From: jiri.prchal@aksignal.cz (Prchal Jiří)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] mmc: at91: fix bus speed
Date: Wed, 20 Jun 2012 10:15:04 +0200 [thread overview]
Message-ID: <4FE18688.4000700@aksignal.cz> (raw)
This patch change minimum and maximum clock speed because some noname cards doesn't work during init even at 375kHz and
new cards (SD v. 3.0) can run at 50 or 100 MHz.
Also aded clkdiv register overrun fix when setting low speeds.
Signed-off-by: Jiri Prchal <jiri.prchal@aksignal.cz>
---
--- linux/linux-3.5-rc3/drivers/mmc/host/at91_mci.c.orig 2012-06-17 02:25:17.000000000 +0200
+++ linux/linux-3.5-rc3/drivers/mmc/host/at91_mci.c 2012-06-18 11:01:49.751415984 +0200
@@ -724,6 +724,10 @@ static void at91_mci_set_ios(struct mmc_
else
clkdiv = (at91_master_clock / ios->clock) / 2;
+ /* set maximum divider */
+ if (clkdiv > 255)
+ clkdiv = 255;
+
pr_debug("clkdiv = %d. mcck = %ld\n", clkdiv,
at91_master_clock / (2 * (clkdiv + 1)));
}
@@ -948,8 +952,8 @@ static int __init at91_mci_probe(struct
}
mmc->ops = &at91_mci_ops;
- mmc->f_min = 375000;
- mmc->f_max = 25000000;
+ mmc->f_min = 200000; /* not all cards can run at 375kHz */
+ mmc->f_max = 100000000; /* new cards can run at 100MHz */
mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
mmc->caps = 0;
next reply other threads:[~2012-06-20 8:15 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-20 8:15 Prchal Jiří [this message]
2012-06-20 8:49 ` [PATCH] mmc: at91: fix bus speed ludovic.desroches
2012-06-20 9:13 ` Fwd: " ludovic.desroches
2012-06-21 7:56 ` Prchal Jiří
2012-06-21 8:23 ` ludovic.desroches
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