1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 	Mantis PCI bridge driver
4 
5 	Copyright (C) Manu Abraham (abraham.manu@gmail.com)
6 
7 */
8 
9 #include <linux/kernel.h>
10 #include <asm/page.h>
11 #include <linux/vmalloc.h>
12 #include <linux/pci.h>
13 
14 #include <asm/irq.h>
15 #include <linux/signal.h>
16 #include <linux/sched.h>
17 #include <linux/interrupt.h>
18 
19 #include <media/dmxdev.h>
20 #include <media/dvbdev.h>
21 #include <media/dvb_demux.h>
22 #include <media/dvb_frontend.h>
23 #include <media/dvb_net.h>
24 
25 #include "mantis_common.h"
26 #include "mantis_reg.h"
27 #include "mantis_dma.h"
28 
29 #define RISC_WRITE		(0x01 << 28)
30 #define RISC_JUMP		(0x07 << 28)
31 #define RISC_IRQ		(0x01 << 24)
32 
33 #define RISC_STATUS(status)	((((~status) & 0x0f) << 20) | ((status & 0x0f) << 16))
34 #define RISC_FLUSH(risc_pos)		(risc_pos = 0)
35 #define RISC_INSTR(risc_pos, opcode)	(mantis->risc_cpu[risc_pos++] = cpu_to_le32(opcode))
36 
37 #define MANTIS_BUF_SIZE		(64 * 1024)
38 #define MANTIS_BLOCK_BYTES      (MANTIS_BUF_SIZE / 4)
39 #define MANTIS_DMA_TR_BYTES     (2 * 1024) /* upper limit: 4095 bytes. */
40 #define MANTIS_BLOCK_COUNT	(MANTIS_BUF_SIZE / MANTIS_BLOCK_BYTES)
41 
42 #define MANTIS_DMA_TR_UNITS     (MANTIS_BLOCK_BYTES / MANTIS_DMA_TR_BYTES)
43 /* MANTIS_BUF_SIZE / MANTIS_DMA_TR_UNITS must not exceed MANTIS_RISC_SIZE (4k RISC cmd buffer) */
44 #define MANTIS_RISC_SIZE	PAGE_SIZE /* RISC program must fit here. */
45 
46 int mantis_dma_exit(struct mantis_pci *mantis)
47 {
48 	if (mantis->buf_cpu) {
49 		dprintk(MANTIS_ERROR, 1,
50 			"DMA=0x%lx cpu=0x%p size=%d",
51 			(unsigned long) mantis->buf_dma,
52 			 mantis->buf_cpu,
53 			 MANTIS_BUF_SIZE);
54 
55 		dma_free_coherent(&mantis->pdev->dev, MANTIS_BUF_SIZE,
56 				  mantis->buf_cpu, mantis->buf_dma);
57 
58 		mantis->buf_cpu = NULL;
59 	}
60 	if (mantis->risc_cpu) {
61 		dprintk(MANTIS_ERROR, 1,
62 			"RISC=0x%lx cpu=0x%p size=%lx",
63 			(unsigned long) mantis->risc_dma,
64 			mantis->risc_cpu,
65 			MANTIS_RISC_SIZE);
66 
67 		dma_free_coherent(&mantis->pdev->dev, MANTIS_RISC_SIZE,
68 				  mantis->risc_cpu, mantis->risc_dma);
69 
70 		mantis->risc_cpu = NULL;
71 	}
72 
73 	return 0;
74 }
75 EXPORT_SYMBOL_GPL(mantis_dma_exit);
76 
77 static inline int mantis_alloc_buffers(struct mantis_pci *mantis)
78 {
79 	if (!mantis->buf_cpu) {
80 		mantis->buf_cpu = dma_alloc_coherent(&mantis->pdev->dev,
81 						     MANTIS_BUF_SIZE,
82 						     &mantis->buf_dma, GFP_KERNEL);
83 		if (!mantis->buf_cpu) {
84 			dprintk(MANTIS_ERROR, 1,
85 				"DMA buffer allocation failed");
86 
87 			goto err;
88 		}
89 		dprintk(MANTIS_ERROR, 1,
90 			"DMA=0x%lx cpu=0x%p size=%d",
91 			(unsigned long) mantis->buf_dma,
92 			mantis->buf_cpu, MANTIS_BUF_SIZE);
93 	}
94 	if (!mantis->risc_cpu) {
95 		mantis->risc_cpu = dma_alloc_coherent(&mantis->pdev->dev,
96 						      MANTIS_RISC_SIZE,
97 						      &mantis->risc_dma, GFP_KERNEL);
98 
99 		if (!mantis->risc_cpu) {
100 			dprintk(MANTIS_ERROR, 1,
101 				"RISC program allocation failed");
102 
103 			mantis_dma_exit(mantis);
104 
105 			goto err;
106 		}
107 		dprintk(MANTIS_ERROR, 1,
108 			"RISC=0x%lx cpu=0x%p size=%lx",
109 			(unsigned long) mantis->risc_dma,
110 			mantis->risc_cpu, MANTIS_RISC_SIZE);
