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1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* | |
3 | * ARM Integrator Logical Module bus driver | |
4 | * Copyright (C) 2020 Linaro Ltd. | |
5 | * Author: Linus Walleij <linus.walleij@linaro.org> | |
6 | * | |
7 | * See the device tree bindings for this block for more details on the | |
8 | * hardware. | |
9 | */ | |
10 | ||
11 | #include <linux/module.h> | |
12 | #include <linux/err.h> | |
13 | #include <linux/io.h> | |
14 | #include <linux/of.h> | |
15 | #include <linux/of_address.h> | |
16 | #include <linux/of_platform.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/platform_device.h> | |
20 | #include <linux/bitops.h> | |
21 | #include <linux/mfd/syscon.h> | |
22 | #include <linux/regmap.h> | |
23 | ||
24 | /* All information about the connected logic modules are in here */ | |
25 | #define INTEGRATOR_SC_DEC_OFFSET 0x10 | |
26 | ||
27 | /* Base address for the expansion modules */ | |
28 | #define INTEGRATOR_AP_EXP_BASE 0xc0000000 | |
29 | #define INTEGRATOR_AP_EXP_STRIDE 0x10000000 | |
30 | ||
31 | static int integrator_lm_populate(int num, struct device *dev) | |
32 | { | |
33 | struct device_node *np = dev->of_node; | |
34 | struct device_node *child; | |
35 | u32 base; | |
36 | int ret; | |
37 | ||
38 | base = INTEGRATOR_AP_EXP_BASE + (num * INTEGRATOR_AP_EXP_STRIDE); | |
39 | ||
40 | /* Walk over the child nodes and see what chipselects we use */ | |
41 | for_each_available_child_of_node(np, child) { | |
42 | struct resource res; | |
43 | ||
44 | ret = of_address_to_resource(child, 0, &res); | |
45 | if (ret) { | |
46 | dev_info(dev, "no valid address on child\n"); | |
47 | continue; | |
48 | } | |
49 | ||
50 | /* First populate the syscon then any devices */ | |
51 | if (res.start == base) { | |
52 | dev_info(dev, "populate module @0x%08x from DT\n", | |
53 | base); | |
54 | ret = of_platform_default_populate(child, NULL, dev); | |
55 | if (ret) { | |
56 | dev_err(dev, "failed to populate module\n"); | |
1740e673 | 57 | of_node_put(child); |
ccea5e8a LW |
58 | return ret; |
59 | } | |
60 | } | |
61 | } | |
62 | ||
63 | return 0; | |
64 | } | |
65 | ||
66 | static const struct of_device_id integrator_ap_syscon_match[] = { | |
67 | { .compatible = "arm,integrator-ap-syscon"}, | |
68 | { }, | |
69 | }; | |
70 | ||
71 | static int integrator_ap_lm_probe(struct platform_device *pdev) | |
72 | { | |
73 | struct device *dev = &pdev->dev; | |
74 | struct device_node *syscon; | |
75 | static struct regmap *map; | |
76 | u32 val; | |
77 | int ret; | |
78 | int i; | |
79 | ||
80 | /* Look up the system controller */ | |
81 | syscon = of_find_matching_node(NULL, integrator_ap_syscon_match); | |
97a2f40e | 82 | if (!syscon) { |
ccea5e8a LW |
83 | dev_err(dev, |
84 | "could not find Integrator/AP system controller\n"); | |
97a2f40e | 85 | return -ENODEV; |
ccea5e8a LW |
86 | } |
87 | map = syscon_node_to_regmap(syscon); | |
88 | if (IS_ERR(map)) { | |
89 | dev_err(dev, | |
90 | "could not find Integrator/AP system controller\n"); | |
91 | return PTR_ERR(map); | |
92 | } | |
93 | ||
94 | ret = regmap_read(map, INTEGRATOR_SC_DEC_OFFSET, &val); | |
95 | if (ret) { | |
96 | dev_err(dev, "could not read from Integrator/AP syscon\n"); | |
97 | return ret; | |
98 | } | |
99 | ||
100 | /* Loop over the connected modules */ | |
101 | for (i = 0; i < 4; i++) { | |
102 | if (!(val & BIT(4 + i))) | |
103 | continue; | |
104 | ||
105 | dev_info(dev, "detected module in slot %d\n", i); | |
106 | ret = integrator_lm_populate(i, dev); | |
107 | if (ret) | |
108 | return ret; | |
109 | } | |
110 | ||
111 | return 0; | |
112 | } | |
113 | ||
114 | static const struct of_device_id integrator_ap_lm_match[] = { | |
115 | { .compatible = "arm,integrator-ap-lm"}, | |
116 | { }, | |
117 | }; | |
118 | ||
119 | static struct platform_driver integrator_ap_lm_driver = { | |
120 | .probe = integrator_ap_lm_probe, | |
121 | .driver = { | |
122 | .name = "integratorap-lm", | |
123 | .of_match_table = integrator_ap_lm_match, | |
124 | }, | |
125 | }; | |
126 | module_platform_driver(integrator_ap_lm_driver); | |
127 | MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>"); | |
128 | MODULE_DESCRIPTION("Integrator AP Logical Module driver"); | |
129 | MODULE_LICENSE("GPL v2"); |