SPI Driver

SPI Driver

[Navin Boppuri]

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Hello everyone,

The SPI driver link in LinuxPPC Embedded HOWTO by Graham is broken since
I had to kill my server machine. I will put it on some other server in a
few days. Meanwhile, if someone needs a copy, I will be glad to send it
to them. I am sending a copy with this mail too. Thanks.
 <<spi.tar>> 
Navin Boppuri

[-- Attachment #2: spi.tar --]
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Re: SPI Driver

[Jeremy Rosen]

I plan to,
but right now it is too incomplete for release. ( no support for
multiple SPI device, no multithreading protection etc...)
moreover, I am working with a development board which has no SPI
device, so it has been tested only in loopback mode (the real board
we're developing should be available soon. )

just leave me a couple of weeks to work on it, and I'll send it to
everyone...

>>> sdfg sdfg <boppuri_navin@yahoo.com> 03/14/02 09:55am >>>
Hello Jeremy,

Would you be nice enough to put those drivers on some
site and send that link to everyone on the mailing
list? Thanks.

Navin.


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

SPI driver

[LEROY Christophe]

Hi, I'm looking for an SPI driver for the PPC (MPC860), but the address
given on the HOWTO (ftp://216.118.31.75/pub/) doesn't work.
Where can I find it ?

Thanks

Christophe


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Re: SPI driver

[Alex Zeffertt]

I posted one to this list a few months ago.  It's pretty minimal, but it works.  Do a search on
Re: SPI driver

Alex

LEROY Christophe wrote:

> Hi, I'm looking for an SPI driver for the PPC (MPC860), but the address
> given on the HOWTO (ftp://216.118.31.75/pub/) doesn't work.
> Where can I find it ?
>
> Thanks
>
> Christophe
>
>
>
>


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

RE: SPI driver

[Navin Boppuri]

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I've sent these files before to the list. Do a search on them for some instructions. But should compile and work as a loadable module.

Navin.

-----Original Message-----
From: LEROY Christophe [mailto:christophe.leroy@c-s.fr]
Sent: Wednesday, April 24, 2002 6:38 AM
To: liste ppc embedded
Subject: SPI driver



Hi, I'm looking for an SPI driver for the PPC (MPC860), but the address
given on the HOWTO (ftp://216.118.31.75/pub/) doesn't work.
Where can I find it ?

Thanks

Christophe


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/


[-- Attachment #2: spi.c --]
[-- Type: application/octet-stream, Size: 13313 bytes --]

/*
 * (C) Copyright 2000
 * Navin Boppuri/Prashant Patel @ Trinet Communications Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/major.h>
#include <linux/fs.h>
#include <linux/fcntl.h>
#include <linux/malloc.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <asm/uaccess.h>
#include <asm/mpc8xx.h>
#include <asm/8xx_immap.h>
#include "commproc.h"
#include "spi.h"

#define SPI_DEBUG	1	/* Debugging needs */ 


/* fops routines for the spi driver 
 */ 
static int 
cpm_spi_open(struct inode *, struct file *);
static int 
cpm_spi_close(struct inode *, struct file *);
static ssize_t 
cpm_spi_write(struct file *,const char *, size_t, loff_t *);
static ssize_t 
cpm_spi_read(struct file *,char *, size_t, loff_t *);

/* fops data structure is used to interface the driver to the Linux Kernel 
 */
static struct 
file_operations cpm_spi_fops = {
        owner:          THIS_MODULE,
        read:           cpm_spi_read,
        write:          cpm_spi_write,
        open:           cpm_spi_open,
        release:        cpm_spi_close
};

/* spi device data structure 
 */
typedef struct spi_dev_t{

	/* pointers to rx and tx buffer descriptors  
	 */
	cbd_t  *tbdf, *rbdf;

	/* Receive and trasnmit buffer descriptors
 	 * base addresses
	 */
	ushort r_tbase, r_rbase; 

        /* spi receive buffer 
	*/
        unsigned char rbuf[CPM_SPI_MRBLR];

        /* spi receive buffer length 
	*/
        unsigned int  rlen;

        /* spi transmit buffer 
	*/
        unsigned char tbuf[CPM_SPI_MRBLR];

}spi_dev_t;

/* module related stuff  
 */
	#ifdef MODULE
		/* Module entry points for insmod and rmmod, etc  
		 */
		extern int init_module(void);
		extern int cleanup_module(void);

