On Wed, Jan 10, 2018 at 4:48 PM, Paul Cercueil [off-list ref] wrote:

This driver will use the TCU (Timer Counter Unit) present on the Ingenic
JZ47xx SoCs to provide the kernel with a clocksource and timers.

Signed-off-by: Paul Cercueil <redacted>
---
 drivers/clocksource/Kconfig         |   8 ++
 drivers/clocksource/Makefile        |   1 +
 drivers/clocksource/timer-ingenic.c | 258 ++++++++++++++++++++++++++++++++++++
 3 files changed, 267 insertions(+)
 create mode 100644 drivers/clocksource/timer-ingenic.c

 v2: Use SPDX identifier for the license
 v3: - Move documentation to its own patch
     - Search the devicetree for PWM clients, and use all the TCU
           channels that won't be used for PWM

[...]

+static int __init ingenic_tcu_init(struct device_node *np)
+{
+       unsigned long available_channels = GENMASK(NUM_CHANNELS - 1, 0);
+       struct device_node *node;
+       struct ingenic_tcu *tcu;
+       unsigned int i, channel;
+       int err;
+       u32 val;
+
+       for_each_node_with_property(node, "pwms") {
+               err = of_property_read_u32_index(node, "pwms", 1, &val);

This is the right idea, but a bit fragile. Perhaps its good enough for
your platform, but it would fail if you have another PWM provider like
the gpio-pwm binding or the cell size is not 1 (BTW, I thought the PWM
binding defined 3 cells typically).

Rob
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html