Hi,
I have a SPI device problem on MRST CDK.
I use a GPIO as SS because my slave device expects the SS to be low
between byte transfers.
My probe function does a read as:
int read_val;
-------
---
read_val = spi_w8r8(&spi_dev,0x20);
if ( read_val < 0 )
printk ( "spi_read err\n");
else
printk ( "spi_read %d\n",read_val );
----
--
The MRST SFI interface passes the device board info. Because, my device
is not listed in the IA32 f/w I modified the MRST.c code sfi_handle_spi_dev
function as:
while(dev->name[0])
{
if (dev->type == SFI_DEV_TYPE_SPI &&
!strncmp(dev->name, spi_info->modalias,
16)) {
if (!strncmp("spi_old_device",
spi_info->modalias, 16)){
strncpy (spi_info->modalias,
"spi_my_dev",16);
pdata =
dev->get_platform_data(spi_info);
pr_info ( "spi_old_device modalias to
spi_my_dev ");
}
else
{
pdata = dev->get_platform_data(spi_info);
}
break;
}
dev++;
}
i also modified the devs_id array to change the platform_data
{"spi_old_dev", SFI_DEV_TYPE_SPI, 0, &no_platform_data}
The issue is that for the spi_w8r8 call, i get multiple read (multiple
* (8 clock cycles/SS toggle))on the SPI bus.
Also regarding the spi->irq, is it the responsibility of the protocol
driver to register for this irq and handle it or does the spi framework or
master driver take care of this ?
Any pointers would be really helpful. ( attached is the test code )
Following is the debug log from messages after enabling spi debug (starts at
point when i call spi_w8r8()) :
Jan 10 01:54:35 localhost klogd: [ 100.202663] [<c012484f>]
__might_sleep+0xd9/0xe0
Jan 10 01:54:35 localhost klogd: [ 100.202699] [<c059da0b>]
wait_for_common+0x21/0xfd
Jan 10 01:54:35 localhost klogd: [ 100.202733] [<c034b585>] ?
dw_spi_transfer+0x97/0xaa
Jan 10 01:54:35 localhost klogd: [ 100.202764] [<c0349417>] ?
spi_async+0x7f/0x8d
Jan 10 01:54:35 localhost klogd: [ 100.202794] [<c059db68>]
wait_for_completion+0x12/0x14
Jan 10 01:54:35 localhost klogd: [ 100.202825] [<c03496d0>]
spi_sync+0x41/0x53
Jan 10 01:54:35 localhost klogd: [ 100.202859] [<c0349835>]
spi_write_then_read+0x153/0x193
Jan 10 01:54:35 localhost klogd: [ 100.202900] [<c0349875>] ?
spi_complete+0x0/0xa
Jan 10 01:54:35 localhost klogd: [ 100.202941] [<dfbed212>]
spi_trx_probe+0x1cd/0x220 [spitest]
Jan 10 01:54:35 localhost klogd: [ 100.202975] [<c0349350>]
spi_drv_probe+0x14/0x17
Jan 10 01:54:35 localhost klogd: [ 100.203009] [<c031510f>]
driver_probe_device+0x8f/0x117
Jan 10 01:54:35 localhost klogd: [ 100.203041] [<c03151da>]
__driver_attach+0x43/0x5f
Jan 10 01:54:35 localhost klogd: [ 100.203041] [<c0314a8d>]
bus_for_each_dev+0x3d/0x67
Jan 10 01:54:35 localhost klogd: [ 100.203041] [<c0314fd2>]
driver_attach+0x14/0x16
Jan 10 01:54:35 localhost klogd: [ 100.203041] [<c0315197>] ?
