[PATCH v2 1/2] mtd: rawnand: arasan: Update NAND bus clock instead of system clock

[Amit Kumar Mahapatra <amit.kumar-mahapatra@xilinx.com>]

In current implementation the Arasan NAND driver is updating the
system clock(i.e., anand->clk) in accordance to the timing modes
(i.e., SDR or NVDDR). But as per the Arasan NAND controller spec the
flash clock or the NAND bus clock(i.e., nfc->bus_clk), need to be
updated instead. This patch keeps the system clock unchanged and updates
the NAND bus clock as per the timing modes.

Fixes: 197b88fecc50 ("mtd: rawnand: arasan: Add new Arasan NAND controller")
Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@xilinx.com>
---
 drivers/mtd/nand/raw/arasan-nand-controller.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/nand/raw/arasan-nand-controller.c b/drivers/mtd/nand/raw/arasan-nand-controller.c
index 53bd10738418..4f6da82dd2b1 100644
--- a/drivers/mtd/nand/raw/arasan-nand-controller.c
+++ b/drivers/mtd/nand/raw/arasan-nand-controller.c
@@ -968,6 +968,7 @@ static int anfc_setup_interface(struct nand_chip *chip, int target,
 	const struct nand_sdr_timings *sdr;
 	const struct nand_nvddr_timings *nvddr;
 	unsigned int tccs_min, dqs_mode, fast_tcad;
+	int ret;
 
 	if (nand_interface_is_nvddr(conf)) {
 		nvddr = nand_get_nvddr_timings(conf);
@@ -1043,7 +1044,11 @@ 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;
+	ret = clk_set_rate(nfc->bus_clk, ANFC_XLNX_SDR_DFLT_CORE_CLK);
+	if (ret) {
+		dev_err(nfc->dev, "Failed to change bus clock rate\n");
+		return ret;
+	}
 
 	/*
 	 * Due to a hardware bug in the ZynqMP SoC, SDR timing modes 0-1 work
@@ -1052,8 +1057,13 @@ static int anfc_setup_interface(struct nand_chip *chip, int target,
 	 * 80MHz when using SDR modes 2-5 with this SoC.
 	 */
 	if (of_device_is_compatible(np, "xlnx,zynqmp-nand-controller") &&
-	    nand_interface_is_sdr(conf) && conf->timings.mode >= 2)
-		anand->clk = ANFC_XLNX_SDR_HS_CORE_CLK;
+	    nand_interface_is_sdr(conf) && conf->timings.mode >= 2) {
+		ret = clk_set_rate(nfc->bus_clk, ANFC_XLNX_SDR_HS_CORE_CLK);
+		if (ret) {
+			dev_err(nfc->dev, "Failed to change bus clock rate\n");
+			return ret;
+		}
+	}
 
 	return 0;
 }
-- 
2.17.1