spi protocol driver's probe() not being called

spi protocol driver's probe() not being called

[Graham Gower]

Hi,
I'm having trouble getting a the rtc-m41t94.c spi protocol driver's
probe function to be called on our platform, for which I am writing a
controller driver.

We have a linux 2.6.24.3 kernel patched to support our mips SOC. I have
merged the rtc-m41t94.c protocol driver from 2.6.28. I have begun to
write an spi controller driver for our SOC, called jz_spi.c.

Now, the jz_spi init and probe functions are being called successfully
and does not report any failures. In addition, I added printk()s to the
rtc-m41t94 driver and its init gets called, but its probe does not.

I'm hoping someone can point out what I am missing, a description of my
current code follows.


I have added the relevant platform_device bits:

static struct resource jz_spi_resources[] = {
    [0] = {
        .start          = CPHYSADDR(SSI_BASE),
        .end            = CPHYSADDR(SSI_BASE) + 0xfff,
        .flags          = IORESOURCE_MEM,
    },
    [1] = {
        .start          = IRQ_SSI,
        .end            = IRQ_SSI,
        .flags          = IORESOURCE_IRQ,
    }
};

static u64 jz_spi_dmamask =  ~(u32)0;

static struct platform_device jz_spi_device = {
    .name = "jz_spi",
    .id = 0,
    .dev = {
        .dma_mask               = &jz_spi_dmamask,
        .coherent_dma_mask      = 0xffffffff,
    },
    .num_resources  = ARRAY_SIZE(jz_spi_resources),
    .resource       = jz_spi_resources,
};

static struct platform_device *jz_platform_devices[] __initdata = {

    /* trimmed for brevity
    ...
    */

    &jz_spi_device,
};

static int __init jz_platform_init(void)
{
    return platform_add_devices(jz_platform_devices, ARRAY_SIZE(jz_platform_devices));
}



------------------------------------------------------------------------

I have added the relevant spi_board_info bits:

static struct spi_board_info spi_board_info[] __initdata = {
{
    .modalias    = "rtc-m41t94",
    .max_speed_hz    = 1*1000*1000,
    .bus_num    = 0,
    .chip_select    = 1,
},
};

void __init jz_board_setup(void)
{

    /* trimmed for brevity
    ...
    */
    
    spi_register_board_info(spi_board_info, ARRAY_SIZE(spi_board_info));
}



------------------------------------------------------------------------
I have a platform_driver whose probe function calls spi_alloc_master
followed by spi_register_master. Yes, this is largely incomplete.


/*
* jz_spi.c
*/

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
#include <asm/jzsoc.h>

#define dprintk(fmt, args...) printk(KERN_INFO "%s: %d: " fmt, __FUNCTION__, __LINE__, ##args)

struct jz_spi {
    int irq;
};

static int
jz_spi_setup(struct spi_device *spi)
{
    dprintk("\n");

    if (spi->chip_select == 0)
        __ssi_select_ce();
    else if (spi->chip_select == 1)
        __ssi_select_ce2();
    else {
        printk(KERN_ERR "%s: invalid chip_select %d\n",
                __FUNCTION__, spi->chip_select);
        return -EINVAL;
    }

    if (spi->mode & SPI_LSB_FIRST)
        __ssi_set_lsb();
    else
        __ssi_set_msb();

    if (spi->mode & SPI_LOOP)
        __ssi_enable_loopback();
    else
        __ssi_disable_loopback();

    if (spi->mode & SPI_CPOL)
        __ssi_set_spi_clock_polarity(1);
    else
        __ssi_set_spi_clock_polarity(0);

    if (spi->mode & SPI_CPHA)
        __ssi_set_spi_clock_phase(1);
    else
        __ssi_set_spi_clock_phase(0);

    return 0;
}

static int
jz_spi_transfer(struct spi_device *spi, struct spi_message *msg)
{
    dprintk("\n");
    return 0;
}

static void
jz_spi_cleanup(struct spi_device *spi)
{
    dprintk("\n");
}

static irqreturn_t
jz_spi_irqhandler(int irq, void *dev_id)
{
    return IRQ_HANDLED;
}

