Re: [PATCH v3 1/2] Bluetooth: hci_qca: Added support for wcn3998

From: Matthias Kaehlcke <mka@chromium.org>
To: Harish Bandi <c-hbandi@codeaurora.org>
Cc: marcel@holtmann.org, johan.hedberg@gmail.com,
	linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org,
	hemantg@codeaurora.org, linux-arm-msm@vger.kernel.org,
	bgodavar@codeaurora.org, anubhavg@codeaurora.org
Subject: Re: [PATCH v3 1/2] Bluetooth: hci_qca: Added support for wcn3998
Date: Tue, 12 Mar 2019 09:29:47 -0700	[thread overview]
Message-ID: <20190312162947.GC200579@google.com> (raw)
In-Reply-To: <1552393379-26330-2-git-send-email-c-hbandi@codeaurora.org>

Hi Harish,

On Tue, Mar 12, 2019 at 05:52:58PM +0530, Harish Bandi wrote:
> Added new compatible for wcn3998 and corresponding voltage
> and current values to wcn3998 compatible.
> Changed driver code to support wcn3998
> 
> Signed-off-by: Harish Bandi <c-hbandi@codeaurora.org>
> ---
> changes in v3:
> - updated to latest code base.

This is not useful, for future versions please describe what changed
(e.g. 'specify regulator constraints in the driver instead of the DT')

> ---
>  drivers/bluetooth/btqca.c   |  4 ++--
>  drivers/bluetooth/btqca.h   |  3 ++-
>  drivers/bluetooth/hci_qca.c | 40 ++++++++++++++++++++++++++--------------
>  3 files changed, 30 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/bluetooth/btqca.c b/drivers/bluetooth/btqca.c
> index 6122685..70cab13 100644
> --- a/drivers/bluetooth/btqca.c
> +++ b/drivers/bluetooth/btqca.c
> @@ -344,7 +344,7 @@ int qca_uart_setup(struct hci_dev *hdev, uint8_t baudrate,
>  
>  	/* Download rampatch file */
>  	config.type = TLV_TYPE_PATCH;
> -	if (soc_type == QCA_WCN3990) {
> +	if (soc_type >= QCA_WCN3990) {

That works, but isn't super-clear and might need to be adapted when
future non-WCN399x controllers are added.

Some possible alternatives:

- is_wcn399x(soc_type)
- have a family (Rome, Cherokee (IIRC this name was used for WCN3990))
  and a chip id (QCA6174, WCN3990, WCN3998, ...)

>  		/* Firmware files to download are based on ROM version.
>  		 * ROM version is derived from last two bytes of soc_ver.
>  		 */
> @@ -365,7 +365,7 @@ int qca_uart_setup(struct hci_dev *hdev, uint8_t baudrate,
>  
>  	/* Download NVM configuration */
>  	config.type = TLV_TYPE_NVM;
> -	if (soc_type == QCA_WCN3990)
> +	if (soc_type >= QCA_WCN3990)
>  		snprintf(config.fwname, sizeof(config.fwname),
>  			 "qca/crnv%02x.bin", rom_ver);
>  	else
> diff --git a/drivers/bluetooth/btqca.h b/drivers/bluetooth/btqca.h
> index c72c56e..f03d96e 100644
> --- a/drivers/bluetooth/btqca.h
> +++ b/drivers/bluetooth/btqca.h
> @@ -132,7 +132,8 @@ enum qca_btsoc_type {
>  	QCA_INVALID = -1,
>  	QCA_AR3002,
>  	QCA_ROME,
> -	QCA_WCN3990
> +	QCA_WCN3990,
> +	QCA_WCN3998

nit: if you add a comma after the last value the line doesn't need to
be changed when a new type is added in the future.

Is 'WCN3998' specific enough? You mentioned earlier that there are
multiple WCN3998 variants with different requirements for regulator
voltages/max currents. Which names does Qualcomm use to distinguish
between them (e.g. WCN3998-A, WCN3998-B, ...)?

Thanks

Matthias