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 <linux/spinlock.h>
11#include <asm/io.h>
12
13#include <linux/signal.h>
14#include <linux/sched.h>
15#include <linux/interrupt.h>
16#include <linux/pci.h>
17
18#include <media/dmxdev.h>
19#include <media/dvbdev.h>
20#include <media/dvb_demux.h>
21#include <media/dvb_frontend.h>
22#include <media/dvb_net.h>
23
24#include "mantis_common.h"
25#include "mantis_reg.h"
26#include "mantis_uart.h"
27#include "mantis_input.h"
28
29struct mantis_uart_params {
30 enum mantis_baud baud_rate;
31 enum mantis_parity parity;
32};
33
34static struct {
35 char string[7];
36} rates[5] = {
37 { "9600" },
38 { "19200" },
39 { "38400" },
40 { "57600" },
41 { "115200" }
42};
43
44static struct {
45 char string[5];
46} parity[3] = {
47 { "NONE" },
48 { "ODD" },
49 { "EVEN" }
50};
51
52static void mantis_uart_read(struct mantis_pci *mantis)
53{
54 struct mantis_hwconfig *config = mantis->hwconfig;
55 int i, scancode = 0, err = 0;
56
57 /* get data */
58 dprintk(MANTIS_DEBUG, 1, "UART Reading ...");
59 for (i = 0; i < (config->bytes + 1); i++) {
60 int data = mmread(MANTIS_UART_RXD);
61
62 dprintk(MANTIS_DEBUG, 0, " <%02x>", data);
63
64 scancode = (scancode << 8) | (data & 0x3f);
65 err |= data;
66
67 if (data & (1 << 7))
68 dprintk(MANTIS_ERROR, 1, "UART framing error");
69
70 if (data & (1 << 6))
71 dprintk(MANTIS_ERROR, 1, "UART parity error");
72 }
73 dprintk(MANTIS_DEBUG, 0, "\n");
74
75 if ((err & 0xC0) == 0)
76 mantis_input_process(mantis, scancode);
77}
78
79static void mantis_uart_work(struct work_struct *work)
80{
81 struct mantis_pci *mantis = container_of(work, struct mantis_pci, uart_work);
82 u32 stat;
83 unsigned long timeout;
84
85 stat = mmread(MANTIS_UART_STAT);
86
87 if (stat & MANTIS_UART_RXFIFO_FULL)
88 dprintk(MANTIS_ERROR, 1, "RX Fifo FULL");
89
90 /*
91 * MANTIS_UART_RXFIFO_DATA is only set if at least
92 * config->bytes + 1 bytes are in the FIFO.
93 */
94
95 /* FIXME: is 10ms good enough ? */
96 timeout = jiffies + msecs_to_jiffies(m: 10);
97 while (stat & MANTIS_UART_RXFIFO_DATA) {
98 mantis_uart_read(mantis);
99 stat = mmread(MANTIS_UART_STAT);
100
101 if (!time_is_after_jiffies(timeout))
102 break;
103 }
104
105 /* re-enable UART (RX) interrupt */
106 mantis_unmask_ints(mantis, MANTIS_INT_IRQ1);
107}
108
109static int mantis_uart_setup(struct mantis_pci *mantis,
110 struct mantis_uart_params *params)
111{
112 u32 reg;
113
114 mmwrite((mmread(MANTIS_UART_CTL) | (params->parity & 0x3)), MANTIS_UART_CTL);
115
116 reg = mmread(MANTIS_UART_BAUD);
117
118 switch (params->baud_rate) {
119 case MANTIS_BAUD_9600:
120 reg |= 0xd8;
121 break;
122 case MANTIS_BAUD_19200:
123 reg |= 0x6c;
124 break;
125 case MANTIS_BAUD_38400:
126 reg |= 0x36;
127 break;
128 case MANTIS_BAUD_57600:
129 reg |= 0x23;
130 break;
131 case MANTIS_BAUD_115200:
132 reg |= 0x11;
133 break;
134 default:
135 return -EINVAL;
136 }
137
138 mmwrite(reg, MANTIS_UART_BAUD);
139
140 return 0;
141}
142
143int mantis_uart_init(struct mantis_pci *mantis)
144{
145 struct mantis_hwconfig *config = mantis->hwconfig;
146 struct mantis_uart_params params;
147
148 /* default parity: */
149 params.baud_rate = config->baud_rate;
150 params.parity = config->parity;
151 dprintk(MANTIS_INFO, 1, "Initializing UART @ %sbps parity:%s",
152 rates[params.baud_rate].string,
153 parity[params.parity].string);
154
155 INIT_WORK(&mantis->uart_work, mantis_uart_work);
156
157 /* disable interrupt */
158 mmwrite(mmread(MANTIS_UART_CTL) & 0xffef, MANTIS_UART_CTL);
159
160 mantis_uart_setup(mantis, params: &params);
161
162 /* default 1 byte */
163 mmwrite((mmread(MANTIS_UART_BAUD) | (config->bytes << 8)), MANTIS_UART_BAUD);
164
165 /* flush buffer */
166 mmwrite((mmread(MANTIS_UART_CTL) | MANTIS_UART_RXFLUSH), MANTIS_UART_CTL);
167
168 /* enable interrupt */
169 mmwrite(mmread(MANTIS_UART_CTL) | MANTIS_UART_RXINT, MANTIS_UART_CTL);
170 mantis_unmask_ints(mantis, MANTIS_INT_IRQ1);
171
172 schedule_work(work: &mantis->uart_work);
173 dprintk(MANTIS_DEBUG, 1, "UART successfully initialized");
174
175 return 0;
176}
177EXPORT_SYMBOL_GPL(mantis_uart_init);
178
179void mantis_uart_exit(struct mantis_pci *mantis)
180{
181 /* disable interrupt */
182 mantis_mask_ints(mantis, MANTIS_INT_IRQ1);
183 mmwrite(mmread(MANTIS_UART_CTL) & 0xffef, MANTIS_UART_CTL);
184 flush_work(work: &mantis->uart_work);
185}
186EXPORT_SYMBOL_GPL(mantis_uart_exit);
187

source code of linux/drivers/media/pci/mantis/mantis_uart.c