Re: [PATCH v4 2/3] Bluetooth: hci_qca: Add support for Qualcomm Bluetooth chip wcn3990.

[Balakrishna Godavarthi <bgodavar@codeaurora.org>]

Hi,

On 2018-05-05 06:47, Matthias Kaehlcke wrote:
> Hi,
> 
> On Fri, May 04, 2018 at 09:05:05PM +0530, Balakrishna Godavarthi wrote:
>> Add support to set voltage/current of various regulators
>> to power up/down Bluetooth chip wcn3990.
>> Add support to read baudrate from dts.
>> 
>> Signed-off-by: Balakrishna Godavarthi <bgodavar@codeaurora.org>
>> ---
>>  drivers/bluetooth/hci_qca.c | 555 
>> ++++++++++++++++++++++++++++++++++++++------
>>  1 file changed, 483 insertions(+), 72 deletions(-)
>> 
>> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
>> index f05382b..075fab7 100644
>> --- a/drivers/bluetooth/hci_qca.c
>> +++ b/drivers/bluetooth/hci_qca.c
>> @@ -5,7 +5,7 @@
>>   *  protocol extension to H4.
>>   *
>>   *  Copyright (C) 2007 Texas Instruments, Inc.
>> - *  Copyright (c) 2010, 2012 The Linux Foundation. All rights 
>> reserved.
>> + *  Copyright (c) 2010, 2012, 2018 The Linux Foundation. All rights 
>> reserved.
>>   *
>>   *  Acknowledgements:
>>   *  This file is based on hci_ll.c, which was...
>> @@ -35,6 +35,10 @@
>>  #include <linux/mod_devicetable.h>
>>  #include <linux/module.h>
>>  #include <linux/serdev.h>
>> +#include <asm-generic/delay.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/regulator/consumer.h>
>> +#include <linux/of_device.h>
> 
> AFAIK the convention is to order includes alphabetically.
> 
>> +static struct btqca_power *qca;
> 
> This limits the driver to a single instance. This is probably the most
> common use case, but in general it's preferable not to have this kind
> of limitations.
> 
>>  static void __serial_clock_on(struct tty_struct *tty)
>>  {
>>  	/* TODO: Some chipset requires to enable UART clock on client
>> @@ -463,7 +506,12 @@ static int qca_open(struct hci_uart *hu)
>>  		serdev_device_open(hu->serdev);
>> 
>>  		qcadev = serdev_device_get_drvdata(hu->serdev);
>> -		gpiod_set_value_cansleep(qcadev->bt_en, 1);
>> +		if (qcadev->btsoc_type == BTQCA_CHEROKEE) {
>> +			hu->init_speed = qcadev->init_speed;
>> +			hu->oper_speed = qcadev->oper_speed;
>> +			btqca_power_setup(true);
>> +		} else
>> +			gpiod_set_value_cansleep(qcadev->bt_en, 1);
> 
> Use curly braces for the else branch too.
> 
>> +static int qca_send_poweron_cmd(struct hci_dev *hdev)
>> +{
>> +	struct hci_uart *hu = hci_get_drvdata(hdev);
>> +	struct qca_data *qca = hu->priv;
>> +	struct sk_buff *skb;
>> +	u8 cmd;
>> +
>> +	BT_DBG("%s sending power on command to btsoc", hdev->name);
> 
> Use bt_dev_dbg(), same for other BT_XXX().
> 
>> +	/* By sending 0xFC host is trying to power up the soc */
> 
> nit: SoC, same a few lines below.
> 
>> +	cmd = CHEROKEE_POWERON_PULSE;
>> +	skb = bt_skb_alloc(sizeof(cmd), GFP_ATOMIC);
> 
> Use GFP_KERNEL, the code sleeps a few lines below, hence it must
> definitely not be called in atomic context.
