Re: [PATCH v5 4/5] wifi: brcmfmac: Add optional lpo clock enable support

[Stefan Wahren]

Hi Jacobe,

Am 30.07.24 um 05:30 schrieb Jacobe Zang:
> WiFi modules often require 32kHz clock to function. Add support to
> enable the clock to PCIe driver.
>
> Co-developed-by: Ondrej Jirman <megi@xxxxxx>
> Signed-off-by: Ondrej Jirman <megi@xxxxxx>
> Signed-off-by: Jacobe Zang <jacobe.zang@xxxxxxxxxx>
> ---
>   drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c | 8 ++++++++
>   1 file changed, 8 insertions(+)
>
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c
> index e406e11481a62..6246e3fd7399f 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c
> @@ -6,6 +6,7 @@
>   #include <linux/of.h>
>   #include <linux/of_irq.h>
>   #include <linux/of_net.h>
> +#include <linux/clk.h>
>
>   #include <defs.h>
>   #include "debug.h"
> @@ -70,6 +71,7 @@ void brcmf_of_probe(struct device *dev, enum brcmf_bus_type bus_type,
>   {
>   	struct brcmfmac_sdio_pd *sdio = &settings->bus.sdio;
>   	struct device_node *root, *np = dev->of_node;
> +	struct clk *clk;
>   	const char *prop;
>   	int irq;
>   	int err;
> @@ -113,6 +115,12 @@ void brcmf_of_probe(struct device *dev, enum brcmf_bus_type bus_type,
>   		of_node_put(root);
>   	}
>
> +	clk = devm_clk_get_optional_enabled(dev, "lpo");
> +	if (!IS_ERR_OR_NULL(clk)) {
> +		brcmf_dbg(INFO, "enabling 32kHz clock\n");
> +		clk_set_rate(clk, 32768);
> +	}
even if the clock is optional, there should be a proper error handling
(e.g. the -EPROBE_DEFER case).

Best regards
> +
>   	if (!np || !of_device_is_compatible(np, "brcm,bcm4329-fmac"))
>   		return;