| Message ID | 1456972613-8159-1-git-send-email-shawn.lin@rock-chips.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 3.3.2016 03:36, Shawn Lin wrote: > Currently sdhci-arasan 5.1 can support enhanced strobe function, > but considering the potential requirement in the future for other > version IP, we don't limit it just for "arasan,sdhci-5.1". Add > cap-enhanced-strobe in DT to enable the function if we'r sure our > controller can support it. > > Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> > --- > > drivers/mmc/host/sdhci-of-arasan.c | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) > > diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c > index 1e4b5e0..31f3494 100644 > --- a/drivers/mmc/host/sdhci-of-arasan.c > +++ b/drivers/mmc/host/sdhci-of-arasan.c > @@ -24,7 +24,9 @@ > #include "sdhci-pltfm.h" > > #define SDHCI_ARASAN_CLK_CTRL_OFFSET 0x2c > +#define SDHCI_ARASAN_VENDOR_REGISTER 0x78 I was checking our register map and we even don't have this register listed as reserved. It looks like that this will be related to certain SoC and different SoC can use it different location. That's why I think this feature and setup should be related to certain SoC specific compatible string. Thanks, Michal -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2016/3/3 19:02, Michal Simek wrote: > On 3.3.2016 03:36, Shawn Lin wrote: >> Currently sdhci-arasan 5.1 can support enhanced strobe function, >> but considering the potential requirement in the future for other >> version IP, we don't limit it just for "arasan,sdhci-5.1". Add >> cap-enhanced-strobe in DT to enable the function if we'r sure our >> controller can support it. >> >> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> >> --- >> >> drivers/mmc/host/sdhci-of-arasan.c | 20 ++++++++++++++++++++ >> 1 file changed, 20 insertions(+) >> >> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c >> index 1e4b5e0..31f3494 100644 >> --- a/drivers/mmc/host/sdhci-of-arasan.c >> +++ b/drivers/mmc/host/sdhci-of-arasan.c >> @@ -24,7 +24,9 @@ >> #include "sdhci-pltfm.h" >> >> #define SDHCI_ARASAN_CLK_CTRL_OFFSET 0x2c >> +#define SDHCI_ARASAN_VENDOR_REGISTER 0x78 > > I was checking our register map and we even don't have this register > listed as reserved. > It looks like that this will be related to certain SoC and different SoC > can use it different location. > That's why I think this feature and setup should be related to certain > SoC specific compatible string. Hi Michal, I think that is IP version specific because it's inside controller's databook. But I only have a datasheet released by arasan for 5.1 controller, so I didn't know if your databook has this register. And I can't find sdhci spec has a reg to enable this feature either. Looks strange, but maybe you are right: it also related to certain Soc for other sdhci variant drivers. But for sdhci-of-arsan, it more likes to use this register from now on for the future IP version to enable this feature inside the controller register-range. Thanks for checking that. Now, I'm more sure about that we should limit it for 5.1 currently by checking the compatible string. I expect more comments from ulf and adrian about the other part of code until I respin the next version. > > Thanks, > Michal > > > >
diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c index 1e4b5e0..31f3494 100644 --- a/drivers/mmc/host/sdhci-of-arasan.c +++ b/drivers/mmc/host/sdhci-of-arasan.c @@ -24,7 +24,9 @@ #include "sdhci-pltfm.h" #define SDHCI_ARASAN_CLK_CTRL_OFFSET 0x2c +#define SDHCI_ARASAN_VENDOR_REGISTER 0x78 +#define VENDOR_ENHANCED_STROBE BIT(0) #define CLK_CTRL_TIMEOUT_SHIFT 16 #define CLK_CTRL_TIMEOUT_MASK (0xf << CLK_CTRL_TIMEOUT_SHIFT) #define CLK_CTRL_TIMEOUT_MIN_EXP 13 @@ -52,6 +54,21 @@ static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host) return freq; } +static int sdhci_arasan_enhanced_strobe(struct sdhci_host *host, bool enable) +{ + u32 vendor; + + vendor = readl(host->ioaddr + SDHCI_ARASAN_VENDOR_REGISTER); + if (enable) + vendor |= VENDOR_ENHANCED_STROBE; + else + vendor &= (~VENDOR_ENHANCED_STROBE); + + writel(vendor, host->ioaddr + SDHCI_ARASAN_VENDOR_REGISTER); + + return 0; +} + static struct sdhci_ops sdhci_arasan_ops = { .set_clock = sdhci_set_clock, .get_max_clock = sdhci_pltfm_clk_get_max_clock, @@ -172,6 +189,9 @@ static int sdhci_arasan_probe(struct platform_device *pdev) sdhci_get_of_property(pdev); pltfm_host->clk = clk_xin; + host->mmc_host_ops.prepare_enhanced_strobe = + sdhci_arasan_enhanced_strobe; + ret = mmc_of_parse(host->mmc); if (ret) { dev_err(&pdev->dev, "parsing dt failed (%u)\n", ret);
Currently sdhci-arasan 5.1 can support enhanced strobe function, but considering the potential requirement in the future for other version IP, we don't limit it just for "arasan,sdhci-5.1". Add cap-enhanced-strobe in DT to enable the function if we'r sure our controller can support it. Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> --- drivers/mmc/host/sdhci-of-arasan.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)