media: i2c: adv748x: add adv748x driver

Provide support for the ADV7481 and ADV7482.

The driver is modelled with 4 subdevices to allow simultaneous streaming
from the AFE (Analog front end) and HDMI inputs though two CSI TX
entities.

The HDMI entity is linked to the TXA CSI bus, whilst the AFE is linked
to the TXB CSI bus.

The driver is based on a prototype by Koji Matsuoka in the Renesas BSP,
and an earlier rework by Niklas Söderlund.

Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

1 files changed, 327 insertions, 0 deletions

diff --git a/drivers/media/i2c/adv748x/adv748x-csi2.c b/drivers/media/i2c/adv748x/adv748x-csi2.c
new file mode 100644
index 000000000000..b4fee7f52d6a
--- /dev/null
+++ b/drivers/media/i2c/adv748x/adv748x-csi2.c
@@ -0,0 +1,327 @@
+/*
+ * Driver for Analog Devices ADV748X CSI-2 Transmitter
+ *
+ * Copyright (C) 2017 Renesas Electronics Corp.
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/mutex.h>
+
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-ioctl.h>
+
+#include "adv748x.h"
+
+static bool is_txa(struct adv748x_csi2 *tx)
+{
+	return tx == &tx->state->txa;
+}
+
+static int adv748x_csi2_set_virtual_channel(struct adv748x_csi2 *tx,
+					    unsigned int vc)
+{
+	return tx_write(tx, ADV748X_CSI_VC_REF, vc << ADV748X_CSI_VC_REF_SHIFT);
+}
+
+/**
+ * adv748x_csi2_register_link : Register and link internal entities
+ *
+ * @tx: CSI2 private entity
+ * @v4l2_dev: Video registration device
+ * @src: Source subdevice to establish link
+ * @src_pad: Pad number of source to link to this @tx
+ *
+ * Ensure that the subdevice is registered against the v4l2_device, and link the
+ * source pad to the sink pad of the CSI2 bus entity.
+ */
+static int adv748x_csi2_register_link(struct adv748x_csi2 *tx,
+				      struct v4l2_device *v4l2_dev,
+				      struct v4l2_subdev *src,
+				      unsigned int src_pad)
+{
+	int enabled = MEDIA_LNK_FL_ENABLED;
+	int ret;
+
+	/*
+	 * Dynamic linking of the AFE is not supported.
+	 * Register the links as immutable.
+	 */
+	enabled |= MEDIA_LNK_FL_IMMUTABLE;
+
+	if (!src->v4l2_dev) {
+		ret = v4l2_device_register_subdev(v4l2_dev, src);
+		if (ret)
+			return ret;
+	}
+
+	return media_create_pad_link(&src->entity, src_pad,
+				     &tx->sd.entity, ADV748X_CSI2_SINK,
+				     enabled);
+}
+
+/* -----------------------------------------------------------------------------
+ * v4l2_subdev_internal_ops
+ *
+ * We use the internal registered operation to be able to ensure that our
+ * incremental subdevices (not connected in the forward path) can be registered
+ * against the resulting video path and media device.
+ */
+
+static int adv748x_csi2_registered(struct v4l2_subdev *sd)
+{
+	struct adv748x_csi2 *tx = adv748x_sd_to_csi2(sd);
+	struct adv748x_state *state = tx->state;
+
+	adv_dbg(state, "Registered %s (%s)", is_txa(tx) ? "TXA":"TXB",
+			sd->name);
+
+	/*
+	 * The adv748x hardware allows the AFE to route through the TXA, however
+	 * this is not currently supported in this driver.
+	 *
