Topic: Pogoplug Mobile: Unable to make SPI work

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Post #1

beata

11 Mar 2015, 23:18

I wish to access an SPI flash IC at reasonable speed. The pogo mobile is the one device I possess where the hardware SPI bus is accessible by pin header. But it doesn't work!

My setup is:
MX25L6405D SOIC in a socket on a breadboard. The signal pins are all brought out to a convenient tie point and have indicator LEDs weakly pulled to ground. ~CS is pulled up with a 10K resistor.

Machine 1: Pogoplug Mobile with pin headers installed at J11 (UART) and J17 (SPI).
Machine 2: Guruplug Server Plus with jump wire connected to (U-SNAP).
Software: OpenWRT r44597, Kirkwood generic/FDT, initramfs, build patches. spi-gpio-custom, spidev, flashrom. The same build and physical medium is used to boot both devices.

Known Good: Guruplug, using spi-gpio-custom, flashrom is able to successfully perform all functions.

Post #2

danitool

12 Mar 2015, 01:08

You may need to add code to the kernel to let it be aware of the existence of spidev. Snippet code:

static struct spi_board_info pogo_spi_info[] = {
    {
        .bus_num    = 0,
        .chip_select    = 1,
        .mode        = 0,
        .max_speed_hz    = 781000,
        .modalias    = "spidev",
    },
};

snippet code for registering the the spi driver

    .spis = pogo_spi_info,
    .num_spis = ARRAY_SIZE(pogo_spi_info),

No idea at wich kernel file you should introduce this code, or check if already exists. I tested this succesfully in my own router HG556a, but I prefer to define a spi flash memory instead of spidev

static struct mtd_partition epc_partitions[] = {
    [0] = {
        .name        = "external-flash",
        .offset        = 0x0,
    },
};

static struct flash_platform_data blue5g_spiflash_data = {
    .parts        = epc_partitions,
    .nr_parts    = ARRAY_SIZE(epc_partitions),
    .max_transfer_len = 44,
};


static struct spi_board_info blue5g_spi_info[] = {
    {
        .bus_num    = 0,
        .chip_select    = 0,
        .mode        = 0,
        .max_speed_hz    = 781000,
        .modalias    = "m25p80",
        .platform_data    = &blue5g_spiflash_data,
    },
};

this way I simply use mtd.

Also remember to instal spidev kernel modules, or CONFIG_MTD_M25P80 enabled in the kernel for the last driver.

And check if you are using an slave select different to 0, or if pinmux needs to be enabled.

Post #3

mazilo

12 Mar 2015, 02:13

You should provide the patch file instead of the above snippet codes that no one knows to which file(s) they should be applied.

Post #4

beata

12 Mar 2015, 23:18

Ah, it looks like I'm missing a pinctrl setting. FWIW, my current device tree file:

/dts-v1/;

#include "kirkwood.dtsi"
#include "kirkwood-6192.dtsi"
/* kirkwood 6192 */
/ {
    model = "Cloud Engines Pogoplug Mobile";
    compatible = "cloudengines,pogov4a1", "marvell,kirkwood-88f6192", "marvell,kirkwood";

    memory {
        device_type = "memory";
        reg = <0x00000000 0x10000000>;
    };

    chosen {
        bootargs = "console=ttyS0,115200n8 earlyprintk";
    };

    ocp@f1000000 {
        pinctrl: pinctrl@10000 {
            pmx_led_green: pmx-led_green {
                marvell,pins = "mpp22";
                marvell,function = "gpio";
            };
            pmx_led_red: pmx-led_red {
                marvell,pins = "mpp24";
                marvell,function = "gpio";
            };
            pmx_sdio_cd: pmx_sdio_cd {
                marvell,pins = "mpp27";
                marvell,function = "gpio";
            };
            pmx_sdio_wp: pmx_sdio_wp {
                marvell,pins = "mpp28";
                marvell,function = "gpio";
            };
                        pmx_eject_button: pmx_eject_button {
                                marvell,pins = "mpp29";
                                marvell,function = "gpio";
                        };
            pmx_nand: pmx-nand {
                marvell,pins = "";
                marvell,function = "nand";
            };
            pmx_spi: pmx-spi {
                marvell,pins = "mpp7", "mpp1", "mpp2", "mpp3";
                marvell,function = "spi";
            };
        };
        uart0: serial@12000 {
            status = "okay";
        };
        uart1: serial@12100 {
            status = "disabled";
        };
        i2c0: i2c@11000 {
            status = "okay";
        };
        spi0: spi@10600 {
            status = "okay";
            spidev@0 {
                compatible = "spidev";
                spi-max-frequency = <10000000>;
                reg = <0>;
                mode = <0>;
            };
        };
        nand0: nand@0012f {
            chip-delay = <40>;
            status = "disabled";
        };
        rtc@10300 {
            status = "disabled";
        };
        sata@80000 {
            status = "disabled";
        };
        mvsdio@90000 {
            pinctrl-0 = <&pmx_sdio &pmx_sdio_cd &pmx_sdio_wp>;
            pinctrl-names = "default";
            cd-gpios = <&gpio0 27 1>;
            wp-gpios = <&gpio0 28 0>;
            status = "okay";
        };

    };
        gpio-keys {
                compatible = "gpio-keys";
                #address-cells = <1>;
                #size-cells = <0>;
        pinctrl-0 = <&pmx_eject_button>;
                pinctrl-names = "default";

                button@1 {
                        label = "Eject button";
                        linux,code = <KEY_EJECTCD>;
                        gpios = <&gpio0 29 GPIO_ACTIVE_LOW>;
                };
        };
    gpio-leds {
        compatible = "gpio-leds";
        pinctrl-0 = < &pmx_led_red &pmx_led_green >;
        pinctrl-names = "default";

        health {
            label = "status:green:health";
            gpios = <&gpio0 22 GPIO_ACTIVE_LOW>;
            default-state = "keep";
        };
        fault {
            label = "status:red:fault";
            gpios = <&gpio0 24 GPIO_ACTIVE_LOW>;
        };
    };
};

&mdio {
    status = "okay";

    ethphy0: ethernet-phy@0 {
        reg = <0>;
    };
};

&eth0 {
    status = "okay";
    ethernet0-port@0 {
        phy-handle = <&ethphy0>;
    };
};

The discussion might have continued from here.

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