imx-dma.c 10.9 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
/*
 * drivers/dma/imx-dma.c
 *
 * This file contains a driver for the Freescale i.MX DMA engine
 * found on i.MX1/21/27
 *
 * Copyright 2010 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
 *
 * The code contained herein is licensed under the GNU General Public
 * License. You may obtain a copy of the GNU General Public License
 * Version 2 or later at the following locations:
 *
 * http://www.opensource.org/licenses/gpl-license.html
 * http://www.gnu.org/copyleft/gpl.html
 */
#include <linux/init.h>
17
#include <linux/module.h>
18 19 20 21 22 23 24 25 26
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/dmaengine.h>
27
#include <linux/module.h>
28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53

#include <asm/irq.h>
#include <mach/dma-v1.h>
#include <mach/hardware.h>

struct imxdma_channel {
	struct imxdma_engine		*imxdma;
	unsigned int			channel;
	unsigned int			imxdma_channel;

	enum dma_slave_buswidth		word_size;
	dma_addr_t			per_address;
	u32				watermark_level;
	struct dma_chan			chan;
	spinlock_t			lock;
	struct dma_async_tx_descriptor	desc;
	dma_cookie_t			last_completed;
	enum dma_status			status;
	int				dma_request;
	struct scatterlist		*sg_list;
};

#define MAX_DMA_CHANNELS 8

struct imxdma_engine {
	struct device			*dev;
54
	struct device_dma_parameters	dma_parms;
55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109
	struct dma_device		dma_device;
	struct imxdma_channel		channel[MAX_DMA_CHANNELS];
};

static struct imxdma_channel *to_imxdma_chan(struct dma_chan *chan)
{
	return container_of(chan, struct imxdma_channel, chan);
}

static void imxdma_handle(struct imxdma_channel *imxdmac)
{
	if (imxdmac->desc.callback)
		imxdmac->desc.callback(imxdmac->desc.callback_param);
	imxdmac->last_completed = imxdmac->desc.cookie;
}

static void imxdma_irq_handler(int channel, void *data)
{
	struct imxdma_channel *imxdmac = data;

	imxdmac->status = DMA_SUCCESS;
	imxdma_handle(imxdmac);
}

static void imxdma_err_handler(int channel, void *data, int error)
{
	struct imxdma_channel *imxdmac = data;

	imxdmac->status = DMA_ERROR;
	imxdma_handle(imxdmac);
}

static void imxdma_progression(int channel, void *data,
		struct scatterlist *sg)
{
	struct imxdma_channel *imxdmac = data;

	imxdmac->status = DMA_SUCCESS;
	imxdma_handle(imxdmac);
}

static int imxdma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
		unsigned long arg)
{
	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
	struct dma_slave_config *dmaengine_cfg = (void *)arg;
	int ret;
	unsigned int mode = 0;

	switch (cmd) {
	case DMA_TERMINATE_ALL:
		imxdmac->status = DMA_ERROR;
		imx_dma_disable(imxdmac->imxdma_channel);
		return 0;
	case DMA_SLAVE_CONFIG:
110
		if (dmaengine_cfg->direction == DMA_DEV_TO_MEM) {
111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139
			imxdmac->per_address = dmaengine_cfg->src_addr;
			imxdmac->watermark_level = dmaengine_cfg->src_maxburst;
			imxdmac->word_size = dmaengine_cfg->src_addr_width;
		} else {
			imxdmac->per_address = dmaengine_cfg->dst_addr;
			imxdmac->watermark_level = dmaengine_cfg->dst_maxburst;
			imxdmac->word_size = dmaengine_cfg->dst_addr_width;
		}

		switch (imxdmac->word_size) {
		case DMA_SLAVE_BUSWIDTH_1_BYTE:
			mode = IMX_DMA_MEMSIZE_8;
			break;
		case DMA_SLAVE_BUSWIDTH_2_BYTES:
			mode = IMX_DMA_MEMSIZE_16;
			break;
		default:
		case DMA_SLAVE_BUSWIDTH_4_BYTES:
			mode = IMX_DMA_MEMSIZE_32;
			break;
		}
		ret = imx_dma_config_channel(imxdmac->imxdma_channel,
				mode | IMX_DMA_TYPE_FIFO,
				IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR,
				imxdmac->dma_request, 1);

		if (ret)
			return ret;

