From: Stephen Warren <hidden> Date: 2012-09-12 04:18:25
From: Simon Arlott <redacted>
The BCM2708 is an ARM SoC from Broadcom. It is the primary SoC in a
series which contains the BCM2835 amongst other variants. This patch
adds very basic support for this series of SoCs, under the BCM2708 name.
http://www.broadcom.com/products/BCM2835http://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripherals.pd
Note that the documentation in the latter .pdf assumes the MMU setup
that's used on the "VideoCore" companion processor, and does not document
physical peripheral addresses. Subtract 0x5e000000 to obtain the physical
addresses.
The BCM2835 SoC is used in the Raspberry Pi. This patch also adds a
minimal device tree for this board; enough to see some very early kernel
boot messages through earlyprintk. However, this patch does not yet
provide a useful booting system.
http://www.raspberrypi.org/.
This patch was extracted from git://github.com/lp0/linux.git branch
rpi-split from 3-4 months ago, and significantly stripped down and
modified since.
Signed-off-by: Chris Boot <bootc@bootc.net>
Signed-off-by: Simon Arlott <redacted>
Signed-off-by: Dom Cobley <redacted>
Signed-off-by: Dom Cobley <redacted>
Signed-off-by: Stephen Warren <redacted>
---
This version is enough to get to "Kernel panic - not syncing: No init found."
I haven't tested yet, but I expect that using an initrd should work.
v3:
* Added DT binding documentation for the SoC itself.
* Changed patch subject from "support" to "infra-structure", and added
to the commit description, to indicate that the patch isn't adding
complete support for the SoC/board.
* Added all S-o-b tags from downstream, now that I have permission to
fix them up to be valid.
* Changed patch author to Simon Arlott, now I have permission to change
his email address to something valid.
* Limited my (c) additions to files I created; the other changes turnd
out to be trivial.
v2:
* Rename *_BASE to *_PHYS to match Simon's rpi-split branch.
* Remove #define UART_BAUD since it isn't used.
* Don't select WATCHDOG from ARCH_BCM2708
* Remove 8250 and PL010 serial ports from bcm2708_defconfig
* Remove <mach/hardware.h>
* Rename common.c back to bcm2708.c; matches downstream and is
preferred naming style.
---
Documentation/devicetree/bindings/arm/bcm2708.txt | 15 ++++
arch/arm/Kconfig | 18 ++++
arch/arm/Makefile | 1 +
arch/arm/boot/dts/bcm2835-rpi-b.dts | 12 +++
arch/arm/boot/dts/bcm2835.dtsi | 10 +++
arch/arm/configs/bcm2708_defconfig | 93 +++++++++++++++++++++
arch/arm/mach-bcm2708/Makefile | 1 +
arch/arm/mach-bcm2708/Makefile.boot | 5 ++
arch/arm/mach-bcm2708/bcm2708.c | 77 +++++++++++++++++
arch/arm/mach-bcm2708/include/mach/bcm2708_soc.h | 29 +++++++
arch/arm/mach-bcm2708/include/mach/debug-macro.S | 21 +++++
arch/arm/mach-bcm2708/include/mach/timex.h | 26 ++++++
arch/arm/mach-bcm2708/include/mach/uncompress.h | 45 ++++++++++
13 files changed, 353 insertions(+)
create mode 100644 Documentation/devicetree/bindings/arm/bcm2708.txt
create mode 100644 arch/arm/boot/dts/bcm2835-rpi-b.dts
create mode 100644 arch/arm/boot/dts/bcm2835.dtsi
create mode 100644 arch/arm/configs/bcm2708_defconfig
create mode 100644 arch/arm/mach-bcm2708/Makefile
create mode 100644 arch/arm/mach-bcm2708/Makefile.boot
create mode 100644 arch/arm/mach-bcm2708/bcm2708.c
create mode 100644 arch/arm/mach-bcm2708/include/mach/bcm2708_soc.h
create mode 100644 arch/arm/mach-bcm2708/include/mach/debug-macro.S
create mode 100644 arch/arm/mach-bcm2708/include/mach/timex.h
create mode 100644 arch/arm/mach-bcm2708/include/mach/uncompress.h
@@ -0,0 +1,15 @@+Broadcom BCM2708 device tree bindings+-------------------------------------------++Boards with the BCM2708 SoC, or another SoC in the BCM2708 family, shall have+the following properties:++Required root node property:++compatible = "broadcom,bcm2708";++Boards with BCM2835 SoC shall *additionally* have the following properties:++Required root node property:++compatible = "broadcom,bcm2835";
@@ -136,6 +136,7 @@ textofs-$(CONFIG_ARCH_MSM8960) := 0x00208000# Machine directory name. This list is sorted alphanumerically# by CONFIG_* macro name.machine-$(CONFIG_ARCH_AT91):=at91+machine-$(CONFIG_ARCH_BCM2708):=bcm2708machine-$(CONFIG_ARCH_BCMRING):=bcmringmachine-$(CONFIG_ARCH_CLPS711X):=clps711xmachine-$(CONFIG_ARCH_CNS3XXX):=cns3xxx
@@ -0,0 +1,12 @@+/dts-v1/;+/memreserve/0x0c000000 0x04000000;+/include/"bcm2835.dtsi"++/{+model="Raspberry Pi Model B";+compatible="raspberrypi,model-b","broadcom,bcm2835","broadcom,bcm2708";++memory{+reg=<00x10000000>;+};+};
