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 
msm_a2m_int(uint32_t irq)26 static inline void msm_a2m_int(uint32_t irq)
27 {
28 #if defined(CONFIG_ARCH_MSM7X30)
29 	writel(1 << irq, MSM_GCC_BASE + 0x8);
30 #else
31 	writel(1, MSM_CSR_BASE + 0x400 + (irq * 4));
32 #endif
33 }
34 
notify_other_proc_comm(void)35 static inline void notify_other_proc_comm(void)
36 {
37 	msm_a2m_int(6);
38 }
39 
40 #define APP_COMMAND 0x00
41 #define APP_STATUS  0x04
42 #define APP_DATA1   0x08
43 #define APP_DATA2   0x0C
44 
45 #define MDM_COMMAND 0x10
46 #define MDM_STATUS  0x14
47 #define MDM_DATA1   0x18
48 #define MDM_DATA2   0x1C
49 
50 static DEFINE_SPINLOCK(proc_comm_lock);
51 
52 /* The higher level SMD support will install this to
53  * provide a way to check for and handle modem restart.
54  */
55 int (*msm_check_for_modem_crash)(void);
56 
57 /* Poll for a state change, checking for possible
58  * modem crashes along the way (so we don't wait
59  * forever while the ARM9 is blowing up).
60  *
61  * Return an error in the event of a modem crash and
62  * restart so the msm_proc_comm() routine can restart
63  * the operation from the beginning.
64  */
proc_comm_wait_for(void __iomem * addr,unsigned value)65 static int proc_comm_wait_for(void __iomem *addr, unsigned value)
66 {
67 	for (;;) {
68 		if (readl(addr) == value)
69 			return 0;
70 
71 		if (msm_check_for_modem_crash)
72 			if (msm_check_for_modem_crash())
73 				return -EAGAIN;
74 	}
75 }
76 
msm_proc_comm(unsigned cmd,unsigned * data1,unsigned * data2)77 int msm_proc_comm(unsigned cmd, unsigned *data1, unsigned *data2)
78 {
79 	void __iomem *base = MSM_SHARED_RAM_BASE;
80 	unsigned long flags;
81 	int ret;
82 
83 	spin_lock_irqsave(&proc_comm_lock, flags);
84 
85 	for (;;) {
86 		if (proc_comm_wait_for(base + MDM_STATUS, PCOM_READY))
87 			continue;
88 
89 		writel(cmd, base + APP_COMMAND);
90 		writel(data1 ? *data1 : 0, base + APP_DATA1);
91 		writel(data2 ? *data2 : 0, base + APP_DATA2);
92 
93 		notify_other_proc_comm();
94 
95 		if (proc_comm_wait_for(base + APP_COMMAND, PCOM_CMD_DONE))
96 			continue;
97 
98 		if (readl(base + APP_STATUS) != PCOM_CMD_FAIL) {
99 			if (data1)
100 				*data1 = readl(base + APP_DATA1);
101 			if (data2)
102 				*data2 = readl(base + APP_DATA2);
103 			ret = 0;
104 		} else {
105 			ret = -EIO;
106 		}
107 		break;
108 	}
109 
110 	writel(PCOM_CMD_IDLE, base + APP_COMMAND);
111 
112 	spin_unlock_irqrestore(&proc_comm_lock, flags);
113 
114 	return ret;
115 }
116 
117 /*
118  * We need to wait for the ARM9 to at least partially boot
119  * up before we can continue. Since the ARM9 does resource
120  * allocation, if we dont' wait we could end up crashing or in
121  * and unknown state. This function should be called early to
122  * wait on the ARM9.
123  */
proc_comm_boot_wait(void)124 void __devinit proc_comm_boot_wait(void)
125 {
126 	void __iomem *base = MSM_SHARED_RAM_BASE;
127 
128 	proc_comm_wait_for(base + MDM_STATUS, PCOM_READY);
129 
130 }
131