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authorMark Cave-Ayland <mark.cave-ayland@ilande.co.uk>2020-10-27 15:04:55 +0000
committerGerd Hoffmann <kraxel@redhat.com>2020-11-04 07:22:37 +0100
commita79f86cdbe9ccd5c3be76a9c6288d07a7716cb12 (patch)
treeb41a495fd92c98794d31772a2e9ba248fcda59b3 /hw/usb/dev-serial.c
parent66007a95674d4b8e616245541faad6cdf5e9f70d (diff)
downloadfocaccia-qemu-a79f86cdbe9ccd5c3be76a9c6288d07a7716cb12.tar.gz
focaccia-qemu-a79f86cdbe9ccd5c3be76a9c6288d07a7716cb12.zip
dev-serial: add support for setting data_bits in QEMUSerialSetParams
Also implement the behaviour reported in Linux's ftdi_sio.c whereby if an invalid
data_bits value is provided then the hardware defaults to using 8.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20201027150456.24606-8-mark.cave-ayland@ilande.co.uk
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Diffstat (limited to 'hw/usb/dev-serial.c')
-rw-r--r--hw/usb/dev-serial.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/hw/usb/dev-serial.c b/hw/usb/dev-serial.c
index b9e308dca1..e42ce36295 100644
--- a/hw/usb/dev-serial.c
+++ b/hw/usb/dev-serial.c
@@ -308,6 +308,23 @@ static void usb_serial_handle_control(USBDevice *dev, USBPacket *p,
         break;
     }
     case VendorDeviceOutRequest | FTDI_SET_DATA:
+        switch (value & 0xff) {
+        case 7:
+            s->params.data_bits = 7;
+            break;
+        case 8:
+            s->params.data_bits = 8;
+            break;
+        default:
+            /*
+             * According to a comment in Linux's ftdi_sio.c original FTDI
+             * chips fall back to 8 data bits for unsupported data_bits
+             */
+            trace_usb_serial_unsupported_data_bits(bus->busnr, dev->addr,
+                                                   value & 0xff);
+            s->params.data_bits = 8;
+        }
+
         switch (value & FTDI_PARITY) {
         case 0:
             s->params.parity = 'N';