[PATCH v5 5/8] drm/msm/dsi: 10nm PHY: Get ref clock from the DT

[Matthias Kaehlcke <mka@xxxxxxxxxxxx>]

Get the ref clock of the PHY from the device tree instead of
hardcoding its name and rate.

Note: This change could break old out-of-tree DTS files that
use the 10nm PHY

Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
---
Changes in v5:
- pass the ref clock name to _register() instead of storing a point
  to the clk object in the PLL data structure

Changes in v4:
- none

Changes in v3:
- fixed check for EPROBE_DEFER
- added note to commit message about breaking old DTS files
- added 'Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>' tag

Changes in v2:
- remove anonymous array in clk_init_data assignment
- log error code if devm_clk_get() fails
- don't log devm_clk_get() failures for -EPROBE_DEFER
- updated commit message
---
 drivers/gpu/drm/msm/dsi/pll/dsi_pll_10nm.c | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/msm/dsi/pll/dsi_pll_10nm.c b/drivers/gpu/drm/msm/dsi/pll/dsi_pll_10nm.c
index 4c03f0b7343ed..adbe5395f4f38 100644
--- a/drivers/gpu/drm/msm/dsi/pll/dsi_pll_10nm.c
+++ b/drivers/gpu/drm/msm/dsi/pll/dsi_pll_10nm.c
@@ -625,12 +625,14 @@ static void dsi_pll_10nm_destroy(struct msm_dsi_pll *pll)
  * state to follow the master PLL's divider/mux state. Therefore, we don't
  * require special clock ops that also configure the slave PLL registers
  */
-static int pll_10nm_register(struct dsi_pll_10nm *pll_10nm)
+static int pll_10nm_register(struct dsi_pll_10nm *pll_10nm,
+			     const char *ref_clk_name)
 {
 	char clk_name[32], parent[32], vco_name[32];
 	char parent2[32], parent3[32], parent4[32];
+
 	struct clk_init_data vco_init = {
-		.parent_names = (const char *[]){ "xo" },
+		.parent_names = &ref_clk_name,
 		.num_parents = 1,
 		.name = vco_name,
 		.flags = CLK_IGNORE_UNUSED,
@@ -771,6 +773,8 @@ struct msm_dsi_pll *msm_dsi_pll_10nm_init(struct platform_device *pdev, int id)
 {
 	struct dsi_pll_10nm *pll_10nm;
 	struct msm_dsi_pll *pll;
+	struct clk *vco_ref_clk;
+	const char *vco_ref_clk_name;
 	int ret;
 
 	if (!pdev)
@@ -786,6 +790,16 @@ struct msm_dsi_pll *msm_dsi_pll_10nm_init(struct platform_device *pdev, int id)
 	pll_10nm->id = id;
 	pll_10nm_list[id] = pll_10nm;
 
+	vco_ref_clk = devm_clk_get(&pdev->dev, "ref");
+	if (IS_ERR(vco_ref_clk)) {
+		ret = PTR_ERR(vco_ref_clk);
+		if (ret != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "couldn't get 'ref' clock: %d\n",
+				ret);
+		return ERR_PTR(ret);
+	}
+	vco_ref_clk_name = __clk_get_name(vco_ref_clk);
+
 	pll_10nm->phy_cmn_mmio = msm_ioremap(pdev, "dsi_phy", "DSI_PHY");
 	if (IS_ERR_OR_NULL(pll_10nm->phy_cmn_mmio)) {
 		dev_err(&pdev->dev, "failed to map CMN PHY base\n");
@@ -811,7 +825,7 @@ struct msm_dsi_pll *msm_dsi_pll_10nm_init(struct platform_device *pdev, int id)
 
 	pll_10nm->vco_delay = 1;
 
-	ret = pll_10nm_register(pll_10nm);
+	ret = pll_10nm_register(pll_10nm, vco_ref_clk_name);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to register PLL: %d\n", ret);
 		return ERR_PTR(ret);
-- 
2.20.1.415.g653613c723-goog