On Thu, May 5, 2011 at 2:49 AM, Arindam Nath <arindam.nath@xxxxxxx> wrote:
> Host Controller v3.00 can support retuning modes 1,2 or 3 depending on
> the bits 46-47 of the Capabilities register. Also, the timer count for
> retuning is indicated by bits 40-43 of the same register. We initialize
> timer_list for retuning the first time we execute tuning procedure. This
> condition is indicated by SDHCI_NEEDS_RETUNING not being set. Since
> retuning mode 1 sets a limit of 4MB on the maximum data length, we set
> max_blk_count appropriately. Once the tuning timer expires, we set
> SDHCI_NEEDS_RETUNING flag, and if the flag is set, we execute tuning
> procedure before sending the next command. We need to restore mmc_request
> structure after executing retuning procedure since host->mrq is used
> inside the procedure to send CMD19. We also disable and re-enable this
> flag during suspend and resume respectively, as per the spec v3.00.
>
> Signed-off-by: Arindam Nath <arindam.nath@xxxxxxx>
> Reviewed-by: Philip Rakity <prakity@xxxxxxxxxxx>
> Tested-by: Philip Rakity <prakity@xxxxxxxxxxx>
Acked-by: Zhangfei Gao<zhangfei.gao@xxxxxxxxxxx>
Verified with Toshiba uhs card and general hs card, on mmp2 in SDMA mode.
> ---
> drivers/mmc/host/sdhci.c | 113 ++++++++++++++++++++++++++++++++++++++++++++-
> drivers/mmc/host/sdhci.h | 6 ++-
> include/linux/mmc/sdhci.h | 6 ++
> 3 files changed, 122 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 8ed2e1b..3c04547 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -46,6 +46,8 @@ static void sdhci_finish_data(struct sdhci_host *);
>
> static void sdhci_send_command(struct sdhci_host *, struct mmc_command *);
> static void sdhci_finish_command(struct sdhci_host *);
> +static int sdhci_execute_tuning(struct mmc_host *mmc);
> +static void sdhci_tuning_timer(unsigned long data);
>
> static void sdhci_dumpregs(struct sdhci_host *host)
> {
> @@ -1206,8 +1208,28 @@ static void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
> if (!present || host->flags & SDHCI_DEVICE_DEAD) {
> host->mrq->cmd->error = -ENOMEDIUM;
> tasklet_schedule(&host->finish_tasklet);
> - } else
> + } else {
> + u32 present_state;
> +
> + present_state = sdhci_readl(host, SDHCI_PRESENT_STATE);
> + /*
> + * Check if the re-tuning timer has already expired and there
> + * is no on-going data transfer. If so, we need to execute
> + * tuning procedure before sending command.
> + */
> + if ((host->flags & SDHCI_NEEDS_RETUNING) &&
> + !(present_state & (SDHCI_DOING_WRITE |
> + SDHCI_DOING_READ))) {
> + spin_unlock_irqrestore(&host->lock, flags);
> + sdhci_execute_tuning(mmc);
> + spin_lock_irqsave(&host->lock, flags);
> +
> + /* Restore original mmc_request structure */
> + host->mrq = mrq;
> + }
> +
> sdhci_send_command(host, mrq->cmd);
> + }
>
> mmiowb();
> spin_unlock_irqrestore(&host->lock, flags);
> @@ -1679,6 +1701,37 @@ static int sdhci_execute_tuning(struct mmc_host *mmc)
> }
>
> out:
> + /*
> + * If this is the very first time we are here, we start the retuning
> + * timer. Since only during the first time, SDHCI_NEEDS_RETUNING
> + * flag won't be set, we check this condition before actually starting
> + * the timer.
