Hi Rob,
On Wed, Jan 23, 2013 at 04:06:22, Rob Clark wrote:
> A simple DRM/KMS driver for the TI LCD Controller found in various
> smaller TI parts (AM33xx, OMAPL138, etc). This driver uses the
> +void tilcdc_crtc_update_clk(struct drm_crtc *crtc)
> + /* in raster mode, minimum divisor is 2: */
> + ret = clk_set_rate(priv->disp_clk, crtc->mode.clock * 1000 * 2);
These things can better be handled with divider clock having a
minimum value (being discussed with Mike on how exactly it should
be) and instead of setting rate over a platform specific clock,
you can set rate over lcd clock using SET_RATE_PARENT at platform
level, more below,
> + /* Configure the LCD clock divisor. */
> + tilcdc_write(dev, LCDC_CTRL_REG, LCDC_CLK_DIVISOR(div) |
> + LCDC_RASTER_MODE);
> +
> + if (priv->rev == 2)
> + tilcdc_set(dev, LCDC_CLK_ENABLE_REG,
> + LCDC_V2_DMA_CLK_EN | LCDC_V2_LIDD_CLK_EN |
> + LCDC_V2_CORE_CLK_EN);
Mike was suggesting to model the above using gate/divider/composite
clocks of CCF in the FB driver.
> + priv->clk = clk_get(dev->dev, "fck");
> + if (IS_ERR(priv->clk)) {
> + dev_err(dev->dev, "failed to get functional clock\n");
> + ret = -ENODEV;
> + goto fail;
> + }
> +
> + priv->disp_clk = clk_get(dev->dev, "dpll_disp_ck");
> + if (IS_ERR(priv->clk)) {
> + dev_err(dev->dev, "failed to get display clock\n");
> + ret = -ENODEV;
> + goto fail;
> + }
"dpll_disp_ck" is a platform specific matter, driver should not
be handling platform specifics. And this won't work on DaVinci,
you can probably make use of
my series "[PATCH v2 0/4] ARM: AM335x: LCDC platform support"
or something similar to overcome this.
Regards
Afzal
