[PATCH] mtd: nand: Sunxi calculate timing cfg
From: Roy Spliet <hidden>
Date: 2015-06-09 11:27:24
Subsystem:
memory technology devices (mtd), nand flash subsystem, the rest · Maintainers:
Miquel Raynal, Richard Weinberger, Vignesh Raghavendra, Linus Torvalds
Values derived from the A83 user manual Signed-off-by: Roy Spliet <redacted> --- drivers/mtd/nand/sunxi_nand.c | 43 +++++++++++++++++++++++++++++++++++++------ 1 file changed, 37 insertions(+), 6 deletions(-)
diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c
index 6f93b29..ec99502 100644
--- a/drivers/mtd/nand/sunxi_nand.c
+++ b/drivers/mtd/nand/sunxi_nand.c@@ -194,7 +194,7 @@ struct sunxi_nand_chip_sel { * * @mode: the sunxi ECC mode field deduced from ECC requirements * @layout: the OOB layout depending on the ECC requirements and the - * selected ECC mode + * ed ECC mode */ struct sunxi_nand_hw_ecc { int mode;
@@ -217,6 +217,7 @@ struct sunxi_nand_chip { struct nand_chip nand; struct mtd_info mtd; unsigned long clk_rate; + u32 timing_cfg; int selected; int nsels; struct sunxi_nand_chip_sel sels[0];
@@ -403,6 +404,7 @@ static void sunxi_nfc_select_chip(struct mtd_info *mtd, int chip) } } + writel(sunxi_nand->timing_cfg, nfc->regs + NFC_REG_TIMING_CFG); writel(ctl, nfc->regs + NFC_REG_CTL); sunxi_nand->selected = chip;
@@ -807,10 +809,28 @@ static int sunxi_nfc_hw_syndrome_ecc_write_page(struct mtd_info *mtd, return 0; } +static const s32 tWB_lut[] = {6, 12, 16, 20, -1}; +static const s32 tRHW_lut[] = {4, 8, 12, 20, -1}; + +static s32 sunxi_nand_lookup_timing(const s32 *lut, u32 period, u32 clk_period) +{ + u32 clks = (period + clk_period - 1) / clk_period; + int i; + + for (i = 0; lut[i] != -1; i++) { + if (clks <= lut[i]) + return i; + } + + /* Return max value */ + return i - 1; +} + static int sunxi_nand_chip_set_timings(struct sunxi_nand_chip *chip, const struct nand_sdr_timings *timings) { u32 min_clk_period = 0; + u32 tWB, tADL, tWHR, tRHW, tCAD; /* T1 <=> tCLS */ if (timings->tCLS_min > min_clk_period)
@@ -872,6 +892,20 @@ static int sunxi_nand_chip_set_timings(struct sunxi_nand_chip *chip, if (timings->tWC_min > (min_clk_period * 2)) min_clk_period = DIV_ROUND_UP(timings->tWC_min, 2); + /* T16 - T19 + tCAD */ + tWB = sunxi_nand_lookup_timing(tWB_lut, timings->tWB_max, + min_clk_period); + tADL = DIV_ROUND_UP(timings->tADL_min, min_clk_period) >> 3; + tWHR = DIV_ROUND_UP(timings->tWHR_min, min_clk_period) >> 3; + tRHW = sunxi_nand_lookup_timing(tRHW_lut, timings->tRHW_min, + min_clk_period); + tCAD = 0x7; + chip->timing_cfg = (tWB & 0x3) | + (tADL & 0x3) << 2 | + (tWHR & 0x3) << 4 | + (tRHW & 0x3) << 6 | + (tCAD & 0x7) << 8; + /* \todo A83 has some more bits for CDQSS, CS, CLHZ, CCS, WC */ /* Convert min_clk_period from picoseconds to nanoseconds */ min_clk_period = DIV_ROUND_UP(min_clk_period, 1000);
@@ -884,8 +918,6 @@ static int sunxi_nand_chip_set_timings(struct sunxi_nand_chip *chip, */ chip->clk_rate = (2 * NSEC_PER_SEC) / min_clk_period; - /* TODO: configure T16-T19 */ - return 0; }
@@ -1168,6 +1200,7 @@ static int sunxi_nand_chip_init(struct device *dev, struct sunxi_nfc *nfc, chip->nsels = nsels; chip->selected = -1; + chip->timing_cfg = 0x7ff; for (i = 0; i < nsels; i++) { ret = of_property_read_u32_index(np, "reg", i, &tmp);
@@ -1377,11 +1410,9 @@ static int sunxi_nfc_probe(struct platform_device *pdev) platform_set_drvdata(pdev, nfc); /* - * TODO: replace these magic values with proper flags as soon as we - * know what they are encoding. + * TODO: replace this magic values with EDO flag */ writel(0x100, nfc->regs + NFC_REG_TIMING_CTL); - writel(0x7ff, nfc->regs + NFC_REG_TIMING_CFG); ret = sunxi_nand_chips_init(dev, nfc); if (ret) {
--
2.4.2
--
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