140 141
		imx_dma_config_burstlen(imxdmac->imxdma_channel,
				imxdmac->watermark_level * imxdmac->word_size);
142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224

		return 0;
	default:
		return -ENOSYS;
	}

	return -EINVAL;
}

static enum dma_status imxdma_tx_status(struct dma_chan *chan,
					    dma_cookie_t cookie,
					    struct dma_tx_state *txstate)
{
	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
	dma_cookie_t last_used;
	enum dma_status ret;

	last_used = chan->cookie;

	ret = dma_async_is_complete(cookie, imxdmac->last_completed, last_used);
	dma_set_tx_state(txstate, imxdmac->last_completed, last_used, 0);

	return ret;
}

static dma_cookie_t imxdma_assign_cookie(struct imxdma_channel *imxdma)
{
	dma_cookie_t cookie = imxdma->chan.cookie;

	if (++cookie < 0)
		cookie = 1;

	imxdma->chan.cookie = cookie;
	imxdma->desc.cookie = cookie;

	return cookie;
}

static dma_cookie_t imxdma_tx_submit(struct dma_async_tx_descriptor *tx)
{
	struct imxdma_channel *imxdmac = to_imxdma_chan(tx->chan);
	dma_cookie_t cookie;

	spin_lock_irq(&imxdmac->lock);

	cookie = imxdma_assign_cookie(imxdmac);

	spin_unlock_irq(&imxdmac->lock);

	return cookie;
}

static int imxdma_alloc_chan_resources(struct dma_chan *chan)
{
	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
	struct imx_dma_data *data = chan->private;

	imxdmac->dma_request = data->dma_request;

	dma_async_tx_descriptor_init(&imxdmac->desc, chan);
	imxdmac->desc.tx_submit = imxdma_tx_submit;
	/* txd.flags will be overwritten in prep funcs */
	imxdmac->desc.flags = DMA_CTRL_ACK;

	imxdmac->status = DMA_SUCCESS;

	return 0;
}

static void imxdma_free_chan_resources(struct dma_chan *chan)
{
	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);

	imx_dma_disable(imxdmac->imxdma_channel);

	if (imxdmac->sg_list) {
		kfree(imxdmac->sg_list);
		imxdmac->sg_list = NULL;
	}
}

static struct dma_async_tx_descriptor *imxdma_prep_slave_sg(
		struct dma_chan *chan, struct scatterlist *sgl,
225
		unsigned int sg_len, enum dma_transfer_direction direction,
226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241
		unsigned long flags)
{
	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
	struct scatterlist *sg;
	int i, ret, dma_length = 0;
	unsigned int dmamode;

	if (imxdmac->status == DMA_IN_PROGRESS)
		return NULL;

	imxdmac->status = DMA_IN_PROGRESS;

	for_each_sg(sgl, sg, sg_len, i) {
		dma_length += sg->length;
	}

242
	if (direction == DMA_DEV_TO_MEM)
243 244 245 246
		dmamode = DMA_MODE_READ;
	else
		dmamode = DMA_MODE_WRITE;

247 248 249 250 251 252 253 254 255 256 257 258 259 260 261
	switch (imxdmac->word_size) {
	case DMA_SLAVE_BUSWIDTH_4_BYTES:
		if (sgl->length & 3 || sgl->dma_address & 3)
			return NULL;
		break;
	case DMA_SLAVE_BUSWIDTH_2_BYTES:
		if (sgl->length & 1 || sgl->dma_address & 1)
			return NULL;
		break;
	case DMA_SLAVE_BUSWIDTH_1_BYTE:
		break;
	default:
		return NULL;
	}

262 263 264 265 266 267 268 269 270 271
	ret = imx_dma_setup_sg(imxdmac->imxdma_channel, sgl, sg_len,
		 dma_length, imxdmac->per_address, dmamode);
	if (ret)
		return NULL;

	return &imxdmac->desc;
}

static struct dma_async_tx_descriptor *imxdma_prep_dma_cyclic(
		struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
272
		size_t period_len, enum dma_transfer_direction direction)
273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317
{
	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
	struct imxdma_engine *imxdma = imxdmac->imxdma;
	int i, ret;
	unsigned int periods = buf_len / period_len;
	unsigned int dmamode;

	dev_dbg(imxdma->dev, "%s channel: %d buf_len=%d period_len=%d\n",
			__func__, imxdmac->channel, buf_len, period_len);

	if (imxdmac->status == DMA_IN_PROGRESS)
		return NULL;
	imxdmac->status = DMA_IN_PROGRESS;

	ret = imx_dma_setup_progression_handler(imxdmac->imxdma_channel,
			imxdma_progression);
	if (ret) {
		dev_err(imxdma->dev, "Failed to setup the DMA handler\n");
		return NULL;
	}

	if (imxdmac->sg_list)
		kfree(imxdmac->sg_list);

	imxdmac->sg_list = kcalloc(periods + 1,
			sizeof(struct scatterlist), GFP_KERNEL);
	if (!imxdmac->sg_list)
		return NULL;

	sg_init_table(imxdmac->sg_list, periods);

	for (i = 0; i < periods; i++) {
		imxdmac->sg_list[i].page_link = 0;
		imxdmac->sg_list[i].offset = 0;
		imxdmac->sg_list[i].dma_address = dma_addr;
		imxdmac->sg_list[i].length = period_len;
		dma_addr += period_len;
	}

