SPI rtc-ds1305 doesn't show /dev/rtc and doesn't bind to my spi2.1

Question

I need some help to find out why my rtc-ds1306 driver doesn't bind to the spi2.1 devices

I'm working on embedded linux (3.2.0) platform that I would like to use the spi to communicated with an RTC DS1306 and other spi devices. The platform come default with spi1.0 talk to a nor flash and I'm able to add and communicated with the spidev driver to the /dev/spi1.1 and /dev/spi2.0. The rtc-ds1305 driver is available under /sys/bus/spi/drivers/ (rtc-ds1306) but it's doesn't bind to any spi (ex:spi2.1). Spi1.1 and spi2.0 bind automatically. I don't see any error message at boot...

Can you tell me what is missing?

//---board-xxxx.c files----

static const struct flash_platform_data am335x_spi_flash = {
    .type      = "w25q64",
    .name      = "spi_flash",
};


/*
 * SPI Flash works at 80Mhz however SPI Controller works at 48MHz.
 * So setup Max speed to be less than that of Controller speed
 */
static struct spi_board_info am335x_spi0_slave_info[] = {
    {
        .modalias      = "m25p80",
        .platform_data = &am335x_spi_flash,
        .irq           = -1,
        .max_speed_hz  = 24000000,
        .bus_num       = 1,
        .chip_select   = 0,
    },
//PH140107 add spidev driver for the spi0_cs1
    {
        .modalias       = "spidev",
        .max_speed_hz   = 12000000,
        .bus_num        = 1,
        .chip_select    = 1,
        .mode       = SPI_MODE_0,
    },

};

//PH140110 add this platform_data
static const struct ds1305_platform_data am335x_spi_rtc = {
    .is_ds1306 = true,
    .en_1hz    = false,
};
/* PH140109
 * SPI RTC DS1306 (use RTC-ds1305 driver) and add SPI1_CS0 incase need it for spi1_dsp
 * So setup Max speed to be less than that of Controller speed
 */
static struct spi_board_info am335x_spi1_slave_info[] = {
    {
        .modalias       = "rtc-ds1305",
        .platform_data  = &am335x_spi_rtc,
        .max_speed_hz   = 1000000,
        .bus_num        = 2,
        .chip_select    = 1,
        .mode       = SPI_CS_HIGH | SPI_CPOL | SPI_CPHA,
    },

    {
        .modalias       = "spidev",
        .max_speed_hz   = 48000000,
        .bus_num        = 2,
        .chip_select    = 0,
        .mode       = SPI_MODE_0,
    },

};

edit: I can't find the rtc in the /dev/rtcX but in the /sys/bus/spi/devices I can see spi1.0,spi1.1,spi2.0 and spi2.1. Additionnaly in the /sys/bus/spi/drivers I can find m25p80, rtc-ds1305 and spidev. If I go in /sys/bus/spi/drivers/spidev I can see spi1.1 and spi2.0 (+ bind,uevent and unbind) but if I go to /sys/bus/spi/drivers/rtc-ds1305 there just bind,uevent and unbind.

I think I should see /dev/rtc0 and in /sys/bus/spi/drivers/rtc-ds1305 I should see spi2.1

How do you know that things aren't working as they should? Please include in your question the evidence that something is wrong and also what it would look like if everything were working properly. — dg99

Phil Phil · Accepted Answer · 2014-03-05T20:15:03

I was working on a development board so the ds1306 wasn't populated so can't answering to the rtc-ds1305 driver sanity check. When connected to the real-board it appear under /dev/rtc0.

Problem solve!

SPI rtc-ds1305 doesn't show /dev/rtc and doesn't bind to my spi2.1

1 Answers