From dd498effcfa6a196ba097adae3c5aa641115df88 Mon Sep 17 00:00:00 2001 From: Denis Karpov Date: Tue, 22 Sep 2009 16:44:49 -0700 Subject: omap_hsmmc: support for deeper power saving states Support for multi-level dynamic power saving states in omap_hsmmc (ENABLED->DISABLED->OFF). In the "deepest" state (OFF) we switch off the voltage regulators. Signed-off-by: Denis Karpov Signed-off-by: Adrian Hunter Acked-by: Matt Fleming Cc: Ian Molton Cc: "Roberto A. Foglietta" Cc: Jarkko Lavinen Cc: Denis Karpov Cc: Pierre Ossman Cc: Philip Langdale Cc: "Madhusudhan" Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/mmc/host/omap_hsmmc.c | 245 ++++++++++++++++++++++++++++++++++++------ 1 file changed, 215 insertions(+), 30 deletions(-) (limited to 'drivers/mmc/host/omap_hsmmc.c') diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c index a20c38385d2a..016914c2c4e7 100644 --- a/drivers/mmc/host/omap_hsmmc.c +++ b/drivers/mmc/host/omap_hsmmc.c @@ -113,6 +113,10 @@ #define OMAP_MMC_MASTER_CLOCK 96000000 #define DRIVER_NAME "mmci-omap-hs" +/* Timeouts for entering power saving states on inactivity, msec */ +#define OMAP_MMC_DISABLED_TIMEOUT 100 +#define OMAP_MMC_OFF_TIMEOUT 1000 + /* * One controller can have multiple slots, like on some omap boards using * omap.c controller driver. Luckily this is not currently done on any known @@ -157,6 +161,7 @@ struct mmc_omap_host { int dbclk_enabled; int response_busy; int context_loss; + int dpm_state; struct omap_mmc_platform_data *pdata; }; @@ -992,29 +997,6 @@ mmc_omap_prepare_data(struct mmc_omap_host *host, struct mmc_request *req) return 0; } -static int omap_mmc_enable(struct mmc_host *mmc) -{ - struct mmc_omap_host *host = mmc_priv(mmc); - int err; - - err = clk_enable(host->fclk); - if (err) - return err; - dev_dbg(mmc_dev(host->mmc), "mmc_fclk: enabled\n"); - omap_mmc_restore_ctx(host); - return 0; -} - -static int omap_mmc_disable(struct mmc_host *mmc, int lazy) -{ - struct mmc_omap_host *host = mmc_priv(mmc); - - omap_mmc_save_ctx(host); - clk_disable(host->fclk); - dev_dbg(mmc_dev(host->mmc), "mmc_fclk: disabled\n"); - return 0; -} - /* * Request function. for read/write operation */ @@ -1068,6 +1050,8 @@ static void omap_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) host->power_mode = ios->power_mode; } + /* FIXME: set registers based only on changes to ios */ + con = OMAP_HSMMC_READ(host->base, CON); switch (mmc->ios.bus_width) { case MMC_BUS_WIDTH_8: @@ -1140,7 +1124,10 @@ static void omap_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) else OMAP_HSMMC_WRITE(host->base, CON, con & ~OD); - mmc_host_lazy_disable(host->mmc); + if (host->power_mode == MMC_POWER_OFF) + mmc_host_disable(host->mmc); + else + mmc_host_lazy_disable(host->mmc); } static int omap_hsmmc_get_cd(struct mmc_host *mmc) @@ -1190,7 +1177,191 @@ static void omap_hsmmc_init(struct mmc_omap_host *host) set_sd_bus_power(host); } -static struct mmc_host_ops mmc_omap_ops = { +/* + * Dynamic power saving handling, FSM: + * ENABLED -> DISABLED -> OFF + * ^___________| | + * |______________________| + * + * ENABLED: mmc host is fully functional + * DISABLED: fclk is off + * OFF: fclk is off,voltage regulator is off + * + * Transition handlers return the timeout for the next state transition + * or negative error. + */ + +enum {ENABLED = 0, DISABLED, OFF}; + +/* Handler for [ENABLED -> DISABLED] transition */ +static int omap_mmc_enabled_to_disabled(struct mmc_omap_host *host) +{ + omap_mmc_save_ctx(host); + clk_disable(host->fclk); + host->dpm_state = DISABLED; + + dev_dbg(mmc_dev(host->mmc), "ENABLED -> DISABLED\n"); + + if (host->power_mode == MMC_POWER_OFF) + return 0; + + return msecs_to_jiffies(OMAP_MMC_OFF_TIMEOUT); +} + +/* Handler for [DISABLED -> OFF] transition */ +static int omap_mmc_disabled_to_off(struct mmc_omap_host *host) +{ + int new_state; + + dev_dbg(mmc_dev(host->mmc), "DISABLED -> OFF\n"); + + if (!mmc_try_claim_host(host->mmc)) + return 0; + + clk_enable(host->fclk); + + omap_mmc_restore_ctx(host); + + if ((host->mmc->caps & MMC_CAP_NONREMOVABLE) || + mmc_slot(host).card_detect || + (mmc_slot(host).get_cover_state && + mmc_slot(host).get_cover_state(host->dev, host->slot_id))) { + mmc_power_save_host(host->mmc); + new_state = OFF; + } else + new_state = DISABLED; + + OMAP_HSMMC_WRITE(host->base, ISE, 0); + OMAP_HSMMC_WRITE(host->base, IE, 