From 9883f7c8dd21acb90697582ca331f3f8a66ac054 Mon Sep 17 00:00:00 2001 From: Jon Hunter Date: Tue, 9 Oct 2012 14:12:26 -0500 Subject: [PATCH] ARM: OMAP2+: Add device-tree support for 32kHz counter For OMAP devices, the 32kHz counter is the default clock-source for the kernel. However, this is not the only possible clock-source the kernel can use for OMAP devices. When booting with device-tree, if the 32kHz counter is the desired clock-source for the kernel, then parse the device-tree blob to ensure that the counter is present and if so map memory for the counter using the device-tree of_iomap() function so we are no longer reliant on the OMAP HWMOD framework to do this for us. Signed-off-by: Jon Hunter --- arch/arm/mach-omap2/timer.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c index 92447cd7a41a..0758bae3a57a 100644 --- a/arch/arm/mach-omap2/timer.c +++ b/arch/arm/mach-omap2/timer.c @@ -159,6 +159,11 @@ static struct of_device_id omap_timer_match[] __initdata = { { } }; +static struct of_device_id omap_counter_match[] __initdata = { + { .compatible = "ti,omap-counter32k", }, + { } +}; + /** * omap_get_timer_dt - get a timer using device-tree * @match - device-tree match structure for matching a device type @@ -377,10 +382,25 @@ static u32 notrace dmtimer_read_sched_clock(void) static int __init omap2_sync32k_clocksource_init(void) { int ret; + struct device_node *np = NULL; struct omap_hwmod *oh; void __iomem *vbase; const char *oh_name = "counter_32k"; + /* + * If device-tree is present, then search the DT blob + * to see if the 32kHz counter is supported. + */ + if (of_have_populated_dt()) { + np = omap_get_timer_dt(omap_counter_match, NULL); + if (!np) + return -ENODEV; + + of_property_read_string_index(np, "ti,hwmods", 0, &oh_name); + if (!oh_name) + return -ENODEV; + } + /* * First check hwmod data is available for sync32k counter */ @@ -390,7 +410,13 @@ static int __init omap2_sync32k_clocksource_init(void) omap_hwmod_setup_one(oh_name); - vbase = omap_hwmod_get_mpu_rt_va(oh); + if (np) { + vbase = of_iomap(np, 0); + of_node_put(np); + } else { + vbase = omap_hwmod_get_mpu_rt_va(oh); + } + if (!vbase) { pr_warn("%s: failed to get counter_32k resource\n", __func__); return -ENXIO; -- GitLab