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

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