1/*
  2 * Copyright (C) ST-Ericsson AB 2010
  3 * Contact: Sjur Brendeland / sjur.brandeland@stericsson.com
  4 * Author:  Amarnath Revanna / amarnath.bangalore.revanna@stericsson.com
  5 * License terms: GNU General Public License (GPL) version 2
  6 */
  7
  8#define pr_fmt(fmt) KBUILD_MODNAME ":" fmt
  9
 10#include <linux/init.h>
 11#include <linux/module.h>
 12#include <linux/netdevice.h>
 13#include <mach/mbox-db5500.h>
 14#include <net/caif/caif_shm.h>
 15
 16MODULE_LICENSE("GPL");
 17MODULE_DESCRIPTION("CAIF Shared Memory protocol driver");
 18
 19#define MAX_SHM_INSTANCES	1
 20
 21enum {
 22	MBX_ACC0,
 23	MBX_ACC1,
 24	MBX_DSP
 25};
 26
 27static struct shmdev_layer shmdev_lyr[MAX_SHM_INSTANCES];
 28
 29static unsigned int shm_start;
 30static unsigned int shm_size;
 31
 32module_param(shm_size, uint  , 0440);
 33MODULE_PARM_DESC(shm_total_size, "Start of SHM shared memory");
 34
 35module_param(shm_start, uint  , 0440);
 36MODULE_PARM_DESC(shm_total_start, "Total Size of SHM shared memory");
 37
 38static int shmdev_send_msg(u32 dev_id, u32 mbx_msg)
 39{
 40	/* Always block until msg is written successfully */
 41	mbox_send(shmdev_lyr[dev_id].hmbx, mbx_msg, true);
 42	return 0;
 43}
 44
 45static int shmdev_mbx_setup(void *pshmdrv_cb, struct shmdev_layer *pshm_dev,
 46							 void *pshm_drv)
 47{
 48	/*
 49	 * For UX5500, we have only 1 SHM instance which uses MBX0
 50	 * for communication with the peer modem
 51	 */
 52	pshm_dev->hmbx = mbox_setup(MBX_ACC0, pshmdrv_cb, pshm_drv);
 53
 54	if (!pshm_dev->hmbx)
 55		return -ENODEV;
 56	else
 57		return 0;
 58}
 59
 60static int __init caif_shmdev_init(void)
 61{
 62	int i, result;
 63
 64	/* Loop is currently overkill, there is only one instance */
 65	for (i = 0; i < MAX_SHM_INSTANCES; i++) {
 66
 67		shmdev_lyr[i].shm_base_addr = shm_start;
 68		shmdev_lyr[i].shm_total_sz = shm_size;
 69
 70		if (((char *)shmdev_lyr[i].shm_base_addr == NULL)
 71			       || (shmdev_lyr[i].shm_total_sz <= 0))	{
 72			pr_warn("ERROR,"
 73				"Shared memory Address and/or Size incorrect"
 74				", Bailing out ...\n");
 75			result = -EINVAL;
 76			goto clean;
 77		}
 78
 79		pr_info("SHM AREA (instance %d) STARTS"
 80			" AT %p\n", i, (char *)shmdev_lyr[i].shm_base_addr);
 81
 82		shmdev_lyr[i].shm_id = i;
 83		shmdev_lyr[i].pshmdev_mbxsend = shmdev_send_msg;
 84		shmdev_lyr[i].pshmdev_mbxsetup = shmdev_mbx_setup;
 85
 86		/*
 87		 * Finally, CAIF core module is called with details in place:
 88		 * 1. SHM base address
 89		 * 2. SHM size
 90		 * 3. MBX handle
 91		 */
 92		result = caif_shmcore_probe(&shmdev_lyr[i]);
 93		if (result) {
 94			pr_warn("ERROR[%d],"
 95				"Could not probe SHM core (instance %d)"
 96				" Bailing out ...\n", result, i);
 97			goto clean;
 98		}
 99	}
100
101	return 0;
102
103clean:
104	/*
105	 * For now, we assume that even if one instance of SHM fails, we bail
106	 * out of the driver support completely. For this, we need to release
107	 * any memory allocated and unregister any instance of SHM net device.
108	 */
109	for (i = 0; i < MAX_SHM_INSTANCES; i++) {
110		if (shmdev_lyr[i].pshm_netdev)
111			unregister_netdev(shmdev_lyr[i].pshm_netdev);
112	}
113	return result;
114}
115
116static void __exit caif_shmdev_exit(void)
117{
118	int i;
119
120	for (i = 0; i < MAX_SHM_INSTANCES; i++) {
121		caif_shmcore_remove(shmdev_lyr[i].pshm_netdev);
122		kfree((void *)shmdev_lyr[i].shm_base_addr);
123	}
124
125}
126
127module_init(caif_shmdev_init);
128module_exit(caif_shmdev_exit);