Re: [PATCH 2/2] mmc: sdhci: Use sdhci-caps-mask and sdhci-caps to change the caps read during __sdhci_read_caps

From: Adrian Hunter
Date: Wed Nov 02 2016 - 04:44:34 EST


On 28/10/16 18:56, Zach Brown wrote:
> The sdhci capabilities register can be incorrect. The sdhci-caps-mask
> and sdhci-caps dt properties specify which bits of the register are
> incorrect and what their values should be. This patch makes the sdhci
> driver use those properties to correct the caps during
> __sdhci_read_caps.
>
> During __sdhci_read_caps
> Use the sdhci-caps-mask property to turn off the incorrect bits of the
> sdhci register after reading them.
> Use the sdhci-caps to turn on bits after using sdhci-caps-mask to turn
> off the incorrect ones.
>
> Signed-off-by: Zach Brown <zach.brown@xxxxxx>

Apart from minor style issue:

Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>

> ---
> drivers/mmc/host/sdhci.c | 24 ++++++++++++++++++++++--
> 1 file changed, 22 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 1e25b01..d5feae4 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -22,6 +22,7 @@
> #include <linux/scatterlist.h>
> #include <linux/regulator/consumer.h>
> #include <linux/pm_runtime.h>
> +#include <linux/of.h>
>
> #include <linux/leds.h>
>
> @@ -2991,6 +2992,8 @@ static int sdhci_set_dma_mask(struct sdhci_host *host)
> void __sdhci_read_caps(struct sdhci_host *host, u16 *ver, u32 *caps, u32 *caps1)
> {
> u16 v;
> + u64 dt_caps_mask = 0;
> + u64 dt_caps = 0;
>
> if (host->read_caps)
> return;
> @@ -3005,18 +3008,35 @@ void __sdhci_read_caps(struct sdhci_host *host, u16 *ver, u32 *caps, u32 *caps1)
>
> sdhci_do_reset(host, SDHCI_RESET_ALL);
>
> + of_property_read_u64(mmc_dev(host->mmc)->of_node,
> + "sdhci-caps-mask", &dt_caps_mask);
> + of_property_read_u64(mmc_dev(host->mmc)->of_node,
> + "sdhci-caps", &dt_caps);
> +
> v = ver ? *ver : sdhci_readw(host, SDHCI_HOST_VERSION);
> host->version = (v & SDHCI_SPEC_VER_MASK) >> SDHCI_SPEC_VER_SHIFT;
>
> if (host->quirks & SDHCI_QUIRK_MISSING_CAPS)
> return;
>
> - host->caps = caps ? *caps : sdhci_readl(host, SDHCI_CAPABILITIES);
> + if (caps)
> + host->caps = *caps;
> + else {

All branches of 'if' should have {}.
i.e. refer results of ./scripts/checkpatch.pl --strict

> + host->caps = sdhci_readl(host, SDHCI_CAPABILITIES);
> + host->caps &= ~lower_32_bits(dt_caps_mask);
> + host->caps |= lower_32_bits(dt_caps);
> + }
>
> if (host->version < SDHCI_SPEC_300)
> return;
>
> - host->caps1 = caps1 ? *caps1 : sdhci_readl(host, SDHCI_CAPABILITIES_1);
> + if (caps1)
> + host->caps1 = *caps1;
> + else {

Ditto

> + host->caps1 = sdhci_readl(host, SDHCI_CAPABILITIES_1);
> + host->caps1 &= ~upper_32_bits(dt_caps_mask);
> + host->caps1 |= upper_32_bits(dt_caps);
> + }
> }
> EXPORT_SYMBOL_GPL(__sdhci_read_caps);
>
>