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12#include <linux/init.h>
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/interrupt.h>
16#include <asm/cacheflush.h>
17#include <mach/sysasic.h>
18#include <mach/dma.h>
19#include <asm/dma.h>
20
21struct g2_channel {
22 unsigned long g2_addr;
23 unsigned long root_addr;
24 unsigned long size;
25 unsigned long direction;
26 unsigned long ctrl;
27 unsigned long chan_enable;
28 unsigned long xfer_enable;
29 unsigned long xfer_stat;
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
50#define g2_bytes_remaining(i) \
51 ((g2_dma->channel[i].size - \
52 g2_dma->status[i].size) & 0x0fffffff)
53
54static irqreturn_t g2_dma_interrupt(int irq, void *dev_id)
55{
56 int i;
57
58 for (i = 0; i < G2_NR_DMA_CHANNELS; i++) {
59 if (g2_dma->status[i].status & 0x20000000) {
60 unsigned int bytes = g2_bytes_remaining(i);
61
62 if (likely(bytes == 0)) {
63 struct dma_info *info = dev_id;
64 struct dma_channel *chan = info->channels + i;
65
66 wake_up(&chan->wait_queue);
67
68 return IRQ_HANDLED;
69 }
70 }
71 }
72
73 return IRQ_NONE;
74}
75
76static int g2_enable_dma(struct dma_channel *chan)
77{
78 unsigned int chan_nr = chan->chan;
79
80 g2_dma->channel[chan_nr].chan_enable = 1;
81 g2_dma->channel[chan_nr].xfer_enable = 1;
82
83 return 0;
84}
85
86static int g2_disable_dma(struct dma_channel *chan)
87{
88 unsigned int chan_nr = chan->chan;
89
90 g2_dma->channel[chan_nr].chan_enable = 0;
91 g2_dma->channel[chan_nr].xfer_enable = 0;
92
93 return 0;
94}
95
96static int g2_xfer_dma(struct dma_channel *chan)
97{
98 unsigned int chan_nr = chan->chan;
99
100 if (chan->sar & 31) {
101 printk("g2dma: unaligned source 0x%lx\n", chan->sar);
102 return -EINVAL;
103 }
104
105 if (chan->dar & 31) {
106 printk("g2dma: unaligned dest 0x%lx\n", chan->dar);
107 return -EINVAL;
108 }
109
110
111 if (chan->count & 31)
112 chan->count = (chan->count + (32 - 1)) & ~(32 - 1);
113
114
115 chan->dar += 0xa0800000;
116
117
118 chan->mode = !chan->mode;
119
120 flush_icache_range((unsigned long)chan->sar, chan->count);
121
122 g2_disable_dma(chan);
123
124 g2_dma->channel[chan_nr].g2_addr = chan->dar & 0x1fffffe0;
125 g2_dma->channel[chan_nr].root_addr = chan->sar & 0x1fffffe0;
126 g2_dma->channel[chan_nr].size = (chan->count & ~31) | 0x80000000;
127 g2_dma->channel[chan_nr].direction = chan->mode;
128
129
130
131
132
133
134 g2_dma->channel[chan_nr].ctrl = 5;
135
136 g2_enable_dma(chan);
137
138
139 pr_debug("count, sar, dar, mode, ctrl, chan, xfer: %ld, 0x%08lx, "
140 "0x%08lx, %ld, %ld, %ld, %ld\n",
141 g2_dma->channel[chan_nr].size,
142 g2_dma->channel[chan_nr].root_addr,
143 g2_dma->channel[chan_nr].g2_addr,
144 g2_dma->channel[chan_nr].direction,
145 g2_dma->channel[chan_nr].ctrl,
146 g2_dma->channel[chan_nr].chan_enable,
147 g2_dma->channel[chan_nr].xfer_enable);
148
149 return 0;
150}
151
152static int g2_get_residue(struct dma_channel *chan)
153{
154 return g2_bytes_remaining(chan->chan);
155}
156
157static struct dma_ops g2_dma_ops = {
158 .xfer = g2_xfer_dma,
159 .get_residue = g2_get_residue,
160};
161
162static struct dma_info g2_dma_info = {
163 .name = "g2_dmac",
164 .nr_channels = 4,
165 .ops = &g2_dma_ops,
166 .flags = DMAC_CHANNELS_TEI_CAPABLE,
167};
168
169static int __init g2_dma_init(void)
170{
171 int ret;
172
173 ret = request_irq(HW_EVENT_G2_DMA, g2_dma_interrupt, IRQF_DISABLED,
174 "g2 DMA handler", &g2_dma_info);
175 if (unlikely(ret))
176 return -EINVAL;
177
178
179 g2_dma->wait_state = 27;
180 g2_dma->magic = 0x4659404f;
181
182 ret = register_dmac(&g2_dma_info);
183 if (unlikely(ret != 0))
184 free_irq(HW_EVENT_G2_DMA, 0);
185
186 return ret;
187}
188
189static void __exit g2_dma_exit(void)
190{
191 free_irq(HW_EVENT_G2_DMA, 0);
192 unregister_dmac(&g2_dma_info);
193}
194
195subsys_initcall(g2_dma_init);
196module_exit(g2_dma_exit);
197
198MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");
199MODULE_DESCRIPTION("G2 bus DMA driver");
200MODULE_LICENSE("GPL");
201
