can: mcp251xfd: Add support for internal loopback mode

MCP251xFD supports internal loopback mode which can be used to verify CAN
functionality in the absence of a real CAN device.

Link: https://lore.kernel.org/r/20201201054019.11012-1-manivannan.sadhasivam@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
[mkl: mcp251xfd_get_normal_mode(): move CAN_CTRLMODE_LOOPBACK check to front]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
index 20cbd5c..77129d5 100644 (file)
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
@@ -965,7 +965,10 @@ static u8 mcp251xfd_get_normal_mode(const struct mcp251xfd_priv *priv)
 {
        u8 mode;
 
-       if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
+
+       if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
+               mode = MCP251XFD_REG_CON_MODE_INT_LOOPBACK;
+       else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
                mode = MCP251XFD_REG_CON_MODE_LISTENONLY;
        else if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
                mode = MCP251XFD_REG_CON_MODE_MIXED;
@@ -2881,9 +2884,9 @@ static int mcp251xfd_probe(struct spi_device *spi)
        priv->can.do_get_berr_counter = mcp251xfd_get_berr_counter;
        priv->can.bittiming_const = &mcp251xfd_bittiming_const;
        priv->can.data_bittiming_const = &mcp251xfd_data_bittiming_const;
-       priv->can.ctrlmode_supported = CAN_CTRLMODE_LISTENONLY |
-               CAN_CTRLMODE_BERR_REPORTING | CAN_CTRLMODE_FD |
-               CAN_CTRLMODE_FD_NON_ISO;
+       priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
+               CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_BERR_REPORTING |
+               CAN_CTRLMODE_FD | CAN_CTRLMODE_FD_NON_ISO;
        priv->ndev = ndev;
        priv->spi = spi;
        priv->rx_int = rx_int;