[PATCH net 09/22] can: cc770: fix the clock divider check on the platform bus

[Marc Kleine-Budde <mkl@pengutronix.de>]

From: Quchaosheng <quchaosheng000406@163.com>

cc770_get_platform_data() tests priv->cpu_interface for CPUIF_DSC before
assigning it from pdata->cir:

	priv->can.clock.freq = pdata->osc_freq;
	if (priv->cpu_interface & CPUIF_DSC)
		priv->can.clock.freq /= 2;
	priv->clkout = pdata->cor;
	priv->bus_config = pdata->bcr;
	priv->cpu_interface = pdata->cir;

priv comes from alloc_cc770dev() -> alloc_candev() -> alloc_netdev_mqs(),
which uses kvzalloc_flex(), so cpu_interface is still zero here and the
test can never match.

A board that sets CPUIF_DSC in pdata->cir therefore gets its system clock
halved in the hardware but not in can.clock.freq, and the bit timing is
computed from twice the real clock. The platform data example in the file
header, .cir = 0x41, sets that bit.

Assign pdata->cir before the test, as the ISA path in cc770_isa.c already
does.

Fixes: e285e44d91fe ("can: cc770: add platform bus driver for the CC770 and AN82527")
Assisted-by: LLM
Signed-off-by: Quchaosheng <quchaosheng000406@163.com>
Link: https://patch.msgid.link/20260917114311.534863-1-quchaosheng000406@163.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/cc770/cc770_platform.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/can/cc770/cc770_platform.c b/drivers/net/can/cc770/cc770_platform.c
index ac218acedb10..c7dfcff4e1ce 100644
--- a/drivers/net/can/cc770/cc770_platform.c
+++ b/drivers/net/can/cc770/cc770_platform.c
@@ -137,11 +137,11 @@ static int cc770_get_platform_data(struct platform_device *pdev,
 	struct cc770_platform_data *pdata = dev_get_platdata(&pdev->dev);
 
 	priv->can.clock.freq = pdata->osc_freq;
+	priv->cpu_interface = pdata->cir;
 	if (priv->cpu_interface & CPUIF_DSC)
 		priv->can.clock.freq /= 2;
 	priv->clkout = pdata->cor;
 	priv->bus_config = pdata->bcr;
-	priv->cpu_interface = pdata->cir;
 
 	return 0;
 }
-- 
2.53.0