+	 * Link HDMI->TXA, and AFE->TXB directly.
+	 */
+	if (is_txa(tx)) {
+		return adv748x_csi2_register_link(tx, sd->v4l2_dev,
+						  &state->hdmi.sd,
+						  ADV748X_HDMI_SOURCE);
+	} else {
+		return adv748x_csi2_register_link(tx, sd->v4l2_dev,
+						  &state->afe.sd,
+						  ADV748X_AFE_SOURCE);
+	}
+}
+
+static const struct v4l2_subdev_internal_ops adv748x_csi2_internal_ops = {
+	.registered = adv748x_csi2_registered,
+};
+
+/* -----------------------------------------------------------------------------
+ * v4l2_subdev_video_ops
+ */
+
+static int adv748x_csi2_s_stream(struct v4l2_subdev *sd, int enable)
+{
+	struct adv748x_csi2 *tx = adv748x_sd_to_csi2(sd);
+	struct v4l2_subdev *src;
+
+	src = adv748x_get_remote_sd(&tx->pads[ADV748X_CSI2_SINK]);
+	if (!src)
+		return -EPIPE;
+
+	return v4l2_subdev_call(src, video, s_stream, enable);
+}
+
+static const struct v4l2_subdev_video_ops adv748x_csi2_video_ops = {
+	.s_stream = adv748x_csi2_s_stream,
+};
+
+/* -----------------------------------------------------------------------------
+ * v4l2_subdev_pad_ops
+ *
+ * The CSI2 bus pads are ignorant to the data sizes or formats.
+ * But we must support setting the pad formats for format propagation.
+ */
+
+static struct v4l2_mbus_framefmt *
+adv748x_csi2_get_pad_format(struct v4l2_subdev *sd,
+			    struct v4l2_subdev_pad_config *cfg,
+			    unsigned int pad, u32 which)
+{
+	struct adv748x_csi2 *tx = adv748x_sd_to_csi2(sd);
+
+	if (which == V4L2_SUBDEV_FORMAT_TRY)
+		return v4l2_subdev_get_try_format(sd, cfg, pad);
+
+	return &tx->format;
+}
+
+static int adv748x_csi2_get_format(struct v4l2_subdev *sd,
+				   struct v4l2_subdev_pad_config *cfg,
+				   struct v4l2_subdev_format *sdformat)
+{
+	struct adv748x_csi2 *tx = adv748x_sd_to_csi2(sd);
+	struct adv748x_state *state = tx->state;
+	struct v4l2_mbus_framefmt *mbusformat;
+
+	mbusformat = adv748x_csi2_get_pad_format(sd, cfg, sdformat->pad,
+						 sdformat->which);
+	if (!mbusformat)
+		return -EINVAL;
+
+	mutex_lock(&state->mutex);
+
+	sdformat->format = *mbusformat;
+
+	mutex_unlock(&state->mutex);
+
+	return 0;
+}
+
+static int adv748x_csi2_set_format(struct v4l2_subdev *sd,
+				   struct v4l2_subdev_pad_config *cfg,
+				   struct v4l2_subdev_format *sdformat)
+{
+	struct adv748x_csi2 *tx = adv748x_sd_to_csi2(sd);
+	struct adv748x_state *state = tx->state;
+	struct v4l2_mbus_framefmt *mbusformat;
+	int ret = 0;
+
+	mbusformat = adv748x_csi2_get_pad_format(sd, cfg, sdformat->pad,
+						 sdformat->which);
+	if (!mbusformat)
+		return -EINVAL;
+
+	mutex_lock(&state->mutex);
+
+	if (sdformat->pad == ADV748X_CSI2_SOURCE) {
+		const struct v4l2_mbus_framefmt *sink_fmt;
+
+		sink_fmt = adv748x_csi2_get_pad_format(sd, cfg,
+						       ADV748X_CSI2_SINK,
+						       sdformat->which);
+
+		if (!sink_fmt) {
+			ret = -EINVAL;
+			goto unlock;
+		}
+
+		sdformat->format = *sink_fmt;
+	}
+
+	*mbusformat = sdformat->format;
+
+unlock:
+	mutex_unlock(&state->mutex);
+
+	return ret;
+}
+
+static const struct v4l2_subdev_pad_ops adv748x_csi2_pad_ops = {
