[PATCH v2 2/5] mtd: nand: add NVIDIA Tegra NAND Flash controller driver
Lucas Stach
dev at lynxeye.de
Mon Apr 13 12:22:54 PDT 2015
Hi Stefan,
thanks for the review.
Am Freitag, den 10.04.2015, 10:46 +0200 schrieb Stefan Agner:
> Hi Lucas,
>
> Thanks for working on that. Some minor comments below...
>
> On 2015-04-08 21:46, Lucas Stach wrote:
> > Add support for the NAND flash controller found on NVIDIA
> > Tegra 2/3 SoCs.
> >
> > Signed-off-by: Thierry Reding <thierry.reding at avionic-design.de>
> > Signed-off-by: Lucas Stach <dev at lynxeye.de>
> > ---
> > v2:
> > - remove Tegra 3 compatible
> > - remove useless part_probes
> > - don't store irq number
> > - use gpiod API instead of deprecated of_gpios
> > - don't store reset
> > - correct TIMING_TCS mask
> > - simplify irq handler
> > - correct timing calculations
> > - don't store buswidth
> > - drop compile test
> > - correct ECC handling
> > ---
> > MAINTAINERS | 6 +
> > drivers/mtd/nand/Kconfig | 6 +
> > drivers/mtd/nand/Makefile | 1 +
> > drivers/mtd/nand/tegra_nand.c | 786 ++++++++++++++++++++++++++++++++++++++++++
> > 4 files changed, 799 insertions(+)
> > create mode 100644 drivers/mtd/nand/tegra_nand.c
> >
> [...]
> > +static struct nand_ecclayout tegra_nand_oob_16 = {
> > + .eccbytes = 4,
> > + .eccpos = { 3, 4, 5, 6 },
> > + .oobfree = {
> > + { .offset = 7, . length = 8 }
> > + }
> > +};
> > +
> > +static struct nand_ecclayout tegra_nand_oob_64 = {
> > + .eccbytes = 36,
> > + .eccpos = {
> > + 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
> > + 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34,
> > + 35, 36, 37, 38, 39
> > + },
>
> The amount of eccbytes vs. length of eccpos do not match...
>
> > + .oobfree = {
> > + { .offset = 40, .length = 24 }
> > + }
> > +};
> > +
> > +static struct nand_ecclayout tegra_nand_oob_128 = {
> > + .eccbytes = 72,
> > + .eccpos = {
> > + 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
> > + 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34,
> > + 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50,
> > + 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66,
> > + 67, 68, 69, 70, 71, 72, 73, 74, 75
> > + },
>
> Here...
>
> > + .oobfree = {
> > + { .offset = 76, .length = 52 }
> > + }
> > +};
> > +
> > +static struct nand_ecclayout tegra_nand_oob_224 = {
> > + .eccbytes = 144,
> > + .eccpos = {
> > + 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
> > + 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26,
> > + 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
> > + 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50,
> > + 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62,
> > + 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74,
> > + 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86,
> > + 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98,
> > + 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110,
> > + 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122,
> > + 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134,
> > + 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146,
> > + 147
> > + },
>
> ... and here too.
>
Urgh, actually they are all wrong, as the ECC starts at byte 4, not
3. :/ Thanks for the hint.
> [...]
> > +static int tegra_nand_probe(struct platform_device *pdev)
> > +{
> > + struct reset_control *rst;
> > + struct tegra_nand *nand;
> > + struct nand_chip *chip;
> > + struct mtd_info *mtd;
> > + struct resource *res;
> > + unsigned long value;
> > + int irq, buswidth, err = 0;
> > +
> > + nand = devm_kzalloc(&pdev->dev, sizeof(*nand), GFP_KERNEL);
> > + if (!nand)
> > + return -ENOMEM;
> > +
> > + nand->dev = &pdev->dev;
> > +
> > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > + nand->regs = devm_ioremap_resource(&pdev->dev, res);
> > + if (IS_ERR(nand->regs))
> > + return PTR_ERR(nand->regs);
> > +
> > + irq = platform_get_irq(pdev, 0);
> > + err = devm_request_irq(&pdev->dev, irq, tegra_nand_irq, 0,
> > + dev_name(&pdev->dev), nand);
> > + if (err)
> > + return err;
> > +
> > + rst = devm_reset_control_get(&pdev->dev, "nand");
> > + if (IS_ERR(rst))
> > + return PTR_ERR(rst);
> > +
> > + nand->clk = devm_clk_get(&pdev->dev, "nand");
> > + if (IS_ERR(nand->clk))
> > + return PTR_ERR(nand->clk);
> > +
> > + nand->wp_gpio = gpiod_get_optional(&pdev->dev, "nvidia,wp-gpios",
> > + GPIOD_OUT_HIGH);
> > + if (IS_ERR(nand->wp_gpio))
> > + return PTR_ERR(nand->wp_gpio);
> > +
> > + buswidth = of_get_nand_bus_width(pdev->dev.of_node);
> > + if (buswidth < 0)
> > + return buswidth;
> > +
> > + err = clk_prepare_enable(nand->clk);
> > + if (err)
> > + return err;
> > +
> > + reset_control_assert(rst);
> > + udelay(2);
> > + reset_control_deassert(rst);
> > +
> > + value = HWSTATUS_RDSTATUS_MASK(1) | HWSTATUS_RDSTATUS_VALUE(0) |
> > + HWSTATUS_RBSY_MASK(NAND_STATUS_READY) |
> > + HWSTATUS_RBSY_VALUE(NAND_STATUS_READY);
> > + writel(NAND_CMD_STATUS, nand->regs + HWSTATUS_CMD);
> > + writel(value, nand->regs + HWSTATUS_MASK);
> > +
> > + init_completion(&nand->command_complete);
> > + init_completion(&nand->dma_complete);
> > +
> > + mtd = &nand->mtd;
> > + mtd->name = dev_name(&pdev->dev);
> > + mtd->owner = THIS_MODULE;
> > + mtd->priv = &nand->chip;
> > +
> > + mtd->type = MTD_NANDFLASH;
> > + mtd->flags = MTD_CAP_NANDFLASH;
>
> This get filled by nand_scan_tail anyway, any reason to have it here
> too?
>
No, not really. Probably just cargo-culting. I'll remove this.
> Other than that, looks solid to me.
>
> Reviewed-by: Stefan Agner <stefan at agner.ch>
>
I'll wait a bit more before posting a v3, to give other people a chance
to look at this.
Thanks,
Lucas
More information about the linux-mtd
mailing list