		/* Called locally by cleanup_module().  
		 */
		static int __init cpm_spi_init(void);
	#else
		/* Called directly by kernel init code.  
		 */
		extern int __init cpm_spi_init(void);
	#endif

	/* Used by cleanup_modules 
	 */ 
	static int __exit cpm_spi_cleanup(void);

/* end of module related stuff  
 */

/* Only one user at a time  
 */
static int	cpm_spi_flags = CPM_SPI_CLOSE;

/* pointer to spi device data  
 */
static spi_dev_t *spi_dev;


/* Helper functions to peek into tx and rx buffers  
 */
#ifdef SPI_DEBUG

	char quickhex(int i)
	{
	  if(i >= 10 ) return i - 10 + 'A';
	  return i + '0';
	}

	int quickisprint(int c)
	{
	  if( c >= 'A' && c <= 'Z' ) return 1;
	  if( c >= 'a' && c <= 'z' ) return 1;
	  if( c >= '0' && c <= '9' ) return 1;
	  return 0;
	}

	void memdump(void *pv, int num)
	{
	  int i;
	  unsigned char* pc = (unsigned char*)pv;
	  for(i = 0; i < num; i++ )
	    printk("%c%c ", quickhex(pc[i] >> 4), quickhex(pc[i] & 0x0f));
	  printk("\t");
	  for(i = 0; i < num; i++ )
	    printk("%c", quickisprint(pc[i]) ? pc[i] : '.');
	  printk("\n");
	}

#endif /* SPI_DEBUG */ 

/* init routine called when the driver module is loaded  
 */
int __init
cpm_spi_init(void)
{
	uint  dp_addr;
        volatile spi_t          *spi;   
        volatile immap_t        *immap;
        volatile sysconf8xx_t   *sys;
        volatile cpm8xx_t       *cp;
        
	/* pointer to internal registers  
	 */
	immap = (immap_t *)IMAP_ADDR;   

	/* pointer to system interface unit  	
	 */
        sys = (sysconf8xx_t*)&(((immap_t*)IMAP_ADDR)->im_siu_conf); 

	/* Get pointer to Communication Processor  
	 */
        cp = (cpm8xx_t*)&(((immap_t*)IMAP_ADDR)->im_cpm);      

	/* pointer to spi parameter ram  
	 */
        spi = (spi_t *)&cp->cp_dparam[PROFF_SPI];

	/* Allocate memory for private data  
	 */
	spi_dev = (spi_dev_t*)kmalloc(sizeof(spi_dev_t),GFP_ATOMIC);

        /* Initialize the parameter ram.
	 */

        /* We need to make sure many things are initialized to zero,
         * especially in the case of a microcode patch.
	 */
          
        spi->spi_rstate	= CPM_SPI_PARAM_INIT;
        spi->spi_rdp 	= CPM_SPI_PARAM_INIT;
        spi->spi_rbptr 	= CPM_SPI_PARAM_INIT;
        spi->spi_rbc 	= CPM_SPI_PARAM_INIT;   
        spi->spi_rxtmp 	= CPM_SPI_PARAM_INIT;
        spi->spi_tstate = CPM_SPI_PARAM_INIT;
        spi->spi_tdp 	= CPM_SPI_PARAM_INIT;
        spi->spi_tbptr 	= CPM_SPI_PARAM_INIT;
        spi->spi_tbc 	= CPM_SPI_PARAM_INIT;
        spi->spi_txtmp 	= CPM_SPI_PARAM_INIT;

        /* Allocate space for one transmit and one receive buffer
         * descriptor in the DP ram. 
	 */ 
          
        dp_addr = m8xx_cpm_dpalloc(sizeof(cbd_t) * 2);

        /* Set up the IIC parameters in the parameter ram. 
	 */
         
        spi->spi_rbase = spi_dev->r_rbase = dp_addr;
        spi->spi_tbase = spi_dev->r_tbase = dp_addr + sizeof(cbd_t);
        spi->spi_rbptr = spi->spi_rbase;
        spi->spi_tbptr = spi->spi_tbase;

        /* Set to big endian. 
	 */
        spi->spi_tfcr = SMC_EB;
        spi->spi_rfcr = SMC_EB;

        /* Set maximum receive size. 
	 */
        spi->spi_mrblr = CPM_SPI_MRBLR;

	/* Initialize Tx/Rx parameters.
	 */
        cp->cp_cpcr = mk_cr_cmd(CPM_CR_CH_SPI, CPM_CR_INIT_TRX) | CPM_CR_FLG;
        while (cp->cp_cpcr & CPM_CR_FLG);

