This SoC is used in the Raspberry Pi, for example.
For more details, see: http://www.broadcom.com/products/BCM2835 http://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripheral....
Initial support is enough to boot to a serial console, execute a minimal set of U-Boot commands, download data over a serial port, and boot a Linux kernel. No storage or network drivers are implemented.
GPIO driver originally by Vikram Narayanan vikram186@gmail.com with many fixes from myself.
Signed-off-by: Stephen Warren swarren@wwwdotorg.org --- v3: Squash base SoC, watchdog, and GPIO driver patches into one. --- arch/arm/cpu/arm1176/bcm2835/Makefile | 37 +++++++++++ arch/arm/cpu/arm1176/bcm2835/config.mk | 19 ++++++ arch/arm/cpu/arm1176/bcm2835/lowlevel_init.S | 19 ++++++ arch/arm/cpu/arm1176/bcm2835/reset.c | 35 ++++++++++ arch/arm/cpu/arm1176/bcm2835/timer.c | 55 ++++++++++++++++ arch/arm/include/asm/arch-bcm2835/gpio.h | 66 +++++++++++++++++++ arch/arm/include/asm/arch-bcm2835/timer.h | 37 +++++++++++ arch/arm/include/asm/arch-bcm2835/wdog.h | 37 +++++++++++ drivers/gpio/Makefile | 1 + drivers/gpio/bcm2835_gpio.c | 90 ++++++++++++++++++++++++++ 10 files changed, 396 insertions(+) create mode 100644 arch/arm/cpu/arm1176/bcm2835/Makefile create mode 100644 arch/arm/cpu/arm1176/bcm2835/config.mk create mode 100644 arch/arm/cpu/arm1176/bcm2835/lowlevel_init.S create mode 100644 arch/arm/cpu/arm1176/bcm2835/reset.c create mode 100644 arch/arm/cpu/arm1176/bcm2835/timer.c create mode 100644 arch/arm/include/asm/arch-bcm2835/gpio.h create mode 100644 arch/arm/include/asm/arch-bcm2835/timer.h create mode 100644 arch/arm/include/asm/arch-bcm2835/wdog.h create mode 100644 drivers/gpio/bcm2835_gpio.c
diff --git a/arch/arm/cpu/arm1176/bcm2835/Makefile b/arch/arm/cpu/arm1176/bcm2835/Makefile new file mode 100644 index 0000000..4ea6d6b --- /dev/null +++ b/arch/arm/cpu/arm1176/bcm2835/Makefile @@ -0,0 +1,37 @@ +# +# 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. +# + +include $(TOPDIR)/config.mk + +LIB = $(obj)lib$(SOC).o + +SOBJS := lowlevel_init.o +COBJS := reset.o timer.o + +SRCS := $(SOBJS:.o=.c) $(COBJS:.o=.c) +OBJS := $(addprefix $(obj),$(SOBJS) $(COBJS)) + +all: $(obj).depend $(LIB) + +$(LIB): $(OBJS) + $(call cmd_link_o_target, $(OBJS)) + +######################################################################### + +# defines $(obj).depend target +include $(SRCTREE)/rules.mk + +sinclude $(obj).depend + +######################################################################### diff --git a/arch/arm/cpu/arm1176/bcm2835/config.mk b/arch/arm/cpu/arm1176/bcm2835/config.mk new file mode 100644 index 0000000..b87ce24 --- /dev/null +++ b/arch/arm/cpu/arm1176/bcm2835/config.mk @@ -0,0 +1,19 @@ +# +# (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. + +# Don't attempt to override the target CPU/ABI options; +# the Raspberry Pi toolchain does the right thing by default. +PLATFORM_RELFLAGS := $(filter-out -msoft-float,$(PLATFORM_RELFLAGS)) +PLATFORM_CPPFLAGS := $(filter-out -march=armv5t,$(PLATFORM_CPPFLAGS)) diff --git a/arch/arm/cpu/arm1176/bcm2835/lowlevel_init.S b/arch/arm/cpu/arm1176/bcm2835/lowlevel_init.S new file mode 100644 index 0000000..c7b0843 --- /dev/null +++ b/arch/arm/cpu/arm1176/bcm2835/lowlevel_init.S @@ -0,0 +1,19 @@ +/* + * (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. + */ + +.globl lowlevel_init +lowlevel_init: + mov pc, lr diff --git a/arch/arm/cpu/arm1176/bcm2835/reset.c