The XLCDC IP supports parallel RGB, MIPI DSI and LVDS Display. The LCD Generic clock (sys_clk) is used for Parallel RGB and MIPI displays, while the LVDS PLL clock (lvds_pll_clk) is used for LVDS displays.Since both the clocks cannot co-exist together in the DT for a given display, this patch tries sys_clk first (RGB/MIPI), fallback to lvds_pll_clk (LVDS).
Signed-off-by: Manikandan Muralidharan <[email protected]> Signed-off-by: Dharma Balasubiramani <[email protected]> --- changes in v3: - Rephrase the comments, err logs. - assign NULL to sys_clk to avoid Oops error when referenced in pwm-atmel-hlcdc.c changes in v2: - Rephrase the comments, commit message and err logs - Replace dev_err wwith dev_warn - Remove Initializing sys_clk and lvds_pll_clk to NULL post devm_kzalloc() call --- drivers/mfd/atmel-hlcdc.c | 13 +++++++++++-- include/linux/mfd/atmel-hlcdc.h | 1 + 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/mfd/atmel-hlcdc.c b/drivers/mfd/atmel-hlcdc.c index 4c4e35d404f3..0f83ad7ba15c 100644 --- a/drivers/mfd/atmel-hlcdc.c +++ b/drivers/mfd/atmel-hlcdc.c @@ -108,10 +108,19 @@ static int atmel_hlcdc_probe(struct platform_device *pdev) return PTR_ERR(hlcdc->periph_clk); } + /* + * Retrieve one of the primary clocks required for LCD operation: + * prefer sys_clk (for RGB/MIPI), and + * fall back to lvds_pll_clk (for LVDS) if needed. + */ hlcdc->sys_clk = devm_clk_get(dev, "sys_clk"); if (IS_ERR(hlcdc->sys_clk)) { - dev_err(dev, "failed to get system clock\n"); - return PTR_ERR(hlcdc->sys_clk); + hlcdc->sys_clk = NULL; + hlcdc->lvds_pll_clk = devm_clk_get(dev, "lvds_pll_clk"); + if (IS_ERR(hlcdc->lvds_pll_clk)) { + dev_err(dev, "Failed to obtain both the LCDC (generic) and LVDS PLL clocks\n"); + return PTR_ERR(hlcdc->lvds_pll_clk); + } } hlcdc->slow_clk = devm_clk_get(dev, "slow_clk"); diff --git a/include/linux/mfd/atmel-hlcdc.h b/include/linux/mfd/atmel-hlcdc.h index 80d675a03b39..07c2081867fd 100644 --- a/include/linux/mfd/atmel-hlcdc.h +++ b/include/linux/mfd/atmel-hlcdc.h @@ -75,6 +75,7 @@ */ struct atmel_hlcdc { struct regmap *regmap; + struct clk *lvds_pll_clk; struct clk *periph_clk; struct clk *sys_clk; struct clk *slow_clk; -- 2.25.1
