Messages in this thread |  | | Date | Wed, 10 Jun 2026 00:31:33 +1000 | | Subject | Re: [RFC 3/4] mmc: sdhci-esdhc-mcf: do not use readl()/writel() on ColdFire | | From | Greg Ungerer <> |
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On 12/5/26 01:11, Ulf Hansson wrote: > On Wed, 6 May 2026 at 16:34, Greg Ungerer <gerg@kernel.org> wrote: >> >> From: Greg Ungerer <gerg@linux-m68k.org> >> >> The implementation of the readX() and writeX() family of IO access >> functions is non-standard on ColdFire platforms. They check the supplied >> IO address and will return either big or little endian results based on >> that check. This is non-standard, they are expected to always return >> little-endian byte ordered data. Unfortunately this behavior also means >> that ioreadX()/iowroteX() and their big-endian counter parts >> ioreadXbe()/iowriteXbe() are wrong. This is now in the process of being >> cleaned up and fixed. >> >> Change the use of the readX() and writeX() access functions in this driver >> to use the recently defined specific ColdFire internal SoC hardware IO >> access functions mcf_read8()/mcf_read16()/mcf_read32() and >> mcf_write8()/mcf_write16()/mcf_write32(). >> >> There is no functional change to the driver. Though it does have the >> effect of making the IO access slightly more efficient, since there is >> no longer a need to do the address check at every register access. >> >> Signed-off-by: Greg Ungerer <gerg@linux-m68k.org> >> --- >> drivers/mmc/host/sdhci-esdhc-mcf.c | 24 ++++++++++++------------ >> 1 file changed, 12 insertions(+), 12 deletions(-) >> >> Note that the patches to introduce mcf_readX() and mcf_writeX functions >> are not in mainline yet. They are currently in the m68knommu git tree >> for-next branch, and so should also be in linux-next. > > Okay, so please resubmit the $subject patch when the mcf_readX|writeX > functions are available in a v7.x-rc so I can pick it up. > > Another option is if someone can host an immutable branch for me to > pull in the changes for mcf_readX|writeX.
Those changes are now on an immutable branch at:
git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu.git cf-internal-io branch
I will follow up after 7.2-rc1 is out with this patch set as well.
Regards Greg
> Kind regards > Uffe > >> >> diff --git a/drivers/mmc/host/sdhci-esdhc-mcf.c b/drivers/mmc/host/sdhci-esdhc-mcf.c >> index 375fce5639d7..6853521e8b2c 100644 >> --- a/drivers/mmc/host/sdhci-esdhc-mcf.c >> +++ b/drivers/mmc/host/sdhci-esdhc-mcf.c >> @@ -55,7 +55,7 @@ static inline void esdhc_clrset_be(struct sdhci_host *host, >> if (reg == SDHCI_HOST_CONTROL) >> val |= ESDHC_PROCTL_D3CD; >> >> - writel((readl(base) & ~mask) | val, base); >> + mcf_write32((mcf_read32(base) & ~mask) | val, base); >> } >> >> /* >> @@ -71,7 +71,7 @@ static void esdhc_mcf_writeb_be(struct sdhci_host *host, u8 val, int reg) >> if (reg == SDHCI_HOST_CONTROL) { >> u32 host_ctrl = ESDHC_DEFAULT_HOST_CONTROL; >> u8 dma_bits = (val & SDHCI_CTRL_DMA_MASK) >> 3; >> - u8 tmp = readb(host->ioaddr + SDHCI_HOST_CONTROL + 1); >> + u8 tmp = mcf_read8(host->ioaddr + SDHCI_HOST_CONTROL + 1); >> >> tmp &= ~0x03; >> tmp |= dma_bits; >> @@ -82,12 +82,12 @@ static void esdhc_mcf_writeb_be(struct sdhci_host *host, u8 val, int reg) >> */ >> host_ctrl |= val; >> host_ctrl |= (dma_bits << 8); >> - writel(host_ctrl, host->ioaddr + SDHCI_HOST_CONTROL); >> + mcf_write32(host_ctrl, host->ioaddr + SDHCI_HOST_CONTROL); >> >> return; >> } >> >> - writel((readl(base) & mask) | (val << shift), base); >> + mcf_write32((mcf_read32(base) & mask) | (val << shift), base); >> } >> >> static void esdhc_mcf_writew_be(struct sdhci_host *host, u16 val, int reg) >> @@ -110,24 +110,24 @@ static void esdhc_mcf_writew_be(struct sdhci_host *host, u16 val, int reg) >> * As for the fsl driver, >> * we have to set the mode in a single write here. >> */ >> - writel(val << 16 | mcf_data->aside, >> + mcf_write32(val << 16 | mcf_data->aside, >> host->ioaddr + SDHCI_TRANSFER_MODE); >> return; >> } >> >> - writel((readl(base) & mask) | (val << shift), base); >> + mcf_write32((mcf_read32(base) & mask) | (val << shift), base); >> } >> >> static void esdhc_mcf_writel_be(struct sdhci_host *host, u32 val, int reg) >> { >> - writel(val, host->ioaddr + reg); >> + mcf_write32(val, host->ioaddr + reg); >> } >> >> static u8 esdhc_mcf_readb_be(struct sdhci_host *host, int reg) >> { >> if (reg == SDHCI_HOST_CONTROL) { >> u8 __iomem *base = host->ioaddr + (reg & ~3); >> - u16 val = readw(base + 2); >> + u16 val = mcf_read16(base + 2); >> u8 dma_bits = (val >> 5) & SDHCI_CTRL_DMA_MASK; >> u8 host_ctrl = val & 0xff; >> >> @@ -137,7 +137,7 @@ static u8 esdhc_mcf_readb_be(struct sdhci_host *host, int reg) >> return host_ctrl; >> } >> >> - return readb(host->ioaddr + (reg ^ 0x3)); >> + return mcf_read8(host->ioaddr + (reg ^ 0x3)); >> } >> >> static u16 esdhc_mcf_readw_be(struct sdhci_host *host, int reg) >> @@ -149,14 +149,14 @@ static u16 esdhc_mcf_readw_be(struct sdhci_host *host, int reg) >> if (reg == SDHCI_HOST_VERSION) >> reg -= 2; >> >> - return readw(host->ioaddr + (reg ^ 0x2)); >> + return mcf_read16(host->ioaddr + (reg ^ 0x2)); >> } >> >> static u32 esdhc_mcf_readl_be(struct sdhci_host *host, int reg) >> { >> u32 val; >> >> - val = readl(host->ioaddr + reg); >> + val = mcf_read32(host->ioaddr + reg); >> >> /* >> * RM (25.3.9) sd pin clock must never exceed 25Mhz. >> @@ -245,7 +245,7 @@ static void esdhc_mcf_pltfm_set_clock(struct sdhci_host *host, >> * fvco = fsys * outdvi1 + 1 >> * fshdc = fvco / outdiv3 + 1 >> */ >> - temp = readl(pll_dr); >> + temp = mcf_read32(pll_dr); >> fsys = pltfm_host->clock; >> fvco = fsys * ((temp & 0x1f) + 1); >> fesdhc = fvco / (((temp >> 10) & 0x1f) + 1); >> -- >> 2.54.0 >> >> >
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