1 /* arch/arm/mach-msm/proc_comm.c
2 *
3 * Copyright (C) 2007-2008 Google, Inc.
4 * Author: Brian Swetland <swetland@google.com>
5 *
6 * This software is licensed under the terms of the GNU General Public
7 * License version 2, as published by the Free Software Foundation, and
8 * may be copied, distributed, and modified under those terms.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 */
16
17 #include <linux/delay.h>
18 #include <linux/errno.h>
19 #include <linux/io.h>
20 #include <linux/spinlock.h>
21 #include <mach/msm_iomap.h>
22 #include <mach/system.h>
23
24 #include "proc_comm.h"
25
26 #define MSM_A2M_INT(n) (MSM_CSR_BASE + 0x400 + (n) * 4)
27
notify_other_proc_comm(void)28 static inline void notify_other_proc_comm(void)
29 {
30 writel(1, MSM_A2M_INT(6));
31 }
32
33 #define APP_COMMAND 0x00
34 #define APP_STATUS 0x04
35 #define APP_DATA1 0x08
36 #define APP_DATA2 0x0C
37
38 #define MDM_COMMAND 0x10
39 #define MDM_STATUS 0x14
40 #define MDM_DATA1 0x18
41 #define MDM_DATA2 0x1C
42
43 static DEFINE_SPINLOCK(proc_comm_lock);
44
45 /* The higher level SMD support will install this to
46 * provide a way to check for and handle modem restart.
47 */
48 int (*msm_check_for_modem_crash)(void);
49
50 /* Poll for a state change, checking for possible
51 * modem crashes along the way (so we don't wait
52 * forever while the ARM9 is blowing up).
53 *
54 * Return an error in the event of a modem crash and
55 * restart so the msm_proc_comm() routine can restart
56 * the operation from the beginning.
57 */
proc_comm_wait_for(void __iomem * addr,unsigned value)58 static int proc_comm_wait_for(void __iomem *addr, unsigned value)
59 {
60 for (;;) {
61 if (readl(addr) == value)
62 return 0;
63
64 if (msm_check_for_modem_crash)
65 if (msm_check_for_modem_crash())
66 return -EAGAIN;
67 }
68 }
69
msm_proc_comm(unsigned cmd,unsigned * data1,unsigned * data2)70 int msm_proc_comm(unsigned cmd, unsigned *data1, unsigned *data2)
71 {
72 void __iomem *base = MSM_SHARED_RAM_BASE;
73 unsigned long flags;
74 int ret;
75
76 spin_lock_irqsave(&proc_comm_lock, flags);
77
78 for (;;) {
79 if (proc_comm_wait_for(base + MDM_STATUS, PCOM_READY))
80 continue;
81
82 writel(cmd, base + APP_COMMAND);
83 writel(data1 ? *data1 : 0, base + APP_DATA1);
84 writel(data2 ? *data2 : 0, base + APP_DATA2);
85
86 notify_other_proc_comm();
87
88 if (proc_comm_wait_for(base + APP_COMMAND, PCOM_CMD_DONE))
89 continue;
90
91 if (readl(base + APP_STATUS) != PCOM_CMD_FAIL) {
92 if (data1)
93 *data1 = readl(base + APP_DATA1);
94 if (data2)
95 *data2 = readl(base + APP_DATA2);
96 ret = 0;
97 } else {
98 ret = -EIO;
99 }
100 break;
101 }
102
103 writel(PCOM_CMD_IDLE, base + APP_COMMAND);
104
105 spin_unlock_irqrestore(&proc_comm_lock, flags);
106
107 return ret;
108 }
109
110
111