Re: [PATCHv2 13/56] drm/omap: dsi: switch dsi_vc_send_long/short to mipi_dsi_msg

[Sebastian Reichel <sre@kernel.org>]

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Hi Laurent,

On Tue, Feb 25, 2020 at 06:30:01PM +0200, Laurent Pinchart wrote:
> On Tue, Feb 25, 2020 at 12:20:43AM +0100, Sebastian Reichel wrote:
> > Simplify the DSI encoder by using mipi_dsi_msg for
> > dsi_vc_send_long and dsi_vc_send_short. Further improvements
> > require cleaning up the channel allocation code first.
> > 
> > Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
> > ---
> >  drivers/gpu/drm/omapdrm/dss/dsi.c | 92 +++++++++++++++----------------
> >  1 file changed, 45 insertions(+), 47 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c
> > index 9b5b078beb6d..4899bfa2d76f 100644
> > --- a/drivers/gpu/drm/omapdrm/dss/dsi.c
> > +++ b/drivers/gpu/drm/omapdrm/dss/dsi.c
> > @@ -2599,30 +2599,36 @@ static inline void dsi_vc_write_long_payload(struct dsi_data *dsi, int channel,
> >  	dsi_write_reg(dsi, DSI_VC_LONG_PACKET_PAYLOAD(channel), val);
> >  }
> >  
> > -static int dsi_vc_send_long(struct dsi_data *dsi, int channel, u8 data_type,
> > -			    const u8 *data, u16 len, u8 ecc)
> > +static int dsi_vc_send_long(struct dsi_data *dsi,
> > +			    const struct mipi_dsi_msg *msg)
> >  {
> > +	struct mipi_dsi_packet pkg;
> >  	/*u32 val; */
> >  	int i;
> >  	const u8 *p;
> >  	int r = 0;
> >  	u8 b1, b2, b3, b4;
> >  
> > +	r = mipi_dsi_create_packet(&pkg, msg);
> > +	if (r < 0)
> > +		return r;
> > +
> >  	if (dsi->debug_write)
> > -		DSSDBG("dsi_vc_send_long, %d bytes\n", len);
> > +		DSSDBG("dsi_vc_send_long, %d bytes\n", msg->tx_len);
> >  
> >  	/* len + header */
> > -	if (dsi->vc[channel].tx_fifo_size * 32 * 4 < len + 4) {
> > +	if (dsi->vc[msg->channel].tx_fifo_size * 32 * 4 < msg->tx_len + 4) {
> >  		DSSERR("unable to send long packet: packet too long.\n");
> >  		return -EINVAL;
> >  	}
> >  
> > -	dsi_vc_config_source(dsi, channel, DSI_VC_SOURCE_L4);
> > +	dsi_vc_config_source(dsi, msg->channel, DSI_VC_SOURCE_L4);
> >  
> > -	dsi_vc_write_long_header(dsi, channel, data_type, len, ecc);
> > +	dsi_vc_write_long_header(dsi, msg->channel, msg->type, msg->tx_len,
> > +				 pkg.header[3]);
> 
> mipi_dsi_create_packet() never sets header[3]. I suppose that's not an
> issue as we were always passing ecc as 0 to this function, but you may
> want to drop mipi_dsi_create_packet() above and just hardcode 0 here.

sure.

> >  
> > -	p = data;
> > -	for (i = 0; i < len >> 2; i++) {
> > +	p = msg->tx_buf;
> > +	for (i = 0; i < msg->tx_len >> 2; i++) {
> >  		if (dsi->debug_write)
> >  			DSSDBG("\tsending full packet %d\n", i);
> >  
> > @@ -2631,10 +2637,10 @@ static int dsi_vc_send_long(struct dsi_data *dsi, int channel, u8 data_type,
> >  		b3 = *p++;
> >  		b4 = *p++;
> >  
> > -		dsi_vc_write_long_payload(dsi, channel, b1, b2, b3, b4);
> > +		dsi_vc_write_long_payload(dsi, msg->channel, b1, b2, b3, b4);
> >  	}
> >  
> > -	i = len % 4;
> > +	i = msg->tx_len % 4;
> >  	if (i) {
> >  		b1 = 0; b2 = 0; b3 = 0;
> >  
> > @@ -2656,64 +2662,64 @@ static int dsi_vc_send_long(struct dsi_data *dsi, int channel, u8 data_type,
> >  			break;
> >  		}
> >  
> > -		dsi_vc_write_long_payload(dsi, channel, b1, b2, b3, 0);
> > +		dsi_vc_write_long_payload(dsi, msg->channel, b1, b2, b3, 0);
> >  	}
> >  
> >  	return r;
> >  }
> >  
> > -static int dsi_vc_send_short(struct dsi_data *dsi, int channel, u8 data_type,
> > -			     u16 data, u8 ecc)
> > +static int dsi_vc_send_short(struct dsi_data *dsi,
> > +			     const struct mipi_dsi_msg *msg)
> >  {
> > +	struct mipi_dsi_packet pkg;
> 
> s/pkg/pkt/ (or packet)

Ack.

