[PATCH] PCIe: qcom: Add support to control pipe clk mux

From: Prasad Malisetty <pmaliset@codeaurora.org>
To: Andy Gross <agross@kernel.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Stanimir Varbanov <svarbanov@mm-sol.com>,
	Rob Herring <robh+dt@kernel.org>,
	Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
	mgautam@codeaurora.org, swboyd@chromium.org,
	dianders@chromium.org, mka@chromium.org,
	Prasad Malisetty <pmaliset@codeaurora.org>
Subject: [PATCH] PCIe: qcom: Add support to control pipe clk mux
Date: Sun,  9 May 2021 06:11:00 +0530	[thread overview]
Message-ID: <1620520860-8589-1-git-send-email-pmaliset@codeaurora.org> (raw)

PCIe driver needs to toggle between bi_tcxo and phy pipe
clock as part of its LPM sequence. This is done by setting
pipe_clk/ref_clk_src as parent of pipe_clk_src after phy init

Dependent on below change:

	https://lore.kernel.org/patchwork/patch/1422499/

Signed-off-by: Prasad Malisetty <pmaliset@codeaurora.org>
---
 drivers/pci/controller/dwc/pcie-qcom.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 8a7a300..a9f69e8 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -9,6 +9,7 @@
  */
 
 #include <linux/clk.h>
+#include <linux/clk-provider.h>
 #include <linux/crc8.h>
 #include <linux/delay.h>
 #include <linux/gpio/consumer.h>
@@ -166,6 +167,9 @@ struct qcom_pcie_resources_2_7_0 {
 	struct regulator_bulk_data supplies[2];
 	struct reset_control *pci_reset;
 	struct clk *pipe_clk;
+	struct clk *pipe_clk_src;
+	struct clk *pipe_ext_src;
+	struct clk *ref_clk_src;
 };
 
 union qcom_pcie_resources {
@@ -1168,7 +1172,19 @@ static int qcom_pcie_get_resources_2_7_0(struct qcom_pcie *pcie)
 		return ret;
 
 	res->pipe_clk = devm_clk_get(dev, "pipe");
-	return PTR_ERR_OR_ZERO(res->pipe_clk);
+	if (IS_ERR(res->pipe_clk))
+		return PTR_ERR(res->pipe_clk);
+
+	res->pipe_clk_src = devm_clk_get(dev, "pipe_src");
+	if (IS_ERR(res->pipe_clk_src))
+		return PTR_ERR(res->pipe_clk_src);
+
+	res->pipe_ext_src = devm_clk_get(dev, "pipe_ext");
+	if (IS_ERR(res->pipe_ext_src))
+		return PTR_ERR(res->pipe_ext_src);
+
+	res->ref_clk_src = devm_clk_get(dev, "ref");
+	return PTR_ERR_OR_ZERO(res->ref_clk_src);
 }
 
 static int qcom_pcie_init_2_7_0(struct qcom_pcie *pcie)
@@ -1255,6 +1271,11 @@ static void qcom_pcie_deinit_2_7_0(struct qcom_pcie *pcie)
 static int qcom_pcie_post_init_2_7_0(struct qcom_pcie *pcie)
 {
 	struct qcom_pcie_resources_2_7_0 *res = &pcie->res.v2_7_0;
+	struct dw_pcie *pci = pcie->pci;
+	struct device *dev = pci->dev;
+
+	if (of_device_is_compatible(dev->of_node, "qcom,pcie-sc7280"))
+		clk_set_parent(res->pipe_clk_src, res->pipe_ext_src);
 
 	return clk_prepare_enable(res->pipe_clk);
 }
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

