diff options
| -rw-r--r-- | arch/arc/include/asm/arcregs.h | 4 | ||||
| -rw-r--r-- | doc/device-tree-bindings/timer/arc_timer.txt | 24 | ||||
| -rw-r--r-- | drivers/timer/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/timer/Makefile | 1 | ||||
| -rw-r--r-- | drivers/timer/arc_timer.c | 113 |
5 files changed, 151 insertions, 0 deletions
diff --git a/arch/arc/include/asm/arcregs.h b/arch/arc/include/asm/arcregs.h index cf999b0..54a9b00 100644 --- a/arch/arc/include/asm/arcregs.h +++ b/arch/arc/include/asm/arcregs.h @@ -33,6 +33,10 @@ #define ARC_AUX_TIMER0_CTRL 0x22 /* Timer 0 control */ #define ARC_AUX_TIMER0_LIMIT 0x23 /* Timer 0 limit */ +#define ARC_AUX_TIMER1_CNT 0x100 /* Timer 1 count */ +#define ARC_AUX_TIMER1_CTRL 0x101 /* Timer 1 control */ +#define ARC_AUX_TIMER1_LIMIT 0x102 /* Timer 1 limit */ + #define ARC_AUX_INTR_VEC_BASE 0x25 /* Data cache related auxiliary registers */ diff --git a/doc/device-tree-bindings/timer/arc_timer.txt b/doc/device-tree-bindings/timer/arc_timer.txt new file mode 100644 index 0000000..5493b21 --- /dev/null +++ b/doc/device-tree-bindings/timer/arc_timer.txt @@ -0,0 +1,24 @@ +ARC Timer + +Required properties: + +- compatible : should be "snps,arc-timer". +- reg : Specifies timer ID, could be either 0 or 1. +- clocks : Specifies clocks that drives the counter. + +Examples: + +timer@0 { + compatible = "snps,arc-timer"; + clocks = <&core_clk>; + reg = <0>; +}; + +timer@1 { + compatible = "snps,arc-timer"; + clocks = <&core_clk>; + reg = <1>; +}; + +NOTE: if you specify both timers, clocks always should be the same +as each timer is driven by the same core clock. diff --git a/drivers/timer/Kconfig b/drivers/timer/Kconfig index 72c1416..e038523 100644 --- a/drivers/timer/Kconfig +++ b/drivers/timer/Kconfig @@ -65,4 +65,13 @@ config STI_TIMER help Select this to enable a timer for STi devices. +config ARC_TIMER + bool "ARC timer support" + depends on TIMER && ARC && CLK + help + Select this to enable built-in ARC timers. + ARC cores may have up to 2 built-in timers: timer0 and timer1, + usually at least one of them exists. Either of them is supported + in U-Boot. + endmenu diff --git a/drivers/timer/Makefile b/drivers/timer/Makefile index ae94be8..bfe65fc 100644 --- a/drivers/timer/Makefile +++ b/drivers/timer/Makefile @@ -11,3 +11,4 @@ obj-$(CONFIG_X86_TSC_TIMER) += tsc_timer.o obj-$(CONFIG_OMAP_TIMER) += omap-timer.o obj-$(CONFIG_AST_TIMER) += ast_timer.o obj-$(CONFIG_STI_TIMER) += sti-timer.o +obj-$(CONFIG_ARC_TIMER) += arc_timer.o diff --git a/drivers/timer/arc_timer.c b/drivers/timer/arc_timer.c new file mode 100644 index 0000000..e94e4a4 --- /dev/null +++ b/drivers/timer/arc_timer.c @@ -0,0 +1,113 @@ +/* + * Copyright (C) 2016 Synopsys, Inc. All rights reserved. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <dm.h> +#include <errno.h> +#include <timer.h> +#include <asm/arcregs.h> +#include <asm/io.h> + +DECLARE_GLOBAL_DATA_PTR; + +#define NH_MODE (1 << 1) + +/* + * ARC timer control registers are mapped to auxiliary address space. + * There are special ARC asm command to access that addresses. + * Therefore we use built-in functions to read from and write to timer + * control register. + */ + +/* Driver private data. Contains timer id. Could be either 0 or 1. */ +struct arc_timer_priv { + uint timer_id; +}; + +static int arc_timer_get_count(struct udevice *dev, u64 *count) +{ + u32 val = 0; + struct arc_timer_priv *priv = dev_get_priv(dev); + + switch (priv->timer_id) { + case 0: + val = read_aux_reg(ARC_AUX_TIMER0_CNT); + break; + case 1: + val = read_aux_reg(ARC_AUX_TIMER1_CNT); + break; + } + *count = timer_conv_64(val); + + return 0; +} + +static int arc_timer_probe(struct udevice *dev) +{ + int id; + struct arc_timer_priv *priv = dev_get_priv(dev); + + /* Get registers offset and size */ + id = fdtdec_get_int(gd->fdt_blob, dev->of_offset, "reg", -1); + if (id < 0) + return -EINVAL; + + if (id > 1) + return -ENXIO; + + priv->timer_id = (uint)id; + + /* + * In ARC core there're special registers (Auxiliary or AUX) in its + * separate memory space that are used for accessing some hardware + * features of the core. They are not mapped in normal memory space + * and also always have the same location regardless core configuration. + * Thus to simplify understanding of the programming model we chose to + * access AUX regs of Timer0 and Timer1 separately instead of using + * offsets from some base address. + */ + + switch (priv->timer_id) { + case 0: + /* Disable timer if CPU is halted */ + write_aux_reg(ARC_AUX_TIMER0_CTRL, NH_MODE); + /* Set max value for counter/timer */ + write_aux_reg(ARC_AUX_TIMER0_LIMIT, 0xffffffff); + /* Set initial count value and restart counter/timer */ + write_aux_reg(ARC_AUX_TIMER0_CNT, 0); + break; + case 1: + /* Disable timer if CPU is halted */ + write_aux_reg(ARC_AUX_TIMER1_CTRL, NH_MODE); + /* Set max value for counter/timer */ + write_aux_reg(ARC_AUX_TIMER1_LIMIT, 0xffffffff); + /* Set initial count value and restart counter/timer */ + write_aux_reg(ARC_AUX_TIMER1_CNT, 0); + break; + } + + return 0; +} + + +static const struct timer_ops arc_timer_ops = { + .get_count = arc_timer_get_count, +}; + +static const struct udevice_id arc_timer_ids[] = { + { .compatible = "snps,arc-timer" }, + {} +}; + +U_BOOT_DRIVER(arc_timer) = { + .name = "arc_timer", + .id = UCLASS_TIMER, + .of_match = arc_timer_ids, + .probe = arc_timer_probe, + .ops = &arc_timer_ops, + .flags = DM_FLAG_PRE_RELOC, + .priv_auto_alloc_size = sizeof(struct arc_timer_priv), +}; |