LXR linux/drivers/mux/adg792a.c

   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
  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                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
  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        else
 122                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_new      = 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