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author | Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> | 2012-11-13 21:07:21 +0100 |
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committer | Sascha Hauer <s.hauer@pengutronix.de> | 2012-11-14 21:09:41 +0100 |
commit | 6d0d1392f4db942390d0fe18ca9c98f7c53f3c4e (patch) | |
tree | f5af840ac15660f0e80014570310702b48aeb96a /drivers/mci/mci_spi.c | |
parent | 0738b3c6fe2425e03f3c858b3809dd584b826c8f (diff) | |
download | barebox-6d0d1392f4db942390d0fe18ca9c98f7c53f3c4e.tar.gz barebox-6d0d1392f4db942390d0fe18ca9c98f7c53f3c4e.tar.xz |
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>
Diffstat (limited to 'drivers/mci/mci_spi.c')
-rw-r--r-- | drivers/mci/mci_spi.c | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/drivers/mci/mci_spi.c b/drivers/mci/mci_spi.c index 08939bea58..679a0e1e02 100644 --- a/drivers/mci/mci_spi.c +++ b/drivers/mci/mci_spi.c @@ -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; |