Hi Mathieu, > > Hi everybody, > > > > I was wondering if anyone had implemented hardware flow control support > > in the cpm_uart driver. If not, I would appreciate pointers regarding how > > to do so. > > > > Best regards, > > > > Laurent Pinchart > > I had. PQ2 CPM is a dedicated part which handles this aspect for you via > its microcode. This also means you can't play with it the old way and > making your own HHS with a CD/DSR :). Back to seriousness, rather this > means you needn't adding modem signal handling in cpm_uart driver. So don't > define modem_something that's an ancient reliq from the times, I guess, no > CPM was put auxillary. > > So how to tell CPM to cope with HHS ? Simple, you "just" have to put SCC's > Dedicated pins the right way which depends on your board type. Remember you > can't do any HHS with SMC. Refer to Dedicated Pins chapter in the > litterature [41.4.2]. Also take a look at SCC GSMR register [20.8] and to > SCC UART mode PSMR register [21-14] to maybe use protocol specificities.
Thanks. > When you'll have your kernel ready, you would do probably something like : > stty -F $port crtscts $SPEED I suppose I also have to add support for the CRTSCTS flag in set_termios. > As Wolfgang said HHS works for DTE-DCE only (roughly but visually you must > have plugs opposite gender on both ends), trying DTE-DTE HHS dialog is > bound to failure despite time spend on it. I'll disable hardware flow control if I need DTE-DTE communication. Thanks for your help. Laurent Pinchart
