OMAP: DSS2: DSI: change DSI timeout functions

Using nanoseconds as arguments to functions that set the DSI timeouts was
perhaps not so good idea. The timeouts are based on different DSI clocks,
so the possible range for the timeouts vary greatly depending on the
clocks. Also, the multipliers used with the timeouts cause big gaps in the
timeout range, meaning that the nanosecond based functions could cause the
timeout to be quite far from the intended value.

This patch changes the functions to take the plain tick values with the
multiplier enable/disable bits, and sets the TA/LP_RX/HS_TX timeouts to
maximum. While the timeouts could be much lower, the fact is that when
TA/LP_RX/HS_TX timeout happens, we are in an error situation and not in a
hurry anyway.

STOP_STATE_COUNTER is a different matter, but it is only used at
initialization time, and won't normally affect the performance.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@nokia.com>

1 files changed, 56 insertions, 160 deletions

diff --git a/drivers/video/omap2/dss/dsi.c b/drivers/video/omap2/dss/dsi.c
index 5b6217674559..613796b54f07 100644
--- a/drivers/video/omap2/dss/dsi.c
+++ b/drivers/video/omap2/dss/dsi.c
@@ -2277,212 +2277,108 @@ int dsi_vc_set_max_rx_packet_size(int channel, u16 len)
 }
 EXPORT_SYMBOL(dsi_vc_set_max_rx_packet_size);
 
-static void dsi_set_lp_rx_timeout(unsigned long ns)
+static void dsi_set_lp_rx_timeout(unsigned ticks, bool x4, bool x16)
 {
-	u32 r;
-	unsigned x4, x16;
 	unsigned long fck;
-	unsigned long ticks;
+	unsigned long total_ticks;
+	u32 r;
 
-	/* ticks in DSI_FCK */
+	BUG_ON(ticks > 0x1fff);
 
+	/* ticks in DSI_FCK */
 	fck = dsi_fclk_rate();
-	ticks = (fck / 1000 / 1000) * ns / 1000;
-	x4 = 0;
-	x16 = 0;
-
-	if (ticks > 0x1fff) {
-		ticks = (fck / 1000 / 1000) * ns / 1000 / 4;
-		x4 = 1;
-		x16 = 0;
-	}
-
-	if (ticks > 0x1fff) {
-		ticks = (fck / 1000 / 1000) * ns / 1000 / 16;
-		x4 = 0;
-		x16 = 1;
-	}
-
-	if (ticks > 0x1fff) {
-		ticks = (fck / 1000 / 1000) * ns / 1000 / (4 * 16);
-		x4 = 1;
-		x16 = 1;
-	}
-
-	if (ticks > 0x1fff) {
-		DSSWARN("LP_TX_TO over limit, setting it to max\n");
-		ticks = 0x1fff;
-		x4 = 1;
-		x16 = 1;
-	}
 
 	r = dsi_read_reg(DSI_TIMING2);
 	r = FLD_MOD(r, 1, 15, 15);	/* LP_RX_TO */
-	r = FLD_MOD(r, x16, 14, 14);	/* LP_RX_TO_X16 */
-	r = FLD_MOD(r, x4, 13, 13);	/* LP_RX_TO_X4 */
+	r = FLD_MOD(r, x16 ? 1 : 0, 14, 14);	/* LP_RX_TO_X16 */
+	r = FLD_MOD(r, x4 ? 1 : 0, 13, 13);	/* LP_RX_TO_X4 */
 	r = FLD_MOD(r, ticks, 12, 0);	/* LP_RX_COUNTER */
 	dsi_write_reg(DSI_TIMING2, r);
 
-	DSSDBG("LP_RX_TO %lu ns (%#lx ticks%s%s)\n",
-			(ticks * (x16 ? 16 : 1) * (x4 ? 4 : 1) * 1000) /
-			(fck / 1000 / 1000),
-			ticks, x4 ? " x4" : "", x16 ? " x16" : "");
+	total_ticks = ticks * (x16 ? 16 : 1) * (x4 ? 4 : 1);
+
+	DSSDBG("LP_RX_TO %lu ticks (%#x%s%s) = %lu ns\n",
+			total_ticks,
+			ticks, x4 ? " x4" : "", x16 ? " x16" : "",
+			(total_ticks * 1000) / (fck / 1000 / 1000));
 }
 
-static void dsi_set_ta_timeout(unsigned long ns)
+static void dsi_set_ta_timeout(unsigned ticks, bool x8, bool x16)
 {
-	u32 r;
-	unsigned x8, x16;
 	unsigned long fck;
-	unsigned long ticks;
+	unsigned long total_ticks;
+	u32 r;
+
+	BUG_ON(ticks > 0x1fff);
 
