git.sur5r.net Git - u-boot/blob - drivers/i2c/muxes/pca954x.c

   1 /*
   2  * Copyright (C) 2015 - 2016 Xilinx, Inc.
   3  * Written by Michal Simek
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <dm.h>
  10 #include <errno.h>
  11 #include <i2c.h>
  12 #include <asm/gpio.h>
  13
  14 DECLARE_GLOBAL_DATA_PTR;
  15
  16 enum pca_type {
  17         PCA9544,
  18         PCA9547,
  19         PCA9548
  20 };
  21
  22 struct chip_desc {
  23         u8 enable;
  24         enum muxtype {
  25                 pca954x_ismux = 0,
  26                 pca954x_isswi,
  27         } muxtype;
  28 };
  29
  30 struct pca954x_priv {
  31         u32 addr; /* I2C mux address */
  32         u32 width; /* I2C mux width - number of busses */
  33 };
  34
  35 static const struct chip_desc chips[] = {
  36         [PCA9544] = {
  37                 .enable = 0x4,
  38                 .muxtype = pca954x_ismux,
  39         },
  40         [PCA9547] = {
  41                 .enable = 0x8,
  42                 .muxtype = pca954x_ismux,
  43         },
  44         [PCA9548] = {
  45                 .enable = 0x8,
  46                 .muxtype = pca954x_isswi,
  47         },
  48 };
  49
  50 static int pca954x_deselect(struct udevice *mux, struct udevice *bus,
  51                             uint channel)
  52 {
  53         struct pca954x_priv *priv = dev_get_priv(mux);
  54         uchar byte = 0;
  55
  56         return dm_i2c_write(mux, priv->addr, &byte, 1);
  57 }
  58
  59 static int pca954x_select(struct udevice *mux, struct udevice *bus,
  60                           uint channel)
  61 {
  62         struct pca954x_priv *priv = dev_get_priv(mux);
  63         const struct chip_desc *chip = &chips[dev_get_driver_data(mux)];
  64         uchar byte;
  65
  66         if (chip->muxtype == pca954x_ismux)
  67                 byte = channel | chip->enable;
  68         else
  69                 byte = 1 << channel;
  70
  71         return dm_i2c_write(mux, priv->addr, &byte, 1);
  72 }
  73
  74 static const struct i2c_mux_ops pca954x_ops = {
  75         .select = pca954x_select,
  76         .deselect = pca954x_deselect,
  77 };
  78
  79 static const struct udevice_id pca954x_ids[] = {
  80         { .compatible = "nxp,pca9544", .data = PCA9544 },
  81         { .compatible = "nxp,pca9547", .data = PCA9547 },
  82         { .compatible = "nxp,pca9548", .data = PCA9548 },
  83         { }
  84 };
  85
  86 static int pca954x_ofdata_to_platdata(struct udevice *dev)
  87 {
  88         struct pca954x_priv *priv = dev_get_priv(dev);
  89
  90         priv->addr = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev), "reg", 0);
  91         if (!priv->addr) {
  92                 debug("MUX not found\n");
  93                 return -ENODEV;
  94         }
  95         priv->width = dev_get_driver_data(dev);
  96
  97         if (!priv->width) {
  98                 debug("No I2C MUX width specified\n");
  99                 return -EINVAL;
 100         }
 101
 102         debug("Device %s at 0x%x with width %d\n",
 103               dev->name, priv->addr, priv->width);
 104
 105         return 0;
 106 }
 107
 108 U_BOOT_DRIVER(pca954x) = {
 109         .name = "pca954x",
 110         .id = UCLASS_I2C_MUX,
 111         .of_match = pca954x_ids,
 112         .ops = &pca954x_ops,
 113         .ofdata_to_platdata = pca954x_ofdata_to_platdata,
 114         .priv_auto_alloc_size = sizeof(struct pca954x_priv),
 115 };