media: camss: Add SM8250 bandwdith configuration support

Downstream makes some pretty explicit comments about voting for bus
bandwidth prior to camcc_camnoc_axi_clk_src. Working with camx downstream
also shows that the bandwidth vote is required to get that root clock
working.

Add a simple mechanism to declare set and unset named NOCs. Whereas the
objective is to enable the sm8250 specifically the code has been
implemented to allow setting of whatever NOCs different SoCs using this
driver may require.
Tested-by: NJulian Grahsl <jgrahsl@snap.com>
Signed-off-by: NBryan O'Donoghue <bryan.odonoghue@linaro.org>
Reviewed-by: NRobert Foss <robert.foss@linaro.org>
Signed-off-by: NHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@kernel.org>

drivers/media/platform/qcom/camss/camss.c

@@ -8,6 +8,7 @@
  * Copyright (C) 2015-2018 Linaro Ltd.
  */
 #include <linux/clk.h>
+#include <linux/interconnect.h>
 #include <linux/media-bus-format.h>
 #include <linux/media.h>
 #include <linux/module.h>
@@ -841,6 +842,29 @@ static const struct resources vfe_res_8250[] = {
 	},
 };
 
+static const struct resources_icc icc_res_sm8250[] = {
+	{
+		.name = "cam_ahb",
+		.icc_bw_tbl.avg = 38400,
+		.icc_bw_tbl.peak = 76800,
+	},
+	{
+		.name = "cam_hf_0_mnoc",
+		.icc_bw_tbl.avg = 2097152,
+		.icc_bw_tbl.peak = 2097152,
+	},
+	{
+		.name = "cam_sf_0_mnoc",
+		.icc_bw_tbl.avg = 0,
+		.icc_bw_tbl.peak = 2097152,
+	},
+	{
+		.name = "cam_sf_icp_mnoc",
+		.icc_bw_tbl.avg = 2097152,
+		.icc_bw_tbl.peak = 2097152,
+	},
+};
+
 /*
  * camss_add_clock_margin - Add margin to clock frequency rate
  * @rate: Clock frequency rate
@@ -1470,6 +1494,29 @@ static int camss_configure_pd(struct camss *camss)
 	return ret;
 }
 
+static int camss_icc_get(struct camss *camss)
+{
+	const struct resources_icc *icc_res;
+	int nbr_icc_paths = 0;
+	int i;
+
+	if (camss->version == CAMSS_8250) {
+		icc_res = &icc_res_sm8250[0];
+		nbr_icc_paths =	ICC_SM8250_COUNT;
+	}
+
+	for (i = 0; i < nbr_icc_paths; i++) {
+		camss->icc_path[i] = devm_of_icc_get(camss->dev,
+						     icc_res[i].name);
+		if (IS_ERR(camss->icc_path[i]))
+			return PTR_ERR(camss->icc_path[i]);
+
+		camss->icc_bw_tbl[i] = icc_res[i].icc_bw_tbl;
+	}
+
+	return 0;
+}
+
 /*
  * camss_probe - Probe CAMSS platform device
  * @pdev: Pointer to CAMSS platform device
@@ -1562,6 +1609,10 @@ static int camss_probe(struct platform_device *pdev)
 		goto err_cleanup;
 	}
 
+	ret = camss_icc_get(camss);
+	if (ret < 0)
+		goto err_cleanup;
+
 	ret = camss_init_subdevices(camss);
 	if (ret < 0)
 		goto err_cleanup;
@@ -1695,11 +1746,41 @@ MODULE_DEVICE_TABLE(of, camss_dt_match);
 
 static int __maybe_unused camss_runtime_suspend(struct device *dev)
 {
+	struct camss *camss = dev_get_drvdata(dev);
+	int nbr_icc_paths = 0;
+	int i;
+	int ret;
+
+	if (camss->version == CAMSS_8250)
+		nbr_icc_paths =	ICC_SM8250_COUNT;
+
+	for (i = 0; i < nbr_icc_paths; i++) {
+		ret = icc_set_bw(camss->icc_path[i], 0, 0);
+		if (ret)
+			return ret;
+	}
+
 	return 0;
 }
 
 static int __maybe_unused camss_runtime_resume(struct device *dev)
 {
+	struct camss *camss = dev_get_drvdata(dev);
+	int nbr_icc_paths = 0;
+	int i;
+	int ret;
+
+	if (camss->version == CAMSS_8250)
+		nbr_icc_paths =	ICC_SM8250_COUNT;
+
+	for (i = 0; i < nbr_icc_paths; i++) {
+		ret = icc_set_bw(camss->icc_path[i],
+				 camss->icc_bw_tbl[i].avg,
+				 camss->icc_bw_tbl[i].peak);
+		if (ret)
+			return ret;
+	}
+
 	return 0;
 }
 

drivers/media/platform/qcom/camss/camss.h

@@ -56,6 +56,16 @@ struct resources_ispif {
 	char *interrupt;
 };
 
+struct icc_bw_tbl {
+	u32 avg;
+	u32 peak;
+};
+
+struct resources_icc {
+	char *name;
+	struct icc_bw_tbl icc_bw_tbl;
+};
+
 enum pm_domain {
 	PM_DOMAIN_VFE0 = 0,
 	PM_DOMAIN_VFE1 = 1,
@@ -72,6 +82,11 @@ enum camss_version {
 	CAMSS_8250,
 };
 
+enum icc_count {
+	ICC_DEFAULT_COUNT = 0,
+	ICC_SM8250_COUNT = 4,
+};
+
 struct camss {
 	enum camss_version version;
 	struct v4l2_device v4l2_dev;
@@ -88,6 +103,8 @@ struct camss {
 	atomic_t ref_count;
 	struct device *genpd[PM_DOMAIN_GEN2_COUNT];
 	struct device_link *genpd_link[PM_DOMAIN_GEN2_COUNT];
+	struct icc_path *icc_path[ICC_SM8250_COUNT];
+	struct icc_bw_tbl icc_bw_tbl[ICC_SM8250_COUNT];
 };
 
 struct camss_camera_interface {