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path: root/drivers/gpu/drm/nouveau/nouveau_i2c.c
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Diffstat (limited to 'drivers/gpu/drm/nouveau/nouveau_i2c.c')
-rw-r--r--drivers/gpu/drm/nouveau/nouveau_i2c.c42
1 files changed, 42 insertions, 0 deletions
diff --git a/drivers/gpu/drm/nouveau/nouveau_i2c.c b/drivers/gpu/drm/nouveau/nouveau_i2c.c
index 316a3c7e6eb4..cb0cb34440c6 100644
--- a/drivers/gpu/drm/nouveau/nouveau_i2c.c
+++ b/drivers/gpu/drm/nouveau/nouveau_i2c.c
@@ -278,3 +278,45 @@ nouveau_i2c_find(struct drm_device *dev, int index)
return i2c->chan;
}
+bool
+nouveau_probe_i2c_addr(struct nouveau_i2c_chan *i2c, int addr)
+{
+ uint8_t buf[] = { 0 };
+ struct i2c_msg msgs[] = {
+ {
+ .addr = addr,
+ .flags = 0,
+ .len = 1,
+ .buf = buf,
+ },
+ {
+ .addr = addr,
+ .flags = I2C_M_RD,
+ .len = 1,
+ .buf = buf,
+ }
+ };
+
+ return i2c_transfer(&i2c->adapter, msgs, 2) == 2;
+}
+
+int
+nouveau_i2c_identify(struct drm_device *dev, const char *what,
+ struct i2c_board_info *info, int index)
+{
+ struct nouveau_i2c_chan *i2c = nouveau_i2c_find(dev, index);
+ int i;
+
+ NV_DEBUG(dev, "Probing %ss on I2C bus: %d\n", what, index);
+
+ for (i = 0; info[i].addr; i++) {
+ if (nouveau_probe_i2c_addr(i2c, info[i].addr)) {
+ NV_INFO(dev, "Detected %s: %s\n", what, info[i].type);
+ return i;
+ }
+ }
+
+ NV_DEBUG(dev, "No devices found.\n");
+
+ return -ENODEV;
+}