Re: [PATCH v2 1/2] toshiba_acpi: Add support for WWAN devices

From: Darren Hart
Date: Fri Nov 20 2015 - 17:49:34 EST


On Thu, Nov 19, 2015 at 08:49:24AM -0700, Azael Avalos wrote:
> Toshiba laptops with WWAN devices installed cannot use the device unless
> it is attached and powered, similar to how Toshiba Bluetooth devices
> work.
>
> This patch adds support to WWAN devices, introducing three functions,
> one to query the overall status of the wireless devices (RFKill, WLAN,
> BT, WWAN), the second queries WWAN support, and finally the third
> (de)activates the device.
>
> Signed-off-by: Fabian Koester <fabian.koester@xxxxxxxxxxxx>
> Signed-off-by: Azael Avalos <coproscefalo@xxxxxxxxx>

Thanks Azael,

A few comments on code flow and one bug I think below.

> ---
> drivers/platform/x86/toshiba_acpi.c | 92 +++++++++++++++++++++++++++++++++++++
> 1 file changed, 92 insertions(+)
>
> diff --git a/drivers/platform/x86/toshiba_acpi.c b/drivers/platform/x86/toshiba_acpi.c
> index c013029..60d1ad9 100644
> --- a/drivers/platform/x86/toshiba_acpi.c
> +++ b/drivers/platform/x86/toshiba_acpi.c
> @@ -114,6 +114,7 @@ MODULE_LICENSE("GPL");
> #define HCI_VIDEO_OUT 0x001c
> #define HCI_HOTKEY_EVENT 0x001e
> #define HCI_LCD_BRIGHTNESS 0x002a
> +#define HCI_WIRELESS 0x0056
> #define HCI_ACCELEROMETER 0x006d
> #define HCI_KBD_ILLUMINATION 0x0095
> #define HCI_ECO_MODE 0x0097
> @@ -148,6 +149,10 @@ MODULE_LICENSE("GPL");
> #define SCI_KBD_MODE_ON 0x8
> #define SCI_KBD_MODE_OFF 0x10
> #define SCI_KBD_TIME_MAX 0x3c001a
> +#define HCI_WIRELESS_STATUS 0x1
> +#define HCI_WIRELESS_WWAN 0x3
> +#define HCI_WIRELESS_WWAN_STATUS 0x2000
> +#define HCI_WIRELESS_WWAN_POWER 0x4000
> #define SCI_USB_CHARGE_MODE_MASK 0xff
> #define SCI_USB_CHARGE_DISABLED 0x00
> #define SCI_USB_CHARGE_ALTERNATE 0x09
> @@ -197,12 +202,14 @@ struct toshiba_acpi_dev {
> unsigned int kbd_function_keys_supported:1;
> unsigned int panel_power_on_supported:1;
> unsigned int usb_three_supported:1;
> + unsigned int wwan_supported:1;
> unsigned int sysfs_created:1;
> unsigned int special_functions;
>
> bool kbd_led_registered;
> bool illumination_led_registered;
> bool eco_led_registered;
> + bool killswitch;
> };
>
> static struct toshiba_acpi_dev *toshiba_acpi;
> @@ -1085,6 +1092,87 @@ static int toshiba_hotkey_event_type_get(struct toshiba_acpi_dev *dev,
> return -EIO;
> }
>
> +/* Wireless status (RFKill, WLAN, BT, WWAN) */
> +static int toshiba_wireless_status(struct toshiba_acpi_dev *dev)
> +{
> + u32 in[TCI_WORDS] = { HCI_GET, HCI_WIRELESS, 0, 0, 0, 0 };
> + u32 out[TCI_WORDS];
> + acpi_status status;
> +
> + in[3] = HCI_WIRELESS_STATUS;
> + status = tci_raw(dev, in, out);
> + if (ACPI_FAILURE(status)) {
> + pr_err("ACPI call to get Wireless status failed\n");
> + } else if (out[0] == TOS_NOT_SUPPORTED) {
> + return -ENODEV;
> + } else if (out[0] == TOS_SUCCESS) {
> + dev->killswitch =
> + (out[2] & HCI_WIRELESS_STATUS) ? true : false;

This should assign successfully without the need for the ternary operator. You
can also then drop the extra newline. You can always use:

!!(out[2] & HCI_WIRELESS_STATUS)

To ensure a 1 or 0 assignment.

