Re: [PATCH v9 7/7] Bluetooth: hci_qca: Add support for Qualcomm Bluetooth chip wcn3990

[Balakrishna Godavarthi <bgodavar@codeaurora.org>]

Hi Matthias,

On 2018-07-07 03:51, Matthias Kaehlcke wrote:
> On Thu, Jul 05, 2018 at 10:25:15PM +0530, Balakrishna Godavarthi wrote:
>> Add support to set voltage/current of various regulators
>> to power up/down Bluetooth chip wcn3990.
>> 
>> Signed-off-by: Balakrishna Godavarthi <bgodavar@codeaurora.org>
>> ---
>> changes in v9:
>>     * moved flow control to vendor and set_baudarte functions.
>>     * removed parent regs.
>> 
>> changes in v8:
>>     * closing qca buffer, if qca_power_setup fails
>>     * chnaged ibs start timer function call location.
>>     * updated review comments.
>> 
>> changes in v7:
>>     * addressed review comments.
>> 
>> changes in v6:
>>     * Hooked up qca_power to qca_serdev.
>>     * renamed all the naming inconsistency functions with qca_*
>>     * leveraged common code of ROME for wcn3990.
>>     * created wrapper functions for re-usable blocks.
>>     * updated function of _*regulator_enable and _*regualtor_disable.
>>     * removed redundant comments and functions.
>>     * addressed review comments.
>> 
>> Changes in v5:
>>     * updated regulator vddpa min_uV to 1304000.
>>       * addressed review comments.
>> 
>> Changes in v4:
>>     * Segregated the changes of btqca from hci_qca
>>     * rebased all changes on top of bluetooth-next.
>>     * addressed review comments.
>> 
>> ---
>>  drivers/bluetooth/btqca.h   |   3 +
>>  drivers/bluetooth/hci_qca.c | 387 
>> +++++++++++++++++++++++++++++++-----
>>  2 files changed, 345 insertions(+), 45 deletions(-)
>> 
>> diff --git a/drivers/bluetooth/btqca.h b/drivers/bluetooth/btqca.h
>> index a9c2779f3e07..0c01f375fe83 100644
>> --- a/drivers/bluetooth/btqca.h
>> +++ b/drivers/bluetooth/btqca.h
>> @@ -37,6 +37,9 @@
>>  #define EDL_TAG_ID_HCI			(17)
>>  #define EDL_TAG_ID_DEEP_SLEEP		(27)
>> 
>> +#define QCA_WCN3990_POWERON_PULSE	0xFC
>> +#define QCA_WCN3990_POWEROFF_PULSE	0xC0
>> +
>>  enum qca_bardrate {
>>  	QCA_BAUDRATE_115200 	= 0,
>>  	QCA_BAUDRATE_57600,
>> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
>> index 7ebfaa0edf3f..d62c7785a618 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...
>> @@ -31,9 +31,14 @@
>>  #include <linux/kernel.h>
>>  #include <linux/clk.h>
>>  #include <linux/debugfs.h>
>> +#include <linux/delay.h>
>> +#include <linux/device.h>
>>  #include <linux/gpio/consumer.h>
>>  #include <linux/mod_devicetable.h>
>>  #include <linux/module.h>
>> +#include <linux/of_device.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/regulator/consumer.h>
>>  #include <linux/serdev.h>
>> 
>>  #include <net/bluetooth/bluetooth.h>
>> @@ -124,12 +129,46 @@ enum qca_speed_type {
>>  	QCA_OPER_SPEED
>>  };
>> 
>> +/*
>> + * Voltage regulator information required for configuring the
>> + * QCA Bluetooth chipset
>> + */
>> +struct qca_vreg {
>> +	const char *name;
>> +	unsigned int min_uV;
>> +	unsigned int max_uV;
>> +	unsigned int load_uA;
>> +};
>> +
>> +struct qca_vreg_data {
>> +	enum qca_btsoc_type soc_type;
>> +	struct qca_vreg *vregs;
>> +	size_t num_vregs;
>> +};
>> +
>> +/*
>> + * Platform data for the QCA Bluetooth power driver.
