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path: root/drivers/gpu/drm/sun4i/sun4i_dotclock.c
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2016-09-20drm/sun4i: dotclock: Round to closest clock rateChen-Yu Tsai
With display pixel clocks we want to have the closest possible clock rate, to minimize timing and refresh rate skews. Whether the actual clock rate is higher or lower than the requested rate is less important. Also check candidates against the requested rate, rather than the ideal parent rate, the varying dividers also influence the difference between the requested rate and the rounded rate. Signed-off-by: Chen-Yu Tsai <wens@csie.org> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
2016-09-18drm/sun4i: dotclock: Allow divider = 127Chen-Yu Tsai
The dot clock divider is 7 bits wide, and the divider range is 1 ~ 127, or 6 ~ 127 if phase offsets are used. The 0 register value also represents a divider of 1 or bypass. Make the end condition of the for loop inclusive of 127 in the round_rate callback. Signed-off-by: Chen-Yu Tsai <wens@csie.org> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
2016-09-18drm/sun4i: dotclock: Fix clock rate read back calcationChen-Yu Tsai
When reading back the divider set in the register, we mask off the bits that aren't part of the divider. Unfortunately the mask used here was not converted from the field width. Fix this by converting the field width to a proper bit mask. Fixes: 9026e0d122ac ("drm: Add Allwinner A10 Display Engine support") Signed-off-by: Chen-Yu Tsai <wens@csie.org> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
2016-09-08drm/sun4i: add missing header dependenciesBaoyou Xie
We get 5 warnings when building kernel with W=1: drivers/gpu/drm/sun4i/sun4i_framebuffer.c:33:23: warning: no previous prototype for 'sun4i_framebuffer_init' [-Wmissing-prototypes] drivers/gpu/drm/sun4i/sun4i_framebuffer.c:47:6: warning: no previous prototype for 'sun4i_framebuffer_free' [-Wmissing-prototypes] drivers/gpu/drm/sun4i/sun4i_rgb.c:202:5: warning: no previous prototype for 'sun4i_rgb_init' [-Wmissing-prototypes] drivers/gpu/drm/sun4i/sun4i_dotclock.c:151:5: warning: no previous prototype for 'sun4i_dclk_create' [-Wmissing-prototypes] drivers/gpu/drm/sun4i/sun4i_dotclock.c:186:5: warning: no previous prototype for 'sun4i_dclk_free' [-Wmissing-prototypes] In fact, these functions are declared in drivers/gpu/drm/sun4i/sun4i_framebuffer.h, drivers/gpu/drm/sun4i/sun4i_rgb.h, drivers/gpu/drm/sun4i/sun4i_dotclock.h, so this patch adds missing header dependencies. Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
2016-05-30drm/sun4i: request exact rates to our parentsMaxime Ripard
Our pixel clock currently only tries to deal with the current parent rate. While that works when the resolution is the same than the one already program, or when we can compute directly the rate from the current parent rate, it cannot work in most situation when we want to change the frequency, and we end up with an improper pixel clock rate, which obviously doesn't work as expected. Ask our parent for all the possible dividers if it can reach that frequency, and return the best parent rate to the clock framework so that we can use it. Fixes: 9026e0d122ac ("drm: Add Allwinner A10 Display Engine support") Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
2016-05-30drm: sun4i: fix probe error handlingArnd Bergmann
gcc points out a possible uninitialized variable use in sun4i_dclk_create(): drivers/gpu/drm/sun4i/sun4i_dotclock.c: In function 'sun4i_dclk_create': drivers/gpu/drm/sun4i/sun4i_dotclock.c:139:12: error: 'clk_name' may be used uninitialized in this function [-Werror=maybe-uninitialized] init.name = clk_name; The warning only shows up when CONFIG_OF is disabled, and the property is never filled, but the same bug can show up even when CONFIG_OF is enabled but of_property_read_string_index returns another error. To fix it, this ensures that sun4i_dclk_create propagates any error from of_property_read_string_index. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 9026e0d122ac ("drm: Add Allwinner A10 Display Engine support") Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
2016-04-28drm: Add Allwinner A10 Display Engine supportMaxime Ripard
The Allwinner A10 and subsequent SoCs share the same display pipeline, with variations in the number of controllers (1 or 2), or the presence or not of some output (HDMI, TV, VGA) or not. Add a driver with a limited set of features for now, and we will hopefully support all of them eventually Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>