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 <bgoda...@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.

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