mmc: SDHC 3.0: support 10-bit divided clock mode

Signed-off-by: Zhangfei Gao <zgao6@marvell.com>
Cc: Michał Mirosław <mirqus@gmail.com>
Cc: David Vrabel <david.vrabel@csr.com>
Reviewed-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
This commit is contained in:
Zhangfei Gao 2010-08-06 07:10:01 +08:00 committed by Chris Ball
parent 0957c3339e
commit 85105c53b0
2 changed files with 25 additions and 5 deletions

View file

@ -1001,13 +1001,28 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
if (clock == 0)
goto out;
for (div = 1;div < 256;div *= 2) {
if ((host->max_clk / div) <= clock)
break;
if (host->version >= SDHCI_SPEC_300) {
/* Version 3.00 divisors must be a multiple of 2. */
if (host->max_clk <= clock)
div = 1;
else {
for (div = 2; div < 2046; div += 2) {
if ((host->max_clk / div) <= clock)
break;
}
}
} else {
/* Version 2.00 divisors must be a power of 2. */
for (div = 1; div < 256; div *= 2) {
if ((host->max_clk / div) <= clock)
break;
}
}
div >>= 1;
clk = div << SDHCI_DIVIDER_SHIFT;
clk = (div & SDHCI_DIV_MASK) << SDHCI_DIVIDER_SHIFT;
clk |= ((div & SDHCI_DIV_HI_MASK) >> SDHCI_DIV_MASK_LEN)
<< SDHCI_DIVIDER_HI_SHIFT;
clk |= SDHCI_CLOCK_INT_EN;
sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
@ -1708,7 +1723,7 @@ int sdhci_add_host(struct sdhci_host *host)
host->version = sdhci_readw(host, SDHCI_HOST_VERSION);
host->version = (host->version & SDHCI_SPEC_VER_MASK)
>> SDHCI_SPEC_VER_SHIFT;
if (host->version > SDHCI_SPEC_200) {
if (host->version > SDHCI_SPEC_300) {
printk(KERN_ERR "%s: Unknown controller version (%d). "
"You may experience problems.\n", mmc_hostname(mmc),
host->version);

View file

@ -86,6 +86,10 @@
#define SDHCI_CLOCK_CONTROL 0x2C
#define SDHCI_DIVIDER_SHIFT 8
#define SDHCI_DIVIDER_HI_SHIFT 6
#define SDHCI_DIV_MASK 0xFF
#define SDHCI_DIV_MASK_LEN 8
#define SDHCI_DIV_HI_MASK 0x300
#define SDHCI_CLOCK_CARD_EN 0x0004
#define SDHCI_CLOCK_INT_STABLE 0x0002
#define SDHCI_CLOCK_INT_EN 0x0001
@ -178,6 +182,7 @@
#define SDHCI_SPEC_VER_SHIFT 0
#define SDHCI_SPEC_100 0
#define SDHCI_SPEC_200 1
#define SDHCI_SPEC_300 2
struct sdhci_ops;