mmc: sdhci high speed support

The SDHCI spec implies that is is incorrect to set a clock
frequency above 25 MHz without setting the high speed bit.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This commit is contained in:
Pierre Ossman 2006-11-08 23:06:35 +01:00
parent 7ccd266e67
commit 077df88483
2 changed files with 17 additions and 0 deletions

View file

@ -616,6 +616,7 @@ static void sdhci_finish_command(struct sdhci_host *host)
static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
{
int div;
u8 ctrl;
u16 clk;
unsigned long timeout;
@ -624,6 +625,13 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
writew(0, host->ioaddr + SDHCI_CLOCK_CONTROL);
ctrl = readb(host->ioaddr + SDHCI_HOST_CONTROL);
if (clock > 25000000)
ctrl |= SDHCI_CTRL_HISPD;
else
ctrl &= ~SDHCI_CTRL_HISPD;
writeb(ctrl, host->ioaddr + SDHCI_HOST_CONTROL);
if (clock == 0)
goto out;
@ -1291,6 +1299,13 @@ static int __devinit sdhci_probe_slot(struct pci_dev *pdev, int slot)
else if (caps & SDHCI_CAN_VDD_180)
mmc->ocr_avail |= MMC_VDD_17_18|MMC_VDD_18_19;
if ((host->max_clk > 25000000) && !(caps & SDHCI_CAN_DO_HISPD)) {
printk(KERN_ERR "%s: Controller reports > 25 MHz base clock,"
" but no high speed support.\n",
host->slot_descr);
mmc->f_max = 25000000;
}
if (mmc->ocr_avail == 0) {
printk(KERN_ERR "%s: Hardware doesn't report any "
"support voltages.\n", host->slot_descr);

View file

@ -71,6 +71,7 @@
#define SDHCI_HOST_CONTROL 0x28
#define SDHCI_CTRL_LED 0x01
#define SDHCI_CTRL_4BITBUS 0x02
#define SDHCI_CTRL_HISPD 0x04
#define SDHCI_POWER_CONTROL 0x29
#define SDHCI_POWER_ON 0x01
@ -138,6 +139,7 @@
#define SDHCI_CLOCK_BASE_SHIFT 8
#define SDHCI_MAX_BLOCK_MASK 0x00030000
#define SDHCI_MAX_BLOCK_SHIFT 16
#define SDHCI_CAN_DO_HISPD 0x00200000
#define SDHCI_CAN_DO_DMA 0x00400000
#define SDHCI_CAN_VDD_330 0x01000000
#define SDHCI_CAN_VDD_300 0x02000000