+	.get_fmt = adv748x_csi2_get_format,
+	.set_fmt = adv748x_csi2_set_format,
+};
+
+/* -----------------------------------------------------------------------------
+ * v4l2_subdev_ops
+ */
+
+static const struct v4l2_subdev_ops adv748x_csi2_ops = {
+	.video = &adv748x_csi2_video_ops,
+	.pad = &adv748x_csi2_pad_ops,
+};
+
+/* -----------------------------------------------------------------------------
+ * Subdev module and controls
+ */
+
+int adv748x_csi2_set_pixelrate(struct v4l2_subdev *sd, s64 rate)
+{
+	struct v4l2_ctrl *ctrl;
+
+	ctrl = v4l2_ctrl_find(sd->ctrl_handler, V4L2_CID_PIXEL_RATE);
+	if (!ctrl)
+		return -EINVAL;
+
+	return v4l2_ctrl_s_ctrl_int64(ctrl, rate);
+}
+
+static int adv748x_csi2_s_ctrl(struct v4l2_ctrl *ctrl)
+{
+	switch (ctrl->id) {
+	case V4L2_CID_PIXEL_RATE:
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct v4l2_ctrl_ops adv748x_csi2_ctrl_ops = {
+	.s_ctrl = adv748x_csi2_s_ctrl,
+};
+
+static int adv748x_csi2_init_controls(struct adv748x_csi2 *tx)
+{
+	struct v4l2_ctrl *ctrl;
+
+	v4l2_ctrl_handler_init(&tx->ctrl_hdl, 1);
+
+	ctrl = v4l2_ctrl_new_std(&tx->ctrl_hdl, &adv748x_csi2_ctrl_ops,
+				 V4L2_CID_PIXEL_RATE, 1, INT_MAX, 1, 1);
+
+	tx->sd.ctrl_handler = &tx->ctrl_hdl;
+	if (tx->ctrl_hdl.error) {
+		v4l2_ctrl_handler_free(&tx->ctrl_hdl);
+		return tx->ctrl_hdl.error;
+	}
+
+	return v4l2_ctrl_handler_setup(&tx->ctrl_hdl);
+}
+
+int adv748x_csi2_init(struct adv748x_state *state, struct adv748x_csi2 *tx)
+{
+	struct device_node *ep;
+	int ret;
+
+	/* We can not use container_of to get back to the state with two TXs */
+	tx->state = state;
+	tx->page = is_txa(tx) ? ADV748X_PAGE_TXA : ADV748X_PAGE_TXB;
+
+	ep = state->endpoints[is_txa(tx) ? ADV748X_PORT_TXA : ADV748X_PORT_TXB];
+	if (!ep) {
+		adv_err(state, "No endpoint found for %s\n",
+				is_txa(tx) ? "txa" : "txb");
+		return -ENODEV;
+	}
+
+	/* Initialise the virtual channel */
+	adv748x_csi2_set_virtual_channel(tx, 0);
+
+	adv748x_subdev_init(&tx->sd, state, &adv748x_csi2_ops,
+			    MEDIA_ENT_F_UNKNOWN,
+			    is_txa(tx) ? "txa" : "txb");
+
+	/* Ensure that matching is based upon the endpoint fwnodes */
+	tx->sd.fwnode = of_fwnode_handle(ep);
+
+	/* Register internal ops for incremental subdev registration */
+	tx->sd.internal_ops = &adv748x_csi2_internal_ops;
+
+	tx->pads[ADV748X_CSI2_SINK].flags = MEDIA_PAD_FL_SINK;
+	tx->pads[ADV748X_CSI2_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
+
+	ret = media_entity_pads_init(&tx->sd.entity, ADV748X_CSI2_NR_PADS,
+				     tx->pads);
+	if (ret)
+		return ret;
+
+	ret = adv748x_csi2_init_controls(tx);
+	if (ret)
+		goto err_free_media;
+
+	ret = v4l2_async_register_subdev(&tx->sd);
+	if (ret)
+		goto err_free_ctrl;
+
+	return 0;
+
+err_free_ctrl:
+	v4l2_ctrl_handler_free(&tx->ctrl_hdl);
+err_free_media:
+	media_entity_cleanup(&tx->sd.entity);
+
+	return ret;
+}
+
+void adv748x_csi2_cleanup(struct adv748x_csi2 *tx)
+{
+	v4l2_async_unregister_subdev(&tx->sd);
+	media_entity_cleanup(&tx->sd.entity);
+	v4l2_ctrl_handler_free(&tx->ctrl_hdl);
+}