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14#include <linux/kernel.h>
15#include <linux/cdev.h>
16#include <linux/err.h>
17#include <linux/module.h>
18#include <linux/platform_device.h>
19#include <linux/of.h>
20#include <linux/of_reserved_mem.h>
21#include <linux/dma-mapping.h>
22#include <linux/slab.h>
23#include <linux/uaccess.h>
24#include <linux/io.h>
25#include <linux/qcom_scm.h>
26
27#define QCOM_RMTFS_MEM_DEV_MAX (MINORMASK + 1)
28
29static dev_t qcom_rmtfs_mem_major;
30
31struct qcom_rmtfs_mem {
32 struct device dev;
33 struct cdev cdev;
34
35 void *base;
36 phys_addr_t addr;
37 phys_addr_t size;
38
39 unsigned int client_id;
40
41 unsigned int perms;
42};
43
44static ssize_t qcom_rmtfs_mem_show(struct device *dev,
45 struct device_attribute *attr,
46 char *buf);
47
48static DEVICE_ATTR(phys_addr, 0400, qcom_rmtfs_mem_show, NULL);
49static DEVICE_ATTR(size, 0400, qcom_rmtfs_mem_show, NULL);
50static DEVICE_ATTR(client_id, 0400, qcom_rmtfs_mem_show, NULL);
51
52static ssize_t qcom_rmtfs_mem_show(struct device *dev,
53 struct device_attribute *attr,
54 char *buf)
55{
56 struct qcom_rmtfs_mem *rmtfs_mem = container_of(dev,
57 struct qcom_rmtfs_mem,
58 dev);
59
60 if (attr == &dev_attr_phys_addr)
61 return sprintf(buf, "%pa\n", &rmtfs_mem->addr);
62 if (attr == &dev_attr_size)
63 return sprintf(buf, "%pa\n", &rmtfs_mem->size);
64 if (attr == &dev_attr_client_id)
65 return sprintf(buf, "%d\n", rmtfs_mem->client_id);
66
67 return -EINVAL;
68}
69
70static struct attribute *qcom_rmtfs_mem_attrs[] = {
71 &dev_attr_phys_addr.attr,
72 &dev_attr_size.attr,
73 &dev_attr_client_id.attr,
74 NULL
75};
76ATTRIBUTE_GROUPS(qcom_rmtfs_mem);
77
78static int qcom_rmtfs_mem_open(struct inode *inode, struct file *filp)
79{
80 struct qcom_rmtfs_mem *rmtfs_mem = container_of(inode->i_cdev,
81 struct qcom_rmtfs_mem,
82 cdev);
83
84 get_device(&rmtfs_mem->dev);
85 filp->private_data = rmtfs_mem;
86
87 return 0;
88}
89static ssize_t qcom_rmtfs_mem_read(struct file *filp,
90 char __user *buf, size_t count, loff_t *f_pos)
91{
92 struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data;
93
94 if (*f_pos >= rmtfs_mem->size)
95 return 0;
96
97 if (*f_pos + count >= rmtfs_mem->size)
98 count = rmtfs_mem->size - *f_pos;
99
100 if (copy_to_user(buf, rmtfs_mem->base + *f_pos, count))
101 return -EFAULT;
102
103 *f_pos += count;
104 return count;
105}
106
107static ssize_t qcom_rmtfs_mem_write(struct file *filp,
108 const char __user *buf, size_t count,
109 loff_t *f_pos)
110{
111 struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data;
112
113 if (*f_pos >= rmtfs_mem->size)
114 return 0;
115
116 if (*f_pos + count >= rmtfs_mem->size)
117 count = rmtfs_mem->size - *f_pos;
118
119 if (copy_from_user(rmtfs_mem->base + *f_pos, buf, count))
120 return -EFAULT;
121
122 *f_pos += count;
123 return count;
124}
125
126static int qcom_rmtfs_mem_release(struct inode *inode, struct file *filp)
127{
128 struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data;
129
130 put_device(&rmtfs_mem->dev);
131
132 return 0;
133}
134
135static const struct file_operations qcom_rmtfs_mem_fops = {
136 .owner = THIS_MODULE,
137 .open = qcom_rmtfs_mem_open,
138 .read = qcom_rmtfs_mem_read,
139 .write = qcom_rmtfs_mem_write,
140 .release = qcom_rmtfs_mem_release,
141 .llseek = default_llseek,
142};
143
144static void qcom_rmtfs_mem_release_device(struct device *dev)
145{
146 struct qcom_rmtfs_mem *rmtfs_mem = container_of(dev,
147 struct qcom_rmtfs_mem,
148 dev);
149
150 kfree(rmtfs_mem);
151}
152
153static int qcom_rmtfs_mem_probe(struct platform_device *pdev)
154{
155 struct device_node *node = pdev->dev.of_node;
156 struct qcom_scm_vmperm perms[2];
157 struct reserved_mem *rmem;
158 struct qcom_rmtfs_mem *rmtfs_mem;
159 u32 client_id;
160 u32 vmid;
161 int ret;
162
163 rmem = of_reserved_mem_lookup(node);
164 if (!rmem) {
165 dev_err(&pdev->dev, "failed to acquire memory region\n");
166 return -EINVAL;
167 }
168
