[PATCH v2 08/14] rtc: sun6i: Expose internal oscillator through device tree

[Chen-Yu Tsai <wens@csie.org>]

The bindings have been updated to expose the RTC's internal oscillator,
for some SoCs that have it directly feeding the PRCM block. The changes
include the index 2 for the clock outputs, as well as the clock output
names.

This patch adds the internal oscillator to the list of clocks exposed
through of_clk_add_hw_provider(), and also have the driver optionally
fetch the name of the clock from the device tree if it's available.

Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
 drivers/rtc/rtc-sun6i.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c
index 46609ae56ffd..11f56de52179 100644
--- a/drivers/rtc/rtc-sun6i.c
+++ b/drivers/rtc/rtc-sun6i.c
@@ -136,6 +136,7 @@ struct sun6i_rtc_clk_data {
 	unsigned int fixed_prescaler : 16;
 	unsigned int has_prescaler : 1;
 	unsigned int has_out_clk : 1;
+	unsigned int export_iosc : 1;
 };
 
 struct sun6i_rtc_dev {
@@ -220,6 +221,7 @@ static void __init sun6i_rtc_clk_init(struct device_node *node,
 		.ops		= &sun6i_rtc_osc_ops,
 		.name		= "losc",
 	};
+	const char *iosc_name = "rtc-int-osc";
 	const char *clkout_name = "osc32k-out";
 	const char *parents[2];
 
@@ -228,7 +230,7 @@ static void __init sun6i_rtc_clk_init(struct device_node *node,
 		return;
 
 	rtc->data = data;
-	clk_data = kzalloc(struct_size(clk_data, hws, 2), GFP_KERNEL);
+	clk_data = kzalloc(struct_size(clk_data, hws, 3), GFP_KERNEL);
 	if (!clk_data) {
 		kfree(rtc);
 		return;
@@ -253,8 +255,13 @@ static void __init sun6i_rtc_clk_init(struct device_node *node,
 	if (!of_get_property(node, "clocks", NULL))
 		goto err;
 
+	/* Only read IOSC name from device tree if it is exported */
+	if (rtc->data->export_iosc)
+		of_property_read_string_index(node, "clock-output-names", 2,
+					      &iosc_name);
+
 	rtc->int_osc = clk_hw_register_fixed_rate_with_accuracy(NULL,
-								"rtc-int-osc",
+								iosc_name,
 								NULL, 0,
 								rtc->data->rc_osc_rate,
 								300000000);
@@ -293,6 +300,10 @@ static void __init sun6i_rtc_clk_init(struct device_node *node,
 	clk_data->num = 2;
 	clk_data->hws[0] = &rtc->hw;
 	clk_data->hws[1] = __clk_get_hw(rtc->ext_losc);
+	if (rtc->data->export_iosc) {
+		clk_data->hws[2] = rtc->int_osc;
+		clk_data->num = 3;
+	}
 	of_clk_add_hw_provider(node, of_clk_hw_onecell_get, clk_data);
 	return;
 
@@ -330,6 +341,7 @@ static const struct sun6i_rtc_clk_data sun8i_h3_rtc_data = {
 	.fixed_prescaler = 32,
 	.has_prescaler = 1,
 	.has_out_clk = 1,
+	.export_iosc = 1,
 };
 
 static void __init sun8i_h3_rtc_clk_init(struct device_node *node)
-- 
2.20.0.rc1