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");
161