 	/* ticks in DSI_FCK */
 	fck = dsi_fclk_rate();
-	ticks = (fck / 1000 / 1000) * ns / 1000;
-	x8 = 0;
-	x16 = 0;
-
-	if (ticks > 0x1fff) {
-		ticks = (fck / 1000 / 1000) * ns / 1000 / 8;
-		x8 = 1;
-		x16 = 0;
-	}
-
-	if (ticks > 0x1fff) {
-		ticks = (fck / 1000 / 1000) * ns / 1000 / 16;
-		x8 = 0;
-		x16 = 1;
-	}
-
-	if (ticks > 0x1fff) {
-		ticks = (fck / 1000 / 1000) * ns / 1000 / (8 * 16);
-		x8 = 1;
-		x16 = 1;
-	}
-
-	if (ticks > 0x1fff) {
-		DSSWARN("TA_TO over limit, setting it to max\n");
-		ticks = 0x1fff;
-		x8 = 1;
-		x16 = 1;
-	}
 
 	r = dsi_read_reg(DSI_TIMING1);
 	r = FLD_MOD(r, 1, 31, 31);	/* TA_TO */
-	r = FLD_MOD(r, x16, 30, 30);	/* TA_TO_X16 */
-	r = FLD_MOD(r, x8, 29, 29);	/* TA_TO_X8 */
+	r = FLD_MOD(r, x16 ? 1 : 0, 30, 30);	/* TA_TO_X16 */
+	r = FLD_MOD(r, x8 ? 1 : 0, 29, 29);	/* TA_TO_X8 */
 	r = FLD_MOD(r, ticks, 28, 16);	/* TA_TO_COUNTER */
 	dsi_write_reg(DSI_TIMING1, r);
 
-	DSSDBG("TA_TO %lu ns (%#lx ticks%s%s)\n",
-			(ticks * (x16 ? 16 : 1) * (x8 ? 8 : 1) * 1000) /
-			(fck / 1000 / 1000),
-			ticks, x8 ? " x8" : "", x16 ? " x16" : "");
+	total_ticks = ticks * (x16 ? 16 : 1) * (x8 ? 8 : 1);
+
+	DSSDBG("TA_TO %lu ticks (%#x%s%s) = %lu ns\n",
+			total_ticks,
+			ticks, x8 ? " x8" : "", x16 ? " x16" : "",
+			(total_ticks * 1000) / (fck / 1000 / 1000));
 }
 
-static void dsi_set_stop_state_counter(unsigned long ns)
+static void dsi_set_stop_state_counter(unsigned ticks, bool x4, bool x16)
 {
-	u32 r;
-	unsigned x4, x16;
 	unsigned long fck;
-	unsigned long ticks;
+	unsigned long total_ticks;
+	u32 r;
 
-	/* ticks in DSI_FCK */
+	BUG_ON(ticks > 0x1fff);
 
+	/* ticks in DSI_FCK */
 	fck = dsi_fclk_rate();
-	ticks = (fck / 1000 / 1000) * ns / 1000;
-	x4 = 0;
-	x16 = 0;
-
-	if (ticks > 0x1fff) {
-		ticks = (fck / 1000 / 1000) * ns / 1000 / 4;
-		x4 = 1;
-		x16 = 0;
-	}
-
-	if (ticks > 0x1fff) {
-		ticks = (fck / 1000 / 1000) * ns / 1000 / 16;
-		x4 = 0;
-		x16 = 1;
-	}
-
-	if (ticks > 0x1fff) {
-		ticks = (fck / 1000 / 1000) * ns / 1000 / (4 * 16);
-		x4 = 1;
-		x16 = 1;
-	}
-
-	if (ticks > 0x1fff) {
-		DSSWARN("STOP_STATE_COUNTER_IO over limit, "
-				"setting it to max\n");
-		ticks = 0x1fff;
-		x4 = 1;
-		x16 = 1;
-	}
 
 	r = dsi_read_reg(DSI_TIMING1);
 	r = FLD_MOD(r, 1, 15, 15);	/* FORCE_TX_STOP_MODE_IO */
-	r = FLD_MOD(r, x16, 14, 14);	/* STOP_STATE_X16_IO */
-	r = FLD_MOD(r, x4, 13, 13);	/* STOP_STATE_X4_IO */
+	r = FLD_MOD(r, x16 ? 1 : 0, 14, 14);	/* STOP_STATE_X16_IO */
+	r = FLD_MOD(r, x4 ? 1 : 0, 13, 13);	/* STOP_STATE_X4_IO */
 	r = FLD_MOD(r, ticks, 12, 0);	/* STOP_STATE_COUNTER_IO */
 	dsi_write_reg(DSI_TIMING1, r);
 
