[U-Boot] [PATCH V2 1/2] mmc: add bcm2835 driver

[U-Boot] [PATCH V2 1/2] mmc: add bcm2835 driver

[Stephen Warren]

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.

Signed-off-by: Oleksandr Tymoshenko <gonzo@bluezbox.com>
Signed-off-by: Stephen Warren <swarren@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.

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;
+
+	/*
+	 * 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 oldval = (reg == SDHCI_COMMAND) ? shadow :
+		bcm2835_sdhci_raw_readl(host, reg & ~3);
+	u32 word_num = (reg >> 1) & 1;
+	u32 word_shift = word_num * 16;
+	u32 mask = 0xffff << word_shift;
+	u32 newval = (oldval & ~mask) | (val << word_shift);
+
+	if (reg == SDHCI_TRANSFER_MODE)
+		shadow = newval;
+	else
+		bcm2835_sdhci_raw_writel(host, newval, reg & ~3);
+}
+
+static void bcm2835_sdhci_writeb(struct sdhci_host *host, u8 val, int reg)
+{
+	u32 oldval = bcm2835_sdhci_raw_readl(host, reg & ~3);
+	u32 byte_num = reg & 3;
+	u32 byte_shift = byte_num * 8;
+	u32 mask = 0xff << byte_shift;
+	u32 newval = (oldval & ~mask) | (val << byte_shift);
+
+	bcm2835_sdhci_raw_writel(host, newval, 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));
+	u32 word_num = (reg >> 1) & 1;
+	u32 word_shift = word_num * 16;
+	u32 word = (val >> word_shift) & 0xffff;
+
+	return word;
+}
+
+static u8 bcm2835_sdhci_readb(struct sdhci_host *host, int reg)
+{
+	u32 val = bcm2835_sdhci_raw_readl(host, (reg & ~3));
+	u32 byte_num = reg & 3;
+	u32 byte_shift = byte_num * 8;
+	u32 byte = (val >> byte_shift) & 0xff;
+
+	return byte;
+}
+
+static const struct sdhci_ops bcm2835_ops = {
+	.write_l = bcm2835_sdhci_writel,
+	.write_w = bcm2835_sdhci_writew,
+	.write_b = bcm2835_sdhci_writeb,
+	.read_l = bcm2835_sdhci_readl,
+	.read_w = bcm2835_sdhci_readw,
+	.read_b = bcm2835_sdhci_readb,
+};
+
+int bcm2835_sdhci_init(u32 regbase, u32 emmc_freq)
+{
+	struct sdhci_host *host = NULL;
+
+	/*
+	 * See the comments in bcm2835_sdhci_raw_writel().
+	 *
+	 * This should probably be dynamically calculated based on the actual
+	 * frequency. However, this is the longest we'll have to wait, and
+	 * doesn't seem to slow access down too much, so the added complexity
+	 * doesn't seem worth it for now.
+	 *
+	 * 1/MIN_FREQ is (max) time per tick of eMMC clock.
+	 * 2/MIN_FREQ is time for two ticks.
+	 * Multiply by 1000000 to get uS per two ticks.
+	 * +1 for hack rounding.
+	 */
+	twoticks_delay = ((2 * 1000000) / MIN_FREQ) + 1;
+
+	host = malloc(sizeof(struct sdhci_host));
+	if (!host) {
+		printf("sdhci_host malloc fail!\n");
+		return 1;
+	}
+
+	host->name = "bcm2835_sdhci";
+	host->ioaddr = (void *)regbase;
+	host->quirks = SDHCI_QUIRK_BROKEN_VOLTAGE | SDHCI_QUIRK_BROKEN_R1B |
+		SDHCI_QUIRK_WAIT_SEND_CMD;
+	host->voltages = MMC_VDD_32_33 | MMC_VDD_33_34 | MMC_VDD_165_195;
+	host->ops = &bcm2835_ops;
+
+	host->version = sdhci_readw(host, SDHCI_HOST_VERSION);
+	add_sdhci(host, emmc_freq, MIN_FREQ);
+
+	return 0;
+}
-- 
1.7.9.5

[U-Boot] [PATCH V2 2/2] ARM: rpi_b: enable SD controller, add related env/cmds

[Stephen Warren]

Enable the SD controller driver for the Raspberry Pi. Enable a number
of useful MMC, partition, and filesystem-related commands. Set up the
environment to provide standard locations for loading a kernel, DTB,
etc. Provide a boot command that loads and executes boot.scr.uimg from
the SD card; this is written considering future extensibilty to USB
storage.

Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
---
 arch/arm/include/asm/arch-bcm2835/mbox.h |   26 ++++++++++++
 board/raspberrypi/rpi_b/rpi_b.c          |   26 ++++++++++++
 include/configs/rpi_b.h                  |   68 ++++++++++++++++++++++++++++--
 3 files changed, 117 insertions(+), 3 deletions(-)

diff --git a/arch/arm/include/asm/arch-bcm2835/mbox.h b/arch/arm/include/asm/arch-bcm2835/mbox.h
index 4752091..b07c4a0 100644
--- a/arch/arm/include/asm/arch-bcm2835/mbox.h
+++ b/arch/arm/include/asm/arch-bcm2835/mbox.h
@@ -144,6 +144,32 @@ struct bcm2835_mbox_tag_get_arm_mem {
 	} body;
 };
 
+#define BCM2835_MBOX_TAG_GET_CLOCK_RATE	0x00030002
+
+#define BCM2835_MBOX_CLOCK_ID_EMMC	1
+#define BCM2835_MBOX_CLOCK_ID_UART	2
+#define BCM2835_MBOX_CLOCK_ID_ARM	3
+#define BCM2835_MBOX_CLOCK_ID_CORE	4
+#define BCM2835_MBOX_CLOCK_ID_V3D	5
+#define BCM2835_MBOX_CLOCK_ID_H264	6
+#define BCM2835_MBOX_CLOCK_ID_ISP	7
+#define BCM2835_MBOX_CLOCK_ID_SDRAM	8
+#define BCM2835_MBOX_CLOCK_ID_PIXEL	9
+#define BCM2835_MBOX_CLOCK_ID_PWM	10
+
+struct bcm2835_mbox_tag_get_clock_rate {
+	struct bcm2835_mbox_tag_hdr tag_hdr;
+	union {
+		struct {
+			u32 clock_id;
+		} req;
+		struct {
+			u32 clock_id;
+			u32 rate_hz;
+		} resp;
+	} body;
+};
+
 #define BCM2835_MBOX_TAG_ALLOCATE_BUFFER	0x00040001
 
 struct bcm2835_mbox_tag_allocate_buffer {
diff --git a/board/raspberrypi/rpi_b/rpi_b.c b/board/raspberrypi/rpi_b/rpi_b.c
index 3c654a1..6b3e095 100644
--- a/board/raspberrypi/rpi_b/rpi_b.c
+++ b/board/raspberrypi/rpi_b/rpi_b.c
@@ -16,6 +16,7 @@
 
 #include <common.h>
 #include <asm/arch/mbox.h>
+#include <asm/arch/sdhci.h>
 #include <asm/global_data.h>
 
 DECLARE_GLOBAL_DATA_PTR;
@@ -26,6 +27,12 @@ struct msg_get_arm_mem {
 	u32 end_tag;
 };
 
+struct msg_get_clock_rate {
+	struct bcm2835_mbox_hdr hdr;
+	struct bcm2835_mbox_tag_get_clock_rate get_clock_rate;
+	u32 end_tag;
+};
+
 int dram_init(void)
 {
 	ALLOC_ALIGN_BUFFER(struct msg_get_arm_mem, msg, 1, 16);
@@ -51,3 +58,22 @@ int board_init(void)
 
 	return 0;
 }
+
+int board_mmc_init(void)
+{
+	ALLOC_ALIGN_BUFFER(struct msg_get_clock_rate, msg_clk, 1, 16);
+	int ret;
+
+	BCM2835_MBOX_INIT_HDR(msg_clk);
+	BCM2835_MBOX_INIT_TAG(&msg_clk->get_clock_rate, GET_CLOCK_RATE);
+	msg_clk->get_clock_rate.body.req.clock_id = BCM2835_MBOX_CLOCK_ID_EMMC;
+
+	ret = bcm2835_mbox_call_prop(BCM2835_MBOX_PROP_CHAN, &msg_clk->hdr);
+	if (ret) {
+		printf("bcm2835: Could not query eMMC clock rate\n");
+		return -1;
+	}
+
+	return bcm2835_sdhci_init(BCM2835_SDHCI_BASE,
+				  msg_clk->get_clock_rate.body.resp.rate_hz);
+}
diff --git a/include/configs/rpi_b.h b/include/configs/rpi_b.h
index a709feb..4d834e1 100644
--- a/include/configs/rpi_b.h
+++ b/include/configs/rpi_b.h
@@ -50,6 +50,7 @@
 #define CONFIG_SYS_MALLOC_LEN		SZ_4M
 #define CONFIG_SYS_MEMTEST_START	0x00100000
 #define CONFIG_SYS_MEMTEST_END		0x00200000
+#define CONFIG_LOADADDR			0x00200000
 
 /* Flash */
 #define CONFIG_SYS_NO_FLASH
@@ -69,6 +70,13 @@
 #define CONFIG_VIDEO_BCM2835
 #define CONFIG_SYS_WHITE_ON_BLACK
 
