[PATCH 2/2] sdhci-of-arasan: Add quirk and device tree parameter to fake CD bit

Adrian Hunter
2016-08-25T08:50:07Z

On 25/08/16 02:23, 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 with out the cd bit.

with out -> without

>
> The device property "fake-cd" will let the arasan driver know it needs
> to fake the cd bit for the controller inorder for the controller to

inorder -> in order

> function with a SD card that does not provide the CD bit.

Please use either 'cd' or 'CD' consistently.

>
> Signed-off-by: Zach Brown <zach.brown@ni.com>
> ---
> drivers/mmc/host/sdhci-of-arasan.c | 23 ++++++++++++++++++++++-
> drivers/mmc/host/sdhci.h | 4 ++++
> 2 files changed, 26 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
> index e0f193f..a74bcf5 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>
>
> #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->quirks2 & SDHCI_QUIRK2_NEED_FAKE_CD) {
> + ctrl = sdhci_readl(host, SDHCI_HOST_CONTROL);

Is there a reason this is sdhci_readl instead of sdhci_readb

> + ctrl |= SDHCI_CTRL_CD_TEST_INSERTED |
> + SDHCI_CTRL_CD_TEST_ENABLE;

Please indent SDHCI_CTRL_CD_TEST_ENABLE

> + 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,
> };
>
> @@ -516,6 +531,12 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
> }
>
> sdhci_get_of_property(pdev);
> +
> + if (of_get_property(pdev->dev.of_node, "fake-cd", NULL))
> + host->quirks2 |= SDHCI_QUIRK2_NEED_FAKE_CD;

Please don't use a quirk bit for this. Instead add a flag to, for example,
struct sdhci_arasan_data.

> +
> + pltfm_host = sdhci_priv(host);
> + pltfm_host->priv = sdhci_arasan;

These 2 lines don't belong.

> pltfm_host->clk = clk_xin;
>
> sdhci_arasan_update_baseclkfreq(host);
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 0411c9f..ff3c8ba 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_CD_TEST_INSERTED 0x40
> +#define SDHCI_CTRL_CD_TEST_ENABLE 0x80

For the sake of neatness, let's make these a little more abbreviated, say:

SDHCI_CTRL_CDTEST_INS
SDHCI_CTRL_CDTEST_EN

>
> #define SDHCI_POWER_CONTROL 0x29
> #define SDHCI_POWER_ON 0x01
> @@ -422,6 +424,8 @@ struct sdhci_host {
> #define SDHCI_QUIRK2_ACMD23_BROKEN (1<<14)
> /* Broken Clock divider zero in controller */
> #define SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN (1<<15)
> +/* Controller needs the cd bit faked */
> +#define SDHCI_QUIRK2_NEED_FAKE_CD (1<<16)
>
> int irq; /* Device IRQ */
> void __iomem *ioaddr; /* Mapped address */
>