> 
>> +	if (!skb) {
>> +		BT_ERR("Failed to allocate memory for skb  packet");
>> +		return -ENOMEM;
>> +	}
>> +
>> +	skb_put_data(skb, &cmd, sizeof(cmd));
>> +	hci_skb_pkt_type(skb) = HCI_COMMAND_PKT;
>> +
>> +	skb_queue_tail(&qca->txq, skb);
>> +	hci_uart_tx_wakeup(hu);
>> +
>> +	/* Wait for 100 us for soc to settle down */
>> +	set_current_state(TASK_UNINTERRUPTIBLE);
>> +	schedule_timeout(usecs_to_jiffies(100));
>> +	set_current_state(TASK_INTERRUPTIBLE);
>> +
>> +	return 0;
>> +}
>> +
>> +static int qca_send_poweroff_cmd(struct hci_dev *hdev)
>> +{
>> +	struct hci_uart *hu = hci_get_drvdata(hdev);
>> +	struct qca_data *qca = hu->priv;
>> +	struct sk_buff *skb;
>> +	u8 cmd;
>> +
>> +	BT_DBG("%s sending power off command to btsoc", hdev->name);
>> +	/* By sending 0xC0 host is trying to power off the soc */
>> +	cmd = CHEROKEE_POWEROFF_PULSE;
>> +	skb = bt_skb_alloc(sizeof(cmd), GFP_ATOMIC);
>> +	if (!skb) {
>> +		BT_ERR("Failed to allocate memory for skb  packet");
>> +		return -ENOMEM;
>> +	}
>> +
>> +	skb_put_data(skb, &cmd, sizeof(cmd));
>> +	hci_skb_pkt_type(skb) = HCI_COMMAND_PKT;
>> +
>> +	skb_queue_tail(&qca->txq, skb);
>> +	hci_uart_tx_wakeup(hu);
>> +
>> +	/* Wait for 100 us for soc to settle down */
>> +	set_current_state(TASK_UNINTERRUPTIBLE);
>> +	schedule_timeout(usecs_to_jiffies(100));
>> +	set_current_state(TASK_INTERRUPTIBLE);
>> +
>> +	return 0;
>> +}
> 
> This function is almost a clone of qca_send_poweron_cmd(), move the
> common code to something like qca_send_cmd() and call it from
> qca_send_poweron/off_cmd().
> 
>> +static int qca_serdev_open(struct hci_uart *hu)
>> +{
>> +	int ret = 0;
>> +
>> +	if (hu->serdev)
>> +		serdev_device_open(hu->serdev);
> 
> Check return value.
> 
> Add curly braces to the if branch too.
> 
>> +static int qca_serdev_close(struct hci_uart *hu)
>> +{
>> +	int ret = 0;
>> +
>> +	if (hu->serdev)
>> +		serdev_device_close(hu->serdev);
> 
> Add curly braces to the if branch too.
> 
>>  static int qca_setup(struct hci_uart *hu)
>>  {
>>  	struct hci_dev *hdev = hu->hdev;
>>  	struct qca_data *qca = hu->priv;
>> +	struct qca_serdev *qcadev;
>>  	unsigned int speed, qca_baudrate = QCA_BAUDRATE_115200;
>>  	int ret;
>> +	int soc_ver;
>> +
>> +	qcadev = serdev_device_get_drvdata(hu->serdev);
>> +
>> +	switch (qcadev->btsoc_type) {
>> +	case BTQCA_CHEROKEE:
>> +		bt_dev_info(hdev, "setting up wcn3990");
>> +		/* Patch downloading has to be done without IBS mode */
>> +		clear_bit(STATE_IN_BAND_SLEEP_ENABLED, &qca->flags);
>> +		/* Setup initial baudrate */
>> +		speed = 0;
>> +		if (hu->init_speed)
>> +			speed = hu->init_speed;
>> +		else if (hu->proto->init_speed)
>> +			speed = hu->proto->init_speed;
>> +
>> +		if (speed)
>> +			host_set_baudrate(hu, speed);
> 
> Add curly braces.
