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authorRoy Spliet <r.spliet@ultimaker.com>2015-06-26 12:00:11 +0300
committerBrian Norris <computersforpeace@gmail.com>2015-07-20 20:45:53 +0300
commitd052e508a4069f0711ea68156f4b1565bf14c41c (patch)
treeac298d86ef0e68d48ddff22982c8835b0327560b /drivers/mtd
parent9c618292dba6aa9b82e8a2e4e6fe70f54bd87a81 (diff)
downloadlinux-d052e508a4069f0711ea68156f4b1565bf14c41c.tar.xz
mtd: nand: sunxi: Set serial access mode correctly
Replaces the hard coded "always use EDO" policy with that prescribed by the ONFI 3.1 specification that EDO mode should always be used if tRC is below 30ns. Signed-off-by: Roy Spliet <r.spliet@ultimaker.com> Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/nand/sunxi_nand.c17
1 files changed, 12 insertions, 5 deletions
diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c
index 663e3314bb83..f97a58d6aae1 100644
--- a/drivers/mtd/nand/sunxi_nand.c
+++ b/drivers/mtd/nand/sunxi_nand.c
@@ -99,6 +99,9 @@
NFC_CMD_INT_ENABLE | \
NFC_DMA_INT_ENABLE)
+/* define bit use in NFC_TIMING_CTL */
+#define NFC_TIMING_CTL_EDO BIT(8)
+
/* define NFC_TIMING_CFG register layout */
#define NFC_TIMING_CFG(tWB, tADL, tWHR, tRHW, tCAD) \
(((tWB) & 0x3) | (((tADL) & 0x3) << 2) | \
@@ -225,6 +228,7 @@ struct sunxi_nand_chip {
struct mtd_info mtd;
unsigned long clk_rate;
u32 timing_cfg;
+ u32 timing_ctl;
int selected;
int nsels;
struct sunxi_nand_chip_sel sels[0];
@@ -411,6 +415,7 @@ static void sunxi_nfc_select_chip(struct mtd_info *mtd, int chip)
}
}
+ writel(sunxi_nand->timing_ctl, nfc->regs + NFC_REG_TIMING_CTL);
writel(sunxi_nand->timing_cfg, nfc->regs + NFC_REG_TIMING_CFG);
writel(ctl, nfc->regs + NFC_REG_CTL);
@@ -940,6 +945,13 @@ static int sunxi_nand_chip_set_timings(struct sunxi_nand_chip *chip,
/* TODO: A83 has some more bits for CDQSS, CS, CLHZ, CCS, WC */
chip->timing_cfg = NFC_TIMING_CFG(tWB, tADL, tWHR, tRHW, tCAD);
+ /*
+ * ONFI specification 3.1, paragraph 4.15.2 dictates that EDO data
+ * output cycle timings shall be used if the host drives tRC less than
+ * 30 ns.
+ */
+ chip->timing_ctl = (timings->tRC_min < 30000) ? NFC_TIMING_CTL_EDO : 0;
+
/* Convert min_clk_period from picoseconds to nanoseconds */
min_clk_period = DIV_ROUND_UP(min_clk_period, 1000);
@@ -1441,11 +1453,6 @@ static int sunxi_nfc_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, nfc);
- /*
- * TODO: replace this magic value with EDO flag
- */
- writel(0x100, nfc->regs + NFC_REG_TIMING_CTL);
-
ret = sunxi_nand_chips_init(dev, nfc);
if (ret) {
dev_err(dev, "failed to init nand chips\n");