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cdf61240e1
As per the TRMs of AM572x, OMAP4430, OMAP4460, OMAP543x, the value of SYNC2 must be set to 0x6 in order to ensure correct operation. So modified the SYNC2 value of OCP2SCP TIMING register to 0x6 in all the platforms that use OCP2SCP driver except AM437x. Also introduced a new compatible property since we don't want to modify the OCP2SCP TIMING register for AM437x. The sections in TRM where the above caution can be found is mentioned below. AM572x TRM SPRUHZ6 (http://www.ti.com/lit/ug/spruhz6/spruhz6.pdf) under section 26.3.2.2, table 26-26. OMAP4430 TRM SWPU231AP (http://www.ti.com/lit/ug/swpu231ap/swpu231ap.pdf) under section 23.12.6.2.2 , Table 23-1213. OMAP4460 TRM SWPU235AB (http://www.ti.com/lit/ug/swpu235ab/swpu235ab.pdf) under section 23.12.6.2.2, Table 23-1213. OMAP543x TRM SWPU249 (http://www.ti.com/lit/pdf/swpu249) under section 27.3.2.2, Table 27-27. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Praneeth Bajjuri <praneeth@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
123 lines
3.4 KiB
C
123 lines
3.4 KiB
C
/*
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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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goto err0;
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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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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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