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451 lines
12 KiB
451 lines
12 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Copyright (C) 2015 VanguardiaSur - www.vanguardiasur.com.ar |
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* |
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* Based on original driver by Krzysztof Ha?asa: |
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* Copyright (C) 2015 Industrial Research Institute for Automation |
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* and Measurements PIAP |
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* |
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* Notes |
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* ----- |
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* |
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* 1. Under stress-testing, it has been observed that the PCIe link |
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* goes down, without reason. Therefore, the driver takes special care |
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* to allow device hot-unplugging. |
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* |
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* 2. TW686X devices are capable of setting a few different DMA modes, |
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* including: scatter-gather, field and frame modes. However, |
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* under stress testings it has been found that the machine can |
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* freeze completely if DMA registers are programmed while streaming |
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* is active. |
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* |
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* Therefore, driver implements a dma_mode called 'memcpy' which |
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* avoids cycling the DMA buffers, and insteads allocates extra DMA buffers |
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* and then copies into vmalloc'ed user buffers. |
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* |
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* In addition to this, when streaming is on, the driver tries to access |
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* hardware registers as infrequently as possible. This is done by using |
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* a timer to limit the rate at which DMA is reset on DMA channels error. |
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*/ |
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#include <linux/init.h> |
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#include <linux/interrupt.h> |
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#include <linux/delay.h> |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/pci_ids.h> |
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#include <linux/slab.h> |
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#include <linux/timer.h> |
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#include "tw686x.h" |
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#include "tw686x-regs.h" |
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/* |
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* This module parameter allows to control the DMA_TIMER_INTERVAL value. |
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* The DMA_TIMER_INTERVAL register controls the minimum DMA interrupt |
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* time span (iow, the maximum DMA interrupt rate) thus allowing for |
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* IRQ coalescing. |
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* |
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* The chip datasheet does not mention a time unit for this value, so |
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* users wanting fine-grain control over the interrupt rate should |
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* determine the desired value through testing. |
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*/ |
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static u32 dma_interval = 0x00098968; |
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module_param(dma_interval, int, 0444); |
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MODULE_PARM_DESC(dma_interval, "Minimum time span for DMA interrupting host"); |
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static unsigned int dma_mode = TW686X_DMA_MODE_MEMCPY; |
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static const char *dma_mode_name(unsigned int mode) |
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{ |
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switch (mode) { |
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case TW686X_DMA_MODE_MEMCPY: |
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return "memcpy"; |
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case TW686X_DMA_MODE_CONTIG: |
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return "contig"; |
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case TW686X_DMA_MODE_SG: |
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return "sg"; |
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default: |
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return "unknown"; |
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} |
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} |
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static int tw686x_dma_mode_get(char *buffer, const struct kernel_param *kp) |
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{ |
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return sprintf(buffer, "%s", dma_mode_name(dma_mode)); |
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} |
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static int tw686x_dma_mode_set(const char *val, const struct kernel_param *kp) |
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{ |
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if (!strcasecmp(val, dma_mode_name(TW686X_DMA_MODE_MEMCPY))) |
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dma_mode = TW686X_DMA_MODE_MEMCPY; |
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else if (!strcasecmp(val, dma_mode_name(TW686X_DMA_MODE_CONTIG))) |
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dma_mode = TW686X_DMA_MODE_CONTIG; |
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else if (!strcasecmp(val, dma_mode_name(TW686X_DMA_MODE_SG))) |
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dma_mode = TW686X_DMA_MODE_SG; |
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else |
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return -EINVAL; |
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return 0; |
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} |
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module_param_call(dma_mode, tw686x_dma_mode_set, tw686x_dma_mode_get, |
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&dma_mode, S_IRUGO|S_IWUSR); |
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MODULE_PARM_DESC(dma_mode, "DMA operation mode (memcpy/contig/sg, default=memcpy)"); |
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void tw686x_disable_channel(struct tw686x_dev *dev, unsigned int channel) |
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{ |
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u32 dma_en = reg_read(dev, DMA_CHANNEL_ENABLE); |
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u32 dma_cmd = reg_read(dev, DMA_CMD); |
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dma_en &= ~BIT(channel); |
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dma_cmd &= ~BIT(channel); |
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/* Must remove it from pending too */ |
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dev->pending_dma_en &= ~BIT(channel); |
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dev->pending_dma_cmd &= ~BIT(channel); |
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/* Stop DMA if no channels are enabled */ |
