From d47fa5315cca0c7c06b97abfbd77859d5296be2c Mon Sep 17 00:00:00 2001 From: Antti Palosaari Date: Fri, 23 Oct 2015 20:01:31 -0200 Subject: [PATCH] [media] hackrf: move RF gain ctrl enable behind module parameter Used Avago MGA-81563 RF amplifier could be destroyed pretty easily with too strong signal or transmitting to bad antenna. Add module parameter 'enable_rf_gain_ctrl' which allows enabling RF gain control - otherwise, default without the module parameter, RF gain control is set to 'grabbed' state which prevents setting value to the control. Signed-off-by: Antti Palosaari Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/hackrf/hackrf.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/media/usb/hackrf/hackrf.c b/drivers/media/usb/hackrf/hackrf.c index 84e8a4210e2e..0fe5cb2c260c 100644 --- a/drivers/media/usb/hackrf/hackrf.c +++ b/drivers/media/usb/hackrf/hackrf.c @@ -24,6 +24,15 @@ #include #include +/* + * Used Avago MGA-81563 RF amplifier could be destroyed pretty easily with too + * strong signal or transmitting to bad antenna. + * Set RF gain control to 'grabbed' state by default for sure. + */ +static bool hackrf_enable_rf_gain_ctrl; +module_param_named(enable_rf_gain_ctrl, hackrf_enable_rf_gain_ctrl, bool, 0644); +MODULE_PARM_DESC(enable_rf_gain_ctrl, "enable RX/TX RF amplifier control (warn: could damage amplifier)"); + /* HackRF USB API commands (from HackRF Library) */ enum { CMD_SET_TRANSCEIVER_MODE = 0x01, @@ -1451,6 +1460,7 @@ static int hackrf_probe(struct usb_interface *intf, dev_err(dev->dev, "Could not initialize controls\n"); goto err_v4l2_ctrl_handler_free_rx; } + v4l2_ctrl_grab(dev->rx_rf_gain, !hackrf_enable_rf_gain_ctrl); v4l2_ctrl_handler_setup(&dev->rx_ctrl_handler); /* Register controls for transmitter */ @@ -1471,6 +1481,7 @@ static int hackrf_probe(struct usb_interface *intf, dev_err(dev->dev, "Could not initialize controls\n"); goto err_v4l2_ctrl_handler_free_tx; } + v4l2_ctrl_grab(dev->tx_rf_gain, !hackrf_enable_rf_gain_ctrl); v4l2_ctrl_handler_setup(&dev->tx_ctrl_handler); /* Register the v4l2_device structure */