2 files changed, 36 insertions, 1 deletions

diff --git a/drivers/bus/omap-ocp2scp.c b/drivers/bus/omap-ocp2scp.c
index 723ec06ad2c8..9f1856948758 100644
--- a/drivers/bus/omap-ocp2scp.c
+++ b/drivers/bus/omap-ocp2scp.c
@@ -16,6 +16,7 @@
  *
  */
 
+#include <linux/io.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/err.h>
@@ -23,6 +24,9 @@
 #include <linux/of.h>
 #include <linux/of_platform.h>
 
+#define OCP2SCP_TIMING 0x18
+#define SYNC2_MASK 0xf
+
 static int ocp2scp_remove_devices(struct device *dev, void *c)
 {
         struct platform_device *pdev = to_platform_device(dev);
@@ -35,6 +39,9 @@ static int ocp2scp_remove_devices(struct device *dev, void *c)
 static int omap_ocp2scp_probe(struct platform_device *pdev)
 {
         int ret;
+        u32 reg;
+        void __iomem *regs;
+        struct resource *res;
         struct device_node *np = pdev->dev.of_node;
 
         if (np) {
@@ -47,6 +54,32 @@ static int omap_ocp2scp_probe(struct platform_device *pdev)
         }
 
         pm_runtime_enable(&pdev->dev);
+        /*
+         * As per AM572x TRM: http://www.ti.com/lit/ug/spruhz6/spruhz6.pdf
+         * under section 26.3.2.2, table 26-26 OCP2SCP TIMING Caution;
+         * As per OMAP4430 TRM: http://www.ti.com/lit/ug/swpu231ap/swpu231ap.pdf
+         * under section 23.12.6.2.2 , Table 23-1213 OCP2SCP TIMING Caution;
+         * As per OMAP4460 TRM: http://www.ti.com/lit/ug/swpu235ab/swpu235ab.pdf
+         * under section 23.12.6.2.2, Table 23-1213 OCP2SCP TIMING Caution;
+         * As per OMAP543x TRM http://www.ti.com/lit/pdf/swpu249
+         * under section 27.3.2.2, Table 27-27 OCP2SCP TIMING Caution;
+         *
+         * Read path of OCP2SCP is not working properly due to low reset value
+         * of SYNC2 parameter in OCP2SCP. Suggested reset value is 0x6 or more.
+         */
+        if (!of_device_is_compatible(np, "ti,am437x-ocp2scp")) {
+                res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+                regs = devm_ioremap_resource(&pdev->dev, res);
+                if (IS_ERR(regs))
+                        goto err0;
+
+                pm_runtime_get_sync(&pdev->dev);
+                reg = readl_relaxed(regs + OCP2SCP_TIMING);
+                reg &= ~(SYNC2_MASK);
+                reg |= 0x6;
+                writel_relaxed(reg, regs + OCP2SCP_TIMING);
+                pm_runtime_put_sync(&pdev->dev);
+        }
 
         return 0;
 
@@ -67,6 +100,7 @@ static int omap_ocp2scp_remove(struct platform_device *pdev)
 #ifdef CONFIG_OF
 static const struct of_device_id omap_ocp2scp_id_table[] = {
         { .compatible = "ti,omap-ocp2scp" },
+        { .compatible = "ti,am437x-ocp2scp" },
         {}
 };
 MODULE_DEVICE_TABLE(of, omap_ocp2scp_id_table);
diff --git a/drivers/cpuidle/cpuidle-exynos.c b/drivers/cpuidle/cpuidle-exynos.c
index 0c06ea2f50bb..b5f0a9cc8185 100644
--- a/drivers/cpuidle/cpuidle-exynos.c
+++ b/drivers/cpuidle/cpuidle-exynos.c
@@ -116,7 +116,8 @@ static int exynos_cpuidle_probe(struct platform_device *pdev)
 {
         int ret;
 
-        if (of_machine_is_compatible("samsung,exynos4210")) {
+        if (IS_ENABLED(CONFIG_SMP) &&
+            of_machine_is_compatible("samsung,exynos4210")) {
                 exynos_cpuidle_pdata = pdev->dev.platform_data;
 
                 ret = cpuidle_register(&exynos_coupled_idle_driver,