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 {
  81         struct xrs700x *priv;
  82         int ret;
  83
  84         priv = xrs700x_switch_alloc(&i2c->dev, i2c);
  85         if (!priv)
  86                 return -ENOMEM;
  87
  88         priv->regmap = devm_regmap_init(&i2c->dev, NULL, &i2c->dev,
  89                                         &xrs700x_i2c_regmap_config);
  90         if (IS_ERR(priv->regmap)) {
  91                 ret = PTR_ERR(priv->regmap);
  92                 dev_err(&i2c->dev, "Failed to initialize regmap: %d\n", ret);
  93                 return ret;
  94         }
  95
  96         i2c_set_clientdata(i2c, priv);
  97
  98         ret = xrs700x_switch_register(priv);
  99
 100         /* Main DSA driver may not be started yet. */
 101         if (ret)
 102                 return ret;
 103
 104         return 0;
 105 }
 106
 107 static void xrs700x_i2c_remove(struct i2c_client *i2c)
 108 {
 109         struct xrs700x *priv = i2c_get_clientdata(i2c);
 110
 111         if (!priv)
 112                 return;
 113
 114         xrs700x_switch_remove(priv);
 115 }
 116
 117 static void xrs700x_i2c_shutdown(struct i2c_client *i2c)
 118 {
 119         struct xrs700x *priv = i2c_get_clientdata(i2c);
 120
 121         if (!priv)
 122                 return;
 123
 124         xrs700x_switch_shutdown(priv);
 125
 126         i2c_set_clientdata(i2c, NULL);
 127 }
 128
 129 static const struct i2c_device_id xrs700x_i2c_id[] = {
 130         { "xrs700x-switch" },
 131         {}
 132 };
 133
 134 MODULE_DEVICE_TABLE(i2c, xrs700x_i2c_id);
 135
 136 static const struct of_device_id __maybe_unused xrs700x_i2c_dt_ids[] = {
 137         { .compatible = "arrow,xrs7003e", .data = &xrs7003e_info },
 138         { .compatible = "arrow,xrs7003f", .data = &xrs7003f_info },
 139         { .compatible = "arrow,xrs7004e", .data = &xrs7004e_info },
 140         { .compatible = "arrow,xrs7004f", .data = &xrs7004f_info },
 141         {},
 142 };
 143 MODULE_DEVICE_TABLE(of, xrs700x_i2c_dt_ids);
 144
 145 static struct i2c_driver xrs700x_i2c_driver = {
 146         .driver = {
 147                 .name   = "xrs700x-i2c",
 148                 .of_match_table = of_match_ptr(xrs700x_i2c_dt_ids),
 149         },
 150         .probe = xrs700x_i2c_probe,
 151         .remove = xrs700x_i2c_remove,
 152         .shutdown = xrs700x_i2c_shutdown,
 153         .id_table = xrs700x_i2c_id,
 154 };
 155
 156 module_i2c_driver(xrs700x_i2c_driver);
 157
 158 MODULE_AUTHOR("George McCollister <george.mccollister@gmail.com>");
 159 MODULE_DESCRIPTION("Arrow SpeedChips XRS700x DSA I2C driver");
 160 MODULE_LICENSE("GPL v2");