        /* Configuring Port B to enable SPIMISO, SPIMOSI and SPICLK  
	 */
        cp->cp_pbpar |= CPM_PORTB_SPICLK | CPM_PORTB_SPIMOSI | CPM_PORTB_SPIMISO;
        cp->cp_pbdir |= CPM_PORTB_SPICLK | CPM_PORTB_SPIMOSI | CPM_PORTB_SPIMISO;
        cp->cp_pbodr &= ~(CPM_PORTB_SPICLK | CPM_PORTB_SPIMOSI | CPM_PORTB_SPIMISO);

	/* tx and rx buffer descriptors  
	 */
        spi_dev->tbdf = (cbd_t *)&cp->cp_dpmem[spi_dev->r_tbase];
        spi_dev->rbdf = (cbd_t *)&cp->cp_dpmem[spi_dev->r_rbase];

	/* initialize tx and rx bd status to not ready and not empty respectively 
	 */
        spi_dev->tbdf->cbd_sc &=  ~BD_SC_READY;
        spi_dev->rbdf->cbd_sc &=  ~BD_SC_EMPTY;

	/* register spi device  
	 */
	if (register_chrdev(CPM_SPI_MAJOR,CPM_SPI_CHRDEV,&cpm_spi_fops))
	{
		printk (KERN_WARNING CPM_SPI_CHRDEV "_init: unable to get major %d\n", CPM_SPI_MAJOR);
                return -EIO;
	}


	printk(KERN_INFO SPI_VERSION "spi0: device registered successfully\n");

return 0; /* Success */
}

/*
* Open does not have to do much, just make sure only one user.
*/
static int
cpm_spi_open(struct inode *ip, struct file *fp)
{
	/* We allow only one user of the device.
	 */
	if (cpm_spi_flags & CPM_SPI_OPEN)	
		return(EBUSY);

	/* pointer to the fops data structure  
	 */
	fp->f_op = &cpm_spi_fops;


	/* lock acess to the driver  
	 */
	cpm_spi_flags |= CPM_SPI_OPEN;


#ifdef MODULE
	/* increment module use count  
	 */
        MOD_INC_USE_COUNT; 
#endif

return(0);
}

/* Close the driver
 */
static int
cpm_spi_close(struct inode *ip, struct file *fp)
{

        volatile immap_t        *immap;
        volatile cpm8xx_t       *cp;

	/* pointer to internal registers  
	 */
        immap = (immap_t *)IMAP_ADDR;   

	/* Get pointer to Communication Processor  
	 */
        cp = (cpm8xx_t*)&(((immap_t*)IMAP_ADDR)->im_cpm);      

	/* Shut down SPI.
	 */
	 
	cp->cp_spmode = SPI_SPMODE_CLEAR;
	cp->cp_spie   = SPI_CLEAR_EVENTS;	
	cp->cp_spim   = SPI_MASK_EVENTS;

	/* release the driver  
	 */
	cpm_spi_flags &= ~CPM_SPI_OPEN;


#ifdef MODULE
        MOD_DEC_USE_COUNT; /* Decrement module use count */ 
#endif

return(0);
}


/*
 * spi write function. spi data transfer is a simultaneous operation. 
 * Both write and read operations are carried out as one io operation.
 */  
static ssize_t
cpm_spi_write(struct file *file,const char *buf, size_t count, loff_t *ppos)
{

volatile immap_t	*immap;
volatile cpm8xx_t	*cp;
volatile iop8xx_t	*iop;
int tloop = 0; /* timout variable for spi transfer */

	/* pointer to internal registers 
	 */
	immap = (immap_t *)IMAP_ADDR;   

	/* pointer to io ports  
	 */
	iop = (iop8xx_t*)&(((immap_t*)IMAP_ADDR)->im_ioport); 

	/* pointer to the communications processor  
	 */
	cp = (cpm8xx_t*)&(((immap_t*)IMAP_ADDR)->im_cpm);

	/* Initialize buffer memory to empty  
	 */
	memset((void*)spi_dev->tbuf,CPM_SPI_BUFFER_INIT,CPM_SPI_MRBLR);
	memset((void*)spi_dev->rbuf,CPM_SPI_BUFFER_INIT,CPM_SPI_MRBLR);

	/* Copy the buffer data from user space to kernel space  
	 */
	copy_from_user((void*)spi_dev->tbuf,(const void*)buf,(unsigned long)count);