111 	}
112 
113 	return 0;
114 err:
115 	dprintk(MANTIS_ERROR, 1, "Out of memory (?) .....");
116 	return -ENOMEM;
117 }
118 
119 int mantis_dma_init(struct mantis_pci *mantis)
120 {
121 	int err;
122 
123 	dprintk(MANTIS_DEBUG, 1, "Mantis DMA init");
124 	err = mantis_alloc_buffers(mantis);
125 	if (err < 0) {
126 		dprintk(MANTIS_ERROR, 1, "Error allocating DMA buffer");
127 
128 		/* Stop RISC Engine */
129 		mmwrite(0, MANTIS_DMA_CTL);
130 
131 		return err;
132 	}
133 
134 	return 0;
135 }
136 EXPORT_SYMBOL_GPL(mantis_dma_init);
137 
138 static inline void mantis_risc_program(struct mantis_pci *mantis)
139 {
140 	u32 buf_pos = 0;
141 	u32 line, step;
142 	u32 risc_pos;
143 
144 	dprintk(MANTIS_DEBUG, 1, "Mantis create RISC program");
145 	RISC_FLUSH(risc_pos);
146 
147 	dprintk(MANTIS_DEBUG, 1, "risc len lines %u, bytes per line %u, bytes per DMA tr %u",
148 		MANTIS_BLOCK_COUNT, MANTIS_BLOCK_BYTES, MANTIS_DMA_TR_BYTES);
149 
150 	for (line = 0; line < MANTIS_BLOCK_COUNT; line++) {
151 		for (step = 0; step < MANTIS_DMA_TR_UNITS; step++) {
152 			dprintk(MANTIS_DEBUG, 1, "RISC PROG line=[%d], step=[%d]", line, step);
153 			if (step == 0) {
154 				RISC_INSTR(risc_pos, RISC_WRITE	|
155 					   RISC_IRQ	|
156 					   RISC_STATUS(line) |
157 					   MANTIS_DMA_TR_BYTES);
158 			} else {
159 				RISC_INSTR(risc_pos, RISC_WRITE | MANTIS_DMA_TR_BYTES);
160 			}
161 			RISC_INSTR(risc_pos, mantis->buf_dma + buf_pos);
162 			buf_pos += MANTIS_DMA_TR_BYTES;
163 		  }
164 	}
165 	RISC_INSTR(risc_pos, RISC_JUMP);
166 	RISC_INSTR(risc_pos, mantis->risc_dma);
167 }
168 
169 void mantis_dma_start(struct mantis_pci *mantis)
170 {
171 	dprintk(MANTIS_DEBUG, 1, "Mantis Start DMA engine");
172 
173 	mantis_risc_program(mantis);
174 	mmwrite(mantis->risc_dma, MANTIS_RISC_START);
175 	mmwrite(mmread(MANTIS_GPIF_ADDR) | MANTIS_GPIF_HIFRDWRN, MANTIS_GPIF_ADDR);
176 
177 	mmwrite(0, MANTIS_DMA_CTL);
178 	mantis->last_block = mantis->busy_block = 0;
179 
180 	mantis_unmask_ints(mantis, MANTIS_INT_RISCI);
181 
182 	mmwrite(MANTIS_FIFO_EN | MANTIS_DCAP_EN
183 			       | MANTIS_RISC_EN, MANTIS_DMA_CTL);
184 
185 }
186 
187 void mantis_dma_stop(struct mantis_pci *mantis)
188 {
189 	dprintk(MANTIS_DEBUG, 1, "Mantis Stop DMA engine");
190 
191 	mmwrite((mmread(MANTIS_GPIF_ADDR) & (~(MANTIS_GPIF_HIFRDWRN))), MANTIS_GPIF_ADDR);
192 
193 	mmwrite((mmread(MANTIS_DMA_CTL) & ~(MANTIS_FIFO_EN |
194 					    MANTIS_DCAP_EN |
195 					    MANTIS_RISC_EN)), MANTIS_DMA_CTL);
196 
197 	mmwrite(mmread(MANTIS_INT_STAT), MANTIS_INT_STAT);
198 
199 	mantis_mask_ints(mantis, MANTIS_INT_RISCI | MANTIS_INT_RISCEN);
200 }
201 
202 
203 void mantis_dma_xfer(struct tasklet_struct *t)
204 {
205 	struct mantis_pci *mantis = from_tasklet(mantis, t, tasklet);
206 	struct mantis_hwconfig *config = mantis->hwconfig;
207 
208 	while (mantis->last_block != mantis->busy_block) {
209 		dprintk(MANTIS_DEBUG, 1, "last block=[%d] finished block=[%d]",
210 			mantis->last_block, mantis->busy_block);
211 
212 		(config->ts_size ? dvb_dmx_swfilter_204 : dvb_dmx_swfilter)
213 		(&mantis->demux, &mantis->buf_cpu[mantis->last_block * MANTIS_BLOCK_BYTES], MANTIS_BLOCK_BYTES);
214 		mantis->last_block = (mantis->last_block + 1) % MANTIS_BLOCK_COUNT;
215 	}
216 }
217