On 10/07/2015 01:35 PM, Marc Gonzalez wrote:
Sigma Designs Tango platforms provide a 27 MHz crystal oscillator.
Use it for clocksource, sched_clock, and delay_timer.
Signed-off-by: Marc Gonzalez <[email protected]>
---
AFAICS, clocksource_register_hz does not report failures via its
return value (always 0) but writes warnings to stdout?
Yeah, it returns always 0. I suggest you assume it is returning an error
code, that will be safer for future changes in the framework (if any).
Open question: can I call register_current_timer_delay,
sched_clock_register, clocksource_register_hz in any order?
---
Yes, I think so. Thomas ?
[ ... ]
+static void __init tango_clocksource_init(struct device_node *np)
+{
+ struct clk *clk = of_clk_get(np, 0);
+ unsigned int xtal_freq = clk_get_rate(clk);
+ xtal_in_cnt = of_iomap(np, 0);
+ if (xtal_in_cnt == NULL)
+ panic("%s: of_iomap failed\n", np->full_name);
^^^^^^^^^^^
That does not comply with the Linux kernel coding style.
xtal_in_cnt = of_iomap(np, 0);
if (!xtal_in_cnt) {
pr_err("Argh!");
return;
}
clk = of_clk_get(np, 0);
if (!clk) {
pr_err("grumf!");
return;
}
freq = clk_get_rate(clk);
+
+ delay_timer.freq = xtal_freq;
+ delay_timer.read_current_timer = read_xtal_counter;
+ register_current_timer_delay(&delay_timer);
+ sched_clock_register(read_sched_clock, 32, xtal_freq);
+ clocksource_register_hz(&tango_xtal, xtal_freq);
ret = clocksource_register_hz(&tango_xtal, xtal_freq);
if (ret) {
pr_err("oups!");
return;
}
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