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Kishon Vijay Abraham I26a84b32012-08-22 14:10:02 +05301/*
2 * omap-ocp2scp.c - transform ocp interface protocol to scp protocol
3 *
4 * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * Author: Kishon Vijay Abraham I <kishon@ti.com>
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 */
18
Kishon Vijay Abraham Icdf61242015-03-17 16:54:51 +053019#include <linux/io.h>
Kishon Vijay Abraham I26a84b32012-08-22 14:10:02 +053020#include <linux/module.h>
21#include <linux/platform_device.h>
22#include <linux/err.h>
23#include <linux/pm_runtime.h>
24#include <linux/of.h>
25#include <linux/of_platform.h>
26
Kishon Vijay Abraham Icdf61242015-03-17 16:54:51 +053027#define OCP2SCP_TIMING 0x18
28#define SYNC2_MASK 0xf
29
Kishon Vijay Abraham I26a84b32012-08-22 14:10:02 +053030static int ocp2scp_remove_devices(struct device *dev, void *c)
31{
32 struct platform_device *pdev = to_platform_device(dev);
33
34 platform_device_unregister(pdev);
35
36 return 0;
37}
38
Greg Kroah-Hartman0fe763c2012-12-21 15:14:44 -080039static int omap_ocp2scp_probe(struct platform_device *pdev)
Kishon Vijay Abraham I26a84b32012-08-22 14:10:02 +053040{
Kishon Vijay Abraham I01333702012-11-02 13:44:46 +053041 int ret;
Kishon Vijay Abraham Icdf61242015-03-17 16:54:51 +053042 u32 reg;
43 void __iomem *regs;
44 struct resource *res;
Kishon Vijay Abraham I01333702012-11-02 13:44:46 +053045 struct device_node *np = pdev->dev.of_node;
Kishon Vijay Abraham I26a84b32012-08-22 14:10:02 +053046
47 if (np) {
48 ret = of_platform_populate(np, NULL, NULL, &pdev->dev);
49 if (ret) {
Kishon Vijay Abraham I01333702012-11-02 13:44:46 +053050 dev_err(&pdev->dev,
51 "failed to add resources for ocp2scp child\n");
Kishon Vijay Abraham I26a84b32012-08-22 14:10:02 +053052 goto err0;
53 }
54 }
Kishon Vijay Abraham I01333702012-11-02 13:44:46 +053055
Kishon Vijay Abraham I26a84b32012-08-22 14:10:02 +053056 pm_runtime_enable(&pdev->dev);
Kishon Vijay Abraham Icdf61242015-03-17 16:54:51 +053057 /*
58 * As per AM572x TRM: http://www.ti.com/lit/ug/spruhz6/spruhz6.pdf
59 * under section 26.3.2.2, table 26-26 OCP2SCP TIMING Caution;
60 * As per OMAP4430 TRM: http://www.ti.com/lit/ug/swpu231ap/swpu231ap.pdf
61 * under section 23.12.6.2.2 , Table 23-1213 OCP2SCP TIMING Caution;
62 * As per OMAP4460 TRM: http://www.ti.com/lit/ug/swpu235ab/swpu235ab.pdf
63 * under section 23.12.6.2.2, Table 23-1213 OCP2SCP TIMING Caution;
64 * As per OMAP543x TRM http://www.ti.com/lit/pdf/swpu249
65 * under section 27.3.2.2, Table 27-27 OCP2SCP TIMING Caution;
66 *
67 * Read path of OCP2SCP is not working properly due to low reset value
68 * of SYNC2 parameter in OCP2SCP. Suggested reset value is 0x6 or more.
69 */
70 if (!of_device_is_compatible(np, "ti,am437x-ocp2scp")) {
71 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
72 regs = devm_ioremap_resource(&pdev->dev, res);
Kishon Vijay Abraham I672647a2017-07-11 15:46:38 +053073 if (IS_ERR(regs)) {
74 ret = PTR_ERR(regs);
75 goto err1;
76 }
Kishon Vijay Abraham Icdf61242015-03-17 16:54:51 +053077
78 pm_runtime_get_sync(&pdev->dev);
79 reg = readl_relaxed(regs + OCP2SCP_TIMING);
80 reg &= ~(SYNC2_MASK);
81 reg |= 0x6;
82 writel_relaxed(reg, regs + OCP2SCP_TIMING);
83 pm_runtime_put_sync(&pdev->dev);
84 }
Kishon Vijay Abraham I26a84b32012-08-22 14:10:02 +053085
86 return 0;
87
Kishon Vijay Abraham I672647a2017-07-11 15:46:38 +053088err1:
89 pm_runtime_disable(&pdev->dev);
90
Kishon Vijay Abraham I26a84b32012-08-22 14:10:02 +053091err0:
92 device_for_each_child(&pdev->dev, NULL, ocp2scp_remove_devices);
93
94 return ret;
95}
96
Greg Kroah-Hartman0fe763c2012-12-21 15:14:44 -080097static int omap_ocp2scp_remove(struct platform_device *pdev)
Kishon Vijay Abraham I26a84b32012-08-22 14:10:02 +053098{
99 pm_runtime_disable(&pdev->dev);
100 device_for_each_child(&pdev->dev, NULL, ocp2scp_remove_devices);
101
102 return 0;
103}
104
105#ifdef CONFIG_OF
106static const struct of_device_id omap_ocp2scp_id_table[] = {
107 { .compatible = "ti,omap-ocp2scp" },
Kishon Vijay Abraham Icdf61242015-03-17 16:54:51 +0530108 { .compatible = "ti,am437x-ocp2scp" },
Kishon Vijay Abraham I26a84b32012-08-22 14:10:02 +0530109 {}
110};
Kishon Vijay Abraham I46ca6812012-08-23 23:10:26 +0530111MODULE_DEVICE_TABLE(of, omap_ocp2scp_id_table);
Kishon Vijay Abraham I26a84b32012-08-22 14:10:02 +0530112#endif
113
114static struct platform_driver omap_ocp2scp_driver = {
115 .probe = omap_ocp2scp_probe,
Greg Kroah-Hartman0fe763c2012-12-21 15:14:44 -0800116 .remove = omap_ocp2scp_remove,
Kishon Vijay Abraham I26a84b32012-08-22 14:10:02 +0530117 .driver = {
118 .name = "omap-ocp2scp",
Kishon Vijay Abraham I26a84b32012-08-22 14:10:02 +0530119 .of_match_table = of_match_ptr(omap_ocp2scp_id_table),
120 },
121};
122
123module_platform_driver(omap_ocp2scp_driver);
124
Axel Lin7ef71b72015-09-25 08:51:42 +0800125MODULE_ALIAS("platform:omap-ocp2scp");
Kishon Vijay Abraham I26a84b32012-08-22 14:10:02 +0530126MODULE_AUTHOR("Texas Instruments Inc.");
127MODULE_DESCRIPTION("OMAP OCP2SCP driver");
128MODULE_LICENSE("GPL v2");