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Subject: Re: [PATCH v1 3/3] Bluetooth: hci_qca: Add support for QTI bluetooth
 MAPLE
From:   Marcel Holtmann <marcel@holtmann.org>
In-Reply-To: <YYD1PJrFw/xmEXIW@kroah.com>
Date:   Tue, 2 Nov 2021 09:38:29 +0100
Cc:     Zijun Hu <zijuhu@codeaurora.org>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-bluetooth <linux-bluetooth@vger.kernel.org>,
        MSM <linux-arm-msm@vger.kernel.org>,
        Balakrishna Godavarthi <bgodavar@codeaurora.org>,
        c-hbandi@codeaurora.org, Hemantg <hemantg@codeaurora.org>,
        Matthias Kaehlcke <mka@chromium.org>,
        Rocky Liao <rjliao@codeaurora.org>,
        Zijun Hu <quic_zijuhu@quicinc.com>
Content-Transfer-Encoding: 8BIT
Message-Id: <432B905E-5263-47A6-95AA-7F43715BE196@holtmann.org>
References: <1635837177-1341-1-git-send-email-zijuhu@codeaurora.org>
 <YYDqW6ewycWP1Y7a@kroah.com>
 <4f6aee28-4d86-116c-6c47-bfce5de6551b@codeaurora.org>
 <YYD1PJrFw/xmEXIW@kroah.com>
To:     Greg KH <gregkh@linuxfoundation.org>
Precedence: bulk