b/arch/arm/cpu/arm1176/bcm2835/reset.c new file mode 100644 index 0000000..8c37ad9 --- /dev/null +++ b/arch/arm/cpu/arm1176/bcm2835/reset.c @@ -0,0 +1,35 @@ +/* + * (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. + */ + +#include <common.h> +#include <asm/io.h> +#include <asm/arch/wdog.h> + +#define RESET_TIMEOUT 10 + +void reset_cpu(ulong addr) +{ + struct bcm2835_wdog_regs *regs = + (struct bcm2835_wdog_regs *)BCM2835_WDOG_PHYSADDR; + uint32_t rstc; + + rstc = readl(®s->rstc); + rstc &= ~BCM2835_WDOG_RSTC_WRCFG_MASK; + rstc |= BCM2835_WDOG_RSTC_WRCFG_FULL_RESET; + + writel(BCM2835_WDOG_PASSWORD | RESET_TIMEOUT, ®s->wdog); + writel(BCM2835_WDOG_PASSWORD | rstc, ®s->rstc); +} diff --git a/arch/arm/cpu/arm1176/bcm2835/timer.c b/arch/arm/cpu/arm1176/bcm2835/timer.c new file mode 100644 index 0000000..d232d7e --- /dev/null +++ b/arch/arm/cpu/arm1176/bcm2835/timer.c @@ -0,0 +1,55 @@ +/* + * (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. + */ + +#include <common.h> +#include <asm/io.h> +#include <asm/arch/timer.h> + +int timer_init(void) +{ + return 0; +} + +ulong get_timer(ulong base) +{ + struct bcm2835_timer_regs *regs = + (struct bcm2835_timer_regs *)BCM2835_TIMER_PHYSADDR; + + return readl(®s->clo) - base; +} + +unsigned long long get_ticks(void) +{ + return get_timer(0); +} + +ulong get_tbclk(void) +{ + return CONFIG_SYS_HZ; +} + +void __udelay(unsigned long usec) +{ + ulong endtime; + signed long diff; + + endtime = get_timer(0) + usec; + + do { + ulong now = get_timer(0); + diff = endtime - now; + } while (diff >= 0); +} diff --git a/arch/arm/include/asm/arch-bcm2835/gpio.h b/arch/arm/include/asm/arch-bcm2835/gpio.h new file mode 100644 index 0000000..0e70856 --- /dev/null +++ b/arch/arm/include/asm/arch-bcm2835/gpio.h @@ -0,0 +1,66 @@ +/* + * Copyright (C) 2012 Vikram Narayananan + * vikram186@gmail.com + * + * 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 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_GPIO_H_ +#define _BCM2835_GPIO_H_ + +#define BCM2835_GPIO_BASE 0x20200000 +#define BCM2835_GPIO_COUNT 54 + +#define BCM2835_GPIO_FSEL_MASK 0x7 +#define BCM2835_GPIO_INPUT 0x0 +#define BCM2835_GPIO_OUTPUT 0x1 +#define BCM2835_GPIO_ALT0 0x4 +#define BCM2835_GPIO_ALT1 0x5 +#define BCM2835_GPIO_ALT2 0x6 +#define BCM2835_GPIO_ALT3 0x7 +#define BCM2835_GPIO_ALT4 0x3 +#define BCM2835_GPIO_ALT5 0x2 + +#define BCM2835_GPIO_COMMON_BANK(gpio) ((gpio < 32) ? 0 : 1) +#define BCM2835_GPIO_COMMON_SHIFT(gpio) (gpio & 0x1f) + +#define BCM2835_GPIO_FSEL_BANK(gpio) (gpio / 10) +#define BCM2835_GPIO_FSEL_SHIFT(gpio) ((gpio % 10) * 3) + +struct bcm2835_gpio_regs { + u32 gpfsel[6]; + u32 reserved1; + u32 gpset[2]; + u32 reserved2; + u32 gpclr[2]; + u32 reserved3; + u32 gplev[2]; + u32 reserved4; + u32 gpeds[2]; + u32 reserved5; + u32 gpren[2]; + u32 reserved6; + u32 gpfen[2]; + u32 reserved7; + u32 gphen[2]; + u32 reserved8; + u32 gplen[2]; + u32 reserved9; + u32 gparen[2]; + u32 reserved10; + u32 gppud; + u32 gppudclk[2]; +}; + +#endif /* _BCM2835_GPIO_H_ */ diff --git a/arch/arm/include/asm/arch-bcm2835/timer.h b/arch/arm/include/asm/arch-bcm2835/timer.h new file mode 100644 index 0000000..30c70e0 --- /dev/null +++ b/arch/arm/include/asm/arch-bcm2835/timer.h @@ -0,0 +1,37 @@ +/* + * (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_TIMER_H +#define _BCM2835_TIMER_H + +#define BCM2835_TIMER_PHYSADDR 0x20003000 + +struct bcm2835_timer_regs { + u32 cs; + u32 clo; + u32 chi; + u32 c0; + u32 