>> + */
>> +struct qca_power {
>> +	struct device *dev;
>> +	const struct qca_vreg_data *vreg_data;
>> +	struct regulator_bulk_data *vreg_bulk;
>> +	bool vregs_on;
>> +};
>> +
>>  struct qca_serdev {
>>  	struct hci_uart	 serdev_hu;
>>  	struct gpio_desc *bt_en;
>>  	struct clk	 *susclk;
>> +	enum qca_btsoc_type btsoc_type;
>> +	struct qca_power *bt_power;
>> +	u32 init_speed;
>> +	u32 oper_speed;
>>  };
>> 
>> +static int qca_power_setup(struct hci_uart *hu, bool on);
>> +static void qca_power_shutdown(struct hci_uart *hu);
>> +
>>  static void __serial_clock_on(struct tty_struct *tty)
>>  {
>>  	/* TODO: Some chipset requires to enable UART clock on client
>> @@ -407,6 +446,7 @@ static int qca_open(struct hci_uart *hu)
>>  {
>>  	struct qca_serdev *qcadev;
>>  	struct qca_data *qca;
>> +	int ret;
>> 
>>  	BT_DBG("hu %p qca_open", hu);
>> 
>> @@ -458,19 +498,32 @@ static int qca_open(struct hci_uart *hu)
>> 
>>  	hu->priv = qca;
>> 
>> -	timer_setup(&qca->wake_retrans_timer, hci_ibs_wake_retrans_timeout, 
>> 0);
>> -	qca->wake_retrans = IBS_WAKE_RETRANS_TIMEOUT_MS;
>> -
>> -	timer_setup(&qca->tx_idle_timer, hci_ibs_tx_idle_timeout, 0);
>> -	qca->tx_idle_delay = IBS_TX_IDLE_TIMEOUT_MS;
>> -
>>  	if (hu->serdev) {
>>  		serdev_device_open(hu->serdev);
>> 
>>  		qcadev = serdev_device_get_drvdata(hu->serdev);
>> -		gpiod_set_value_cansleep(qcadev->bt_en, 1);
>> +		if (qcadev->btsoc_type != QCA_WCN3990) {
>> +			gpiod_set_value_cansleep(qcadev->bt_en, 1);
>> +		} else {
>> +			hu->init_speed = qcadev->init_speed;
>> +			hu->oper_speed = qcadev->oper_speed;
>> +			ret = qca_power_setup(hu, true);
>> +			if (ret) {
>> +				destroy_workqueue(qca->workqueue);
>> +				kfree_skb(qca->rx_skb);
>> +				hu->priv = NULL;
>> +				kfree(qca);
>> +				return ret;
>> +			}
>> +		}
>>  	}
>> 
>> +	timer_setup(&qca->wake_retrans_timer, hci_ibs_wake_retrans_timeout, 
>> 0);
>> +	qca->wake_retrans = IBS_WAKE_RETRANS_TIMEOUT_MS;
>> +
>> +	timer_setup(&qca->tx_idle_timer, hci_ibs_tx_idle_timeout, 0);
>> +	qca->tx_idle_delay = IBS_TX_IDLE_TIMEOUT_MS;
>> +
>>  	BT_DBG("HCI_UART_QCA open, tx_idle_delay=%u, wake_retrans=%u",
>>  	       qca->tx_idle_delay, qca->wake_retrans);
>> 
>> @@ -554,10 +607,13 @@ static int qca_close(struct hci_uart *hu)
>>  	qca->hu = NULL;
>> 
>>  	if (hu->serdev) {
>> -		serdev_device_close(hu->serdev);
>> -
>>  		qcadev = serdev_device_get_drvdata(hu->serdev);
>> -		gpiod_set_value_cansleep(qcadev->bt_en, 0);
>> +		if (qcadev->btsoc_type == QCA_WCN3990)
>> +			qca_power_shutdown(hu);
>> +		else
>> +			gpiod_set_value_cansleep(qcadev->bt_en, 0);
>> +
>> +		serdev_device_close(hu->serdev);
>>  	}
>> 
>>  	kfree_skb(qca->rx_skb);
>> @@ -891,6 +947,7 @@ static int qca_set_baudrate(struct hci_dev *hdev, 
>> uint8_t baudrate)
>>  	struct hci_uart *hu = hci_get_drvdata(hdev);
>>  	struct qca_data *qca = hu->priv;
>>  	struct sk_buff *skb;
>> +	struct qca_serdev *qcadev;
>>  	u8 cmd[] = { 0x01, 0x48, 0xFC, 0x01, 0x00 };
>> 
>>  	if (baudrate > QCA_BAUDRATE_3200000)
>> @@ -904,6 +961,13 @@ static int qca_set_baudrate(struct hci_dev *hdev, 
>> uint8_t baudrate)
>>  		return -ENOMEM;
>>  	}
>> 
>> +	/* Disabling hardware flow control is mandate while
> 
> nit: s/mandate/mandatory|required/
> 
>> +	 * sending change baudrate request to wcn3990 SoC.