> 
>> +		else {
>> +			bt_dev_err(hdev, "initial speed %u", speed);
>> +			return -1;
>> +		}
>> 
>> -	bt_dev_info(hdev, "ROME setup");
>> +		/* disable flow control, as chip is still not turned on */
>> +		hci_uart_set_flow_control(hu, true);
> 
> The interface of this function is confusing. enable = true disables
> flow control ... Not the fault of this driver though :)
> 
>> +		/* send poweron command to btsoc */
>> +		ret = qca_send_poweron_cmd(hdev);
>> +		if (ret) {
>> +			bt_dev_err(hdev, "Failed to send power on command");
>> +			return ret;
>> +		}
>> 
>> -	/* Patch downloading has to be done without IBS mode */
>> -	clear_bit(STATE_IN_BAND_SLEEP_ENABLED, &qca->flags);
>> +		/* close serial port */
>> +		ret = qca_serdev_close(hu);
>> +		if (ret)
>> +			return ret;
>> +		/* open serial port */
>> +		ret = qca_serdev_open(hu);
>> +		if (ret)
>> +			return ret;
>> 
>> -	/* Setup initial baudrate */
>> -	speed = 0;
>> -	if (hu->init_speed)
>> -		speed = hu->init_speed;
>> -	else if (hu->proto->init_speed)
>> -		speed = hu->proto->init_speed;
>> +		/* Setup initial baudrate */
>> +		speed = 0;
>> +		if (hu->init_speed)
>> +			speed = hu->init_speed;
>> +		else if (hu->proto->init_speed)
>> +			speed = hu->proto->init_speed;
>> +		if (speed)
>> +			host_set_baudrate(hu, speed);
> 
> Add curly braces.
> 
>> +		else {
>> +			BT_ERR("%s:initial speed %u", hdev->name, speed);
>> +			return -1;
>> +		}
>> 
>> -	if (speed)
>> -		host_set_baudrate(hu, speed);
>> +		/* Enable flow control */
>> +		hci_uart_set_flow_control(hu, false);
>> +		/*  wait until flow control settled */
>> +		mdelay(100);
> 
> A busy wait of 100ms doesn't seem a good idea. Use msleep()
> instead. Is it really necessary to wait that long?
> 
>> +		bt_dev_info(hdev, "wcn3990 Patch Version Request");
>> +		ret = rome_patch_ver_req(hdev, &soc_ver);
>> +		if (ret < 0 || soc_ver == 0) {
>> +			BT_ERR("%s: Failed to get version 0x%x", hdev->name,
>> +				ret);
>> +			return ret;
>> +		}
>> 
>> -	/* Setup user speed if needed */
>> -	speed = 0;
>> -	if (hu->oper_speed)
>> -		speed = hu->oper_speed;
>> -	else if (hu->proto->oper_speed)
>> -		speed = hu->proto->oper_speed;
>> +		bt_dev_info(hdev, "wcn3990 controller version 0x%08x", soc_ver);
>> +
>> +		/* clear flow control */
>> +		hci_uart_set_flow_control(hu, true);
>> +		/* set operating speed */
>> +		speed = 0;
>> +		if (hu->oper_speed)
>> +			speed = hu->oper_speed;
>> +		else if (hu->proto->oper_speed)
>> +			speed = hu->proto->oper_speed;
>> +		if (speed) {
>> +			qca_baudrate = qca_get_baudrate_value(speed);
>> +			bt_dev_info(hdev, "Set UART speed to %d", speed);
>> +			ret = qca_set_baudrate(hdev, qca_baudrate);
>> +			if (ret) {
>> +				BT_ERR("%s:Failed to change the baud rate(%d)",
>> +					hdev->name, ret);
>> +				return ret;
>> +			}
>> +			if (speed)
>> +				host_set_baudrate(hu, speed);
> 
> Add curly braces.
> 
>> +			else {
>> +				BT_ERR("%s:Error in setting operator speed:%u",
>> +					hdev->name, speed);
>> +				return -1;
>> +			}
>> +		}
>> 
>> -	if (speed) {
>> -		qca_baudrate = qca_get_baudrate_value(speed);
>> +		/* Set flow control */
>> +		hci_uart_set_flow_control(hu, false);
>> +		/*Setup patch and  NVM configurations */
> 
> Add blank before 'Setup' and remove one before 'NVM'.
> 
>> +		ret = qca_uart_setup_cherokee(hdev, qca_baudrate, &soc_ver);
>> +		if (!ret) {
>> +			set_bit(STATE_IN_BAND_SLEEP_ENABLED, &qca->flags);
>> +			qca_debugfs_init(hdev);
>> +		} else if (ret == -ENOENT) {
>> +			/* No patch/nvm-config found, run with original
>> +			 * fw/config.
>> +			 */
>> +			ret = 0;
>> +		} else if (ret == -EAGAIN) {
>> +			/*
>> +			 * Userspace firmware loader will return -EAGAIN in
>> +			 * case no patch/nvm-config is found, so run with
>> +			 * original fw/config.
