CLOCKSOURCE: mips-gic: Enable the clock before using it

For the clock to be used (e.g. get its rate through clk_get_rate)
it should be prepared and enabled first.

Also, while the clock is enabled the driver must hold a reference to it,
so let's remove the call to clk_put.

Reviewed-by: Andrew Bresticker <abrestic@chromium.org>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: James Hartley <James.Hartley@imgtec.com>
Cc: Govindraj Raja <Govindraj.Raja@imgtec.com>
Cc: Damien Horsley <Damien.Horsley@imgtec.com>
Cc: James Hogan <James.Hogan@imgtec.com>
Cc: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Patchwork: https://patchwork.linux-mips.org/patch/10779/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/clocksource/mips-gic-timer.c b/drivers/clocksource/mips-gic-timer.c
index b81ed1a5342d..913585d93466 100644
--- a/drivers/clocksource/mips-gic-timer.c
+++ b/drivers/clocksource/mips-gic-timer.c
@@ -158,8 +158,13 @@ static void __init gic_clocksource_of_init(struct device_node *node)
 
         clk = of_clk_get(node, 0);
         if (!IS_ERR(clk)) {
+                if (clk_prepare_enable(clk) < 0) {
+                        pr_err("GIC failed to enable clock\n");
+                        clk_put(clk);
+                        return;
+                }
+
                 gic_frequency = clk_get_rate(clk);
-                clk_put(clk);
         } else if (of_property_read_u32(node, "clock-frequency",
                                         &gic_frequency)) {
                 pr_err("GIC frequency not specified.\n");