tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 ":" __func__ "():" fmt
9
10#include <linux/version.h>
11#include <linux/init.h>
12#include <linux/module.h>
13#include <linux/netdevice.h>
14#include <mach/mbox.h>
15#include <net/caif/caif_shm.h>
16
17MODULE_LICENSE("GPL");
18MODULE_DESCRIPTION("CAIF Shared Memory protocol driver");
19
20#define MAX_SHM_INSTANCES 1
21
22enum {
23 MBX_ACC0,
24 MBX_ACC1,
25 MBX_DSP
26};
27
28static struct shmdev_layer shmdev_lyr[MAX_SHM_INSTANCES];
29
30static unsigned int shm_start;
31static unsigned int shm_size;
32
33module_param(shm_size, uint , 0440);
34MODULE_PARM_DESC(shm_total_size, "Start of SHM shared memory");
35
36module_param(shm_start, uint , 0440);
37MODULE_PARM_DESC(shm_total_start, "Total Size of SHM shared memory");
38
39static int shmdev_send_msg(u32 dev_id, u32 mbx_msg)
40{
41 /* Always block until msg is written successfully */
42 mbox_send(shmdev_lyr[dev_id].hmbx, mbx_msg, true);
43 return 0;
44}
45
46static int shmdev_mbx_setup(void *pshmdrv_cb, struct shmdev_layer *pshm_dev,
47 void *pshm_drv)
48{
49 /*
50 * For UX5500, we have only 1 SHM instance which uses MBX0
51 * for communication with the peer modem
52 */
53 pshm_dev->hmbx = mbox_setup(MBX_ACC0, pshmdrv_cb, pshm_drv);
54
55 if (!pshm_dev->hmbx)
56 return -ENODEV;
57 else
58 return 0;
59}
60
61static int __init caif_shmdev_init(void)
62{
63 int i, result;
64
65 /* Loop is currently overkill, there is only one instance */
66 for (i = 0; i < MAX_SHM_INSTANCES; i++) {
67
68 shmdev_lyr[i].shm_base_addr = shm_start;
69 shmdev_lyr[i].shm_total_sz = shm_size;
70
71 if (((char *)shmdev_lyr[i].shm_base_addr == NULL)
72 || (shmdev_lyr[i].shm_total_sz <= 0)) {
73 pr_warn("ERROR,"
74 "Shared memory Address and/or Size incorrect"
75 ", Bailing out ...\n");
76 result = -EINVAL;
77 goto clean;
78 }
79
80 pr_info("SHM AREA (instance %d) STARTS"
81 " AT %p\n", i, (char *)shmdev_lyr[i].shm_base_addr);
82
83 shmdev_lyr[i].shm_id = i;
84 shmdev_lyr[i].pshmdev_mbxsend = shmdev_send_msg;
85 shmdev_lyr[i].pshmdev_mbxsetup = shmdev_mbx_setup;
86
87 /*
88 * Finally, CAIF core module is called with details in place:
89 * 1. SHM base address
90 * 2. SHM size
91 * 3. MBX handle
92 */
93 result = caif_shmcore_probe(&shmdev_lyr[i]);
94 if (result) {
95 pr_warn("ERROR[%d],"
96 "Could not probe SHM core (instance %d)"
97 " Bailing out ...\n", result, i);
98 goto clean;
99 }
100 }
101
102 return 0;
103
104clean:
105 /*
106 * For now, we assume that even if one instance of SHM fails, we bail
107 * out of the driver support completely. For this, we need to release
108 * any memory allocated and unregister any instance of SHM net device.
109 */
110 for (i = 0; i < MAX_SHM_INSTANCES; i++) {
111 if (shmdev_lyr[i].pshm_netdev)
112 unregister_netdev(shmdev_lyr[i].pshm_netdev);
113 }
114 return result;
115}
116
117static void __exit caif_shmdev_exit(void)
118{
119 int i;
120
121 for (i = 0; i < MAX_SHM_INSTANCES; i++) {
122 caif_shmcore_remove(shmdev_lyr[i].pshm_netdev);
123 kfree((void *)shmdev_lyr[i].shm_base_addr);
124 }
125
126}
127
128module_init(caif_shmdev_init);
129module_exit(caif_shmdev_exit);