From cf2b5eea1ea0ff9b3184bc6771bcb93a9fdcd1d9 Mon Sep 17 00:00:00 2001 From: Arindam Nath Date: Thu, 5 May 2011 12:19:07 +0530 Subject: [PATCH] mmc: sdhci: add support for retuning mode 1 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. Tested by Zhangfei Gao with a Toshiba uhs card and general hs card, on mmp2 in SDMA mode. Signed-off-by: Arindam Nath Reviewed-by: Philip Rakity Tested-by: Philip Rakity Acked-by: Zhangfei Gao Signed-off-by: Chris Ball --- drivers/mmc/host/sdhci.c | 109 +++++++++++++++++++++++++++++++++++++- drivers/mmc/host/sdhci.h | 6 ++- include/linux/mmc/sdhci.h | 6 +++ 3 files changed, 118 insertions(+), 3 deletions(-) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 07cca557c4b..fa3301644b1 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 +1208,27 @@ 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); @@ -1673,6 +1694,37 @@ 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); @@ -1775,6 +1827,9 @@ 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; /* @@ -1848,6 +1903,20 @@ 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 * @@ -2122,6 +2191,14 @@ 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; @@ -2163,6 +2240,11 @@ 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; } @@ -2414,6 +2496,21 @@ 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 @@ -2559,9 +2656,15 @@ 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) @@ -2655,6 +2758,8 @@ 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 6b0a0ee9ac6..8ea11b7cf89 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 a88a799ed7c..e902618d68f 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 */ -- 2.41.0