From a6609267107ecc5598b79aa353036c1f57e7257e Mon Sep 17 00:00:00 2001 From: Guennadi Liakhovetski Date: Thu, 19 Apr 2012 18:02:50 +0200 Subject: mmc: sh_mmcif: re-read the clock frequency every time it is turned on With aggressive clock gating the clock can be disabled during interface inactivity. During this time its frequency can be changed by another its user. Therefore when the interface is activated again and the clock is re-enabled, its frequency has to be re-read. Signed-off-by: Guennadi Liakhovetski Reviewed-by: Simon Horman Signed-off-by: Chris Ball --- drivers/mmc/host/sh_mmcif.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) (limited to 'drivers/mmc') diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c index 6a93b046685..3ffb92fc084 100644 --- a/drivers/mmc/host/sh_mmcif.c +++ b/drivers/mmc/host/sh_mmcif.c @@ -910,6 +910,19 @@ static void sh_mmcif_request(struct mmc_host *mmc, struct mmc_request *mrq) sh_mmcif_start_cmd(host, mrq); } +static int sh_mmcif_clk_update(struct sh_mmcif_host *host) +{ + int ret = clk_enable(host->hclk); + + if (!ret) { + host->clk = clk_get_rate(host->hclk); + host->mmc->f_max = host->clk / 2; + host->mmc->f_min = host->clk / 512; + } + + return ret; +} + static void sh_mmcif_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) { struct sh_mmcif_host *host = mmc_priv(mmc); @@ -955,7 +968,7 @@ static void sh_mmcif_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) if (!host->power) { if (p->set_pwr) p->set_pwr(host->pd, ios->power_mode); - clk_enable(host->hclk); + sh_mmcif_clk_update(host); pm_runtime_get_sync(&host->pd->dev); host->power = true; sh_mmcif_sync_reset(host); @@ -1308,10 +1321,9 @@ static int __devinit sh_mmcif_probe(struct platform_device *pdev) dev_err(&pdev->dev, "cannot get clock \"%s\": %d\n", clk_name, ret); goto eclkget; } - clk_enable(host->hclk); - host->clk = clk_get_rate(host->hclk); - mmc->f_max = host->clk / 2; - mmc->f_min = host->clk / 512; + ret = sh_mmcif_clk_update(host); + if (ret < 0) + goto eclkupdate; ret = pm_runtime_resume(&pdev->dev); if (ret < 0) @@ -1353,6 +1365,7 @@ ereqirq0: pm_runtime_suspend(&pdev->dev); eresume: clk_disable(host->hclk); +eclkupdate: clk_put(host->hclk); eclkget: pm_runtime_disable(&pdev->dev); -- cgit v1.2.3