dsa/xrs700x/xrs700x_i2c.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Copyright (C) 2020 NovaTech LLC
0004  * George McCollister <george.mccollister@gmail.com>
0005  */
0006
0007 #include <linux/bits.h>
0008 #include <linux/i2c.h>
0009 #include <linux/module.h>
0010 #include "xrs700x.h"
0011 #include "xrs700x_reg.h"
0012
0013 struct xrs700x_i2c_cmd {
0014     __be32 reg;
0015     __be16 val;
0016 } __packed;
0017
0018 static int xrs700x_i2c_reg_read(void *context, unsigned int reg,
0019                 unsigned int *val)
0020 {
0021     struct device *dev = context;
0022     struct i2c_client *i2c = to_i2c_client(dev);
0023     struct xrs700x_i2c_cmd cmd;
0024     int ret;
0025
0026     cmd.reg = cpu_to_be32(reg | 1);
0027
0028     ret = i2c_master_send(i2c, (char *)&cmd.reg, sizeof(cmd.reg));
0029     if (ret < 0) {
0030         dev_err(dev, "xrs i2c_master_send returned %d\n", ret);
0031         return ret;
0032     }
0033
0034     ret = i2c_master_recv(i2c, (char *)&cmd.val, sizeof(cmd.val));
0035     if (ret < 0) {
0036         dev_err(dev, "xrs i2c_master_recv returned %d\n", ret);
0037         return ret;
0038     }
0039
0040     *val = be16_to_cpu(cmd.val);
0041     return 0;
0042 }
0043
0044 static int xrs700x_i2c_reg_write(void *context, unsigned int reg,
0045                  unsigned int val)
0046 {
0047     struct device *dev = context;
0048     struct i2c_client *i2c = to_i2c_client(dev);
0049     struct xrs700x_i2c_cmd cmd;
0050     int ret;
0051
0052     cmd.reg = cpu_to_be32(reg);
0053     cmd.val = cpu_to_be16(val);
0054
0055     ret = i2c_master_send(i2c, (char *)&cmd, sizeof(cmd));
0056     if (ret < 0) {
0057         dev_err(dev, "xrs i2c_master_send returned %d\n", ret);
0058         return ret;
0059     }
0060
0061     return 0;
0062 }
0063
0064 static const struct regmap_config xrs700x_i2c_regmap_config = {
0065     .val_bits = 16,
0066     .reg_stride = 2,
0067     .reg_bits = 32,
0068     .pad_bits = 0,
0069     .write_flag_mask = 0,
0070     .read_flag_mask = 0,
0071     .reg_read = xrs700x_i2c_reg_read,
0072     .reg_write = xrs700x_i2c_reg_write,
0073     .max_register = 0,
0074     .cache_type = REGCACHE_NONE,
0075     .reg_format_endian = REGMAP_ENDIAN_BIG,
0076     .val_format_endian = REGMAP_ENDIAN_BIG
0077 };
0078
0079 static int xrs700x_i2c_probe(struct i2c_client *i2c,
0080                  const struct i2c_device_id *i2c_id)
0081 {
0082     struct xrs700x *priv;
0083     int ret;
0084
0085     priv = xrs700x_switch_alloc(&i2c->dev, i2c);
0086     if (!priv)
0087         return -ENOMEM;
0088
0089     priv->regmap = devm_regmap_init(&i2c->dev, NULL, &i2c->dev,
0090                     &xrs700x_i2c_regmap_config);
0091     if (IS_ERR(priv->regmap)) {
0092         ret = PTR_ERR(priv->regmap);
0093         dev_err(&i2c->dev, "Failed to initialize regmap: %d\n", ret);
0094         return ret;
0095     }
0096
0097     i2c_set_clientdata(i2c, priv);
0098
0099     ret = xrs700x_switch_register(priv);
0100
0101     /* Main DSA driver may not be started yet. */
0102     if (ret)
0103         return ret;
0104
0105     return 0;
0106 }
0107
0108 static int xrs700x_i2c_remove(struct i2c_client *i2c)
0109 {
0110     struct xrs700x *priv = i2c_get_clientdata(i2c);
0111
0112     if (!priv)
0113         return 0;
0114
0115     xrs700x_switch_remove(priv);
0116
0117     i2c_set_clientdata(i2c, NULL);
0118
0119     return 0;
0120 }
0121
0122 static void xrs700x_i2c_shutdown(struct i2c_client *i2c)
0123 {
0124     struct xrs700x *priv = i2c_get_clientdata(i2c);
0125
0126     if (!priv)
0127         return;
0128
0129     xrs700x_switch_shutdown(priv);
0130
0131     i2c_set_clientdata(i2c, NULL);
0132 }
0133
0134 static const struct i2c_device_id xrs700x_i2c_id[] = {
0135     { "xrs700x-switch", 0 },
0136     {},
0137 };
0138
0139 MODULE_DEVICE_TABLE(i2c, xrs700x_i2c_id);
0140
0141 static const struct of_device_id __maybe_unused xrs700x_i2c_dt_ids[] = {
0142     { .compatible = "arrow,xrs7003e", .data = &xrs7003e_info },
0143     { .compatible = "arrow,xrs7003f", .data = &xrs7003f_info },
0144     { .compatible = "arrow,xrs7004e", .data = &xrs7004e_info },
0145     { .compatible = "arrow,xrs7004f", .data = &xrs7004f_info },
0146     {},
0147 };
0148 MODULE_DEVICE_TABLE(of, xrs700x_i2c_dt_ids);
0149
0150 static struct i2c_driver xrs700x_i2c_driver = {
0151     .driver = {
0152         .name   = "xrs700x-i2c",
0153         .of_match_table = of_match_ptr(xrs700x_i2c_dt_ids),
0154     },
0155     .probe  = xrs700x_i2c_probe,
0156     .remove = xrs700x_i2c_remove,
0157     .shutdown = xrs700x_i2c_shutdown,
0158     .id_table = xrs700x_i2c_id,
0159 };
0160
0161 module_i2c_driver(xrs700x_i2c_driver);
0162
0163 MODULE_AUTHOR("George McCollister <george.mccollister@gmail.com>");
0164 MODULE_DESCRIPTION("Arrow SpeedChips XRS700x DSA I2C driver");
0165 MODULE_LICENSE("GPL v2");