RE: [PATCH 3/3 v2] mmc: Add ESDHC weird voltage bits workaround
-Original Message- From: Anton Vorontsov [mailto:cbouatmai...@gmail.com] Sent: Friday, July 30, 2010 15:06 PM To: Zang Roy-R61911 Cc: linux-...@vger.kernel.org; linuxppc-...@ozlabs.org; a...@linux-foundation.org Subject: Re: [PATCH 3/3 v2] mmc: Add ESDHC weird voltage bits workaround On Fri, Jul 30, 2010 at 11:52:57AM +0800, Roy Zang wrote: P4080 ESDHC controller does not support 1.8V and 3.0V voltage. but the host controller capabilities register wrongly set the bits. This patch adds the workaround to correct the weird voltage setting bits. Signed-off-by: Roy Zang tie-fei.z...@freescale.com --- [...] diff --git a/drivers/mmc/host/sdhci-of-core.c b/drivers/mmc/host/sdhci-of-core.c index 0c30242..1f3913d 100644 --- a/drivers/mmc/host/sdhci-of-core.c +++ b/drivers/mmc/host/sdhci-of-core.c @@ -164,6 +164,10 @@ static int __devinit sdhci_of_probe(struct of_device *ofdev, if (sdhci_of_wp_inverted(np)) host-quirks |= SDHCI_QUIRK_INVERTED_WRITE_PROTECT; + if (of_device_is_compatible(np, fsl,p4080-esdhc)) + host-quirks |= (SDHCI_QUIRK_QORIQ_NO_VDD_180 + |SDHCI_QUIRK_QORIQ_NO_VDD_300); + It should be two properties, something like sdhci,no-vdd-180 and sdhci,no-vdd-300. But it might be even better: we have voltage-ranges for mmc-spi case, see Documentation/powerpc/dts-bindings/mmc-spi-slot.txt. If voltage-ranges specified, then we use it, not capabilities register. For p4080 it will be 'voltage-ranges = 3200 3400;'. So, with voltage-ranges we can do fine grained VDD control without introducing anything new. why not voltage-ranges = 3300 3300; ? Roy ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH 3/3 v2] mmc: Add ESDHC weird voltage bits workaround
On Mon, Aug 02, 2010 at 02:19:58PM +0800, Zang Roy-R61911 wrote: [...] For p4080 it will be 'voltage-ranges = 3200 3400;'. So, with voltage-ranges we can do fine grained VDD control without introducing anything new. why not voltage-ranges = 3300 3300; Right you are, both will be 3300. Thanks, -- Anton Vorontsov email: cbouatmai...@gmail.com irc://irc.freenode.net/bd2 ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH 3/3 v2] mmc: Add ESDHC weird voltage bits workaround
On Fri, Jul 30, 2010 at 11:52:57AM +0800, Roy Zang wrote: P4080 ESDHC controller does not support 1.8V and 3.0V voltage. but the host controller capabilities register wrongly set the bits. This patch adds the workaround to correct the weird voltage setting bits. Signed-off-by: Roy Zang tie-fei.z...@freescale.com --- [...] diff --git a/drivers/mmc/host/sdhci-of-core.c b/drivers/mmc/host/sdhci-of-core.c index 0c30242..1f3913d 100644 --- a/drivers/mmc/host/sdhci-of-core.c +++ b/drivers/mmc/host/sdhci-of-core.c @@ -164,6 +164,10 @@ static int __devinit sdhci_of_probe(struct of_device *ofdev, if (sdhci_of_wp_inverted(np)) host-quirks |= SDHCI_QUIRK_INVERTED_WRITE_PROTECT; + if (of_device_is_compatible(np, fsl,p4080-esdhc)) + host-quirks |= (SDHCI_QUIRK_QORIQ_NO_VDD_180 + |SDHCI_QUIRK_QORIQ_NO_VDD_300); + It should be two properties, something like sdhci,no-vdd-180 and sdhci,no-vdd-300. But it might be even better: we have voltage-ranges for mmc-spi case, see Documentation/powerpc/dts-bindings/mmc-spi-slot.txt. If voltage-ranges specified, then we use it, not capabilities register. For p4080 it will be 'voltage-ranges = 3200 3400;'. So, with voltage-ranges we can do fine grained VDD control without introducing anything new. As for implementation, you might just factor out voltage-ranges parsing from drivers/mmc/host/of_mmc_spi.c, and then in sdhci driver you could do. if (host-ocr_avail) mmc-ocr_avail = host-ocr_avail. clk = of_get_property(np, clock-frequency, size); if (clk size == sizeof(*clk) *clk) of_host-clock = *clk; diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 1424d08..a667790 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1699,6 +1699,14 @@ int sdhci_add_host(struct sdhci_host *host) caps = sdhci_readl(host, SDHCI_CAPABILITIES); + /* Workaround for P4080 host controller capabilities + * 1.8V and 3.0V do not supported*/ + if (host-quirks SDHCI_QUIRK_QORIQ_NO_VDD_180) The point of making NO_VDD stuff is to make these quirks chip-agnostic. Ideally, sdhci.c should never know about particular chips. So, you shouldn't name quirks with QORIQ. -- Anton Vorontsov email: cbouatmai...@gmail.com irc://irc.freenode.net/bd2 ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
