[PATCH V1 1/2] mmc: sdhci-msm: Add interconnect bandwidth scaling support

[Pradeep P V K <ppvk@codeaurora.org>]

Interconnect bandwidth scaling support is now added as a
part of OPP [1]. So, make sure interconnect driver is ready
before handling interconnect scaling.

This change is based on
[1] [Patch v8] Introduce OPP bandwidth bindings
(https://lkml.org/lkml/2020/5/12/493)

[2] [Patch v3] mmc: sdhci-msm: Fix error handling
for dev_pm_opp_of_add_table()
(https://lkml.org/lkml/2020/5/5/491)

Signed-off-by: Pradeep P V K <ppvk@codeaurora.org>
---
 drivers/mmc/host/sdhci-msm.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index b277dd7..bf95484 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -14,6 +14,7 @@
 #include <linux/slab.h>
 #include <linux/iopoll.h>
 #include <linux/regulator/consumer.h>
+#include <linux/interconnect.h>
 
 #include "sdhci-pltfm.h"
 #include "cqhci.h"
@@ -1999,6 +2000,7 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 	struct sdhci_pltfm_host *pltfm_host;
 	struct sdhci_msm_host *msm_host;
 	struct clk *clk;
+	struct icc_path *sdhc_path;
 	int ret;
 	u16 host_version, core_minor;
 	u32 core_version, config;
@@ -2070,6 +2072,20 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 	}
 	msm_host->bulk_clks[0].clk = clk;
 
+	/* Make sure that ICC driver is ready for interconnect bandwdith
+	 * scaling before registering the device for OPP.
+	 */
+	sdhc_path = of_icc_get(&pdev->dev, NULL);
+	ret = PTR_ERR_OR_ZERO(sdhc_path);
+	if (ret) {
+		if (ret == -EPROBE_DEFER)
+			dev_info(&pdev->dev, "defer icc path: %d\n", ret);
+		else
+			dev_err(&pdev->dev, "failed to get icc path:%d\n", ret);
+		goto bus_clk_disable;
+	}
+	icc_put(sdhc_path);
+
 	msm_host->opp_table = dev_pm_opp_set_clkname(&pdev->dev, "core");
 	if (IS_ERR(msm_host->opp_table)) {
 		ret = PTR_ERR(msm_host->opp_table);
-- 
1.9.1