Re: [PATCH v4 3/3] Bluetooth: hci_qca: Add serdev support

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Wed, 2018-03-14 at 16:55 +0100, Thierry Escande wrote:
> Add support for Qualcomm serial slave devices. Probe the serial
> device,
> retrieve its maximum speed and register a new hci uart device.
> 

FWIW,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> Signed-off-by: Thierry Escande <thierry.escande@linaro.org>
> ---
> 
> v4:
> - Rename divclk4 as susclk (its name in the bt chip)
> - Use gpiod_set_value_cansleep()
> - Replace #include <linux/of.h> with <linux/mod_devicetable.h>
> - Restore dependency on BT_HCIUART
> 
> v3:
> - Remove redundant call to gpiod_set_value() after devm_gpiod_get()
> - Check returned values for clk_set_rate() and clk_prepare_enable()
> - Use clk_disable_unprepare()
> 
> v2:
> - Fix author email
> 
>  drivers/bluetooth/Kconfig   |   1 +
>  drivers/bluetooth/hci_qca.c | 109
> +++++++++++++++++++++++++++++++++++++++++++-
>  2 files changed, 108 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig
> index 07e55cd8f8c8..e0f1a6609b68 100644
> --- a/drivers/bluetooth/Kconfig
> +++ b/drivers/bluetooth/Kconfig
> @@ -196,6 +196,7 @@ config BT_HCIUART_BCM
>  config BT_HCIUART_QCA
>  	bool "Qualcomm Atheros protocol support"
>  	depends on BT_HCIUART
> +	depends on BT_HCIUART_SERDEV
>  	select BT_HCIUART_H4
>  	select BT_QCA
>  	help
> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
> index 05ec530b8a3a..6cf0d1d4595a 100644
> --- a/drivers/bluetooth/hci_qca.c
> +++ b/drivers/bluetooth/hci_qca.c
> @@ -29,7 +29,11 @@
>   */
>  
>  #include <linux/kernel.h>
> +#include <linux/clk.h>
>  #include <linux/debugfs.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/serdev.h>
>  
>  #include <net/bluetooth/bluetooth.h>
>  #include <net/bluetooth/hci_core.h>
> @@ -50,6 +54,9 @@
>  #define IBS_TX_IDLE_TIMEOUT_MS		2000
>  #define BAUDRATE_SETTLE_TIMEOUT_MS	300
>  
> +/* susclk rate */
> +#define SUSCLK_RATE_32KHZ	32768
> +
>  /* HCI_IBS transmit side sleep protocol states */
>  enum tx_ibs_states {
>  	HCI_IBS_TX_ASLEEP,
> @@ -111,6 +118,12 @@ struct qca_data {
>  	u64 votes_off;
>  };
>  
> +struct qca_serdev {
> +	struct hci_uart	 serdev_hu;
> +	struct gpio_desc *bt_en;
> +	struct clk	 *susclk;
> +};
> +
>  static void __serial_clock_on(struct tty_struct *tty)
>  {
>  	/* TODO: Some chipset requires to enable UART clock on client
> @@ -386,6 +399,7 @@ static void hci_ibs_wake_retrans_timeout(struct
> timer_list *t)
>  /* Initialize protocol */
>  static int qca_open(struct hci_uart *hu)
>  {
> +	struct qca_serdev *qcadev;
>  	struct qca_data *qca;
>  
>  	BT_DBG("hu %p qca_open", hu);
> @@ -444,6 +458,13 @@ static int qca_open(struct hci_uart *hu)
>  	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);
> +	}
> +
>  	BT_DBG("HCI_UART_QCA open, tx_idle_delay=%u,
> wake_retrans=%u",
>  	       qca->tx_idle_delay, qca->wake_retrans);
>  
> @@ -512,6 +533,7 @@ static int qca_flush(struct hci_uart *hu)
>  /* Close protocol */
>  static int qca_close(struct hci_uart *hu)
>  {
> +	struct qca_serdev *qcadev;
>  	struct qca_data *qca = hu->priv;
>  
>  	BT_DBG("hu %p qca close", hu);
