393 lines
9.0 KiB
C
393 lines
9.0 KiB
C
/*
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* spi-dev.c - spi-bus driver, char device interface
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*
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* Copyright (C) 2006 Samsung Electronics Co. Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <asm/dma.h>
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#include <asm/arch/dma.h>
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//#include <linux/config.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/fs.h>
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#include <linux/slab.h>
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#include <linux/smp_lock.h>
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//#include <linux/devfs_fs_kernel.h>
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#include <linux/init.h>
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#include <linux/dma-mapping.h>
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#include "spi-dev.h"
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#include <asm/uaccess.h>
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#undef debug
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//#define debug
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#ifdef debug
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#define CRDEBUG printk("%s :: %d\n",__FUNCTION__,__LINE__)
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#else
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#define CRDEBUG
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#endif
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//#define pr_debuf printk
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#define BUFFER_SIZE 65536 //8192 for perf measurement
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#define SPI_MINORS 2
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static struct spi_dev *spi_dev_array[SPI_MINORS];
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static spinlock_t (spi_dev_array_lock);
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static struct spi_dev *attach_to_spi_dev_array(struct spi_dev *spi_dev)
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{
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CRDEBUG;
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spin_lock(&spi_dev_array_lock);
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if (spi_dev_array[spi_dev->minor]) {
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spin_unlock(&spi_dev_array_lock);
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dev_err(&spi_dev->dev, "spi-dev already has a device assigned to this adapter\n");
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goto error;
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}
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spi_dev_array[spi_dev->minor] = spi_dev;
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spin_unlock(&spi_dev_array_lock);
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return spi_dev;
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error:
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return ERR_PTR(-ENODEV);
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}
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static void return_spi_dev(struct spi_dev *spi_dev)
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{
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CRDEBUG;
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spin_lock(&spi_dev_array_lock);
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spi_dev_array[spi_dev->minor] = NULL;
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spin_unlock(&spi_dev_array_lock);
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}
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int spi_attach_spidev(struct spi_dev *spidev)
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{
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struct spi_dev *spi_dev;
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printk(KERN_INFO "spi_attach_spidev flags:0x%x\n", spidev->flags);
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CRDEBUG;
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spi_dev = attach_to_spi_dev_array(spidev);
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if (IS_ERR(spi_dev))
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return PTR_ERR(spi_dev);
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// devfs_mk_cdev(MKDEV(SPI_MAJOR, spi_dev->minor),
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// S_IFCHR|S_IRUSR|S_IWUSR, "spi/%d", spi_dev->minor);
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dev_dbg(&spi_dev->dev, "Registered as minor %d\n", spi_dev->minor);
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return 0;
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}
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int spi_detach_spidev(struct spi_dev *spi_dev)
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{
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CRDEBUG;
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// devfs_remove("spi/%d", spi_dev->minor);
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return_spi_dev(spi_dev);
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dev_dbg(&spi_dev->dev, "Adapter unregistered\n");
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return 0;
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}
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struct spi_dev *spi_dev_get_by_minor(unsigned index)
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{
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struct spi_dev *spi_dev;
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CRDEBUG;
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spin_lock(&spi_dev_array_lock);
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spi_dev = spi_dev_array[index];
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spin_unlock(&spi_dev_array_lock);
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return spi_dev;
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}
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int spi_master_recv(struct spi_dev *spi_dev, char *rbuf ,int count)
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{
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struct spi_msg msg;
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int ret;
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CRDEBUG;
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if (spi_dev->algo->master_xfer) {
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msg.flags = spi_dev->flags;
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msg.len = count;
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msg.wbuf = NULL;
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msg.rbuf = rbuf;
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/*
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dev_dbg(&spi_dev->dev, "master_recv: reading %d bytes.\n",
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count);
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*/
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down(&spi_dev->bus_lock);
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ret = spi_dev->algo->master_xfer(spi_dev, &msg, 1);
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up(&spi_dev->bus_lock);
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/*
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dev_dbg(&spi_dev->dev, "master_recv: return:%d (count:%d)\n",
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ret, count);
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*/
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/* if everything went ok (i.e. 1 msg transmitted), return #bytes
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* transmitted, else error code.
