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1// SPDX-License-Identifier: GPL-2.02/*3 * Multiplexer driver for Analog Devices ADG792A/G Triple 4:1 mux4 *5 * Copyright (C) 2017 Axentia Technologies AB6 *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 23static 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 34static 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 else44 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 else51 cmd = ADG792A_MUX(controller, state);52 }53 54 return adg792a_write_cmd(i2c, cmd, 0);55}56 57static const struct mux_control_ops adg792a_ops = {58 .set = adg792a_set,59};60 61static 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(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 else122 dev_info(dev, "triple pole quadruple throw mux registered\n");123 124 return 0;125}126 127static const struct i2c_device_id adg792a_id[] = {128 { .name = "adg792a", },129 { .name = "adg792g", },130 { }131};132MODULE_DEVICE_TABLE(i2c, adg792a_id);133 134static const struct of_device_id adg792a_of_match[] = {135 { .compatible = "adi,adg792a", },136 { .compatible = "adi,adg792g", },137 { }138};139MODULE_DEVICE_TABLE(of, adg792a_of_match);140 141static 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};149module_i2c_driver(adg792a_driver);150 151MODULE_DESCRIPTION("Analog Devices ADG792A/G Triple 4:1 mux driver");152MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");153MODULE_LICENSE("GPL v2");154