	/* close the loop */
	imxdmac->sg_list[periods].offset = 0;
	imxdmac->sg_list[periods].length = 0;
	imxdmac->sg_list[periods].page_link =
		((unsigned long)imxdmac->sg_list | 0x01) & ~0x02;

318
	if (direction == DMA_DEV_TO_MEM)
319 320 321 322 323 324 325 326 327 328 329 330 331 332
		dmamode = DMA_MODE_READ;
	else
		dmamode = DMA_MODE_WRITE;

	ret = imx_dma_setup_sg(imxdmac->imxdma_channel, imxdmac->sg_list, periods,
		 IMX_DMA_LENGTH_LOOP, imxdmac->per_address, dmamode);
	if (ret)
		return NULL;

	return &imxdmac->desc;
}

static void imxdma_issue_pending(struct dma_chan *chan)
{
333 334 335 336
	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);

	if (imxdmac->status == DMA_IN_PROGRESS)
		imx_dma_enable(imxdmac->imxdma_channel);
337 338 339 340 341 342 343 344 345 346 347 348 349
}

static int __init imxdma_probe(struct platform_device *pdev)
{
	struct imxdma_engine *imxdma;
	int ret, i;

	imxdma = kzalloc(sizeof(*imxdma), GFP_KERNEL);
	if (!imxdma)
		return -ENOMEM;

	INIT_LIST_HEAD(&imxdma->dma_device.channels);

350 351 352
	dma_cap_set(DMA_SLAVE, imxdma->dma_device.cap_mask);
	dma_cap_set(DMA_CYCLIC, imxdma->dma_device.cap_mask);

353 354 355 356 357 358
	/* Initialize channel parameters */
	for (i = 0; i < MAX_DMA_CHANNELS; i++) {
		struct imxdma_channel *imxdmac = &imxdma->channel[i];

		imxdmac->imxdma_channel = imx_dma_request_by_prio("dmaengine",
				DMA_PRIO_MEDIUM);
S
Sascha Hauer 已提交
359 360
		if ((int)imxdmac->channel < 0) {
			ret = -ENODEV;
361
			goto err_init;
S
Sascha Hauer 已提交
362
		}
363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389

		imx_dma_setup_handlers(imxdmac->imxdma_channel,
		       imxdma_irq_handler, imxdma_err_handler, imxdmac);

		imxdmac->imxdma = imxdma;
		spin_lock_init(&imxdmac->lock);

		imxdmac->chan.device = &imxdma->dma_device;
		imxdmac->channel = i;

		/* Add the channel to the DMAC list */
		list_add_tail(&imxdmac->chan.device_node, &imxdma->dma_device.channels);
	}

	imxdma->dev = &pdev->dev;
	imxdma->dma_device.dev = &pdev->dev;

	imxdma->dma_device.device_alloc_chan_resources = imxdma_alloc_chan_resources;
	imxdma->dma_device.device_free_chan_resources = imxdma_free_chan_resources;
	imxdma->dma_device.device_tx_status = imxdma_tx_status;
	imxdma->dma_device.device_prep_slave_sg = imxdma_prep_slave_sg;
	imxdma->dma_device.device_prep_dma_cyclic = imxdma_prep_dma_cyclic;
	imxdma->dma_device.device_control = imxdma_control;
	imxdma->dma_device.device_issue_pending = imxdma_issue_pending;

	platform_set_drvdata(pdev, imxdma);

390 391 392
	imxdma->dma_device.dev->dma_parms = &imxdma->dma_parms;
	dma_set_max_seg_size(imxdma->dma_device.dev, 0xffffff);

393 394 395 396 397 398 399 400 401
	ret = dma_async_device_register(&imxdma->dma_device);
	if (ret) {
		dev_err(&pdev->dev, "unable to register\n");
		goto err_init;
	}

	return 0;

err_init:
402
	while (--i >= 0) {
403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444
		struct imxdma_channel *imxdmac = &imxdma->channel[i];
		imx_dma_free(imxdmac->imxdma_channel);
	}

	kfree(imxdma);
	return ret;
}

static int __exit imxdma_remove(struct platform_device *pdev)
{
	struct imxdma_engine *imxdma = platform_get_drvdata(pdev);
	int i;

        dma_async_device_unregister(&imxdma->dma_device);

	for (i = 0; i < MAX_DMA_CHANNELS; i++) {
		struct imxdma_channel *imxdmac = &imxdma->channel[i];

		 imx_dma_free(imxdmac->imxdma_channel);
	}

        kfree(imxdma);

        return 0;
}

static struct platform_driver imxdma_driver = {
	.driver		= {
		.name	= "imx-dma",
	},
	.remove		= __exit_p(imxdma_remove),
};

static int __init imxdma_module_init(void)
{
	return platform_driver_probe(&imxdma_driver, imxdma_probe);
}
subsys_initcall(imxdma_module_init);

MODULE_AUTHOR("Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>");
MODULE_DESCRIPTION("i.MX dma driver");
MODULE_LICENSE("GPL");