[PATCH 2/3] mfd: atmel-hlcdc: fetch LVDS PLL clock for LVDS display

[Manikandan Muralidharan <manikandan.m@xxxxxxxxxxxxx>]

The XLCDC IP supports DSI, parallel RGB and LVDS Display.
sys_clk(Generic clock) is used for DSI and Parallel RGB displays;
And LVDS PLL is used with LVDS displays.
obtain anyone of the clocks for the LCD to operate

Signed-off-by: Manikandan Muralidharan <manikandan.m@xxxxxxxxxxxxx>
Signed-off-by: Dharma Balasubiramani <dharma.b@xxxxxxxxxxxxx>
---
 drivers/mfd/atmel-hlcdc.c       | 16 ++++++++++++++--
 include/linux/mfd/atmel-hlcdc.h |  1 +
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/mfd/atmel-hlcdc.c b/drivers/mfd/atmel-hlcdc.c
index 4c4e35d404f3..60b0b766459e 100644
--- a/drivers/mfd/atmel-hlcdc.c
+++ b/drivers/mfd/atmel-hlcdc.c
@@ -108,10 +108,22 @@ static int atmel_hlcdc_probe(struct platform_device *pdev)
 		return PTR_ERR(hlcdc->periph_clk);
 	}
 
+	/*
+	 * Obtain one of the main clocks (GCK / LVDS PLL) required by the
+	 * LCD to function,
+	 * GCK for Parallel RGB and MIPI displays;
+	 * LVDS PLL for LVDS displays.
+	 */
+	hlcdc->sys_clk = NULL;
+	hlcdc->lvds_pll_clk = NULL;
 	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);
+		dev_dbg(dev, "failed to get system clock\n");
+		hlcdc->lvds_pll_clk = devm_clk_get(dev, "lvds_pll_clk");
+		if (IS_ERR(hlcdc->lvds_pll_clk)) {
+			dev_err(dev, "failed to get LVDS PLL clock\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