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*/
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return (ret == 1 )? count : ret;
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} else {
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dev_err(&spi_dev->dev, "SPI level transfers not supported\n");
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return -ENOSYS;
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}
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}
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int spi_master_send(struct spi_dev *spi_dev, char *wbuf, int count)
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{
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int ret;
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struct spi_msg msg;
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CRDEBUG;
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if (spi_dev->algo->master_xfer) {
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msg.flags = spi_dev->flags;
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msg.len = count;
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msg.wbuf = wbuf;
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msg.rbuf = NULL;
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/*
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dev_dbg(&spi_dev->dev, "master_send: writing %d bytes.\n",
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count);
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*/
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down(&spi_dev->bus_lock);
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ret = spi_dev->algo->master_xfer(spi_dev, &msg, 1);
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up(&spi_dev->bus_lock);
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/* if everything went ok (i.e. 1 msg transmitted), return #bytes
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* transmitted, else error code.
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*/
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return (ret == 1 ) ? count : ret;
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} else {
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dev_err(&spi_dev->dev, "SPI level transfers not supported\n");
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return -ENOSYS;
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}
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}
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static ssize_t spidev_read (struct file *file, char __user *buf, size_t count,
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loff_t *offset)
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{
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char *tmp;
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int ret;
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struct spi_dev *spi_dev = (struct spi_dev *)file->private_data;
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#ifdef CONFIG_WORD_TRANSIZE
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count = count * 4;
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#endif
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CRDEBUG;
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if (count > BUFFER_SIZE)
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count = BUFFER_SIZE;
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if(spi_dev->flags & SPI_M_DMA_MODE){
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tmp = dma_alloc_coherent(NULL, BUFFER_SIZE,
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&spi_dev->dmabuf, GFP_KERNEL | GFP_DMA);
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}else{
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tmp = kmalloc(count,GFP_KERNEL);
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}
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if (tmp==NULL)
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return -ENOMEM;
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pr_debug("%s: tmp=0x%x dmabuf=0x%x\n",
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__FUNCTION__,*tmp,spi_dev->dmabuf);
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pr_debug("spi-dev: spi-%d reading %zd bytes.\n",
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iminor(file->f_dentry->d_inode), count);
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ret = spi_master_recv(spi_dev,tmp,count);
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if (ret >= 0)
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ret = copy_to_user(buf,tmp,count)?-EFAULT:ret;
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if(spi_dev->flags & SPI_M_DMA_MODE){
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dma_free_coherent(NULL,BUFFER_SIZE,tmp,spi_dev->dmabuf);
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}else{
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kfree(tmp);
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}
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return ret;
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}
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static ssize_t spidev_write (struct file *file, const char __user *buf, size_t count,
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loff_t *offset)
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{
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int ret;
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char *tmp;
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struct spi_dev *spi_dev = (struct spi_dev *)file->private_data;
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#ifdef CONFIG_WORD_TRANSIZE
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count = count * 4;
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#endif
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if (count > BUFFER_SIZE)
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count = BUFFER_SIZE;
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if(spi_dev->flags & SPI_M_DMA_MODE){
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printk("********USE DMA MODE*********\n");
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tmp = dma_alloc_coherent(NULL, BUFFER_SIZE,
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&spi_dev->dmabuf, GFP_KERNEL | GFP_DMA);
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}
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else{
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tmp = kmalloc(count,GFP_KERNEL);
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}
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if (tmp==NULL)
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return -ENOMEM;
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pr_debug("%s: tmp=0x%x dmabuf=0x%x\n",
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__FUNCTION__,*tmp,spi_dev->dmabuf);
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if (copy_from_user(tmp, buf, count)) {
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if(spi_dev->flags & SPI_M_DMA_MODE){
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dma_free_coherent(NULL,BUFFER_SIZE,tmp,spi_dev->dmabuf);
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}else{
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kfree(tmp);
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}
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return -EFAULT;
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}
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pr_debug("spi-dev: spi-%d writing %zd bytes.\n",
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iminor(file->f_dentry->d_inode), count);
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ret = spi_master_send(spi_dev, tmp, count);
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if(spi_dev->flags & SPI_M_DMA_MODE){
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dma_free_coherent(NULL,BUFFER_SIZE,tmp,spi_dev->dmabuf);
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}else{
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kfree(tmp);
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}
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return ret;