>> +	 */
>> +	qcadev = serdev_device_get_drvdata(hu->serdev);
>> +	if (qcadev->btsoc_type == QCA_WCN3990)
>> +		hci_uart_set_flow_control(hu, true);
>> +
>>  	/* Assign commands to change baudrate and packet type. */
>>  	skb_put_data(skb, cmd, sizeof(cmd));
>>  	hci_skb_pkt_type(skb) = HCI_COMMAND_PKT;
>> @@ -919,6 +983,9 @@ static int qca_set_baudrate(struct hci_dev *hdev, 
>> uint8_t baudrate)
>>  	schedule_timeout(msecs_to_jiffies(BAUDRATE_SETTLE_TIMEOUT_MS));
>>  	set_current_state(TASK_RUNNING);
>> 
>> +	if (qcadev->btsoc_type == QCA_WCN3990)
>> +		hci_uart_set_flow_control(hu, false);
>> +
>>  	return 0;
>>  }
>> 
>> @@ -930,6 +997,36 @@ static inline void host_set_baudrate(struct 
>> hci_uart *hu, unsigned int speed)
>>  		hci_uart_set_baudrate(hu, speed);
>>  }
>> 
>> +static int qca_send_vendor_cmd(struct hci_dev *hdev, u8 cmd)
>> +{
>> +	struct hci_uart *hu = hci_get_drvdata(hdev);
>> +	struct qca_data *qca = hu->priv;
>> +	struct sk_buff *skb;
>> +
>> +	bt_dev_dbg(hdev, "sending command %02x to SoC", cmd);
>> +
>> +	skb = bt_skb_alloc(sizeof(cmd), GFP_KERNEL);
>> +	if (!skb)
>> +		return -ENOMEM;
>> +
>> +	/* Disabling hardware flow control is mandate while
> 
> Same nit as above
> 
>> +	 * sending vendor power on and off pulse to SoC.
>> +	 */
> 
> The function is called qca_send_vendor_cmd(), the comment about power
> on/off pulses seems misplaced here. Are there other 'vendor commands'
> that require a different flow control behavior?
> 
> Perhaps the function should have a different name or we need another
> wrapper.
> 
>> +	hci_uart_set_flow_control(hu, true);
> 
> Should the changing of the flow control be limited to wcn3990? As of
> now the function is only called for wcn3990, however this is not
> stated as a requirement and might change in the future.
> 
>> +	skb_put_u8(skb, 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 */
>> +	usleep_range(100, 200);
> 
> Is this needed for any 'vendor command' or directly related with the
> power on/off pulses?
