From mboxrd@z Thu Jan 1 00:00:00 1970 From: "maxime.ripard@free-electrons.com" Date: Fri, 09 Jan 2015 22:31:38 +0000 Subject: Re: SSD1306 OLED driver Message-Id: <20150109223138.GB4891@lukather> MIME-Version: 1 Content-Type: multipart/mixed; boundary="WYTEVAkct0FjGQmd" List-Id: References: In-Reply-To: To: linux-fbdev@vger.kernel.org --WYTEVAkct0FjGQmd Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Jan 09, 2015 at 06:13:43PM +0530, Ssagarr Patil wrote: > Hi Maxime, >=20 > Thanks for your response! >=20 > > On Fri, Jan 09, 2015 at 03:45:01PM +0530, Ssagarr Patil wrote: > >> > >> Hi Maxime, > >> > >>>>> Thanks for the pointer, I am using spi_write() call and I see /dev/= fb0 node created. > >>>>> but when I do echo "1121"> /dev/fb0 nothing comes up on oled any po= inters on this ? > >>>> > >>>> You can't use it like that. It's a standard framebuffer, that is > >>>> represented as an array of pixels, so you need to use a font renderi= ng > >>>> software if you want to output some text. > >>>> > >>> can fbtest > >>> (https://git.kernel.org/cgit/linux/kernel/git/geert/fbtest.git/) > >>> be used to to draw something ? > >>> > >> how do I set pixels of it ? Please if you can point me to some stuff t= hat would be helpful. > > > > Last time I tried, fbtest didn't support monochrome display. > > > > And you'll find anything you need in the documentation. > > https://www.kernel.org/doc/Documentation/fb/framebuffer.txt > > > > In my case I see that init is done but I dont see any pixels on the > screen at all. > > I am now concerned if the driver was tested in first place ? No. I just submitted some good looking code that never ever got tested. More seriously, There's a few thing that comes to my mind: - Your controller doesn't behave the same way than the ones already supported. - You haven't posted your changes yet, so maybe you're not doing the transfers right - Your SPI controller is doing something weird What happens if you plug a logical analyzer on the bus? Maxime --=20 Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com --WYTEVAkct0FjGQmd Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJUsFbKAAoJEBx+YmzsjxAg9SgP/RTSWcoOvZOdJCR18ZSAEB3C ai+vsvXToLP9xCc63BgxJAOEIT+CJuQQDfOXCJdVX+pOO+IP1FcwNE29Dm7Rud63 775UoVJYz0DrNR5LlYwvIhkXb1oAB4nbvM3lvGBvUqr7iVsMNPHY0sFQgfi31GVL 40AzHJL4xCYDZAZw1uSR+v5iDbyUyih9W8jTF+bnrOex2Diif+q1di/J3JalNSwk s7kbxtJo7TkFkhMjYgX70XFr2uTnTJ+HmKe6KUswP06PmI0IW5Vye+48eI8GsJCv rH2h83hhM0qJmqBTQJuyIi7wWQThNHYGLj00pcOaRa05XVyjxV5MoE/vwRqtaX18 SMlc5FsY+/aasVz+JENRGBj9G1C0rATS2ynj0K5wsCVJwBeZk5V+CpahKBcX+5m1 jQdEib/t0sWCJiRk0HMaFrYYhCf5gVyu4tHWv/VhM073oUBthfF7Iqaf/iV3mHqH hHZdX+SHCb7xfdNFqb29zcI9Yr4bSdTdCmKR0wI6+zQqd1s72GcOCZ7UpM7g8VBR 5m7VRzK2jB7AOWfIIgxtIlEVPG0N3/H3aLUBMAcn6HsFLdtoDhUMs1ZjJx72Sw4C wN31szimEIIaQE06Z0sVKdcux8X9UUwkWbgEKUc3Odi3uI9opJ2WwXeWPnZfMm0q OZ8uovUBfKrGKMCeVgW4 =ImYc -----END PGP SIGNATURE----- --WYTEVAkct0FjGQmd--