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[04/16] mtd: nand: sunxi: adapt clk_rate to tWB, tADL, tWHR and tRHW timings

Message ID 1457367513-26069-5-git-send-email-boris.brezillon@free-electrons.com (mailing list archive)
State New, archived
Headers show

Commit Message

Boris BREZILLON March 7, 2016, 4:18 p.m. UTC 
Adapt the NAND controller clk rate to the tWB, tADL, tWHR and tRHW
timings instead of returning an error when the maximum clk divisor is
not big enough to provide an appropriate timing.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
 drivers/mtd/nand/sunxi_nand.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)
diff mbox

Patch

diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c
index a270720..2914785 100644
--- a/drivers/mtd/nand/sunxi_nand.c
+++ b/drivers/mtd/nand/sunxi_nand.c
@@ -1164,6 +1164,18 @@  static int sunxi_nand_chip_set_timings(struct sunxi_nand_chip *chip,
 		min_clk_period = DIV_ROUND_UP(timings->tWC_min, 2);
 
 	/* T16 - T19 + tCAD */
+	if (timings->tWB_max > (min_clk_period * 20))
+		min_clk_period = DIV_ROUND_UP(timings->tWB_max, 20);
+
+	if (timings->tADL_min > (min_clk_period * 32))
+		min_clk_period = DIV_ROUND_UP(timings->tADL_min, 32);
+
+	if (timings->tWHR_min > (min_clk_period * 32))
+		min_clk_period = DIV_ROUND_UP(timings->tWHR_min, 32);
+
+	if (timings->tRHW_min > (min_clk_period * 20))
+		min_clk_period = DIV_ROUND_UP(timings->tRHW_min, 20);
+
 	tWB  = sunxi_nand_lookup_timing(tWB_lut, timings->tWB_max,
 					min_clk_period);
 	if (tWB < 0) {