linux/drivers/net/caif/caif_shm_u5500.c

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/*
* Copyright (C) ST-Ericsson AB 2010
* Contact: Sjur Brendeland / sjur.brandeland@stericsson.com
* Author: Amarnath Revanna / amarnath.bangalore.revanna@stericsson.com
* License terms: GNU General Public License (GPL) version 2
*/
#define pr_fmt(fmt) KBUILD_MODNAME ":" __func__ "():" fmt
#include <linux/version.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <mach/mbox.h>
#include <net/caif/caif_shm.h>
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("CAIF Shared Memory protocol driver");
#define MAX_SHM_INSTANCES 1
enum {
MBX_ACC0,
MBX_ACC1,
MBX_DSP
};
static struct shmdev_layer shmdev_lyr[MAX_SHM_INSTANCES];
static unsigned int shm_start;
static unsigned int shm_size;
module_param(shm_size, uint , 0440);
MODULE_PARM_DESC(shm_total_size, "Start of SHM shared memory");
module_param(shm_start, uint , 0440);
MODULE_PARM_DESC(shm_total_start, "Total Size of SHM shared memory");
static int shmdev_send_msg(u32 dev_id, u32 mbx_msg)
{
/* Always block until msg is written successfully */
mbox_send(shmdev_lyr[dev_id].hmbx, mbx_msg, true);
return 0;
}
static int shmdev_mbx_setup(void *pshmdrv_cb, struct shmdev_layer *pshm_dev,
void *pshm_drv)
{
/*
* For UX5500, we have only 1 SHM instance which uses MBX0
* for communication with the peer modem
*/
pshm_dev->hmbx = mbox_setup(MBX_ACC0, pshmdrv_cb, pshm_drv);
if (!pshm_dev->hmbx)
return -ENODEV;
else
return 0;
}
static int __init caif_shmdev_init(void)
{
int i, result;
/* Loop is currently overkill, there is only one instance */
for (i = 0; i < MAX_SHM_INSTANCES; i++) {
shmdev_lyr[i].shm_base_addr = shm_start;
shmdev_lyr[i].shm_total_sz = shm_size;
if (((char *)shmdev_lyr[i].shm_base_addr == NULL)
|| (shmdev_lyr[i].shm_total_sz <= 0)) {
pr_warn("ERROR,"
"Shared memory Address and/or Size incorrect"
", Bailing out ...\n");
result = -EINVAL;
goto clean;
}
pr_info("SHM AREA (instance %d) STARTS"
" AT %p\n", i, (char *)shmdev_lyr[i].shm_base_addr);
shmdev_lyr[i].shm_id = i;
shmdev_lyr[i].pshmdev_mbxsend = shmdev_send_msg;
shmdev_lyr[i].pshmdev_mbxsetup = shmdev_mbx_setup;
/*
* Finally, CAIF core module is called with details in place:
* 1. SHM base address
* 2. SHM size
* 3. MBX handle
*/
result = caif_shmcore_probe(&shmdev_lyr[i]);
if (result) {
pr_warn("ERROR[%d],"
"Could not probe SHM core (instance %d)"
" Bailing out ...\n", result, i);
goto clean;
}
}
return 0;
clean:
/*
* For now, we assume that even if one instance of SHM fails, we bail
* out of the driver support completely. For this, we need to release
* any memory allocated and unregister any instance of SHM net device.
*/
for (i = 0; i < MAX_SHM_INSTANCES; i++) {
if (shmdev_lyr[i].pshm_netdev)
unregister_netdev(shmdev_lyr[i].pshm_netdev);
}
return result;
}
static void __exit caif_shmdev_exit(void)
{
int i;
for (i = 0; i < MAX_SHM_INSTANCES; i++) {
caif_shmcore_remove(shmdev_lyr[i].pshm_netdev);
kfree((void *)shmdev_lyr[i].shm_base_addr);
}
}
module_init(caif_shmdev_init);
module_exit(caif_shmdev_exit);