1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * omap-ocp2scp.c - transform ocp interface protocol to scp protocol |
4 | * |
5 | * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com |
6 | * 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 0x18 |
18 | #define SYNC2_MASK 0xf |
19 | |
20 | static 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 | |
29 | static 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(root: np, NULL, NULL, parent: &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(dev: &pdev->dev); |
47 | /* |
48 | * As per AM572x TRM: http://www.ti.com/lit/ug/spruhz6/spruhz6.pdf |
49 | * 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.pdf |
51 | * 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.pdf |
53 | * under section 23.12.6.2.2, Table 23-1213 OCP2SCP TIMING Caution; |
54 | * As per OMAP543x TRM http://www.ti.com/lit/pdf/swpu249 |
55 | * 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 value |
58 | * of SYNC2 parameter in OCP2SCP. Suggested reset value is 0x6 or more. |
59 | */ |
60 | if (!of_device_is_compatible(device: np, "ti,am437x-ocp2scp" )) { |
61 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
62 | regs = devm_ioremap_resource(dev: &pdev->dev, res); |
63 | if (IS_ERR(ptr: regs)) { |
64 | ret = PTR_ERR(ptr: regs); |
65 | goto err1; |
66 | } |
67 | |
68 | pm_runtime_get_sync(dev: &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(dev: &pdev->dev); |
74 | } |
75 | |
76 | return 0; |
77 | |
78 | err1: |
79 | pm_runtime_disable(dev: &pdev->dev); |
80 | |
81 | err0: |
82 | device_for_each_child(dev: &pdev->dev, NULL, fn: ocp2scp_remove_devices); |
83 | |
84 | return ret; |
85 | } |
86 | |
87 | static int omap_ocp2scp_remove(struct platform_device *pdev) |
88 | { |
89 | pm_runtime_disable(dev: &pdev->dev); |
90 | device_for_each_child(dev: &pdev->dev, NULL, fn: ocp2scp_remove_devices); |
91 | |
92 | return 0; |
93 | } |
94 | |
95 | #ifdef CONFIG_OF |
96 | static const struct of_device_id omap_ocp2scp_id_table[] = { |
97 | { .compatible = "ti,omap-ocp2scp" }, |
98 | { .compatible = "ti,am437x-ocp2scp" }, |
99 | {} |
100 | }; |
101 | MODULE_DEVICE_TABLE(of, omap_ocp2scp_id_table); |
102 | #endif |
103 | |
104 | static struct platform_driver omap_ocp2scp_driver = { |
105 | .probe = omap_ocp2scp_probe, |
106 | .remove = omap_ocp2scp_remove, |
107 | .driver = { |
108 | .name = "omap-ocp2scp" , |
109 | .of_match_table = of_match_ptr(omap_ocp2scp_id_table), |
110 | }, |
111 | }; |
112 | |
113 | module_platform_driver(omap_ocp2scp_driver); |
114 | |
115 | MODULE_ALIAS("platform:omap-ocp2scp" ); |
116 | MODULE_AUTHOR("Texas Instruments Inc." ); |
117 | MODULE_DESCRIPTION("OMAP OCP2SCP driver" ); |
118 | MODULE_LICENSE("GPL v2" ); |
119 | |