117 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * omap-ocp2scp.c - transform ocp interface protocol to scp protocol4 *5 * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com6 * Author: Kishon Vijay Abraham I <kishon@ti.com>7 */8 9#include <linux/io.h>10#include <linux/module.h>11#include <linux/platform_device.h>12#include <linux/err.h>13#include <linux/pm_runtime.h>14#include <linux/of.h>15#include <linux/of_platform.h>16 17#define OCP2SCP_TIMING 0x1818#define SYNC2_MASK 0xf19 20static int ocp2scp_remove_devices(struct device *dev, void *c)21{22 struct platform_device *pdev = to_platform_device(dev);23 24 platform_device_unregister(pdev);25 26 return 0;27}28 29static int omap_ocp2scp_probe(struct platform_device *pdev)30{31 int ret;32 u32 reg;33 void __iomem *regs;34 struct resource *res;35 struct device_node *np = pdev->dev.of_node;36 37 if (np) {38 ret = of_platform_populate(np, NULL, NULL, &pdev->dev);39 if (ret) {40 dev_err(&pdev->dev,41 "failed to add resources for ocp2scp child\n");42 goto err0;43 }44 }45 46 pm_runtime_enable(&pdev->dev);47 /*48 * As per AM572x TRM: http://www.ti.com/lit/ug/spruhz6/spruhz6.pdf49 * under section 26.3.2.2, table 26-26 OCP2SCP TIMING Caution;50 * As per OMAP4430 TRM: http://www.ti.com/lit/ug/swpu231ap/swpu231ap.pdf51 * under section 23.12.6.2.2 , Table 23-1213 OCP2SCP TIMING Caution;52 * As per OMAP4460 TRM: http://www.ti.com/lit/ug/swpu235ab/swpu235ab.pdf53 * under section 23.12.6.2.2, Table 23-1213 OCP2SCP TIMING Caution;54 * As per OMAP543x TRM http://www.ti.com/lit/pdf/swpu24955 * under section 27.3.2.2, Table 27-27 OCP2SCP TIMING Caution;56 *57 * Read path of OCP2SCP is not working properly due to low reset value58 * of SYNC2 parameter in OCP2SCP. Suggested reset value is 0x6 or more.59 */60 if (!of_device_is_compatible(np, "ti,am437x-ocp2scp")) {61 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);62 regs = devm_ioremap_resource(&pdev->dev, res);63 if (IS_ERR(regs)) {64 ret = PTR_ERR(regs);65 goto err1;66 }67 68 pm_runtime_get_sync(&pdev->dev);69 reg = readl_relaxed(regs + OCP2SCP_TIMING);70 reg &= ~(SYNC2_MASK);71 reg |= 0x6;72 writel_relaxed(reg, regs + OCP2SCP_TIMING);73 pm_runtime_put_sync(&pdev->dev);74 }75 76 return 0;77 78err1:79 pm_runtime_disable(&pdev->dev);80 81err0:82 device_for_each_child(&pdev->dev, NULL, ocp2scp_remove_devices);83 84 return ret;85}86 87static void omap_ocp2scp_remove(struct platform_device *pdev)88{89 pm_runtime_disable(&pdev->dev);90 device_for_each_child(&pdev->dev, NULL, ocp2scp_remove_devices);91}92 93#ifdef CONFIG_OF94static const struct of_device_id omap_ocp2scp_id_table[] = {95 { .compatible = "ti,omap-ocp2scp" },96 { .compatible = "ti,am437x-ocp2scp" },97 {}98};99MODULE_DEVICE_TABLE(of, omap_ocp2scp_id_table);100#endif101 102static struct platform_driver omap_ocp2scp_driver = {103 .probe = omap_ocp2scp_probe,104 .remove_new = omap_ocp2scp_remove,105 .driver = {106 .name = "omap-ocp2scp",107 .of_match_table = of_match_ptr(omap_ocp2scp_id_table),108 },109};110 111module_platform_driver(omap_ocp2scp_driver);112 113MODULE_ALIAS("platform:omap-ocp2scp");114MODULE_AUTHOR("Texas Instruments Inc.");115MODULE_DESCRIPTION("OMAP OCP2SCP driver");116MODULE_LICENSE("GPL v2");117