2 * This program is free software; you can redistribute it and/or modify it
3 * under the terms of the GNU General Public License version 2 as published
4 * by the Free Software Foundation.
6 * This program is distributed in the hope that it will be useful,
7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
9 * GNU General Public License for more details.
11 * You should have received a copy of the GNU General Public License
12 * along with this program; if not, write to the Free Software
13 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
15 * Copyright (C) 2011 John Crispin <john@phrozen.org>
18 #include <linux/init.h>
19 #include <linux/platform_device.h>
21 #include <linux/dma-mapping.h>
22 #include <linux/export.h>
23 #include <linux/spinlock.h>
24 #include <linux/clk.h>
25 #include <linux/err.h>
27 #include <lantiq_soc.h>
30 #define LTQ_DMA_ID 0x08
31 #define LTQ_DMA_CTRL 0x10
32 #define LTQ_DMA_CPOLL 0x14
33 #define LTQ_DMA_CS 0x18
34 #define LTQ_DMA_CCTRL 0x1C
35 #define LTQ_DMA_CDBA 0x20
36 #define LTQ_DMA_CDLEN 0x24
37 #define LTQ_DMA_CIS 0x28
38 #define LTQ_DMA_CIE 0x2C
39 #define LTQ_DMA_PS 0x40
40 #define LTQ_DMA_PCTRL 0x44
41 #define LTQ_DMA_IRNEN 0xf4
43 #define DMA_DESCPT BIT(3) /* descriptor complete irq */
44 #define DMA_TX BIT(8) /* TX channel direction */
45 #define DMA_CHAN_ON BIT(0) /* channel on / off bit */
46 #define DMA_PDEN BIT(6) /* enable packet drop */
47 #define DMA_CHAN_RST BIT(1) /* channel on / off bit */
48 #define DMA_RESET BIT(0) /* channel on / off bit */
49 #define DMA_IRQ_ACK 0x7e /* IRQ status register */
50 #define DMA_POLL BIT(31) /* turn on channel polling */
51 #define DMA_CLK_DIV4 BIT(6) /* polling clock divider */
52 #define DMA_2W_BURST BIT(1) /* 2 word burst length */
53 #define DMA_MAX_CHANNEL 20 /* the soc has 20 channels */
54 #define DMA_ETOP_ENDIANNESS (0xf << 8) /* endianness swap etop channels */
55 #define DMA_WEIGHT (BIT(17) | BIT(16)) /* default channel wheight */
57 #define ltq_dma_r32(x) ltq_r32(ltq_dma_membase + (x))
58 #define ltq_dma_w32(x, y) ltq_w32(x, ltq_dma_membase + (y))
59 #define ltq_dma_w32_mask(x, y, z) ltq_w32_mask(x, y, \
60 ltq_dma_membase + (z))
62 static void __iomem *ltq_dma_membase;
63 static DEFINE_SPINLOCK(ltq_dma_lock);
66 ltq_dma_enable_irq(struct ltq_dma_channel *ch)
70 spin_lock_irqsave(<q_dma_lock, flags);
71 ltq_dma_w32(ch->nr, LTQ_DMA_CS);
72 ltq_dma_w32_mask(0, 1 << ch->nr, LTQ_DMA_IRNEN);
73 spin_unlock_irqrestore(<q_dma_lock, flags);
75 EXPORT_SYMBOL_GPL(ltq_dma_enable_irq);
78 ltq_dma_disable_irq(struct ltq_dma_channel *ch)
82 spin_lock_irqsave(<q_dma_lock, flags);
83 ltq_dma_w32(ch->nr, LTQ_DMA_CS);
84 ltq_dma_w32_mask(1 << ch->nr, 0, LTQ_DMA_IRNEN);
85 spin_unlock_irqrestore(<q_dma_lock, flags);
87 EXPORT_SYMBOL_GPL(ltq_dma_disable_irq);
90 ltq_dma_ack_irq(struct ltq_dma_channel *ch)
94 spin_lock_irqsave(<q_dma_lock, flags);
95 ltq_dma_w32(ch->nr, LTQ_DMA_CS);
96 ltq_dma_w32(DMA_IRQ_ACK, LTQ_DMA_CIS);
97 spin_unlock_irqrestore(<q_dma_lock, flags);
99 EXPORT_SYMBOL_GPL(ltq_dma_ack_irq);
102 ltq_dma_open(struct ltq_dma_channel *ch)
106 spin_lock_irqsave(<q_dma_lock, flag);
107 ltq_dma_w32(ch->nr, LTQ_DMA_CS);
108 ltq_dma_w32_mask(0, DMA_CHAN_ON, LTQ_DMA_CCTRL);
109 spin_unlock_irqrestore(<q_dma_lock, flag);