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}
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int spidev_ioctl (struct inode *inode, struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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struct spi_dev *spi_dev = (struct spi_dev *)file->private_data;
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CRDEBUG;
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dev_dbg(&spi_dev->dev, "spi-%d ioctl, cmd: 0x%x, arg: %lx.\n",
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iminor(inode),cmd, arg);
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switch ( cmd ) {
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case SET_SPI_FLAGS:
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spi_dev->flags = (unsigned int) arg;
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break;
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case SET_SPI_RETRIES:
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spi_dev->retries = arg;
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break;
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case SET_SPI_TIMEOUT:
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spi_dev->timeout = arg;
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break;
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default:
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printk("Invalid ioctl option\n");
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}
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return 0;
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}
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static int spidev_open(struct inode *inode, struct file *file)
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{
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unsigned int minor = iminor(inode);
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struct spi_dev *spi_dev;
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CRDEBUG;
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spi_dev = spi_dev_get_by_minor(minor);
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if (!spi_dev)
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return -ENODEV;
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/* registered with adapter, passed as client to user */
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file->private_data = spi_dev;
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return 0;
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}
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#if defined(CONFIG_CPU_S3C6400) || defined(CONFIG_CPU_S3C6410)
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int spi_master_close(struct spi_dev *spi_dev)
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{
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int ret;
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CRDEBUG;
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ret = spi_dev->algo->close(spi_dev);
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return 0;
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}
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static int spidev_release(struct inode *inode, struct file *file)
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{
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struct spi_dev *spi_dev = (struct spi_dev *)file->private_data;
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int ret;
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CRDEBUG;
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ret = spi_master_close(spi_dev);
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file->private_data = NULL;
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return 0;
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}
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#else
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static int spidev_release(struct inode *inode, struct file *file)
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{
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CRDEBUG;
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file->private_data = NULL;
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return 0;
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}
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#endif
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static struct file_operations spidev_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.read = spidev_read,
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.write = spidev_write,
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.ioctl = spidev_ioctl,
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.open = spidev_open,
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.release = spidev_release,
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};
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//static int __init spi_dev_init(void)
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static int spi_dev_init(void)
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{
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int res;
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printk(KERN_INFO "spi /dev entries driver\n");
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#if defined(CONFIG_CPU_S3C6400) || defined(CONFIG_CPU_S3C6410)
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#if(SPI_CHANNEL==0)
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res = register_chrdev(SPI_MAJOR, "spi0", &spidev_fops);
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#else
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res = register_chrdev(SPI_MAJOR, "spi1", &spidev_fops);
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#endif
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#elif defined CONFIG_HS_SPI_S3C2443
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res = register_chrdev(SPI_MAJOR, "spi0", &spidev_fops);
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#else
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res = register_chrdev(SPI_MAJOR, "spi0", &spidev_fops);
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#endif
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if (res)
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goto out;
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// devfs_mk_dir("spi");
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return 0;
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out:
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printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__);
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return res;
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}
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//static void __exit spi_dev_exit(void)
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static void spi_dev_exit(void)
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{
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CRDEBUG;
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// devfs_remove("spi");
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unregister_chrdev(SPI_MAJOR,"spi");
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}
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MODULE_AUTHOR("Samsung Electronics");
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MODULE_DESCRIPTION("spi /dev entries driver");
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MODULE_LICENSE("GPL");
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module_init(spi_dev_init);
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module_exit(spi_dev_exit);
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EXPORT_SYMBOL(spi_attach_spidev);
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EXPORT_SYMBOL(spi_detach_spidev);
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//written by vivek
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EXPORT_SYMBOL(spi_master_send);
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EXPORT_SYMBOL(spi_master_recv);
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EXPORT_SYMBOL(spi_dev_get_by_minor);
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