2 * arch/sh/drivers/dma/dma-sh.c
4 * SuperH On-chip DMAC Support
6 * Copyright (C) 2000 Takashi YOSHII
7 * Copyright (C) 2003, 2004 Paul Mundt
8 * Copyright (C) 2005 Andriy Skulysh
10 * This file is subject to the terms and conditions of the GNU General Public
11 * License. See the file "COPYING" in the main directory of this archive
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/module.h>
17 #include <asm/dreamcast/dma.h>
22 static int dmte_irq_map[] = {
27 #if defined(CONFIG_CPU_SUBTYPE_SH7720) || \
28 defined(CONFIG_CPU_SUBTYPE_SH7751R) || \
29 defined(CONFIG_CPU_SUBTYPE_SH7760) || \
30 defined(CONFIG_CPU_SUBTYPE_SH7780)
34 #if defined(CONFIG_CPU_SUBTYPE_SH7751R) || \
35 defined(CONFIG_CPU_SUBTYPE_SH7760) || \
36 defined(CONFIG_CPU_SUBTYPE_SH7780)
42 static inline unsigned int get_dmte_irq(unsigned int chan)
45 if (chan < ARRAY_SIZE(dmte_irq_map))
46 irq = dmte_irq_map[chan];
51 * We determine the correct shift size based off of the CHCR transmit size
52 * for the given channel. Since we know that it will take:
54 * info->count >> ts_shift[transmit_size]
56 * iterations to complete the transfer.
58 static inline unsigned int calc_xmit_shift(struct dma_channel *chan)
60 u32 chcr = ctrl_inl(CHCR[chan->chan]);
62 return ts_shift[(chcr & CHCR_TS_MASK)>>CHCR_TS_SHIFT];
66 * The transfer end interrupt must read the chcr register to end the
67 * hardware interrupt active condition.
68 * Besides that it needs to waken any waiting process, which should handle
69 * setting up the next transfer.
71 static irqreturn_t dma_tei(int irq, void *dev_id)
73 struct dma_channel *chan = dev_id;
76 chcr = ctrl_inl(CHCR[chan->chan]);
78 if (!(chcr & CHCR_TE))
81 chcr &= ~(CHCR_IE | CHCR_DE);
82 ctrl_outl(chcr, CHCR[chan->chan]);
84 wake_up(&chan->wait_queue);
89 static int sh_dmac_request_dma(struct dma_channel *chan)
91 if (unlikely(!chan->flags & DMA_TEI_CAPABLE))
94 return request_irq(get_dmte_irq(chan->chan), dma_tei,
95 IRQF_DISABLED, chan->dev_id, chan);
98 static void sh_dmac_free_dma(struct dma_channel *chan)
100 free_irq(get_dmte_irq(chan->chan), chan);
104 sh_dmac_configure_channel(struct dma_channel *chan, unsigned long chcr)
107 chcr = RS_DUAL | CHCR_IE;
109 if (chcr & CHCR_IE) {
111 chan->flags |= DMA_TEI_CAPABLE;
113 chan->flags &= ~DMA_TEI_CAPABLE;
116 ctrl_outl(chcr, CHCR[chan->chan]);
118 chan->flags |= DMA_CONFIGURED;
122 static void sh_dmac_enable_dma(struct dma_channel *chan)
127 chcr = ctrl_inl(CHCR[chan->chan]);
130 if (chan->flags & DMA_TEI_CAPABLE)
133 ctrl_outl(chcr, CHCR[chan->chan]);
135 if (chan->flags & DMA_TEI_CAPABLE) {
136 irq = get_dmte_irq(chan->chan);
141 static void sh_dmac_disable_dma(struct dma_channel *chan)
146 if (chan->flags & DMA_TEI_CAPABLE) {
147 irq = get_dmte_irq(chan->chan);
151 chcr = ctrl_inl(CHCR[chan->chan]);
152 chcr &= ~(CHCR_DE | CHCR_TE | CHCR_IE);
153 ctrl_outl(chcr, CHCR[chan->chan]);
156 static int sh_dmac_xfer_dma(struct dma_channel *chan)
159 * If we haven't pre-configured the channel with special flags, use
162 if (unlikely(!(chan->flags & DMA_CONFIGURED)))
163 sh_dmac_configure_channel(chan, 0);
165 sh_dmac_disable_dma(chan);
168 * Single-address mode usage note!
