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path: root/drivers/bus/omap-ocp2scp.c
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Diffstat (limited to 'drivers/bus/omap-ocp2scp.c')
-rw-r--r--drivers/bus/omap-ocp2scp.c34
1 files changed, 34 insertions, 0 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);