1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * omap-ocp2scp.c - transform ocp interface protocol to scp protocol
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com
6*4882a593Smuzhiyun * Author: Kishon Vijay Abraham I <kishon@ti.com>
7*4882a593Smuzhiyun */
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun #include <linux/io.h>
10*4882a593Smuzhiyun #include <linux/module.h>
11*4882a593Smuzhiyun #include <linux/platform_device.h>
12*4882a593Smuzhiyun #include <linux/err.h>
13*4882a593Smuzhiyun #include <linux/pm_runtime.h>
14*4882a593Smuzhiyun #include <linux/of.h>
15*4882a593Smuzhiyun #include <linux/of_platform.h>
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun #define OCP2SCP_TIMING 0x18
18*4882a593Smuzhiyun #define SYNC2_MASK 0xf
19*4882a593Smuzhiyun
ocp2scp_remove_devices(struct device * dev,void * c)20*4882a593Smuzhiyun static int ocp2scp_remove_devices(struct device *dev, void *c)
21*4882a593Smuzhiyun {
22*4882a593Smuzhiyun struct platform_device *pdev = to_platform_device(dev);
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun platform_device_unregister(pdev);
25*4882a593Smuzhiyun
26*4882a593Smuzhiyun return 0;
27*4882a593Smuzhiyun }
28*4882a593Smuzhiyun
omap_ocp2scp_probe(struct platform_device * pdev)29*4882a593Smuzhiyun static int omap_ocp2scp_probe(struct platform_device *pdev)
30*4882a593Smuzhiyun {
31*4882a593Smuzhiyun int ret;
32*4882a593Smuzhiyun u32 reg;
33*4882a593Smuzhiyun void __iomem *regs;
34*4882a593Smuzhiyun struct resource *res;
35*4882a593Smuzhiyun struct device_node *np = pdev->dev.of_node;
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun if (np) {
38*4882a593Smuzhiyun ret = of_platform_populate(np, NULL, NULL, &pdev->dev);
39*4882a593Smuzhiyun if (ret) {
40*4882a593Smuzhiyun dev_err(&pdev->dev,
41*4882a593Smuzhiyun "failed to add resources for ocp2scp child\n");
42*4882a593Smuzhiyun goto err0;
43*4882a593Smuzhiyun }
44*4882a593Smuzhiyun }
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun pm_runtime_enable(&pdev->dev);
47*4882a593Smuzhiyun /*
48*4882a593Smuzhiyun * As per AM572x TRM: http://www.ti.com/lit/ug/spruhz6/spruhz6.pdf
49*4882a593Smuzhiyun * under section 26.3.2.2, table 26-26 OCP2SCP TIMING Caution;
50*4882a593Smuzhiyun * As per OMAP4430 TRM: http://www.ti.com/lit/ug/swpu231ap/swpu231ap.pdf
51*4882a593Smuzhiyun * under section 23.12.6.2.2 , Table 23-1213 OCP2SCP TIMING Caution;
52*4882a593Smuzhiyun * As per OMAP4460 TRM: http://www.ti.com/lit/ug/swpu235ab/swpu235ab.pdf
53*4882a593Smuzhiyun * under section 23.12.6.2.2, Table 23-1213 OCP2SCP TIMING Caution;
54*4882a593Smuzhiyun * As per OMAP543x TRM http://www.ti.com/lit/pdf/swpu249
55*4882a593Smuzhiyun * under section 27.3.2.2, Table 27-27 OCP2SCP TIMING Caution;
56*4882a593Smuzhiyun *
57*4882a593Smuzhiyun * Read path of OCP2SCP is not working properly due to low reset value
58*4882a593Smuzhiyun * of SYNC2 parameter in OCP2SCP. Suggested reset value is 0x6 or more.
59*4882a593Smuzhiyun */
60*4882a593Smuzhiyun if (!of_device_is_compatible(np, "ti,am437x-ocp2scp")) {
61*4882a593Smuzhiyun res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
62*4882a593Smuzhiyun regs = devm_ioremap_resource(&pdev->dev, res);
63*4882a593Smuzhiyun if (IS_ERR(regs)) {
64*4882a593Smuzhiyun ret = PTR_ERR(regs);
65*4882a593Smuzhiyun goto err1;
66*4882a593Smuzhiyun }
67*4882a593Smuzhiyun
68*4882a593Smuzhiyun pm_runtime_get_sync(&pdev->dev);
69*4882a593Smuzhiyun reg = readl_relaxed(regs + OCP2SCP_TIMING);
70*4882a593Smuzhiyun reg &= ~(SYNC2_MASK);
71*4882a593Smuzhiyun reg |= 0x6;
72*4882a593Smuzhiyun writel_relaxed(reg, regs + OCP2SCP_TIMING);
73*4882a593Smuzhiyun pm_runtime_put_sync(&pdev->dev);
74*4882a593Smuzhiyun }
75*4882a593Smuzhiyun
76*4882a593Smuzhiyun return 0;
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun err1:
79*4882a593Smuzhiyun pm_runtime_disable(&pdev->dev);
80*4882a593Smuzhiyun
81*4882a593Smuzhiyun err0:
82*4882a593Smuzhiyun device_for_each_child(&pdev->dev, NULL, ocp2scp_remove_devices);
83*4882a593Smuzhiyun
84*4882a593Smuzhiyun return ret;
85*4882a593Smuzhiyun }
86*4882a593Smuzhiyun
omap_ocp2scp_remove(struct platform_device * pdev)87*4882a593Smuzhiyun static int omap_ocp2scp_remove(struct platform_device *pdev)
88*4882a593Smuzhiyun {
89*4882a593Smuzhiyun pm_runtime_disable(&pdev->dev);
90*4882a593Smuzhiyun device_for_each_child(&pdev->dev, NULL, ocp2scp_remove_devices);
91*4882a593Smuzhiyun
92*4882a593Smuzhiyun return 0;
93*4882a593Smuzhiyun }
94*4882a593Smuzhiyun
95*4882a593Smuzhiyun #ifdef CONFIG_OF
96*4882a593Smuzhiyun static const struct of_device_id omap_ocp2scp_id_table[] = {
97*4882a593Smuzhiyun { .compatible = "ti,omap-ocp2scp" },
98*4882a593Smuzhiyun { .compatible = "ti,am437x-ocp2scp" },
99*4882a593Smuzhiyun {}
100*4882a593Smuzhiyun };
101*4882a593Smuzhiyun MODULE_DEVICE_TABLE(of, omap_ocp2scp_id_table);
102*4882a593Smuzhiyun #endif
103*4882a593Smuzhiyun
104*4882a593Smuzhiyun static struct platform_driver omap_ocp2scp_driver = {
105*4882a593Smuzhiyun .probe = omap_ocp2scp_probe,
106*4882a593Smuzhiyun .remove = omap_ocp2scp_remove,
107*4882a593Smuzhiyun .driver = {
108*4882a593Smuzhiyun .name = "omap-ocp2scp",
109*4882a593Smuzhiyun .of_match_table = of_match_ptr(omap_ocp2scp_id_table),
110*4882a593Smuzhiyun },
111*4882a593Smuzhiyun };
112*4882a593Smuzhiyun
113*4882a593Smuzhiyun module_platform_driver(omap_ocp2scp_driver);
114*4882a593Smuzhiyun
115*4882a593Smuzhiyun MODULE_ALIAS("platform:omap-ocp2scp");
116*4882a593Smuzhiyun MODULE_AUTHOR("Texas Instruments Inc.");
117*4882a593Smuzhiyun MODULE_DESCRIPTION("OMAP OCP2SCP driver");
118*4882a593Smuzhiyun MODULE_LICENSE("GPL v2");
119