mtd: nand: sunxi: adapt clk_rate to tWB, tADL, tWHR and tRHW timings

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>
This commit is contained in:
Boris Brezillon 2015-11-11 22:30:30 +01:00
parent 2d43457f79
commit 5abcd95d8c
1 changed files with 12 additions and 0 deletions

View File

@ -1163,6 +1163,18 @@ 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) {