c1; + u32 c2; + u32 c3; +}; + +#define BCM2835_TIMER_CS_M3 (1 << 3) +#define BCM2835_TIMER_CS_M2 (1 << 2) +#define BCM2835_TIMER_CS_M1 (1 << 1) +#define BCM2835_TIMER_CS_M0 (1 << 0) + +#endif diff --git a/arch/arm/include/asm/arch-bcm2835/wdog.h b/arch/arm/include/asm/arch-bcm2835/wdog.h new file mode 100644 index 0000000..d750a62 --- /dev/null +++ b/arch/arm/include/asm/arch-bcm2835/wdog.h @@ -0,0 +1,37 @@ +/* + * (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_TIMER_H +#define _BCM2835_TIMER_H + +#define BCM2835_WDOG_PHYSADDR 0x20100000 + +struct bcm2835_wdog_regs { + u32 unknown0[7]; + u32 rstc; + u32 unknown1; + u32 wdog; +}; + +#define BCM2835_WDOG_PASSWORD 0x5a000000 + +#define BCM2835_WDOG_RSTC_WRCFG_MASK 0x00000030 +#define BCM2835_WDOG_RSTC_WRCFG_FULL_RESET 0x00000020 + +#define BCM2835_WDOG_WDOG_TIMEOUT_MASK 0x0000ffff + +#endif + diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 32a2474..8d2f2b2 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -40,6 +40,7 @@ COBJS-$(CONFIG_TEGRA_GPIO) += tegra_gpio.o COBJS-$(CONFIG_DA8XX_GPIO) += da8xx_gpio.o COBJS-$(CONFIG_ALTERA_PIO) += altera_pio.o COBJS-$(CONFIG_MPC83XX_GPIO) += mpc83xx_gpio.o +COBJS-$(CONFIG_BCM2835_GPIO) += bcm2835_gpio.o
COBJS := $(COBJS-y) SRCS := $(COBJS:.o=.c) diff --git a/drivers/gpio/bcm2835_gpio.c b/drivers/gpio/bcm2835_gpio.c new file mode 100644 index 0000000..6ab2df3 --- /dev/null +++ b/drivers/gpio/bcm2835_gpio.c @@ -0,0 +1,90 @@ +/* + * Copyright (C) 2012 Vikram Narayananan + * vikram186@gmail.com + * + * 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 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 <common.h> +#include <asm/gpio.h> +#include <asm/io.h> + +inline int gpio_is_valid(unsigned gpio) +{ + return (gpio < BCM2835_GPIO_COUNT); +} + +int gpio_request(unsigned gpio, const char *label) +{ + return !gpio_is_valid(gpio); +} + +int gpio_free(unsigned gpio) +{ + return 0; +} + +int gpio_direction_input(unsigned gpio) +{ + struct bcm2835_gpio_regs *reg = + (struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE; + unsigned val; + + val = readl(®->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]); + val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio)); + val |= (BCM2835_GPIO_INPUT << BCM2835_GPIO_FSEL_SHIFT(gpio)); + writel(val, ®->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]); + + return 0; +} + +int gpio_direction_output(unsigned gpio, int value) +{ + struct bcm2835_gpio_regs *reg = + (struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE; + unsigned val; + + gpio_set_value(gpio, value); + + val = readl(®->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]); + val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio)); + val |= (BCM2835_GPIO_OUTPUT << BCM2835_GPIO_FSEL_SHIFT(gpio)); + writel(val, ®->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]); + + return 0; +} + +int gpio_get_value(unsigned gpio) +{ + struct bcm2835_gpio_regs *reg = + (struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE; + unsigned val; + + val = readl(®->gplev[BCM2835_GPIO_COMMON_BANK(gpio)]); + + return (val >> BCM2835_GPIO_COMMON_SHIFT(gpio)) & 0x1; +} + +int gpio_set_value(unsigned gpio, int value) +{ + struct bcm2835_gpio_regs *reg = + (struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE; + u32 *output_reg = value ? reg->gpset : reg->gpclr; + + writel(1 << BCM2835_GPIO_COMMON_SHIFT(gpio), + &output_reg[BCM2835_GPIO_COMMON_BANK(gpio)]); + + return 0; +} +