xref: /linux/drivers/media/pci/mantis/mantis_uart.c (revision e9f0878c4b2004ac19581274c1ae4c61ae3ca70e)
1 /*
2 	Mantis PCI bridge driver
3 
4 	Copyright (C) Manu Abraham (abraham.manu@gmail.com)
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 	GNU General Public License for more details.
15 
16 	You should have received a copy of the GNU General Public License
17 	along with this program; if not, write to the Free Software
18 	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20 
21 #include <linux/kernel.h>
22 #include <linux/spinlock.h>
23 #include <asm/io.h>
24 
25 #include <linux/signal.h>
26 #include <linux/sched.h>
27 #include <linux/interrupt.h>
28 #include <linux/pci.h>
29 
30 #include <media/dmxdev.h>
31 #include <media/dvbdev.h>
32 #include <media/dvb_demux.h>
33 #include <media/dvb_frontend.h>
34 #include <media/dvb_net.h>
35 
36 #include "mantis_common.h"
37 #include "mantis_reg.h"
38 #include "mantis_uart.h"
39 #include "mantis_input.h"
40 
41 struct mantis_uart_params {
42 	enum mantis_baud	baud_rate;
43 	enum mantis_parity	parity;
44 };
45 
46 static struct {
47 	char string[7];
48 } rates[5] = {
49 	{ "9600" },
50 	{ "19200" },
51 	{ "38400" },
52 	{ "57600" },
53 	{ "115200" }
54 };
55 
56 static struct {
57 	char string[5];
58 } parity[3] = {
59 	{ "NONE" },
60 	{ "ODD" },
61 	{ "EVEN" }
62 };
63 
64 static void mantis_uart_read(struct mantis_pci *mantis)
65 {
66 	struct mantis_hwconfig *config = mantis->hwconfig;
67 	int i, scancode = 0, err = 0;
68 
69 	/* get data */
70 	dprintk(MANTIS_DEBUG, 1, "UART Reading ...");
71 	for (i = 0; i < (config->bytes + 1); i++) {
72 		int data = mmread(MANTIS_UART_RXD);
73 
74 		dprintk(MANTIS_DEBUG, 0, " <%02x>", data);
75 
76 		scancode = (scancode << 8) | (data & 0x3f);
77 		err |= data;
78 
79 		if (data & (1 << 7))
80 			dprintk(MANTIS_ERROR, 1, "UART framing error");
81 
82 		if (data & (1 << 6))
83 			dprintk(MANTIS_ERROR, 1, "UART parity error");
84 	}
85 	dprintk(MANTIS_DEBUG, 0, "\n");
86 
87 	if ((err & 0xC0) == 0)
88 		mantis_input_process(mantis, scancode);
89 }
90 
91 static void mantis_uart_work(struct work_struct *work)
92 {
93 	struct mantis_pci *mantis = container_of(work, struct mantis_pci, uart_work);
94 	u32 stat;
95 	unsigned long timeout;
96 
97 	stat = mmread(MANTIS_UART_STAT);
98 
99 	if (stat & MANTIS_UART_RXFIFO_FULL)
100 		dprintk(MANTIS_ERROR, 1, "RX Fifo FULL");
101 
102 	/*
103 	 * MANTIS_UART_RXFIFO_DATA is only set if at least
104 	 * config->bytes + 1 bytes are in the FIFO.
105 	 */
106 
107 	/* FIXME: is 10ms good enough ? */
108 	timeout = jiffies +  msecs_to_jiffies(10);
109 	while (stat & MANTIS_UART_RXFIFO_DATA) {
110 		mantis_uart_read(mantis);
111 		stat = mmread(MANTIS_UART_STAT);
112 
113 		if (!time_is_after_jiffies(timeout))
114 			break;
115 	}
116 
117 	/* re-enable UART (RX) interrupt */
118 	mantis_unmask_ints(mantis, MANTIS_INT_IRQ1);
119 }
120 
121 static int mantis_uart_setup(struct mantis_pci *mantis,
122 			     struct mantis_uart_params *params)
123 {
124 	u32 reg;
125 
126 	mmwrite((mmread(MANTIS_UART_CTL) | (params->parity & 0x3)), MANTIS_UART_CTL);
127 
128 	reg = mmread(MANTIS_UART_BAUD);
129 
130 	switch (params->baud_rate) {
131 	case MANTIS_BAUD_9600:
132 		reg |= 0xd8;
133 		break;
134 	case MANTIS_BAUD_19200:
135 		reg |= 0x6c;
136 		break;
137 	case MANTIS_BAUD_38400:
138 		reg |= 0x36;
139 		break;
140 	case MANTIS_BAUD_57600:
141 		reg |= 0x23;
142 		break;
143 	case MANTIS_BAUD_115200:
144 		reg |= 0x11;
145 		break;
146 	default:
147 		return -EINVAL;
148 	}
149 
150 	mmwrite(reg, MANTIS_UART_BAUD);
151 
152 	return 0;
153 }
154 
155 int mantis_uart_init(struct mantis_pci *mantis)
156 {
157 	struct mantis_hwconfig *config = mantis->hwconfig;
158 	struct mantis_uart_params params;
159 
160 	/* default parity: */
161 	params.baud_rate = config->baud_rate;
162 	params.parity = config->parity;
163 	dprintk(MANTIS_INFO, 1, "Initializing UART @ %sbps parity:%s",
164 		rates[params.baud_rate].string,
165 		parity[params.parity].string);
166 
167 	INIT_WORK(&mantis->uart_work, mantis_uart_work);
168 
169 	/* disable interrupt */
170 	mmwrite(mmread(MANTIS_UART_CTL) & 0xffef, MANTIS_UART_CTL);
171 
172 	mantis_uart_setup(mantis, &params);
173 
174 	/* default 1 byte */
175 	mmwrite((mmread(MANTIS_UART_BAUD) | (config->bytes << 8)), MANTIS_UART_BAUD);
176 
177 	/* flush buffer */
178 	mmwrite((mmread(MANTIS_UART_CTL) | MANTIS_UART_RXFLUSH), MANTIS_UART_CTL);
179 
180 	/* enable interrupt */
181 	mmwrite(mmread(MANTIS_UART_CTL) | MANTIS_UART_RXINT, MANTIS_UART_CTL);
182 	mantis_unmask_ints(mantis, MANTIS_INT_IRQ1);
183 
184 	schedule_work(&mantis->uart_work);
185 	dprintk(MANTIS_DEBUG, 1, "UART successfully initialized");
186 
187 	return 0;
188 }
189 EXPORT_SYMBOL_GPL(mantis_uart_init);
190 
191 void mantis_uart_exit(struct mantis_pci *mantis)
192 {
193 	/* disable interrupt */
194 	mantis_mask_ints(mantis, MANTIS_INT_IRQ1);
195 	mmwrite(mmread(MANTIS_UART_CTL) & 0xffef, MANTIS_UART_CTL);
196 	flush_work(&mantis->uart_work);
197 }
198 EXPORT_SYMBOL_GPL(mantis_uart_exit);
199