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 #include <log.h>
  13 #include <malloc.h>
  14 #include <asm/global_data.h>
  15
  16 #include <asm-generic/gpio.h>
  17
  18 DECLARE_GLOBAL_DATA_PTR;
  19
  20 enum pca_type {
  21         PCA9543,
  22         PCA9544,
  23         PCA9546,
  24         PCA9547,
  25         PCA9548,
  26         PCA9646,
  27         PCA9847,
  28 };
  29
  30 struct chip_desc {
  31         u8 enable; /* Enable mask in ctl register (used for muxes only) */
  32         enum muxtype {
  33                 pca954x_ismux = 0,
  34                 pca954x_isswi,
  35         } muxtype;
  36         u32 width;
  37 };
  38
  39 struct pca954x_priv {
  40         u32 addr; /* I2C mux address */
  41         u32 width; /* I2C mux width - number of busses */
  42         struct gpio_desc gpio_mux_reset;
  43 };
  44
  45 static const struct chip_desc chips[] = {
  46         [PCA9543] = {
  47                 .muxtype = pca954x_isswi,
  48                 .width = 2,
  49         },
  50         [PCA9544] = {
  51                 .enable = 0x4,
  52                 .muxtype = pca954x_ismux,
  53                 .width = 4,
  54         },
  55         [PCA9546] = {
  56                 .muxtype = pca954x_isswi,
  57                 .width = 4,
  58         },
  59         [PCA9547] = {
  60                 .enable = 0x8,
  61                 .muxtype = pca954x_ismux,
  62                 .width = 8,
  63         },
  64         [PCA9548] = {
  65                 .muxtype = pca954x_isswi,
  66                 .width = 8,
  67         },
  68         [PCA9646] = {
  69                 .muxtype = pca954x_isswi,
  70                 .width = 4,
  71         },
  72         [PCA9847] = {
  73                 .enable = 0x8,
  74                 .muxtype = pca954x_ismux,
  75                 .width = 8,
  76         },
  77 };
  78
  79 static int pca954x_deselect(struct udevice *mux, struct udevice *bus,
  80                             uint channel)
  81 {
  82         struct pca954x_priv *priv = dev_get_priv(mux);
  83         uchar byte = 0;
  84
  85         return dm_i2c_write(mux, priv->addr, &byte, 1);
  86 }
  87
  88 static int pca954x_select(struct udevice *mux, struct udevice *bus,
  89                           uint channel)
  90 {
  91         struct pca954x_priv *priv = dev_get_priv(mux);
  92         const struct chip_desc *chip = &chips[dev_get_driver_data(mux)];
  93         uchar byte;
  94
  95         if (chip->muxtype == pca954x_ismux)
  96                 byte = channel | chip->enable;
  97         else
  98                 byte = 1 << channel;
  99
 100         return dm_i2c_write(mux, priv->addr, &byte, 1);
 101 }
 102
 103 static const struct i2c_mux_ops pca954x_ops = {
 104         .select = pca954x_select,
 105         .deselect = pca954x_deselect,
 106 };
 107
 108 static const struct udevice_id pca954x_ids[] = {
 109         { .compatible = "nxp,pca9543", .data = PCA9543 },
 110         { .compatible = "nxp,pca9544", .data = PCA9544 },
 111         { .compatible = "nxp,pca9546", .data = PCA9546 },
 112         { .compatible = "nxp,pca9547", .data = PCA9547 },
 113         { .compatible = "nxp,pca9548", .data = PCA9548 },
 114         { .compatible = "nxp,pca9646", .data = PCA9646 },
 115         { .compatible = "nxp,pca9847", .data = PCA9847 },
 116         { }
 117 };
 118
 119 static int pca954x_of_to_plat(struct udevice *dev)
 120 {
 121         struct pca954x_priv *priv = dev_get_priv(dev);
 122         const struct chip_desc *chip = &chips[dev_get_driver_data(dev)];
 123
 124         priv->addr = dev_read_u32_default(dev, "reg", 0);
 125         if (!priv->addr) {
 126                 debug("MUX not found\n");
 127                 return -ENODEV;
 128         }
 129         priv->width = chip->width;
 130
 131         if (!priv->width) {
 132                 debug("No I2C MUX width specified\n");
 133                 return -EINVAL;
 134         }
 135
 136         debug("Device %s at 0x%x with width %d\n",
 137               dev->name, priv->addr, priv->width);
 138
 139         return 0;
 140 }
 141
 142 static int pca954x_probe(struct udevice *dev)
 143 {
 144         if (CONFIG_IS_ENABLED(DM_GPIO)) {
 145                 struct pca954x_priv *priv = dev_get_priv(dev);
 146                 int err;
 147
 148                 err = gpio_request_by_name(dev, "reset-gpios", 0,
 149                                 &priv->gpio_mux_reset, GPIOD_IS_OUT);
 150
 151                 /* it's optional so only bail if we get a real error */
 152                 if (err && (err != -ENOENT))
 153                         return err;
 154
 155                 /* dm will take care of polarity */
 156                 if (dm_gpio_is_valid(&priv->gpio_mux_reset))
 157                         dm_gpio_set_value(&priv->gpio_mux_reset, 0);
 158         }
 159
 160         return 0;
 161 }
 162
 163 static int pca954x_remove(struct udevice *dev)
 164 {
 165         if (CONFIG_IS_ENABLED(DM_GPIO)) {
 166                 struct pca954x_priv *priv = dev_get_priv(dev);
 167
 168                 if (dm_gpio_is_valid(&priv->gpio_mux_reset))
 169                         dm_gpio_free(dev, &priv->gpio_mux_reset);
 170         }
 171
 172         return 0;
 173 }
 174
 175 U_BOOT_DRIVER(pca954x) = {
 176         .name = "pca954x",
 177         .id = UCLASS_I2C_MUX,
 178         .of_match = pca954x_ids,
 179         .probe = pca954x_probe,
 180         .remove = pca954x_remove,
 181         .ops = &pca954x_ops,
 182         .of_to_plat = pca954x_of_to_plat,
 183         .priv_auto      = sizeof(struct pca954x_priv),
 184 };