Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / bus / omap-ocp2scp.c

diff --git a/kernel/drivers/bus/omap-ocp2scp.c b/kernel/drivers/bus/omap-ocp2scp.c
new file mode 100644 (file)
index 0000000..9f18569
--- /dev/null
+++ b/kernel/drivers/bus/omap-ocp2scp.c
@@ -0,0 +1,123 @@
+/*
+ * omap-ocp2scp.c - transform ocp interface protocol to scp protocol
+ *
+ * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * Author: Kishon Vijay Abraham I <kishon@ti.com>
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/pm_runtime.h>
+#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);
+
+       platform_device_unregister(pdev);
+
+       return 0;
+}
+
+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) {
+               ret = of_platform_populate(np, NULL, NULL, &pdev->dev);
+               if (ret) {
+                       dev_err(&pdev->dev,
+                           "failed to add resources for ocp2scp child\n");
+                       goto err0;
+               }
+       }
+
+       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;
+
+err0:
+       device_for_each_child(&pdev->dev, NULL, ocp2scp_remove_devices);
+
+       return ret;
+}
+
+static int omap_ocp2scp_remove(struct platform_device *pdev)
+{
+       pm_runtime_disable(&pdev->dev);
+       device_for_each_child(&pdev->dev, NULL, ocp2scp_remove_devices);
+
+       return 0;
+}
+
+#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);
+#endif
+
+static struct platform_driver omap_ocp2scp_driver = {
+       .probe          = omap_ocp2scp_probe,
+       .remove         = omap_ocp2scp_remove,
+       .driver         = {
+               .name   = "omap-ocp2scp",
+               .of_match_table = of_match_ptr(omap_ocp2scp_id_table),
+       },
+};
+
+module_platform_driver(omap_ocp2scp_driver);
+
+MODULE_ALIAS("platform: omap-ocp2scp");
+MODULE_AUTHOR("Texas Instruments Inc.");
+MODULE_DESCRIPTION("OMAP OCP2SCP driver");
+MODULE_LICENSE("GPL v2");