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", 0 },
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");
161