linux-kernel - Re: [PATCH] NFC: trf7970a: Correct register settings for 27MHz clock

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20170426170443.GB11522@animalcreek.com>
Date:   Wed, 26 Apr 2017 10:04:43 -0700
From:   Mark Greer <mgreer@...malcreek.com>
To:     Geoff Lansberry <geoff@...ee.com>, g@...malcreek.com
Cc:     linux-wireless@...r.kernel.org, sameo@...ux.intel.com,
        kernel-janitors@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-nfc@...ts.01.org, devicetree@...r.kernel.org,
        mgreer@...malcreek.com, justin@...ee.com, colin.king@...onical.com
Subject: Re: [PATCH] NFC: trf7970a: Correct register settings for 27MHz clock

On Wed, Apr 26, 2017 at 09:48:33AM -0400, Geoff Lansberry wrote:
> In prior commits the selected clock frequency does not propagate
> correctly to what is written the the TRF7970A_MODULATOR_SYS_CLK_CTRL
> register.
> Also fixes a bug that causes the device tree property check to always
> pass.
> 
> Signed-off-by: Geoff Lansberry <geoff@...ee.com>
> ---
>  drivers/nfc/trf7970a.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c
> index 2d1c8ca..c278b0e 100644
> --- a/drivers/nfc/trf7970a.c
> +++ b/drivers/nfc/trf7970a.c
> @@ -2071,7 +2071,7 @@ static int trf7970a_probe(struct spi_device *spi)
>  	}
>  
>  	of_property_read_u32(np, "clock-frequency", &clk_freq);
> -	if ((clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY) ||
> +	if ((clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY) &&

There is already a patch submitted to fix this issue so no need to fix
it again.  For the record, it should have been in a separate patch
since it fixes a different issue than what is fixed below.

>  		(clk_freq != TRF7970A_13MHZ_CLOCK_FREQUENCY)) {
>  		dev_err(trf->dev,
>  			"clock-frequency (%u Hz) unsupported\n",
> @@ -2079,6 +2079,13 @@ static int trf7970a_probe(struct spi_device *spi)
>  		return -EINVAL;
>  	}
>  
> +	if (clk_freq == TRF7970A_27MHZ_CLOCK_FREQUENCY) {
> +		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_27MHZ;
> +		dev_dbg(trf->dev, "trf7970a configured for 27MHz crystal\n");
> +	} else {
> +		trf->modulator_sys_clk_ctrl = 0;
> +	}
> +
>  	if (of_property_read_bool(np, "en2-rf-quirk"))
>  		trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;

This part looks okay to me but I like Walter's suggestion too.

Mark
--