[PATCH u-boot-dm + u-boot-spi v2 0/7] Support SPI NORs and OF partitions in `mtd list`

[Marek Behun]

On Wed, 10 Feb 2021 14:48:23 +0100
Patrice CHOTARD <patrice.chotard at foss.st.com> wrote:

> +Patrick
> 
> Hi All
> 
> I have tested this series on stm32mp1-ev1 board which embeds 1 nand and 2 identical spi-nor. 
> spi-nor DT node is the following:
> 
> &qspi {
> 	pinctrl-names = "default", "sleep";
> 	pinctrl-0 = <&qspi_clk_pins_a &qspi_bk1_pins_a &qspi_bk2_pins_a>;
> 	pinctrl-1 = <&qspi_clk_sleep_pins_a &qspi_bk1_sleep_pins_a &qspi_bk2_sleep_pins_a>;
> 	reg = <0x58003000 0x1000>, <0x70000000 0x4000000>;
> 	#address-cells = <1>;
> 	#size-cells = <0>;
> 	status = "okay";
> 
> 	flash0: mx66l51235l at 0 {
> 		compatible = "jedec,spi-nor";
> 		reg = <0>;
> 		spi-rx-bus-width = <4>;
> 		spi-max-frequency = <108000000>;
> 		#address-cells = <1>;
> 		#size-cells = <1>;
> 	};
> 
> 	flash1: mx66l51235l at 1 {
> 		compatible = "jedec,spi-nor";
> 		reg = <1>;
> 		spi-rx-bus-width = <4>;
> 		spi-max-frequency = <108000000>;
> 		#address-cells = <1>;
> 		#size-cells = <1>;
> 	};
> };
> 
> As is, this series is not able to differentiate the both identical spi-nor using the MTD framework. 
> Both spi-nor have the same name "mx66l51235l" as shown below, and usage of mtd command is not possible to reach
> both spi-nor:
> 
> STM32MP> mtd list  
> List of MTD devices:
> * nand0
>   - type: NAND flash
>   - block size: 0x40000 bytes
>   - min I/O: 0x1000 bytes
>   - OOB size: 224 bytes
>   - OOB available: 118 bytes
>   - ECC strength: 8 bits
>   - ECC step size: 512 bytes
>   - bitflip threshold: 6 bits
>   - 0x000000000000-0x000040000000 : "nand0"
> * mx66l51235l
>   - device: mx66l51235l at 0
>   - parent: spi at 58003000
>   - driver: jedec_spi_nor
>   - type: NOR flash
>   - block size: 0x10000 bytes
>   - min I/O: 0x1 bytes
>   - 0x000000000000-0x000004000000 : "mx66l51235l"
> * mx66l51235l
>   - device: mx66l51235l at 1
>   - parent: spi at 58003000
>   - driver: jedec_spi_nor
>   - type: NOR flash
>   - block size: 0x10000 bytes
>   - min I/O: 0x1 bytes
>   - 0x000000000000-0x000004000000 : "mx66l51235l"
> 
> The following patch fix it :
> 
> @@ -2528,11 +2528,11 @@ int spi_nor_scan(struct spi_nor *nor)
>  	ret = spi_nor_init_params(nor, info, &params);
>  	if (ret)
>  		return ret;
>  
>  	if (!mtd->name)
> -		mtd->name = info->name;
> +		mtd->name = (char *)nor->dev->name;
>  	mtd->dev = nor->dev;
>  	mtd->priv = nor;
>  	mtd->type = MTD_NORFLASH;
>  	mtd->writesize = 1;
>  	mtd->flags = MTD_CAP_NORFLASH;
> 
> 
> 
> Now it looks like :
> 
> STM32MP> mtd list  
> List of MTD devices:
> * nand0
>   - type: NAND flash
>   - block size: 0x40000 bytes
>   - min I/O: 0x1000 bytes
>   - OOB size: 224 bytes
>   - OOB available: 118 bytes
>   - ECC strength: 8 bits
>   - ECC step size: 512 bytes
>   - bitflip threshold: 6 bits
>   - 0x000000000000-0x000040000000 : "nand0"
> * mx66l51235l at 0
>   - device: mx66l51235l at 0
>   - parent: spi at 58003000
>   - driver: jedec_spi_nor
>   - type: NOR flash
>   - block size: 0x10000 bytes
>   - min I/O: 0x1 bytes
>   - 0x000000000000-0x000004000000 : "mx66l51235l at 0"
> * mx66l51235l at 1
>   - device: mx66l51235l at 1
>   - parent: spi at 58003000
>   - driver: jedec_spi_nor
>   - type: NOR flash
>   - block size: 0x10000 bytes
>   - min I/O: 0x1 bytes
>   - 0x000000000000-0x000004000000 : "mx66l51235l at 1"
> STM32MP>   
> 
> Everything goes fine, i observed one side effect regarding "sf probe" command:
> 
> STM32MP> sf probe  
> SF: Detected mx66l51235l at 0 with page size 256 Bytes, erase size 64 KiB, total 64 MiB
> STM32MP> sf probe 1    
> SF: Detected mx66l51235l at 1 with page size 256 Bytes, erase size 64 KiB, total 64 MiB
> 
> Here the flash name is mx66l51235l at 0 or mx66l51235l at 1 and no more mx66l51235l.

I too tried that change (using (char *)nor->dev->name as mtd name).

The thing is that the name "mx66l51235l" is determined from the SPI NOR
ID (not the device-tree), so if you solder a different NOR, the name
will be different. Meanwhile dts name is always the same.

I think the mtd command should at least inform the user what kind of SPI
NOR is soldered on the board.

So one solution is to use device-tree name to select the NOR, but still
print the name determined from SPI ID somewhere.

Second solution is to allow selecting the SPI by number, i.e. (the n-th
enumerated SPI).

(BTW regarding your dts node names, the node names should be spi-nor at 0
 and spi-nor at 1. Yes, I know that spi-nor is not documented in
 device-tree bindings yet, but this would be consistent with other
 device-tree bindings in Linux.)

Marek