/*
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* omap-ocp2scp.c - transform ocp interface protocol to scp protocol
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*
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* Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* Author: Kishon Vijay Abraham I <kishon@ti.com>
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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*/
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/err.h>
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#include <linux/pm_runtime.h>
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#include <linux/of.h>
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#include <linux/of_platform.h>
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#define OCP2SCP_TIMING 0x18
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#define SYNC2_MASK 0xf
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static int ocp2scp_remove_devices(struct device *dev, void *c)
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{
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struct platform_device *pdev = to_platform_device(dev);
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platform_device_unregister(pdev);
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return 0;
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}
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static int omap_ocp2scp_probe(struct platform_device *pdev)
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{
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int ret;
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u32 reg;
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void __iomem *regs;
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struct resource *res;
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struct device_node *np = pdev->dev.of_node;
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if (np) {
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ret = of_platform_populate(np, NULL, NULL, &pdev->dev);
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if (ret) {
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dev_err(&pdev->dev,
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"failed to add resources for ocp2scp child\n");
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goto err0;
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}
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}
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pm_runtime_enable(&pdev->dev);
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/*
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* As per AM572x TRM: http://www.ti.com/lit/ug/spruhz6/spruhz6.pdf
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* under section 26.3.2.2, table 26-26 OCP2SCP TIMING Caution;
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* As per OMAP4430 TRM: http://www.ti.com/lit/ug/swpu231ap/swpu231ap.pdf
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* under section 23.12.6.2.2 , Table 23-1213 OCP2SCP TIMING Caution;
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* As per OMAP4460 TRM: http://www.ti.com/lit/ug/swpu235ab/swpu235ab.pdf
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* under section 23.12.6.2.2, Table 23-1213 OCP2SCP TIMING Caution;
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* As per OMAP543x TRM http://www.ti.com/lit/pdf/swpu249
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* under section 27.3.2.2, Table 27-27 OCP2SCP TIMING Caution;
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*
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* Read path of OCP2SCP is not working properly due to low reset value
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* of SYNC2 parameter in OCP2SCP. Suggested reset value is 0x6 or more.
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*/
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if (!of_device_is_compatible(np, "ti,am437x-ocp2scp")) {
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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regs = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(regs)) {
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ret = PTR_ERR(regs);
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goto err1;
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}
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pm_runtime_get_sync(&pdev->dev);
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reg = readl_relaxed(regs + OCP2SCP_TIMING);
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reg &= ~(SYNC2_MASK);
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reg |= 0x6;
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writel_relaxed(reg, regs + OCP2SCP_TIMING);
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pm_runtime_put_sync(&pdev->dev);
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}
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return 0;
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err1:
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pm_runtime_disable(&pdev->dev);
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err0:
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device_for_each_child(&pdev->dev, NULL, ocp2scp_remove_devices);
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return ret;
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}
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static int omap_ocp2scp_remove(struct platform_device *pdev)
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{
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pm_runtime_disable(&pdev->dev);
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device_for_each_child(&pdev->dev, NULL, ocp2scp_remove_devices);
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return 0;
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}
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#ifdef CONFIG_OF
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static const struct of_device_id omap_ocp2scp_id_table[] = {
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{ .compatible = "ti,omap-ocp2scp" },
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{ .compatible = "ti,am437x-ocp2scp" },
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{}
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};
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MODULE_DEVICE_TABLE(of, omap_ocp2scp_id_table);
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#endif
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static struct platform_driver omap_ocp2scp_driver = {
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.probe = omap_ocp2scp_probe,
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.remove = omap_ocp2scp_remove,
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.driver = {
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.name = "omap-ocp2scp",
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.of_match_table = of_match_ptr(omap_ocp2scp_id_table),
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},
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};
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module_platform_driver(omap_ocp2scp_driver);
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MODULE_ALIAS("platform:omap-ocp2scp");
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MODULE_AUTHOR("Texas Instruments Inc.");
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MODULE_DESCRIPTION("OMAP OCP2SCP driver");
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MODULE_LICENSE("GPL v2");
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