From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomi Valkeinen Date: Thu, 19 Jan 2017 15:08:27 +0000 Subject: Re: [PATCH v2 4/5] fbdev/ssd1307fb: add support to enable VBAT Message-Id: MIME-Version: 1 Content-Type: multipart/mixed; boundary="T9IJq4abRnjGMjb3b3HrXaIoUQ6xFiapH" List-Id: References: <214ae9ca86009148f233be71a3606917f3150dcd.1484303628.git.jsarha@ti.com> <20170118223310.kxbgq47v7cl33ls3@rob-hp-laptop> <754f3644-a157-bb90-1494-aba4fc1264f8@ti.com> In-Reply-To: To: Rob Herring Cc: Jyri Sarha , "linux-fbdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Bartlomiej Zolnierkiewicz , Maxime Ripard , Benoit Cousson --T9IJq4abRnjGMjb3b3HrXaIoUQ6xFiapH Content-Type: multipart/mixed; boundary="empFKEKU7rT8g3iVWOQK2EbjOP3F9PMFn"; protected-headers="v1" From: Tomi Valkeinen To: Rob Herring Cc: Jyri Sarha , "linux-fbdev@vger.kernel.org" , "devicetree@vger.kernel.org" , Bartlomiej Zolnierkiewicz , Maxime Ripard , Benoit Cousson Message-ID: Subject: Re: [PATCH v2 4/5] fbdev/ssd1307fb: add support to enable VBAT References: <214ae9ca86009148f233be71a3606917f3150dcd.1484303628.git.jsarha@ti.com> <20170118223310.kxbgq47v7cl33ls3@rob-hp-laptop> <754f3644-a157-bb90-1494-aba4fc1264f8@ti.com> In-Reply-To: --empFKEKU7rT8g3iVWOQK2EbjOP3F9PMFn Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 19/01/17 17:03, Rob Herring wrote: >>> According to the datasheet, SSD1307 has 2 supplies: Vdd and Vcc >>> >>> I don't see any mention of a charge pump, so that must be an external= >>> component. >> >> VBAT is for SSD1306. Perhaps the DT doc should mention it. >=20 > Datasheet says VBAT is reserved, connect to Vdd. I would just describe > Vdd and Vcc in that case. I'm no HW guy, but as far as I understand, you can wire it up two ways. One has VBAT connected to VDD. The other one has VBAT connected to external supply. See "Figure 1 : Application Example of SSD1306Z with charge bump". Tomi --empFKEKU7rT8g3iVWOQK2EbjOP3F9PMFn-- --T9IJq4abRnjGMjb3b3HrXaIoUQ6xFiapH Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJYgNZrAAoJEPo9qoy8lh71oqIP/2n12MJoZ7Q66EiK4FHpYAQU OWs8GH09IqCklw6LoCp1e2GJGr7rGTIwSzJ+771VOlnXPZiGsVAKhoSzrXnFXJLW XArFG5qz4RiUVVcW24D8t7qByH7hrJHfbUubQbGRcCKpaq78Er7q9+4Q9DRIOvCB 9YjZJJfiKCFscf47kXkrosjtAnRJzPgO1AKXjphr5Xg2lZ/CmaDgb1zdBDPD6Aq5 8eB6+YXbg3F+4WWJi3Wwyf6UjlOi8y6wzns+327fbbPBaJHYQmqxONgSCV7df1PL Ezqf2NqL39HUhM2nZFhdLJQu2Co4ZGSQd/fFVUGGE0tlGPfw0hG+TYZbnKbB3S8R 5/5r/lfEeS9NoehtEYgLvyUrIP8Ov7ucotpTbZmIN5Cc1OJWXD3bJpFBAHAxYd9R 4eD61X2i5wgiTJ+QFh69xqyVqQ+KZNVjIhGUa9QP7LQ1fyHtn8vy9In3lKCWxWBk U6fqgtK2dEF3LKGJmUuGTg99aFd0PmIcjWcUCWpeTkbHD0/RgNsHD+W1n5spvXw5 GpCbojcQiM2A2XvGva6f1aY+/EFu3OPrSeHNWyxzsOR/TOAyXwRVG6zLAJ4uzNlk CN+aYATwOyuIyhCSQwrNC/5v+H8gzrihHFCkbKz4woN3bDu27K8+CsZJWhaW1JLS 0WFVIG+65bcpxEPTjZ0+ =5Ef5 -----END PGP SIGNATURE----- --T9IJq4abRnjGMjb3b3HrXaIoUQ6xFiapH--