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/mach-bcm2835/bcm2835.c | 77 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 77 insertions(+) create mode 100644 arch/arm/mach-bcm2835/bcm2835.c (limited to 'arch/arm/mach-bcm2835/bcm2835.c') diff --git a/arch/arm/mach-bcm2835/bcm2835.c b/arch/arm/mach-bcm2835/bcm2835.c new file mode 100644 index 00000000000..f6b36b4b592 --- /dev/null +++ b/arch/arm/mach-bcm2835/bcm2835.c @@ -0,0 +1,77 @@ +/* + * Copyright (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 as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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. + */ + +#include +#include + +#include +#include +#include +#include + +#include + +static struct map_desc io_map __initdata = { + .virtual = BCM2835_PERIPH_VIRT, + .pfn = __phys_to_pfn(BCM2835_PERIPH_PHYS), + .length = BCM2835_PERIPH_SIZE, + .type = MT_DEVICE +}; + +void __init bcm2835_map_io(void) +{ + iotable_init(&io_map, 1); +} + +void __init bcm2835_init_irq(void) +{ +} + +asmlinkage void __exception_irq_entry bcm2835_handle_irq(struct pt_regs *regs) +{ +} + +void __init bcm2835_init(void) +{ + int ret; + + ret = of_platform_populate(NULL, of_default_bus_match_table, NULL, + NULL); + if (ret) { + pr_err("of_platform_populate failed: %d\n", ret); + BUG(); + } +} + +static void __init bcm2835_timer_init(void) +{ +} + +struct sys_timer bcm2835_timer = { + .init = bcm2835_timer_init +}; + +static const char * const bcm2835_compat[] = { + "brcm,bcm2835", + NULL +}; + +DT_MACHINE_START(BCM2835, "BCM2835") + .map_io = bcm2835_map_io, + .init_irq = bcm2835_init_irq, + .handle_irq = bcm2835_handle_irq, + .init_machine = bcm2835_init, + .timer = &bcm2835_timer, + .dt_compat = bcm2835_compat +MACHINE_END -- cgit v1.2.3-70-g09d2 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 --- .../brcm,bcm2835-armctrl-ic.txt | 110 ++++++++++ arch/arm/boot/dts/bcm2835.dtsi | 8 + arch/arm/mach-bcm2835/bcm2835.c | 10 +- drivers/Kconfig | 2 + drivers/Makefile | 2 + drivers/irqchip/Kconfig | 0 drivers/irqchip/Makefile | 1 + drivers/irqchip/irq-bcm2835.c | 223 +++++++++++++++++++++ include/linux/irqchip/bcm2835.h | 29 +++ 9 files changed, 376 insertions(+), 9 deletions(-) create mode 100644 Documentation/devicetree/bindings/interrupt-controller/brcm,bcm2835-armctrl-ic.txt create mode 100644 drivers/irqchip/Kconfig create mode 100644 drivers/irqchip/Makefile create mode 100644 drivers/irqchip/irq-bcm2835.c create mode 100644 include/linux/irqchip/bcm2835.h (limited to 'arch/arm/mach-bcm2835/bcm2835.c') diff --git a/Documentation/devicetree/bindings/interrupt-controller/brcm,bcm2835-armctrl-ic.txt b/Documentation/devicetree/bindings/interrupt-controller/brcm,bcm2835-armctrl-ic.txt new file mode 100644 index 00000000000..548892c08c5 --- /dev/null +++ b/Documentation/devicetree/bindings/interrupt-controller/brcm,bcm2835-armctrl-ic.txt @@ -0,0 +1,110 @@ +BCM2835 Top-Level ("ARMCTRL") Interrupt Controller + +The BCM2835 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 "brcm,bcm2835-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: + +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 = "brcm,bcm2835-armctrl-ic"; + reg = <0x7e00b200 0x200>; + interrupt-controller; + #interrupt-cells = <2>; +}; diff --git a/arch/arm/boot/dts/bcm2835.dtsi b/arch/arm/boot/dts/bcm2835.dtsi index a31cb40ef68..8842d751d7d 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>; + }; }; }; diff --git a/arch/arm/mach-bcm2835/bcm2835.c b/arch/arm/mach-bcm2835/bcm2835.c index f6b36b4b592..72c4b5ff8f9 100644 --- a/arch/arm/mach-bcm2835/bcm2835.c +++ b/arch/arm/mach-bcm2835/bcm2835.c @@ -13,12 +13,12 @@ */ #include +#include #include #include #include #include -#include #include @@ -34,14 +34,6 @@ void __init bcm2835_map_io(void) iotable_init(&io_map, 1); } -void __init bcm2835_init_irq(void) -{ -} - -asmlinkage void __exception_irq_entry bcm2835_handle_irq(struct pt_regs *regs) -{ -} - void __init bcm2835_init(void) { int ret; diff --git a/drivers/Kconfig b/drivers/Kconfig index ece958d3762..36d3daa19a7 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -152,4 +152,6 @@ source "drivers/vme/Kconfig" source "drivers/pwm/Kconfig" +source "drivers/irqchip/Kconfig" + endmenu diff --git a/drivers/Makefile b/drivers/Makefile index 5b421840c48..8c30e73cd94 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -5,6 +5,8 @@ # Rewritten to use lists instead of if-statements. # +obj-y += irqchip/ + # GPIO must come after pinctrl as gpios may need to mux pins etc obj-y += pinctrl/ obj-y += gpio/ diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig new file mode 100644 index 00000000000..e69de29bb2d diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile new file mode 100644 index 00000000000..054321db435 --- /dev/null +++ b/drivers/irqchip/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_ARCH_BCM2835) += irq-bcm2835.o diff --git a/drivers/irqchip/irq-bcm2835.c b/drivers/irqchip/irq-bcm2835.c new file mode 100644 index 00000000000..dc670ccc697 --- /dev/null +++ b/drivers/irqchip/irq-bcm2835.c @@ -0,0 +1,223 @@ +/* + * Copyright 2010 Broadcom + * Copyright 2012 Simon Arlott, Chris Boot, Stephen Warren + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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. + * + * Quirk 1: Shortcut interrupts don't set the bank 1/2 register pending bits + * + * If an interrupt fires on bank 1 that isn't in the shortcuts list, bit 8 + * on bank 0 is set to signify that an interrupt in bank 1 has fired, and + * to look in the bank 1 status register for more information. + * + * If an interrupt fires on bank 1 that _is_ in the shortcuts list, its + * shortcut bit in bank 0 is set as well as its interrupt bit in the bank 1 + * status register, but bank 0 bit 8 is _not_ set. + * + * Quirk 2: You can't mask the register 1/2 pending interrupts + * + * In a proper cascaded interrupt controller, the interrupt lines with + * cascaded interrupt controllers on them are just normal interrupt lines. + * You can mask the interrupts and get on with things. With this controller + * you can't do that. + * + * Quirk 3: The shortcut interrupts can't be (un)masked in bank 0 + * + * Those interrupts that have shortcuts can only be masked/unmasked in + * their respective banks' enable/disable registers. Doing so in the bank 0 + * enable/disable registers has no effect. + * + * The FIQ control register: + * Bits 0-6: IRQ (index in order of interrupts from banks 1, 2, then 0) + * Bit 7: Enable FIQ generation + * Bits 8+: Unused + * + * An interrupt must be disabled before configuring it for FIQ generation + * otherwise both handlers will fire at the same time! + */ + +#include +#include +#include +#include +#include +#include + +#include + +/* 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 + +static int reg_pending[] __initconst = { 0x00, 0x04, 0x08 }; +static int reg_enable[] __initconst = { 0x18, 0x10, 0x14 }; +static int reg_disable[] __initconst = { 0x24, 0x1c, 0x20 }; +static int bank_irqs[] __initconst = { 8, 32, 32 }; + +static const int shortcuts[] = { + 7, 9, 10, 18, 19, /* Bank 1 */ + 21, 22, 23, 24, 25, 30 /* Bank 2 */ +}; + +struct armctrl_ic { + void __iomem *base; + void __iomem *pending[NR_BANKS]; + void __iomem *enable[NR_BANKS]; + void __iomem *disable[NR_BANKS]; + struct irq_domain *domain; +}; + +static struct armctrl_ic intc __read_mostly; + +static void armctrl_mask_irq(struct irq_data *d) +{ + writel_relaxed(HWIRQ_BIT(d->hwirq), intc.disable[HWIRQ_BANK(d->hwirq)]); +} + +static void armctrl_unmask_irq(struct irq_data *d) +{ + writel_relaxed(HWIRQ_BIT(d->hwirq), intc.enable[HWIRQ_BANK(d->hwirq)]); +} + +static struct irq_chip armctrl_chip = { + .name = "ARMCTRL-level", + .irq_mask = armctrl_mask_irq, + .irq_unmask = armctrl_unmask_irq +}; + +static int armctrl_xlate(struct irq_domain *d, struct device_node *ctrlr, + const u32 *intspec, unsigned int intsize, + unsigned long *out_hwirq, unsigned int *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; + return 0; +} + +static struct irq_domain_ops armctrl_ops = { + .xlate = armctrl_xlate +}; + +static int __init armctrl_of_init(struct device_node *node, + struct device_node *parent) +{ + void __iomem *base; + int irq, b, i; + + base = of_iomap(node, 0); + if (!base) + panic("%s: unable to map 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); + } + } + return 0; +} + +static struct of_device_id irq_of_match[] __initconst = { + { .compatible = "brcm,bcm2835-armctrl-ic", .data = armctrl_of_init } +}; + +void __init bcm2835_init_irq(void) +{ + of_irq_init(irq_of_match); +} + +/* + * Handle each interrupt across the entire interrupt controller. This reads the + * status register before handling each interrupt, which is necessary given that + * handle_IRQ may briefly re-enable interrupts for soft IRQ handling. + */ + +static void armctrl_handle_bank(int bank, struct pt_regs *regs) +{ + u32 stat, irq; + + while ((stat = readl_relaxed(intc.pending[bank]))) { + irq = MAKE_HWIRQ(bank, ffs(stat) - 1); + handle_IRQ(irq_linear_revmap(intc.domain, irq), regs); + } +} + +static void armctrl_handle_shortcut(int bank, struct pt_regs *regs, + u32 stat) +{ + u32 irq = MAKE_HWIRQ(bank, shortcuts[ffs(stat >> SHORTCUT_SHIFT) - 1]); + handle_IRQ(irq_linear_revmap(intc.domain, irq), regs); +} + +asmlinkage void __exception_irq_entry bcm2835_handle_irq( + struct pt_regs *regs) +{ + u32 stat, 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); + } else if (stat & SHORTCUT1_MASK) { + armctrl_handle_shortcut(1, regs, stat & SHORTCUT1_MASK); + } else if (stat & SHORTCUT2_MASK) { + armctrl_handle_shortcut(2, regs, stat & SHORTCUT2_MASK); + } else if (stat & BANK1_HWIRQ) { + armctrl_handle_bank(1, regs); + } else if (stat & BANK2_HWIRQ) { + armctrl_handle_bank(2, regs); + } else { + BUG(); + } + } +} diff --git a/include/linux/irqchip/bcm2835.h b/include/linux/irqchip/bcm2835.h new file mode 100644 index 00000000000..48a859bc9dc --- /dev/null +++ b/include/linux/irqchip/bcm2835.h @@ -0,0 +1,29 @@ +/* + * Copyright (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 as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#ifndef __LINUX_IRQCHIP_BCM2835_H_ +#define __LINUX_IRQCHIP_BCM2835_H_ + +#include + +extern void