On Wed, Jan 10, 2018 at 4:48 PM, Paul Cercueil <paul@xxxxxxxxxxxxxxx> 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 <paul@xxxxxxxxxxxxxxx>
---
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).