linux-kernel - Re: [PATCH v10 4/5] wifi: brcmfmac: Add optional lpo clock enable support

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Message-ID: <721da64c-42ec-4be6-8ad3-e2685a84823a@broadcom.com>
Date: Tue, 13 Aug 2024 13:57:28 +0200
From: Arend van Spriel <arend.vanspriel@...adcom.com>
To: Jacobe Zang <jacobe.zang@...ion.com>, robh@...nel.org,
 krzk+dt@...nel.org, heiko@...ech.de, kvalo@...nel.org, davem@...emloft.net,
 edumazet@...gle.com, kuba@...nel.org, pabeni@...hat.com, conor+dt@...nel.org
Cc: efectn@...tonmail.com, dsimic@...jaro.org, jagan@...eble.ai,
 devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
 linux-rockchip@...ts.infradead.org, linux-kernel@...r.kernel.org,
 arend@...adcom.com, linux-wireless@...r.kernel.org, netdev@...r.kernel.org,
 megi@....cz, duoming@....edu.cn, bhelgaas@...gle.com,
 minipli@...ecurity.net, brcm80211@...ts.linux.dev,
 brcm80211-dev-list.pdl@...adcom.com, nick@...das.com,
 Sai Krishna <saikrishnag@...vell.com>
Subject: Re: [PATCH v10 4/5] wifi: brcmfmac: Add optional lpo clock enable
 support

On 8/13/2024 10:20 AM, Jacobe Zang wrote:
> WiFi modules often require 32kHz clock to function. Add support to
> enable the clock to PCIe driver and move "brcm,bcm4329-fmac" check
> to the top of brcmf_of_probe. Change function prototypes from void
> to int and add appropriate errno's for return values that will be
> send to bus when error occurred.

I was going to say it looks good to me, but....

> Co-developed-by: Ondrej Jirman <megi@....cz>
> Signed-off-by: Ondrej Jirman <megi@....cz>
> Co-developed-by: Arend van Spriel <arend.vanspriel@...adcom.com>
> Signed-off-by: Arend van Spriel <arend.vanspriel@...adcom.com>
> Reviewed-by: Sai Krishna <saikrishnag@...vell.com>
> Signed-off-by: Jacobe Zang <jacobe.zang@...ion.com>
> ---
>   .../broadcom/brcm80211/brcmfmac/bcmsdh.c      |  4 +-
>   .../broadcom/brcm80211/brcmfmac/common.c      |  3 +-
>   .../wireless/broadcom/brcm80211/brcmfmac/of.c | 53 +++++++++++--------
>   .../wireless/broadcom/brcm80211/brcmfmac/of.h |  9 ++--
>   .../broadcom/brcm80211/brcmfmac/pcie.c        |  3 ++
>   .../broadcom/brcm80211/brcmfmac/sdio.c        | 22 +++++---
>   .../broadcom/brcm80211/brcmfmac/usb.c         |  3 ++
>   7 files changed, 61 insertions(+), 36 deletions(-)

[...]

> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c
> index e406e11481a62..f19dc7355e0e8 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c

[...]

> @@ -113,33 +118,39 @@ void brcmf_of_probe(struct device *dev, enum brcmf_bus_type bus_type,
>   		of_node_put(root);
>   	}
>   
> -	if (!np || !of_device_is_compatible(np, "brcm,bcm4329-fmac"))
> -		return;
> -
>   	err = brcmf_of_get_country_codes(dev, settings);
>   	if (err)
>   		brcmf_err("failed to get OF country code map (err=%d)\n", err);
>   
>   	of_get_mac_address(np, settings->mac);
>   
> -	if (bus_type != BRCMF_BUSTYPE_SDIO)
> -		return;
> +	if (bus_type == BRCMF_BUSTYPE_SDIO) {

Don't like the fact that this now has an extra indentation level and it 
offers no extra benefit. Just keep the original if-statement and return 
0. Consequently the LPO clock code should move just before the if-statement.

> +		if (of_property_read_u32(np, "brcm,drive-strength", &val) == 0)
> +			sdio->drive_strength = val;
>   
> -	if (of_property_read_u32(np, "brcm,drive-strength", &val) == 0)
> -		sdio->drive_strength = val;
> +		/* make sure there are interrupts defined in the node */
> +		if (!of_property_present(np, "interrupts"))
> +			return 0;
>   
> -	/* make sure there are interrupts defined in the node */
> -	if (!of_property_present(np, "interrupts"))
> -		return;
> +		irq = irq_of_parse_and_map(np, 0);
> +		if (!irq) {
> +			brcmf_err("interrupt could not be mapped\n");
> +			return 0;
> +		}
> +		irqf = irqd_get_trigger_type(irq_get_irq_data(irq));
> +
> +		sdio->oob_irq_supported = true;
> +		sdio->oob_irq_nr = irq;
> +		sdio->oob_irq_flags = irqf;
> +	}
>   
> -	irq = irq_of_parse_and_map(np, 0);
> -	if (!irq) {
> -		brcmf_err("interrupt could not be mapped\n");
> -		return;
> +	clk = devm_clk_get_optional_enabled(dev, "lpo");
> +	if (!IS_ERR_OR_NULL(clk)) {
> +		brcmf_dbg(INFO, "enabling 32kHz clock\n");
> +		return clk_set_rate(clk, 32768);
> +	} else {
> +		return PTR_ERR_OR_ZERO(clk);
>   	}

Change this to:

 > +	clk = devm_clk_get_optional_enabled(dev, "lpo");
 > +	if (IS_ERR_OR_NULL(clk)) {
 > +		return PTR_ERR_OR_ZERO(clk);
 > +	}
 > +	brcmf_dbg(INFO, "enabling 32kHz clock\n");
 > +	clk_set_rate(clk, 32768);

As said above this should be moved before the if-statement:

 > -	if (bus_type != BRCMF_BUSTYPE_SDIO)
 > -		return 0;

> -	irqf = irqd_get_trigger_type(irq_get_irq_data(irq));
>   
> -	sdio->oob_irq_supported = true;
> -	sdio->oob_irq_nr = irq;
> -	sdio->oob_irq_flags = irqf;
> +	return 0;
>   }

[...]