[ARM] replace remaining __FUNCTION__ occurrences
[linux-2.6.git] / arch / arm / mach-pxa / dma.c
1 /*
2  *  linux/arch/arm/mach-pxa/dma.c
3  *
4  *  PXA DMA registration and IRQ dispatching
5  *
6  *  Author:     Nicolas Pitre
7  *  Created:    Nov 15, 2001
8  *  Copyright:  MontaVista Software Inc.
9  *
10  *  This program is free software; you can redistribute it and/or modify
11  *  it under the terms of the GNU General Public License version 2 as
12  *  published by the Free Software Foundation.
13  */
14
15 #include <linux/module.h>
16 #include <linux/init.h>
17 #include <linux/kernel.h>
18 #include <linux/interrupt.h>
19 #include <linux/errno.h>
20
21 #include <asm/system.h>
22 #include <asm/irq.h>
23 #include <asm/hardware.h>
24 #include <asm/dma.h>
25
26 #include <asm/arch/pxa-regs.h>
27
28 struct dma_channel {
29         char *name;
30         pxa_dma_prio prio;
31         void (*irq_handler)(int, void *);
32         void *data;
33 };
34
35 static struct dma_channel *dma_channels;
36 static int num_dma_channels;
37
38 int pxa_request_dma (char *name, pxa_dma_prio prio,
39                          void (*irq_handler)(int, void *),
40                          void *data)
41 {
42         unsigned long flags;
43         int i, found = 0;
44
45         /* basic sanity checks */
46         if (!name || !irq_handler)
47                 return -EINVAL;
48
49         local_irq_save(flags);
50
51         do {
52                 /* try grabbing a DMA channel with the requested priority */
53                 for (i = 0; i < num_dma_channels; i++) {
54                         if ((dma_channels[i].prio == prio) &&
55                             !dma_channels[i].name) {
56                                 found = 1;
57                                 break;
58                         }
59                 }
60                 /* if requested prio group is full, try a hier priority */
61         } while (!found && prio--);
62
63         if (found) {
64                 DCSR(i) = DCSR_STARTINTR|DCSR_ENDINTR|DCSR_BUSERR;
65                 dma_channels[i].name = name;
66                 dma_channels[i].irq_handler = irq_handler;
67                 dma_channels[i].data = data;
68         } else {
69                 printk (KERN_WARNING "No more available DMA channels for %s\n", name);
70                 i = -ENODEV;
71         }
72
73         local_irq_restore(flags);
74         return i;
75 }
76
77 void pxa_free_dma (int dma_ch)
78 {
79         unsigned long flags;
80
81         if (!dma_channels[dma_ch].name) {
82                 printk (KERN_CRIT
83                         "%s: trying to free channel %d which is already freed\n",
84                         __func__, dma_ch);
85                 return;
86         }
87
88         local_irq_save(flags);
89         DCSR(dma_ch) = DCSR_STARTINTR|DCSR_ENDINTR|DCSR_BUSERR;
90         dma_channels[dma_ch].name = NULL;
91         local_irq_restore(flags);
92 }
93
94 static irqreturn_t dma_irq_handler(int irq, void *dev_id)
95 {
96         int i, dint = DINT;
97
98         for (i = 0; i < num_dma_channels; i++) {
99                 if (dint & (1 << i)) {
100                         struct dma_channel *channel = &dma_channels[i];
101                         if (channel->name && channel->irq_handler) {
102                                 channel->irq_handler(i, channel->data);
103                         } else {
104                                 /*
105                                  * IRQ for an unregistered DMA channel:
106                                  * let's clear the interrupts and disable it.
107                                  */
108                                 printk (KERN_WARNING "spurious IRQ for DMA channel %d\n", i);
109                                 DCSR(i) = DCSR_STARTINTR|DCSR_ENDINTR|DCSR_BUSERR;
110                         }
111                 }
112         }
113         return IRQ_HANDLED;
114 }
115
116 int __init pxa_init_dma(int num_ch)
117 {
118         int i, ret;
119
120         dma_channels = kzalloc(sizeof(struct dma_channel) * num_ch, GFP_KERNEL);
121         if (dma_channels == NULL)
122                 return -ENOMEM;
123
124         ret = request_irq(IRQ_DMA, dma_irq_handler, IRQF_DISABLED, "DMA", NULL);
125         if (ret) {
126                 printk (KERN_CRIT "Wow!  Can't register IRQ for DMA\n");
127                 kfree(dma_channels);
128                 return ret;
129         }
130
131         /* dma channel priorities on pxa2xx processors:
132          * ch 0 - 3,  16 - 19  <--> (0) DMA_PRIO_HIGH
133          * ch 4 - 7,  20 - 23  <--> (1) DMA_PRIO_MEDIUM
134          * ch 8 - 15, 24 - 31  <--> (2) DMA_PRIO_LOW
135          */
136         for (i = 0; i < num_ch; i++)
137                 dma_channels[i].prio = min((i & 0xf) >> 2, DMA_PRIO_LOW);
138
139         num_dma_channels = num_ch;
140         return 0;
141 }
142
143 EXPORT_SYMBOL(pxa_request_dma);
144 EXPORT_SYMBOL(pxa_free_dma);