From fc6a6772f888ee8ab4c5428854f7f1d3abda13df Mon Sep 17 00:00:00 2001 From: Ezequiel Garcia Date: Mon, 27 Jul 2015 15:00:15 +0100 Subject: [PATCH] CLOCKSOURCE: mips-gic: Update clockevent frequency on clock rate changes This commit introduces the clockevent frequency update, using a clock notifier. It will be used to support CPUFreq on platforms using MIPS GIC based clockevents. Signed-off-by: Ezequiel Garcia Acked-by: Daniel Lezcano Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: devicetree@vger.kernel.org Cc: Thomas Gleixner Cc: Andrew Bresticker Cc: James Hartley Cc: Govindraj Raja Cc: Damien Horsley Cc: James Hogan Cc: Ezequiel Garcia Patchwork: https://patchwork.linux-mips.org/patch/10782/ Signed-off-by: Ralf Baechle --- drivers/clocksource/mips-gic-timer.c | 31 +++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-) diff --git a/drivers/clocksource/mips-gic-timer.c b/drivers/clocksource/mips-gic-timer.c index 22a4daf5f0c8..a155bec06d18 100644 --- a/drivers/clocksource/mips-gic-timer.c +++ b/drivers/clocksource/mips-gic-timer.c @@ -79,6 +79,13 @@ static void gic_clockevent_cpu_exit(struct clock_event_device *cd) disable_percpu_irq(gic_timer_irq); } +static void gic_update_frequency(void *data) +{ + unsigned long rate = (unsigned long)data; + + clockevents_update_freq(this_cpu_ptr(&gic_clockevent_device), rate); +} + static int gic_cpu_notifier(struct notifier_block *nb, unsigned long action, void *data) { @@ -94,10 +101,26 @@ static int gic_cpu_notifier(struct notifier_block *nb, unsigned long action, return NOTIFY_OK; } +static int gic_clk_notifier(struct notifier_block *nb, unsigned long action, + void *data) +{ + struct clk_notifier_data *cnd = data; + + if (action == POST_RATE_CHANGE) + on_each_cpu(gic_update_frequency, (void *)cnd->new_rate, 1); + + return NOTIFY_OK; +} + + static struct notifier_block gic_cpu_nb = { .notifier_call = gic_cpu_notifier, }; +static struct notifier_block gic_clk_nb = { + .notifier_call = gic_clk_notifier, +}; + static int gic_clockevent_init(void) { int ret; @@ -160,6 +183,7 @@ void __init gic_clocksource_init(unsigned int frequency) static void __init gic_clocksource_of_init(struct device_node *node) { struct clk *clk; + int ret; if (WARN_ON(!gic_present || !node->parent || !of_device_is_compatible(node->parent, "mti,gic"))) @@ -186,7 +210,12 @@ static void __init gic_clocksource_of_init(struct device_node *node) } __gic_clocksource_init(); - gic_clockevent_init(); + + ret = gic_clockevent_init(); + if (!ret && !IS_ERR(clk)) { + if (clk_notifier_register(clk, &gic_clk_nb) < 0) + pr_warn("GIC: Unable to register clock notifier\n"); + } /* And finally start the counter */ gic_start_count(); -- 2.34.1