> 
>> +	hci_uart_set_flow_control(hu, false);
>> +
>> +	return 0;
>> +}
>> +
>>  static unsigned int qca_get_speed(struct hci_uart *hu,
>>  				  enum qca_speed_type speed_type)
>>  {
>> @@ -952,10 +1049,19 @@ static unsigned int qca_get_speed(struct 
>> hci_uart *hu,
>> 
>>  static int qca_check_speeds(struct hci_uart *hu)
>>  {
>> -	/* One or the other speeds should be non zero. */
>> -	if (!qca_get_speed(hu, QCA_INIT_SPEED) &&
>> -	    !qca_get_speed(hu, QCA_OPER_SPEED))
>> +	struct qca_serdev *qcadev;
>> +
>> +	qcadev = serdev_device_get_drvdata(hu->serdev);
>> +	if ((qcadev->btsoc_type == QCA_WCN3990 &&
>> +	    !qca_get_speed(hu, QCA_INIT_SPEED)) ||
>> +	    !qca_get_speed(hu, QCA_OPER_SPEED)) {
>> +		/* Both INIT and OPER speed should be non zero. */
>>  		return -EINVAL;
>> +	} else if (!qca_get_speed(hu, QCA_INIT_SPEED) &&
>> +		    !qca_get_speed(hu, QCA_OPER_SPEED)) {
>> +		/* One or the other speeds should be non zero. */
>> +		return -EINVAL;
>> +	}
> 
> It is questionable if the comments are useful, they are basically
> stating the same as the conditions.
> 
> if-else statements with a single statement in all branches shouldn't
> use curly braces. Personally I don't dislike them in this case with
> the multi-line conditions, but in principle they shoulnd't be there.
> 
> nit: this would be easier to read with nested if statements:
> 
> 	if (qcadev->btsoc_type == QCA_WCN3990)
> 		if (!qca_get_speed(hu, QCA_INIT_SPEED)) ||
> 		    !qca_get_speed(hu, QCA_OPER_SPEED))
> 			return -EINVAL;
> 	else
> 		if (!qca_get_speed(hu, QCA_INIT_SPEED) &&
> 		    !qca_get_speed(hu, QCA_OPER_SPEED)) {
> 			return -EINVAL;
> 
>>  	return 0;
>>  }
>> @@ -986,15 +1092,40 @@ static int qca_set_speed(struct hci_uart *hu, 
>> enum qca_speed_type speed_type)
>>  	return 0;
>>  }
>> 
>> +static int qca_wcn3990_init(struct hci_uart *hu)
>> +{
>> +	int ret;
>> +
>> +	ret = qca_send_vendor_cmd(hu->hdev, QCA_WCN3990_POWERON_PULSE);
>> +	if (ret)
>> +		return ret;
>> +
>> +	/* Wait for 100 ms for SoC to boot up */
>> +	msleep(100);
>> +	serdev_device_close(hu->serdev);
>> +	ret = serdev_device_open(hu->serdev);
>> +	if (ret) {
>> +		bt_dev_err(hu->hdev, "failed to open port");
>> +		return ret;
>> +	}
>> +
>> +	/* Setup initial baudrate */
>> +	qca_set_speed(hu, QCA_INIT_SPEED);
> 
> The comment is a bit redundant.
> 
>> +	hci_uart_set_flow_control(hu, false);
>> +
>> +	return 0;
>> +}
>> +
>>  static int qca_setup(struct hci_uart *hu)
>>  {
>>  	struct hci_dev *hdev = hu->hdev;
>>  	struct qca_data *qca = hu->priv;
>>  	unsigned int speed, qca_baudrate = QCA_BAUDRATE_115200;
>> +	struct qca_serdev *qcadev;
>>  	int ret;
>>  	int soc_ver = 0;
>> 
>> -	bt_dev_info(hdev, "ROME setup");
>> +	qcadev = serdev_device_get_drvdata(hu->serdev);
>> 
>>  	ret = qca_check_speeds(hu);
>>  	if (ret)
>> @@ -1006,6 +1137,21 @@ static int qca_setup(struct hci_uart *hu)
>>  	/* Setup initial baudrate */
>>  	qca_set_speed(hu, QCA_INIT_SPEED);
>> 
>> +	if (qcadev->btsoc_type == QCA_WCN3990) {
>> +		bt_dev_dbg(hdev, "setting up wcn3990");
> 
> Seems like this should be bt_dev_info() for consistency with Rome.