>> +			 */
>> +			ret = 0;
>> +		}
>> 
>> -		bt_dev_info(hdev, "Set UART speed to %d", speed);
>> -		ret = qca_set_baudrate(hdev, qca_baudrate);
>> -		if (ret) {
>> -			bt_dev_err(hdev, "Failed to change the baud rate (%d)",
>> -				   ret);
>> +		/* Setup wcn3990 bdaddr */
>> +		hu->hdev->set_bdaddr = qca_set_bdaddr_rome;
>> +
>> +		return ret;
>> +
>> +	default:
> 
> What follows looks similar to the Cherokee path. I didn't look at all
> the details, but it's probably possible to share some more code.
> 
>> +		bt_dev_info(hdev, "ROME setup");
>> +
>> +		/* Patch downloading has to be done without IBS mode */
>> +		clear_bit(STATE_IN_BAND_SLEEP_ENABLED, &qca->flags);
>> +
>> +		/* Setup initial baudrate */
>> +		speed = 0;
>> +		if (hu->init_speed)
>> +			speed = hu->init_speed;
>> +		else if (hu->proto->init_speed)
>> +			speed = hu->proto->init_speed;
>> +
>> +		if (speed)
>> +			host_set_baudrate(hu, speed);
>> +
>> +		/* Setup user speed if needed */
>> +		speed = 0;
>> +		if (hu->oper_speed)
>> +			speed = hu->oper_speed;
>> +		else if (hu->proto->oper_speed)
>> +			speed = hu->proto->oper_speed;
>> +
>> +		if (speed) {
>> +			qca_baudrate = qca_get_baudrate_value(speed);
>> +
>> +			bt_dev_info(hdev, "Set UART speed to %d", speed);
>> +			ret = qca_set_baudrate(hdev, qca_baudrate);
>> +			if (ret) {
>> +				bt_dev_err(hdev, "Failed to change the baud rate (%d)",
>> +					   ret);
>>  			return ret;
> 
> Fix indentation.
> 
>> +static const struct btqca_vreg_data cherokee_data = {
>> +	.soc_type = BTQCA_CHEROKEE,
>> +	.vregs = (struct btqca_vreg []) {
>> +		{ "vddio",   1352000, 1352000,  0 },
>> +		{ "vddxtal", 1904000, 2040000,  0 },
>> +		{ "vddcore", 1800000, 1800000,  1 },
>> +		{ "vddpa",   130400,  1304000,  1 },
> 
> 0 missing for min_v?
> 
>> +		{ "vddldo",  3000000, 3312000,  1 },
>> +	},
>> +	.num_vregs = 5,
>> +};
>> +
>> +void btqca_disable_regulators(int reg_nu, struct btqca_vreg *vregs)
>> +{
>> +	/* disable the regulator if requested by user
>> +	 * or when fault in any regulator.
>> +	 */
>> +	for (reg_nu = reg_nu - 1; reg_nu >= 0 ; reg_nu--) {
> 
> Better use a local variable for iteration instead of the function 
> parameter
> 
>> +int btqca_power_setup(bool on)
>> +{
>> +	int ret = 0;
>> +	int i;
>> +	struct btqca_vreg *vregs;
>> +
>> +	if (!qca || !qca->vreg_data || !qca->vreg_bulk)
>> +		return -EINVAL;
>> +	vregs = qca->vreg_data->vregs;
>> +
>> +	BT_DBG("on: %d", on);
>> +	/* turn on if regualtors are off */
>> +	if (on == true && qca->vreg_status == false) {
> 
> if (on && !qca->vreg_status)
> 
> You might also consider a more expressive name instead of vreg_status,
> something like vregs_on.
> 
>> +		qca->vreg_status = true;
>> +		for (i = 0; ret == 0 && i < qca->vreg_data->num_vregs; i++) {
> 
> Better check ret inline and break when an error is encountered
> 
>> +			regulator_set_voltage(qca->vreg_bulk[i].consumer,
>> +					      vregs[i].min_v,
>> +					      vregs[i].max_v);
> 
> Check return value.
> 
>> +
>> +			if (vregs[i].load_ua)
>> +				regulator_set_load(qca->vreg_bulk[i].consumer,
>> +						   vregs[i].load_ua);
> 
> Check return value.
