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Diffstat (limited to 'arch/sh/drivers/dma/dma-sh.c')
-rw-r--r-- | arch/sh/drivers/dma/dma-sh.c | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/arch/sh/drivers/dma/dma-sh.c b/arch/sh/drivers/dma/dma-sh.c new file mode 100644 index 000000000000..31dacd4444b2 --- /dev/null +++ b/arch/sh/drivers/dma/dma-sh.c | |||
@@ -0,0 +1,267 @@ | |||
1 | /* | ||
2 | * arch/sh/drivers/dma/dma-sh.c | ||
3 | * | ||
4 | * SuperH On-chip DMAC Support | ||
5 | * | ||
6 | * Copyright (C) 2000 Takashi YOSHII | ||
7 | * Copyright (C) 2003, 2004 Paul Mundt | ||
8 | * | ||
9 | * This file is subject to the terms and conditions of the GNU General Public | ||
10 | * License. See the file "COPYING" in the main directory of this archive | ||
11 | * for more details. | ||
12 | */ | ||
13 | |||
14 | #include <linux/config.h> | ||
15 | #include <linux/init.h> | ||
16 | #include <linux/irq.h> | ||
17 | #include <linux/interrupt.h> | ||
18 | #include <linux/module.h> | ||
19 | #include <asm/signal.h> | ||
20 | #include <asm/irq.h> | ||
21 | #include <asm/dma.h> | ||
22 | #include <asm/io.h> | ||
23 | #include "dma-sh.h" | ||
24 | |||
25 | /* | ||
26 | * The SuperH DMAC supports a number of transmit sizes, we list them here, | ||
27 | * with their respective values as they appear in the CHCR registers. | ||
28 | * | ||
29 | * Defaults to a 64-bit transfer size. | ||
30 | */ | ||
31 | enum { | ||
32 | XMIT_SZ_64BIT, | ||
33 | XMIT_SZ_8BIT, | ||
34 | XMIT_SZ_16BIT, | ||
35 | XMIT_SZ_32BIT, | ||
36 | XMIT_SZ_256BIT, | ||
37 | }; | ||
38 | |||
39 | /* | ||
40 | * The DMA count is defined as the number of bytes to transfer. | ||
41 | */ | ||
42 | static unsigned int ts_shift[] = { | ||
43 | [XMIT_SZ_64BIT] = 3, | ||
44 | [XMIT_SZ_8BIT] = 0, | ||
45 | [XMIT_SZ_16BIT] = 1, | ||
46 | [XMIT_SZ_32BIT] = 2, | ||
47 | [XMIT_SZ_256BIT] = 5, | ||
48 | }; | ||
49 | |||
50 | static inline unsigned int get_dmte_irq(unsigned int chan) | ||
51 | { | ||
52 | unsigned int irq; | ||
53 | |||
54 | /* | ||
55 | * Normally we could just do DMTE0_IRQ + chan outright, though in the | ||
56 | * case of the 7751R, the DMTE IRQs for channels > 4 start right above | ||
57 | * the SCIF | ||
58 | */ | ||
59 | |||
60 | if (chan < 4) { | ||
61 | irq = DMTE0_IRQ + chan; | ||
62 | } else { | ||
63 | irq = DMTE4_IRQ + chan - 4; | ||
64 | } | ||
65 | |||
66 | return irq; | ||
67 | } | ||
68 | |||
69 | /* | ||
70 | * We determine the correct shift size based off of the CHCR transmit size | ||
71 | * for the given channel. Since we know that it will take: | ||
72 | * | ||
73 | * info->count >> ts_shift[transmit_size] | ||
74 | * | ||
75 | * iterations to complete the transfer. | ||
76 | */ | ||
77 | static inline unsigned int calc_xmit_shift(struct dma_channel *chan) | ||
78 | { | ||
79 | u32 chcr = ctrl_inl(CHCR[chan->chan]); | ||
80 | |||
81 | chcr >>= 4; | ||
82 | |||
83 | return ts_shift[chcr & 0x0007]; | ||
84 | } | ||
85 | |||
86 | /* | ||
