Hi Adrian, > -----Original Message----- > From: Yangbo Lu [mailto:yangbo.lu@xxxxxxx] > Sent: Tuesday, April 11, 2017 1:10 PM > To: linux-mmc@xxxxxxxxxxxxxxx; ulf.hansson@xxxxxxxxxx; Adrian Hunter > Cc: Xiaobo Xie; Y.B. Lu > Subject: [v4, 1/5] mmc: sdhci-of-esdhc: add peripheral clock support > > eSDHC could select peripheral clock or platform clock as clock source by > the PCS bit of eSDHC Control Register, and this bit couldn't be reset by > software reset for all. In default, the platform clock is used. But we > have to use peripheral clock since it has a higher frequency to support > eMMC > HS200 mode and SD UHS-I mode. This patch is to add peripheral clock > support and use it instead of platform clock if it's declared in eSDHC > dts node. > > Signed-off-by: Yangbo Lu <yangbo.lu@xxxxxxx> > --- > Changes for v2: > - None > Changes for v3: > - None > Changes for v4: > - Added clk_put() > - Used udelay() to poll ESDHC_CLOCK_STABLE [Lu Yangbo-B47093] Could these changes address your comments? :) If yes, I think we can ask Uffe's help to merge these patches. Thanks a lot. - Yangbo Lu > --- > drivers/mmc/host/sdhci-esdhc.h | 1 + > drivers/mmc/host/sdhci-of-esdhc.c | 72 > +++++++++++++++++++++++++++++++++++++-- > 2 files changed, 71 insertions(+), 2 deletions(-) > > diff --git a/drivers/mmc/host/sdhci-esdhc.h b/drivers/mmc/host/sdhci- > esdhc.h index ece8b37..5343fc0 100644 > --- a/drivers/mmc/host/sdhci-esdhc.h > +++ b/drivers/mmc/host/sdhci-esdhc.h > @@ -54,6 +54,7 @@ > > /* Control Register for DMA transfer */ > #define ESDHC_DMA_SYSCTL 0x40c > +#define ESDHC_PERIPHERAL_CLK_SEL 0x00080000 > #define ESDHC_DMA_SNOOP 0x00000040 > > #endif /* _DRIVERS_MMC_SDHCI_ESDHC_H */ diff --git > a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c > index ff37e74..6d024b6 100644 > --- a/drivers/mmc/host/sdhci-of-esdhc.c > +++ b/drivers/mmc/host/sdhci-of-esdhc.c > @@ -19,6 +19,7 @@ > #include <linux/delay.h> > #include <linux/module.h> > #include <linux/sys_soc.h> > +#include <linux/clk.h> > #include <linux/mmc/host.h> > #include "sdhci-pltfm.h" > #include "sdhci-esdhc.h" > @@ -30,6 +31,7 @@ struct sdhci_esdhc { > u8 vendor_ver; > u8 spec_ver; > bool quirk_incorrect_hostver; > + unsigned int peripheral_clock; > }; > > /** > @@ -414,15 +416,25 @@ static int esdhc_of_enable_dma(struct sdhci_host > *host) static unsigned int esdhc_of_get_max_clock(struct sdhci_host > *host) { > struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); > + struct sdhci_esdhc *esdhc = sdhci_pltfm_priv(pltfm_host); > > - return pltfm_host->clock; > + if (esdhc->peripheral_clock) > + return esdhc->peripheral_clock; > + else > + return pltfm_host->clock; > } > > static unsigned int esdhc_of_get_min_clock(struct sdhci_host *host) { > struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); > + struct sdhci_esdhc *esdhc = sdhci_pltfm_priv(pltfm_host); > + unsigned int clock; > > - return pltfm_host->clock / 256 / 16; > + if (esdhc->peripheral_clock) > + clock = esdhc->peripheral_clock; > + else > + clock = pltfm_host->clock; > + return clock / 256 / 16; > } > > static void esdhc_of_set_clock(struct sdhci_host *host, unsigned int > clock) @@ -512,6 +524,33 @@ static void esdhc_pltfm_set_bus_width(struct > sdhci_host *host, int width) > sdhci_writel(host, ctrl, ESDHC_PROCTL); } > > +static void esdhc_clock_enable(struct sdhci_host *host, bool enable) { > + u32 val; > + ktime_t timeout; > + > + val = sdhci_readl(host, ESDHC_SYSTEM_CONTROL); > + > + if (enable) > + val |= ESDHC_CLOCK_SDCLKEN; > + else > + val &= ~ESDHC_CLOCK_SDCLKEN; > + > + sdhci_writel(host, val, ESDHC_SYSTEM_CONTROL); > + > + /* Wait max 20 ms */ > + timeout = ktime_add_ms(ktime_get(), 20); > + val = ESDHC_CLOCK_STABLE; > + while (!(sdhci_readl(host, ESDHC_PRSSTAT) & val)) { > + if (ktime_after(ktime_get(), timeout)) { > + pr_err("%s: Internal clock never stabilised.\n", > + mmc_hostname(host->mmc)); > + break; > + } > + udelay(10); > + } > +} > + > static void esdhc_reset(struct sdhci_host *host, u8 mask) { > sdhci_reset(host, mask); > @@ -613,6 +652,9 @@ static void esdhc_init(struct platform_device *pdev, > struct sdhci_host *host) { > struct sdhci_pltfm_host *pltfm_host; > struct sdhci_esdhc *esdhc; > + struct device_node *np; > + struct clk *clk; > + u32 val; > u16 host_ver; > > pltfm_host = sdhci_priv(host); > @@ -626,6 +668,32 @@ static void esdhc_init(struct platform_device *pdev, > struct sdhci_host *host) > esdhc->quirk_incorrect_hostver = true; > else > esdhc->quirk_incorrect_hostver = false; > + > + np = pdev->dev.of_node; > + clk = of_clk_get(np, 0); > + if (!IS_ERR(clk)) { > + /* > + * esdhc->peripheral_clock would be assigned with a value > + * which is eSDHC base clock when use periperal clock. > + * For ls1046a, the clock value got by common clk API is > + * peripheral clock while the eSDHC base clock is 1/2 > + * peripheral clock. > + */ > + if (of_device_is_compatible(np, "fsl,ls1046a-esdhc")) > + esdhc->peripheral_clock = clk_get_rate(clk) / 2; > + else > + esdhc->peripheral_clock = clk_get_rate(clk); > + > + clk_put(clk); > + } > + > + if (esdhc->peripheral_clock) { > + esdhc_clock_enable(host, false); > + val = sdhci_readl(host, ESDHC_DMA_SYSCTL); > + val |= ESDHC_PERIPHERAL_CLK_SEL; > + sdhci_writel(host, val, ESDHC_DMA_SYSCTL); > + esdhc_clock_enable(host, true); > + } > } > > static int sdhci_esdhc_probe(struct platform_device *pdev) > -- > 2.1.0.27.g96db324 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
