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