> + */
> + if (!(host->flags & SDHCI_NEEDS_RETUNING) && host->tuning_count &&
> + (host->tuning_mode == SDHCI_TUNING_MODE_1)) {
> + mod_timer(&host->tuning_timer, jiffies + host->tuning_count *
> + HZ);
> + /* Tuning mode 1 limits the maximum data length to 4MB */
> + mmc->max_blk_count = (4 * 1024 * 1024) / mmc->max_blk_size;
> + } else {
> + host->flags &= ~SDHCI_NEEDS_RETUNING;
> + /* Reload the new initial value for timer */
> + if (host->tuning_mode == SDHCI_TUNING_MODE_1)
> + mod_timer(&host->tuning_timer, jiffies +
> + host->tuning_count * HZ);
> + }
> +
> + /*
> + * In case tuning fails, host controllers which support re-tuning can
> + * try tuning again at a later time, when the re-tuning timer expires.
> + * So for these controllers, we return 0. Since there might be other
> + * controllers who do not have this capability, we return error for
> + * them.
> + */
> + if (err && host->tuning_count &&
> + (host->tuning_mode == SDHCI_TUNING_MODE_1))
> + err = 0;
> +
> sdhci_clear_set_irqs(host, SDHCI_INT_DATA_AVAIL, ier);
> spin_unlock(&host->lock);
> enable_irq(host->irq);
> @@ -1781,6 +1834,10 @@ static void sdhci_tasklet_finish(unsigned long param)
>
> del_timer(&host->timer);
>
> + if (host->version >= SDHCI_SPEC_300)
> + del_timer(&host->tuning_timer);
> +
> +
> mrq = host->mrq;
>
> /*
> @@ -1854,6 +1911,20 @@ static void sdhci_timeout_timer(unsigned long data)
> spin_unlock_irqrestore(&host->lock, flags);
> }
>
> +static void sdhci_tuning_timer(unsigned long data)
> +{
> + struct sdhci_host *host;
> + unsigned long flags;
> +
> + host = (struct sdhci_host *)data;
> +
> + spin_lock_irqsave(&host->lock, flags);
> +
> + host->flags |= SDHCI_NEEDS_RETUNING;
> +
> + spin_unlock_irqrestore(&host->lock, flags);
> +}
> +
> /*****************************************************************************\
> * *
> * Interrupt handling *
> @@ -2128,6 +2199,15 @@ int sdhci_suspend_host(struct sdhci_host *host, pm_message_t state)
>
> sdhci_disable_card_detection(host);
>
> + /* Disable tuning since we are suspending */
> + if ((host->version >= SDHCI_SPEC_300) &&
> + host->tuning_count &&
> + (host->tuning_mode == SDHCI_TUNING_MODE_1)) {
> + host->flags &= ~SDHCI_NEEDS_RETUNING;
> + mod_timer(&host->tuning_timer, jiffies +
> + host->tuning_count * HZ);
> + }
> +
> ret = mmc_suspend_host(host->mmc);
> if (ret)
> return ret;
> @@ -2169,6 +2249,12 @@ int sdhci_resume_host(struct sdhci_host *host)
> ret = mmc_resume_host(host->mmc);
> sdhci_enable_card_detection(host);
>
> + /* Set the re-tuning expiration flag */
> + if ((host->version >= SDHCI_SPEC_300) &&
> + host->tuning_count &&
> + (host->tuning_mode == SDHCI_TUNING_MODE_1))
> + host->flags |= SDHCI_NEEDS_RETUNING;
> +
> return ret;
> }
>
> @@ -2420,6 +2506,21 @@ int sdhci_add_host(struct sdhci_host *host)
> if (caps[1] & SDHCI_DRIVER_TYPE_D)
> mmc->caps |= MMC_CAP_DRIVER_TYPE_D;
>
> + /* Initial value for re-tuning timer count */
> + host->tuning_count = (caps[1] & SDHCI_RETUNING_TIMER_COUNT_MASK) >>
> + SDHCI_RETUNING_TIMER_COUNT_SHIFT;
> +
> + /*
> + * In case Re-tuning Timer is not disabled, the actual value of
> + * re-tuning timer will be 2 ^ (n - 1).
