Re: [PATCH] Revert "sdhci-of-esdhc: Support 8BIT bus width."

Joakim Tjernlund
2015-05-15T12:40:39Z

On Fri, 2015-05-15 at 15:42 +0800, Kevin Hao wrote:
> On Fri, May 15, 2015 at 07:24:55AM +0000, Joakim Tjernlund wrote:
> > Ahh, now I see. Drivers are supposed to call sdhci_set_bus_width instead of NULL:
> > Instead of reverting this add:
> >
> > diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
> > index 7a98a22..07b9df2 100644
> > --- a/drivers/mmc/host/sdhci-of-esdhc.c
> > +++ b/drivers/mmc/host/sdhci-of-esdhc.c
> > @@ -283,6 +283,7 @@ static const struct sdhci_ops sdhci_esdhc_ops = {
> > .get_min_clock = esdhc_of_get_min_clock,
> > .platform_init = esdhc_of_platform_init,
> > .adma_workaround = esdhci_of_adma_workaround,
> > + .set_bus_width = sdhci_set_bus_width,
> > .reset = esdhc_reset,
> > .set_uhs_signaling = sdhci_set_uhs_signaling,
> > };
> >
> > Should I repost the full "sdhci-of-esdhc: Support 8BIT bus width." with this fix added
> > of just the above fix?
>
> Sorry, this still don't work.

How about this one:

>From af6b18c056b6064424bd2ab1f9989bbadae5e701 Mon Sep 17 00:00:00 2001
From: Joakim Tjernlund <joakim.tjernlund@transmode.se>
Date: Mon, 20 Apr 2015 22:36:55 +0200
Subject: [PATCHv3] sdhci-of-esdhc: Support 8BIT bus width.

esdhc_readb()/esdhc_writeb() did not adjust for 8BIT.

Signed-off-by: Joakim Tjernlund <joakim.tjernlund@transmode.se>
---
v3 - v2 had a few misunderstandings in it w.r.t bus_with handling.
sdhci-of-esdhc.c appears to be a bit of a mess w.r.t to this so
here is v3 which only touchs esdhc_readb()/esdhc_writeb() so
8BIT is preserverd.

v2 - I had fogotten to add bus-width = <8> to my DTS.
Adding this simplified things
drivers/mmc/host/sdhci-of-esdhc.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index 1804bdb..233e38d 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -82,6 +82,10 @@ static u8 esdhc_readb(struct sdhci_host *host, int reg)
/* fixup the result */
ret &= ~SDHCI_CTRL_DMA_MASK;
ret |= dma_bits;
+
+ /* 8BIT is bit 29 in Control register */
+ ret |= ((ret << 3) & SDHCI_CTRL_8BITBUS);
+ ret &= ~(SDHCI_CTRL_8BITBUS >> 3);
}

return ret;
@@ -134,6 +138,10 @@ static void esdhc_writeb(struct sdhci_host *host, u8 val, int reg)
dma_bits);
val &= ~SDHCI_CTRL_DMA_MASK;
val |= in_be32(host->ioaddr + reg) & SDHCI_CTRL_DMA_MASK;
+
+ /* 8BIT is bit 29 in Control register */
+ val |= ((val & SDHCI_CTRL_8BITBUS) >> 3);
+ val = (val & ~SDHCI_CTRL_8BITBUS);
}

/* Prevent SDHCI core from writing reserved bits (e.g. HISPD). */
--
2.3.6