From a9e58f25734e153b8c6516d904e2398fb8b0b23d Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Wed, 29 Jul 2009 15:04:16 -0700 Subject: sdhci: get rid of "frequency too high" flood when using eSDHC Since commit 8dfd0374be84793360db7fff2e635d2cd3bbcb21 ("MMC core: limit minimum initialization frequency to 400kHz") MMC core checks for minimum frequency, and that causes following messages flood when using eSDHC controllers: ... mmc0: Minimum clock frequency too high for identification mode mmc0: Minimum clock frequency too high for identification mode ... The warnings are legitimate, since if we'd use 133 MHz clocks for standard SDHCI controllers, we'd not able to scale frequency down to 400 kHz. But eSDHC controllers have a non-standard SD clock management, so we can divide clock by 256 * 16, not just 256. This patch introduces get_min_clock() callback for sdhci core and implements it for sdhci-of driver, and thus fixes the issue. Signed-off-by: Anton Vorontsov Cc: Matt Fleming Cc: Ian Molton Cc: "Roberto A. Foglietta" Cc: Pierre Ossman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/mmc/host/sdhci-of.c | 8 ++++++++ drivers/mmc/host/sdhci.c | 5 ++++- drivers/mmc/host/sdhci.h | 1 + 3 files changed, 13 insertions(+), 1 deletion(-) (limited to 'drivers/mmc/host') diff --git a/drivers/mmc/host/sdhci-of.c b/drivers/mmc/host/sdhci-of.c index d79fa55c3b8..908844327db 100644 --- a/drivers/mmc/host/sdhci-of.c +++ b/drivers/mmc/host/sdhci-of.c @@ -158,6 +158,13 @@ static unsigned int esdhc_get_max_clock(struct sdhci_host *host) return of_host->clock; } +static unsigned int esdhc_get_min_clock(struct sdhci_host *host) +{ + struct sdhci_of_host *of_host = sdhci_priv(host); + + return of_host->clock / 256 / 16; +} + static unsigned int esdhc_get_timeout_clock(struct sdhci_host *host) { struct sdhci_of_host *of_host = sdhci_priv(host); @@ -184,6 +191,7 @@ static struct sdhci_of_data sdhci_esdhc = { .set_clock = esdhc_set_clock, .enable_dma = esdhc_enable_dma, .get_max_clock = esdhc_get_max_clock, + .get_min_clock = esdhc_get_min_clock, .get_timeout_clock = esdhc_get_timeout_clock, }, }; diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 6779b4ecab1..62041c7e924 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1766,7 +1766,10 @@ int sdhci_add_host(struct sdhci_host *host) * Set host parameters. */ mmc->ops = &sdhci_ops; - mmc->f_min = host->max_clk / 256; + if (host->ops->get_min_clock) + mmc->f_min = host->ops->get_min_clock(host); + else + mmc->f_min = host->max_clk / 256; mmc->f_max = host->max_clk; mmc->caps = MMC_CAP_SDIO_IRQ; diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h index 831ddf7dcb4..c77e9ff3022 100644 --- a/drivers/mmc/host/sdhci.h +++ b/drivers/mmc/host/sdhci.h @@ -302,6 +302,7 @@ struct sdhci_ops { int (*enable_dma)(struct sdhci_host *host); unsigned int (*get_max_clock)(struct sdhci_host *host); + unsigned int (*get_min_clock)(struct sdhci_host *host); unsigned int (*get_timeout_clock)(struct sdhci_host *host); }; -- cgit v1.2.3-70-g09d2