1 | // SPDX-License-Identifier: GPL-2.0 |
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> |
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(client: i2c, command: cmd, value: 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, reset: 0); |
55 | } |
56 | |
57 | static const struct mux_control_ops adg792a_ops = { |
58 | .set = adg792a_set, |
59 | }; |
60 | |
61 | static int adg792a_probe(struct i2c_client *i2c) |
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(adap: i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA)) |
71 | return -ENODEV; |
72 | |
73 | ret = device_property_read_u32(dev, propname: "#mux-control-cells" , val: &cells); |
74 | if (ret < 0) |
75 | return ret; |
76 | if (cells >= 2) |
77 | return -EINVAL; |
78 | |
79 | mux_chip = devm_mux_chip_alloc(dev, controllers: cells ? 3 : 1, sizeof_priv: 0); |
80 | if (IS_ERR(ptr: mux_chip)) |
81 | return PTR_ERR(ptr: mux_chip); |
82 | |
83 | mux_chip->ops = &adg792a_ops; |
84 | |
85 | ret = adg792a_write_cmd(i2c, ADG792A_DISABLE_ALL, reset: 1); |
86 | if (ret < 0) |
87 | return ret; |
88 | |
89 | ret = device_property_read_u32_array(dev, propname: "idle-state" , |
90 | val: (u32 *)idle_state, |
91 | nval: 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 | }, |
146 | .probe = adg792a_probe, |
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" ); |
154 | |