Some nitpicks.
On 10/24/2012 10:20 AM, Stephen Warren 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-3.2.27
No s-o-b tags were present in either location.
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().
- Simplified and commented twoticks_delay calculation.
- checkpatch fixes.
Cc: Oleksandr Tymoshenkogonzo@bluezbox.com Signed-off-by: Stephen Warrenswarren@wwwdotorg.org
This series is based on the previous bcm2835 patches I sent, to add the mbox and video drivers. Patch 1 should be independant, but patch 2 depends on those other patches.
arch/arm/include/asm/arch-bcm2835/sdhci.h | 24 ++++ drivers/mmc/Makefile | 1 + drivers/mmc/bcm2835_sdhci.c | 172 +++++++++++++++++++++++++++++ 3 files changed, 197 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..1d623c0 --- /dev/null +++ b/drivers/mmc/bcm2835_sdhci.c @@ -0,0 +1,172 @@ +/*
- 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-3.2.27
- 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;
- /*
* The Arasan has a bugette whereby it may lose the content of* successive writes to registers that are within two SD-card clock* cycles of each other (a clock domain crossing problem).* It seems, however, that the data register does not have this problem.* (Which is just as well - otherwise we'd have to nobble the DMA engine* too)*/- while (get_timer(last_write)< twoticks_delay)
;- writel(val, host->ioaddr + reg);
- last_write = get_timer(0);
+}
+static inline u32 bcm2835_sdhci_raw_readl(struct sdhci_host *host, int reg) +{
- return readl(host->ioaddr + reg);
+}
+static void bcm2835_sdhci_writel(struct sdhci_host *host, u32 val, int reg) +{
- bcm2835_sdhci_raw_writel(host, val, reg);
+}
+static void bcm2835_sdhci_writew(struct sdhci_host *host, u16 val, int reg) +{
- static u32 shadow;
- u32 p = reg == SDHCI_COMMAND ? shadow :
bcm2835_sdhci_raw_readl(host, reg& ~3);- u32 s = reg<< 3& 0x18;
- u32 l = val<< s;
- u32 m = 0xffff<< s;
- if (reg == SDHCI_TRANSFER_MODE)
shadow = (p& ~m) | l;- else
bcm2835_sdhci_raw_writel(host, (p& ~m) | l, reg& ~3);+}
+static void bcm2835_sdhci_writeb(struct sdhci_host *host, u8 val, int reg) +{
- u32 p = bcm2835_sdhci_raw_readl(host, reg& ~3);
- u32 s = reg<< 3& 0x18;
- u32 l = val<< s;
- u32 m = 0xff<< s;
- bcm2835_sdhci_raw_writel(host, (p& ~m) | l, reg& ~3);
+}
+static u32 bcm2835_sdhci_readl(struct sdhci_host *host, int reg) +{
- u32 val = bcm2835_sdhci_raw_readl(host, reg);
- return val;
+}
+static u16 bcm2835_sdhci_readw(struct sdhci_host *host, int reg) +{
- u32 val = bcm2835_sdhci_raw_readl(host, (reg& ~3));
- val = val>> (reg<< 3& 0x18)& 0xffff;
- return (u16)val;
+}
+static u8 bcm2835_sdhci_readb(struct sdhci_host *host, int reg) +{
- u32 val = bcm2835_sdhci_raw_readl(host, (reg& ~3));
- val = val>> (reg<< 3& 0x18)& 0xff;
- return (u8)val;
+}
Can the above used magics be made as macros?
~Vikram