On Mon, Oct 29, 2018 at 08:18:05PM +0530, Jagan Teki wrote: > On Mon, Oct 29, 2018 at 3:01 PM Maxime Ripard wrote: > > > > On Fri, Oct 26, 2018 at 08:13:35PM +0530, Jagan Teki wrote: > > > Some boards have VCC-DSI pin connected to voltage regulator which may > > > not be turned on by default. > > > > > > Add support for such boards by adding voltage regulator handling code to > > > MIPI DSI driver. > > > > > > Signed-off-by: Jagan Teki > > > Tested-by: Jagan Teki > > > --- > > > Changes for v3: > > > - new patch > > > Changes for v2: > > > - none > > > > > > drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 14 ++++++++++++++ > > > drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h | 3 +++ > > > 2 files changed, 17 insertions(+) > > > > > > diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > > > index 42bd7506abaf..bc57343592e0 100644 > > > --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > > > +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > > > @@ -949,6 +949,12 @@ static int sun6i_dsi_bind(struct device *dev, struct device *master, > > > > > > dsi->drv = drv; > > > > > > + ret = regulator_enable(dsi->regulator); > > > + if (ret) { > > > + dev_err(dev, "Failed to enable regulator\n"); > > > + return ret; > > > + } > > > + > > > > The regulator should be enabled only when the device is in use. > > True, but there is no device specific quirk needed because who ever > not needed simply use dummy regulator > [ 0.245821] sun6i-mipi-dsi 1ca0000.dsi: 1ca0000.dsi supply vcc-dsi > not found, using dummy regulato > r > > even like HVCC in hdmi driver [1] > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c?id=633ba1e086e1abbeef1ffd899911de8cf3987d9f That's not my point. You should enable the regulator only when the DSI bridge is being enabled, not when the driver has probed. Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com