Re: [PATCH 3/4] ARM: dts: da850-lcdk: Add NAND to DT

From: Karl Beldan
Date: Wed Aug 10 2016 - 14:49:30 EST


On Tue, Aug 09, 2016 at 05:15:17PM +0000, Karl Beldan wrote:
> This adds DT support for the NAND connected to the SoC AEMIF.
> The parameters (timings, ecc) are the same as what the board ships with
> (default AEMIF timings, 1bit ECC) and improvements will be handled in
> due course.
> This passed elementary tests hashing a 20MB file on top of ubifs on my
> LCDK.
>
> Signed-off-by: Karl Beldan <kbeldan@xxxxxxxxxxxx>
> ---
> arch/arm/boot/dts/da850-lcdk.dts | 108 +++++++++++++++++++++++++++++++++++++++
> 1 file changed, 108 insertions(+)
>
> diff --git a/arch/arm/boot/dts/da850-lcdk.dts b/arch/arm/boot/dts/da850-lcdk.dts
> index dbcca0b..033380b 100644
> --- a/arch/arm/boot/dts/da850-lcdk.dts
> +++ b/arch/arm/boot/dts/da850-lcdk.dts
> @@ -27,6 +27,27 @@
>
> &pmx_core {
> status = "okay";
> +
> + nand_pins: nand_pins {
> + pinctrl-single,bits = <
> + /* EMA_WAIT[0], EMA_OE, EMA_WE, EMA_CS[3] */
> + 0x1c 0x10110010 0xf0ff00f0
> + /*
> + * EMA_D[0], EMA_D[1], EMA_D[2],
> + * EMA_D[3], EMA_D[4], EMA_D[5],
> + * EMA_D[6], EMA_D[7]
> + */
> + 0x24 0x11111111 0xffffffff
> + /*
> + * EMA_D[8], EMA_D[9], EMA_D[10],
> + * EMA_D[11], EMA_D[12], EMA_D[13],
> + * EMA_D[14], EMA_D[15]
> + */
> + 0x20 0x11111111 0xffffffff
> + /* EMA_A[1], EMA_A[2] */
> + 0x30 0x01100000 0x0ff00000
> + >;
> + };
> };
>
> &serial2 {
> @@ -68,3 +89,90 @@
> cd-gpios = <&gpio 64 GPIO_ACTIVE_HIGH>;
> status = "okay";
> };
> +
> +&aemif {
> + pinctrl-names = "default";
> + pinctrl-0 = <&nand_pins>;
> + status = "ok";
> + cs2 {
Typo, should be cs3.

Karl
> + #address-cells = <2>;
> + #size-cells = <1>;
> + clock-ranges;
> + ranges;
> +
> + ti,cs-chipselect = <2>;
> +
> + nand@2000000,0 {
> + compatible = "ti,davinci-nand";
> + #address-cells = <1>;
> + #size-cells = <1>;
> + reg = <0 0x02000000 0x02000000
> + 1 0x00000000 0x00008000>;
> +
> + ti,davinci-chipselect = <1>;
> + ti,davinci-mask-ale = <0>;
> + ti,davinci-mask-cle = <0>;
> + ti,davinci-mask-chipsel = <0>;
> +
> + /*
> + * nand_ecc_strength_good will emit a warning
> + * but the LCDK ships with these settings [1].
> + * Also HW 4bits ECC with 16bits NAND seems to
> + * require some attention.
> + *
> + * ATM nand_davinci_probe handling of nand-ecc-*
> + * is broken, e.g.
> + * chip.ecc.strength = pdata->ecc_bits occurs after
> + * scan_ident(), otherwise I would have used:
> + * nand-ecc-mode = "hw";
> + * nand-ecc-strength = <1>;
> + * nand-ecc-step-size = <512>;
> + */
> + ti,davinci-ecc-mode = "hw";
> + ti,davinci-ecc-bits = <1>;
> +
> + nand-bus-width= <16>;
> + nand-on-flash-bbt;
> +
> + /*
> + * LCDK original partitions:
> + * 0x000000000000-0x000000020000 : "u-boot env"
> + * 0x000000020000-0x0000000a0000 : "u-boot"
> + * 0x0000000a0000-0x0000002a0000 : "kernel"
> + * 0x0000002a0000-0x000020000000 : "filesystem"
> + *
> + * The 1st NAND block being guaranted to be valid w/o ECC (> 1k cycles),
> + * it makes a perfect candidate as an SPL for the BootROM to jump to.
> + * However the OMAP-L132/L138 Bootloader doc SPRAB41E reads:
> + * "To boot from NAND Flash, the AIS should be written to NAND block 1
> + * (NAND block 0 is not used by default)", which matches the LCDK
> + * original partitioning.
> + * Also, the LCDK ships with only the u-boot partition provisioned and
> + * boots on it in its default configuration while using the MMC for the
> + * kernel and rootfs, so preserve that one as is for now.
> + * [1]: Ensuring for example that U-Boot LCDK SPL can handle it properly
> + * and a proper boot chain ROM->SPL->U-Boot->Linux wrt ECC, would allow
> + * for a better partitioning.
> + */
> + partitions {
> + compatible = "fixed-partitions";
> + #address-cells = <1>;
> + #size-cells = <1>;
> +
> + partition@0 {
> + label = "u-boot env";
> + reg = <0 0x020000>;
> + };
> + partition@0x020000 {
> + /* The LCDK defaults to booting from this partition */
> + label = "u-boot";
> + reg = <0x020000 0x080000>;
> + };
> + partition@0x0a0000 {
> + label = "space";
> + reg = <0x0a0000 0>;
> + };
> + };
> + };
> + };
> +};
> --
> 2.9.2
>