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