@@ -0,0 +1,93 @@+CONFIG_EXPERIMENTAL=y+# CONFIG_LOCALVERSION_AUTO is not set+CONFIG_SYSVIPC=y+CONFIG_BSD_PROCESS_ACCT=y+CONFIG_BSD_PROCESS_ACCT_V3=y+CONFIG_FHANDLE=y+CONFIG_NO_HZ=y+CONFIG_HIGH_RES_TIMERS=y+CONFIG_LOG_BUF_SHIFT=18+CONFIG_CGROUP_FREEZER=y+CONFIG_CGROUP_DEVICE=y+CONFIG_CPUSETS=y+CONFIG_CGROUP_CPUACCT=y+CONFIG_RESOURCE_COUNTERS=y+CONFIG_CGROUP_PERF=y+CONFIG_CFS_BANDWIDTH=y+CONFIG_RT_GROUP_SCHED=y+CONFIG_NAMESPACES=y+CONFIG_SCHED_AUTOGROUP=y+CONFIG_RELAY=y+CONFIG_BLK_DEV_INITRD=y+CONFIG_RD_BZIP2=y+CONFIG_RD_LZMA=y+CONFIG_RD_XZ=y+CONFIG_RD_LZO=y+CONFIG_CC_OPTIMIZE_FOR_SIZE=y+CONFIG_KALLSYMS_ALL=y+CONFIG_EMBEDDED=y+# CONFIG_COMPAT_BRK is not set+CONFIG_PROFILING=y+CONFIG_OPROFILE=y+CONFIG_JUMP_LABEL=y+# CONFIG_BLOCK is not set+CONFIG_ARCH_BCM2708=y+CONFIG_PREEMPT_VOLUNTARY=y+CONFIG_COMPACTION=y+CONFIG_KSM=y+CONFIG_DEFAULT_MMAP_MIN_ADDR=65536+CONFIG_CLEANCACHE=y+CONFIG_SECCOMP=y+CONFIG_CC_STACKPROTECTOR=y+CONFIG_KEXEC=y+CONFIG_CRASH_DUMP=y+# CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set+# CONFIG_SUSPEND is not set+CONFIG_DEVTMPFS=y+CONFIG_DEVTMPFS_MOUNT=y+# CONFIG_STANDALONE is not set+# CONFIG_INPUT_MOUSEDEV is not set+# CONFIG_INPUT_KEYBOARD is not set+# CONFIG_INPUT_MOUSE is not set+# CONFIG_SERIO is not set+# CONFIG_VT is not set+# CONFIG_UNIX98_PTYS is not set+# CONFIG_LEGACY_PTYS is not set+# CONFIG_DEVKMEM is not set+CONFIG_SERIAL_AMBA_PL011=y+CONFIG_SERIAL_AMBA_PL011_CONSOLE=y+CONFIG_TTY_PRINTK=y+# CONFIG_HW_RANDOM is not set+# CONFIG_HWMON is not set+# CONFIG_USB_SUPPORT is not set+# CONFIG_IOMMU_SUPPORT is not set+# CONFIG_FILE_LOCKING is not set+# CONFIG_DNOTIFY is not set+# CONFIG_INOTIFY_USER is not set+# CONFIG_PROC_FS is not set+# CONFIG_SYSFS is not set+# CONFIG_MISC_FILESYSTEMS is not set+CONFIG_PRINTK_TIME=y+# CONFIG_ENABLE_WARN_DEPRECATED is not set+# CONFIG_ENABLE_MUST_CHECK is not set+CONFIG_UNUSED_SYMBOLS=y+CONFIG_LOCKUP_DETECTOR=y+CONFIG_DEBUG_INFO=y+CONFIG_DEBUG_MEMORY_INIT=y+CONFIG_BOOT_PRINTK_DELAY=y+CONFIG_SCHED_TRACER=y+CONFIG_STACK_TRACER=y+CONFIG_FUNCTION_PROFILER=y+CONFIG_DYNAMIC_DEBUG=y+CONFIG_KGDB=y+CONFIG_KGDB_KDB=y+CONFIG_TEST_KSTRTOX=y+CONFIG_STRICT_DEVMEM=y+CONFIG_DEBUG_LL=y+CONFIG_EARLY_PRINTK=y+# CONFIG_XZ_DEC_X86 is not set+# CONFIG_XZ_DEC_POWERPC is not set+# CONFIG_XZ_DEC_IA64 is not set+# CONFIG_XZ_DEC_ARM is not set+# CONFIG_XZ_DEC_ARMTHUMB is not set+# CONFIG_XZ_DEC_SPARC is not set
From: Stephen Warren <hidden> Date: 2012-09-12 04:18:26
From: Simon Arlott <redacted>
The BCM2708 contains a custom interrupt controller, which supports 72
interrupt sources using a 2-level register scheme. The interrupt
controller, or the HW block containing it, is referred to occasionally
as "armctrl" in the SoC documentation, hence the symbol naming in the
code.
This patch was extracted from git://github.com/lp0/linux.git branch
rpi-split as of 2012/09/08, and modified as follows:
* Added devicetree documentation, and hence removed list of IRQs from
bcm2835.dtsi.
* Changed shift in MAKE_HWIRQ() and HWIRQ_BANK() from 8 to 5 to reduce
the size of the hwirq space, and pass the total size of the hwirq space
to irq_domain_add_linear(), rather than just the number of valid hwirqs;
the two are different due to the hwirq space being sparse.
* Added the interrupt controller DT node to the top-level of the DT,
rather than nesting it inside a /axi node. Hence, changed the reg value
since /axi had a ranges property. This seems simpler to me, but I'm not
sure if everyone will like this change or not.
* Don't set struct irq_domain_ops.map = irq_domain_simple_map, hence
removing the need to patch include/linux/irqdomain.h or
kernel/irq/irqdomain.c.
* Removed unused IS_VALID_BANK()/IS_VALID_IRQ() macros.
* Renamed armctrl_handle_irq() to prevent possible symbol clashes.
* Made armctrl_of_init() static.
* Removed comment "Each bank is registered as a separate interrupt
controller" since this is no longer true.
* Removed FSF address from license header.
* Added my name to copyright header.
Signed-off-by: Chris Boot <bootc@bootc.net>
Signed-off-by: Simon Arlott <redacted>
Signed-off-by: Dom Cobley <redacted>
Signed-off-by: Dom Cobley <redacted>
Signed-off-by: Stephen Warren <redacted>
--
v3: New patch.
TODO: Should of_address_to_resource(), ioremap(), request_mem_region()
in armctrl_of_init() be collapsed into of_iomap(). This wouldn't request
the region, but a quick grep implies that's quite common with DT.
