On Dec 13, 2011, at 6:18 PM, <r66093@xxxxxxxxxxxxx> wrote:
> From: Jerry Huang <Chang-Ming.Huang@xxxxxxxxxxxxx>
>
> Add callback function sdhci_get_cd to detect the card.
> And one new callback added to implement the card detect in sdhci struncture.
> If special platform has the card detect callback, it will return the card
> state, the value zero is for absent cardi and one is for present card.
> If the controller don't support card detect, sdhci_get_cd will return -ENOSYS.
>
> Signed-off-by: Jerry Huang <Chang-Ming.Huang@xxxxxxxxxxxxx>
> CC: Chris Ball <cjb@xxxxxxxxxx>
> ---
> changes for v2:
> - when controller don't support get_cd, return -ENOSYS
> - add new callback for sdhci to detect the card
> - add the CC
> changes for v3:
> - use pin_lock only when get_cd defined
> changes for v4:
> - enalbe the controller clock in platform, instead of core
> changes for v5:
> - remove the copyright
>
> drivers/mmc/host/sdhci.c | 21 ++++++++++++++++++++++
> drivers/mmc/host/sdhci.h | 2 ++
> 2 files changed, 23 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 6d8eea3..fbe2f46 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1518,6 +1519,26 @@ static int sdhci_get_ro(struct mmc_host *mmc)
> return ret;
> }
>
> +/* Return values for the sdjco_get_cd callback:
> + * 0 for a absent card
> + * 1 for a present card
> + * -ENOSYS when not supported (equal to NULL callback)
> + */
> +static int sdhci_get_cd(struct mmc_host *mmc)
> +{
> + struct sdhci_host *host = mmc_priv(mmc);
> + unsigned long flags;
> + int present = -ENOSYS;
> +
> + if (host->ops->get_cd) {
> + spin_lock_irqsave(&host->lock, flags);
> + present = host->ops->get_cd(host);
> + spin_unlock_irqrestore(&host->lock, flags);
> + }
> +
> + return present;
> +}
In static void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
there is code below to handle broken card detect.
1257
1258 /* If polling, assume that the card is always present. */
1259 if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION)
1260 present = true;
1261 else
1262 present = sdhci_readl(host, SDHCI_PRESENT_STATE) &
1263 SDHCI_CARD_PRESENT;
The problem with this code is that it assumes broken card detect is broken since
the present state register cannot be read.
would it make more sense to do something like
if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) {
if (host->ops->get_cd)
present = present = host->ops->get_cd(host);
else
present = true;
and adjust the code in host->ops->get_cd() to not -ENOSYS.
Philip
> +
> static void sdhci_enable_sdio_irq_nolock(struct sdhci_host *host, int enable)
> {
> if (host->flags & SDHCI_DEVICE_DEAD)
> @@ -1884,6 +1905,7 @@ static const struct mmc_host_ops sdhci_ops = {
> .request = sdhci_request,
> .set_ios = sdhci_set_ios,
> .get_ro = sdhci_get_ro,
> + .get_cd = sdhci_get_cd,
> .hw_reset = sdhci_hw_reset,
> .enable_sdio_irq = sdhci_enable_sdio_irq,
> .start_signal_voltage_switch = sdhci_start_signal_voltage_switch,
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 0a5b654..82f4d27 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -69,6 +69,7 @@
> #define SDHCI_SPACE_AVAILABLE 0x00000400
> #define SDHCI_DATA_AVAILABLE 0x00000800
> #define SDHCI_CARD_PRESENT 0x00010000
> +#define SDHCI_CARD_CDPL 0x00040000
> #define SDHCI_WRITE_PROTECT 0x00080000
> #define SDHCI_DATA_LVL_MASK 0x00F00000
> #define SDHCI_DATA_LVL_SHIFT 20
> @@ -261,6 +262,7 @@ struct sdhci_ops {
>
> void (*set_clock)(struct sdhci_host *host, unsigned int clock);
>
> + int (*get_cd)(struct sdhci_host *host);
> int (*enable_dma)(struct sdhci_host *host);
> unsigned int (*get_max_clock)(struct sdhci_host *host);
> unsigned int (*get_min_clock)(struct sdhci_host *host);
> --
> 1.7.5.4
>
>
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