Re: [PATCH v2 2/2] sdhci-of-arasan: Set controller to test mode when Card Detection is broken.

[Mike Looijmans <mike.looijmans@topic.nl>]

On 26-08-16 01:01, Zach Brown wrote:
> The sdhci controller on xilinx zynq devices will not function unless
> the CD bit is provided. http://www.xilinx.com/support/answers/61064.html
> In cases where it is impossible to provide the CD bit in hardware,
> setting the controller to test mode and then setting inserted to true
> will get the controller to function without the CD bit.
>
> When the device has the property broken-cd the driver changes the
> controller to test mode and sets test inserted to true to make the
> controller function.
>
> Signed-off-by: Zach Brown <zach.brown@ni.com>
> ---
>   drivers/mmc/host/sdhci-of-arasan.c | 17 ++++++++++++++++-
>   drivers/mmc/host/sdhci.h           |  2 ++
>   2 files changed, 18 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
> index e0f193f..3798a3b 100644
> --- a/drivers/mmc/host/sdhci-of-arasan.c
> +++ b/drivers/mmc/host/sdhci-of-arasan.c
> @@ -26,6 +26,7 @@
>   #include <linux/phy/phy.h>
>   #include <linux/regmap.h>
>   #include "sdhci-pltfm.h"
> +#include <linux/of.h>

Not needed.

>   #define SDHCI_ARASAN_CLK_CTRL_OFFSET	0x2c
>   #define SDHCI_ARASAN_VENDOR_REGISTER	0x78
> @@ -203,12 +204,26 @@ static void sdhci_arasan_hs400_enhanced_strobe(struct mmc_host *mmc,
>   	writel(vendor, host->ioaddr + SDHCI_ARASAN_VENDOR_REGISTER);
>   }
>
> +void sdhci_arasan_reset(struct sdhci_host *host, u8 mask)
> +{
> +	u8 ctrl;
> +
> +	sdhci_reset(host, mask);
> +
> +	if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) {
> +		ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
> +		ctrl |= SDHCI_CTRL_CDTEST_INS |
> +			SDHCI_CTRL_CDTEST_EN;
> +		sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
> +	}
> +}
> +
>   static struct sdhci_ops sdhci_arasan_ops = {
>   	.set_clock = sdhci_arasan_set_clock,
>   	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
>   	.get_timeout_clock = sdhci_arasan_get_timeout_clock,
>   	.set_bus_width = sdhci_set_bus_width,
> -	.reset = sdhci_reset,
> +	.reset = sdhci_arasan_reset,
>   	.set_uhs_signaling = sdhci_set_uhs_signaling,
>   };
>
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 0411c9f..8d92d6e9 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -84,6 +84,8 @@
>   #define   SDHCI_CTRL_ADMA32	0x10
>   #define   SDHCI_CTRL_ADMA64	0x18
>   #define   SDHCI_CTRL_8BITBUS	0x20
> +#define  SDHCI_CTRL_CDTEST_INS   0x40
> +#define  SDHCI_CTRL_CDTEST_EN     0x80
>
>   #define SDHCI_POWER_CONTROL	0x29
>   #define  SDHCI_POWER_ON		0x01

Looks okay, tested it and appears to work just as well as a tie-off in logic.

Tested-by: mike.looijmans@topic.nl