drm/bridge: samsung-dsim: add flag to control header FIFO wait

Exynos7870's DSIM device doesn't require waiting for the header FIFO
during a MIPI DSI transfer. Add a flag in the driver data in order to
control said behavior.

Signed-off-by: Kaustabh Chakraborty <kauschluss@disroot.org>
Signed-off-by: Inki Dae <inki.dae@samsung.com

Author: Kaustabh Chakraborty

drivers/gpu/drm/bridge/samsung-dsim.c

@@ -418,6 +418,7 @@ static const struct samsung_dsim_driver_data exynos3_dsi_driver_data = {
 	.has_clklane_stop = 1,
 	.num_clks = 2,
 	.max_freq = 1000,
+	.wait_for_hdr_fifo = 1,
 	.wait_for_reset = 1,
 	.num_bits_resol = 11,
 	.pll_p_offset = 13,
@@ -438,6 +439,7 @@ static const struct samsung_dsim_driver_data exynos4_dsi_driver_data = {
 	.has_clklane_stop = 1,
 	.num_clks = 2,
 	.max_freq = 1000,
+	.wait_for_hdr_fifo = 1,
 	.wait_for_reset = 1,
 	.num_bits_resol = 11,
 	.pll_p_offset = 13,
@@ -456,6 +458,7 @@ static const struct samsung_dsim_driver_data exynos5_dsi_driver_data = {
 	.has_legacy_status_reg = 1,
 	.num_clks = 2,
 	.max_freq = 1000,
+	.wait_for_hdr_fifo = 1,
 	.wait_for_reset = 1,
 	.num_bits_resol = 11,
 	.pll_p_offset = 13,
@@ -474,6 +477,7 @@ static const struct samsung_dsim_driver_data exynos5433_dsi_driver_data = {
 	.has_clklane_stop = 1,
 	.num_clks = 5,
 	.max_freq = 1500,
+	.wait_for_hdr_fifo = 1,
 	.wait_for_reset = 0,
 	.num_bits_resol = 12,
 	.pll_p_offset = 13,
@@ -492,6 +496,7 @@ static const struct samsung_dsim_driver_data exynos5422_dsi_driver_data = {
 	.has_clklane_stop = 1,
 	.num_clks = 2,
 	.max_freq = 1500,
+	.wait_for_hdr_fifo = 1,
 	.wait_for_reset = 1,
 	.num_bits_resol = 12,
 	.pll_p_offset = 13,
@@ -510,6 +515,7 @@ static const struct samsung_dsim_driver_data imx8mm_dsi_driver_data = {
 	.has_clklane_stop = 1,
 	.num_clks = 2,
 	.max_freq = 2100,
+	.wait_for_hdr_fifo = 1,
 	.wait_for_reset = 0,
 	.num_bits_resol = 12,
 	/*
@@ -1117,6 +1123,7 @@ static void samsung_dsim_send_to_fifo(struct samsung_dsim *dsi,
 {
 	struct device *dev = dsi->dev;
 	struct mipi_dsi_packet *pkt = &xfer->packet;
+	const struct samsung_dsim_driver_data *driver_data = dsi->driver_data;
 	const u8 *payload = pkt->payload + xfer->tx_done;
 	u16 length = pkt->payload_length - xfer->tx_done;
 	bool first = !xfer->tx_done;
@@ -1157,9 +1164,11 @@ static void samsung_dsim_send_to_fifo(struct samsung_dsim *dsi,
 		return;
 
 	reg = get_unaligned_le32(pkt->header);
-	if (samsung_dsim_wait_for_hdr_fifo(dsi)) {
-		dev_err(dev, "waiting for header FIFO timed out\n");
-		return;
+	if (driver_data->wait_for_hdr_fifo) {
+		if (samsung_dsim_wait_for_hdr_fifo(dsi)) {
+			dev_err(dev, "waiting for header FIFO timed out\n");
+			return;
+		}
 	}
 
 	if (NEQV(xfer->flags & MIPI_DSI_MSG_USE_LPM,

include/drm/bridge/samsung-dsim.h

@@ -61,6 +61,7 @@ struct samsung_dsim_driver_data {
 	unsigned int num_clks;
 	unsigned int min_freq;
 	unsigned int max_freq;
+	unsigned int wait_for_hdr_fifo;
 	unsigned int wait_for_reset;
 	unsigned int num_bits_resol;
 	unsigned int pll_p_offset;