-- Sebastian

> >  	u32 r;
> > -	u8 data_id;
> > +
> > +	r = mipi_dsi_create_packet(&pkg, msg);
> > +	if (r < 0)
> > +		return r;
> >  
> >  	WARN_ON(!dsi_bus_is_locked(dsi));
> >  
> >  	if (dsi->debug_write)
> >  		DSSDBG("dsi_vc_send_short(ch%d, dt %#x, b1 %#x, b2 %#x)\n",
> > -				channel,
> > -				data_type, data & 0xff, (data >> 8) & 0xff);
> > +				msg->channel,
> > +				msg->type, pkg.header[1], pkg.header[2]);
> >  
> > -	dsi_vc_config_source(dsi, channel, DSI_VC_SOURCE_L4);
> > +	dsi_vc_config_source(dsi, msg->channel, DSI_VC_SOURCE_L4);
> >  
> > -	if (FLD_GET(dsi_read_reg(dsi, DSI_VC_CTRL(channel)), 16, 16)) {
> > +	if (FLD_GET(dsi_read_reg(dsi, DSI_VC_CTRL(msg->channel)), 16, 16)) {
> >  		DSSERR("ERROR FIFO FULL, aborting transfer\n");
> >  		return -EINVAL;
> >  	}
> >  
> > -	data_id = data_type | channel << 6;
> > -
> > -	r = (data_id << 0) | (data << 8) | (ecc << 24);
> > +	r = pkg.header[3] << 24 | pkg.header[2] << 16 | pkg.header[1] << 8 |
> > +	    pkg.header[0];
> 
> OK, this justifies using mipi_dsi_create_packet(), so you can skip the
> related comments in earlier patches.
> 
> > -	dsi_write_reg(dsi, DSI_VC_SHORT_PACKET_HEADER(channel), r);
> > +	dsi_write_reg(dsi, DSI_VC_SHORT_PACKET_HEADER(msg->channel), r);
> >  
> >  	return 0;
> >  }
> >  
> >  static int dsi_vc_send_null(struct dsi_data *dsi, int channel)
> >  {
> > -	return dsi_vc_send_long(dsi, channel, MIPI_DSI_NULL_PACKET, NULL, 0, 0);
> > +	const struct mipi_dsi_msg msg = {
> > +		.channel = channel,
> > +		.type = MIPI_DSI_NULL_PACKET,
> > +	};
> > +
> > +	return dsi_vc_send_long(dsi, &msg);
> >  }
> >  
> >  static int dsi_vc_write_common(struct omap_dss_device *dssdev,
> >  			       const struct mipi_dsi_msg *msg)
> >  {
> >  	struct dsi_data *dsi = to_dsi_data(dssdev);
> > -	struct mipi_dsi_packet packet;
> >  	int r;
> >  
> > -	r = mipi_dsi_create_packet(&packet, msg);
> > -	if (r < 0)
> > -		return r;
> > -
> > -	if (mipi_dsi_packet_format_is_short(msg->type)) {
> > -		u16 data = packet.header[1] | (packet.header[2] << 8);
> > -		r = dsi_vc_send_short(dsi, msg->channel, msg->type, data, 0);
> > -	} else {
> > -		r = dsi_vc_send_long(dsi, msg->channel, msg->type,
> > -						   msg->tx_buf, msg->tx_len, 0);
> > -	}
> > +	if (mipi_dsi_packet_format_is_short(msg->type))
> > +		r = dsi_vc_send_short(dsi, msg);
> > +	else
> > +		r = dsi_vc_send_long(dsi, msg);
> >  
> >  	if (r < 0)
> >  		return r;
> > @@ -2853,10 +2859,10 @@ static int dsi_vc_dcs_read(struct omap_dss_device *dssdev,
> >  			   const struct mipi_dsi_msg *msg)
> >  {
> >  	struct dsi_data *dsi = to_dsi_data(dssdev);
> > +	u8 cmd = ((u8*) msg->tx_buf)[0];
> >  	int r;
> > -	u8 dcs_cmd = ((u8*) msg->tx_buf)[0];
> >  
> > -	r = dsi_vc_send_short(dsi, msg->channel, MIPI_DSI_DCS_READ, dcs_cmd, 0);
> > +	r = dsi_vc_send_short(dsi, msg);
> >  	if (r)
> >  		goto err;
> >  
> > @@ -2877,7 +2883,7 @@ static int dsi_vc_dcs_read(struct omap_dss_device *dssdev,
> >  	return 0;
> >  err:
> >  	DSSERR("dsi_vc_dcs_read(ch %d, cmd 0x%02x) failed\n",
> > -		msg->channel, dcs_cmd);
> > +		msg->channel, cmd);
> >  	return r;
> >  }
> >  
> > @@ -2885,17 +2891,9 @@ static int dsi_vc_generic_read(struct omap_dss_device *dssdev,
> >  			       const struct mipi_dsi_msg *msg)
> >  {
> >  	struct dsi_data *dsi = to_dsi_data(dssdev);
> > -	struct mipi_dsi_packet packet;
> > -	u16 data;
> >  	int r;
> >  
> > -	r = mipi_dsi_create_packet(&packet, msg);
> > -	if (r < 0)
> > -		goto err;
> > -
> > -	data = packet.header[1] | (packet.header[2] << 8);
> > -
> > -	r = dsi_vc_send_short(dsi, msg->channel, msg->type, data, 0);
> > +	r = dsi_vc_send_short(dsi, msg);
> >  	if (r)
> >  		goto err;
> >  
> 
> -- 
> Regards,
> 
> Laurent Pinchart

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