diff options
Diffstat (limited to 'arch/arm/mach-spear/pl080.c')
-rw-r--r-- | arch/arm/mach-spear/pl080.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/arch/arm/mach-spear/pl080.c b/arch/arm/mach-spear/pl080.c new file mode 100644 index 000000000000..cfa1199d0f4a --- /dev/null +++ b/arch/arm/mach-spear/pl080.c | |||
@@ -0,0 +1,78 @@ | |||
1 | /* | ||
2 | * arch/arm/plat-spear/pl080.c | ||
3 | * | ||
4 | * DMAC pl080 definitions for SPEAr platform | ||
5 | * | ||
6 | * Copyright (C) 2012 ST Microelectronics | ||
7 | * Viresh Kumar <viresh.linux@gmail.com> | ||
8 | * | ||
9 | * This file is licensed under the terms of the GNU General Public | ||
10 | * License version 2. This program is licensed "as is" without any | ||
11 | * warranty of any kind, whether express or implied. | ||
12 | */ | ||
13 | |||
14 | #include <linux/amba/pl08x.h> | ||
15 | #include <linux/amba/bus.h> | ||
16 | #include <linux/bug.h> | ||
17 | #include <linux/err.h> | ||
18 | #include <linux/io.h> | ||
19 | #include <linux/spinlock_types.h> | ||
20 | #include <mach/spear.h> | ||
21 | #include <mach/misc_regs.h> | ||
22 | |||
23 | static spinlock_t lock = __SPIN_LOCK_UNLOCKED(x); | ||
24 | |||
25 | struct { | ||
26 | unsigned char busy; | ||
27 | unsigned char val; | ||
28 | } signals[16] = {{0, 0}, }; | ||
29 | |||
30 | int pl080_get_signal(const struct pl08x_channel_data *cd) | ||
31 | { | ||
32 | unsigned int signal = cd->min_signal, val; | ||
33 | unsigned long flags; | ||
34 | |||
35 | spin_lock_irqsave(&lock, flags); | ||
36 | |||
37 | /* Return if signal is already acquired by somebody else */ | ||
38 | if (signals[signal].busy && | ||
39 | (signals[signal].val != cd->muxval)) { | ||
40 | spin_unlock_irqrestore(&lock, flags); | ||
41 | return -EBUSY; | ||
42 | } | ||
43 | |||
44 | /* If acquiring for the first time, configure it */ | ||
45 | if (!signals[signal].busy) { | ||
46 | val = readl(DMA_CHN_CFG); | ||
47 | |||
48 | /* | ||
49 | * Each request line has two bits in DMA_CHN_CFG register. To | ||
50 | * goto the bits of current request line, do left shift of | ||
51 | * value by 2 * signal number. | ||
52 | */ | ||
53 | val &= ~(0x3 << (signal * 2)); | ||
54 | val |= cd->muxval << (signal * 2); | ||
55 | writel(val, DMA_CHN_CFG); | ||
56 | } | ||
57 | |||
58 | signals[signal].busy++; | ||
59 | signals[signal].val = cd->muxval; | ||
60 | spin_unlock_irqrestore(&lock, flags); | ||
61 | |||
62 | return signal; | ||
63 | } | ||
64 | |||
65 | void pl080_put_signal(const struct pl08x_channel_data *cd, int signal) | ||
66 | { | ||
67 | unsigned long flags; | ||
68 | |||
69 | spin_lock_irqsave(&lock, flags); | ||
70 | |||
71 | /* if signal is not used */ | ||
72 | if (!signals[signal].busy) | ||
73 | BUG(); | ||
74 | |||
75 | signals[signal].busy--; | ||
76 | |||
77 | spin_unlock_irqrestore(&lock, flags); | ||
78 | } | ||