sysmo-bts
/
barebox
9
0
Fork 0
Code Releases Activity

mci_spi: add clock frequency change support 

setup the spi master correctly

provide f_min and f_max

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This commit is contained in:
Jean-Christophe PLAGNIOL-VILLARD 2012-11-13 21:07:21 +01:00 committed by Sascha Hauer
parent 0738b3c6fe
commit 6d0d1392f4
1 changed files with 28 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
drivers/mci/mci_spi.c
View File

@ -318,7 +318,15 @@ static void mmc_spi_set_ios(struct mci_host *mci, struct mci_ios *ios)
{
struct mmc_spi_host *host = to_spi_host(mci);
spi_setup(host->spi);
if (host->spi->max_speed_hz != ios->clock && ios->clock != 0) {
int status;
host->spi->max_speed_hz = ios->clock;
status = spi_setup(host->spi);
dev_dbg(&host->spi->dev,
"mmc_spi: clock to %d Hz, %d\n",
host->spi->max_speed_hz, status);
}
}
static int mmc_spi_init(struct mci_host *mci, struct device_d *mci_dev)
@ -384,6 +392,25 @@ static int spi_mci_probe(struct device_d *dev)
spi->mode = SPI_MODE_0;
spi->bits_per_word = 8;
status = spi_setup(spi);
if (status < 0) {
dev_dbg(&spi->dev, "needs SPI mode %02x, %d KHz; %d\n",
spi->mode, spi->max_speed_hz / 1000,
status);
return status;
}
/* SPI doesn't need the lowspeed device identification thing for
* MMC or SD cards, since it never comes up in open drain mode.
* That's good; some SPI masters can't handle very low speeds!
*
* However, low speed SDIO cards need not handle over 400 KHz;
* that's the only reason not to use a few MHz for f_min (until
* the upper layer reads the target frequency from the CSD).
*/
host->mci.f_min = 400000;
host->mci.f_max = spi->max_speed_hz;
host->dev = dev;
host->spi = spi;
dev->priv = host;