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

[Matthias Kaehlcke <mka@chromium.org>]

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.