Hi Greg,

>>>> Add support for MAPLE integrated within SOC, it is mounted on
>>>> a virtual tty port and powered on/off via relevant IOCTL, neither
>>>> IBS nor RAMPATCH downloading is not required.
>>>> 
>>>> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
>>>> ---
>>>> drivers/bluetooth/btqca.c   | 13 ++++++++++++-
>>>> drivers/bluetooth/btqca.h   | 13 +++++++++++++
>>>> drivers/bluetooth/hci_qca.c | 47 ++++++++++++++++++++++++++++++++++++++++++++-
>>>> 3 files changed, 71 insertions(+), 2 deletions(-)
>>>> 
>>>> diff --git a/drivers/bluetooth/btqca.c b/drivers/bluetooth/btqca.c
>>>> index be04d74037d2..b83d2ecefe5d 100644
>>>> --- a/drivers/bluetooth/btqca.c
>>>> +++ b/drivers/bluetooth/btqca.c
>>>> @@ -255,6 +255,8 @@ static void qca_tlv_check_data(struct hci_dev *hdev,
>>>> 		BT_DBG("TLV Type\t\t : 0x%x", type_len & 0x000000ff);
>>>> 		BT_DBG("Length\t\t : %d bytes", length);
>>>> 
>>>> +		if (qca_is_maple(soc_type))
>>>> +			break;
>>>> 		idx = 0;
>>>> 		data = tlv->data;
>>>> 		while (idx < length) {
>>>> @@ -552,6 +554,9 @@ int qca_uart_setup(struct hci_dev *hdev, uint8_t baudrate,
>>>> 	rom_ver = ((soc_ver & 0x00000f00) >> 0x04) | (soc_ver & 0x0000000f);
>>>> 
>>>> 	/* Download rampatch file */
>>>> +	if (qca_is_maple(soc_type))
>>>> +		goto download_nvm;
>>>> +
>>>> 	config.type = TLV_TYPE_PATCH;
>>>> 	if (qca_is_wcn399x(soc_type)) {
>>>> 		snprintf(config.fwname, sizeof(config.fwname),
>>>> @@ -580,6 +585,7 @@ int qca_uart_setup(struct hci_dev *hdev, uint8_t baudrate,
>>>> 	/* Give the controller some time to get ready to receive the NVM */
>>>> 	msleep(10);
>>>> 
>>>> +download_nvm:
>>>> 	/* Download NVM configuration */
>>>> 	config.type = TLV_TYPE_NVM;
>>>> 	if (firmware_name)
>>>> @@ -597,6 +603,9 @@ int qca_uart_setup(struct hci_dev *hdev, uint8_t baudrate,
>>>> 	else if (soc_type == QCA_QCA6390)
>>>> 		snprintf(config.fwname, sizeof(config.fwname),
>>>> 			 "qca/htnv%02x.bin", rom_ver);
>>>> +	else if (qca_is_maple(soc_type))
>>>> +		snprintf(config.fwname, sizeof(config.fwname),
>>>> +			 "qca/mpnv%02x.bin", rom_ver);
>>>> 	else if (soc_type == QCA_WCN6750)
>>>> 		snprintf(config.fwname, sizeof(config.fwname),
>>>> 			 "qca/msnv%02x.bin", rom_ver);
>>>> @@ -609,6 +618,8 @@ int qca_uart_setup(struct hci_dev *hdev, uint8_t baudrate,
>>>> 		bt_dev_err(hdev, "QCA Failed to download NVM (%d)", err);
>>>> 		return err;
>>>> 	}
>>>> +	if (qca_is_maple(soc_type))
>>>> +		msleep(MAPLE_NVM_READY_DELAY_MS);
>>>> 
>>>> 	if (soc_type >= QCA_WCN3991) {
>>>> 		err = qca_disable_soc_logging(hdev);
>>>> @@ -637,7 +648,7 @@ int qca_uart_setup(struct hci_dev *hdev, uint8_t baudrate,
>>>> 		return err;
>>>> 	}
>>>> 
>>>> -	if (soc_type == QCA_WCN3991 || soc_type == QCA_WCN6750) {
>>>> +	if (soc_type == QCA_WCN3991 || soc_type == QCA_WCN6750 || qca_is_maple(soc_type)) {
>>>> 		/* get fw build info */
>>>> 		err = qca_read_fw_build_info(hdev);
>>>> 		if (err < 0)
>>>> diff --git a/drivers/bluetooth/btqca.h b/drivers/bluetooth/btqca.h
>>>> index 30afa7703afd..0a5a7d1daa71 100644
>>>> --- a/drivers/bluetooth/btqca.h
>>>> +++ b/drivers/bluetooth/btqca.h
>>>> @@ -46,6 +46,8 @@
>>>> 
>>>> #define QCA_FW_BUILD_VER_LEN		255
>>>> 
>>>> +#define MAPLE_NVM_READY_DELAY_MS        1500
>>>> +#define MAPLE_POWER_CONTROL_DELAY_MS    50
>>>> 
>>>> enum qca_baudrate {
>>>> 	QCA_BAUDRATE_115200 	= 0,
>>>> @@ -145,6 +147,7 @@ enum qca_btsoc_type {
>>>> 	QCA_WCN3991,
>>>> 	QCA_QCA6390,
>>>> 	QCA_WCN6750,
>>>> +	QCA_MAPLE,
>>>> };
>>>> 
>>>> #if IS_ENABLED(CONFIG_BT_QCA)
>>>> @@ -167,6 +170,11 @@ static inline bool qca_is_wcn6750(enum qca_btsoc_type soc_type)
>>>> 	return soc_type == QCA_WCN6750;
>>>> }
>>>> 
>>>> +static inline bool qca_is_maple(enum qca_btsoc_type soc_type)
>>>> +{
>>>> +	return soc_type == QCA_MAPLE;
>>>> +}
>>>> +
>>>> #else
>>>> 
>>>> static inline int qca_set_bdaddr_rome(struct hci_dev *hdev, const bdaddr_t *bdaddr)
>>>> @@ -204,6 +212,11 @@ static inline bool qca_is_wcn6750(enum qca_btsoc_type soc_type)
>>>> 	return false;
>>>> }
>>>> 
>>>> +static inline bool qca_is_maple(enum qca_btsoc_type soc_type)
>>>> +{
>>>> +	return false;
>>>> +}
>>>> +
>>>> static inline int qca_send_pre_shutdown_cmd(struct hci_dev *hdev)
>>>> {
>>>> 	return -EOPNOTSUPP;
>>>> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
>>>> index dd768a8ed7cb..f1d9670719c4 100644
>>>> --- a/drivers/bluetooth/hci_qca.c
>>>> +++ b/drivers/bluetooth/hci_qca.c
>>>> @@ -70,6 +70,10 @@
>>>> #define QCA_CRASHBYTE_PACKET_LEN	1096
>>>> #define QCA_MEMDUMP_BYTE		0xFB
>>>> 
>>>> +#ifndef IOCTL_IPC_BOOT
>>>> +#define IOCTL_IPC_BOOT                  0xBE
>>>> +#endif
>>> 
>>> You send this command, but never use it.  Where is the driver code that
>>> uses this command?
>>> 
>> qca_maple_power_control() will use it.  this driver depends on bt_tty kernel module
>> https://source.codeaurora.org/quic/qsdk/oss/kernel/linux-ipq-5.4/tree/drivers/soc/qcom/bt_tty.c?h=NHSS.QSDK.11.5.0.5.r2
> 
> You can not add code to the kernel that is not used by the kernel
> itself.  That driver needs to be in the tree as well, why is it not
> submitted now too?
> 
>>> And why not tabs?
>>> 
>>> And why is this patch series not properly threaded so tools can pick it
>>> up and find them?
>>> 
>>> And why the odd named ioctl that is different from other ones in this
>>> file?
>>> 
>> that IOCTL name is defined by that module.
>> https://source.codeaurora.org/quic/qsdk/oss/kernel/linux-ipq-5.4/tree/include/linux/bt.h?h=NHSS.QSDK.11.5.0.5.r2
> 
> Again, it needs to be in the tree.
> 
>>> And why not just use normal power management hooks for doing things like
>>> turning on and off the hardware like all other drivers?
>>> 
>> this device is special.
> 
> All drivers and devices are special and unique.  Just like all of them :)
> 
> What is so odd about this device that it can not work with the existing
> infrastructure that the kernel has for all of the hundreds of thousands
> of other devices it supports?
> 
>> it seems BT maintainer decides to drop this patch.
> 
> Of course, at the very least because there is no in-kernel user, why
> would you accept such a patch if you were the maintainer?
> 
> Please submit your driver first.

this power on via ioctl is nasty business. I am so happy that we got rid of
the crucks when we finally landed serdev.

Some people are working on power sequence support and alike. This needs to
use proper infrastructure or extend existing infrastructure. To fit the
needs.

I am just 100% certain, that booting an IPC via an ioctl isn’t it. We
really suffered through it in the 2.4 kernel days. The hardware needs to
be described properly in device tree and the kernel needs to take all
the appropriate actions if a Bluetooth device is powered on via its
standard power on procedure. And that is through bluetoothd (or if you
use some other Bluetooth userspace) via the exposed API from the kernel.

Regards

Marcel