> 
>> +		ret = qca_wcn3990_init(hu);
>> +		if (ret)
>> +			return ret;
>> +
>> +		ret = qca_read_soc_version(hdev, &soc_ver);
>> +		if (ret < 0 || soc_ver == 0) {
>> +			bt_dev_err(hdev, "Failed to get version %d", ret);
>> +			return ret;
>> +		}
>> +	} else {
>> +		bt_dev_info(hdev, "ROME setup");
>> +	}
>> +
>>  	/* Setup user speed if needed */
>>  	speed = qca_get_speed(hu, QCA_OPER_SPEED);
>>  	if (speed) {
>> @@ -1016,16 +1162,18 @@ static int qca_setup(struct hci_uart *hu)
>>  		qca_baudrate = qca_get_baudrate_value(speed);
>>  	}
>> 
>> -	/* Get QCA version information */
>> -	ret = qca_read_soc_version(hdev, &soc_ver);
>> -	if (ret < 0 || soc_ver == 0) {
>> -		bt_dev_err(hdev, "QCA Failed to get version (%d)", ret);
>> -		return ret;
>> +	if (!soc_ver) {
> 
> 
> The following would probably be clearer:
> 
>   	if (qcadev->btsoc_type != QCA_WCN3990) {
> 
>> +		/* Get QCA version information */
>> +		ret = qca_read_soc_version(hdev, &soc_ver);
>> +		if (ret < 0 || soc_ver == 0) {
>> +			bt_dev_err(hdev, "QCA Failed to get version (%d)", ret);
>> +			return ret;
>> +		}
>> +		bt_dev_info(hdev, "QCA controller version 0x%08x", soc_ver);
> 
> Couldn't we hide some of this in qca_read_soc_version()?
> 
> qca_read_soc_version() could at least do the logging in the error case
> (the 'soc_ver == 0' case could be handled there as well), which would
> leave us with:
> 
> 
> 	ret = qca_read_soc_version(hdev, &soc_ver);
> 	if (ret)
> 		return ret;
> 
> And the same above.
> 
> The controller version can be logged outside of the branch for both
> wcn3990 and Rome.
> 
>>  	}
>> -	bt_dev_info(hdev, "QCA controller version 0x%08x", soc_ver);
>> 
>>  	/* Setup patch / NVM configurations */
>> -	ret = qca_uart_setup(hdev, qca_baudrate, QCA_ROME, soc_ver);
>> +	ret = qca_uart_setup(hdev, qca_baudrate, qcadev->btsoc_type, 
>> soc_ver);
>>  	if (!ret) {
>>  		set_bit(STATE_IN_BAND_SLEEP_ENABLED, &qca->flags);
>>  		qca_debugfs_init(hdev);
>> @@ -1061,9 +1209,123 @@ static struct hci_uart_proto qca_proto = {
>>  	.dequeue	= qca_dequeue,
>>  };
>> 
>> +static const struct qca_vreg_data qca_soc_data = {
>> +	.soc_type = QCA_WCN3990,
>> +	.vregs = (struct qca_vreg []) {
>> +		{ "vddio",   1800000, 1800000,  0 },
>> +		{ "vddxo",   1800000, 1800000,  1 },
>> +		{ "vddrf",   1304000, 1304000,  1 },
>> +		{ "vddch0",  3000000, 3312000,  1 },
>> +	},
>> +	.num_vregs = 4,
>> +};
> 
> I didn't chime in earlier in the discussion with Stephen on the
> regulators (https://patchwork.kernel.org/patch/10467911/), however I
> agree with him that specifying at load of 1uA doesn't seem to make
> much sense. What would happen if the load remained unspecified (or 0)?

[Bala]: On RPMh based designs, calling a regulator_set_load with a 
non-zero value moves the regulator to NPM (high power mode) which is 
required for BT communication.
         and call with 0uA  moves it to low-power-mode (vote from APPS). 
Basically whenever BT wants these in NPM  it calls set-load with 1.

-- 
Regards
Balakrishna.