---
.../arm/bcm2708/broadcom,bcm2708-armctrl-ic.txt | 110 +++++++++
arch/arm/boot/dts/bcm2835.dtsi | 8 +
arch/arm/mach-bcm2708/Makefile | 1 +
arch/arm/mach-bcm2708/bcm2708.c | 12 +-
arch/arm/mach-bcm2708/irq.c | 234 ++++++++++++++++++++
arch/arm/mach-bcm2708/irq.h | 27 +++
6 files changed, 383 insertions(+), 9 deletions(-)
create mode 100644 Documentation/devicetree/bindings/arm/bcm2708/broadcom,bcm2708-armctrl-ic.txt
create mode 100644 arch/arm/mach-bcm2708/irq.c
create mode 100644 arch/arm/mach-bcm2708/irq.h
@@ -0,0 +1,110 @@+BCM2708 Top-Level ("ARMCTRL") Interrupt Controller++The BCM2708 contains a custom top-level interrupt controller, which supports+72 interrupt sources using a 2-level register scheme. The interrupt+controller, or the HW block containing it, is referred to occasionally+as "armctrl" in the SoC documentation, hence naming of this binding.++Required properties:++- compatible : should be "broadcom,bcm2708-armctrl-ic.txt"+- reg : Specifies base physical address and size of the registers.+- interrupt-controller : Identifies the node as an interrupt controller+- #interrupt-cells : Specifies the number of cells needed to encode an+ interrupt source. The value shall be 2.++ The 1st cell is the interrupt bank; 0 for interrupts in the "IRQ basic+ pending" register, or 1/2 respectively for interrupts in the "IRQ pending+ 1/2" register.++ The 2nd cell contains the interrupt number within the bank. Valid values+ are 0..7 for bank 0, and 0..31 for bank 1.++The interrupt sources are as follows, for the BCM2835 derivative SoC at least:++Bank 0:+0: ARM_TIMER+1: ARM_MAILBOX+2: ARM_DOORBELL_0+3: ARM_DOORBELL_1+4: VPU0_HALTED+5: VPU1_HALTED+6: ILLEGAL_TYPE0+7: ILLEGAL_TYPE1++Bank 1:+0: TIMER0+1: TIMER1+2: TIMER2+3: TIMER3+4: CODEC0+5: CODEC1+6: CODEC2+7: VC_JPEG+8: ISP+9: VC_USB+10: VC_3D+11: TRANSPOSER+12: MULTICORESYNC0+13: MULTICORESYNC1+14: MULTICORESYNC2+15: MULTICORESYNC3+16: DMA0+17: DMA1+18: VC_DMA2+19: VC_DMA3+20: DMA4+21: DMA5+22: DMA6+23: DMA7+24: DMA8+25: DMA9+26: DMA10+27: DMA11+28: DMA12+29: AUX+30: ARM+31: VPUDMA++Bank 2:+0: HOSTPORT+1: VIDEOSCALER+2: CCP2TX+3: SDC+4: DSI0+5: AVE+6: CAM0+7: CAM1+8: HDMI0+9: HDMI1+10: PIXELVALVE1+11: I2CSPISLV+12: DSI1+13: PWA0+14: PWA1+15: CPR+16: SMI+17: GPIO0+18: GPIO1+19: GPIO2+20: GPIO3+21: VC_I2C+22: VC_SPI+23: VC_I2SPCM+24: VC_SDIO+25: VC_UART+26: SLIMBUS+27: VEC+28: CPG+29: RNG+30: VC_ARASANSDIO+31: AVSPMON++Example:++intc: interrupt-controller {+ compatible = "broadcom,bcm2708-armctrl-ic";+ reg = <0x2000b200 0x200>;+ interrupt-controller;+ #interrupt-cells = <2>;+};
@@ -0,0 +1,234 @@+/*+*Copyright2010Broadcom+*Copyright2012SimonArlott,ChrisBoot,StephenWarren+*+*Thisprogramisfreesoftware;youcanredistributeitand/ormodify+*itunderthetermsoftheGNUGeneralPublicLicenseaspublishedby+*theFreeSoftwareFoundation;eitherversion2oftheLicense,or+*(atyouroption)anylaterversion.+*+*Thisprogramisdistributedinthehopethatitwillbeuseful,+*butWITHOUTANYWARRANTY;withouteventheimpliedwarrantyof+*MERCHANTABILITYorFITNESSFORAPARTICULARPURPOSE.Seethe+*GNUGeneralPublicLicenseformoredetails.+*+*Quirk1:Shortcutinterruptsdon'tsetthebank1/2registerpendingbits+*+*Ifaninterruptfiresonbank1thatisn'tintheshortcutslist,bit8+*onbank0issettosignifythataninterruptinbank1hasfired,and+*tolookinthebank1statusregisterformoreinformation.+*+*Ifaninterruptfiresonbank1that_is_intheshortcutslist,its+*shortcutbitinbank0issetaswellasitsinterruptbitinthebank1+*statusregister,butbank0bit8is_not_set.+*+*Quirk2:Youcan'tmasktheregister1/2pendinginterrupts+*+*Inapropercascadedinterruptcontroller,theinterruptlineswith+*cascadedinterruptcontrollersonthemarejustnormalinterruptlines.+*Youcanmasktheinterruptsandgetonwiththings.Withthiscontroller+*youcan'tdothat.+*+*Quirk3:Theshortcutinterruptscan'tbe(un)maskedinbank0+*+*Thoseinterruptsthathaveshortcutscanonlybemasked/unmaskedin+*theirrespectivebanks'enable/disableregisters.Doingsointhebank0+*enable/disableregistershasnoeffect.+*+*TheFIQcontrolregister:+*Bits0-6:IRQ(indexinorderofinterruptsfrombanks1,2,then0)+*Bit7:EnableFIQgeneration+*Bits8+:Unused+*+*AninterruptmustbedisabledbeforeconfiguringitforFIQgeneration+*otherwisebothhandlerswillfireatthesametime!