1/*
2 *  Driver for the Conexant CX23885 PCIe bridge
3 *
4 *  Copyright (c) 2007 Steven Toth <stoth@linuxtv.org>
5 *
6 *  This program is free software; you can redistribute it and/or modify
7 *  it under the terms of the GNU General Public License as published by
8 *  the Free Software Foundation; either version 2 of the License, or
9 *  (at your option) any later version.
10 *
11 *  This program is distributed in the hope that it will be useful,
12 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 *
15 *  GNU General Public License for more details.
16 */
17
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/moduleparam.h>
21#include <linux/init.h>
22
23#include "cx23885.h"
24
25static unsigned int vbibufs = 4;
26module_param(vbibufs, int, 0644);
27MODULE_PARM_DESC(vbibufs, "number of vbi buffers, range 2-32");
28
29static unsigned int vbi_debug;
30module_param(vbi_debug, int, 0644);
31MODULE_PARM_DESC(vbi_debug, "enable debug messages [vbi]");
32
33#define dprintk(level, fmt, arg...)\
34	do { if (vbi_debug >= level)\
35		printk(KERN_DEBUG "%s/0: " fmt, dev->name, ## arg);\
36	} while (0)
37
38/* ------------------------------------------------------------------ */
39
40#define VBI_LINE_LENGTH 1440
41#define VBI_NTSC_LINE_COUNT 12
42#define VBI_PAL_LINE_COUNT 18
43
44
45int cx23885_vbi_fmt(struct file *file, void *priv,
46	struct v4l2_format *f)
47{
48	struct cx23885_dev *dev = video_drvdata(file);
49
50	f->fmt.vbi.sampling_rate = 27000000;
51	f->fmt.vbi.samples_per_line = VBI_LINE_LENGTH;
52	f->fmt.vbi.sample_format = V4L2_PIX_FMT_GREY;
53	f->fmt.vbi.offset = 0;
54	f->fmt.vbi.flags = 0;
55	if (dev->tvnorm & V4L2_STD_525_60) {
56		/* ntsc */
57		f->fmt.vbi.start[0] = V4L2_VBI_ITU_525_F1_START + 9;
58		f->fmt.vbi.start[1] = V4L2_VBI_ITU_525_F2_START + 9;
59		f->fmt.vbi.count[0] = VBI_NTSC_LINE_COUNT;
60		f->fmt.vbi.count[1] = VBI_NTSC_LINE_COUNT;
61	} else if (dev->tvnorm & V4L2_STD_625_50) {
62		/* pal */
63		f->fmt.vbi.start[0] = V4L2_VBI_ITU_625_F1_START + 5;
64		f->fmt.vbi.start[1] = V4L2_VBI_ITU_625_F2_START + 5;
65		f->fmt.vbi.count[0] = VBI_PAL_LINE_COUNT;
66		f->fmt.vbi.count[1] = VBI_PAL_LINE_COUNT;
67	}
68
69	return 0;
70}
71
72/* We're given the Video Interrupt status register.
73 * The cx23885_video_irq() func has already validated
74 * the potential error bits, we just need to
75 * deal with vbi payload and return indication if
76 * we actually processed any payload.
77 */
78int cx23885_vbi_irq(struct cx23885_dev *dev, u32 status)
79{
80	u32 count;
81	int handled = 0;
82
83	if (status & VID_BC_MSK_VBI_RISCI1) {
84		dprintk(1, "%s() VID_BC_MSK_VBI_RISCI1\n", __func__);
85		spin_lock(&dev->slock);
86		count = cx_read(VID_A_GPCNT);
87		cx23885_video_wakeup(dev, &dev->vbiq, count);
88		spin_unlock(&dev->slock);
89		handled++;
90	}
91
92	return handled;
93}
94
95static int cx23885_start_vbi_dma(struct cx23885_dev    *dev,
96			 struct cx23885_dmaqueue *q,
97			 struct cx23885_buffer   *buf)
98{
99	dprintk(1, "%s()\n", __func__);
100
101	/* setup fifo + format */
102	cx23885_sram_channel_setup(dev, &dev->sram_channels[SRAM_CH02],
103				VBI_LINE_LENGTH, buf->risc.dma);
104
105	/* reset counter */
106	cx_write(VID_A_GPCNT_CTL, 3);
107	cx_write(VID_A_VBI_CTRL, 3);
108	cx_write(VBI_A_GPCNT_CTL, 3);
109	q->count = 0;
110
111	/* enable irq */
112	cx23885_irq_add_enable(dev, 0x01);
113	cx_set(VID_A_INT_MSK, 0x000022);
114
115	/* start dma */
116	cx_set(DEV_CNTRL2, (1<<5));
117	cx_set(VID_A_DMA_CTL, 0x22); /* FIFO and RISC enable */
118
119	return 0;
120}
121
122/* ------------------------------------------------------------------ */
123
124static int queue_setup(struct vb2_queue *q, const void *parg,
125			   unsigned int *num_buffers, unsigned int *num_planes,
126			   unsigned int sizes[], void *alloc_ctxs[])
127{
128	struct cx23885_dev *dev = q->drv_priv;
129	unsigned lines = VBI_PAL_LINE_COUNT;
130
131	if (dev->tvnorm & V4L2_STD_525_60)
132		lines = VBI_NTSC_LINE_COUNT;
133	*num_planes = 1;
134	sizes[0] = lines * VBI_LINE_LENGTH * 2;
135	alloc_ctxs[0] = dev->alloc_ctx;
136	return 0;
137}
138
139static int buffer_prepare(struct vb2_buffer *vb)
140{
141	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
142	struct cx23885_dev *dev = vb->vb2_queue->drv_priv;
143	struct cx23885_buffer *buf = container_of(vbuf,
144		struct cx23885_buffer, vb);
145	struct sg_table *sgt = vb2_dma_sg_plane_desc(vb, 0);
146	unsigned lines = VBI_PAL_LINE_COUNT;
147
148	if (dev->tvnorm & V4L2_STD_525_60)
149		lines = VBI_NTSC_LINE_COUNT;
150
151	if (vb2_plane_size(vb, 0) < lines * VBI_LINE_LENGTH * 2)
152		return -EINVAL;
153	vb2_set_plane_payload(vb, 0, lines * VBI_LINE_LENGTH * 2);
154
155	cx23885_risc_vbibuffer(dev->pci, &buf->risc,
156			 sgt->sgl,
157			 0, VBI_LINE_LENGTH * lines,
158			 VBI_LINE_LENGTH, 0,
159			 lines);
160	return 0;
161}
162
163static void buffer_finish(struct vb2_buffer *vb)
164{
165	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
166	struct cx23885_buffer *buf = container_of(vbuf,
167		struct cx23885_buffer, vb);
168
169	cx23885_free_buffer(vb->vb2_queue->drv_priv, buf);
170}
171
172/*
173 * The risc program for each buffer works as follows: it starts with a simple
174 * 'JUMP to addr + 12', which is effectively a NOP. Then the code to DMA the
175 * buffer follows and at the end we have a JUMP back to the start + 12 (skipping
176 * the initial JUMP).
