add lvds1024*800

hc

2024-01-31 f70575805708cabdedea7498aaa3f710fde4d920

 kernel/drivers/gpu/drm/drm_dp_dual_mode_helper.c
..
..
@@ -20,13 +20,15 @@
20
20
  * OTHER DEALINGS IN THE SOFTWARE.
21
21
  */
22
22
 
23
+#include <linux/delay.h>
23
24
 #include <linux/errno.h>
24
25
 #include <linux/export.h>
25
26
 #include <linux/i2c.h>
26
27
 #include <linux/slab.h>
27
28
 #include <linux/string.h>
29
+
28
30
 #include <drm/drm_dp_dual_mode_helper.h>
29
-#include <drm/drmP.h>
31
+#include <drm/drm_print.h>
30
32
 
31
33
 /**
32
34
  * DOC: dp dual mode helpers
..
..
@@ -60,23 +62,45 @@
60
62
 ssize_t drm_dp_dual_mode_read(struct i2c_adapter *adapter,
61
63
 			      u8 offset, void *buffer, size_t size)
62
64
 {
65
+	u8 zero = 0;
66
+	char *tmpbuf = NULL;
67
+	/*
68
+	 * As sub-addressing is not supported by all adaptors,
69
+	 * always explicitly read from the start and discard
70
+	 * any bytes that come before the requested offset.
71
+	 * This way, no matter whether the adaptor supports it
72
+	 * or not, we'll end up reading the proper data.
73
+	 */
63
74
 	struct i2c_msg msgs[] = {
64
75
 		{
65
76
 			.addr = DP_DUAL_MODE_SLAVE_ADDRESS,
66
77
 			.flags = 0,
67
78
 			.len = 1,
68
-			.buf = &offset,
79
+			.buf = &zero,
69
80
 		},
70
81
 		{
71
82
 			.addr = DP_DUAL_MODE_SLAVE_ADDRESS,
72
83
 			.flags = I2C_M_RD,
73
-			.len = size,
84
+			.len = size + offset,
74
85
 			.buf = buffer,
75
86
 		},
76
87
 	};
77
88
 	int ret;
78
89
 
90
+	if (offset) {
91
+		tmpbuf = kmalloc(size + offset, GFP_KERNEL);
92
+		if (!tmpbuf)
93
+			return -ENOMEM;
94
+
95
+		msgs[1].buf = tmpbuf;
96
+	}
97
+
79
98
 	ret = i2c_transfer(adapter, msgs, ARRAY_SIZE(msgs));
99
+	if (tmpbuf)
100
+		memcpy(buffer, tmpbuf + offset, size);
101
+
102
+	kfree(tmpbuf);
103
+
80
104
 	if (ret < 0)
81
105
 		return ret;
82
106
 	if (ret != ARRAY_SIZE(msgs))
..
..
@@ -203,18 +227,6 @@
203
227
 	if (ret)
204
228
 		return DRM_DP_DUAL_MODE_UNKNOWN;
205
229
 
206
-	/*
207
-	 * Sigh. Some (maybe all?) type 1 adaptors are broken and ack
208
-	 * the offset but ignore it, and instead they just always return
209
-	 * data from the start of the HDMI ID buffer. So for a broken
210
-	 * type 1 HDMI adaptor a single byte read will always give us
211
-	 * 0x44, and for a type 1 DVI adaptor it should give 0x00
212
-	 * (assuming it implements any registers). Fortunately neither
213
-	 * of those values will match the type 2 signature of the
214
-	 * DP_DUAL_MODE_ADAPTOR_ID register so we can proceed with
215
-	 * the type 2 adaptor detection safely even in the presence
216
-	 * of broken type 1 adaptors.
217
-	 */
218
230
 	ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_ADAPTOR_ID,
219
231
 				    &adaptor_id, sizeof(adaptor_id));
220
232
 	DRM_DEBUG_KMS("DP dual mode adaptor ID: %02x (err %zd)\n",
..
..
@@ -229,11 +241,10 @@
229
241
 				return DRM_DP_DUAL_MODE_TYPE2_DVI;
230
242
 		}
231
243
 		/*
232
-		 * If neither a proper type 1 ID nor a broken type 1 adaptor
233
-		 * as described above, assume type 1, but let the user know
234
-		 * that we may have misdetected the type.
244
+		 * If not a proper type 1 ID, still assume type 1, but let
245
+		 * the user know that we may have misdetected the type.
235
246
 		 */
236
-		if (!is_type1_adaptor(adaptor_id) && adaptor_id != hdmi_id[0])
247
+		if (!is_type1_adaptor(adaptor_id))
237
248
 			DRM_ERROR("Unexpected DP dual mode adaptor ID %02x\n",
238
249
 				  adaptor_id);
239
250
 
..
..
@@ -337,10 +348,8 @@
337
348
  * @enable: enable (as opposed to disable) the TMDS output buffers
338
349
  *
339
350
  * Set the state of the TMDS output buffers in the adaptor. For
340
- * type2 this is set via the DP_DUAL_MODE_TMDS_OEN register. As
341
- * some type 1 adaptors have problems with registers (see comments
342
- * in drm_dp_dual_mode_detect()) we avoid touching the register,
343
- * making this function a no-op on type 1 adaptors.
351
+ * type2 this is set via the DP_DUAL_MODE_TMDS_OEN register.
352
+ * Type1 adaptors do not support any register writes.
344
353
  *
345
354
  * Returns:
346
355
  * 0 on success, negative error code on failure