+*/++#include<linux/io.h>+#include<linux/slab.h>+#include<linux/of_address.h>+#include<linux/of_irq.h>+#include<linux/irqdomain.h>+#include<asm/exception.h>++#include"irq.h"++/* Put the bank and irq (32 bits) into the hwirq */+#define MAKE_HWIRQ(b, n) ((b << 5) | (n))+#define HWIRQ_BANK(i) (i >> 5)+#define HWIRQ_BIT(i) BIT(i & 0x1f)++#define NR_IRQS_BANK0 8+#define BANK0_HWIRQ_MASK 0xff+/* Shortcuts can't be disabled so any unknown new ones need to be masked */+#define SHORTCUT1_MASK 0x00007c00+#define SHORTCUT2_MASK 0x001f8000+#define SHORTCUT_SHIFT 10+#define BANK1_HWIRQ BIT(8)+#define BANK2_HWIRQ BIT(9)+#define BANK0_VALID_MASK (BANK0_HWIRQ_MASK | BANK1_HWIRQ | BANK2_HWIRQ \+|SHORTCUT1_MASK|SHORTCUT2_MASK)++#define REG_FIQ_CONTROL 0x0c++#define NR_BANKS 3+#define IRQS_PER_BANK 32++staticintreg_pending[]__initconst={0x00,0x04,0x08};+staticintreg_enable[]__initconst={0x18,0x10,0x14};+staticintreg_disable[]__initconst={0x24,0x1c,0x20};+staticintbank_irqs[]__initconst={8,32,32};++staticconstintshortcuts[]={+7,9,10,18,19,/* Bank 1 */+21,22,23,24,25,30/* Bank 2 */+};++structarmctrl_ic{+void__iomem*base;+void__iomem*pending[NR_BANKS];+void__iomem*enable[NR_BANKS];+void__iomem*disable[NR_BANKS];+structirq_domain*domain;+};++staticstructarmctrl_icintc__read_mostly;++staticvoidarmctrl_mask_irq(structirq_data*d)+{+writel_relaxed(HWIRQ_BIT(d->hwirq),intc.disable[HWIRQ_BANK(d->hwirq)]);+}++staticvoidarmctrl_unmask_irq(structirq_data*d)+{+writel_relaxed(HWIRQ_BIT(d->hwirq),intc.enable[HWIRQ_BANK(d->hwirq)]);+}++staticstructirq_chiparmctrl_chip={+.name="ARMCTRL-level",+.irq_mask=armctrl_mask_irq,+.irq_unmask=armctrl_unmask_irq+};++staticintarmctrl_xlate(structirq_domain*d,structdevice_node*ctrlr,+constu32*intspec,unsignedintintsize,+unsignedlong*out_hwirq,unsignedint*out_type)+{+if(WARN_ON(intsize!=2))+return-EINVAL;++if(WARN_ON(intspec[0]>=NR_BANKS))+return-EINVAL;++if(WARN_ON(intspec[1]>=IRQS_PER_BANK))+return-EINVAL;++if(WARN_ON(intspec[0]==0&&intspec[1]>=NR_IRQS_BANK0))+return-EINVAL;++*out_hwirq=MAKE_HWIRQ(intspec[0],intspec[1]);+*out_type=IRQ_TYPE_NONE;+return0;+}++staticstructirq_domain_opsarmctrl_ops={+.xlate=armctrl_xlate+};++staticint__initarmctrl_of_init(structdevice_node*node,+structdevice_node*parent)+{+structresourceres;+void__iomem*base;+intret,irq,b,i;++ret=of_address_to_resource(node,0,&res);+if(ret)+panic("%s: unable to find IC registers\n",+node->full_name);++base=ioremap(res.start,resource_size(&res));+if(!base)+panic("%s: unable to map IC registers\n",+node->full_name);++if(!request_mem_region(res.start,resource_size(&res),+node->full_name))+panic("%s: unable to request resources for IC registers\n",+node->full_name);++intc.domain=irq_domain_add_linear(node,MAKE_HWIRQ(NR_BANKS,0),+&armctrl_ops,NULL);+if(!intc.domain)+panic("%s: unable to create IRQ domain\n",node->full_name);++for(b=0;b<NR_BANKS;b++){+intc.pending[b]=base+reg_pending[b];+intc.enable[b]=base+reg_enable[b];+intc.disable[b]=base+reg_disable[b];++for(i=0;i<bank_irqs[b];i++){+irq=irq_create_mapping(intc.domain,MAKE_HWIRQ(b,i));+BUG_ON(irq<=0);+irq_set_chip_and_handler(irq,&armctrl_chip,+handle_level_irq);+set_irq_flags(irq,IRQF_VALID|IRQF_PROBE);+}+}+return0;+}++staticstructof_device_idirq_of_match[]__initconst={+{.compatible="broadcom,bcm2708-armctrl-ic",.data=armctrl_of_init}+};++void__initbcm2708_init_irq(void)+{+of_irq_init(irq_of_match);+}++/*+*Handleeachinterruptacrosstheentireinterruptcontroller.Thisreadsthe+*statusregisterbeforehandlingeachinterrupt,whichisnecessarygiventhat+*handle_IRQmaybrieflyre-enableinterruptsforsoftIRQhandling.+*/++staticvoidarmctrl_handle_bank(intbank,structpt_regs*regs)+{+u32stat,irq;++while((stat=readl_relaxed(intc.pending[bank]))){+irq=MAKE_HWIRQ(bank,ffs(stat)-1);+handle_IRQ(irq_linear_revmap(intc.domain,irq),regs);+}+}++staticvoidarmctrl_handle_shortcut(intbank,structpt_regs*regs,+u32stat)+{+u32irq=MAKE_HWIRQ(bank,shortcuts[ffs(stat>>SHORTCUT_SHIFT)-1]);+handle_IRQ(irq_linear_revmap(intc.domain,irq),regs);+}++asmlinkagevoid__exception_irq_entrybcm2708_armctrl_handle_irq(+structpt_regs*regs)+{+u32stat,irq;++while((stat=readl_relaxed(intc.pending[0])&BANK0_VALID_MASK)){+if(stat&BANK0_HWIRQ_MASK){+irq=MAKE_HWIRQ(0,ffs(stat&BANK0_HWIRQ_MASK)-1);+handle_IRQ(irq_linear_revmap(intc.domain,irq),regs);+}elseif(stat&SHORTCUT1_MASK){+armctrl_handle_shortcut(1,regs,stat&SHORTCUT1_MASK);+}elseif(stat&SHORTCUT2_MASK){+armctrl_handle_shortcut(2,regs,stat&SHORTCUT2_MASK);+}elseif(stat&BANK1_HWIRQ){+armctrl_handle_bank(1,regs);+}elseif(stat&BANK2_HWIRQ){+armctrl_handle_bank(2,regs);+}else{+BUG();+}+}+}
On Wednesday 12 September 2012, Stephen Warren wrote:
From: Simon Arlott <redacted>
The BCM2708 contains a custom interrupt controller, which supports 72
interrupt sources using a 2-level register scheme. The interrupt
controller, or the HW block containing it, is referred to occasionally
as "armctrl" in the SoC documentation, hence the symbol naming in the
code.
This patch was extracted from git://github.com/lp0/linux.git branch
rpi-split as of 2012/09/08, and modified as follows:
* Added devicetree documentation, and hence removed list of IRQs from
bcm2835.dtsi.