#ifdef SPI_DEBUG
        printk("TX DUMP: ");memdump((void*)spi_dev->tbuf,count);/* dump of txbuffer before transmit */ 
	printk("RX DUMP: ");memdump((void*)spi_dev->rbuf,count);/* dump of rxbuffer before transmit */ 
#endif

	/*Setting tx bd status and data length 
	 */
        spi_dev->tbdf->cbd_bufaddr = __pa(spi_dev->tbuf);
	spi_dev->tbdf->cbd_sc =  BD_SC_READY | BD_SC_LAST | BD_SC_WRAP;
	spi_dev->tbdf->cbd_datlen = count;
	
	/*Setting rx bd status and data length 
	 */
        spi_dev->rbdf->cbd_bufaddr = __pa(spi_dev->rbuf);
	spi_dev->rbdf->cbd_sc = BD_SC_EMPTY | BD_SC_WRAP;
	spi_dev->rbdf->cbd_datlen = 0;	/* set by the controller on receiving the data */ 

#ifdef SPI_DEBUG
	printk("spi_dev->tbdf: 0x%x spi_dev->tbdf->cbd_bufaddr: 0x%x spi_dev->tbdf->cbd_sc:		
		 0x%x spi_dev->tbdf->cbd_datlen: 0x%x \n",spi_dev->tbdf,(uint)spi_dev->tbdf->cbd_bufaddr,	
		 (ushort)spi_dev->tbdf->cbd_sc,(ushort)spi_dev->tbdf->cbd_datlen);
	printk("spi_dev->rbdf: 0x%x spi_dev->rbdf->cbd_bufaddr: 0x%x spi_dev->rbdf->cbd_sc: 		
		0x%x spi_dev->rbdf->cbd_datlen: 0x%x \n",spi_dev->rbdf,(uint)spi_dev->rbdf->cbd_bufaddr,		
		(ushort)spi_dev->rbdf->cbd_sc,(ushort)spi_dev->rbdf->cbd_datlen);
#endif

	/* flush data cache so that CPM receives valid data  
	 */
	flush_dcache_range((unsigned long)spi_dev->tbuf, (unsigned long) (spi_dev->tbuf + count));
	flush_dcache_range((unsigned long)spi_dev->rbuf, (unsigned long) (spi_dev->rbuf + count));

	/* spi mode setting   
	 */
        cp->cp_spmode = SPI_SPMODE_DIV16 | SPI_SPMODE_REV | SPI_SPMODE_MASTER | 
			SPI_SPMODE_ENABLE | SPI_SPMODE_LEN_8 | SPI_SPMODE_PM_64;	

	/* Clear all interrupts! We use polling!  
	 */
        cp->cp_spie = SPI_CLEAR_EVENTS; /*clear all spi events*/
        cp->cp_spim = SPI_MASK_EVENTS;  /*mask all SPI events*/

	/* start spi transfer  
	 */
	cp->cp_spcom  |= SPI_SPCOM_STR | SPI_SPCOM_RESERVED;

	/* Need this delay, otherwise hangs!
	 * Delay not calculated exactly.  
	 */	
	udelay(SPI_MYSTERY_DELAY);

	/* wait till transfer is done. interrupts can be used instead.
	 * set spi_dev->tbdf->cbd_sc and spi_dev->rbdf->cb_sc to include BD_SC_INTRPT for interrupts.
	 * Timeout on transfer failure.
	 */
	while( ((spi_dev->tbdf->cbd_sc & BD_SC_READY) && (spi_dev->rbdf->cbd_sc & BD_SC_EMPTY)) || tloop++ > TOUT_LOOP);

	/* update spi data pointer with the correct data length received  
	 */
	spi_dev->rlen = spi_dev->rbdf->cbd_datlen;

#ifdef SPI_DEBUG
        printk("TX DUMP : ");memdump((void*)spi_dev->tbuf,count);/* dump of txbuffer before transmit */ 
	printk("RX DUMP : ");memdump((void*)spi_dev->rbuf,count);/* dump of rxbuffer before transmit */ 
#endif
	