> 
>> +			ret = regulator_enable(qca->vreg_bulk[i].consumer);
>> +	}
> 
> Fix indentation.
> 
>> +	} else if (on == false && qca->vreg_status == true) {
> 
> (!on && qca->vreg_status)
> 
>> +		qca->vreg_status = false;
>> +		/* turn of regualtor in reverse order */
> 
> 'off, regulator'
> 
>> +		btqca_disable_regulators(qca->vreg_data->num_vregs, vregs);
>> +	}
>> +
>> +	/* regulatos fails to enable */
> 
> 'regulators failed'
> 
>> +	if (ret) {
>> +		qca->vreg_status = false;
>> +		BT_ERR("failed to enable regualtor:%s", vregs[i].name);
> 
> 'regulator'
> 
>> +		/* set regulator voltage and load to zero */
>> +		regulator_set_voltage(qca->vreg_bulk[i].consumer,
>> +				      0, vregs[i].max_v);
> 
> check return value.
> 
>>  static int qca_serdev_probe(struct serdev_device *serdev)
>>  {
>>  	struct qca_serdev *qcadev;
>> -	int err;
>> +	const struct btqca_vreg_data *data;
>> +	int err = 0;
>> 
>>  	qcadev = devm_kzalloc(&serdev->dev, sizeof(*qcadev), GFP_KERNEL);
>>  	if (!qcadev)
>>  		return -ENOMEM;
>> 
>>  	qcadev->serdev_hu.serdev = serdev;
>> +	data = of_device_get_match_data(&serdev->dev);
>> +	if (data && data->soc_type == BTQCA_CHEROKEE)
>> +		qcadev->btsoc_type = BTQCA_CHEROKEE;
>> +	else
>> +		qcadev->btsoc_type = BTQCA_ROME;
>> +
>>  	serdev_device_set_drvdata(serdev, qcadev);
>> +	if (qcadev->btsoc_type == BTQCA_CHEROKEE) {
>> +		qca = kzalloc(sizeof(struct btqca_power), GFP_KERNEL);
> 
> Use devm_kzalloc()
> 
>> +		if (!qca)
>> +			return -ENOMEM;
>> +
>> +		qca->dev = &serdev->dev;
>> +		qca->vreg_data = data;
>> +		err = init_regulators(qca, data->vregs, data->num_vregs);
>> +		if (err) {
>> +			BT_ERR("Failed to init regualtors:%d", err);
> 
> 'regulators'
> 
>> +			kfree(qca);
>> +			goto out;
>> +		}
>> 
>> -	qcadev->bt_en = devm_gpiod_get(&serdev->dev, "enable",
>> -				       GPIOD_OUT_LOW);
>> -	if (IS_ERR(qcadev->bt_en)) {
>> -		dev_err(&serdev->dev, "failed to acquire enable gpio\n");
>> -		return PTR_ERR(qcadev->bt_en);
>> -	}
>> +		/* set voltage regulator status as false */
>> +		qca->vreg_status = false;
>> +		/* get operating speed */
>> +		device_property_read_u32(&serdev->dev, "oper-speed",
>> +					 &qcadev->oper_speed);
>> +		device_property_read_u32(&serdev->dev, "init-speed",
>> +					 &qcadev->init_speed);
>> +		if (!qcadev->oper_speed)
>> +			BT_INFO("DTS entry for operating speed is
>> -				       disabled");
> 
> The message isn't very clear. The entry isn't disabled, it doesn't 
> exist.
> 
>>  static void qca_serdev_remove(struct serdev_device *serdev)
>> @@ -1047,12 +1454,16 @@ static void qca_serdev_remove(struct 
>> serdev_device *serdev)
>>  	struct qca_serdev *qcadev = serdev_device_get_drvdata(serdev);
>> 
>>  	hci_uart_unregister_device(&qcadev->serdev_hu);
>> -
>> -	clk_disable_unprepare(qcadev->susclk);
>> +	if (qcadev->btsoc_type == BTQCA_CHEROKEE) {
>> +		btqca_power_setup(false);
>> +		kfree(qca);
>> +	} else
>> +		clk_disable_unprepare(qcadev->susclk);
> 
> Add curly braces.

will send a incremental patches as per your comments.

-- 
Regards
Balakrishna.