caif-u5500: CAIF shared memory mailbox interface
Amarnath Revanna [Wed, 27 Oct 2010 08:34:41 +0000 (08:34 +0000)]
Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/caif/caif_shm_u5500.c [new file with mode: 0644]

diff --git a/drivers/net/caif/caif_shm_u5500.c b/drivers/net/caif/caif_shm_u5500.c
new file mode 100644 (file)
index 0000000..1cd90da
--- /dev/null
@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Contact: Sjur Brendeland / sjur.brandeland@stericsson.com
+ * Author:  Amarnath Revanna / amarnath.bangalore.revanna@stericsson.com
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":" __func__ "():" fmt
+
+#include <linux/version.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <mach/mbox.h>
+#include <net/caif/caif_shm.h>
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("CAIF Shared Memory protocol driver");
+
+#define MAX_SHM_INSTANCES      1
+
+enum {
+       MBX_ACC0,
+       MBX_ACC1,
+       MBX_DSP
+};
+
+static struct shmdev_layer shmdev_lyr[MAX_SHM_INSTANCES];
+
+static unsigned int shm_start;
+static unsigned int shm_size;
+
+module_param(shm_size, uint  , 0440);
+MODULE_PARM_DESC(shm_total_size, "Start of SHM shared memory");
+
+module_param(shm_start, uint  , 0440);
+MODULE_PARM_DESC(shm_total_start, "Total Size of SHM shared memory");
+
+static int shmdev_send_msg(u32 dev_id, u32 mbx_msg)
+{
+       /* Always block until msg is written successfully */
+       mbox_send(shmdev_lyr[dev_id].hmbx, mbx_msg, true);
+       return 0;
+}
+
+static int shmdev_mbx_setup(void *pshmdrv_cb, struct shmdev_layer *pshm_dev,
+                                                        void *pshm_drv)
+{
+       /*
+        * For UX5500, we have only 1 SHM instance which uses MBX0
+        * for communication with the peer modem
+        */
+       pshm_dev->hmbx = mbox_setup(MBX_ACC0, pshmdrv_cb, pshm_drv);
+
+       if (!pshm_dev->hmbx)
+               return -ENODEV;
+       else
+               return 0;
+}
+
+static int __init caif_shmdev_init(void)
+{
+       int i, result;
+
+       /* Loop is currently overkill, there is only one instance */
+       for (i = 0; i < MAX_SHM_INSTANCES; i++) {
+
+               shmdev_lyr[i].shm_base_addr = shm_start;
+               shmdev_lyr[i].shm_total_sz = shm_size;
+
+               if (((char *)shmdev_lyr[i].shm_base_addr == NULL)
+                              || (shmdev_lyr[i].shm_total_sz <= 0))    {
+                       pr_warn("ERROR,"
+                               "Shared memory Address and/or Size incorrect"
+                               ", Bailing out ...\n");
+                       result = -EINVAL;
+                       goto clean;
+               }
+
+               pr_info("SHM AREA (instance %d) STARTS"
+                       " AT %p\n", i, (char *)shmdev_lyr[i].shm_base_addr);
+
+               shmdev_lyr[i].shm_id = i;
+               shmdev_lyr[i].pshmdev_mbxsend = shmdev_send_msg;
+               shmdev_lyr[i].pshmdev_mbxsetup = shmdev_mbx_setup;
+
+               /*
+                * Finally, CAIF core module is called with details in place:
+                * 1. SHM base address
+                * 2. SHM size
+                * 3. MBX handle
+                */
+               result = caif_shmcore_probe(&shmdev_lyr[i]);
+               if (result) {
+                       pr_warn("ERROR[%d],"
+                               "Could not probe SHM core (instance %d)"
+                               " Bailing out ...\n", result, i);
+                       goto clean;
+               }
+       }
+
+       return 0;
+
+clean:
+       /*
+        * For now, we assume that even if one instance of SHM fails, we bail
+        * out of the driver support completely. For this, we need to release
+        * any memory allocated and unregister any instance of SHM net device.
+        */
+       for (i = 0; i < MAX_SHM_INSTANCES; i++) {
+               if (shmdev_lyr[i].pshm_netdev)
+                       unregister_netdev(shmdev_lyr[i].pshm_netdev);
+       }
+       return result;
+}
+
+static void __exit caif_shmdev_exit(void)
+{
+       int i;
+
+       for (i = 0; i < MAX_SHM_INSTANCES; i++) {
+               caif_shmcore_remove(shmdev_lyr[i].pshm_netdev);
+               kfree((void *)shmdev_lyr[i].shm_base_addr);
+       }
+
+}
+
+module_init(caif_shmdev_init);
+module_exit(caif_shmdev_exit);