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0edff03d | 1 | // SPDX-License-Identifier: GPL-2.0 |
afda08c4 PR |
2 | /* |
3 | * Multiplexer driver for Analog Devices ADG792A/G Triple 4:1 mux | |
4 | * | |
5 | * Copyright (C) 2017 Axentia Technologies AB | |
6 | * | |
7 | * Author: Peter Rosin <peda@axentia.se> | |
afda08c4 PR |
8 | */ |
9 | ||
10 | #include <linux/err.h> | |
11 | #include <linux/i2c.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/mux/driver.h> | |
14 | #include <linux/property.h> | |
15 | ||
16 | #define ADG792A_LDSW BIT(0) | |
17 | #define ADG792A_RESETB BIT(1) | |
18 | #define ADG792A_DISABLE(mux) (0x50 | (mux)) | |
19 | #define ADG792A_DISABLE_ALL (0x5f) | |
20 | #define ADG792A_MUX(mux, state) (0xc0 | (((mux) + 1) << 2) | (state)) | |
21 | #define ADG792A_MUX_ALL(state) (0xc0 | (state)) | |
22 | ||
23 | static int adg792a_write_cmd(struct i2c_client *i2c, u8 cmd, int reset) | |
24 | { | |
25 | u8 data = ADG792A_RESETB | ADG792A_LDSW; | |
26 | ||
27 | /* ADG792A_RESETB is active low, the chip resets when it is zero. */ | |
28 | if (reset) | |
29 | data &= ~ADG792A_RESETB; | |
30 | ||
31 | return i2c_smbus_write_byte_data(i2c, cmd, data); | |
32 | } | |
33 | ||
34 | static int adg792a_set(struct mux_control *mux, int state) | |
35 | { | |
36 | struct i2c_client *i2c = to_i2c_client(mux->chip->dev.parent); | |
37 | u8 cmd; | |
38 | ||
39 | if (mux->chip->controllers == 1) { | |
40 | /* parallel mux controller operation */ | |
41 | if (state == MUX_IDLE_DISCONNECT) | |
42 | cmd = ADG792A_DISABLE_ALL; | |
43 | else | |
44 | cmd = ADG792A_MUX_ALL(state); | |
45 | } else { | |
46 | unsigned int controller = mux_control_get_index(mux); | |
47 | ||
48 | if (state == MUX_IDLE_DISCONNECT) | |
49 | cmd = ADG792A_DISABLE(controller); | |
50 | else | |
51 | cmd = ADG792A_MUX(controller, state); | |
52 | } | |
53 | ||
54 | return adg792a_write_cmd(i2c, cmd, 0); | |
55 | } | |
56 | ||
57 | static const struct mux_control_ops adg792a_ops = { | |
58 | .set = adg792a_set, | |
59 | }; | |
60 | ||
2c363576 | 61 | static int adg792a_probe(struct i2c_client *i2c) |
afda08c4 PR |
62 | { |
63 | struct device *dev = &i2c->dev; | |
64 | struct mux_chip *mux_chip; | |
65 | s32 idle_state[3]; | |
66 | u32 cells; | |
67 | int ret; | |
68 | int i; | |
69 | ||
70 | if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA)) | |
71 | return -ENODEV; | |
72 | ||
73 | ret = device_property_read_u32(dev, "#mux-control-cells", &cells); | |
74 | if (ret < 0) | |
75 | return ret; | |
76 | if (cells >= 2) | |
77 | return -EINVAL; | |
78 | ||
79 | mux_chip = devm_mux_chip_alloc(dev, cells ? 3 : 1, 0); | |
80 | if (IS_ERR(mux_chip)) | |
81 | return PTR_ERR(mux_chip); | |
82 | ||
83 | mux_chip->ops = &adg792a_ops; | |
84 | ||
85 | ret = adg792a_write_cmd(i2c, ADG792A_DISABLE_ALL, 1); | |
86 | if (ret < 0) | |
87 | return ret; | |
88 | ||
89 | ret = device_property_read_u32_array(dev, "idle-state", | |
90 | (u32 *)idle_state, | |
91 | mux_chip->controllers); | |
92 | if (ret < 0) { | |
93 | idle_state[0] = MUX_IDLE_AS_IS; | |
94 | idle_state[1] = MUX_IDLE_AS_IS; | |
95 | idle_state[2] = MUX_IDLE_AS_IS; | |
96 | } | |
97 | ||
98 | for (i = 0; i < mux_chip->controllers; ++i) { | |
99 | struct mux_control *mux = &mux_chip->mux[i]; | |
100 | ||
101 | mux->states = 4; | |
102 | ||
103 | switch (idle_state[i]) { | |
104 | case MUX_IDLE_DISCONNECT: | |
105 | case MUX_IDLE_AS_IS: | |
106 | case 0 ... 4: | |
107 | mux->idle_state = idle_state[i]; | |
108 | break; | |
109 | default: | |
110 | dev_err(dev, "invalid idle-state %d\n", idle_state[i]); | |
111 | return -EINVAL; | |
112 | } | |
113 | } | |
114 | ||
115 | ret = devm_mux_chip_register(dev, mux_chip); | |
116 | if (ret < 0) | |
117 | return ret; | |
118 | ||
119 | if (cells) | |
120 | dev_info(dev, "3x single pole quadruple throw muxes registered\n"); | |
121 | else | |
122 | dev_info(dev, "triple pole quadruple throw mux registered\n"); | |
123 | ||
124 | return 0; | |
125 | } | |
126 | ||
127 | static const struct i2c_device_id adg792a_id[] = { | |
128 | { .name = "adg792a", }, | |
129 | { .name = "adg792g", }, | |
130 | { } | |
131 | }; | |
132 | MODULE_DEVICE_TABLE(i2c, adg792a_id); | |
133 | ||
134 | static const struct of_device_id adg792a_of_match[] = { | |
135 | { .compatible = "adi,adg792a", }, | |
136 | { .compatible = "adi,adg792g", }, | |
137 | { } | |
138 | }; | |
139 | MODULE_DEVICE_TABLE(of, adg792a_of_match); | |
140 | ||
141 | static struct i2c_driver adg792a_driver = { | |
142 | .driver = { | |
143 | .name = "adg792a", | |
144 | .of_match_table = of_match_ptr(adg792a_of_match), | |
145 | }, | |
2c363576 | 146 | .probe_new = adg792a_probe, |
afda08c4 PR |
147 | .id_table = adg792a_id, |
148 | }; | |
149 | module_i2c_driver(adg792a_driver); | |
150 | ||
151 | MODULE_DESCRIPTION("Analog Devices ADG792A/G Triple 4:1 mux driver"); | |
152 | MODULE_AUTHOR("Peter Rosin <peda@axentia.se>"); | |
153 | MODULE_LICENSE("GPL v2"); |