170 * It's important that we don't accidentally write any value to SAR/DAR
171 * (this includes 0) that hasn't been directly specified by the user if
172 * we're in single-address mode.
174 * In this case, only one address can be defined, anything else will
175 * result in a DMA address error interrupt (at least on the SH-4),
176 * which will subsequently halt the transfer.
178 * Channel 2 on the Dreamcast is a special case, as this is used for
179 * cascading to the PVR2 DMAC. In this case, we still need to write
180 * SAR and DAR, regardless of value, in order for cascading to work.
182 if (chan->sar || (mach_is_dreamcast() &&
183 chan->chan == PVR2_CASCADE_CHAN))
184 ctrl_outl(chan->sar, SAR[chan->chan]);
185 if (chan->dar || (mach_is_dreamcast() &&
186 chan->chan == PVR2_CASCADE_CHAN))
187 ctrl_outl(chan->dar, DAR[chan->chan]);
189 ctrl_outl(chan->count >> calc_xmit_shift(chan), DMATCR[chan->chan]);
191 sh_dmac_enable_dma(chan);
196 static int sh_dmac_get_dma_residue(struct dma_channel *chan)
198 if (!(ctrl_inl(CHCR[chan->chan]) & CHCR_DE))
201 return ctrl_inl(DMATCR[chan->chan]) << calc_xmit_shift(chan);
204 #if defined(CONFIG_CPU_SUBTYPE_SH7720) || \
205 defined(CONFIG_CPU_SUBTYPE_SH7780)
206 #define dmaor_read_reg() ctrl_inw(DMAOR)
207 #define dmaor_write_reg(data) ctrl_outw(data, DMAOR)
209 #define dmaor_read_reg() ctrl_inl(DMAOR)
210 #define dmaor_write_reg(data) ctrl_outl(data, DMAOR)
213 static inline int dmaor_reset(void)
215 unsigned long dmaor = dmaor_read_reg();
217 /* Try to clear the error flags first, incase they are set */
218 dmaor &= ~(DMAOR_NMIF | DMAOR_AE);
219 dmaor_write_reg(dmaor);
222 dmaor_write_reg(dmaor);
224 /* See if we got an error again */
225 if ((dmaor_read_reg() & (DMAOR_AE | DMAOR_NMIF))) {
226 printk(KERN_ERR "dma-sh: Can't initialize DMAOR.\n");
233 #if defined(CONFIG_CPU_SH4)
234 static irqreturn_t dma_err(int irq, void *dummy)
243 static struct dma_ops sh_dmac_ops = {
244 .request = sh_dmac_request_dma,
245 .free = sh_dmac_free_dma,
246 .get_residue = sh_dmac_get_dma_residue,
247 .xfer = sh_dmac_xfer_dma,
248 .configure = sh_dmac_configure_channel,
251 static struct dma_info sh_dmac_info = {
253 .nr_channels = CONFIG_NR_ONCHIP_DMA_CHANNELS,
255 .flags = DMAC_CHANNELS_TEI_CAPABLE,
258 static int __init sh_dmac_init(void)
260 struct dma_info *info = &sh_dmac_info;
263 #ifdef CONFIG_CPU_SH4
264 i = request_irq(DMAE_IRQ, dma_err, IRQF_DISABLED, "DMAC Address Error", 0);
270 * Initialize DMAOR, and clean up any error flags that may have
274 if (unlikely(i != 0))
277 return register_dmac(info);
280 static void __exit sh_dmac_exit(void)
282 #ifdef CONFIG_CPU_SH4
283 free_irq(DMAE_IRQ, 0);
285 unregister_dmac(&sh_dmac_info);
288 subsys_initcall(sh_dmac_init);
289 module_exit(sh_dmac_exit);
291 MODULE_AUTHOR("Takashi YOSHII, Paul Mundt, Andriy Skulysh");
292 MODULE_DESCRIPTION("SuperH On-Chip DMAC Support");
293 MODULE_LICENSE("GPL");