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
16 MODULE_LICENSE("GPL");
17 MODULE_DESCRIPTION("CAIF Shared Memory protocol driver");
18
19 #define MAX_SHM_INSTANCES 1
20
21 enum {
22 MBX_ACC0,
23 MBX_ACC1,
24 MBX_DSP
25 };
26
27 static struct shmdev_layer shmdev_lyr[MAX_SHM_INSTANCES];
28
29 static unsigned int shm_start;
30 static unsigned int shm_size;
31
32 module_param(shm_size, uint , 0440);
33 MODULE_PARM_DESC(shm_total_size, "Start of SHM shared memory");
34
35 module_param(shm_start, uint , 0440);
36 MODULE_PARM_DESC(shm_total_start, "Total Size of SHM shared memory");
37
shmdev_send_msg(u32 dev_id,u32 mbx_msg)38 static 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
shmdev_mbx_setup(void * pshmdrv_cb,struct shmdev_layer * pshm_dev,void * pshm_drv)45 static 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
caif_shmdev_init(void)60 static 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
103 clean:
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
caif_shmdev_exit(void)116 static 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
127 module_init(caif_shmdev_init);
128 module_exit(caif_shmdev_exit);
129