drivers/net/dsa/xrs700x/xrs700x_i2c.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2020 NovaTech LLC
   4  * George McCollister <george.mccollister@gmail.com>
   5  */
   6
   7 #include <linux/bits.h>
   8 #include <linux/i2c.h>
   9 #include <linux/module.h>
  10 #include "xrs700x.h"
  11 #include "xrs700x_reg.h"
  12
  13 struct xrs700x_i2c_cmd {
  14         __be32 reg;
  15         __be16 val;
  16 } __packed;
  17
  18 static int xrs700x_i2c_reg_read(void *context, unsigned int reg,
  19                                 unsigned int *val)
  20 {
  21         struct device *dev = context;
  22         struct i2c_client *i2c = to_i2c_client(dev);
  23         struct xrs700x_i2c_cmd cmd;
  24         int ret;
  25
  26         cmd.reg = cpu_to_be32(reg | 1);
  27
  28         ret = i2c_master_send(i2c, (char *)&cmd.reg, sizeof(cmd.reg));
  29         if (ret < 0) {
  30                 dev_err(dev, "xrs i2c_master_send returned %d\n", ret);
  31                 return ret;
  32         }
  33
  34         ret = i2c_master_recv(i2c, (char *)&cmd.val, sizeof(cmd.val));
  35         if (ret < 0) {
  36                 dev_err(dev, "xrs i2c_master_recv returned %d\n", ret);
  37                 return ret;
  38         }
  39
  40         *val = be16_to_cpu(cmd.val);
  41         return 0;
  42 }
  43
  44 static int xrs700x_i2c_reg_write(void *context, unsigned int reg,
  45                                  unsigned int val)
  46 {
  47         struct device *dev = context;
  48         struct i2c_client *i2c = to_i2c_client(dev);
  49         struct xrs700x_i2c_cmd cmd;
  50         int ret;
  51
  52         cmd.reg = cpu_to_be32(reg);
  53         cmd.val = cpu_to_be16(val);
  54
  55         ret = i2c_master_send(i2c, (char *)&cmd, sizeof(cmd));
  56         if (ret < 0) {
  57                 dev_err(dev, "xrs i2c_master_send returned %d\n", ret);
  58                 return ret;
  59         }
  60
  61         return 0;
  62 }
  63
  64 static const struct regmap_config xrs700x_i2c_regmap_config = {
  65         .val_bits = 16,
  66         .reg_stride = 2,
  67         .reg_bits = 32,
  68         .pad_bits = 0,
  69         .write_flag_mask = 0,
  70         .read_flag_mask = 0,
  71         .reg_read = xrs700x_i2c_reg_read,
  72         .reg_write = xrs700x_i2c_reg_write,
  73         .max_register = 0,
  74         .cache_type = REGCACHE_NONE,
  75         .reg_format_endian = REGMAP_ENDIAN_BIG,
  76         .val_format_endian = REGMAP_ENDIAN_BIG
  77 };
  78
  79 static int xrs700x_i2c_probe(struct i2c_client *i2c,
  80                              const struct i2c_device_id *i2c_id)
  81 {
  82         struct xrs700x *priv;
  83         int ret;
  84
  85         priv = xrs700x_switch_alloc(&i2c->dev, i2c);
  86         if (!priv)
  87                 return -ENOMEM;
  88
  89         priv->regmap = devm_regmap_init(&i2c->dev, NULL, &i2c->dev,
  90                                         &xrs700x_i2c_regmap_config);
  91         if (IS_ERR(priv->regmap)) {
  92                 ret = PTR_ERR(priv->regmap);
  93                 dev_err(&i2c->dev, "Failed to initialize regmap: %d\n", ret);
  94                 return ret;
  95         }
  96
  97         i2c_set_clientdata(i2c, priv);
  98
  99         ret = xrs700x_switch_register(priv);
 100
 101         /* Main DSA driver may not be started yet. */
 102         if (ret)
 103                 return ret;
 104
 105         return 0;
 106 }
 107
 108 static int xrs700x_i2c_remove(struct i2c_client *i2c)
 109 {
 110         struct xrs700x *priv = i2c_get_clientdata(i2c);
 111
 112         if (!priv)
 113                 return 0;
 114
 115         xrs700x_switch_remove(priv);
 116
 117         i2c_set_clientdata(i2c, NULL);
 118
 119         return 0;
 120 }
 121
 122 static void xrs700x_i2c_shutdown(struct i2c_client *i2c)
 123 {
 124         struct xrs700x *priv = i2c_get_clientdata(i2c);
 125
 126         if (!priv)
 127                 return;
 128
 129         xrs700x_switch_shutdown(priv);
 130
 131         i2c_set_clientdata(i2c, NULL);
 132 }
 133
 134 static const struct i2c_device_id xrs700x_i2c_id[] = {
 135         { "xrs700x-switch", 0 },
 136         {},
 137 };
 138
 139 MODULE_DEVICE_TABLE(i2c, xrs700x_i2c_id);
 140
 141 static const struct of_device_id __maybe_unused xrs700x_i2c_dt_ids[] = {
 142         { .compatible = "arrow,xrs7003e", .data = &xrs7003e_info },
 143         { .compatible = "arrow,xrs7003f", .data = &xrs7003f_info },
 144         { .compatible = "arrow,xrs7004e", .data = &xrs7004e_info },
 145         { .compatible = "arrow,xrs7004f", .data = &xrs7004f_info },
 146         {},
 147 };
 148 MODULE_DEVICE_TABLE(of, xrs700x_i2c_dt_ids);
 149
 150 static struct i2c_driver xrs700x_i2c_driver = {
 151         .driver = {
 152                 .name   = "xrs700x-i2c",
 153                 .of_match_table = of_match_ptr(xrs700x_i2c_dt_ids),
 154         },
 155         .probe  = xrs700x_i2c_probe,
 156         .remove = xrs700x_i2c_remove,
 157         .shutdown = xrs700x_i2c_shutdown,
 158         .id_table = xrs700x_i2c_id,
 159 };
 160
 161 module_i2c_driver(xrs700x_i2c_driver);
 162
 163 MODULE_AUTHOR("George McCollister <george.mccollister@gmail.com>");
 164 MODULE_DESCRIPTION("Arrow SpeedChips XRS700x DSA I2C driver");
 165 MODULE_LICENSE("GPL v2");