bcm2835_init_irq(void); + +extern asmlinkage void __exception_irq_entry bcm2835_handle_irq( + struct pt_regs *regs); + +#endif -- cgit v1.2.3-70-g09d2 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 --- .../bindings/timer/brcm,bcm2835-system-timer.txt | 22 +++ arch/arm/boot/dts/bcm2835.dtsi | 7 + arch/arm/mach-bcm2835/bcm2835.c | 10 +- drivers/clocksource/Makefile | 1 + drivers/clocksource/bcm2835_timer.c | 161 +++++++++++++++++++++ include/linux/bcm2835_timer.h | 22 +++ 6 files changed, 214 insertions(+), 9 deletions(-) create mode 100644 Documentation/devicetree/bindings/timer/brcm,bcm2835-system-timer.txt create mode 100644 drivers/clocksource/bcm2835_timer.c create mode 100644 include/linux/bcm2835_timer.h (limited to 'arch/arm/mach-bcm2835/bcm2835.c') diff --git a/Documentation/devicetree/bindings/timer/brcm,bcm2835-system-timer.txt b/Documentation/devicetree/bindings/timer/brcm,bcm2835-system-timer.txt new file mode 100644 index 00000000000..2de21c2acf5 --- /dev/null +++ b/Documentation/devicetree/bindings/timer/brcm,bcm2835-system-timer.txt @@ -0,0 +1,22 @@ +BCM2835 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 "brcm,bcm2835-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 = "brcm,bcm2835-system-timer"; + reg = <0x7e003000 0x1000>; + interrupts = <1 0>, <1 1>, <1 2>, <1 3>; + clock-frequency = <1000000>; +}; diff --git a/arch/arm/boot/dts/bcm2835.dtsi b/arch/arm/boot/dts/bcm2835.dtsi index 8842d751d7d..e7471d271e0 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>; diff --git a/arch/arm/mach-bcm2835/bcm2835.c b/arch/arm/mach-bcm2835/bcm2835.c index 72c4b5ff8f9..e3f296860dd 100644 --- a/arch/arm/mach-bcm2835/bcm2835.c +++ b/arch/arm/mach-bcm2835/bcm2835.c @@ -15,10 +15,10 @@ #include #include #include +#include #include #include -#include #include @@ -46,14 +46,6 @@ void __init bcm2835_init(void) } } -static void __init bcm2835_timer_init(void) -{ -} - -struct sys_timer bcm2835_timer = { - .init = bcm2835_timer_init -}; - static const char * const bcm2835_compat[] = { "brcm,bcm2835", NULL diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index b65d0c56ab3..d496a55f6bb 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -13,3 +13,4 @@ obj-$(CONFIG_DW_APB_TIMER) += dw_apb_timer.o obj-$(CONFIG_DW_APB_TIMER_OF) += dw_apb_timer_of.o obj-$(CONFIG_CLKSRC_DBX500_PRCMU) += clksrc-dbx500-prcmu.o obj-$(CONFIG_ARMADA_370_XP_TIMER) += time-armada-370-xp.o +obj-$(CONFIG_ARCH_BCM2835) += bcm2835_timer.o diff --git a/drivers/clocksource/bcm2835_timer.c b/drivers/clocksource/bcm2835_timer.c new file mode 100644 index 00000000000..bc19f12c20c --- /dev/null +++ b/drivers/clocksource/bcm2835_timer.c @@ -0,0 +1,161 @@ +/* + * Copyright 2012 Simon Arlott + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#define REG_CONTROL 0x00 +#define REG_COUNTER_LO 0x04 +#define REG_COUNTER_HI 0x08 +#define REG_COMPARE(n) (0x0c + (n) * 4) +#define MAX_TIMER 3 +#define DEFAULT_TIMER 3 + +struct bcm2835_timer { + void __iomem *control; + void __iomem *compare; + int match_mask; + struct clock_event_device evt; + struct irqaction act; +}; + +static void __iomem *system_clock __read_mostly; + +static u32 notrace bcm2835_sched_read(void) +{ + return readl_relaxed(system_clock); +} + +static void bcm2835_time_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt_dev) +{ + switch (mode) { + case CLOCK_EVT_MODE_ONESHOT: + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_RESUME: + break; + default: + WARN(1, "%s: unhandled event mode %d\n", __func__, mode); + break; + } +} + +static int bcm2835_time_set_next_event(unsigned long event, + struct clock_event_device *evt_dev) +{ + struct bcm2835_timer *timer = container_of(evt_dev, + struct bcm2835_timer, evt); + writel_relaxed(readl_relaxed(system_clock) + event, + timer->compare); + return 0; +} + +static irqreturn_t bcm2835_time_interrupt(int irq, void *dev_id) +{ + struct bcm2835_timer *timer = dev_id; + void (*event_handler)(struct clock_event_device *); + if (readl_relaxed(timer->control) & timer->match_mask) { + writel_relaxed(timer->match_mask, timer->control); + + event_handler = ACCESS_ONCE(timer->evt.event_handler); + if (event_handler) + event_handler(&timer->evt); + return IRQ_HANDLED; + } else { + return IRQ_NONE; + } +} + +static struct of_device_id bcm2835_time_match[] __initconst = { + { .compatible = "brcm,bcm2835-system-timer" }, + {} +}; + +static void __init bcm2835_time_init(void) +{ + struct device_node *node; + void __iomem *base; + u32 freq; + int irq; + struct bcm2835_timer *timer; + + node = of_find_matching_node(NULL, bcm2835_time_match); + if (!node) + panic("No bcm2835 timer node"); + + base = of_iomap(node, 0); + if (!base) + panic("Can't remap registers"); + + if (of_property_read_u32(node, "clock-frequency", &freq)) + panic("Can't read clock-frequency"); + + system_clock = base + REG_COUNTER_LO; + setup_sched_clock(bcm2835_sched_read, 32, freq); + + clocksource_mmio_init(base + REG_COUNTER_LO, node->name, + freq, 300, 32, clocksource_mmio_readl_up); + + irq = irq_of_parse_and_map(node, DEFAULT_TIMER); + if (irq <= 0) + panic("Can't parse IRQ"); + + timer = kzalloc(sizeof(*timer), GFP_KERNEL); + if (!timer) + panic("Can't allocate timer struct\n"); + + timer->control = base + REG_CONTROL; + timer->compare = base + REG_COMPARE(DEFAULT_TIMER); + timer->match_mask = BIT(DEFAULT_TIMER); + timer->evt.name = node->name; + timer->evt.rating = 300; + timer->evt.features = CLOCK_EVT_FEAT_ONESHOT; + timer->evt.set_mode = bcm2835_time_set_mode; + timer->evt.set_next_event = bcm2835_time_set_next_event; + timer->evt.cpumask = cpumask_of(0); + timer->act.name = node->name; + timer->act.flags = IRQF_TIMER | IRQF_SHARED; + timer->act.dev_id = timer; + timer->act.handler = bcm2835_time_interrupt; + + if (setup_irq(irq, &timer->act)) + panic("Can't set up timer IRQ\n"); + + clockevents_config_and_register(&timer->evt, freq, 0xf, 0xffffffff); + + pr_info("bcm2835: system timer (irq = %d)\n", irq); +} + +struct sys_timer bcm2835_timer = { + .init = bcm2835_time_init, +}; diff --git a/include/linux/bcm2835_timer.h b/include/linux/bcm2835_timer.h new file mode 100644 index 00000000000..25680fe0903 --- /dev/null +++ b/include/linux/bcm2835_timer.h @@ -0,0 +1,22 @@ +/* + * Copyright 2012 Simon Arlott + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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_TIMER_H +#define __BCM2835_TIMER_H + +#include + +extern struct sys_timer bcm2835_timer; + +#endif -- cgit v1.2.3-70-g09d2 From 75fabc3f64489aa2c52eec54cd433ea269a25e05 Mon Sep 17 00:00:00 2001 From: Simon Arlott Date: Mon, 10 Sep 2012 23:26:15 -0600 Subject: ARM: bcm2835: add stub clock driver This patch adds a minimal stub clock driver for the BCM2835. 