[PATCH v2 3/6] rtc: renesas-rtca3: Use OF data for configuration

Ovidiu Panait
2025-10-21T08:07:28Z

Prepare for adding support for the Renesas RZ/V2H SoC RTC IP by making the
driver configuration selectable via OF match data.

For RZ/V2H RTC, the maximum periodic interrupt frequency is 128Hz instead
of 256Hz, so add this info to a SoC-specific struct and retrieve it
during probe.

Signed-off-by: Ovidiu Panait <ovidiu.panait.rb@renesas.com>
---
v2 changes: none

drivers/rtc/rtc-renesas-rtca3.c | 20 ++++++++++++++++++--
1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/rtc/rtc-renesas-rtca3.c b/drivers/rtc/rtc-renesas-rtca3.c
index ab816bdf0d77..90dda04fad33 100644
--- a/drivers/rtc/rtc-renesas-rtca3.c
+++ b/drivers/rtc/rtc-renesas-rtca3.c
@@ -101,6 +101,15 @@ enum rtca3_alrm_set_step {
RTCA3_ALRM_SSTEP_INIT = 3,
};

+/**
+ * struct rtca3_of_data - OF data for RTCA3
+ *
+ * @max_periodic_irq_freq: maximum periodic interrupt frequency
+ */
+struct rtca3_of_data {
+ int max_periodic_irq_freq;
+};
+
/**
* struct rtca3_ppb_per_cycle - PPB per cycle
* @ten_sec: PPB per cycle in 10 seconds adjutment mode
@@ -709,6 +718,7 @@ static void rtca3_action(void *data)

static int rtca3_probe(struct platform_device *pdev)
{
+ const struct rtca3_of_data *of_data;
struct device *dev = &pdev->dev;
struct rtca3_priv *priv;
struct clk *clk;
@@ -718,6 +728,8 @@ static int rtca3_probe(struct platform_device *pdev)
if (!priv)
return -ENOMEM;

+ of_data = of_device_get_match_data(dev);
+
priv->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(priv->base))
return PTR_ERR(priv->base);
@@ -772,7 +784,7 @@ static int rtca3_probe(struct platform_device *pdev)
return PTR_ERR(priv->rtc_dev);

priv->rtc_dev->ops = &rtca3_ops;
- priv->rtc_dev->max_user_freq = 256;
+ priv->rtc_dev->max_user_freq = of_data->max_periodic_irq_freq;
priv->rtc_dev->range_min = RTC_TIMESTAMP_BEGIN_2000;
priv->rtc_dev->range_max = RTC_TIMESTAMP_END_2099;

@@ -875,8 +887,12 @@ static int rtca3_resume(struct device *dev)

static DEFINE_SIMPLE_DEV_PM_OPS(rtca3_pm_ops, rtca3_suspend, rtca3_resume);

+static const struct rtca3_of_data rtca3_of_data = {
+ .max_periodic_irq_freq = 256,
+};
+
static const struct of_device_id rtca3_of_match[] = {
- { .compatible = "renesas,rz-rtca3", },
+ { .compatible = "renesas,rz-rtca3", .data = &rtca3_of_data },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, rtca3_of_match);
--
2.51.0