[PATCH v1 4/5] media: cadence: Add support for external dphy

Jack Zhu
2023-05-12T10:32:50Z

Add support for external MIPI D-PHY.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jack Zhu <jack.zhu@starfivetech.com>
---
drivers/media/platform/cadence/cdns-csi2rx.c | 66 +++++++++++++++++---
1 file changed, 56 insertions(+), 10 deletions(-)

diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
index bb78f54e944e..18d9c36cd560 100644
--- a/drivers/media/platform/cadence/cdns-csi2rx.c
+++ b/drivers/media/platform/cadence/cdns-csi2rx.c
@@ -31,6 +31,12 @@
#define CSI2RX_STATIC_CFG_DLANE_MAP(llane, plane) ((plane) << (16 + (llane) * 4))
#define CSI2RX_STATIC_CFG_LANES_MASK GENMASK(11, 8)

+#define CSI2RX_DPHY_LANE_CTRL_REG 0x40
+#define CSI2RX_DPHY_CL_RST BIT(16)
+#define CSI2RX_DPHY_DL_RST(i) BIT((i) + 12)
+#define CSI2RX_DPHY_CL_EN BIT(4)
+#define CSI2RX_DPHY_DL_EN(i) BIT(i)
+
#define CSI2RX_STREAM_BASE(n) (((n) + 1) * 0x100)

#define CSI2RX_STREAM_CTRL_REG(n) (CSI2RX_STREAM_BASE(n) + 0x000)
@@ -105,6 +111,24 @@ static void csi2rx_reset(struct csi2rx_priv *csi2rx)
writel(0, csi2rx->base + CSI2RX_SOFT_RESET_REG);
}

+static int csi2rx_configure_ext_dphy(struct csi2rx_priv *csi2rx)
+{
+ union phy_configure_opts opts = { };
+ int ret;
+
+ ret = phy_power_on(csi2rx->dphy);
+ if (ret)
+ return ret;
+
+ ret = phy_configure(csi2rx->dphy, &opts);
+ if (ret) {
+ phy_power_off(csi2rx->dphy);
+ return ret;
+ }
+
+ return 0;
+}
+
static int csi2rx_start(struct csi2rx_priv *csi2rx)
{
unsigned int i;
@@ -144,6 +168,17 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
if (ret)
goto err_disable_pclk;

+ /* Enable DPHY clk and data lanes. */
+ if (csi2rx->dphy) {
+ reg = CSI2RX_DPHY_CL_EN | CSI2RX_DPHY_CL_RST;
+ for (i = 0; i < csi2rx->num_lanes; i++) {
+ reg |= CSI2RX_DPHY_DL_EN(csi2rx->lanes[i] - 1);
+ reg |= CSI2RX_DPHY_DL_RST(csi2rx->lanes[i] - 1);
+ }
+
+ writel(reg, csi2rx->base + CSI2RX_DPHY_LANE_CTRL_REG);
+ }
+
/*
* Create a static mapping between the CSI virtual channels
* and the output stream.
@@ -177,10 +212,22 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
goto err_disable_pixclk;

reset_control_deassert(csi2rx->sys_rst);
+
+ if (csi2rx->dphy) {
+ ret = csi2rx_configure_ext_dphy(csi2rx);
+ if (ret) {
+ dev_err(csi2rx->dev,
+ "Failed to configure external DPHY: %d\n", ret);
+ goto err_disable_sysclk;
+ }
+ }
+
clk_disable_unprepare(csi2rx->p_clk);

return 0;

+err_disable_sysclk:
+ clk_disable_unprepare(csi2rx->sys_clk);
err_disable_pixclk:
for (; i > 0; i--) {
reset_control_assert(csi2rx->pixel_rst[i - 1]);
@@ -213,6 +260,13 @@ static void csi2rx_stop(struct csi2rx_priv *csi2rx)

if (v4l2_subdev_call(csi2rx->source_subdev, video, s_stream, false))
dev_warn(csi2rx->dev, "Couldn't disable our subdev\n");
+
+ if (csi2rx->dphy) {
+ writel(0, csi2rx->base + CSI2RX_DPHY_LANE_CTRL_REG);
+
+ if (phy_power_off(csi2rx->dphy))
+ dev_warn(csi2rx->dev, "Couldn't power off DPHY\n");
+ }
}

static int csi2rx_s_stream(struct v4l2_subdev *subdev, int enable)
@@ -328,15 +382,6 @@ static int csi2rx_get_resources(struct csi2rx_priv *csi2rx,
return PTR_ERR(csi2rx->dphy);
}

- /*
- * FIXME: Once we'll have external D-PHY support, the check
- * will need to be removed.
- */
- if (csi2rx->dphy) {
- dev_err(&pdev->dev, "External D-PHY not supported yet\n");
- return -EINVAL;
- }
-
ret = clk_prepare_enable(csi2rx->p_clk);
if (ret) {
dev_err(&pdev->dev, "Couldn't prepare and enable P clock\n");
@@ -366,7 +411,7 @@ static int csi2rx_get_resources(struct csi2rx_priv *csi2rx,
* FIXME: Once we'll have internal D-PHY support, the check
* will need to be removed.
*/
- if (csi2rx->has_internal_dphy) {
+ if (!csi2rx->dphy && csi2rx->has_internal_dphy) {
dev_err(&pdev->dev, "Internal D-PHY not supported yet\n");
return -EINVAL;
}
@@ -492,6 +537,7 @@ static int csi2rx_probe(struct platform_device *pdev)
dev_info(&pdev->dev,
"Probed CSI2RX with %u/%u lanes, %u streams, %s D-PHY\n",
csi2rx->num_lanes, csi2rx->max_lanes, csi2rx->max_streams,
+ csi2rx->dphy ? "external" :
csi2rx->has_internal_dphy ? "internal" : "no");

return 0;
--
2.34.1