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if (!dma_en) |
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dma_cmd = 0; |
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reg_write(dev, DMA_CHANNEL_ENABLE, dma_en); |
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reg_write(dev, DMA_CMD, dma_cmd); |
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} |
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void tw686x_enable_channel(struct tw686x_dev *dev, unsigned int channel) |
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{ |
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u32 dma_en = reg_read(dev, DMA_CHANNEL_ENABLE); |
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u32 dma_cmd = reg_read(dev, DMA_CMD); |
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dev->pending_dma_en |= dma_en | BIT(channel); |
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dev->pending_dma_cmd |= dma_cmd | DMA_CMD_ENABLE | BIT(channel); |
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} |
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/* |
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* The purpose of this awful hack is to avoid enabling the DMA |
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* channels "too fast" which makes some TW686x devices very |
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* angry and freeze the CPU (see note 1). |
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*/ |
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static void tw686x_dma_delay(struct timer_list *t) |
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{ |
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struct tw686x_dev *dev = from_timer(dev, t, dma_delay_timer); |
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unsigned long flags; |
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spin_lock_irqsave(&dev->lock, flags); |
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reg_write(dev, DMA_CHANNEL_ENABLE, dev->pending_dma_en); |
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reg_write(dev, DMA_CMD, dev->pending_dma_cmd); |
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dev->pending_dma_en = 0; |
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dev->pending_dma_cmd = 0; |
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spin_unlock_irqrestore(&dev->lock, flags); |
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} |
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static void tw686x_reset_channels(struct tw686x_dev *dev, unsigned int ch_mask) |
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{ |
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u32 dma_en, dma_cmd; |
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dma_en = reg_read(dev, DMA_CHANNEL_ENABLE); |
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dma_cmd = reg_read(dev, DMA_CMD); |
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/* |
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* Save pending register status, the timer will |
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* restore them. |
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*/ |
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dev->pending_dma_en |= dma_en; |
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dev->pending_dma_cmd |= dma_cmd; |
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/* Disable the reset channels */ |
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reg_write(dev, DMA_CHANNEL_ENABLE, dma_en & ~ch_mask); |
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if ((dma_en & ~ch_mask) == 0) { |
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dev_dbg(&dev->pci_dev->dev, "reset: stopping DMA\n"); |
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dma_cmd &= ~DMA_CMD_ENABLE; |
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} |
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reg_write(dev, DMA_CMD, dma_cmd & ~ch_mask); |
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} |
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static irqreturn_t tw686x_irq(int irq, void *dev_id) |
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{ |
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struct tw686x_dev *dev = (struct tw686x_dev *)dev_id; |
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unsigned int video_requests, audio_requests, reset_ch; |
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u32 fifo_status, fifo_signal, fifo_ov, fifo_bad, fifo_errors; |
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u32 int_status, dma_en, video_en, pb_status; |
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unsigned long flags; |
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int_status = reg_read(dev, INT_STATUS); /* cleared on read */ |
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fifo_status = reg_read(dev, VIDEO_FIFO_STATUS); |
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/* INT_STATUS does not include FIFO_STATUS errors! */ |
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if (!int_status && !TW686X_FIFO_ERROR(fifo_status)) |
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return IRQ_NONE; |
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if (int_status & INT_STATUS_DMA_TOUT) { |
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dev_dbg(&dev->pci_dev->dev, |
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"DMA timeout. Resetting DMA for all channels\n"); |
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reset_ch = ~0; |
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goto reset_channels; |
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} |
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spin_lock_irqsave(&dev->lock, flags); |
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dma_en = reg_read(dev, DMA_CHANNEL_ENABLE); |
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spin_unlock_irqrestore(&dev->lock, flags); |
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video_en = dma_en & 0xff; |
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fifo_signal = ~(fifo_status & 0xff) & video_en; |
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fifo_ov = fifo_status >> 24; |
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fifo_bad = fifo_status >> 16; |
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/* Mask of channels with signal and FIFO errors */ |
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fifo_errors = fifo_signal & (fifo_ov | fifo_bad); |
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reset_ch = 0; |
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pb_status = reg_read(dev, PB_STATUS); |
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/* Coalesce video frame/error events */ |
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video_requests = (int_status & video_en) | fifo_errors; |
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audio_requests = (int_status & dma_en) >> 8; |
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if (video_requests) |
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tw686x_video_irq(dev, video_requests, pb_status, |
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fifo_status, &reset_ch); |
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if (audio_requests) |
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tw686x_audio_irq(dev, audio_requests, pb_status); |
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reset_channels: |
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if (reset_ch) { |
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spin_lock_irqsave(&dev->lock, flags); |
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tw686x_reset_channels(dev, reset_ch); |
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spin_unlock_irqrestore(&dev->lock, flags); |
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mod_timer(&dev->dma_delay_timer, |
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jiffies + msecs_to_jiffies(100)); |
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} |
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return IRQ_HANDLED; |
