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 };
  31
  32 struct pca954x_priv {
  33         u32 addr; /* I2C mux address */
  34         u32 width; /* I2C mux width - number of busses */
  35         struct gpio_desc gpio_mux_reset;
  36 };
  37
  38 static const struct chip_desc chips[] = {
  39         [PCA9544] = {
  40                 .enable = 0x4,
  41                 .muxtype = pca954x_ismux,
  42         },
  43         [PCA9547] = {
  44                 .enable = 0x8,
  45                 .muxtype = pca954x_ismux,
  46         },
  47         [PCA9548] = {
  48                 .enable = 0x8,
  49                 .muxtype = pca954x_isswi,
  50         },
  51 };
  52
  53 static int pca954x_deselect(struct udevice *mux, struct udevice *bus,
  54                             uint channel)
  55 {
  56         struct pca954x_priv *priv = dev_get_priv(mux);
  57         uchar byte = 0;
  58
  59         return dm_i2c_write(mux, priv->addr, &byte, 1);
  60 }
  61
  62 static int pca954x_select(struct udevice *mux, struct udevice *bus,
  63                           uint channel)
  64 {
  65         struct pca954x_priv *priv = dev_get_priv(mux);
  66         const struct chip_desc *chip = &chips[dev_get_driver_data(mux)];
  67         uchar byte;
  68
  69         if (chip->muxtype == pca954x_ismux)
  70                 byte = channel | chip->enable;
  71         else
  72                 byte = 1 << channel;
  73
  74         return dm_i2c_write(mux, priv->addr, &byte, 1);
  75 }
  76
  77 static const struct i2c_mux_ops pca954x_ops = {
  78         .select = pca954x_select,
  79         .deselect = pca954x_deselect,
  80 };
  81
  82 static const struct udevice_id pca954x_ids[] = {
  83         { .compatible = "nxp,pca9544", .data = PCA9544 },
  84         { .compatible = "nxp,pca9547", .data = PCA9547 },
  85         { .compatible = "nxp,pca9548", .data = PCA9548 },
  86         { }
  87 };
  88
  89 static int pca954x_ofdata_to_platdata(struct udevice *dev)
  90 {
  91         struct pca954x_priv *priv = dev_get_priv(dev);
  92
  93         priv->addr = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev), "reg", 0);
  94         if (!priv->addr) {
  95                 debug("MUX not found\n");
  96                 return -ENODEV;
  97         }
  98         priv->width = dev_get_driver_data(dev);
  99
 100         if (!priv->width) {
 101                 debug("No I2C MUX width specified\n");
 102                 return -EINVAL;
 103         }
 104
 105         debug("Device %s at 0x%x with width %d\n",
 106               dev->name, priv->addr, priv->width);
 107
 108         return 0;
 109 }
 110
 111 static int pca954x_probe(struct udevice *dev)
 112 {
 113         if (IS_ENABLED(CONFIG_DM_GPIO)) {
 114                 struct pca954x_priv *priv = dev_get_priv(dev);
 115                 int err;
 116
 117                 err = gpio_request_by_name(dev, "reset-gpios", 0,
 118                                 &priv->gpio_mux_reset, GPIOD_IS_OUT);
 119
 120                 /* it's optional so only bail if we get a real error */
 121                 if (err && (err != -ENOENT))
 122                         return err;
 123
 124                 /* dm will take care of polarity */
 125                 if (dm_gpio_is_valid(&priv->gpio_mux_reset))
 126                         dm_gpio_set_value(&priv->gpio_mux_reset, 0);
 127         }
 128
 129         return 0;
 130 }
 131
 132 static int pca954x_remove(struct udevice *dev)
 133 {
 134         if (IS_ENABLED(CONFIG_DM_GPIO)) {
 135                 struct pca954x_priv *priv = dev_get_priv(dev);
 136
 137                 if (dm_gpio_is_valid(&priv->gpio_mux_reset))
 138                         dm_gpio_free(dev, &priv->gpio_mux_reset);
 139         }
 140
 141         return 0;
 142 }
 143
 144 U_BOOT_DRIVER(pca954x) = {
 145         .name = "pca954x",
 146         .id = UCLASS_I2C_MUX,
 147         .of_match = pca954x_ids,
 148         .probe = pca954x_probe,
 149         .remove = pca954x_remove,
 150         .ops = &pca954x_ops,
 151         .ofdata_to_platdata = pca954x_ofdata_to_platdata,
 152         .priv_auto_alloc_size = sizeof(struct pca954x_priv),
 153 };