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[MMC] sdhci: proper timeout handling

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Use the give timeout clock and calculate a proper timeout instead of using the
maximum at all times.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Pierre Ossman 2006-06-30 02:22:25 -07:00 committed by Russell King
parent e16514d8d8
commit 1c8cde92fa
2 changed files with 48 additions and 3 deletions
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47
drivers/mmc/sdhci.c
View File

@ -128,9 +128,6 @@ static void sdhci_init(struct sdhci_host *host)
writel(intmask, host->ioaddr + SDHCI_INT_ENABLE);
writel(intmask, host->ioaddr + SDHCI_SIGNAL_ENABLE);
/* This is unknown magic. */
writeb(0xE, host->ioaddr + SDHCI_TIMEOUT_CONTROL);
}
static void sdhci_activate_led(struct sdhci_host *host)
@ -274,6 +271,8 @@ static void sdhci_transfer_pio(struct sdhci_host *host)
static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_data *data)
{
u16 mode;
u8 count;
unsigned target_timeout, current_timeout;
WARN_ON(host->data);
@ -287,6 +286,37 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_data *data)
DBG("tsac %d ms nsac %d clk\n",
data->timeout_ns / 1000000, data->timeout_clks);
/* timeout in us */
target_timeout = data->timeout_ns / 1000 +
data->timeout_clks / host->clock;
/*
* Figure out needed cycles.
* We do this in steps in order to fit inside a 32 bit int.
* The first step is the minimum timeout, which will have a
* minimum resolution of 6 bits:
* (1) 2^13*1000 > 2^22,
* (2) host->timeout_clk < 2^16
* =>
* (1) / (2) > 2^6
*/
count = 0;
current_timeout = (1 << 13) * 1000 / host->timeout_clk;
while (current_timeout < target_timeout) {
count++;
current_timeout <<= 1;
if (count >= 0xF)
break;
}
if (count >= 0xF) {
printk(KERN_WARNING "%s: Too large timeout requested!\n",
mmc_hostname(host->mmc));
count = 0xE;
}
writeb(count, host->ioaddr + SDHCI_TIMEOUT_CONTROL);
mode = SDHCI_TRNS_BLK_CNT_EN;
if (data->blocks > 1)
mode |= SDHCI_TRNS_MULTI;
@ -1096,6 +1126,17 @@ static int __devinit sdhci_probe_slot(struct pci_dev *pdev, int slot)
}
host->max_clk *= 1000000;
host->timeout_clk =
(caps & SDHCI_TIMEOUT_CLK_MASK) >> SDHCI_TIMEOUT_CLK_SHIFT;
if (host->timeout_clk == 0) {
printk(KERN_ERR "%s: Hardware doesn't specify timeout clock "
"frequency.\n", host->slot_descr);
ret = -ENODEV;
goto unmap;
}
if (caps & SDHCI_TIMEOUT_CLK_UNIT)
host->timeout_clk *= 1000;
/*
* Set host parameters.
*/

4
drivers/mmc/sdhci.h
View File

@ -125,6 +125,9 @@
/* 3E-3F reserved */
#define SDHCI_CAPABILITIES 0x40
#define SDHCI_TIMEOUT_CLK_MASK 0x0000003F
#define SDHCI_TIMEOUT_CLK_SHIFT 0
#define SDHCI_TIMEOUT_CLK_UNIT 0x00000080
#define SDHCI_CLOCK_BASE_MASK 0x00003F00
#define SDHCI_CLOCK_BASE_SHIFT 8
#define SDHCI_CAN_DO_DMA 0x00400000
@ -156,6 +159,7 @@ struct sdhci_host {
#define SDHCI_USE_DMA (1<<0)
unsigned int max_clk; /* Max possible freq (MHz) */
unsigned int timeout_clk; /* Timeout freq (KHz) */
unsigned int clock; /* Current clock (MHz) */
unsigned short power; /* Current voltage */