169 ret = of_property_read_u32(node, "qcom,client-id", &client_id);
170 if (ret) {
171 dev_err(&pdev->dev, "failed to parse \"qcom,client-id\"\n");
172 return ret;
173
174 }
175
176 rmtfs_mem = kzalloc(sizeof(*rmtfs_mem), GFP_KERNEL);
177 if (!rmtfs_mem)
178 return -ENOMEM;
179
180 rmtfs_mem->addr = rmem->base;
181 rmtfs_mem->client_id = client_id;
182 rmtfs_mem->size = rmem->size;
183
184 device_initialize(&rmtfs_mem->dev);
185 rmtfs_mem->dev.parent = &pdev->dev;
186 rmtfs_mem->dev.groups = qcom_rmtfs_mem_groups;
187 rmtfs_mem->dev.release = qcom_rmtfs_mem_release_device;
188
189 rmtfs_mem->base = devm_memremap(&rmtfs_mem->dev, rmtfs_mem->addr,
190 rmtfs_mem->size, MEMREMAP_WC);
191 if (IS_ERR(rmtfs_mem->base)) {
192 dev_err(&pdev->dev, "failed to remap rmtfs_mem region\n");
193 ret = PTR_ERR(rmtfs_mem->base);
194 goto put_device;
195 }
196
197 cdev_init(&rmtfs_mem->cdev, &qcom_rmtfs_mem_fops);
198 rmtfs_mem->cdev.owner = THIS_MODULE;
199
200 dev_set_name(&rmtfs_mem->dev, "qcom_rmtfs_mem%d", client_id);
201 rmtfs_mem->dev.id = client_id;
202 rmtfs_mem->dev.devt = MKDEV(MAJOR(qcom_rmtfs_mem_major), client_id);
203
204 ret = cdev_device_add(&rmtfs_mem->cdev, &rmtfs_mem->dev);
205 if (ret) {
206 dev_err(&pdev->dev, "failed to add cdev: %d\n", ret);
207 goto put_device;
208 }
209
210 ret = of_property_read_u32(node, "qcom,vmid", &vmid);
211 if (ret < 0 && ret != -EINVAL) {
212 dev_err(&pdev->dev, "failed to parse qcom,vmid\n");
213 goto remove_cdev;
214 } else if (!ret) {
215 perms[0].vmid = QCOM_SCM_VMID_HLOS;
216 perms[0].perm = QCOM_SCM_PERM_RW;
217 perms[1].vmid = vmid;
218 perms[1].perm = QCOM_SCM_PERM_RW;
219
220 rmtfs_mem->perms = BIT(QCOM_SCM_VMID_HLOS);
221 ret = qcom_scm_assign_mem(rmtfs_mem->addr, rmtfs_mem->size,
222 &rmtfs_mem->perms, perms, 2);
223 if (ret < 0) {
224 dev_err(&pdev->dev, "assign memory failed\n");
225 goto remove_cdev;
226 }
227 }
228
229 dev_set_drvdata(&pdev->dev, rmtfs_mem);
230
231 return 0;
232
233remove_cdev:
234 cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev);
235put_device:
236 put_device(&rmtfs_mem->dev);
237
238 return ret;
239}
240
241static int qcom_rmtfs_mem_remove(struct platform_device *pdev)
242{
243 struct qcom_rmtfs_mem *rmtfs_mem = dev_get_drvdata(&pdev->dev);
244 struct qcom_scm_vmperm perm;
245
246 if (rmtfs_mem->perms) {
247 perm.vmid = QCOM_SCM_VMID_HLOS;
248 perm.perm = QCOM_SCM_PERM_RW;
249
250 qcom_scm_assign_mem(rmtfs_mem->addr, rmtfs_mem->size,
251 &rmtfs_mem->perms, &perm, 1);
252 }
253
254 cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev);
255 put_device(&rmtfs_mem->dev);
256
257 return 0;
258}
259
260static const struct of_device_id qcom_rmtfs_mem_of_match[] = {
261 { .compatible = "qcom,rmtfs-mem" },
262 {}
263};
264MODULE_DEVICE_TABLE(of, qcom_rmtfs_mem_of_match);
265
266static struct platform_driver qcom_rmtfs_mem_driver = {
267 .probe = qcom_rmtfs_mem_probe,
268 .remove = qcom_rmtfs_mem_remove,
269 .driver = {
270 .name = "qcom_rmtfs_mem",
271 .of_match_table = qcom_rmtfs_mem_of_match,
272 },
273};
274
275static int qcom_rmtfs_mem_init(void)
276{
277 int ret;
278
279 ret = alloc_chrdev_region(&qcom_rmtfs_mem_major, 0,
280 QCOM_RMTFS_MEM_DEV_MAX, "qcom_rmtfs_mem");
281 if (ret < 0) {
282 pr_err("qcom_rmtfs_mem: failed to allocate char dev region\n");
283 return ret;
284 }
285
286 ret = platform_driver_register(&qcom_rmtfs_mem_driver);
287 if (ret < 0) {
288 pr_err("qcom_rmtfs_mem: failed to register rmtfs_mem driver\n");
289 unregister_chrdev_region(qcom_rmtfs_mem_major,
290 QCOM_RMTFS_MEM_DEV_MAX);
291 }
292
293 return ret;
294}
295module_init(qcom_rmtfs_mem_init);
296
297static void qcom_rmtfs_mem_exit(void)
298{
299 platform_driver_unregister(&qcom_rmtfs_mem_driver);
300 unregister_chrdev_region(qcom_rmtfs_mem_major, QCOM_RMTFS_MEM_DEV_MAX);
301}
302module_exit(qcom_rmtfs_mem_exit);
303
304MODULE_AUTHOR("Linaro Ltd");
305MODULE_DESCRIPTION("Qualcomm Remote Filesystem memory driver");
306MODULE_LICENSE("GPL v2");
307