111 EXPORT_SYMBOL_GPL(ltq_dma_open);
114 ltq_dma_close(struct ltq_dma_channel *ch)
118 spin_lock_irqsave(<q_dma_lock, flag);
119 ltq_dma_w32(ch->nr, LTQ_DMA_CS);
120 ltq_dma_w32_mask(DMA_CHAN_ON, 0, LTQ_DMA_CCTRL);
121 ltq_dma_w32_mask(1 << ch->nr, 0, LTQ_DMA_IRNEN);
122 spin_unlock_irqrestore(<q_dma_lock, flag);
124 EXPORT_SYMBOL_GPL(ltq_dma_close);
127 ltq_dma_alloc(struct ltq_dma_channel *ch)
132 ch->desc_base = dma_zalloc_coherent(ch->dev,
133 LTQ_DESC_NUM * LTQ_DESC_SIZE,
134 &ch->phys, GFP_ATOMIC);
136 spin_lock_irqsave(<q_dma_lock, flags);
137 ltq_dma_w32(ch->nr, LTQ_DMA_CS);
138 ltq_dma_w32(ch->phys, LTQ_DMA_CDBA);
139 ltq_dma_w32(LTQ_DESC_NUM, LTQ_DMA_CDLEN);
140 ltq_dma_w32_mask(DMA_CHAN_ON, 0, LTQ_DMA_CCTRL);
142 ltq_dma_w32_mask(0, DMA_CHAN_RST, LTQ_DMA_CCTRL);
143 while (ltq_dma_r32(LTQ_DMA_CCTRL) & DMA_CHAN_RST)
145 spin_unlock_irqrestore(<q_dma_lock, flags);
149 ltq_dma_alloc_tx(struct ltq_dma_channel *ch)
155 spin_lock_irqsave(<q_dma_lock, flags);
156 ltq_dma_w32(DMA_DESCPT, LTQ_DMA_CIE);
157 ltq_dma_w32_mask(0, 1 << ch->nr, LTQ_DMA_IRNEN);
158 ltq_dma_w32(DMA_WEIGHT | DMA_TX, LTQ_DMA_CCTRL);
159 spin_unlock_irqrestore(<q_dma_lock, flags);
161 EXPORT_SYMBOL_GPL(ltq_dma_alloc_tx);
164 ltq_dma_alloc_rx(struct ltq_dma_channel *ch)
170 spin_lock_irqsave(<q_dma_lock, flags);
171 ltq_dma_w32(DMA_DESCPT, LTQ_DMA_CIE);
172 ltq_dma_w32_mask(0, 1 << ch->nr, LTQ_DMA_IRNEN);
173 ltq_dma_w32(DMA_WEIGHT, LTQ_DMA_CCTRL);
174 spin_unlock_irqrestore(<q_dma_lock, flags);
176 EXPORT_SYMBOL_GPL(ltq_dma_alloc_rx);
179 ltq_dma_free(struct ltq_dma_channel *ch)
184 dma_free_coherent(ch->dev, LTQ_DESC_NUM * LTQ_DESC_SIZE,
185 ch->desc_base, ch->phys);
187 EXPORT_SYMBOL_GPL(ltq_dma_free);
190 ltq_dma_init_port(int p)
192 ltq_dma_w32(p, LTQ_DMA_PS);
196 * Tell the DMA engine to swap the endianness of data frames and
197 * drop packets if the channel arbitration fails.
199 ltq_dma_w32_mask(0, DMA_ETOP_ENDIANNESS | DMA_PDEN,
204 ltq_dma_w32((DMA_2W_BURST << 4) | (DMA_2W_BURST << 2),
212 EXPORT_SYMBOL_GPL(ltq_dma_init_port);
215 ltq_dma_init(struct platform_device *pdev)
218 struct resource *res;
222 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
223 ltq_dma_membase = devm_ioremap_resource(&pdev->dev, res);
224 if (IS_ERR(ltq_dma_membase))
225 panic("Failed to remap dma resource");
227 /* power up and reset the dma engine */
228 clk = clk_get(&pdev->dev, NULL);
230 panic("Failed to get dma clock");
233 ltq_dma_w32_mask(0, DMA_RESET, LTQ_DMA_CTRL);
235 /* disable all interrupts */
236 ltq_dma_w32(0, LTQ_DMA_IRNEN);
238 /* reset/configure each channel */
239 for (i = 0; i < DMA_MAX_CHANNEL; i++) {
240 ltq_dma_w32(i, LTQ_DMA_CS);
241 ltq_dma_w32(DMA_CHAN_RST, LTQ_DMA_CCTRL);
242 ltq_dma_w32(DMA_POLL | DMA_CLK_DIV4, LTQ_DMA_CPOLL);
243 ltq_dma_w32_mask(DMA_CHAN_ON, 0, LTQ_DMA_CCTRL);
246 id = ltq_dma_r32(LTQ_DMA_ID);
248 "Init done - hw rev: %X, ports: %d, channels: %d\n",
249 id & 0x1f, (id >> 16) & 0xf, id >> 20);
254 static const struct of_device_id dma_match[] = {
255 { .compatible = "lantiq,dma-xway" },
259 static struct platform_driver dma_driver = {
260 .probe = ltq_dma_init,
263 .of_match_table = dma_match,
270 return platform_driver_register(&dma_driver);
273 postcore_initcall(dma_init);