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35b8b92c JJH |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * MMIO register bitfield-controlled multiplexer driver | |
4 | * Based on the linux mmio multiplexer driver | |
5 | * | |
6 | * Copyright (C) 2017 Pengutronix, Philipp Zabel <kernel@pengutronix.de> | |
7 | * Copyright (C) 2019 Texas Instrument, Jean-jacques Hiblot <jjhiblot@ti.com> | |
8 | */ | |
9 | #include <common.h> | |
10 | #include <dm.h> | |
11 | #include <mux-internal.h> | |
12 | #include <regmap.h> | |
13 | #include <syscon.h> | |
14 | #include <dm/device.h> | |
15 | #include <dm/device_compat.h> | |
16 | #include <dm/read.h> | |
17 | #include <dm/devres.h> | |
18 | #include <dt-bindings/mux/mux.h> | |
19 | #include <linux/bitops.h> | |
20 | ||
21 | static int mux_mmio_set(struct mux_control *mux, int state) | |
22 | { | |
23 | struct regmap_field **fields = dev_get_priv(mux->dev); | |
24 | ||
25 | return regmap_field_write(fields[mux_control_get_index(mux)], state); | |
26 | } | |
27 | ||
28 | static const struct mux_control_ops mux_mmio_ops = { | |
29 | .set = mux_mmio_set, | |
30 | }; | |
31 | ||
32 | static const struct udevice_id mmio_mux_of_match[] = { | |
33 | { .compatible = "mmio-mux" }, | |
34 | { /* sentinel */ }, | |
35 | }; | |
36 | ||
37 | static int mmio_mux_probe(struct udevice *dev) | |
38 | { | |
39 | struct regmap_field **fields; | |
40 | struct mux_chip *mux_chip = dev_get_uclass_priv(dev); | |
41 | struct regmap *regmap; | |
42 | u32 *mux_reg_masks; | |
43 | u32 *idle_states; | |
44 | int num_fields; | |
45 | int ret; | |
46 | int i; | |
47 | ||
48 | regmap = syscon_node_to_regmap(dev_ofnode(dev->parent)); | |
49 | if (IS_ERR(regmap)) { | |
50 | ret = PTR_ERR(regmap); | |
51 | dev_err(dev, "failed to get regmap: %d\n", ret); | |
52 | return ret; | |
53 | } | |
54 | ||
55 | num_fields = dev_read_size(dev, "mux-reg-masks"); | |
56 | if (num_fields < 0) | |
57 | return log_msg_ret("mux-reg-masks missing", -EINVAL); | |
58 | ||
59 | num_fields /= sizeof(u32); | |
60 | if (num_fields == 0 || num_fields % 2) | |
61 | ret = -EINVAL; | |
62 | num_fields = num_fields / 2; | |
63 | ||
64 | ret = mux_alloc_controllers(dev, num_fields); | |
65 | if (ret < 0) | |
66 | return log_msg_ret("mux_alloc_controllers", ret); | |
67 | ||
68 | fields = devm_kmalloc(dev, num_fields * sizeof(*fields), __GFP_ZERO); | |
69 | if (!fields) | |
70 | return -ENOMEM; | |
71 | dev->priv = fields; | |
72 | ||
73 | mux_reg_masks = devm_kmalloc(dev, num_fields * 2 * sizeof(u32), | |
74 | __GFP_ZERO); | |
75 | if (!mux_reg_masks) | |
76 | return -ENOMEM; | |
77 | ||
78 | ret = dev_read_u32_array(dev, "mux-reg-masks", mux_reg_masks, | |
79 | num_fields * 2); | |
80 | if (ret < 0) | |
81 | return log_msg_ret("mux-reg-masks read", ret); | |
82 | ||
83 | idle_states = devm_kmalloc(dev, num_fields * sizeof(u32), __GFP_ZERO); | |
84 | if (!idle_states) | |
85 | return -ENOMEM; | |
86 | ||
87 | ret = dev_read_u32_array(dev, "idle-states", idle_states, num_fields); | |
88 | if (ret < 0) { | |
89 | log_err("idle-states"); | |
90 | devm_kfree(dev, idle_states); | |
91 | idle_states = NULL; | |
92 | } | |
93 | ||
94 | for (i = 0; i < num_fields; i++) { | |
95 | struct mux_control *mux = &mux_chip->mux[i]; | |
96 | struct reg_field field; | |
97 | u32 reg, mask; | |
98 | int bits; | |
99 | ||
100 | reg = mux_reg_masks[2 * i]; | |
101 | mask = mux_reg_masks[2 * i + 1]; | |
102 | ||
103 | field.reg = reg; | |
104 | field.msb = fls(mask) - 1; | |
105 | field.lsb = ffs(mask) - 1; | |
106 | ||
107 | if (mask != GENMASK(field.msb, field.lsb)) | |
108 | return log_msg_ret("invalid mask", -EINVAL); | |
109 | ||
110 | fields[i] = devm_regmap_field_alloc(dev, regmap, field); | |
111 | if (IS_ERR(fields[i])) { | |
112 | ret = PTR_ERR(fields[i]); | |
113 | return log_msg_ret("regmap_field_alloc", ret); | |
114 | } | |
115 | ||
116 | bits = 1 + field.msb - field.lsb; | |
117 | mux->states = 1 << bits; | |
118 | ||
119 | if (!idle_states) | |
120 | continue; | |
121 | ||
122 | if (idle_states[i] != MUX_IDLE_AS_IS && | |
123 | idle_states[i] >= mux->states) | |
124 | return log_msg_ret("idle-states range", -EINVAL); | |
125 | ||
126 | mux->idle_state = idle_states[i]; | |
127 | } | |
128 | ||
129 | devm_kfree(dev, mux_reg_masks); | |
130 | if (idle_states) | |
131 | devm_kfree(dev, idle_states); | |
132 | ||
133 | return 0; | |
134 | } | |
135 | ||
136 | U_BOOT_DRIVER(mmio_mux) = { | |
137 | .name = "mmio-mux", | |
138 | .id = UCLASS_MUX, | |
139 | .of_match = mmio_mux_of_match, | |
140 | .probe = mmio_mux_probe, | |
141 | .ops = &mux_mmio_ops, | |
142 | }; |