interconnect: qcom: icc-rpmh: Get parent's regmap for nested NoCs

Since commit 57eb14779dfd ("interconnect: qcom: icc-rpmh: Support child
NoC device probe") the icc-rpmh driver supports initializing child NoCs,
but those child NoCs also need to be able to get the parent's regmap in
order to enable QoS.

Change the driver to support that and support programming QoS register.

Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20251114-sm6350-icc-qos-v2-2-6af348cb9c69@fairphone.com
Signed-off-by: Georgi Djakov <djakov@kernel.org>

diff --git a/drivers/interconnect/qcom/icc-rpmh.c b/drivers/interconnect/qcom/icc-rpmh.c
index f90c29111f48ef810a8949ecd25bfbacf20805cb..3b445acefece7f1b3620ad921617694d2105e37f 100644 (file)
--- a/drivers/interconnect/qcom/icc-rpmh.c
+++ b/drivers/interconnect/qcom/icc-rpmh.c
@@ -308,14 +308,19 @@ int qcom_icc_rpmh_probe(struct platform_device *pdev)
                struct resource *res;
                void __iomem *base;
 
-               base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
-               if (IS_ERR(base))
-                       goto skip_qos_config;
-
-               qp->regmap = devm_regmap_init_mmio(dev, base, desc->config);
-               if (IS_ERR(qp->regmap)) {
-                       dev_info(dev, "Skipping QoS, regmap failed; %ld\n", PTR_ERR(qp->regmap));
-                       goto skip_qos_config;
+               /* Try parent's regmap first */
+               qp->regmap = dev_get_regmap(dev->parent, NULL);
+               if (!qp->regmap) {
+                       base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+                       if (IS_ERR(base))
+                               goto skip_qos_config;
+
+                       qp->regmap = devm_regmap_init_mmio(dev, base, desc->config);
+                       if (IS_ERR(qp->regmap)) {
+                               dev_info(dev, "Skipping QoS, regmap failed; %ld\n",
+                                        PTR_ERR(qp->regmap));
+                               goto skip_qos_config;
+                       }
                }
 
                qp->num_clks = devm_clk_bulk_get_all(qp->dev, &qp->clks);