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
 13struct xrs700x_i2c_cmd {
 14	__be32 reg;
 15	__be16 val;
 16} __packed;
 17
 18static 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
 44static 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
 64static 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
 79static 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
107static 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
117static 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
129static const struct i2c_device_id xrs700x_i2c_id[] = {
130	{ "xrs700x-switch", 0 },
131	{},
132};
133
134MODULE_DEVICE_TABLE(i2c, xrs700x_i2c_id);
135
136static 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};
143MODULE_DEVICE_TABLE(of, xrs700x_i2c_dt_ids);
144
145static 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
156module_i2c_driver(xrs700x_i2c_driver);
157
158MODULE_AUTHOR("George McCollister <george.mccollister@gmail.com>");
159MODULE_DESCRIPTION("Arrow SpeedChips XRS700x DSA I2C driver");
160MODULE_LICENSE("GPL v2");