| 1 | |
| 2 | |
| 3 | * Linux kernel module helpers.
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| 4 |
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| 5 |
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| 6 | #include <linux/of.h>
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| 7 | #include <linux/module.h>
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| 8 | #include <linux/slab.h>
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| 9 | #include <linux/string.h>
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| 10 |
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| 11 | ssize_t of_modalias(const struct device_node *np, char *str, ssize_t len)
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| 12 | {
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| 13 | const char *compat;
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| 14 | char *c;
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| 15 | struct property *p;
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| 16 | ssize_t csize;
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| 17 | ssize_t tsize;
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| 18 |
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| 19 | |
| 20 | * Prevent a kernel oops in vsnprintf() -- it only allows passing a
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| 21 | * NULL ptr when the length is also 0. Also filter out the negative
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| 22 | * lengths...
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| 23 |
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| 24 | if ((len > 0 && !str) || len < 0)
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| 25 | return -EINVAL;
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| 26 |
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| 27 |
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| 28 |
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| 29 | csize = snprintf(str, len, "of:N%pOFn%c%s", np, 'T',
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| 30 | of_node_get_device_type(np));
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| 31 | tsize = csize;
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| 32 | if (csize >= len)
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| 33 | csize = len > 0 ? len - 1 : 0;
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| 34 | len -= csize;
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| 35 | str += csize;
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| 36 |
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| 37 | of_property_for_each_string(np, "compatible", p, compat) {
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| 38 | csize = snprintf(str, len, "C%s", compat);
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| 39 | tsize += csize;
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| 40 | if (csize >= len)
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| 41 | continue;
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| 42 | for (c = str; c; ) {
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| 43 | c = strchr(c, ' ');
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| 44 | if (c)
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| 45 | *c++ = '_';
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| 46 | }
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| 47 | len -= csize;
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| 48 | str += csize;
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| 49 | }
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| 50 |
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| 51 | return tsize;
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| 52 | }
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| 53 |
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| 54 | int of_request_module(const struct device_node *np)
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| 55 | {
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| 56 | char *str;
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| 57 | ssize_t size;
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| 58 | int ret;
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| 59 |
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| 60 | if (!np)
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| 61 | return -ENODEV;
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| 62 |
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| 63 | size = of_modalias(np, NULL, 0);
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| 64 | if (size < 0)
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| 65 | return size;
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| 66 |
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| 67 |
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| 68 | size++;
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| 69 |
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| 70 | str = kmalloc(size, GFP_KERNEL);
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| 71 | if (!str)
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| 72 | return -ENOMEM;
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| 73 |
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| 74 | of_modalias(np, str, size);
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| 75 | str[size - 1] = '\0';
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| 76 | ret = request_module(str);
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| 77 | kfree(str);
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| 78 |
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| 79 | return ret;
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| 80 | }
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| 81 | EXPORT_SYMBOL_GPL(of_request_module);
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