LXR uboot/drivers/i2c/muxes/pca954x.c

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Copyright (C) 2015 - 2016 Xilinx, Inc.
   4 * Copyright (C) 2017 National Instruments Corp
   5 * Written by Michal Simek
   6 */
   7
   8#include <common.h>
   9#include <dm.h>
  10#include <errno.h>
  11#include <i2c.h>
  12
  13#include <asm-generic/gpio.h>
  14
  15DECLARE_GLOBAL_DATA_PTR;
  16
  17enum pca_type {
  18        PCA9543,
  19        PCA9544,
  20        PCA9547,
  21        PCA9548,
  22        PCA9646
  23};
  24
  25struct chip_desc {
  26        u8 enable; /* Enable mask in ctl register (used for muxes only) */
  27        enum muxtype {
  28                pca954x_ismux = 0,
  29                pca954x_isswi,
  30        } muxtype;
  31        u32 width;
  32};
  33
  34struct pca954x_priv {
  35        u32 addr; /* I2C mux address */
  36        u32 width; /* I2C mux width - number of busses */
  37        struct gpio_desc gpio_mux_reset;
  38};
  39
  40static const struct chip_desc chips[] = {
  41        [PCA9543] = {
  42                .muxtype = pca954x_isswi,
  43                .width = 2,
  44        },
  45        [PCA9544] = {
  46                .enable = 0x4,
  47                .muxtype = pca954x_ismux,
  48                .width = 4,
  49        },
  50        [PCA9547] = {
  51                .enable = 0x8,
  52                .muxtype = pca954x_ismux,
  53                .width = 8,
  54        },
  55        [PCA9548] = {
  56                .muxtype = pca954x_isswi,
  57                .width = 8,
  58        },
  59        [PCA9646] = {
  60                .muxtype = pca954x_isswi,
  61                .width = 4,
  62        },
  63};
  64
  65static int pca954x_deselect(struct udevice *mux, struct udevice *bus,
  66                            uint channel)
  67{
  68        struct pca954x_priv *priv = dev_get_priv(mux);
  69        uchar byte = 0;
  70
  71        return dm_i2c_write(mux, priv->addr, &byte, 1);
  72}
  73
  74static int pca954x_select(struct udevice *mux, struct udevice *bus,
  75                          uint channel)
  76{
  77        struct pca954x_priv *priv = dev_get_priv(mux);
  78        const struct chip_desc *chip = &chips[dev_get_driver_data(mux)];
  79        uchar byte;
  80
  81        if (chip->muxtype == pca954x_ismux)
  82                byte = channel | chip->enable;
  83        else
  84                byte = 1 << channel;
  85
  86        return dm_i2c_write(mux, priv->addr, &byte, 1);
  87}
  88
  89static const struct i2c_mux_ops pca954x_ops = {
  90        .select = pca954x_select,
  91        .deselect = pca954x_deselect,
  92};
  93
  94static const struct udevice_id pca954x_ids[] = {
  95        { .compatible = "nxp,pca9543", .data = PCA9543 },
  96        { .compatible = "nxp,pca9544", .data = PCA9544 },
  97        { .compatible = "nxp,pca9547", .data = PCA9547 },
  98        { .compatible = "nxp,pca9548", .data = PCA9548 },
  99        { .compatible = "nxp,pca9646", .data = PCA9646 },
 100        { }
 101};
 102
 103static int pca954x_ofdata_to_platdata(struct udevice *dev)
 104{
 105        struct pca954x_priv *priv = dev_get_priv(dev);
 106        const struct chip_desc *chip = &chips[dev_get_driver_data(dev)];
 107
 108        priv->addr = dev_read_u32_default(dev, "reg", 0);
 109        if (!priv->addr) {
 110                debug("MUX not found\n");
 111                return -ENODEV;
 112        }
 113        priv->width = chip->width;
 114
 115        if (!priv->width) {
 116                debug("No I2C MUX width specified\n");
 117                return -EINVAL;
 118        }
 119
 120        debug("Device %s at 0x%x with width %d\n",
 121              dev->name, priv->addr, priv->width);
 122
 123        return 0;
 124}
 125
 126static int pca954x_probe(struct udevice *dev)
 127{
 128        if (IS_ENABLED(CONFIG_DM_GPIO)) {
 129                struct pca954x_priv *priv = dev_get_priv(dev);
 130                int err;
 131
 132                err = gpio_request_by_name(dev, "reset-gpios", 0,
 133                                &priv->gpio_mux_reset, GPIOD_IS_OUT);
 134
 135                /* it's optional so only bail if we get a real error */
 136                if (err && (err != -ENOENT))
 137                        return err;
 138
 139                /* dm will take care of polarity */
 140                if (dm_gpio_is_valid(&priv->gpio_mux_reset))
 141                        dm_gpio_set_value(&priv->gpio_mux_reset, 0);
 142        }
 143
 144        return 0;
 145}
 146
 147static int pca954x_remove(struct udevice *dev)
 148{
 149        if (IS_ENABLED(CONFIG_DM_GPIO)) {
 150                struct pca954x_priv *priv = dev_get_priv(dev);
 151
 152                if (dm_gpio_is_valid(&priv->gpio_mux_reset))
 153                        dm_gpio_free(dev, &priv->gpio_mux_reset);
 154        }
 155
 156        return 0;
 157}
 158
 159U_BOOT_DRIVER(pca954x) = {
 160        .name = "pca954x",
 161        .id = UCLASS_I2C_MUX,
 162        .of_match = pca954x_ids,
 163        .probe = pca954x_probe,
 164        .remove = pca954x_remove,
 165        .ops = &pca954x_ops,
 166        .ofdata_to_platdata = pca954x_ofdata_to_platdata,
 167        .priv_auto_alloc_size = sizeof(struct pca954x_priv),
 168};
 169