disp: msm: dsi: add support for phy/pll bypass

This change adds support for bypassing hw access in DSI PHY/PLL
drivers which enables the DSI driver to run on emulation
platforms that might be missing those modules.

Change-Id: I3e83155a79d60f2357606746214d776cefabd651
Signed-off-by: Rajkumar Subbiah <quic_rsubbia@quicinc.com>
Signed-off-by: Shamika Joshi <quic_shamjosh@quicinc.com>
Signed-off-by: Alex Danila <quic_eadanila@quicinc.com>

msm/dsi/dsi_pll.c

@@ -304,6 +304,8 @@ int dsi_pll_init(struct platform_device *pdev, struct dsi_pll_resource **pll)
 			pll_res->ssc_center = true;
 	}
 
+	pll_res->phy_pll_bypass = of_property_read_bool(pdev->dev.of_node,
+			"qcom,dsi-phy-pll-bypass");
 
 	if (dsi_pll_get_ioresources(pdev, &pll_res->pll_base, "pll_base")) {
 		DSI_PLL_ERR(pll_res, "Unable to remap pll base resources\n");
@@ -335,6 +337,9 @@ int dsi_pll_init(struct platform_device *pdev, struct dsi_pll_resource **pll)
 		return rc;
 	}
 
+	if (pll_res->phy_pll_bypass)
+		return 0;
+
 	rc = dsi_pll_clock_register(pdev, pll_res);
 	if (rc) {
 		DSI_PLL_ERR(pll_res, "clock register failed rc=%d\n", rc);