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(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 61 static int adg792a_probe(struct i2c_client *i2c, 62 const struct i2c_device_id *id) 63 { 64 struct device *dev = &i2c->dev; 65 struct mux_chip *mux_chip; 66 s32 idle_state[3]; 67 u32 cells; 68 int ret; 69 int i; 70 71 if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 72 return -ENODEV; 73 74 ret = device_property_read_u32(dev, "#mux-control-cells", &cells); 75 if (ret < 0) 76 return ret; 77 if (cells >= 2) 78 return -EINVAL; 79 80 mux_chip = devm_mux_chip_alloc(dev, cells ? 3 : 1, 0); 81 if (IS_ERR(mux_chip)) 82 return PTR_ERR(mux_chip); 83 84 mux_chip->ops = &adg792a_ops; 85 86 ret = adg792a_write_cmd(i2c, ADG792A_DISABLE_ALL, 1); 87 if (ret < 0) 88 return ret; 89 90 ret = device_property_read_u32_array(dev, "idle-state", 91 (u32 *)idle_state, 92 mux_chip->controllers); 93 if (ret < 0) { 94 idle_state[0] = MUX_IDLE_AS_IS; 95 idle_state[1] = MUX_IDLE_AS_IS; 96 idle_state[2] = MUX_IDLE_AS_IS; 97 } 98 99 for (i = 0; i < mux_chip->controllers; ++i) { 100 struct mux_control *mux = &mux_chip->mux[i]; 101 102 mux->states = 4; 103 104 switch (idle_state[i]) { 105 case MUX_IDLE_DISCONNECT: 106 case MUX_IDLE_AS_IS: 107 case 0 ... 4: 108 mux->idle_state = idle_state[i]; 109 break; 110 default: 111 dev_err(dev, "invalid idle-state %d\n", idle_state[i]); 112 return -EINVAL; 113 } 114 } 115 116 ret = devm_mux_chip_register(dev, mux_chip); 117 if (ret < 0) 118 return ret; 119 120 if (cells) 121 dev_info(dev, "3x single pole quadruple throw muxes registered\n"); 122 else 123 dev_info(dev, "triple pole quadruple throw mux registered\n"); 124 125 return 0; 126 } 127 128 static const struct i2c_device_id adg792a_id[] = { 129 { .name = "adg792a", }, 130 { .name = "adg792g", }, 131 { } 132 }; 133 MODULE_DEVICE_TABLE(i2c, adg792a_id); 134 135 static const struct of_device_id adg792a_of_match[] = { 136 { .compatible = "adi,adg792a", }, 137 { .compatible = "adi,adg792g", }, 138 { } 139 }; 140 MODULE_DEVICE_TABLE(of, adg792a_of_match); 141 142 static struct i2c_driver adg792a_driver = { 143 .driver = { 144 .name = "adg792a", 145 .of_match_table = of_match_ptr(adg792a_of_match), 146 }, 147 .probe = adg792a_probe, 148 .id_table = adg792a_id, 149 }; 150 module_i2c_driver(adg792a_driver); 151 152 MODULE_DESCRIPTION("Analog Devices ADG792A/G Triple 4:1 mux driver"); 153 MODULE_AUTHOR("Peter Rosin <peda@axentia.se>"); 154 MODULE_LICENSE("GPL v2"); 155