diff options
| -rw-r--r-- | drivers/mmc/host/omap.c | 89 |
1 files changed, 75 insertions, 14 deletions
diff --git a/drivers/mmc/host/omap.c b/drivers/mmc/host/omap.c index 7cc104ce0f0..3d59c5d81b3 100644 --- a/drivers/mmc/host/omap.c +++ b/drivers/mmc/host/omap.c @@ -161,9 +161,38 @@ struct mmc_omap_host { wait_queue_head_t slot_wq; int nr_slots; + struct timer_list clk_timer; + spinlock_t clk_lock; /* for changing enabled state */ + unsigned int fclk_enabled:1; + struct omap_mmc_platform_data *pdata; }; +void mmc_omap_fclk_offdelay(struct mmc_omap_slot *slot) +{ + unsigned long tick_ns; + + if (slot != NULL && slot->host->fclk_enabled && slot->fclk_freq > 0) { + tick_ns = (1000000000 + slot->fclk_freq - 1) / slot->fclk_freq; + ndelay(8 * tick_ns); + } +} + +void mmc_omap_fclk_enable(struct mmc_omap_host *host, unsigned int enable) +{ + unsigned long flags; + + spin_lock_irqsave(&host->clk_lock, flags); + if (host->fclk_enabled != enable) { + host->fclk_enabled = enable; + if (enable) + clk_enable(host->fclk); + else + clk_disable(host->fclk); + } + spin_unlock_irqrestore(&host->clk_lock, flags); +} + static void mmc_omap_select_slot(struct mmc_omap_slot *slot, int claimed) { struct mmc_omap_host *host = slot->host; @@ -180,32 +209,49 @@ static void mmc_omap_select_slot(struct mmc_omap_slot *slot, int claimed) host->mmc = slot->mmc; spin_unlock_irqrestore(&host->slot_lock, flags); no_claim: - clk_enable(host->fclk); + del_timer(&host->clk_timer); + if (host->current_slot != slot || !claimed) + mmc_omap_fclk_offdelay(host->current_slot); + if (host->current_slot != slot) { + OMAP_MMC_WRITE(host, CON, slot->saved_con & 0xFC00); if (host->pdata->switch_slot != NULL) host->pdata->switch_slot(mmc_dev(slot->mmc), slot->id); host->current_slot = slot; } - /* Doing the dummy read here seems to work around some bug - * at least in OMAP24xx silicon where the command would not - * start after writing the CMD register. Sigh. */ - OMAP_MMC_READ(host, CON); + if (claimed) { + mmc_omap_fclk_enable(host, 1); + + /* Doing the dummy read here seems to work around some bug + * at least in OMAP24xx silicon where the command would not + * start after writing the CMD register. Sigh. */ + OMAP_MMC_READ(host, CON); - OMAP_MMC_WRITE(host, CON, slot->saved_con); + OMAP_MMC_WRITE(host, CON, slot->saved_con); + } else + mmc_omap_fclk_enable(host, 0); } static void mmc_omap_start_request(struct mmc_omap_host *host, struct mmc_request *req); -static void mmc_omap_release_slot(struct mmc_omap_slot *slot) +static void mmc_omap_release_slot(struct mmc_omap_slot *slot, int clk_enabled) { struct mmc_omap_host *host = slot->host; unsigned long flags; int i; BUG_ON(slot == NULL || host->mmc == NULL); - clk_disable(host->fclk); + + if (clk_enabled) + /* Keeps clock running for at least 8 cycles on valid freq */ + mod_timer(&host->clk_timer, jiffies + HZ/10); + else { + del_timer(&host->clk_timer); + mmc_omap_fclk_offdelay(slot); + mmc_omap_fclk_enable(host, 0); + } spin_lock_irqsave(&host->slot_lock, flags); /* Check for any pending requests */ @@ -373,7 +419,7 @@ mmc_omap_xfer_done(struct mmc_omap_host *host, struct mmc_data *data) host->mrq = NULL; mmc = host->mmc; - mmc_omap_release_slot(host->current_slot); + mmc_omap_release_slot(host->current_slot, 1); mmc_request_done(mmc, data->mrq); return; } @@ -507,7 +553,7 @@ mmc_omap_cmd_done(struct mmc_omap_host *host, struct mmc_command *cmd) mmc_omap_abort_xfer(host, host->data); host->mrq = NULL; mmc = host->mmc; - mmc_omap_release_slot(host->current_slot); + mmc_omap_release_slot(host->current_slot, 1); mmc_request_done(mmc, cmd->mrq); } } @@ -538,7 +584,7 @@ static void mmc_omap_abort_command(struct work_struct *work) host->mrq = NULL; mmc = host->mmc; - mmc_omap_release_slot(host->current_slot); + mmc_omap_release_slot(host->current_slot, 1); mmc_request_done(mmc, cmd->mrq); } else mmc_omap_cmd_done(host, host->cmd); @@ -576,6 +622,14 @@ mmc_omap_sg_to_buf(struct mmc_omap_host *host) host->buffer_bytes_left = host->total_bytes_left; } +static void +mmc_omap_clk_timer(unsigned long data) +{ + struct mmc_omap_host *host = (struct mmc_omap_host *) data; + + mmc_omap_fclk_enable(host, 0); +} + /* PIO only */ static void mmc_omap_xfer_data(struct mmc_omap_host *host, int write) @@ -1149,14 +1203,16 @@ static void mmc_omap_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) struct mmc_omap_slot *slot = mmc_priv(mmc); struct mmc_omap_host *host = slot->host; int i, dsor; - - dsor = mmc_omap_calc_divisor(mmc, ios); + int clk_enabled; mmc_omap_select_slot(slot, 0); + dsor = mmc_omap_calc_divisor(mmc, ios); + if (ios->vdd != slot->vdd) slot->vdd = ios->vdd; + clk_enabled = 0; switch (ios->power_mode) { case MMC_POWER_OFF: mmc_omap_set_power(slot, 0, ios->vdd); @@ -1166,6 +1222,8 @@ static void mmc_omap_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) mmc_omap_set_power(slot, 1, ios->vdd); goto exit; case MMC_POWER_ON: + mmc_omap_fclk_enable(host, 1); + clk_enabled = 1; dsor |= 1 << 11; break; } @@ -1194,7 +1252,7 @@ static void mmc_omap_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) } exit: - mmc_omap_release_slot(slot); + mmc_omap_release_slot(slot, clk_enabled); } static const struct mmc_host_ops mmc_omap_ops = { @@ -1335,6 +1393,9 @@ static int __init mmc_omap_probe(struct platform_device *pdev) setup_timer(&host->cmd_abort_timer, mmc_omap_cmd_timer, (unsigned long) host); + spin_lock_init(&host->clk_lock); + setup_timer(&host->clk_timer, mmc_omap_clk_timer, (unsigned long) host); + spin_lock_init(&host->dma_lock); setup_timer(&host->dma_timer, mmc_omap_dma_timer, (unsigned long) host); spin_lock_init(&host->slot_lock); |