[PATCH v31 2/5] i2c: aspeed: Read clock-frequency via i2c_parse_fw_timings()

[Ryan Chen]

Use i2c_parse_fw_timings() to read the standard "clock-frequency"
property, and fall back to "bus-frequency" only when the standard
property is absent.

This honors device trees written against the updated
aspeed,ast2600-i2c binding without silently falling back to 100 kHz,
while keeping existing in-tree device trees using "bus-frequency"
working.

Signed-off-by: Ryan Chen <ryan_chen at aspeedtech.com>
---
Changes in v31:
- Zero-initialise `struct i2c_timings timings` so the bus-frequency
  fallback runs when clock-frequency is absent (Sashiko AI review).
---
 drivers/i2c/busses/i2c-aspeed.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c
index a26b74c71206..f00bd779146e 100644
--- a/drivers/i2c/busses/i2c-aspeed.c
+++ b/drivers/i2c/busses/i2c-aspeed.c
@@ -1000,6 +1000,7 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev)
 	const struct of_device_id *match;
 	struct aspeed_i2c_bus *bus;
 	struct clk *parent_clk;
+	struct i2c_timings timings = {};
 	int irq, ret;
 
 	bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
@@ -1025,12 +1026,18 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev)
 	}
 	reset_control_deassert(bus->rst);
 
-	ret = of_property_read_u32(pdev->dev.of_node,
-				   "bus-frequency", &bus->bus_frequency);
-	if (ret < 0) {
-		dev_err(&pdev->dev,
-			"Could not read bus-frequency property\n");
-		bus->bus_frequency = I2C_MAX_STANDARD_MODE_FREQ;
+	i2c_parse_fw_timings(&pdev->dev, &timings, false);
+	if (timings.bus_freq_hz) {
+		bus->bus_frequency = timings.bus_freq_hz;
+	} else {
+		ret = of_property_read_u32(pdev->dev.of_node,
+					   "bus-frequency",
+					   &bus->bus_frequency);
+		if (ret < 0) {
+			dev_err(&pdev->dev,
+				"Could not read clock-frequency or bus-frequency property\n");
+			bus->bus_frequency = I2C_MAX_STANDARD_MODE_FREQ;
+		}
 	}
 
 	match = of_match_node(aspeed_i2c_bus_of_table, pdev->dev.of_node);

-- 
2.34.1