> + return 0;
> + }
> +
> + return -EIO;

Also, we should be testing for error and do the expected path outside the if
blocks.


if (ACPI_FAILURE(status) {
pr_err("ACPI call to get Wireless status failed\n");
return -EIO;
}

if (out[0] == TOS_NOT_SUPPORTED)
return -ENODEV;

if (out[0] != TOS_SUCCESS)
return -EIO;

dev->killswitch = !!(out[2] & HCI_WIRELESS_STATUS);

return 0;

> +}
> +
> +/* WWAN */
> +static void toshiba_wwan_available(struct toshiba_acpi_dev *dev)
> +{
> + u32 in[TCI_WORDS] = { HCI_GET, HCI_WIRELESS, 0, 0, 0, 0 };
> + u32 out[TCI_WORDS];
> + acpi_status status;
> +
> + dev->wwan_supported = 0;
> +
> + /*
> + * WWAN support can be queried by setting the in[3] value to
> + * HCI_WIRELESS_WWAN (0x03).
> + *
> + * If supported, out[0] contains TOS_SUCCESS and out[2] contains
> + * HCI_WIRELESS_WWAN_STATUS (0x2000).
> + *
> + * If not supported, out[0] contains TOS_INPUT_DATA_ERROR (0x8300)
> + * or TOS_NOT_SUPPORTED (0x8000).
> + */
> + in[3] = HCI_WIRELESS_WWAN;
> + status = tci_raw(dev, in, out);
> + if (ACPI_FAILURE(status))
> + pr_err("ACPI call to get WWAN status failed\n");
> + else if (out[0] == TOS_SUCCESS && out[2] == HCI_WIRELESS_WWAN_STATUS)
> + dev->wwan_supported = 1;

This block similarly intermixes error checking with the primary functional
logic, making it less legible in my opinion. Consider:


in[3] = HCI_WIRELESS_WWAN;
status = tci_raw(dev, in, out);

if (ACPI_FAILURE(status) || (out[0] != TOS_SUCCESS)) {
pr_err("ACPI call to get WWAN status failed\n");
return;
}

dev->wwan_supported = (out[2] == HCI_WIRELESS_WWAN_STATUS);

> +}
> +
> +static int toshiba_wwan_set(struct toshiba_acpi_dev *dev, u32 state)
> +{
> + u32 in[TCI_WORDS] = { HCI_SET, HCI_WIRELESS, state, 0, 0, 0 };
> + u32 out[TCI_WORDS];
> + acpi_status status;
> +
> + in[3] = HCI_WIRELESS_WWAN_STATUS;
> + status = tci_raw(dev, in, out);
> + if (ACPI_FAILURE(status)) {
> + pr_err("ACPI call to set WWAN status failed\n");
> + return -EIO;
> + } else if (out[0] == TOS_NOT_SUPPORTED) {
> + return -ENODEV;
> + } else if (out[0] != TOS_SUCCESS) {
> + return -EIO;
> + }
> +
> + /*
> + * Some devices only need to call HCI_WIRELESS_WWAN_STATUS to
> + * (de)activate the device, but some others need the
> + * HCI_WIRELESS_WWAN_POWER call as well.
> + */
> + in[3] = HCI_WIRELESS_WWAN_POWER;
> + status = tci_raw(dev, in, out);
> + if (ACPI_FAILURE(status))
> + pr_err("ACPI call to set WWAN power failed\n");

I believe you want a return -EIO here?

> + else if (out[0] == TOS_NOT_SUPPORTED)
> + return -ENODEV;
> +
> + return out[0] == TOS_SUCCESS ? 0 : -EIO;

So much ternary! :-) I suppose this one is OK.

> +}
> +
> /* Transflective Backlight */
> static int get_tr_backlight_status(struct toshiba_acpi_dev *dev, u32 *status)
> {
> @@ -2561,6 +2649,8 @@ static void print_supported_features(struct toshiba_acpi_dev *dev)
> pr_cont(" panel-power-on");
> if (dev->usb_three_supported)
> pr_cont(" usb3");
> + if (dev->wwan_supported)
> + pr_cont(" wwan");
>
> pr_cont("\n");
> }
> @@ -2736,6 +2826,8 @@ static int toshiba_acpi_add(struct acpi_device *acpi_dev)
> ret = get_fan_status(dev, &dummy);
> dev->fan_supported = !ret;
>
> + toshiba_wwan_available(dev);
> +
> print_supported_features(dev);
>
> ret = sysfs_create_group(&dev->acpi_dev->dev.kobj,
> --
> 2.6.2
>
>

--
Darren Hart
Intel Open Source Technology Center
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