> + */
> + if (host->tuning_count)
> + host->tuning_count = 1 << (host->tuning_count - 1);
> +
> + /* Re-tuning mode supported by the Host Controller */
> + host->tuning_mode = (caps[1] & SDHCI_RETUNING_MODE_MASK) >>
> + SDHCI_RETUNING_MODE_SHIFT;
> +
> ocr_avail = 0;
> /*
> * According to SD Host Controller spec v3.00, if the Host System
> @@ -2565,9 +2666,15 @@ int sdhci_add_host(struct sdhci_host *host)
>
> setup_timer(&host->timer, sdhci_timeout_timer, (unsigned long)host);
>
> - if (host->version >= SDHCI_SPEC_300)
> + if (host->version >= SDHCI_SPEC_300) {
> init_waitqueue_head(&host->buf_ready_int);
>
> + /* Initialize re-tuning timer */
> + init_timer(&host->tuning_timer);
> + host->tuning_timer.data = (unsigned long)host;
> + host->tuning_timer.function = sdhci_tuning_timer;
> + }
> +
> ret = request_irq(host->irq, sdhci_irq, IRQF_SHARED,
> mmc_hostname(mmc), host);
> if (ret)
> @@ -2661,6 +2768,8 @@ void sdhci_remove_host(struct sdhci_host *host, int dead)
> free_irq(host->irq, host);
>
> del_timer_sync(&host->timer);
> + if (host->version >= SDHCI_SPEC_300)
> + del_timer_sync(&host->tuning_timer);
>
> tasklet_kill(&host->card_tasklet);
> tasklet_kill(&host->finish_tasklet);
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 0208164..fb74dc6 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -191,7 +191,11 @@
> #define SDHCI_DRIVER_TYPE_A 0x00000010
> #define SDHCI_DRIVER_TYPE_C 0x00000020
> #define SDHCI_DRIVER_TYPE_D 0x00000040
> -#define SDHCI_USE_SDR50_TUNING 0x00002000
> +#define SDHCI_RETUNING_TIMER_COUNT_MASK 0x00000F00
> +#define SDHCI_RETUNING_TIMER_COUNT_SHIFT 8
> +#define SDHCI_USE_SDR50_TUNING 0x00002000
> +#define SDHCI_RETUNING_MODE_MASK 0x0000C000
> +#define SDHCI_RETUNING_MODE_SHIFT 14
> #define SDHCI_CLOCK_MUL_MASK 0x00FF0000
> #define SDHCI_CLOCK_MUL_SHIFT 16
>
> diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h
> index a88a799..e902618 100644
> --- a/include/linux/mmc/sdhci.h
> +++ b/include/linux/mmc/sdhci.h
> @@ -112,6 +112,7 @@ struct sdhci_host {
> #define SDHCI_REQ_USE_DMA (1<<2) /* Use DMA for this req. */
> #define SDHCI_DEVICE_DEAD (1<<3) /* Device unresponsive */
> #define SDHCI_SDR50_NEEDS_TUNING (1<<4) /* SDR50 needs tuning */
> +#define SDHCI_NEEDS_RETUNING (1<<5) /* Host needs retuning */
>
> unsigned int version; /* SDHCI spec. version */
>
> @@ -152,6 +153,11 @@ struct sdhci_host {
> wait_queue_head_t buf_ready_int; /* Waitqueue for Buffer Read Ready interrupt */
> unsigned int tuning_done; /* Condition flag set when CMD19 succeeds */
>
> + unsigned int tuning_count; /* Timer count for re-tuning */
> + unsigned int tuning_mode; /* Re-tuning mode supported by host */
> +#define SDHCI_TUNING_MODE_1 0
> + struct timer_list tuning_timer; /* Timer for tuning */
> +
> unsigned long private[0] ____cacheline_aligned;
> };
> #endif /* __SDHCI_H */
> --
> 1.7.1
>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