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} |
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static void tw686x_dev_release(struct v4l2_device *v4l2_dev) |
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{ |
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struct tw686x_dev *dev = container_of(v4l2_dev, struct tw686x_dev, |
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v4l2_dev); |
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unsigned int ch; |
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for (ch = 0; ch < max_channels(dev); ch++) |
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v4l2_ctrl_handler_free(&dev->video_channels[ch].ctrl_handler); |
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v4l2_device_unregister(&dev->v4l2_dev); |
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kfree(dev->audio_channels); |
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kfree(dev->video_channels); |
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kfree(dev); |
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} |
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static int tw686x_probe(struct pci_dev *pci_dev, |
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const struct pci_device_id *pci_id) |
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{ |
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struct tw686x_dev *dev; |
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int err; |
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dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
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if (!dev) |
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return -ENOMEM; |
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dev->type = pci_id->driver_data; |
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dev->dma_mode = dma_mode; |
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sprintf(dev->name, "tw%04X", pci_dev->device); |
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dev->video_channels = kcalloc(max_channels(dev), |
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sizeof(*dev->video_channels), GFP_KERNEL); |
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if (!dev->video_channels) { |
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err = -ENOMEM; |
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goto free_dev; |
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} |
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dev->audio_channels = kcalloc(max_channels(dev), |
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sizeof(*dev->audio_channels), GFP_KERNEL); |
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if (!dev->audio_channels) { |
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err = -ENOMEM; |
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goto free_video; |
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} |
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pr_info("%s: PCI %s, IRQ %d, MMIO 0x%lx (%s mode)\n", dev->name, |
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pci_name(pci_dev), pci_dev->irq, |
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(unsigned long)pci_resource_start(pci_dev, 0), |
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dma_mode_name(dma_mode)); |
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dev->pci_dev = pci_dev; |
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if (pci_enable_device(pci_dev)) { |
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err = -EIO; |
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goto free_audio; |
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} |
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pci_set_master(pci_dev); |
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err = pci_set_dma_mask(pci_dev, DMA_BIT_MASK(32)); |
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if (err) { |
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dev_err(&pci_dev->dev, "32-bit PCI DMA not supported\n"); |
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err = -EIO; |
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goto disable_pci; |
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} |
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err = pci_request_regions(pci_dev, dev->name); |
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if (err) { |
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dev_err(&pci_dev->dev, "unable to request PCI region\n"); |
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goto disable_pci; |
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} |
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dev->mmio = pci_ioremap_bar(pci_dev, 0); |
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if (!dev->mmio) { |
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dev_err(&pci_dev->dev, "unable to remap PCI region\n"); |
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err = -ENOMEM; |
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goto free_region; |
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} |
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/* Reset all subsystems */ |
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reg_write(dev, SYS_SOFT_RST, 0x0f); |
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mdelay(1); |
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reg_write(dev, SRST[0], 0x3f); |
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if (max_channels(dev) > 4) |
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reg_write(dev, SRST[1], 0x3f); |
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/* Disable the DMA engine */ |
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reg_write(dev, DMA_CMD, 0); |
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reg_write(dev, DMA_CHANNEL_ENABLE, 0); |
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/* Enable DMA FIFO overflow and pointer check */ |
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reg_write(dev, DMA_CONFIG, 0xffffff04); |
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reg_write(dev, DMA_CHANNEL_TIMEOUT, 0x140c8584); |
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reg_write(dev, DMA_TIMER_INTERVAL, dma_interval); |
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spin_lock_init(&dev->lock); |
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err = request_irq(pci_dev->irq, tw686x_irq, IRQF_SHARED, |
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dev->name, dev); |
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if (err < 0) { |
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dev_err(&pci_dev->dev, "unable to request interrupt\n"); |
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goto iounmap; |
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} |
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timer_setup(&dev->dma_delay_timer, tw686x_dma_delay, 0); |
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/* |
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* This must be set right before initializing v4l2_dev. |
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* It's used to release resources after the last handle |
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* held is released. |
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*/ |
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dev->v4l2_dev.release = tw686x_dev_release; |
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err = tw686x_video_init(dev); |
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if (err) { |
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dev_err(&pci_dev->dev, "can't register video\n"); |
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goto free_irq; |
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} |
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err = tw686x_audio_init(dev); |
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if (err) |
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dev_warn(&pci_dev->dev, "can't register audio\n"); |
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pci_set_drvdata(pci_dev, dev); |
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return 0; |
