1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* Copyright (C) IBM Corporation 2023 */ |
3 | |
4 | #include <linux/cdev.h> |
5 | #include <linux/device.h> |
6 | #include <linux/fs.h> |
7 | #include <linux/fsi.h> |
8 | #include <linux/module.h> |
9 | #include <linux/mod_devicetable.h> |
10 | |
11 | #include "fsi-master-i2cr.h" |
12 | #include "fsi-slave.h" |
13 | |
14 | struct i2cr_scom { |
15 | struct device dev; |
16 | struct cdev cdev; |
17 | struct fsi_master_i2cr *i2cr; |
18 | }; |
19 | |
20 | static loff_t i2cr_scom_llseek(struct file *file, loff_t offset, int whence) |
21 | { |
22 | switch (whence) { |
23 | case SEEK_CUR: |
24 | break; |
25 | case SEEK_SET: |
26 | file->f_pos = offset; |
27 | break; |
28 | default: |
29 | return -EINVAL; |
30 | } |
31 | |
32 | return offset; |
33 | } |
34 | |
35 | static ssize_t i2cr_scom_read(struct file *filep, char __user *buf, size_t len, loff_t *offset) |
36 | { |
37 | struct i2cr_scom *scom = filep->private_data; |
38 | u64 data; |
39 | int ret; |
40 | |
41 | if (len != sizeof(data)) |
42 | return -EINVAL; |
43 | |
44 | ret = fsi_master_i2cr_read(i2cr: scom->i2cr, addr: (u32)*offset, data: &data); |
45 | if (ret) |
46 | return ret; |
47 | |
48 | ret = copy_to_user(to: buf, from: &data, n: len); |
49 | if (ret) |
50 | return ret; |
51 | |
52 | return len; |
53 | } |
54 | |
55 | static ssize_t i2cr_scom_write(struct file *filep, const char __user *buf, size_t len, |
56 | loff_t *offset) |
57 | { |
58 | struct i2cr_scom *scom = filep->private_data; |
59 | u64 data; |
60 | int ret; |
61 | |
62 | if (len != sizeof(data)) |
63 | return -EINVAL; |
64 | |
65 | ret = copy_from_user(to: &data, from: buf, n: len); |
66 | if (ret) |
67 | return ret; |
68 | |
69 | ret = fsi_master_i2cr_write(i2cr: scom->i2cr, addr: (u32)*offset, data); |
70 | if (ret) |
71 | return ret; |
72 | |
73 | return len; |
74 | } |
75 | |
76 | static const struct file_operations i2cr_scom_fops = { |
77 | .owner = THIS_MODULE, |
78 | .open = simple_open, |
79 | .llseek = i2cr_scom_llseek, |
80 | .read = i2cr_scom_read, |
81 | .write = i2cr_scom_write, |
82 | }; |
83 | |
84 | static int i2cr_scom_probe(struct device *dev) |
85 | { |
86 | struct fsi_device *fsi_dev = to_fsi_dev(dev); |
87 | struct i2cr_scom *scom; |
88 | int didx; |
89 | int ret; |
90 | |
91 | if (!is_fsi_master_i2cr(master: fsi_dev->slave->master)) |
92 | return -ENODEV; |
93 | |
94 | scom = devm_kzalloc(dev, size: sizeof(*scom), GFP_KERNEL); |
95 | if (!scom) |
96 | return -ENOMEM; |
97 | |
98 | scom->i2cr = to_fsi_master_i2cr(fsi_dev->slave->master); |
99 | dev_set_drvdata(dev, data: scom); |
100 | |
101 | scom->dev.type = &fsi_cdev_type; |
102 | scom->dev.parent = dev; |
103 | device_initialize(dev: &scom->dev); |
104 | |
105 | ret = fsi_get_new_minor(fdev: fsi_dev, type: fsi_dev_scom, out_dev: &scom->dev.devt, out_index: &didx); |
106 | if (ret) |
107 | return ret; |
108 | |
109 | dev_set_name(dev: &scom->dev, name: "scom%d" , didx); |
110 | cdev_init(&scom->cdev, &i2cr_scom_fops); |
111 | ret = cdev_device_add(cdev: &scom->cdev, dev: &scom->dev); |
112 | if (ret) |
113 | fsi_free_minor(dev: scom->dev.devt); |
114 | |
115 | return ret; |
116 | } |
117 | |
118 | static int i2cr_scom_remove(struct device *dev) |
119 | { |
120 | struct i2cr_scom *scom = dev_get_drvdata(dev); |
121 | |
122 | cdev_device_del(cdev: &scom->cdev, dev: &scom->dev); |
123 | fsi_free_minor(dev: scom->dev.devt); |
124 | |
125 | return 0; |
126 | } |
127 | |
128 | static const struct of_device_id i2cr_scom_of_ids[] = { |
129 | { .compatible = "ibm,i2cr-scom" }, |
130 | { } |
131 | }; |
132 | MODULE_DEVICE_TABLE(of, i2cr_scom_of_ids); |
133 | |
134 | static const struct fsi_device_id i2cr_scom_ids[] = { |
135 | { 0x5, FSI_VERSION_ANY }, |
136 | { } |
137 | }; |
138 | |
139 | static struct fsi_driver i2cr_scom_driver = { |
140 | .id_table = i2cr_scom_ids, |
141 | .drv = { |
142 | .name = "i2cr_scom" , |
143 | .bus = &fsi_bus_type, |
144 | .of_match_table = i2cr_scom_of_ids, |
145 | .probe = i2cr_scom_probe, |
146 | .remove = i2cr_scom_remove, |
147 | } |
148 | }; |
149 | |
150 | module_fsi_driver(i2cr_scom_driver); |
151 | |
152 | MODULE_AUTHOR("Eddie James <eajames@linux.ibm.com>" ); |
153 | MODULE_DESCRIPTION("IBM I2C Responder SCOM driver" ); |
154 | MODULE_LICENSE("GPL" ); |
155 | |