-	DSSDBG("STOP_STATE_COUNTER %lu ns (%#lx ticks%s%s)\n",
-			(ticks * (x16 ? 16 : 1) * (x4 ? 4 : 1) * 1000) /
-			(fck / 1000 / 1000),
-			ticks, x4 ? " x4" : "", x16 ? " x16" : "");
+	total_ticks = ticks * (x16 ? 16 : 1) * (x4 ? 4 : 1);
+
+	DSSDBG("STOP_STATE_COUNTER %lu ticks (%#x%s%s) = %lu ns\n",
+			total_ticks,
+			ticks, x4 ? " x4" : "", x16 ? " x16" : "",
+			(total_ticks * 1000) / (fck / 1000 / 1000));
 }
 
-static void dsi_set_hs_tx_timeout(unsigned long ns)
+static void dsi_set_hs_tx_timeout(unsigned ticks, bool x4, bool x16)
 {
-	u32 r;
-	unsigned x4, x16;
 	unsigned long fck;
-	unsigned long ticks;
+	unsigned long total_ticks;
+	u32 r;
 
-	/* ticks in TxByteClkHS */
+	BUG_ON(ticks > 0x1fff);
 
+	/* ticks in TxByteClkHS */
 	fck = dsi_get_txbyteclkhs();
-	ticks = (fck / 1000 / 1000) * ns / 1000;
-	x4 = 0;
-	x16 = 0;
-
-	if (ticks > 0x1fff) {
-		ticks = (fck / 1000 / 1000) * ns / 1000 / 4;
-		x4 = 1;
-		x16 = 0;
-	}
-
-	if (ticks > 0x1fff) {
-		ticks = (fck / 1000 / 1000) * ns / 1000 / 16;
-		x4 = 0;
-		x16 = 1;
-	}
-
-	if (ticks > 0x1fff) {
-		ticks = (fck / 1000 / 1000) * ns / 1000 / (4 * 16);
-		x4 = 1;
-		x16 = 1;
-	}
-
-	if (ticks > 0x1fff) {
-		DSSWARN("HS_TX_TO over limit, setting it to max\n");
-		ticks = 0x1fff;
-		x4 = 1;
-		x16 = 1;
-	}
 
 	r = dsi_read_reg(DSI_TIMING2);
 	r = FLD_MOD(r, 1, 31, 31);	/* HS_TX_TO */
-	r = FLD_MOD(r, x16, 30, 30);	/* HS_TX_TO_X16 */
-	r = FLD_MOD(r, x4, 29, 29);	/* HS_TX_TO_X8 (4 really) */
+	r = FLD_MOD(r, x16 ? 1 : 0, 30, 30);	/* HS_TX_TO_X16 */
+	r = FLD_MOD(r, x4 ? 1 : 0, 29, 29);	/* HS_TX_TO_X8 (4 really) */
 	r = FLD_MOD(r, ticks, 28, 16);	/* HS_TX_TO_COUNTER */
 	dsi_write_reg(DSI_TIMING2, r);
 
-	DSSDBG("HS_TX_TO %lu ns (%#lx ticks%s%s)\n",
-			(ticks * (x16 ? 16 : 1) * (x4 ? 4 : 1) * 1000) /
-			(fck / 1000 / 1000),
-			ticks, x4 ? " x4" : "", x16 ? " x16" : "");
+	total_ticks = ticks * (x16 ? 16 : 1) * (x4 ? 4 : 1);
+
+	DSSDBG("HS_TX_TO %lu ticks (%#x%s%s) = %lu ns\n",
+			total_ticks,
+			ticks, x4 ? " x4" : "", x16 ? " x16" : "",
+			(total_ticks * 1000) / (fck / 1000 / 1000));
 }
 static int dsi_proto_config(struct omap_dss_device *dssdev)
 {
@@ -2500,10 +2396,10 @@ static int dsi_proto_config(struct omap_dss_device *dssdev)
 			DSI_FIFO_SIZE_32);
 
 	/* XXX what values for the timeouts? */
-	dsi_set_stop_state_counter(1000);
-	dsi_set_ta_timeout(6400000);
-	dsi_set_lp_rx_timeout(48000);
-	dsi_set_hs_tx_timeout(8000000);
+	dsi_set_stop_state_counter(0x1000, false, false);
+	dsi_set_ta_timeout(0x1fff, true, true);
+	dsi_set_lp_rx_timeout(0x1fff, true, true);
+	dsi_set_hs_tx_timeout(0x1fff, true, true);
 
 	switch (dssdev->ctrl.pixel_size) {
 	case 16: