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c942fddf | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
26a84b3e KVA |
2 | /* |
3 | * omap-ocp2scp.c - transform ocp interface protocol to scp protocol | |
4 | * | |
5 | * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com | |
26a84b3e | 6 | * Author: Kishon Vijay Abraham I <kishon@ti.com> |
26a84b3e KVA |
7 | */ |
8 | ||
cdf61240 | 9 | #include <linux/io.h> |
26a84b3e KVA |
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 | ||
cdf61240 KVA |
17 | #define OCP2SCP_TIMING 0x18 |
18 | #define SYNC2_MASK 0xf | |
19 | ||
26a84b3e KVA |
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 | ||
0fe763c5 | 29 | static int omap_ocp2scp_probe(struct platform_device *pdev) |
26a84b3e | 30 | { |
0133370f | 31 | int ret; |
cdf61240 KVA |
32 | u32 reg; |
33 | void __iomem *regs; | |
34 | struct resource *res; | |
0133370f | 35 | struct device_node *np = pdev->dev.of_node; |
26a84b3e KVA |
36 | |
37 | if (np) { | |
38 | ret = of_platform_populate(np, NULL, NULL, &pdev->dev); | |
39 | if (ret) { | |
0133370f KVA |
40 | dev_err(&pdev->dev, |
41 | "failed to add resources for ocp2scp child\n"); | |
26a84b3e KVA |
42 | goto err0; |
43 | } | |
44 | } | |
0133370f | 45 | |
26a84b3e | 46 | pm_runtime_enable(&pdev->dev); |
cdf61240 KVA |
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(np, "ti,am437x-ocp2scp")) { | |
61 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
62 | regs = devm_ioremap_resource(&pdev->dev, res); | |
672647af KVA |
63 | if (IS_ERR(regs)) { |
64 | ret = PTR_ERR(regs); | |
65 | goto err1; | |
66 | } | |
cdf61240 KVA |
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 | } | |
26a84b3e KVA |
75 | |
76 | return 0; | |
77 | ||
672647af KVA |
78 | err1: |
79 | pm_runtime_disable(&pdev->dev); | |
80 | ||
26a84b3e KVA |
81 | err0: |
82 | device_for_each_child(&pdev->dev, NULL, ocp2scp_remove_devices); | |
83 | ||
84 | return ret; | |
85 | } | |
86 | ||
0fe763c5 | 87 | static int omap_ocp2scp_remove(struct platform_device *pdev) |
26a84b3e KVA |
88 | { |
89 | pm_runtime_disable(&pdev->dev); | |
90 | device_for_each_child(&pdev->dev, NULL, 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" }, | |
cdf61240 | 98 | { .compatible = "ti,am437x-ocp2scp" }, |
26a84b3e KVA |
99 | {} |
100 | }; | |
46ca6811 | 101 | MODULE_DEVICE_TABLE(of, omap_ocp2scp_id_table); |
26a84b3e KVA |
102 | #endif |
103 | ||
104 | static struct platform_driver omap_ocp2scp_driver = { | |
105 | .probe = omap_ocp2scp_probe, | |
0fe763c5 | 106 | .remove = omap_ocp2scp_remove, |
26a84b3e KVA |
107 | .driver = { |
108 | .name = "omap-ocp2scp", | |
26a84b3e KVA |
109 | .of_match_table = of_match_ptr(omap_ocp2scp_id_table), |
110 | }, | |
111 | }; | |
112 | ||
113 | module_platform_driver(omap_ocp2scp_driver); | |
114 | ||
7ef71b70 | 115 | MODULE_ALIAS("platform:omap-ocp2scp"); |
26a84b3e KVA |
116 | MODULE_AUTHOR("Texas Instruments Inc."); |
117 | MODULE_DESCRIPTION("OMAP OCP2SCP driver"); | |
118 | MODULE_LICENSE("GPL v2"); |