commit 3d59d2716a71bbcccccd00ea39f42b76a32db0e9
author Stu Hsieh <stu.hsieh@mediatek.com> Tue Jun 04 18:11:55 2019 +0800
committer Alex Van Damme <atv@google.com> Wed Sep 09 12:07:07 2020 -0700
tree 7ae013134ed97f5e323f329ca5942335fb24ed24
parent 1104e29f5e62f999ae32232bdf9b7696dcd45091

mtk-mipicsi: add function to support SerDes for link number

This patch add function to support SerDes for link number.

Mt2712 can serve at most four camera link for each mipicsi port.
Therefore, driver need to know how many camera link in SerDes and
set the mipicsi HW to serve.

The value "link_reg" defined in dts, and use it to get the link status
for SerDes.

Signed-off-by: Stu Hsieh <stu.hsieh@mediatek.com>

drivers/media/platform/mtk-mipicsi/mtk_mipicsi.c

diff --git a/drivers/media/platform/mtk-mipicsi/mtk_mipicsi.c b/drivers/media/platform/mtk-mipicsi/mtk_mipicsi.c
index 9b5983b..ab703e3 100644
--- a/drivers/media/platform/mtk-mipicsi/mtk_mipicsi.c
+++ b/drivers/media/platform/mtk-mipicsi/mtk_mipicsi.c
@@ -143,6 +143,7 @@
 	struct v4l2_async_subdev asd;
 	struct v4l2_subdev *subdev;
 	unsigned int max_vc;
+	u32 link_reg;
 };
 
 struct mtk_mipicsi_channel {
@@ -257,12 +258,37 @@
 };
 #endif /* CONFIG_DEBUG_FS */
 
+static int get_subdev_register(struct mtk_mipicsi_dev *mipicsi,
+			       struct v4l2_dbg_register *reg)
+{
+	struct v4l2_subdev *sd = mipicsi->mipicsi_sd.subdev;
+	struct device *dev = &mipicsi->pdev->dev;
+	int ret = 0;
+
+	reg->match.type = V4L2_CHIP_MATCH_SUBDEV;
+	reg->match.addr = 0;
+	ret = v4l2_subdev_call(sd, core, g_register, reg);
+	if (ret != 2) {
+		dev_err(dev, "mipicsi get des register 0x%llx fail, ret=%d\n",
+		reg->reg, ret);
+		return -EIO;
+	}
+
+	dev_info(dev, "read DES [reg/val/ret] is [0x%llx/0x%llx/%d]\n",
+		 reg->reg, reg->val, ret);
+
+	return ret;
+}
+
+
 static int get_subdev_link(struct mtk_mipicsi_dev *mipicsi,
 	unsigned int *link, u8 *link_reg_val)
 {
 	struct device *dev = &mipicsi->pdev->dev;
 	struct mtk_mipicsi_subdev *sd = &mipicsi->mipicsi_sd;
-
+	struct v4l2_dbg_register reg;
+	int ret = 0;
+	unsigned int index = 0;
 
 	if (sd->max_vc == 1) {
 		*link = 1;
@@ -274,6 +300,24 @@
 
 	dev_info(dev, "mtk mipicsi support %d channel\n", sd->max_vc);
 
+	memset(&reg, 0, sizeof(reg));
+	/*get camera link number*/
+	reg.reg = sd->link_reg;
+	ret = get_subdev_register(mipicsi, &reg);
+	if (ret < 0)
+		return ret;
+
+	*link = 0;
+	for (index = 0; index < sd->max_vc; index++) {
+		if ((reg.val & 0x01) == 0x01) {
+			*link += 1;
+			*link_reg_val |= (0x01 << index);
+		}
+		reg.val >>= 1;
+	}
+
+	dev_info(dev, "%u camera linked to sub device\n", *link);
+
 	return 0;
 }
 
@@ -1199,6 +1243,13 @@
 		sd->max_vc = 1;
 	}
 
+	ret = of_property_read_u32(dev->of_node, "mediatek,serdes_link_reg",
+				   &sd->link_reg);
+	if (ret != 0) {
+		dev_info(dev, "not set mediatek,serdes_link_reg, can't read subdev link number\n");
+		sd->link_reg = 0x0;
+	}
+
 	/* get and parse seninf_mux_camsv */
 	camsv_num = of_count_phandle_with_args(dev->of_node,
 		"mediatek,seninf_mux_camsv", NULL);