87 | * The transfer end interrupt must read the chcr register to end the | ||
88 | * hardware interrupt active condition. | ||
89 | * Besides that it needs to waken any waiting process, which should handle | ||
90 | * setting up the next transfer. | ||
91 | */ | ||
92 | static irqreturn_t dma_tei(int irq, void *dev_id, struct pt_regs *regs) | ||
93 | { | ||
94 | struct dma_channel *chan = (struct dma_channel *)dev_id; | ||
95 | u32 chcr; | ||
96 | |||
97 | chcr = ctrl_inl(CHCR[chan->chan]); | ||
98 | |||
99 | if (!(chcr & CHCR_TE)) | ||
100 | return IRQ_NONE; | ||
101 | |||
102 | chcr &= ~(CHCR_IE | CHCR_DE); | ||
103 | ctrl_outl(chcr, CHCR[chan->chan]); | ||
104 | |||
105 | wake_up(&chan->wait_queue); | ||
106 | |||
107 | return IRQ_HANDLED; | ||
108 | } | ||
109 | |||
110 | static int sh_dmac_request_dma(struct dma_channel *chan) | ||
111 | { | ||
112 | return request_irq(get_dmte_irq(chan->chan), dma_tei, | ||
113 | SA_INTERRUPT, "DMAC Transfer End", chan); | ||
114 | } | ||
115 | |||
116 | static void sh_dmac_free_dma(struct dma_channel *chan) | ||
117 | { | ||
118 | free_irq(get_dmte_irq(chan->chan), chan); | ||
119 | } | ||
120 | |||
121 | static void sh_dmac_configure_channel(struct dma_channel *chan, unsigned long chcr) | ||
122 | { | ||
123 | if (!chcr) | ||
124 | chcr = RS_DUAL; | ||
125 | |||
126 | ctrl_outl(chcr, CHCR[chan->chan]); | ||
127 | |||
128 | chan->flags |= DMA_CONFIGURED; | ||
129 | } | ||
130 | |||
131 | static void sh_dmac_enable_dma(struct dma_channel *chan) | ||
132 | { | ||
133 | int irq = get_dmte_irq(chan->chan); | ||
134 | u32 chcr; | ||
135 | |||
136 | chcr = ctrl_inl(CHCR[chan->chan]); | ||
137 | chcr |= CHCR_DE | CHCR_IE; | ||
138 | ctrl_outl(chcr, CHCR[chan->chan]); | ||
139 | |||
140 | enable_irq(irq); | ||
141 | } | ||
142 | |||
143 | static void sh_dmac_disable_dma(struct dma_channel *chan) | ||
144 | { | ||
145 | int irq = get_dmte_irq(chan->chan); | ||
146 | u32 chcr; | ||
147 | |||
148 | disable_irq(irq); | ||
149 | |||
150 | chcr = ctrl_inl(CHCR[chan->chan]); | ||
151 | chcr &= ~(CHCR_DE | CHCR_TE | CHCR_IE); | ||
152 | ctrl_outl(chcr, CHCR[chan->chan]); | ||
153 | } | ||
154 | |||
155 | static int sh_dmac_xfer_dma(struct dma_channel *chan) | ||
156 | { | ||
157 | /* | ||
158 | * If we haven't pre-configured the channel with special flags, use | ||
159 | * the defaults. | ||
160 | */ | ||
161 | if (!(chan->flags & DMA_CONFIGURED)) | ||
162 | sh_dmac_configure_channel(chan, 0); | ||
163 | |||
164 | sh_dmac_disable_dma(chan); | ||
165 | |||
166 | /* | ||
167 | * Single-address mode usage note! | ||
168 | * | ||
169 | * It's important that we don't accidentally write any value to SAR/DAR | ||
170 | * (this includes 0) that hasn't been directly specified by the user if | ||
171 | * we're in single-address mode. | ||
172 | * | ||
173 | * In this case, only one address can be defined, anything else will | ||
174 | * result in a DMA address error interrupt (at least on the SH-4), | ||
175 | * which will subsequently halt the transfer. | ||
176 | * | ||
