1 // SPDX-License-Identifier: GPL-2.0-only
3  * Copyright (C) 2015 VanguardiaSur - www.vanguardiasur.com.ar
10  * -----
12  * 1. Under stress-testing, it has been observed that the PCIe link
14  * to allow device hot-unplugging.
17  * including: scatter-gather, field and frame modes. However,
22  * Therefore, driver implements a dma_mode called 'memcpy' which
28  * a timer to limit the rate at which DMA is reset on DMA channels error.
41 #include "tw686x-regs.h"
50  * users wanting fine-grain control over the interrupt rate should
62 		return "memcpy";  in dma_mode_name()
86 		return -EINVAL;  in tw686x_dma_mode_set()
91 MODULE_PARM_DESC(dma_mode, "DMA operation mode (memcpy/contig/sg, default=memcpy)");
102 	dev->pending_dma_en &= ~BIT(channel);  in tw686x_disable_channel()
103 	dev->pending_dma_cmd &= ~BIT(channel);  in tw686x_disable_channel()
105 	/* Stop DMA if no channels are enabled */  in tw686x_disable_channel()
117 	dev->pending_dma_en |= dma_en | BIT(channel);  in tw686x_enable_channel()
118 	dev->pending_dma_cmd |= dma_cmd | DMA_CMD_ENABLE | BIT(channel);  in tw686x_enable_channel()
123  * channels "too fast" which makes some TW686x devices very
131 	spin_lock_irqsave(&dev->lock, flags);  in tw686x_dma_delay()
133 	reg_write(dev, DMA_CHANNEL_ENABLE, dev->pending_dma_en);  in tw686x_dma_delay()
134 	reg_write(dev, DMA_CMD, dev->pending_dma_cmd);  in tw686x_dma_delay()
135 	dev->pending_dma_en = 0;  in tw686x_dma_delay()
136 	dev->pending_dma_cmd = 0;  in tw686x_dma_delay()
138 	spin_unlock_irqrestore(&dev->lock, flags);  in tw686x_dma_delay()
152 	dev->pending_dma_en |= dma_en;  in tw686x_reset_channels()
153 	dev->pending_dma_cmd |= dma_cmd;  in tw686x_reset_channels()
155 	/* Disable the reset channels */  in tw686x_reset_channels()
159 		dev_dbg(&dev->pci_dev->dev, "reset: stopping DMA\n");  in tw686x_reset_channels()
181 		dev_dbg(&dev->pci_dev->dev,  in tw686x_irq()
182 			"DMA timeout. Resetting DMA for all channels\n");  in tw686x_irq()
187 	spin_lock_irqsave(&dev->lock, flags);  in tw686x_irq()
189 	spin_unlock_irqrestore(&dev->lock, flags);  in tw686x_irq()
196 	/* Mask of channels with signal and FIFO errors */  in tw686x_irq()
214 		spin_lock_irqsave(&dev->lock, flags);  in tw686x_irq()
216 		spin_unlock_irqrestore(&dev->lock, flags);  in tw686x_irq()
217 		mod_timer(&dev->dma_delay_timer,  in tw686x_irq()
231 		v4l2_ctrl_handler_free(&dev->video_channels[ch].ctrl_handler);  in tw686x_dev_release()
233 	v4l2_device_unregister(&dev->v4l2_dev);  in tw686x_dev_release()
235 	kfree(dev->audio_channels);  in tw686x_dev_release()
236 	kfree(dev->video_channels);  in tw686x_dev_release()
248 		return -ENOMEM;  in tw686x_probe()
249 	dev->type = pci_id->driver_data;  in tw686x_probe()
250 	dev->dma_mode = dma_mode;  in tw686x_probe()
251 	sprintf(dev->name, "tw%04X", pci_dev->device);  in tw686x_probe()
253 	dev->video_channels = kcalloc(max_channels(dev),  in tw686x_probe()
254 		sizeof(*dev->video_channels), GFP_KERNEL);  in tw686x_probe()