* Changed shift in MAKE_HWIRQ() and HWIRQ_BANK() from 8 to 5 to reduce
the size of the hwirq space, and pass the total size of the hwirq space
to irq_domain_add_linear(), rather than just the number of valid hwirqs;
the two are different due to the hwirq space being sparse.
If the IRQ space is very sparse, isn't it better to use a tree domain
rather than a linear one?
* Added the interrupt controller DT node to the top-level of the DT,
rather than nesting it inside a /axi node. Hence, changed the reg value
since /axi had a ranges property. This seems simpler to me, but I'm not
sure if everyone will like this change or not.
The layout should follow what the hardware looks like. If the interrupt
controller is connected through axi, then I'd suggest describing it there
unless there is a strong reason not to. The interrupt-parent property
of the root node can easily point anywhere.
TODO: Should of_address_to_resource(), ioremap(), request_mem_region()
in armctrl_of_init() be collapsed into of_iomap(). This wouldn't request
the region, but a quick grep implies that's quite common with DT.
The bindings are normally grouped by subsystem, not by manufacturer or soc,
because a lot of components end up getting reused by other people. For
some reason, we have put a lot of interrupt controller bindings into the
arm subdirectory, so you can keep doing this, but I would not create a hierarchy
below that.
I think it would be even better if we could put them all into
bindings/interrupt-controller or similar.
quoted hunk
@@ -0,0 +1,110 @@+BCM2708 Top-Level ("ARMCTRL") Interrupt Controller++The BCM2708 contains a custom top-level interrupt controller, which supports+72 interrupt sources using a 2-level register scheme. The interrupt+controller, or the HW block containing it, is referred to occasionally+as "armctrl" in the SoC documentation, hence naming of this binding.
Do we actually know that BCM2708 has the same one, or could it be present
just on bcm2835? It seem hard to find any information about bcm2708,
so I don't feel too good about using that name in bindings.
We're starting to put interrupt controller drivers into drivers/irqchip
in v3.7, so maybe you can put this one there too. We will get a trivial
merge conflict with the Makefile, but that's ok IMHO.
I'm not sure if readl_relaxed() is appropriate here, or if you need readl().
If you have an MSI type interrupt signaling the completion of a DMA, you
need to ensure ordering between the data transfer and the interrupt
notification.
Arnd
From: Stephen Warren <hidden> Date: 2012-09-13 01:12:32
On 09/12/2012 04:37 AM, Arnd Bergmann wrote:
On Wednesday 12 September 2012, Stephen Warren wrote:
quoted
From: Simon Arlott <redacted>
The BCM2708 contains a custom interrupt controller, which supports 72
interrupt sources using a 2-level register scheme. The interrupt
controller, or the HW block containing it, is referred to occasionally
as "armctrl" in the SoC documentation, hence the symbol naming in the
code.
This patch was extracted from git://github.com/lp0/linux.git branch
rpi-split as of 2012/09/08, and modified as follows:
* Added devicetree documentation, and hence removed list of IRQs from
bcm2835.dtsi.
* Changed shift in MAKE_HWIRQ() and HWIRQ_BANK() from 8 to 5 to reduce
the size of the hwirq space, and pass the total size of the hwirq space
to irq_domain_add_linear(), rather than just the number of valid hwirqs;
the two are different due to the hwirq space being sparse.
If the IRQ space is very sparse, isn't it better to use a tree domain
rather than a linear one?
It's not very sparse. There are 3 banks, each containing up to 32
interrupts. However, the first bank actually only has 8 interrupts plus
2 cascade inputs (which are hidden inside the interrupt controller
driver and so not exposed). So, it's more like there's one gap in the
middle. I don't know much about the tree domain, but I figure it's
probably not worth it.
quoted
* Added the interrupt controller DT node to the top-level of the DT,
rather than nesting it inside a /axi node. Hence, changed the reg value
since /axi had a ranges property. This seems simpler to me, but I'm not
sure if everyone will like this change or not.
The layout should follow what the hardware looks like. If the interrupt
controller is connected through axi, then I'd suggest describing it there
unless there is a strong reason not to. The interrupt-parent property
of the root node can easily point anywhere.
The problem is that there's no documentation of the actual bus
structure. Simon's original patch placed all peripherals under a single
top-level /axi bus/node, but the documentation mentions all of AXI, APB,
and AHB in passing, but doesn't explicitly describe which peripherals
are on which bus etc. I think I'd rather not represent the bus structure
in the .dtsi file at all, rather than represent just part of the
structure and hence be misleading.
quoted
@@ -0,0 +1,110 @@+BCM2708 Top-Level ("ARMCTRL") Interrupt Controller++The BCM2708 contains a custom top-level interrupt controller, which supports+72 interrupt sources using a 2-level register scheme. The interrupt+controller, or the HW block containing it, is referred to occasionally+as "armctrl" in the SoC documentation, hence naming of this binding.
Do we actually know that BCM2708 has the same one, or could it be present
just on bcm2835? It seem hard to find any information about bcm2708,
so I don't feel too good about using that name in bindings.
I don't know anything at all about the BCM2708 really. Perhaps Dom at
Broadcom can fill in some details?
A similar discussion was apparently held downstream, and IIRC the
reported decision there was that BCM2708 was the "parent" of a family of
SoCs, so they made all the DT stuff compatible with both 2708 and 2835.
Given the lack of documentation, I'd be quite happy to rework all of
this to say just BCM2835 instead, and drop any reference to BCM2708 at
all. Should I just go ahead and do that?
I'm not sure if readl_relaxed() is appropriate here, or if you need readl().
If you have an MSI type interrupt signaling the completion of a DMA, you
need to ensure ordering between the data transfer and the interrupt
notification.
I did wonder about this. I suppose it would be safe to globally replace
all readl/writel_relaxed with plain readl/writel, and fix this up later
if we can justify it. Should I go ahead and do that?
On Thursday 13 September 2012, Stephen Warren wrote:
On 09/12/2012 04:37 AM, Arnd Bergmann wrote:
quoted
If the IRQ space is very sparse, isn't it better to use a tree domain
rather than a linear one?
It's not very sparse. There are 3 banks, each containing up to 32
interrupts. However, the first bank actually only has 8 interrupts plus
2 cascade inputs (which are hidden inside the interrupt controller
driver and so not exposed). So, it's more like there's one gap in the
middle. I don't know much about the tree domain, but I figure it's
probably not worth it.
