Re: [PATCH v13 7/7] Bluetooth: hci_qca: Add support for Qualcomm Bluetooth chip wcn3990

From: Balakrishna Godavarthi
Date: Thu Aug 02 2018 - 16:10:58 EST


On 2018-08-03 01:27, Matthias Kaehlcke wrote:
On Fri, Aug 03, 2018 at 12:37:32AM +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>
Reviewed-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
---
Changes in v13:
* updated review comments.

Changes in v12:
* removed retrying iteration loop in qca_wcn3990_init.

Changes in v11:
* removed support to read regulator currents from dts.
* updated review comments.

Changes in v10:
* added support to read regulator currents from dts.
* added support to try to connect with chip if it fails to respond to initial commands
* updated review comments.

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 | 402 +++++++++++++++++++++++++++++++-----
2 files changed, 358 insertions(+), 47 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 a6e7d38ef931..66f36527e4dd 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_dev *hdev);
+
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->hdev);
+ 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 mandatory while
+ * 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 +997,43 @@ static inline void host_set_baudrate(struct hci_uart *hu, unsigned int speed)
hci_uart_set_baudrate(hu, speed);
}

+static int qca_send_power_pulse(struct hci_dev *hdev, u8 cmd)
+{
+ struct hci_uart *hu = hci_get_drvdata(hdev);
+ struct qca_data *qca = hu->priv;
+ struct sk_buff *skb;
+
+ /* These power pulses are single byte command which are sent
+ * at required baudrate to wcn3990. On wcn3990, we have an external
+ * circuit at Tx pin which decodes the pulse sent at specific baudrate.
+ * For example, wcn3990 supports RF COEX antenna for both Wi-Fi/BT
+ * and also we use the same power inputs to turn on and off for
+ * Wi-Fi/BT. Powering up the power sources will not enable BT, until
+ * we send a power on pulse at 115200 bps. This algorithm will help to
+ * save power. Disabling hardware flow control is mandatory while
+ * sending power pulses to SoC.
+ */
+ bt_dev_dbg(hdev, "sending power pulse %02x to SoC", cmd);
+
+ skb = bt_skb_alloc(sizeof(cmd), GFP_KERNEL);
+ if (!skb)
+ return -ENOMEM;
+
+ hci_uart_set_flow_control(hu, true);
+
+ 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);
+ 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)
{
@@ -952,9 +1056,18 @@ static unsigned int qca_get_speed(struct hci_uart *hu,

static int qca_check_speeds(struct hci_uart *hu)
{
- if (!qca_get_speed(hu, QCA_INIT_SPEED) ||
- !qca_get_speed(hu, QCA_OPER_SPEED))
- return -EINVAL;
+ struct qca_serdev *qcadev;
+
+ qcadev = serdev_device_get_drvdata(hu->serdev);
+ 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;
}
@@ -974,7 +1087,7 @@ static int qca_set_speed(struct hci_uart *hu, enum qca_speed_type speed_type)
return 0;

qca_baudrate = qca_get_baudrate_value(speed);
- bt_dev_info(hu->hdev, "Set UART speed to %d", speed);
+ bt_dev_dbg(hu->hdev, "Set UART speed to %d", speed);
ret = qca_set_baudrate(hu->hdev, qca_baudrate);
if (ret)
return ret;
@@ -985,15 +1098,51 @@ 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, u32 *soc_ver)
+{

I focussed more on other things in the last review rounds and
overlooked that qca_read_soc_version() and the soc_ver pointer slipped
in here with v10 (v9: https://patchwork.kernel.org/patch/10510029/).

In a similar line as in an earlier discussion about reading the SoC
version in qca_uart_setup() (https://patchwork.kernel.org/patch/10467903/)
I don't think the init function is the right place and it shouldn't
receive this soc_ver parameter about which it doesn't really
care. Please switch back as it was in v9 and read the SoC version in
qca_setup() (like it is done for Rome).

Then we should be done from my side.

so it should be some thing like this?

if (qcadev->btsoc_type == QCA_WCN3990) {
bt_dev_info(hdev, "setting up wcn3990");
ret = qca_wcn3990_init(hu);
if (ret)
return ret;
hci_uart_set_flow_control(hu, false);
ret = qca_read_soc_version(hdev, &soc_ver);
if (ret)
return ret;
}

--
Regards
Balakrishna.