mmc: add bcm2835 driver
This adds a simple driver for the BCM2835's SD controller.
Workarounds are implemented for:
* Register writes can't be too close to each-other in time, or they will
be lost.
* Register accesses must all be 32-bit, so implement custom accessors.
This code was extracted from:
git://github.com/gonzoua/u-boot-pi.git master
which was created by Oleksandr Tymoshenko.
Portions of the code there were obviously based on the Linux kernel at:
git://github.com/raspberrypi/linux.git rpi-3.6.y
commit f5b930b "Main bcm2708 linux port" signed-off-by Dom Cobley.
swarren changed the following for upstream:
* Removed hack udelay()s in bcm2835_sdhci_raw_writel(); setting
SDHCI_QUIRK_WAIT_SEND_CMD appears to solve the issues.
* Remove register logging from read*/write* functions.
* Sort out confusion with min/max_freq values passed to add_sdhci().
* Use more descriptive variable names and calculations in IO accessors.
* Simplified and commented twoticks_delay calculation.
* checkpatch fixes.
Cc: Andy Fleming <afleming@gmail.com>
Signed-off-by: Oleksandr Tymoshenko <gonzo@bluezbox.com>
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: Andy Fleming <afleming@gmail.com>
diff --git a/drivers/mmc/Makefile b/drivers/mmc/Makefile
index 65791aa..1d6faa2 100644
--- a/drivers/mmc/Makefile
+++ b/drivers/mmc/Makefile
@@ -43,6 +43,7 @@
COBJS-$(CONFIG_OMAP_HSMMC) += omap_hsmmc.o
COBJS-$(CONFIG_PXA_MMC_GENERIC) += pxa_mmc_gen.o
COBJS-$(CONFIG_SDHCI) += sdhci.o
+COBJS-$(CONFIG_BCM2835_SDHCI) += bcm2835_sdhci.o
COBJS-$(CONFIG_S5P_SDHCI) += s5p_sdhci.o
COBJS-$(CONFIG_SH_MMCIF) += sh_mmcif.o
COBJS-$(CONFIG_TEGRA_MMC) += tegra_mmc.o