Ok, makes sense.
quoted
quoted
* Added the interrupt controller DT node to the top-level of the DT,
rather than nesting it inside a /axi node. Hence, changed the reg value
since /axi had a ranges property. This seems simpler to me, but I'm not
sure if everyone will like this change or not.
The layout should follow what the hardware looks like. If the interrupt
controller is connected through axi, then I'd suggest describing it there
unless there is a strong reason not to. The interrupt-parent property
of the root node can easily point anywhere.
The problem is that there's no documentation of the actual bus
structure. Simon's original patch placed all peripherals under a single
top-level /axi bus/node, but the documentation mentions all of AXI, APB,
and AHB in passing, but doesn't explicitly describe which peripherals
are on which bus etc. I think I'd rather not represent the bus structure
in the .dtsi file at all, rather than represent just part of the
structure and hence be misleading.
Ok.
quoted
quoted
@@ -0,0 +1,110 @@+BCM2708 Top-Level ("ARMCTRL") Interrupt Controller++The BCM2708 contains a custom top-level interrupt controller, which supports+72 interrupt sources using a 2-level register scheme. The interrupt+controller, or the HW block containing it, is referred to occasionally+as "armctrl" in the SoC documentation, hence naming of this binding.
Do we actually know that BCM2708 has the same one, or could it be present
just on bcm2835? It seem hard to find any information about bcm2708,
so I don't feel too good about using that name in bindings.
I don't know anything at all about the BCM2708 really. Perhaps Dom at
Broadcom can fill in some details?
A similar discussion was apparently held downstream, and IIRC the
reported decision there was that BCM2708 was the "parent" of a family of
SoCs, so they made all the DT stuff compatible with both 2708 and 2835.
Given the lack of documentation, I'd be quite happy to rework all of
this to say just BCM2835 instead, and drop any reference to BCM2708 at
all. Should I just go ahead and do that?
I'm not sure if readl_relaxed() is appropriate here, or if you need readl().
If you have an MSI type interrupt signaling the completion of a DMA, you
need to ensure ordering between the data transfer and the interrupt
notification.
I did wonder about this. I suppose it would be safe to globally replace
all readl/writel_relaxed with plain readl/writel, and fix this up later
if we can justify it. Should I go ahead and do that?
The synchronizations can be a bit expensive, so in the interrupt controller
driver it makes sense to use at least writel_relaxed, which should always
be fine because you don't have to worry about outgoing DMAs.
Even for incoming DMA, I think there is only a need for the non-relaxed
version if we're actually dealing with MSI interrupts, because regular
level and edge triggered interrupts have no form of synchronization between
DMA completion and interrupt delivery anyway.
Arnd
From: Stephen Warren <hidden> Date: 2012-09-14 02:21:14
On 09/13/2012 04:45 AM, Arnd Bergmann wrote:
On Thursday 13 September 2012, Stephen Warren wrote:
quoted
On 09/12/2012 04:37 AM, Arnd Bergmann wrote:
quoted
quoted
quoted
@@ -0,0 +1,110 @@+BCM2708 Top-Level ("ARMCTRL") Interrupt Controller++The BCM2708 contains a custom top-level interrupt controller, which supports+72 interrupt sources using a 2-level register scheme. The interrupt+controller, or the HW block containing it, is referred to occasionally+as "armctrl" in the SoC documentation, hence naming of this binding.
Do we actually know that BCM2708 has the same one, or could it be present
just on bcm2835? It seem hard to find any information about bcm2708,
so I don't feel too good about using that name in bindings.
I don't know anything at all about the BCM2708 really. Perhaps Dom at
Broadcom can fill in some details?
A similar discussion was apparently held downstream, and IIRC the
reported decision there was that BCM2708 was the "parent" of a family of
SoCs, so they made all the DT stuff compatible with both 2708 and 2835.
Given the lack of documentation, I'd be quite happy to rework all of
this to say just BCM2835 instead, and drop any reference to BCM2708 at
all. Should I just go ahead and do that?
That's probably safer, yes.
Sounds good. For reference, I found:
https://github.com/raspberrypi/linux/issues/22
... where it sounds like BCM2708 isn't actually a chip at all, but a
family name, so that supports this change.
I'm not sure if readl_relaxed() is appropriate here, or if you need readl().
If you have an MSI type interrupt signaling the completion of a DMA, you
need to ensure ordering between the data transfer and the interrupt
notification.
I did wonder about this. I suppose it would be safe to globally replace
all readl/writel_relaxed with plain readl/writel, and fix this up later
if we can justify it. Should I go ahead and do that?
The synchronizations can be a bit expensive, so in the interrupt controller
driver it makes sense to use at least writel_relaxed, which should always
be fine because you don't have to worry about outgoing DMAs.
Thinking some more about this - I doubt there are any MSI-style
interrupts; there's certainly no PCI/PCIe on the Raspberry Pi board, and
none documented in the SoC itself (although admittedly only a small
subset of the SoC is publicly documented). I guess it's easiest just to
leave that code as-is, and fix it up if the hardware ever turns out to
be more complex, and actually have MSI.
From: Stephen Warren <hidden> Date: 2012-09-12 04:18:27
From: Simon Arlott <redacted>
The System Timer peripheral provides four 32-bit timer channels and a
single 64-bit free running counter. Each channel has an output compare
register, which is compared against the 32 least significant bits of the
free running counter values, and generates an interrupt.
Timer 3 is used as the Linux timer.
The BCM2708 also contains an SP804-based timer module. However, it
apparently has significant differences from the standard SP804 IP block,
and Broadcom's documentation recommends using the system timer instead.
This patch was extracted from git://github.com/lp0/linux.git branch
rpi-split as of 2012/09/08, and modified as follows:
* Moved struct sys_timer bcm2708_timer into time.c to encapsulate it more.
* Added DT binding docs.
* Moved to drivers/clocksource/. This looks like the desired location for
such code now.
* Simplified bcm2708_time_init() to find one matching node and operate on
it, rather than looping over all matching nodes. This seems more
consistent with other clocksource code.
* Renamed struct bcm2708_timer.index to match_mask to better represent its
purpose.
* s/printk(PR_INFO/pr_info(/
Signed-off-by: Chris Boot <bootc@bootc.net>
Signed-off-by: Simon Arlott <redacted>
Signed-off-by: Dom Cobley <redacted>
Signed-off-by: Dom Cobley <redacted>
Signed-off-by: Stephen Warren <redacted>
---
v3: New patch.