__driver_attach+0x0/0x5f
Jan 10 01:54:35 localhost klogd: [ 100.203041] [<c0314520>]
bus_add_driver+0x10b/0x23b
Jan 10 01:54:35 localhost klogd: [ 100.203041] [<c0287e8f>] ?
kset_find_obj+0x56/0x5e
Jan 10 01:54:35 localhost klogd: [ 100.203041] [<dfbf0000>] ?
spi_trx_init+0x0/0x4c [spitest]
Jan 10 01:54:35 localhost klogd: [ 100.203041] [<c0315417>]
driver_register+0x79/0xe0
Jan 10 01:54:35 localhost klogd: [ 100.203041] [<dfbf0000>] ?
spi_trx_init+0x0/0x4c [spitest]
Jan 10 01:54:35 localhost klogd: [ 100.203041] [<c0349e37>]
spi_register_driver+0x39/0x3e
Jan 10 01:54:35 localhost klogd: [ 100.203041] [<dfbf0018>]
spi_trx_init+0x18/0x4c [spitest]
Jan 10 01:54:35 localhost klogd: [ 100.203041] [<c0101051>]
do_one_initcall+0x4c/0x131
Jan 10 01:54:35 localhost klogd: [ 100.203041] [<c015a25e>]
sys_init_module+0x77/0x199
Jan 10 01:54:35 localhost klogd: [ 100.203041] [<c01027d7>]
sysenter_do_call+0x12/0x26
**************** my printk messages *******************************
Regards,
Tom
#include <linux/module.h>
#include <linux/init.h>
#include <linux/spi/spi.h>
#include <linux/interrupt.h>
#include "gpio.h"
#define DRVNAME "spi test driver"
static struct spi_device spi_dev;
/*---------------------------------------------------------------------------*/
static int __devinit spi_trx_probe(struct spi_device *spi)
{
int read_val;
int result;
printk(" in spi trx probe function\n" );
printk ( "Mode %d , Chip Select %d, Bits per Word %d, Speed %d Modalias %s\n",
spi->mode,spi->chip_select,spi->bits_per_word,spi->max_speed_hz,spi->modalias );
spi->mode = SPI_MODE_0;
spi->chip_select = 3;
spi->bits_per_word = 8;
spi->max_speed_hz = 1000000;
memcpy((unsigned char *)&spi_dev,(unsigned char *)spi,sizeof(struct spi_device));
result = spi_setup(spi);
if (result )
{
printk("SPI setup wasn't successful %d \n",result );
}
GPIO_Set_Value(Slave,0);
read_val = spi_w8r8(&spi_dev,0x20);
if ( read_val < 0 )
printk ( "spi_read err\n");
else
printk ( "spi_read %d\n",read_val);
GPIO_Set_Value(Slave,1);
return 0;
}
/*---------------------------------------------------------------------------*/
static void spi_trx_shutdown ( struct spi_device *spi )
{
printk(" in spi trx shut down function\n" );
}
/*---------------------------------------------------------------------------*/
static int __devexit spi_trx_remove ( struct spi_device *dev )
{
printk(" in spi trx remove function\n" );
return 0;
}
/*---------------------------------------------------------------------------*/
static int spi_trx_suspend(struct spi_device *spi, pm_message_t state)
{
printk(" in spi trx suspend function\n" );
return 0;
}
/*---------------------------------------------------------------------------*/
static int spi_trx_resume(struct spi_device *spi)
{
printk(" in spi trx resume function\n" );
return 0;
}
/*---------------------------------------------------------------------------*/
static struct spi_driver spi_trx_driver = {
.driver = {
.name = "spi_trx",
.bus = &spi_bus_type,
.owner = THIS_MODULE,
},
.probe = spi_trx_probe,
.shutdown = spi_trx_shutdown,
.remove = __devexit_p(spi_trx_remove),
.suspend = spi_trx_suspend,
.resume = spi_trx_resume
};
/*---------------------------------------------------------------------------*/
static int __init spi_trx_init(void)
{
int result = 0;
printk(" in spi trx init function\n" );
result = spi_register_driver(&spi_trx_driver);
if ( result )
{
printk("%s: driver init failed(%d)\n",
DRVNAME, result);
return result;
}
printk("%s: driver initialized successfully\n",DRVNAME);
return result;
}
/*---------------------------------------------------------------------------*/
static void __exit spi_trx_exit(void)
{
spi_unregister_driver(&spi_trx_driver);
printk("%s: driver unregistered\n", DRVNAME);
}
/*---------------------------------------------------------------------------*/
module_init(spi_trx_init);
module_exit(spi_trx_exit);
MODULE_ALIAS("SPI test Driver");
MODULE_AUTHOR("Tom");
MODULE_LICENSE("GPL");
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