177 *
178 * This is the risc program of the first buffer to be queued if the active list
179 * is empty and it just keeps DMAing this buffer without generating any
180 * interrupts.
181 *
182 * If a new buffer is added then the initial JUMP in the code for that buffer
183 * will generate an interrupt which signals that the previous buffer has been
184 * DMAed successfully and that it can be returned to userspace.
185 *
186 * It also sets the final jump of the previous buffer to the start of the new
187 * buffer, thus chaining the new buffer into the DMA chain. This is a single
188 * atomic u32 write, so there is no race condition.
189 *
190 * The end-result of all this that you only get an interrupt when a buffer
191 * is ready, so the control flow is very easy.
192 */
193static void buffer_queue(struct vb2_buffer *vb)
194{
195	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
196	struct cx23885_dev *dev = vb->vb2_queue->drv_priv;
197	struct cx23885_buffer *buf = container_of(vbuf,
198			struct cx23885_buffer, vb);
199	struct cx23885_buffer *prev;
200	struct cx23885_dmaqueue *q = &dev->vbiq;
201	unsigned long flags;
202
203	buf->risc.cpu[1] = cpu_to_le32(buf->risc.dma + 12);
204	buf->risc.jmp[0] = cpu_to_le32(RISC_JUMP | RISC_CNT_INC);
205	buf->risc.jmp[1] = cpu_to_le32(buf->risc.dma + 12);
206	buf->risc.jmp[2] = cpu_to_le32(0); /* bits 63-32 */
207
208	if (list_empty(&q->active)) {
209		spin_lock_irqsave(&dev->slock, flags);
210		list_add_tail(&buf->queue, &q->active);
211		spin_unlock_irqrestore(&dev->slock, flags);
212		dprintk(2, "[%p/%d] vbi_queue - first active\n",
213			buf, buf->vb.vb2_buf.index);
214
215	} else {
216		buf->risc.cpu[0] |= cpu_to_le32(RISC_IRQ1);
217		prev = list_entry(q->active.prev, struct cx23885_buffer,
218			queue);
219		spin_lock_irqsave(&dev->slock, flags);
220		list_add_tail(&buf->queue, &q->active);
221		spin_unlock_irqrestore(&dev->slock, flags);
222		prev->risc.jmp[1] = cpu_to_le32(buf->risc.dma);
223		dprintk(2, "[%p/%d] buffer_queue - append to active\n",
224			buf, buf->vb.vb2_buf.index);
225	}
226}
227
228static int cx23885_start_streaming(struct vb2_queue *q, unsigned int count)
229{
230	struct cx23885_dev *dev = q->drv_priv;
231	struct cx23885_dmaqueue *dmaq = &dev->vbiq;
232	struct cx23885_buffer *buf = list_entry(dmaq->active.next,
233			struct cx23885_buffer, queue);
234
235	cx23885_start_vbi_dma(dev, dmaq, buf);
236	return 0;
237}
238
239static void cx23885_stop_streaming(struct vb2_queue *q)
240{
241	struct cx23885_dev *dev = q->drv_priv;
242	struct cx23885_dmaqueue *dmaq = &dev->vbiq;
243	unsigned long flags;
244
245	cx_clear(VID_A_DMA_CTL, 0x22); /* FIFO and RISC enable */
246	spin_lock_irqsave(&dev->slock, flags);
247	while (!list_empty(&dmaq->active)) {
248		struct cx23885_buffer *buf = list_entry(dmaq->active.next,
249			struct cx23885_buffer, queue);
250
251		list_del(&buf->queue);
252		vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
253	}
254	spin_unlock_irqrestore(&dev->slock, flags);
255}
256
257
258struct vb2_ops cx23885_vbi_qops = {
259	.queue_setup    = queue_setup,
260	.buf_prepare  = buffer_prepare,
261	.buf_finish = buffer_finish,
262	.buf_queue    = buffer_queue,
263	.wait_prepare = vb2_ops_wait_prepare,
264	.wait_finish = vb2_ops_wait_finish,
265	.start_streaming = cx23885_start_streaming,
266	.stop_streaming = cx23885_stop_streaming,
267};
268