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free_irq: |
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free_irq(pci_dev->irq, dev); |
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iounmap: |
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pci_iounmap(pci_dev, dev->mmio); |
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free_region: |
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pci_release_regions(pci_dev); |
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disable_pci: |
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pci_disable_device(pci_dev); |
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free_audio: |
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kfree(dev->audio_channels); |
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free_video: |
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kfree(dev->video_channels); |
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free_dev: |
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kfree(dev); |
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return err; |
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} |
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static void tw686x_remove(struct pci_dev *pci_dev) |
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{ |
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struct tw686x_dev *dev = pci_get_drvdata(pci_dev); |
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unsigned long flags; |
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/* This guarantees the IRQ handler is no longer running, |
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* which means we can kiss good-bye some resources. |
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*/ |
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free_irq(pci_dev->irq, dev); |
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tw686x_video_free(dev); |
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tw686x_audio_free(dev); |
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del_timer_sync(&dev->dma_delay_timer); |
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pci_iounmap(pci_dev, dev->mmio); |
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pci_release_regions(pci_dev); |
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pci_disable_device(pci_dev); |
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/* |
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* Setting pci_dev to NULL allows to detect hardware is no longer |
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* available and will be used by vb2_ops. This is required because |
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* the device sometimes hot-unplugs itself as the result of a PCIe |
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* link down. |
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* The lock is really important here. |
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*/ |
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spin_lock_irqsave(&dev->lock, flags); |
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dev->pci_dev = NULL; |
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spin_unlock_irqrestore(&dev->lock, flags); |
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/* |
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* This calls tw686x_dev_release if it's the last reference. |
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* Otherwise, release is postponed until there are no users left. |
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*/ |
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v4l2_device_put(&dev->v4l2_dev); |
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} |
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/* |
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* On TW6864 and TW6868, all channels share the pair of video DMA SG tables, |
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* with 10-bit start_idx and end_idx determining start and end of frame buffer |
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* for particular channel. |
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* TW6868 with all its 8 channels would be problematic (only 127 SG entries per |
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* channel) but we support only 4 channels on this chip anyway (the first |
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* 4 channels are driven with internal video decoder, the other 4 would require |
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* an external TW286x part). |
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* |
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* On TW6865 and TW6869, each channel has its own DMA SG table, with indexes |
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* starting with 0. Both chips have complete sets of internal video decoders |
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* (respectively 4 or 8-channel). |
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* |
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* All chips have separate SG tables for two video frames. |
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*/ |
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/* driver_data is number of A/V channels */ |
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static const struct pci_device_id tw686x_pci_tbl[] = { |
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{ |
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PCI_DEVICE(PCI_VENDOR_ID_TECHWELL, 0x6864), |
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.driver_data = 4 |
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}, |
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{ |
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PCI_DEVICE(PCI_VENDOR_ID_TECHWELL, 0x6865), /* not tested */ |
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.driver_data = 4 | TYPE_SECOND_GEN |
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}, |
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/* |
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* TW6868 supports 8 A/V channels with an external TW2865 chip; |
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* not supported by the driver. |
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*/ |
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{ |
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PCI_DEVICE(PCI_VENDOR_ID_TECHWELL, 0x6868), /* not tested */ |
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.driver_data = 4 |
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}, |
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{ |
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PCI_DEVICE(PCI_VENDOR_ID_TECHWELL, 0x6869), |
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.driver_data = 8 | TYPE_SECOND_GEN}, |
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{} |
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}; |
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MODULE_DEVICE_TABLE(pci, tw686x_pci_tbl); |
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static struct pci_driver tw686x_pci_driver = { |
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.name = "tw686x", |
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.id_table = tw686x_pci_tbl, |
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.probe = tw686x_probe, |
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.remove = tw686x_remove, |
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}; |
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module_pci_driver(tw686x_pci_driver); |
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MODULE_DESCRIPTION("Driver for video frame grabber cards based on Intersil/Techwell TW686[4589]"); |
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MODULE_AUTHOR("Ezequiel Garcia <[email protected]>"); |
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MODULE_AUTHOR("Krzysztof Ha?asa <[email protected]>"); |
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MODULE_LICENSE("GPL v2");
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