" #define DRIVER_NAME "sdhci-pxa" -#define SD_FIFO_PARAM 0x104 -#define DIS_PAD_SD_CLK_GATE 0x400 - struct sdhci_pxa { struct sdhci_host *host; struct sdhci_pxa_platdata *pdata; @@ -46,10 +44,33 @@ struct sdhci_pxa { * SDHCI core callbacks * * * \*****************************************************************************/ +#ifdef CONFIG_MMC_CLKGATE +static void hardware_clk_gating(struct sdhci_host *host) +{ + unsigned short tmp; + int enable; + + /* + * MMP2 controller allows clock gating for SD/eMMC/SDIO cards + * by extending the definition for SDCTRL_2_ASYNC_INT_EN in the + * host control register 2. The SD Host Controller spec + * defines this bit for use with SDIO. + */ + enable = host->mmc->clk_gated; + tmp = readw(host->ioaddr + HOST_CTRL_2); + + if (enable) + tmp |= SDCTRL_2_ASYNC_INT_EN; + else + tmp &= ~SDCTRL_2_ASYNC_INT_EN; + + writew(tmp, host->ioaddr + HOST_CTRL_2); +} +#endif + static void set_clock(struct sdhci_host *host, unsigned int clock) { struct sdhci_pxa *pxa = sdhci_priv(host); - u32 tmp = 0; if (clock == 0) { if (pxa->clk_enable) { @@ -58,11 +79,6 @@ static void set_clock(struct sdhci_host *host, unsigned int clock) } } else { if (0 == pxa->clk_enable) { - if (pxa->pdata->flags & PXA_FLAG_DISABLE_CLOCK_GATING) { - tmp = readl(host->ioaddr + SD_FIFO_PARAM); - tmp |= DIS_PAD_SD_CLK_GATE; - writel(tmp, host->ioaddr + SD_FIFO_PARAM); - } clk_enable(pxa->clk); pxa->clk_enable = 1; } @@ -71,6 +87,9 @@ static void set_clock(struct sdhci_host *host, unsigned int clock) static struct sdhci_ops sdhci_pxa_ops = { .set_clock = set_clock, +#ifdef CONFIG_MMC_CLKGATE + .platform_hw_clk_gate = hardware_clk_gating, +#endif }; /*****************************************************************************\ @@ -145,6 +164,11 @@ static int __devinit sdhci_pxa_probe(struct platform_device *pdev) if (pdata->flags & PXA_FLAG_SD_8_BIT_CAPABLE_SLOT) host->mmc->caps |= MMC_CAP_8_BIT_DATA; +#ifdef CONFIG_MMC_CLKGATE + if (cpu_is_mmp2()) + host->mmc->caps |= MMC_CAP_HW_CLOCK_GATING; +#endif + ret = sdhci_add_host(host); if (ret) { dev_err(&pdev->dev, "failed to add host\n"); -- 1.6.0.4 -- 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
