Re: [PATCH v3 04/15] can: grcan: Add clock handling

Marc Kleine-Budde
2026-01-23T13:44:41Z

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On 22.01.2026 13:10:27, Arun Muthusamy wrote:
> From: Daniel Hellstrom <daniel@gaisler.com>
>
> Add clock handling and add error messages for missing 'freq' DT property.
>
> Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>
> Signed-off-by: Arun Muthusamy <arun.muthusamy@gaisler.com>
> ---
> drivers/net/can/grcan.c | 19 ++++++++++++++++---
> 1 file changed, 16 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/can/grcan.c b/drivers/net/can/grcan.c
> index 3b1b09943436..538a9b4f82ab 100644
> --- a/drivers/net/can/grcan.c
> +++ b/drivers/net/can/grcan.c
> @@ -34,7 +34,7 @@
> #include <linux/spinlock.h>
> #include <linux/of.h>
> #include <linux/of_irq.h>
> -
> +#include <linux/clk.h>
> #include <linux/dma-mapping.h>
>
> #define DRV_NAME "grcan"
> @@ -1644,6 +1644,7 @@ static int grcan_probe(struct platform_device *ofdev)
> {
> struct device_node *np = ofdev->dev.of_node;
> struct device_node *sysid_parent;
> + struct clk *clk;
> u32 sysid, ambafreq;
> int irq, err;
> void __iomem *base;
> @@ -1663,8 +1664,20 @@ static int grcan_probe(struct platform_device *ofdev)
>
> err = of_property_read_u32(np, "freq", &ambafreq);
> if (err) {
> - dev_err(&ofdev->dev, "unable to fetch \"freq\" property\n");
> - goto exit_error;
> + clk = devm_clk_get(&ofdev->dev, NULL);
> + if (IS_ERR(clk)) {
> + dev_err_probe(&ofdev->dev, PTR_ERR(clk),
> + "Failed both to get \"freq\" property and clock for fallback\n");
> + err = PTR_ERR(clk);
> + goto exit_error;
> + }

I think devm_clk_get() either returns an error pointer or a valid clock
pointer.

> + if (clk) {
> + ambafreq = clk_get_rate(clk);
> + if (!ambafreq) {
> + dev_err(&ofdev->dev, "Invalid or Uninitialized clock\n");
> + return -EINVAL;
> + }
> + }
> }
>
> base = devm_platform_ioremap_resource(ofdev, 0);

Marc
--
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