255 	if (!dev->video_channels) {  in tw686x_probe()
256 		err = -ENOMEM;  in tw686x_probe()
260 	dev->audio_channels = kcalloc(max_channels(dev),  in tw686x_probe()
261 		sizeof(*dev->audio_channels), GFP_KERNEL);  in tw686x_probe()
262 	if (!dev->audio_channels) {  in tw686x_probe()
263 		err = -ENOMEM;  in tw686x_probe()
267 	pr_info("%s: PCI %s, IRQ %d, MMIO 0x%lx (%s mode)\n", dev->name,  in tw686x_probe()
268 		pci_name(pci_dev), pci_dev->irq,  in tw686x_probe()
272 	dev->pci_dev = pci_dev;  in tw686x_probe()
274 		err = -EIO;  in tw686x_probe()
279 	err = dma_set_mask(&pci_dev->dev, DMA_BIT_MASK(32));  in tw686x_probe()
281 		dev_err(&pci_dev->dev, "32-bit PCI DMA not supported\n");  in tw686x_probe()
282 		err = -EIO;  in tw686x_probe()
286 	err = pci_request_regions(pci_dev, dev->name);  in tw686x_probe()
288 		dev_err(&pci_dev->dev, "unable to request PCI region\n");  in tw686x_probe()
292 	dev->mmio = pci_ioremap_bar(pci_dev, 0);  in tw686x_probe()
293 	if (!dev->mmio) {  in tw686x_probe()
294 		dev_err(&pci_dev->dev, "unable to remap PCI region\n");  in tw686x_probe()
295 		err = -ENOMEM;  in tw686x_probe()
316 	spin_lock_init(&dev->lock);  in tw686x_probe()
318 	timer_setup(&dev->dma_delay_timer, tw686x_dma_delay, 0);  in tw686x_probe()
325 	dev->v4l2_dev.release = tw686x_dev_release;  in tw686x_probe()
328 		dev_err(&pci_dev->dev, "can't register video\n");  in tw686x_probe()
334 		dev_warn(&pci_dev->dev, "can't register audio\n");  in tw686x_probe()
336 	err = request_irq(pci_dev->irq, tw686x_irq, IRQF_SHARED,  in tw686x_probe()
337 			  dev->name, dev);  in tw686x_probe()
339 		dev_err(&pci_dev->dev, "unable to request interrupt\n");  in tw686x_probe()
350 	pci_iounmap(pci_dev, dev->mmio);  in tw686x_probe()
356 	kfree(dev->audio_channels);  in tw686x_probe()
358 	kfree(dev->video_channels);  in tw686x_probe()
370 	 * which means we can kiss good-bye some resources.  in tw686x_remove()
372 	free_irq(pci_dev->irq, dev);  in tw686x_remove()
376 	del_timer_sync(&dev->dma_delay_timer);  in tw686x_remove()
378 	pci_iounmap(pci_dev, dev->mmio);  in tw686x_remove()
385 	 * the device sometimes hot-unplugs itself as the result of a PCIe  in tw686x_remove()
389 	spin_lock_irqsave(&dev->lock, flags);  in tw686x_remove()
390 	dev->pci_dev = NULL;  in tw686x_remove()
391 	spin_unlock_irqrestore(&dev->lock, flags);  in tw686x_remove()
397 	v4l2_device_put(&dev->v4l2_dev);  in tw686x_remove()
401  * On TW6864 and TW6868, all channels share the pair of video DMA SG tables,
402  * with 10-bit start_idx and end_idx determining start and end of frame buffer
404  * TW6868 with all its 8 channels would be problematic (only 127 SG entries per
405  * channel) but we support only 4 channels on this chip anyway (the first
406  * 4 channels are driven with internal video decoder, the other 4 would require
411  * (respectively 4 or 8-channel).
416 /* driver_data is number of A/V channels */
427 	 * TW6868 supports 8 A/V channels with an external TW2865 chip;