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/drivers/net/caif/caif_shm_u5500.c

https://bitbucket.org/slukk/jb-tsm-kernel-4.2
C | 129 lines | 81 code | 25 blank | 23 comment | 9 complexity | 4d80827c7d66d8a81ec8ef6a57fe6f6f MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
  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/version.h>
 11#include <linux/init.h>
 12#include <linux/module.h>
 13#include <linux/netdevice.h>
 14#include <mach/mbox-db5500.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);