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gerrit-public.fairphone.software / kernel / msm-4.9 / f6e63cfb5cfcccca510672155b90dd39bf45a35f / . / arch / sh / drivers / dma / dma-g2.c
blob: 231e3f6fb28faa0e8602cb1bfb98c4687cad5c17 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]1/*
2 * arch/sh/drivers/dma/dma-g2.c
3 *
4 * G2 bus DMA support
5 *
6 * Copyright (C) 2003, 2004 Paul Mundt
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file "COPYING" in the main directory of this archive
10 * for more details.
11 */
12#include <linux/init.h>
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/interrupt.h>
16
17#include <asm/mach/sysasic.h>
18#include <asm/mach/dma.h>
19#include <asm/dma.h>
20
21struct g2_channel {
22 unsigned long g2_addr; /* G2 bus address */
23 unsigned long root_addr; /* Root bus (SH-4) address */
24 unsigned long size; /* Size (in bytes), 32-byte aligned */
25 unsigned long direction; /* Transfer direction */
26 unsigned long ctrl; /* Transfer control */
27 unsigned long chan_enable; /* Channel enable */
28 unsigned long xfer_enable; /* Transfer enable */
29 unsigned long xfer_stat; /* Transfer status */
30} __attribute__ ((aligned(32)));
31
32struct g2_status {
33 unsigned long g2_addr;
34 unsigned long root_addr;
35 unsigned long size;
36 unsigned long status;
37} __attribute__ ((aligned(16)));
38
39struct g2_dma_info {
40 struct g2_channel channel[G2_NR_DMA_CHANNELS];
41 unsigned long pad1[G2_NR_DMA_CHANNELS];
42 unsigned long wait_state;
43 unsigned long pad2[10];
44 unsigned long magic;
45 struct g2_status status[G2_NR_DMA_CHANNELS];
46} __attribute__ ((aligned(256)));
47
48static volatile struct g2_dma_info *g2_dma = (volatile struct g2_dma_info *)0xa05f7800;
49
50static irqreturn_t g2_dma_interrupt(int irq, void *dev_id, struct pt_regs *regs)
51{
52 /* FIXME: Do some meaningful completion work here.. */
53 return IRQ_HANDLED;
54}
55
56static struct irqaction g2_dma_irq = {
57 .name = "g2 DMA handler",
58 .handler = g2_dma_interrupt,
59 .flags = SA_INTERRUPT,
60};
61
62static int g2_enable_dma(struct dma_channel *chan)
63{
64 unsigned int chan_nr = chan->chan;
65
66 g2_dma->channel[chan_nr].chan_enable = 1;
67 g2_dma->channel[chan_nr].xfer_enable = 1;
68
69 return 0;
70}
71
72static int g2_disable_dma(struct dma_channel *chan)
73{
74 unsigned int chan_nr = chan->chan;
75
76 g2_dma->channel[chan_nr].chan_enable = 0;
77 g2_dma->channel[chan_nr].xfer_enable = 0;
78
79 return 0;
80}
81
82static int g2_xfer_dma(struct dma_channel *chan)
83{
84 unsigned int chan_nr = chan->chan;
85
86 if (chan->sar & 31) {
87 printk("g2dma: unaligned source 0x%lx\n", chan->sar);
88 return -EINVAL;
89 }
90
91 if (chan->dar & 31) {
92 printk("g2dma: unaligned dest 0x%lx\n", chan->dar);
93 return -EINVAL;
94 }
95
96 /* Align the count */
97 if (chan->count & 31)
98 chan->count = (chan->count + (32 - 1)) & ~(32 - 1);
99
100 /* Fixup destination */
101 chan->dar += 0xa0800000;
102
103 /* Fixup direction */
104 chan->mode = !chan->mode;
105
106 flush_icache_range((unsigned long)chan->sar, chan->count);
107
108 g2_disable_dma(chan);
109
110 g2_dma->channel[chan_nr].g2_addr = chan->dar & 0x1fffffe0;
111 g2_dma->channel[chan_nr].root_addr = chan->sar & 0x1fffffe0;
112 g2_dma->channel[chan_nr].size = (chan->count & ~31) | 0x80000000;
113 g2_dma->channel[chan_nr].direction = chan->mode;
114
115 /*
116 * bit 0 - ???
117 * bit 1 - if set, generate a hardware event on transfer completion
118 * bit 2 - ??? something to do with suspend?
119 */
120 g2_dma->channel[chan_nr].ctrl = 5; /* ?? */
121
122 g2_enable_dma(chan);
123
124 /* debug cruft */
125 pr_debug("count, sar, dar, mode, ctrl, chan, xfer: %ld, 0x%08lx, "
126 "0x%08lx, %ld, %ld, %ld, %ld\n",
127 g2_dma->channel[chan_nr].size,
128 g2_dma->channel[chan_nr].root_addr,
129 g2_dma->channel[chan_nr].g2_addr,
130 g2_dma->channel[chan_nr].direction,
131 g2_dma->channel[chan_nr].ctrl,
132 g2_dma->channel[chan_nr].chan_enable,
133 g2_dma->channel[chan_nr].xfer_enable);
134
135 return 0;
136}
137
138static struct dma_ops g2_dma_ops = {
139 .xfer = g2_xfer_dma,
140};
141
142static struct dma_info g2_dma_info = {
143 .name = "G2 DMA",
144 .nr_channels = 4,
145 .ops = &g2_dma_ops,
146 .flags = DMAC_CHANNELS_TEI_CAPABLE,
147};
148
149static int __init g2_dma_init(void)
150{
151 setup_irq(HW_EVENT_G2_DMA, &g2_dma_irq);
152
153 /* Magic */
154 g2_dma->wait_state = 27;
155 g2_dma->magic = 0x4659404f;
156
157 return register_dmac(&g2_dma_info);
158}
159
160static void __exit g2_dma_exit(void)
161{
162 free_irq(HW_EVENT_G2_DMA, 0);
163}
164
165subsys_initcall(g2_dma_init);
166module_exit(g2_dma_exit);
167
168MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");
169MODULE_DESCRIPTION("G2 bus DMA driver");
170MODULE_LICENSE("GPL");
171