TODO: Should of_address_to_resource(), ioremap(), request_mem_region()
in bcm2708_time_init() be collapsed into of_iomap(). This wouldn't request
the region, but a quick grep implies that's quite common with DT.
---
.../arm/bcm2708/broadcom,bcm2708-system-timer.txt | 22 +++
arch/arm/boot/dts/bcm2835.dtsi | 7 +
arch/arm/mach-bcm2708/bcm2708.c | 10 +-
drivers/clocksource/Makefile | 1 +
drivers/clocksource/bcm2708_timer.c | 170 ++++++++++++++++++++
include/linux/bcm2708_timer.h | 22 +++
6 files changed, 223 insertions(+), 9 deletions(-)
create mode 100644 Documentation/devicetree/bindings/arm/bcm2708/broadcom,bcm2708-system-timer.txt
create mode 100644 drivers/clocksource/bcm2708_timer.c
create mode 100644 include/linux/bcm2708_timer.h
@@ -0,0 +1,22 @@+BCM2708 System Timer++The System Timer peripheral provides four 32-bit timer channels and a+single 64-bit free running counter. Each channel has an output compare+register, which is compared against the 32 least significant bits of the+free running counter values, and generates an interrupt.++Required properties:++- compatible : should be "broadcom,bcm2708-system-timer.txt"+- reg : Specifies base physical address and size of the registers.+- interrupts : A list of 4 interrupt sinks; one per timer channel.+- clock-frequency : The frequency of the clock that drives the counter, in Hz.++Example:++timer {+ compatible = "broadcom,bcm2835-system-timer", "broadcom,bcm2708-system-timer";+ reg = <0x20003000 0x1000>;+ interrupts = <1 0>, <1 1>, <1 2>, <1 3>;+ clock-frequency = <1000000>;+};
On Wednesday 12 September 2012, Stephen Warren wrote:
From: Simon Arlott <redacted>
The System Timer peripheral provides four 32-bit timer channels and a
single 64-bit free running counter. Each channel has an output compare
register, which is compared against the 32 least significant bits of the
free running counter values, and generates an interrupt.
Timer 3 is used as the Linux timer.
The BCM2708 also contains an SP804-based timer module. However, it
apparently has significant differences from the standard SP804 IP block,
and Broadcom's documentation recommends using the system timer instead.
This patch was extracted from git://github.com/lp0/linux.git branch
rpi-split as of 2012/09/08, and modified as follows:
* Moved struct sys_timer bcm2708_timer into time.c to encapsulate it more.
* Added DT binding docs.
* Moved to drivers/clocksource/. This looks like the desired location for
such code now.
* Simplified bcm2708_time_init() to find one matching node and operate on
it, rather than looping over all matching nodes. This seems more
consistent with other clocksource code.
* Renamed struct bcm2708_timer.index to match_mask to better represent its
purpose.
* s/printk(PR_INFO/pr_info(/
Signed-off-by: Chris Boot <bootc@bootc.net>
Signed-off-by: Simon Arlott <redacted>
Signed-off-by: Dom Cobley <redacted>
Signed-off-by: Dom Cobley <redacted>
Signed-off-by: Stephen Warren <redacted>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Looks good to me, but I think the use of of_iomap() would be a good
simplification of the init function.
Arnd
From: Stephen Warren <hidden> Date: 2012-09-12 04:18:28
From: Simon Arlott <redacted>
This patch adds a minimal stub clock driver for the BCM2708. Its sole
purpose is to allow the PL011 AMBA clk_get() API calls to provide
something that looks enough like a clock that the driver probes and
operates correctly.
This patch was extracted from git://github.com/lp0/linux.git branch
rpi-split as of 2012/09/08, and modified as follows:
* Modified .dev_id for UART clocks to match UART DT node names.
Signed-off-by: Chris Boot <bootc@bootc.net>
Signed-off-by: Simon Arlott <redacted>
Signed-off-by: Dom Cobley <redacted>
Signed-off-by: Dom Cobley <redacted>
Signed-off-by: Stephen Warren <redacted>
--
v3: New patch.
---
arch/arm/mach-bcm2708/Makefile | 1 +
arch/arm/mach-bcm2708/bcm2708.c | 3 +++
arch/arm/mach-bcm2708/clock.c | 53 +++++++++++++++++++++++++++++++++++++++
arch/arm/mach-bcm2708/clock.h | 24 ++++++++++++++++++
4 files changed, 81 insertions(+)
create mode 100644 arch/arm/mach-bcm2708/clock.c
create mode 100644 arch/arm/mach-bcm2708/clock.h
On Wednesday 12 September 2012, Stephen Warren wrote:
From: Simon Arlott <redacted>
This patch adds a minimal stub clock driver for the BCM2708. Its sole
purpose is to allow the PL011 AMBA clk_get() API calls to provide
something that looks enough like a clock that the driver probes and
operates correctly.
This patch was extracted from git://github.com/lp0/linux.git branch
rpi-split as of 2012/09/08, and modified as follows:
* Modified .dev_id for UART clocks to match UART DT node names.
Signed-off-by: Chris Boot <bootc@bootc.net>
Signed-off-by: Simon Arlott <redacted>
Signed-off-by: Dom Cobley <redacted>
Signed-off-by: Dom Cobley <redacted>
Signed-off-by: Stephen Warren <redacted>
--
v3: New patch.
---
arch/arm/mach-bcm2708/Makefile | 1 +
arch/arm/mach-bcm2708/bcm2708.c | 3 +++
arch/arm/mach-bcm2708/clock.c | 53 +++++++++++++++++++++++++++++++++++++++
arch/arm/mach-bcm2708/clock.h | 24 ++++++++++++++++++
4 files changed, 81 insertions(+)
create mode 100644 arch/arm/mach-bcm2708/clock.c
create mode 100644 arch/arm/mach-bcm2708/clock.h
I think you should keep Mike on Cc for clock related patches. I also wonder
whether this file should go into drivers/clk right away, since that is where
it would end up when it grows into a full clock driver.
Arnd
From: Stephen Warren <hidden> Date: 2012-09-12 04:18:29
From: Simon Arlott <redacted>
This patch was extracted from git://github.com/lp0/linux.git branch
rpi-split as of 2012/09/08, and modified as follows:
* Modified UART DT node to use a unit-address to differentiate UART node
names, rather than using different base names "uart0" and "uart1".