static int
jz_spi_probe(struct platform_device *pdev)
{
    struct spi_master *master;
    struct jz_spi *js;
    int ret, irq;

    dprintk("\n");

    irq = platform_get_irq(pdev, 0);
    if (irq < 0) {
        printk(KERN_ERR "%s: Couldn't get platform irq\n",
                __FUNCTION__);
        ret = irq;
        goto err0;
    }

    master = spi_alloc_master(&pdev->dev, sizeof(struct jz_spi));
    if (master == NULL) {
        printk(KERN_ERR "%s: Couldn't allocate spi master\n",
                __FUNCTION__);
        ret = -ENOMEM;
        goto err0;
    }

    master->bus_num = 0;
    master->num_chipselect = 2;
    master->setup = jz_spi_setup;
    master->transfer = jz_spi_transfer;
    master->cleanup = jz_spi_cleanup;

    platform_set_drvdata(pdev, master);
    js = spi_master_get_devdata(master);

    js->irq = irq;

    ret = request_irq(irq, jz_spi_irqhandler, 0, pdev->dev.bus_id, master);
    if (ret) {
        printk(KERN_ERR "%s: Couldn't obtain irq %d\n",
                __FUNCTION__, irq);
        goto err1;
    }

    dprintk("Obtained irq %d\n", irq);

    __gpio_as_ssi();
    __ssi_spi_format();
    __ssi_set_rx_trigger(1);

    if ((ret = spi_register_master(master))) {
        printk(KERN_ERR "%s: Couldn't register spi master\n",
                __FUNCTION__);
        goto err2;
    }

    return 0;

err2:
    free_irq(irq, master);
err1:
    spi_master_put(master);
err0:
    return ret;
}

static int
jz_spi_remove(struct platform_device *pdev)
{
    struct spi_master *master = platform_get_drvdata(pdev);
    struct jz_spi *js = spi_master_get_devdata(master);

    dprintk("\n");

    spi_unregister_master(master);
    free_irq(js->irq, master);
    spi_master_put(master);

    return 0;
}

#ifdef CONFIG_PM
static int
jz_spi_suspend(struct platform_device *pdev, pm_message_t state)
{
    return 0;
}

static int
jz_spi_resume(struct platform_device *pdev)
{
    return 0;
}
#else
#define jz_spi_suspend NULL
#define jz_spi_resum NULL
#endif /* CONFIG_PM */

struct platform_driver jz_spi_driver =
{
    .driver = {
        .name = "jz_spi",
        .owner = THIS_MODULE,
    },
    .probe = jz_spi_probe,
    .remove = jz_spi_remove,
    .suspend = jz_spi_suspend,
    .resume = jz_spi_resume,
};

static int __init
jz_spi_init(void)
{
    dprintk("\n");
    return platform_driver_register(&jz_spi_driver);
}

static void __exit
jz_spi_exit(void)
{
    dprintk("\n");
    platform_driver_unregister(&jz_spi_driver);
}

module_init(jz_spi_init);
module_exit(jz_spi_exit);

MODULE_AUTHOR("Graham Gower");
MODULE_LICENSE("GPL");


------------------------------------------------------------------------
My kernel config contains:

$ grep CONFIG_RTC .config | grep -v ^#
CONFIG_RTC_LIB=y
CONFIG_RTC_CLASS=m
CONFIG_RTC_INTF_SYSFS=y
CONFIG_RTC_INTF_PROC=y
CONFIG_RTC_INTF_DEV=y
CONFIG_RTC_DRV_M41T94=m

$ grep CONFIG_SPI .config | grep -v ^#
CONFIG_SPI=y
CONFIG_SPI_MASTER=y
CONFIG_SPI_JZ=m

$ grep JZ drivers/spi/Kconfig config SPI_JZ
       tristate "JZSOC SPI Controller"
       depends on JZSOC && SPI_MASTER
         Driver for the SPI Controller found on JZ4730 SOC.


Assistance would be apreciated,
-Graham


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