177 | * Channel 2 on the Dreamcast is a special case, as this is used for | ||
178 | * cascading to the PVR2 DMAC. In this case, we still need to write | ||
179 | * SAR and DAR, regardless of value, in order for cascading to work. | ||
180 | */ | ||
181 | if (chan->sar || (mach_is_dreamcast() && chan->chan == 2)) | ||
182 | ctrl_outl(chan->sar, SAR[chan->chan]); | ||
183 | if (chan->dar || (mach_is_dreamcast() && chan->chan == 2)) | ||
184 | ctrl_outl(chan->dar, DAR[chan->chan]); | ||
185 | |||
186 | ctrl_outl(chan->count >> calc_xmit_shift(chan), DMATCR[chan->chan]); | ||
187 | |||
188 | sh_dmac_enable_dma(chan); | ||
189 | |||
190 | return 0; | ||
191 | } | ||
192 | |||
193 | static int sh_dmac_get_dma_residue(struct dma_channel *chan) | ||
194 | { | ||
195 | if (!(ctrl_inl(CHCR[chan->chan]) & CHCR_DE)) | ||
196 | return 0; | ||
197 | |||
198 | return ctrl_inl(DMATCR[chan->chan]) << calc_xmit_shift(chan); | ||
199 | } | ||
200 | |||
201 | #if defined(CONFIG_CPU_SH4) | ||
202 | static irqreturn_t dma_err(int irq, void *dev_id, struct pt_regs *regs) | ||
203 | { | ||
204 | unsigned long dmaor = ctrl_inl(DMAOR); | ||
205 | |||
206 | printk("DMAE: DMAOR=%lx\n", dmaor); | ||
207 | |||
208 | ctrl_outl(ctrl_inl(DMAOR)&~DMAOR_NMIF, DMAOR); | ||
209 | ctrl_outl(ctrl_inl(DMAOR)&~DMAOR_AE, DMAOR); | ||
210 | ctrl_outl(ctrl_inl(DMAOR)|DMAOR_DME, DMAOR); | ||
211 | |||
212 | disable_irq(irq); | ||
213 | |||
214 | return IRQ_HANDLED; | ||
215 | } | ||
216 | #endif | ||
217 | |||
218 | static struct dma_ops sh_dmac_ops = { | ||
219 | .request = sh_dmac_request_dma, | ||
220 | .free = sh_dmac_free_dma, | ||
221 | .get_residue = sh_dmac_get_dma_residue, | ||
222 | .xfer = sh_dmac_xfer_dma, | ||
223 | .configure = sh_dmac_configure_channel, | ||
224 | }; | ||
225 | |||
226 | static struct dma_info sh_dmac_info = { | ||
227 | .name = "SuperH DMAC", | ||
228 | .nr_channels = 4, | ||
229 | .ops = &sh_dmac_ops, | ||
230 | .flags = DMAC_CHANNELS_TEI_CAPABLE, | ||
231 | }; | ||
232 | |||
233 | static int __init sh_dmac_init(void) | ||
234 | { | ||
235 | struct dma_info *info = &sh_dmac_info; | ||
236 | int i; | ||
237 | |||
238 | #ifdef CONFIG_CPU_SH4 | ||
239 | make_ipr_irq(DMAE_IRQ, DMA_IPR_ADDR, DMA_IPR_POS, DMA_PRIORITY); | ||
240 | i = request_irq(DMAE_IRQ, dma_err, SA_INTERRUPT, "DMAC Address Error", 0); | ||
241 | if (i < 0) | ||
242 | return i; | ||
243 | #endif | ||
244 | |||
245 | for (i = 0; i < info->nr_channels; i++) { | ||
246 | int irq = get_dmte_irq(i); | ||
247 | |||
248 | make_ipr_irq(irq, DMA_IPR_ADDR, DMA_IPR_POS, DMA_PRIORITY); | ||
249 | } | ||
250 | |||
251 | ctrl_outl(0x8000 | DMAOR_DME, DMAOR); | ||
252 | |||
253 | return register_dmac(info); | ||
254 | } | ||
255 | |||
256 | static void __exit sh_dmac_exit(void) | ||
257 | { | ||
258 | #ifdef CONFIG_CPU_SH4 | ||
259 | free_irq(DMAE_IRQ, 0); | ||
260 | #endif | ||
261 | } | ||
262 | |||
263 | subsys_initcall(sh_dmac_init); | ||
264 | module_exit(sh_dmac_exit); | ||
265 | |||
266 | MODULE_LICENSE("GPL"); | ||
267 | |||