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);
129