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b8a16e1f BS |
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 | ||
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 | */ | |
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 | ||
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 |