On 11 May 2015 at 08:46, yangbo.lu@xxxxxxxxxxxxx
<yangbo.lu@xxxxxxxxxxxxx> wrote:
> Thanks.
> The drivers/mmc/host/sdhci-of-esdhc.c also have same struct.
> static const struct sdhci_ops sdhci_esdhc_ops = {
> .read_l = esdhc_readl,
> .read_w = esdhc_readw,
> .read_b = esdhc_readb,
> .write_l = esdhc_writel,
> .write_w = esdhc_writew,
> .write_b = esdhc_writeb,
> .set_clock = esdhc_of_set_clock,
> .enable_dma = esdhc_of_enable_dma,
> .get_max_clock = esdhc_of_get_max_clock,
> .get_min_clock = esdhc_of_get_min_clock,
> .platform_init = esdhc_of_platform_init,
> .adma_workaround = esdhci_of_adma_workaround,
> .set_bus_width = esdhc_pltfm_set_bus_width,
> .reset = esdhc_reset,
> .set_uhs_signaling = esdhc_set_uhs_signaling,
> };
>
> Do you mean defining functions for little-endian and big-endian separately in sdhci-pltm.c?
> But it seems to need adding much code in drivers/mmc/host/sdhci-of-esdhc.c if don't use run-time checks.
On the other hand it will give you an optimized execution path. It's
better to check it once in ->probe() once, instead of every time.
Kind regards
Uffe
>
>
> -----Original Message-----
> From: Arnd Bergmann [mailto:arnd@xxxxxxxx]
> Sent: Friday, May 08, 2015 3:41 PM
> To: Lu Yangbo-B47093
> Cc: linux-mmc@xxxxxxxxxxxxxxx; chris@xxxxxxxxxx; ulf.hansson@xxxxxxxxxx
> Subject: Re: [v3, 2/6] mmc: sdhci-pltfm: support both LE and BE mode for SDHCI platform
>
> On Friday 08 May 2015 14:50:18 Yangbo Lu wrote:
>> -static inline u32 sdhci_be32bs_readl(struct sdhci_host *host, int
>> reg)
>> +static inline void sdhci_clrsetbits(struct sdhci_host *host, u32 mask,
>> + u32 val, int reg)
>> {
>> - return in_be32(host->ioaddr + reg);
>> + void __iomem *base = host->ioaddr + (reg & ~0x3);
>> + u32 shift = (reg & 0x3) * 8;
>> +
>> + if (host->mmc->big_endian_mode)
>> + iowrite32be(((ioread32be(base) & ~(mask << shift)) |
>> + (val << shift)), base);
>> + else
>> + iowrite32(((ioread32(base) & ~(mask << shift)) |
>> + (val << shift)), base);
>> }
>>
>>
>
> I think it would be better to use function pointers that are assigned at probe time than run-time checks here.
>
> Have a look at drivers/mmc/host/sdhci-of-hlwd.c:
>
> static const struct sdhci_ops sdhci_hlwd_ops = {
> .read_l = sdhci_be32bs_readl,
> .read_w = sdhci_be32bs_readw,
> .read_b = sdhci_be32bs_readb,
> .write_l = sdhci_hlwd_writel,
> .write_w = sdhci_hlwd_writew,
> .write_b = sdhci_hlwd_writeb,
> .set_clock = sdhci_set_clock,
> .set_bus_width = sdhci_set_bus_width,
> .reset = sdhci_reset,
> .set_uhs_signaling = sdhci_set_uhs_signaling, };
>
>
> You can copy this method into your own driver.
>
> Arnd
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