| Message ID | 1433924948-19288-2-git-send-email-r.spliet@ultimaker.com |
|---|---|
| State | Superseded |
| Headers | show |
On Wed, 10 Jun 2015 10:29:08 +0200 Roy Spliet <r.spliet@ultimaker.com> wrote: > 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> > --- > drivers/mtd/nand/sunxi_nand.c | 21 +++++++++++++++------ > 1 file changed, 15 insertions(+), 6 deletions(-) > > diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c > index 68090b7..d98e98c 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 bit use in NFC_TIMING_CFG */ > #define NFC_TIMING_CFG(tWB, tADL, tWHR, tRHW, tCAD) \ > ((tWB) & 0x3) | (((tADL) & 0x3) << 2) | \ > @@ -226,6 +229,7 @@ struct sunxi_nand_chip { > struct mtd_info mtd; > unsigned long clk_rate; > u32 timing_cfg; > + int serial_mode_edo; How about directly storing the timing_ctl value (declaring an unsigned long timing_ctl field) ? This way, if we need to set other fields in the same register we won't have to add new fields to the structure. > int selected; > int nsels; > struct sunxi_nand_chip_sel sels[0]; > @@ -380,7 +384,7 @@ static void sunxi_nfc_select_chip(struct mtd_info *mtd, int chip) > struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand); > struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller); > struct sunxi_nand_chip_sel *sel; > - u32 ctl; > + u32 ctl, timing_ctl; > > if (chip > 0 && chip >= sunxi_nand->nsels) > return; > @@ -412,6 +416,9 @@ static void sunxi_nfc_select_chip(struct mtd_info *mtd, int chip) > } > } > > + timing_ctl = sunxi_nand->serial_mode_edo ? NFC_TIMING_CTL_EDO : 0; > + > + writel(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); > > @@ -937,6 +944,13 @@ 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->serial_mode_edo = (timings->tRC_min < 30000); > + Oh, that's good to know. Thanks, Boris
diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c index 68090b7..d98e98c 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 bit use in NFC_TIMING_CFG */ #define NFC_TIMING_CFG(tWB, tADL, tWHR, tRHW, tCAD) \ ((tWB) & 0x3) | (((tADL) & 0x3) << 2) | \ @@ -226,6 +229,7 @@ struct sunxi_nand_chip { struct mtd_info mtd; unsigned long clk_rate; u32 timing_cfg; + int serial_mode_edo; int selected; int nsels; struct sunxi_nand_chip_sel sels[0]; @@ -380,7 +384,7 @@ static void sunxi_nfc_select_chip(struct mtd_info *mtd, int chip) struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand); struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller); struct sunxi_nand_chip_sel *sel; - u32 ctl; + u32 ctl, timing_ctl; if (chip > 0 && chip >= sunxi_nand->nsels) return; @@ -412,6 +416,9 @@ static void sunxi_nfc_select_chip(struct mtd_info *mtd, int chip) } } + timing_ctl = sunxi_nand->serial_mode_edo ? NFC_TIMING_CTL_EDO : 0; + + writel(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); @@ -937,6 +944,13 @@ 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->serial_mode_edo = (timings->tRC_min < 30000); + /* Convert min_clk_period from picoseconds to nanoseconds */ min_clk_period = DIV_ROUND_UP(min_clk_period, 1000); @@ -1439,11 +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");
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> --- drivers/mtd/nand/sunxi_nand.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-)