On Mon, Nov 26, 2012 at 10:38 PM, Stephen Warren <swar...@wwwdotorg.org>wrote:
> 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 <aflem...@gmail.com> > Signed-off-by: Oleksandr Tymoshenko <go...@bluezbox.com> > Signed-off-by: Stephen Warren <swar...@wwwdotorg.org> > --- > v4: > * Merged with video patch series due to dependencies in rpi_b.h. > * Rebased onto latest u-boot-arm/master; no real changes. > v3: No such version was posted. > v2: > * Use more descriptive variable names and calculations in IO accessors. > * Add Oleksandr's S-o-b. > * Rewrite commit description to note that the Linux code this was derived > from was S-o-b Dom Cobley. > --- > arch/arm/include/asm/arch-bcm2835/sdhci.h | 24 ++++ > drivers/mmc/Makefile | 1 + > drivers/mmc/bcm2835_sdhci.c | 177 > +++++++++++++++++++++++++++++ > 3 files changed, 202 insertions(+) > create mode 100644 arch/arm/include/asm/arch-bcm2835/sdhci.h > create mode 100644 drivers/mmc/bcm2835_sdhci.c > > diff --git a/arch/arm/include/asm/arch-bcm2835/sdhci.h > b/arch/arm/include/asm/arch-bcm2835/sdhci.h > new file mode 100644 > index 0000000..a4f867b > --- /dev/null > +++ b/arch/arm/include/asm/arch-bcm2835/sdhci.h > @@ -0,0 +1,24 @@ > +/* > + * (C) Copyright 2012 Stephen Warren > + * > + * See file CREDITS for list of people who contributed to this > + * project. > + * > + * This program is free software; you can redistribute it and/or > + * modify it under the terms of the GNU General Public License > + * version 2 as published by the Free Software Foundation. > + * > + * This program is distributed in the hope that it will be useful, but > + * WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > + > +#ifndef _BCM2835_SDHCI_H_ > +#define _BCM2835_SDHCI_H_ > + > +#define BCM2835_SDHCI_BASE 0x20300000 > + > +int bcm2835_sdhci_init(u32 regbase, u32 emmc_freq); > + > +#endif > diff --git a/drivers/mmc/Makefile b/drivers/mmc/Makefile > index a1dd730..6be36f2 100644 > --- a/drivers/mmc/Makefile > +++ b/drivers/mmc/Makefile > @@ -43,6 +43,7 @@ COBJS-$(CONFIG_MXS_MMC) += mxsmmc.o > COBJS-$(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 > diff --git a/drivers/mmc/bcm2835_sdhci.c b/drivers/mmc/bcm2835_sdhci.c > new file mode 100644 > index 0000000..8f2137e > --- /dev/null > +++ b/drivers/mmc/bcm2835_sdhci.c > @@ -0,0 +1,177 @@ > +/* > + * This code was extracted from: > + * git://github.com/gonzoua/u-boot-pi.git master > + * and hence presumably (C) 2012 Oleksandr Tymoshenko > + * > + * Tweaks for U-Boot upstreaming > + * (C) 2012 Stephen Warren > + * > + * Portions (e.g. read/write macros, concepts for back-to-back register > write > + * timing workarounds) obviously extracted from the Linux kernel at: > + * https://github.com/raspberrypi/linux.git rpi-3.6.y > + * > + * The Linux kernel code has the following (c) and license, which is hence > + * propagated to Oleksandr's tree and here: > + * > + * Support for SDHCI device on 2835 > + * Based on sdhci-bcm2708.c (c) 2010 Broadcom > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program; if not, write to the Free Software > + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. > + */ > + > +/* Supports: > + * SDHCI platform device - Arasan SD controller in BCM2708 > + * > + * Inspired by sdhci-pci.c, by Pierre Ossman > + */ > + > +#include <common.h> > +#include <malloc.h> > +#include <sdhci.h> > + > +/* 400KHz is max freq for card ID etc. Use that as min */ > +#define MIN_FREQ 400000 > + > +static uint twoticks_delay; > + > +static inline void bcm2835_sdhci_raw_writel(struct sdhci_host *host, u32 > val, > + int reg) > +{ > + static ulong last_write; > I don't suppose there's any way you could do this without a global variable? If someone ever plops two of these things down on a system, we're gonna have weird race condition possibilities. Perhaps an array, accessed via host->index? Andy
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