> @@ -525,6 +547,13 @@ static int qca_close(struct hci_uart *hu)
>  	destroy_workqueue(qca->workqueue);
>  	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);
> +	}
> +
>  	kfree_skb(qca->rx_skb);
>  
>  	hu->priv = NULL;
> @@ -885,6 +914,14 @@ static int qca_set_baudrate(struct hci_dev *hdev,
> uint8_t baudrate)
>  	return 0;
>  }
>  
> +static inline void host_set_baudrate(struct hci_uart *hu, unsigned
> int speed)
> +{
> +	if (hu->serdev)
> +		serdev_device_set_baudrate(hu->serdev, speed);
> +	else
> +		hci_uart_set_baudrate(hu, speed);
> +}
> +
>  static int qca_setup(struct hci_uart *hu)
>  {
>  	struct hci_dev *hdev = hu->hdev;
> @@ -905,7 +942,7 @@ static int qca_setup(struct hci_uart *hu)
>  		speed = hu->proto->init_speed;
>  
>  	if (speed)
> -		hci_uart_set_baudrate(hu, speed);
> +		host_set_baudrate(hu, speed);
>  
>  	/* Setup user speed if needed */
>  	speed = 0;
> @@ -924,7 +961,7 @@ static int qca_setup(struct hci_uart *hu)
>  				   ret);
>  			return ret;
>  		}
> -		hci_uart_set_baudrate(hu, speed);
> +		host_set_baudrate(hu, speed);
>  	}
>  
>  	/* Setup patch / NVM configurations */
> @@ -958,12 +995,80 @@ static struct hci_uart_proto qca_proto = {
>  	.dequeue	= qca_dequeue,
>  };
>  
> +static int qca_serdev_probe(struct serdev_device *serdev)
> +{
> +	struct qca_serdev *qcadev;
> +	int err;
> +
> +	qcadev = devm_kzalloc(&serdev->dev, sizeof(*qcadev),
> GFP_KERNEL);
> +	if (!qcadev)
> +		return -ENOMEM;
> +
> +	qcadev->serdev_hu.serdev = serdev;
> +	serdev_device_set_drvdata(serdev, qcadev);
> +
> +	qcadev->bt_en = devm_gpiod_get(&serdev->dev, "bt-disable-n",
> +				       GPIOD_OUT_LOW);
> +	if (IS_ERR(qcadev->bt_en)) {
> +		dev_err(&serdev->dev, "failed to acquire bt-disable-n 
> gpio\n");
> +		return PTR_ERR(qcadev->bt_en);
> +	}
> +
> +	qcadev->susclk = devm_clk_get(&serdev->dev, NULL);
> +	if (IS_ERR(qcadev->susclk)) {
> +		dev_err(&serdev->dev, "failed to acquire clk\n");
> +		return PTR_ERR(qcadev->susclk);
> +	}
> +
> +	err = clk_set_rate(qcadev->susclk, SUSCLK_RATE_32KHZ);
> +	if (err)
> +		return err;
> +
> +	err = clk_prepare_enable(qcadev->susclk);
> +	if (err)
> +		return err;
> +
> +	err = hci_uart_register_device(&qcadev->serdev_hu,
> &qca_proto);
> +	if (err)
> +		clk_disable_unprepare(qcadev->susclk);
> +
> +	return err;
> +}
> +
> +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);
> +}
> +
> +static const struct of_device_id qca_bluetooth_of_match[] = {
> +	{ .compatible = "qcom,qca6174-bt" },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, qca_bluetooth_of_match);
> +
> +static struct serdev_device_driver qca_serdev_driver = {
> +	.probe = qca_serdev_probe,
> +	.remove = qca_serdev_remove,
> +	.driver = {
> +		.name = "hci_uart_qca",
> +		.of_match_table = qca_bluetooth_of_match,
> +	},
> +};
> +
>  int __init qca_init(void)
>  {
> +	serdev_device_driver_register(&qca_serdev_driver);
> +
>  	return hci_uart_register_proto(&qca_proto);
>  }
>  
>  int __exit qca_deinit(void)
>  {
> +	serdev_device_driver_unregister(&qca_serdev_driver);
> +
>  	return hci_uart_unregister_proto(&qca_proto);
>  }

-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy