diff options
| -rw-r--r-- | arch/m68knommu/platform/coldfire/Makefile | 2 | ||||
| -rw-r--r-- | arch/m68knommu/platform/coldfire/dma_timer.c | 68 |
2 files changed, 69 insertions, 1 deletions
diff --git a/arch/m68knommu/platform/coldfire/Makefile b/arch/m68knommu/platform/coldfire/Makefile index 40cf20be1b9..4f416a91a82 100644 --- a/arch/m68knommu/platform/coldfire/Makefile +++ b/arch/m68knommu/platform/coldfire/Makefile @@ -18,7 +18,7 @@ obj-$(CONFIG_COLDFIRE) += dma.o entry.o vectors.o obj-$(CONFIG_M5206) += timers.o obj-$(CONFIG_M5206e) += timers.o obj-$(CONFIG_M520x) += pit.o -obj-$(CONFIG_M523x) += pit.o +obj-$(CONFIG_M523x) += pit.o dma_timer.o obj-$(CONFIG_M5249) += timers.o obj-$(CONFIG_M527x) += pit.o obj-$(CONFIG_M5272) += timers.o diff --git a/arch/m68knommu/platform/coldfire/dma_timer.c b/arch/m68knommu/platform/coldfire/dma_timer.c new file mode 100644 index 00000000000..b623c993219 --- /dev/null +++ b/arch/m68knommu/platform/coldfire/dma_timer.c @@ -0,0 +1,68 @@ +/* + * dma_timer.c -- Freescale ColdFire DMA Timer. + * + * Copyright (C) 2007, Benedikt Spranger <b.spranger@linutronix.de> + * Copyright (C) 2008. Sebastian Siewior, Linutronix + * + */ + +#include <linux/clocksource.h> +#include <linux/io.h> + +#include <asm/machdep.h> +#include <asm/coldfire.h> +#include <asm/mcfpit.h> +#include <asm/mcfsim.h> + +#define DMA_TIMER_0 (0x00) +#define DMA_TIMER_1 (0x40) +#define DMA_TIMER_2 (0x80) +#define DMA_TIMER_3 (0xc0) + +#define DTMR0 (MCF_IPSBAR + DMA_TIMER_0 + 0x400) +#define DTXMR0 (MCF_IPSBAR + DMA_TIMER_0 + 0x402) +#define DTER0 (MCF_IPSBAR + DMA_TIMER_0 + 0x403) +#define DTRR0 (MCF_IPSBAR + DMA_TIMER_0 + 0x404) +#define DTCR0 (MCF_IPSBAR + DMA_TIMER_0 + 0x408) +#define DTCN0 (MCF_IPSBAR + DMA_TIMER_0 + 0x40c) + +#define DMA_FREQ ((MCF_CLK / 2) / 16) + +/* DTMR */ +#define DMA_DTMR_RESTART (1 << 3) +#define DMA_DTMR_CLK_DIV_1 (1 << 1) +#define DMA_DTMR_CLK_DIV_16 (2 << 1) +#define DMA_DTMR_ENABLE (1 << 0) + +static cycle_t cf_dt_get_cycles(void) +{ + return __raw_readl(DTCN0); +} + +static struct clocksource clocksource_cf_dt = { + .name = "coldfire_dma_timer", + .rating = 200, + .read = cf_dt_get_cycles, + .mask = CLOCKSOURCE_MASK(32), + .shift = 20, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static int __init init_cf_dt_clocksource(void) +{ + /* + * We setup DMA timer 0 in free run mode. This incrementing counter is + * used as a highly precious clock source. With MCF_CLOCK = 150 MHz we + * get a ~213 ns resolution and the 32bit register will overflow almost + * every 15 minutes. + */ + __raw_writeb(0x00, DTXMR0); + __raw_writeb(0x00, DTER0); + __raw_writel(0x00000000, DTRR0); + __raw_writew(DMA_DTMR_CLK_DIV_16 | DMA_DTMR_ENABLE, DTMR0); + clocksource_cf_dt.mult = clocksource_hz2mult(DMA_FREQ, + clocksource_cf_dt.shift); + return clocksource_register(&clocksource_cf_dt); +} + +arch_initcall(init_cf_dt_clocksource); |