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: * Reworked to call clk_register_fixed_rate(), and clk_register_clkdev() rather than using static data to represent the clocks. * Moved implementation to drivers/clk/. * Modified .dev_id for UART clocks to match UART DT node names. * s/bcm2708/bcm2835/. * Modified device tree vendor prefix. 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: Mike Turquette --- arch/arm/mach-bcm2835/bcm2835.c | 3 +++ drivers/clk/Makefile | 1 + drivers/clk/clk-bcm2835.c | 59 +++++++++++++++++++++++++++++++++++++++++ include/linux/clk/bcm2835.h | 24 +++++++++++++++++ 4 files changed, 87 insertions(+) create mode 100644 drivers/clk/clk-bcm2835.c create mode 100644 include/linux/clk/bcm2835.h (limited to 'arch/arm/mach-bcm2835/bcm2835.c') diff --git a/arch/arm/mach-bcm2835/bcm2835.c b/arch/arm/mach-bcm2835/bcm2835.c index e3f296860dd..f6fea493357 100644 --- a/arch/arm/mach-bcm2835/bcm2835.c +++ b/arch/arm/mach-bcm2835/bcm2835.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include @@ -38,6 +39,8 @@ void __init bcm2835_init(void) { int ret; + bcm2835_init_clocks(); + ret = of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL); if (ret) { diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index 5869ea38705..d5c19d1e0cf 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -3,6 +3,7 @@ obj-$(CONFIG_CLKDEV_LOOKUP) += clkdev.o obj-$(CONFIG_COMMON_CLK) += clk.o clk-fixed-rate.o clk-gate.o \ clk-mux.o clk-divider.o clk-fixed-factor.o # SoCs specific +obj-$(CONFIG_ARCH_BCM2835) += clk-bcm2835.o obj-$(CONFIG_ARCH_NOMADIK) += clk-nomadik.o obj-$(CONFIG_ARCH_HIGHBANK) += clk-highbank.o obj-$(CONFIG_ARCH_MXS) += mxs/ diff --git a/drivers/clk/clk-bcm2835.c b/drivers/clk/clk-bcm2835.c new file mode 100644 index 00000000000..67ad16b20b8 --- /dev/null +++ b/drivers/clk/clk-bcm2835.c @@ -0,0 +1,59 @@ +/* + * Copyright (C) 2010 Broadcom + * Copyright (C) 2012 Stephen Warren + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include +#include +#include + +/* + * These are fixed clocks. They're probably not all root clocks and it may + * be possible to turn them on and off but until this is mapped out better + * it's the only way they can be used. + */ +void __init bcm2835_init_clocks(void) +{ + struct clk *clk; + int ret; + + clk = clk_register_fixed_rate(NULL, "sys_pclk", NULL, CLK_IS_ROOT, + 250000000); + if (!clk) + pr_err("sys_pclk not registered\n"); + + clk = clk_register_fixed_rate(NULL, "apb_pclk", NULL, CLK_IS_ROOT, + 126000000); + if (!clk) + pr_err("apb_pclk not registered\n"); + + clk = clk_register_fixed_rate(NULL, "uart0_pclk", NULL, CLK_IS_ROOT, + 3000000); + if (!clk) + pr_err("uart0_pclk not registered\n"); + ret = clk_register_clkdev(clk, NULL, "20201000.uart"); + if (ret) + pr_err("uart0_pclk alias not registered\n"); + + clk = clk_register_fixed_rate(NULL, "uart1_pclk", NULL, CLK_IS_ROOT, + 125000000); + if (!clk) + pr_err("uart1_pclk not registered\n"); + ret = clk_register_clkdev(clk, NULL, "20215000.uart"); + if (ret) + pr_err("uart0_pclk alias not registered\n"); +} diff --git a/include/linux/clk/bcm2835.h b/include/linux/clk/bcm2835.h new file mode 100644 index 00000000000..aa937f6c17d --- /dev/null +++ b/include/linux/clk/bcm2835.h @@ -0,0 +1,24 @@ +/* + * Copyright (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 as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#ifndef __LINUX_CLK_BCM2835_H_ +#define __LINUX_CLK_BCM2835_H_ + +void __init bcm2835_init_clocks(void); + +#endif -- cgit v1.2.3-70-g09d2