#ifdef SPI_DEBUG
	printk("spi_dev->tbdf: 0x%x spi_dev->tbdf->cbd_bufaddr: 0x%x spi_dev->tbdf->cbd_sc:		
		0x%x spi_dev->tbdf->cbd_datlen: 0x%x \n",spi_dev->tbdf,(uint)spi_dev->tbdf->cbd_bufaddr,		
		(ushort)spi_dev->tbdf->cbd_sc,(ushort)spi_dev->tbdf->cbd_datlen);
	printk("spi_dev->rbdf: 0x%x spi_dev->rbdf->cbd_bufaddr: 0x%x spi_dev->rbdf->cbd_sc: 		
		0x%x spi_dev->rbdf->cbd_datlen: 0x%x \n",spi_dev->rbdf,(uint)spi_dev->rbdf->cbd_bufaddr,		
		(ushort)spi_dev->rbdf->cbd_sc,(ushort)spi_dev->rbdf->cbd_datlen);
#endif

return count; /* return the number of bytes written */	
}

/* spi read only returns data received during previous data transfer  
 */
static ssize_t
cpm_spi_read(struct file *file,char *buf, size_t count, loff_t *ppos)
{

#ifdef SPI_DEBUG
	memdump((void*)spi_dev->rbuf,spi_dev->rlen);
#endif
	/* return data received during previous spi data transfer  
	 */
	copy_to_user((void*)buf,(const void*)spi_dev->rbuf,spi_dev->rlen);
	
return spi_dev->rlen; /* return the number of bytes received during spi data transfer */ 
}

/* unregister the driver and clean up  
 */
int __exit cpm_spi_cleanup(void)
{
        int res;

	/* Free private data memory  
	 */
	kfree(spi_dev);

        if ((res = unregister_chrdev (CPM_SPI_MAJOR,CPM_SPI_CHRDEV)))
        {
                printk(KERN_WARNING CPM_SPI_CHRDEV "_cleanup: unable to release major %d\n",
                       CPM_SPI_MAJOR);
                return res;
        }
        return 0;
}

#ifdef MODULE

MODULE_AUTHOR("Navin Boppuri");
MODULE_DESCRIPTION("MPC8xx SPI Driver");

/* Called when module is loaded. Initializes the spi driver stuff  
 */
int
init_module(void)
{
        return cpm_spi_init();
}

/* Called when the module is removed.  
 */
int
cleanup_module(void)
{
        return cpm_spi_cleanup();
}
#endif



[-- Attachment #3: spi.h --]
[-- Type: application/octet-stream, Size: 2226 bytes --]

/*
*testing
 * (C) Copyright 2000
 * Navin Boppuri/Prashant Patel @ Trinet Communications Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#ifndef _PPC_SPI_8XX_H
#define _PPC_SPI_8XX_H


/* SPI init defines 
*/
#define SPI_VERSION 		"spi: Service Processor SPI driver ver. 1.1"
#define CPM_SPI_CHRDEV 		"spi"

#define CPM_SPI_BUFFER_INIT	0
#define CPM_SPI_PARAM_INIT	0
#define CPM_SPI_MRBLR		128	/* Maximum receive buffer size for SPI */
#define CPM_SPI_MAJOR		81	/* SPI device major number */
#define SPI_MYSTERY_DELAY	1000

/* SPI SPMODE Register 
 */
#define SPI_SPMODE_LOOP		((ushort)0x4000)
#define SPI_SPMODE_CI		((ushort)0x2000)
#define SPI_SPMODE_CP		((ushort)0x1000)
#define SPI_SPMODE_DIV16	((ushort)0x0800)
#define SPI_SPMODE_REV		((ushort)0x0400)
#define SPI_SPMODE_MASTER	((ushort)0x0200)
#define SPI_SPMODE_SLAVE	((ushort)0x0200)
#define SPI_SPMODE_ENABLE	((ushort)0x0100)
#define SPI_SPMODE_LEN_8	((ushort)0x0070)
#define SPI_SPMODE_PM_64	((ushort)0x000f)
#define SPI_SPMODE_CLEAR	((ushort)0x0000)

/* SPI SPCOM Register
 */
#define	SPI_SPCOM_STR		((unsigned char)0x80)
#define SPI_SPCOM_RESERVED	((unsigned char)0x00)

/* SPI Interrupt values
 */
#define SPI_CLEAR_EVENTS	0xff
#define SPI_MASK_EVENTS		0x00

/* Timeout loop count for SPI transfers
 */
#define TOUT_LOOP	5000000

/* PORT B Settings for SPI 
 */
#define CPM_PORTB_SPICLK	((ulong)0x0002)
#define CPM_PORTB_SPIMOSI	((ulong)0x0004)
#define CPM_PORTB_SPIMISO	((ulong)0x0008)

/* Handle driver access 
*/
#define CPM_SPI_CLOSE   0x00
#define CPM_SPI_OPEN    0x01

#endif