+/* SD/MMC configuration */
+#define CONFIG_GENERIC_MMC
+#define CONFIG_MMC
+#define CONFIG_SDHCI
+#define CONFIG_MMC_SDHCI_IO_ACCESSORS
+#define CONFIG_BCM2835_SDHCI
+
 /* Console UART */
 #define CONFIG_PL011_SERIAL
 #define CONFIG_PL011_CLOCK		3000000
@@ -84,12 +92,59 @@
 /* Environment */
 #define CONFIG_ENV_SIZE			SZ_16K
 #define CONFIG_ENV_IS_NOWHERE
+#define CONFIG_ENV_VARS_UBOOT_CONFIG
 #define CONFIG_SYS_LOAD_ADDR		0x1000000
 #define CONFIG_CONSOLE_MUX
 #define CONFIG_SYS_CONSOLE_IS_IN_ENV
-#define CONFIG_EXTRA_ENV_SETTINGS	"stdin=serial\0" \
-					"stderr=serial,lcd\0" \
-					"stdout=serial,lcd\0"
+/*
+ * Memory layout for where various images get loaded by boot scripts:
+ *
+ * scriptaddr can be pretty much anywhere that doesn't conflict with something
+ *   else. Put it low in memory to avoid conflicts.
+ *
+ * kernel_addr_r must be within the first 128M of RAM in order for the
+ *   kernel's CONFIG_AUTO_ZRELADDR option to work. Since the kernel will
+ *   decompress itself to 0x8000 after the start of RAM, kernel_addr_r
+ *   should not overlap that area, or the kernel will have to copy itself
+ *   somewhere else before decompression. Similarly, the address of any other
+ *   data passed to the kernel shouldn't overlap the start of RAM. Pushing
+ *   this up to 16M allows for a sizable kernel to be decompressed below the
+ *   compressed load address.
+ *
+ * fdt_addr_r simply shouldn't overlap anything else. Choosing 32M allows for
+ *   the compressed kernel to be up to 16M too.
+ *
+ * ramdisk_addr_r simply shouldn't overlap anything else. Choosing 33M allows
+ *   for the FDT/DTB to be up to 1M, which is hopefully plenty.
+ */
+#define CONFIG_EXTRA_ENV_SETTINGS \
+	"stdin=serial\0" \
+	"stderr=serial,lcd\0" \
+	"stdout=serial,lcd\0" \
+	"scriptaddr=0x00000000\0" \
+	"kernel_addr_r=0x01000000\0" \
+	"fdt_addr_r=0x02000000\0" \
+	"ramdisk_addr_r=0x02100000\0" \
+	"boot_targets=mmc0\0" \
+	\
+	"script_boot=" \
+		"if fatload ${devtype} ${devnum}:1 " \
+					"${scriptaddr} boot.scr.uimg; then " \
+			"source ${scriptaddr}; " \
+		"fi;\0" \
+	\
+	"mmc_boot=" \
+		"setenv devtype mmc; " \
+		"if mmc dev ${devnum}; then " \
+			"run script_boot; " \
+		"fi\0" \
+	\
+	"bootcmd_mmc0=setenv devnum 0; run mmc_boot\0" \
+
+#define CONFIG_BOOTCOMMAND \
+	"for target in ${boot_targets}; do run bootcmd_${target}; done"
+
+#define CONFIG_BOOTDELAY		2
 
 /* Shell */
 #define CONFIG_SYS_HUSH_PARSER
@@ -104,6 +159,13 @@
 #include <config_cmd_default.h>
 #define CONFIG_CMD_BOOTZ
 #define CONFIG_CMD_GPIO
+#define CONFIG_CMD_MMC
+#define CONFIG_DOS_PARTITION
+#define CONFIG_PARTITION_UUIDS
+#define CONFIG_CMD_PART
+#define CONFIG_CMD_FS_GENERIC
+#define CONFIG_CMD_FAT
+#define CONFIG_CMD_EXT
 /* Some things don't make sense on this HW or yet */
 #undef CONFIG_CMD_FPGA
 #undef CONFIG_CMD_NET
-- 
1.7.9.5

[U-Boot] [PATCH V2 1/2] mmc: add bcm2835 driver

[Albert ARIBAUD]

Hi Stephen,

>  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

Actually the patch is essentially an MMC driver one, with the ARM
file touched only to add a base address. I have reassigned the patch to
Andy.

Amicalement,
-- 
Albert.

[U-Boot] [PATCH V2 1/2] mmc: add bcm2835 driver

[Stephen Warren]

On 11/10/2012 02:17 AM, Albert ARIBAUD wrote:
> Hi Stephen,
> 
>>  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
> 
> Actually the patch is essentially an MMC driver one, with the ARM
> file touched only to add a base address. I have reassigned the patch to
> Andy.

OK. Note that patch 2/2 is all ARM and relies on patch 1/2 to compile
though.

[U-Boot] [PATCH V2 1/2] mmc: add bcm2835 driver

[Albert ARIBAUD]

Hi Stephen,

On Sun, 11 Nov 2012 14:54:46 -0700, Stephen Warren
<swarren@wwwdotorg.org> wrote:

> On 11/10/2012 02:17 AM, Albert ARIBAUD wrote:
> > Hi Stephen,
> > 
> >>  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
> > 
> > Actually the patch is essentially an MMC driver one, with the ARM
> > file touched only to add a base address. I have reassigned the patch to
> > Andy.
> 
> OK. Note that patch 2/2 is all ARM and relies on patch 1/2 to compile
> though.

If you prefer, Andy can give his Acked-By: and reassign to me, and I
will apply the series.

Amicalement,
-- 
Albert.