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(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);
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(&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(&mantis->uart_work);
185}
186EXPORT_SYMBOL_GPL(mantis_uart_exit);
187