0); + OMAP_HSMMC_WRITE(host->base, HCTL, + OMAP_HSMMC_READ(host->base, HCTL) & ~SDBP); + + clk_disable(host->fclk); + clk_disable(host->iclk); + clk_disable(host->dbclk); + + host->dpm_state = new_state; + + mmc_release_host(host->mmc); + + return 0; +} + +/* Handler for [DISABLED -> ENABLED] transition */ +static int omap_mmc_disabled_to_enabled(struct mmc_omap_host *host) +{ + int err; + + err = clk_enable(host->fclk); + if (err < 0) + return err; + + omap_mmc_restore_ctx(host); + + host->dpm_state = ENABLED; + + dev_dbg(mmc_dev(host->mmc), "DISABLED -> ENABLED\n"); + + return 0; +} + +/* Handler for [OFF -> ENABLED] transition */ +static int omap_mmc_off_to_enabled(struct mmc_omap_host *host) +{ + clk_enable(host->fclk); + clk_enable(host->iclk); + + if (clk_enable(host->dbclk)) + dev_dbg(mmc_dev(host->mmc), + "Enabling debounce clk failed\n"); + + omap_mmc_restore_ctx(host); + omap_hsmmc_init(host); + mmc_power_restore_host(host->mmc); + + host->dpm_state = ENABLED; + + dev_dbg(mmc_dev(host->mmc), "OFF -> ENABLED\n"); + + return 0; +} + +/* + * Bring MMC host to ENABLED from any other PM state. + */ +static int omap_mmc_enable(struct mmc_host *mmc) +{ + struct mmc_omap_host *host = mmc_priv(mmc); + + switch (host->dpm_state) { + case DISABLED: + return omap_mmc_disabled_to_enabled(host); + case OFF: + return omap_mmc_off_to_enabled(host); + default: + dev_dbg(mmc_dev(host->mmc), "UNKNOWN state\n"); + return -EINVAL; + } +} + +/* + * Bring MMC host in PM state (one level deeper). + */ +static int omap_mmc_disable(struct mmc_host *mmc, int lazy) +{ + struct mmc_omap_host *host = mmc_priv(mmc); + + switch (host->dpm_state) { + case ENABLED: { + int delay; + + delay = omap_mmc_enabled_to_disabled(host); + if (lazy || delay < 0) + return delay; + return 0; + } + case DISABLED: + return omap_mmc_disabled_to_off(host); + default: + dev_dbg(mmc_dev(host->mmc), "UNKNOWN state\n"); + return -EINVAL; + } +} + +static int omap_mmc_enable_fclk(struct mmc_host *mmc) +{ + struct mmc_omap_host *host = mmc_priv(mmc); + int err; + + err = clk_enable(host->fclk); + if (err) + return err; + dev_dbg(mmc_dev(host->mmc), "mmc_fclk: enabled\n"); + omap_mmc_restore_ctx(host); + return 0; +} + +static int omap_mmc_disable_fclk(struct mmc_host *mmc, int lazy) +{ + struct mmc_omap_host *host = mmc_priv(mmc); + + omap_mmc_save_ctx(host); + clk_disable(host->fclk); + dev_dbg(mmc_dev(host->mmc), "mmc_fclk: disabled\n"); + return 0; +} + +static const struct mmc_host_ops mmc_omap_ops = { + .enable = omap_mmc_enable_fclk, + .disable = omap_mmc_disable_fclk, + .request = omap_mmc_request, + .set_ios = omap_mmc_set_ios, + .get_cd = omap_hsmmc_get_cd, + .get_ro = omap_hsmmc_get_ro, + /* NYET -- enable_sdio_irq */ +}; + +static const struct mmc_host_ops mmc_omap_ps_ops = { .enable = omap_mmc_enable, .disable = omap_mmc_disable, .request = omap_mmc_request, @@ -1214,15 +1385,22 @@ static int mmc_regs_show(struct seq_file *s, void *data) seq_printf(s, "mmc%d:\n" " enabled:\t%d\n" + " dpm_state:\t%d\n" " nesting_cnt:\t%d\n" " ctx_loss:\t%d:%d\n" "\nregs:\n", - mmc->index, mmc->enabled ? 1 : 0, mmc->nesting_cnt, + mmc->index, mmc->enabled ? 1 : 0, + host->dpm_state, mmc->nesting_cnt, host->context_loss, context_loss); + if (host->suspended || host->dpm_state == OFF) { + seq_printf(s, "host suspended, can't read registers\n"); + return 0; + } + if (clk_enable(host->fclk) != 0) { seq_printf(s, "can't read the regs\n"); - goto err; + return 0; } seq_printf(s, "SYSCONFIG:\t0x%08x\n", @@ -1241,7 +1419,7 @@ static int mmc_regs_show(struct seq_file *s, void *data) OMAP_HSMMC_READ(host->base, CAPA)); clk_disable(host->fclk); -err: + return 0; } @@ -1323,7 +1501,11 @@ static int __init omap_mmc_probe(struct platform_device *pdev) platform_set_drvdata(pdev, host); INIT_WORK(&host->mmc_carddetect_work, mmc_omap_detect); - mmc->ops = &mmc_omap_ops; + if (pdata->slots[host->slot_id].power_saving) + mmc->ops = &mmc_omap_ps_ops; + else + mmc->ops = &mmc_omap_ops; + mmc->f_min = 400000; mmc->f_max = 52000000; @@ -1346,7 +1528,10 @@ static int __init omap_mmc_probe(struct platform_device *pdev) omap_mmc_save_ctx(host); mmc->caps |= MMC_CAP_DISABLE; - mmc_set_disable_delay(mmc, 100); + mmc_set_disable_delay(mmc, OMAP_MMC_DISABLED_TIMEOUT); + /* we start off in DISABLED state */ + host->dpm_state = DISABLED; + if (mmc_host_enable(host->mmc) != 0) { clk_put(host->iclk); clk_put(host->fclk); -- cgit v1.2.2