From e83b7a8acc420923cbe8a30901d9eb60677f54fb Mon Sep 17 00:00:00 2001 From: Guennadi Liakhovetski Date: Thu, 6 Jun 2013 16:35:44 +0200 Subject: [PATCH] mmc: tmio: fix unbalanced power-on calls with clock-gating enabled With MMC clock gating enabled the MMC core currently calls MMC host driver's .set_ios() method with .power_mode == MMC_POWER_ON and the clock value set either to 0 or to the target rate. The tmio MMC driver then wrongly translates the latter calls to card slot power-on requests, even when the slot already was on. This patch fixes the driver to avoid needlessly incrementing power-supplying regulator's use count. Signed-off-by: Guennadi Liakhovetski Tested-by: Laurent Pinchart Signed-off-by: Chris Ball --- drivers/mmc/host/tmio_mmc.h | 20 ++++++++++++++++++-- drivers/mmc/host/tmio_mmc_pio.c | 27 +++++++++++++++++---------- 2 files changed, 35 insertions(+), 12 deletions(-) diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h index 759d8f4..86fd21e 100644 --- a/drivers/mmc/host/tmio_mmc.h +++ b/drivers/mmc/host/tmio_mmc.h @@ -40,6 +40,22 @@ struct tmio_mmc_data; +/* + * We differentiate between the following 3 power states: + * 1. card slot powered off, controller stopped. This is used, when either there + * is no card in the slot, or the card really has to be powered down. + * 2. card slot powered on, controller stopped. This is used, when a card is in + * the slot, but no activity is currently taking place. This is a power- + * saving mode with card-state preserved. This state can be entered, e.g. + * when MMC clock-gating is used. + * 3. card slot powered on, controller running. This is the actual active state. + */ +enum tmio_mmc_power { + TMIO_MMC_OFF_STOP, /* card power off, controller stopped */ + TMIO_MMC_ON_STOP, /* card power on, controller stopped */ + TMIO_MMC_ON_RUN, /* card power on, controller running */ +}; + struct tmio_mmc_host { void __iomem *ctl; unsigned long bus_shift; @@ -48,8 +64,8 @@ struct tmio_mmc_host { struct mmc_data *data; struct mmc_host *mmc; - /* Controller power state */ - bool power; + /* Controller and card power state */ + enum tmio_mmc_power power; /* Callbacks for clock / power control */ void (*set_pwr)(struct platform_device *host, int state); diff --git a/drivers/mmc/host/tmio_mmc_pio.c b/drivers/mmc/host/tmio_mmc_pio.c index 435cc4d..67d9642 100644 --- a/drivers/mmc/host/tmio_mmc_pio.c +++ b/drivers/mmc/host/tmio_mmc_pio.c @@ -859,7 +859,7 @@ static void tmio_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) * is kept positive, so no suspending actually takes place. */ if (ios->power_mode == MMC_POWER_ON && ios->clock) { - if (!host->power) { + if (host->power != TMIO_MMC_ON_RUN) { tmio_mmc_clk_update(mmc); pm_runtime_get_sync(dev); if (host->resuming) { @@ -868,27 +868,34 @@ static void tmio_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) } } tmio_mmc_set_clock(host, ios->clock); - if (!host->power) { + if (host->power == TMIO_MMC_OFF_STOP) /* power up SD card and the bus */ tmio_mmc_power_on(host, ios->vdd); - host->power = true; - } + host->power = TMIO_MMC_ON_RUN; /* start bus clock */ tmio_mmc_clk_start(host); } else if (ios->power_mode != MMC_POWER_UP) { - if (host->power) { - struct tmio_mmc_data *pdata = host->pdata; - if (ios->power_mode == MMC_POWER_OFF) + struct tmio_mmc_data *pdata = host->pdata; + unsigned int old_power = host->power; + + if (old_power != TMIO_MMC_OFF_STOP) { + if (ios->power_mode == MMC_POWER_OFF) { tmio_mmc_power_off(host); + host->power = TMIO_MMC_OFF_STOP; + } else { + host->power = TMIO_MMC_ON_STOP; + } + } + + if (old_power == TMIO_MMC_ON_RUN) { tmio_mmc_clk_stop(host); - host->power = false; pm_runtime_put(dev); if (pdata->clk_disable) pdata->clk_disable(host->pdev); } } - if (host->power) { + if (host->power != TMIO_MMC_OFF_STOP) { switch (ios->bus_width) { case MMC_BUS_WIDTH_1: sd_ctrl_write16(host, CTL_SD_MEM_CARD_OPT, 0x80e0); @@ -1029,7 +1036,7 @@ int tmio_mmc_host_probe(struct tmio_mmc_host **host, mmc->caps & MMC_CAP_NONREMOVABLE || mmc->slot.cd_irq >= 0); - _host->power = false; + _host->power = TMIO_MMC_OFF_STOP; pm_runtime_enable(&pdev->dev); ret = pm_runtime_resume(&pdev->dev); if (ret < 0) -- 2.7.4