From ec9653b8476bf526dde7bdefbc2be6b7aaa34db7 Mon Sep 17 00:00:00 2001 From: Simon Arlott Date: Sat, 26 May 2012 01:04:43 -0600 Subject: ARM: add infra-structure for BCM2835 and Raspberry Pi The BCM2835 is an ARM SoC from Broadcom. This patch adds very basic support for this SoC. http://www.broadcom.com/products/BCM2835 http://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripherals.pdf 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. This is accounted for by the ranges property in the /soc node in the device tree. 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 Signed-off-by: Simon Arlott Signed-off-by: Dom Cobley Signed-off-by: Dom Cobley Signed-off-by: Stephen Warren Acked-by: Arnd Bergmann --- arch/arm/boot/dts/bcm2835-rpi-b.dts | 12 ++++++++++++ arch/arm/boot/dts/bcm2835.dtsi | 17 +++++++++++++++++ 2 files changed, 29 insertions(+) create mode 100644 arch/arm/boot/dts/bcm2835-rpi-b.dts create mode 100644 arch/arm/boot/dts/bcm2835.dtsi (limited to 'arch/arm/boot') diff --git a/arch/arm/boot/dts/bcm2835-rpi-b.dts b/arch/arm/boot/dts/bcm2835-rpi-b.dts new file mode 100644 index 0000000..7dd860f --- /dev/null +++ b/arch/arm/boot/dts/bcm2835-rpi-b.dts @@ -0,0 +1,12 @@ +/dts-v1/; +/memreserve/ 0x0c000000 0x04000000; +/include/ "bcm2835.dtsi" + +/ { + compatible = "raspberrypi,model-b", "brcm,bcm2835"; + model = "Raspberry Pi Model B"; + + memory { + reg = <0 0x10000000>; + }; +}; diff --git a/arch/arm/boot/dts/bcm2835.dtsi b/arch/arm/boot/dts/bcm2835.dtsi new file mode 100644 index 0000000..a31cb40 --- /dev/null +++ b/arch/arm/boot/dts/bcm2835.dtsi @@ -0,0 +1,17 @@ +/include/ "skeleton.dtsi" + +/ { + compatible = "brcm,bcm2835"; + model = "BCM2835"; + + chosen { + bootargs = "earlyprintk"; + }; + + soc { + compatible = "simple-bus"; + #address-cells = <1>; + #size-cells = <1>; + ranges = <0x7e000000 0x20000000 0x02000000>; + }; +}; -- cgit v1.1 From 89214f009c1d38568456dcf997d93977928fe2c3 Mon Sep 17 00:00:00 2001 From: Simon Arlott Date: Wed, 12 Sep 2012 19:57:26 -0600 Subject: ARM: bcm2835: add interrupt controller driver The BCM2835 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: * s/bcm2708/bcm2835/. * Modified device tree vendor prefix. * Moved implementation to drivers/irchip/. * 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. * Simplified armctrl_of_init() using of_iomap(). * 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 Signed-off-by: Simon Arlott Signed-off-by: Dom Cobley Signed-off-by: Dom Cobley Signed-off-by: Stephen Warren Acked-by: Arnd Bergmann --- arch/arm/boot/dts/bcm2835.dtsi | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'arch/arm/boot') diff --git a/arch/arm/boot/dts/bcm2835.dtsi b/arch/arm/boot/dts/bcm2835.dtsi index a31cb40..8842d75 100644 --- a/arch/arm/boot/dts/bcm2835.dtsi +++ b/arch/arm/boot/dts/bcm2835.dtsi @@ -3,6 +3,7 @@ / { compatible = "brcm,bcm2835"; model = "BCM2835"; + interrupt-parent = <&intc>; chosen { bootargs = "earlyprintk"; @@ -13,5 +14,12 @@ #address-cells = <1>; #size-cells = <1>; ranges = <0x7e000000 0x20000000 0x02000000>; + + intc: interrupt-controller { + compatible = "brcm,bcm2835-armctrl-ic"; + reg = <0x7e00b200 0x200>; + interrupt-controller; + #interrupt-cells = <2>; + }; }; }; -- cgit v1.1 From ee4af5696720bb5b9de2e3b18be42089bed1e638 Mon Sep 17 00:00:00 2001 From: Simon Arlott Date: Mon, 10 Sep 2012 22:38:35 -0600 Subject: ARM: bcm2835: add 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. Timer 3 is used as the Linux timer. The BCM2835 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: * s/bcm2708/bcm2835/. * Modified device tree vendor prefix. * Moved to drivers/clocksource/. This looks like the desired location for such code now. * Added DT binding docs. * Moved struct sys_timer bcm2835_timer into time.c to encapsulate it more. * Simplified bcm2835_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. * Simplified bcm2835_time_init() using of_iomap(). * Renamed struct bcm2835_timer.index to match_mask to better represent its purpose. * s/printk(PR_INFO/pr_info(/ Signed-off-by: Chris Boot Signed-off-by: Simon Arlott Signed-off-by: Dom Cobley Signed-off-by: Dom Cobley Signed-off-by: Stephen Warren Acked-by: Arnd Bergmann --- arch/arm/boot/dts/bcm2835.dtsi | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'arch/arm/boot') diff --git a/arch/arm/boot/dts/bcm2835.dtsi b/arch/arm/boot/dts/bcm2835.dtsi index 8842d75..e7471d2 100644 --- a/arch/arm/boot/dts/bcm2835.dtsi +++ b/arch/arm/boot/dts/bcm2835.dtsi @@ -15,6 +15,13 @@ #size-cells = <1>; ranges = <0x7e000000 0x20000000 0x02000000>; + timer { + compatible = "brcm,bcm2835-system-timer"; + reg = <0x7e003000 0x1000>; + interrupts = <1 0>, <1 1>, <1 2>, <1 3>; + clock-frequency = <1000000>; + }; + intc: interrupt-controller { compatible = "brcm,bcm2835-armctrl-ic"; reg = <0x7e00b200 0x200>; -- cgit v1.1 From 407f9be4544538674fb83a2d064a25428595c7ff Mon Sep 17 00:00:00 2001 From: Simon Arlott Date: Mon, 10 Sep 2012 23:29:17 -0600 Subject: ARM: bcm2835: instantiate console UART This patch was extracted from git://github.com/lp0/linux.git branch rpi-split as of 2012/09/08, and modified as follows: * s/bcm2708/bcm2835/. * Modified device tree vendor prefix. * Modified UART DT node to use a unit-address to create unique UART node names, rather than using non-type 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 Signed-off-by: Simon Arlott Signed-off-by: Dom Cobley Signed-off-by: Dom Cobley Signed-off-by: Stephen Warren Acked-by: Arnd Bergmann --- arch/arm/boot/dts/bcm2835.dtsi | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'arch/arm/boot') diff --git a/arch/arm/boot/dts/bcm2835.dtsi b/arch/arm/boot/dts/bcm2835.dtsi index e7471d2..0b61939 100644 --- a/arch/arm/boot/dts/bcm2835.dtsi +++ b/arch/arm/boot/dts/bcm2835.dtsi @@ -6,7 +6,7 @@ interrupt-parent = <&intc>; chosen { - bootargs = "earlyprintk"; + bootargs = "earlyprintk console=ttyAMA0"; }; soc { @@ -28,5 +28,12 @@ interrupt-controller; #interrupt-cells = <2>; }; + + uart@20201000 { + compatible = "brcm,bcm2835-pl011", "arm,pl011", "arm,primecell"; + reg = <0x7e201000 0x1000>; + interrupts = <2 25>; + clock-frequency = <3000000>; + }; }; }; -- cgit v1.1