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

From: Matthias Kaehlcke
Date: Fri Jul 06 2018 - 18:21:19 EST

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In reply to: Balakrishna Godavarthi: "[PATCH v9 7/7] Bluetooth: hci_qca: Add support for Qualcomm Bluetooth chip wcn3990"
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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@xxxxxxxxxxxxxx>
> ---
> 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)?

Next message: Al Viro: "Re: [PATCH v6 0/7] fs/dcache: Track & limit # of negative dentries"
Previous message: Willem de Bruijn: "Re: KASAN: use-after-free Read in ipv6_gso_pull_exthdrs"
In reply to: Balakrishna Godavarthi: "[PATCH v9 7/7] Bluetooth: hci_qca: Add support for Qualcomm Bluetooth chip wcn3990"
Next in thread: Balakrishna Godavarthi: "[PATCH v9 5/7] Bluetooth: hci_qca: Enable 3.2 Mbps operating speed."
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