/* * 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)) { ret = PTR_ERR(regs); goto err1; } 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; err1: pm_runtime_disable(&pdev->dev); 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");