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mtd: nand: sunxi: Set serial access mode correctly

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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>
This commit is contained in:
Roy Spliet 2015-06-26 11:00:11 +02:00 committed by Brian Norris
parent 9c618292db
commit d052e508a4
1 changed files with 12 additions and 5 deletions
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17
drivers/mtd/nand/sunxi_nand.c
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@ -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");