All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH] mtd: rawnand: arasan: Fix clock rate in NV-DDR
@ 2021-11-27 18:07 Olga Kitaina
  2021-11-29  8:55 ` Miquel Raynal
  0 siblings, 1 reply; 14+ messages in thread
From: Olga Kitaina @ 2021-11-27 18:07 UTC (permalink / raw)
  To: miquel.raynal; +Cc: linux-mtd, Olga Kitaina

According to the Arasan NAND controller spec,
the flash clock rate for SDR must be <= 100 MHz,
while for NV-DDR it must be the same as the rate
of the CLK line for the mode.
The driver previously always set 100 MHz for NV-DDR, which
would result in incorrect behavior for NV-DDR modes 0-4.

The appropriate clock rate can be calculated
from the NV-DDR timing parameters as 1/tCK, or for rates
measured in picoseconds, 10^12 / nand_nvddr_timings->tCK_min.

Signed-off-by: Olga Kitaina <okitain@gmail.com>
---
 drivers/mtd/nand/raw/arasan-nand-controller.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/raw/arasan-nand-controller.c b/drivers/mtd/nand/raw/arasan-nand-controller.c
index 53bd10738418..ed4ee9942441 100644
--- a/drivers/mtd/nand/raw/arasan-nand-controller.c
+++ b/drivers/mtd/nand/raw/arasan-nand-controller.c
@@ -18,6 +18,7 @@
 #include <linux/gpio/consumer.h>
 #include <linux/interrupt.h>
 #include <linux/iopoll.h>
+#include <linux/math64.h>
 #include <linux/module.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
@@ -1043,7 +1044,12 @@ static int anfc_setup_interface(struct nand_chip *chip, int target,
 				 DQS_BUFF_SEL_OUT(dqs_mode);
 	}
 
-	anand->clk = ANFC_XLNX_SDR_DFLT_CORE_CLK;
+	if (nand_interface_is_sdr)
+		anand->clk = ANFC_XLNX_SDR_DFLT_CORE_CLK;
+	else
+		/* ONFI timings are defined in picoseconds */
+		anand->clk = div_u64((u64)NSEC_PER_SEC * 1000,
+				     conf->timings.nvddr.tCK_min);
 
 	/*
 	 * Due to a hardware bug in the ZynqMP SoC, SDR timing modes 0-1 work

base-commit: f53d4c109a666bf1a4883b45d546fba079258717
-- 
2.20.1


______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

^ permalink raw reply related	[flat|nested] 14+ messages in thread

end of thread, other threads:[~2022-01-25 11:19 UTC | newest]

Thread overview: 14+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-11-27 18:07 [PATCH] mtd: rawnand: arasan: Fix clock rate in NV-DDR Olga Kitaina
2021-11-29  8:55 ` Miquel Raynal
2021-11-29 18:06   ` Olga Kitaina
2021-11-29 18:06     ` Olga Kitaina
2021-11-30  7:20     ` Miquel Raynal
2021-11-30  7:20       ` Miquel Raynal
2021-11-30 20:08       ` Olga Kitaina
2021-11-30 20:08         ` Olga Kitaina
2021-12-01  8:09         ` Miquel Raynal
2021-12-01  8:09           ` Miquel Raynal
2021-12-01  8:16           ` Michal Simek
2021-12-01  8:16             ` Michal Simek
2022-01-25 11:16             ` Amit Kumar Kumar Mahapatra
2022-01-25 11:16               ` Amit Kumar Kumar Mahapatra

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.