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83d290c5 | 1 | // SPDX-License-Identifier: GPL-2.0+ |
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2 | /* |
3 | * I2C multiplexer using GPIO API | |
4 | * | |
5 | * Copyright 2017 NXP | |
6 | * | |
7 | * Peng Fan <peng.fan@nxp.com> | |
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8 | */ |
9 | ||
401d1c4f | 10 | #include <asm/global_data.h> |
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11 | #include <asm/io.h> |
12 | #include <asm-generic/gpio.h> | |
13 | #include <common.h> | |
14 | #include <dm.h> | |
336d4615 | 15 | #include <dm/device_compat.h> |
61b29b82 | 16 | #include <dm/devres.h> |
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17 | #include <dm/pinctrl.h> |
18 | #include <fdtdec.h> | |
19 | #include <i2c.h> | |
20 | #include <linux/errno.h> | |
4d72caa5 | 21 | #include <linux/libfdt.h> |
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22 | |
23 | DECLARE_GLOBAL_DATA_PTR; | |
24 | ||
25 | /** | |
26 | * struct i2c_mux_gpio_priv - private data for i2c mux gpio | |
27 | * | |
28 | * @values: the reg value of each child node | |
29 | * @n_values: num of regs | |
30 | * @gpios: the mux-gpios array | |
31 | * @n_gpios: num of gpios in mux-gpios | |
32 | * @idle: the value of idle-state | |
33 | */ | |
34 | struct i2c_mux_gpio_priv { | |
35 | u32 *values; | |
36 | int n_values; | |
37 | struct gpio_desc *gpios; | |
38 | int n_gpios; | |
39 | u32 idle; | |
40 | }; | |
41 | ||
42 | ||
43 | static int i2c_mux_gpio_select(struct udevice *dev, struct udevice *bus, | |
44 | uint channel) | |
45 | { | |
46 | struct i2c_mux_gpio_priv *priv = dev_get_priv(dev); | |
47 | int i, ret; | |
48 | ||
49 | for (i = 0; i < priv->n_gpios; i++) { | |
50 | ret = dm_gpio_set_value(&priv->gpios[i], (channel >> i) & 1); | |
51 | if (ret) | |
52 | return ret; | |
53 | } | |
54 | ||
55 | return 0; | |
56 | } | |
57 | ||
58 | static int i2c_mux_gpio_deselect(struct udevice *dev, struct udevice *bus, | |
59 | uint channel) | |
60 | { | |
61 | struct i2c_mux_gpio_priv *priv = dev_get_priv(dev); | |
62 | int i, ret; | |
63 | ||
64 | for (i = 0; i < priv->n_gpios; i++) { | |
65 | ret = dm_gpio_set_value(&priv->gpios[i], (priv->idle >> i) & 1); | |
66 | if (ret) | |
67 | return ret; | |
68 | } | |
69 | ||
70 | return 0; | |
71 | } | |
72 | ||
73 | static int i2c_mux_gpio_probe(struct udevice *dev) | |
74 | { | |
75 | const void *fdt = gd->fdt_blob; | |
76 | int node = dev_of_offset(dev); | |
77 | struct i2c_mux_gpio_priv *mux = dev_get_priv(dev); | |
78 | struct gpio_desc *gpios; | |
79 | u32 *values; | |
80 | int i = 0, subnode, ret; | |
81 | ||
82 | mux->n_values = fdtdec_get_child_count(fdt, node); | |
83 | values = devm_kzalloc(dev, sizeof(*mux->values) * mux->n_values, | |
84 | GFP_KERNEL); | |
85 | if (!values) { | |
86 | dev_err(dev, "Cannot alloc values array"); | |
87 | return -ENOMEM; | |
88 | } | |
89 | ||
90 | fdt_for_each_subnode(subnode, fdt, node) { | |
91 | *(values + i) = fdtdec_get_uint(fdt, subnode, "reg", -1); | |
92 | i++; | |
93 | } | |
94 | ||
95 | mux->values = values; | |
96 | ||
97 | mux->idle = fdtdec_get_uint(fdt, node, "idle-state", -1); | |
98 | ||
99 | mux->n_gpios = gpio_get_list_count(dev, "mux-gpios"); | |
100 | if (mux->n_gpios < 0) { | |
101 | dev_err(dev, "Missing mux-gpios property\n"); | |
102 | return -EINVAL; | |
103 | } | |
104 | ||
105 | gpios = devm_kzalloc(dev, sizeof(struct gpio_desc) * mux->n_gpios, | |
106 | GFP_KERNEL); | |
107 | if (!gpios) { | |
108 | dev_err(dev, "Cannot allocate gpios array\n"); | |
109 | return -ENOMEM; | |
110 | } | |
111 | ||
112 | ret = gpio_request_list_by_name(dev, "mux-gpios", gpios, mux->n_gpios, | |
42cc3125 | 113 | GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE); |
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114 | if (ret <= 0) { |
115 | dev_err(dev, "Failed to request mux-gpios\n"); | |
116 | return ret; | |
117 | } | |
118 | ||
119 | mux->gpios = gpios; | |
120 | ||
121 | return 0; | |
122 | } | |
123 | ||
124 | static const struct i2c_mux_ops i2c_mux_gpio_ops = { | |
125 | .select = i2c_mux_gpio_select, | |
126 | .deselect = i2c_mux_gpio_deselect, | |
127 | }; | |
128 | ||
129 | static const struct udevice_id i2c_mux_gpio_ids[] = { | |
130 | { .compatible = "i2c-mux-gpio", }, | |
131 | {} | |
132 | }; | |
133 | ||
134 | U_BOOT_DRIVER(i2c_mux_gpio) = { | |
135 | .name = "i2c_mux_gpio", | |
136 | .id = UCLASS_I2C_MUX, | |
137 | .of_match = i2c_mux_gpio_ids, | |
138 | .ops = &i2c_mux_gpio_ops, | |
139 | .probe = i2c_mux_gpio_probe, | |
41575d8e | 140 | .priv_auto = sizeof(struct i2c_mux_gpio_priv), |
a430556e | 141 | }; |