From 9c618292dba6aa9b82e8a2e4e6fe70f54bd87a81 Mon Sep 17 00:00:00 2001 From: Roy Spliet Date: Fri, 26 Jun 2015 11:00:10 +0200 Subject: [PATCH] mtd: nand: sunxi: Replace failsafe timing cfg with calculated value The TIMING_CFG register was previously statically set to a magic value (extracted from Allwinner's BSP) when initializing the NAND controller. Now that we have more details about the TIMING_CFG register layout (extracted from the A83 user manual) we can dynamically calculate the appropriate value for each NAND chip and set it when selecting the chip. Signed-off-by: Roy Spliet Acked-by: Boris Brezillon Signed-off-by: Brian Norris --- drivers/mtd/nand/sunxi_nand.c | 73 ++++++++++++++++++++++++++++++++--- 1 file changed, 68 insertions(+), 5 deletions(-) diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c index 6f93b2990d25..663e3314bb83 100644 --- a/drivers/mtd/nand/sunxi_nand.c +++ b/drivers/mtd/nand/sunxi_nand.c @@ -99,6 +99,12 @@ NFC_CMD_INT_ENABLE | \ NFC_DMA_INT_ENABLE) +/* define NFC_TIMING_CFG register layout */ +#define NFC_TIMING_CFG(tWB, tADL, tWHR, tRHW, tCAD) \ + (((tWB) & 0x3) | (((tADL) & 0x3) << 2) | \ + (((tWHR) & 0x3) << 4) | (((tRHW) & 0x3) << 6) | \ + (((tCAD) & 0x7) << 8)) + /* define bit use in NFC_CMD */ #define NFC_CMD_LOW_BYTE GENMASK(7, 0) #define NFC_CMD_HIGH_BYTE GENMASK(15, 8) @@ -208,6 +214,7 @@ struct sunxi_nand_hw_ecc { * @nand: base NAND chip structure * @mtd: base MTD structure * @clk_rate: clk_rate required for this NAND chip + * @timing_cfg TIMING_CFG register value for this NAND chip * @selected: current active CS * @nsels: number of CS lines required by the NAND chip * @sels: array of CS lines descriptions @@ -217,6 +224,7 @@ 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 +411,7 @@ 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 +816,33 @@ static int sunxi_nfc_hw_syndrome_ecc_write_page(struct mtd_info *mtd, return 0; } +static const s32 tWB_lut[] = {6, 12, 16, 20}; +static const s32 tRHW_lut[] = {4, 8, 12, 20}; + +static int _sunxi_nand_lookup_timing(const s32 *lut, int lut_size, u32 duration, + u32 clk_period) +{ + u32 clk_cycles = DIV_ROUND_UP(duration, clk_period); + int i; + + for (i = 0; i < lut_size; i++) { + if (clk_cycles <= lut[i]) + return i; + } + + /* Doesn't fit */ + return -EINVAL; +} + +#define sunxi_nand_lookup_timing(l, p, c) \ + _sunxi_nand_lookup_timing(l, ARRAY_SIZE(l), p, c) + static int sunxi_nand_chip_set_timings(struct sunxi_nand_chip *chip, const struct nand_sdr_timings *timings) { + struct sunxi_nfc *nfc = to_sunxi_nfc(chip->nand.controller); u32 min_clk_period = 0; + s32 tWB, tADL, tWHR, tRHW, tCAD; /* T1 <=> tCLS */ if (timings->tCLS_min > min_clk_period) @@ -872,6 +904,41 @@ 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); + if (tWB < 0) { + dev_err(nfc->dev, "unsupported tWB\n"); + return tWB; + } + + tADL = DIV_ROUND_UP(timings->tADL_min, min_clk_period) >> 3; + if (tADL > 3) { + dev_err(nfc->dev, "unsupported tADL\n"); + return -EINVAL; + } + + tWHR = DIV_ROUND_UP(timings->tWHR_min, min_clk_period) >> 3; + if (tWHR > 3) { + dev_err(nfc->dev, "unsupported tWHR\n"); + return -EINVAL; + } + + tRHW = sunxi_nand_lookup_timing(tRHW_lut, timings->tRHW_min, + min_clk_period); + if (tRHW < 0) { + dev_err(nfc->dev, "unsupported tRHW\n"); + return tRHW; + } + + /* + * TODO: according to ONFI specs this value only applies for DDR NAND, + * but Allwinner seems to set this to 0x7. Mimic them for now. + */ + tCAD = 0x7; + + /* TODO: A83 has some more bits for CDQSS, CS, CLHZ, CCS, WC */ + chip->timing_cfg = NFC_TIMING_CFG(tWB, tADL, tWHR, tRHW, tCAD); /* Convert min_clk_period from picoseconds to nanoseconds */ min_clk_period = DIV_ROUND_UP(min_clk_period, 1000); @@ -884,8 +951,6 @@ 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; } @@ -1377,11 +1442,9 @@ 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 value 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) { -- 2.39.5