[PATCH v2 12/12] clocksource: samsung-time: Add Device Tree support

On 02/16/2013 10:44 AM, Tomasz Figa wrote:

This patch adds support for parsing all platform-specific data from
Device Tree and instantiation using clocksource_of_init to samsung-time
clocksource driver.

+Optional properties:
+- samsung,source-timer: index of timer to be used as clocksource (defaults to 4)
+- samsung,event-timer: index of timer to be used as clock event (defaults to 3)

This is Linux specific, not a h/w property. Define the h/w properties of
the timers so that Linux can decide which timer to use. See the omap2
timers for an example.

Shouldn't need 2 match tables and the data here is kind of pointless
when you can just use the compatible string.

+	{},
+};
+
+static void samsung_timer_parse_dt(struct device_node *np,
+					const struct of_device_id *match)
+{
+	int i;
+	u32 val;
+
+	timer_base = of_iomap(np, 0);
+	if (!timer_base)
+		panic("failed to map timer registers");
+
+	for (i = 0; i < SAMSUNG_PWM_NUM; ++i)
+		timer_variant.irqs[i] = irq_of_parse_and_map(np, i);
+
+	if (!timer_variant.irqs[timer_source.event_id])
+		panic("no clock event irq provided");
+
+	switch ((unsigned int)match->data) {
+	case TYPE_S3C24XX:
+		timer_variant.bits = 16;
+		timer_variant.prescale = 25;
+		timer_variant.prescale = 50;
+		timer_variant.has_tint_cstat = false;
+		break;
+	case TYPE_S3C64XX:
+		timer_variant.bits = 32;
+		timer_variant.prescale = 2;
+		timer_variant.divisor = 2;
+		timer_variant.has_tint_cstat = true;
+		break;
+	}
+
+	timer_source.source_id = 4;
+	if (!of_property_read_u32(np, "samsung,source-timer", &val)) {
+		if (val >= SAMSUNG_PWM_NUM)
+			panic("samsung,source-timer property out of range");
+		timer_source.source_id = val;
+	}
+
+	timer_source.event_id = 3;
+	if (!of_property_read_u32(np, "samsung,event-timer", &val)) {
+		if (val >= SAMSUNG_PWM_NUM)
+			panic("samsung,event-timer property out of range");
+		timer_source.event_id = val;
+	}
+
+	if (!of_property_read_u32(np, "samsung,prescale-divisor", &val)) {
+		if (val < 1 || val > 256)
+			panic("samsung,prescale-divisor property out of range");
+		timer_variant.prescale = val;
+	}
+
+	if (!of_property_read_u32(np, "samsung,divisor", &val)) {
+		switch (val) {
+		case 1:
+		case 2:
+		case 4:
+		case 8:
+		case 16:
+			timer_variant.divisor = timer_variant.prescale * val;
+			break;
+		default:
+			panic("invalid value of samsung,divisor property");
+		}
+	}
+}
+#endif
+
 void __init samsung_timer_init(void)
 {
+#ifdef CONFIG_OF
+	struct device_node *np;
+	const struct of_device_id *match;
+
+	if (of_have_populated_dt()) {

Separate the OF and non-OF code to avoid this and the ifdef.

+		np = of_find_matching_node_and_match(NULL,
+						samsung_timer_ids, &match);
+		if (!np)
+			panic("timer node not found");

I have a patch to change this function to pass in the node ptr and avoid
matching twice. It should be in arm-soc shortly after rc1.

Rob