Note that UART 1 (the Broadcom "mini UART") is not yet present, but
I'm naming the DT node in anticipation that it will be added.
Signed-off-by: Chris Boot <bootc@bootc.net>
Signed-off-by: Simon Arlott <redacted>
Signed-off-by: Dom Cobley <redacted>
Signed-off-by: Dom Cobley <redacted>
Signed-off-by: Stephen Warren <redacted>
--
v3: New patch.
---
arch/arm/boot/dts/bcm2835.dtsi | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
On Wednesday 12 September 2012, Stephen Warren wrote:
From: Simon Arlott <redacted>
This patch was extracted from git://github.com/lp0/linux.git branch
rpi-split as of 2012/09/08, and modified as follows:
* Modified UART DT node to use a unit-address to differentiate UART node
names, rather than using different base names "uart0" and "uart1".
Note that UART 1 (the Broadcom "mini UART") is not yet present, but
I'm naming the DT node in anticipation that it will be added.
Shouldn't the selection be done using an alias like this?
aliases {
serial0 = &/uart at 20201000;
};
Arnd
From: Stephen Warren <hidden> Date: 2012-09-13 01:15:55
On 09/12/2012 04:45 AM, Arnd Bergmann wrote:
On Wednesday 12 September 2012, Stephen Warren wrote:
quoted
From: Simon Arlott <redacted>
This patch was extracted from git://github.com/lp0/linux.git branch
rpi-split as of 2012/09/08, and modified as follows:
* Modified UART DT node to use a unit-address to differentiate UART node
names, rather than using different base names "uart0" and "uart1".
Note that UART 1 (the Broadcom "mini UART") is not yet present, but
I'm naming the DT node in anticipation that it will be added.
Shouldn't the selection be done using an alias like this?
aliases {
serial0 = &/uart at 20201000;
};
The "differentiate" was more "ensure that node names in DT are unique"
than anything to do with user-visible selection/identification.
I can certainly add the alias if you want, but I don't know what benefit
it will have, since I've never used aliases before.
On Thursday 13 September 2012, Stephen Warren wrote:
On 09/12/2012 04:45 AM, Arnd Bergmann wrote:
quoted
On Wednesday 12 September 2012, Stephen Warren wrote:
quoted
From: Simon Arlott <redacted>
This patch was extracted from git://github.com/lp0/linux.git branch
rpi-split as of 2012/09/08, and modified as follows:
* Modified UART DT node to use a unit-address to differentiate UART node
names, rather than using different base names "uart0" and "uart1".
Note that UART 1 (the Broadcom "mini UART") is not yet present, but
I'm naming the DT node in anticipation that it will be added.
Shouldn't the selection be done using an alias like this?
aliases {
serial0 = &/uart at 20201000;
};
The "differentiate" was more "ensure that node names in DT are unique"
than anything to do with user-visible selection/identification.
I can certainly add the alias if you want, but I don't know what benefit
it will have, since I've never used aliases before.
The idea of the aliases is that you can identify which port to use
if one passes an argument like "console=ttyS0" or opens a specific
/dev/tty* device node. I believe we don't actually use it that way
at the moment though.
Arnd
On Wednesday 12 September 2012, Stephen Warren wrote:
From: Simon Arlott <redacted>
The BCM2708 is an ARM SoC from Broadcom. It is the primary SoC in a
series which contains the BCM2835 amongst other variants. This patch
adds very basic support for this series of SoCs, under the BCM2708 name.
http://www.broadcom.com/products/BCM2835http://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripherals.pd
Note that the documentation in the latter .pdf assumes the MMU setup
that's used on the "VideoCore" companion processor, and does not document
physical peripheral addresses. Subtract 0x5e000000 to obtain the physical
addresses.
The BCM2835 SoC is used in the Raspberry Pi. This patch also adds a
minimal device tree for this board; enough to see some very early kernel
boot messages through earlyprintk. However, this patch does not yet
provide a useful booting system.
http://www.raspberrypi.org/.
This patch was extracted from git://github.com/lp0/linux.git branch
rpi-split from 3-4 months ago, and significantly stripped down and
modified since.
Signed-off-by: Chris Boot <bootc@bootc.net>
Signed-off-by: Simon Arlott <redacted>
Signed-off-by: Dom Cobley <redacted>
Signed-off-by: Dom Cobley <redacted>
Signed-off-by: Stephen Warren <redacted>
@@ -0,0 +1,15 @@+Broadcom BCM2708 device tree bindings+-------------------------------------------++Boards with the BCM2708 SoC, or another SoC in the BCM2708 family, shall have+the following properties:++Required root node property:++compatible = "broadcom,bcm2708";++Boards with BCM2835 SoC shall *additionally* have the following properties:++Required root node property:++compatible = "broadcom,bcm2835";
Please update also the vendor prefixes index at
Documentation/devicetree/bindings/vendor-prefixes.txt.
BTW is it possible to change it to "bcm"?
Regards,
Domenico
-----[ Domenico Andreoli, aka cavok
--[ http://cavokz.wordpress.com/gpgkey/
---[ 3A0F 2F80 F79C 678A 8936 4FEE 0677 9033 A20E BC50
@@ -0,0 +1,15 @@+Broadcom BCM2708 device tree bindings+-------------------------------------------++Boards with the BCM2708 SoC, or another SoC in the BCM2708 family, shall have+the following properties:++Required root node property:++compatible = "broadcom,bcm2708";++Boards with BCM2835 SoC shall *additionally* have the following properties:++Required root node property:++compatible = "broadcom,bcm2835";
Please update also the vendor prefixes index at
Documentation/devicetree/bindings/vendor-prefixes.txt.
Oops, yes, I forgot that.
BTW is it possible to change it to "bcm"?
I believe standard practice is to use the stock ticker symbol if not
using the full company name, so that'd be "brcm". Does anyone have an
objection? I'll assume not and make the change...
From: Olof Johansson <hidden> Date: 2012-09-16 00:34:50
On Thu, Sep 13, 2012 at 08:16:34PM -0600, Stephen Warren wrote:
quoted
BTW is it possible to change it to "bcm"?
I believe standard practice is to use the stock ticker symbol if not
using the full company name, so that'd be "brcm". Does anyone have an
objection? I'll assume not and make the change...
Yeah, "brcm," is the appropriate prefix in this case.
-Olof