drivers/media/pci/mantis/mantis_uart.c

   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
  29 #include "dmxdev.h"
  30 #include "dvbdev.h"
  31 #include "dvb_demux.h"
  32 #include "dvb_frontend.h"
  33 #include "dvb_net.h"
  34
  35 #include "mantis_common.h"
  36 #include "mantis_reg.h"
  37 #include "mantis_uart.h"
  38
  39 struct mantis_uart_params {
  40         enum mantis_baud        baud_rate;
  41         enum mantis_parity      parity;
  42 };
  43
  44 static struct {
  45         char string[7];
  46 } rates[5] = {
  47         { "9600" },
  48         { "19200" },
  49         { "38400" },
  50         { "57600" },
  51         { "115200" }
  52 };
  53
  54 static struct {
  55         char string[5];
  56 } parity[3] = {
  57         { "NONE" },
  58         { "ODD" },
  59         { "EVEN" }
  60 };
  61
  62 #define UART_MAX_BUF                    16
  63
  64 static int mantis_uart_read(struct mantis_pci *mantis, u8 *data)
  65 {
  66         struct mantis_hwconfig *config = mantis->hwconfig;
  67         u32 stat = 0, i;
  68
  69         /* get data */
  70         for (i = 0; i < (config->bytes + 1); i++) {
  71
  72                 stat = mmread(MANTIS_UART_STAT);
  73
  74                 if (stat & MANTIS_UART_RXFIFO_FULL) {
  75                         dprintk(MANTIS_ERROR, 1, "RX Fifo FULL");
  76                 }
  77                 data[i] = mmread(MANTIS_UART_RXD) & 0x3f;
  78
  79                 dprintk(MANTIS_DEBUG, 1, "Reading ... <%02x>", data[i] & 0x3f);
  80
  81                 if (data[i] & (1 << 7)) {
  82                         dprintk(MANTIS_ERROR, 1, "UART framing error");
  83                         return -EINVAL;
  84                 }
  85                 if (data[i] & (1 << 6)) {
  86                         dprintk(MANTIS_ERROR, 1, "UART parity error");
  87                         return -EINVAL;
  88                 }
  89         }
  90
  91         return 0;
  92 }
  93
  94 static void mantis_uart_work(struct work_struct *work)
  95 {
  96         struct mantis_pci *mantis = container_of(work, struct mantis_pci, uart_work);
  97         struct mantis_hwconfig *config = mantis->hwconfig;
  98         u8 buf[16];
  99         int i;
 100
 101         mantis_uart_read(mantis, buf);
 102
 103         for (i = 0; i < (config->bytes + 1); i++)
 104                 dprintk(MANTIS_INFO, 1, "UART BUF:%d <%02x> ", i, buf[i]);
 105
 106         dprintk(MANTIS_DEBUG, 0, "\n");
 107 }
 108
 109 static 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
 143 int 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_waitqueue_head(&mantis->uart_wq);
 156         spin_lock_init(&mantis->uart_lock);
 157
 158         INIT_WORK(&mantis->uart_work, mantis_uart_work);
 159
 160         /* disable interrupt */
 161         mmwrite(mmread(MANTIS_UART_CTL) & 0xffef, MANTIS_UART_CTL);
 162
 163         mantis_uart_setup(mantis, &params);
 164
 165         /* default 1 byte */
 166         mmwrite((mmread(MANTIS_UART_BAUD) | (config->bytes << 8)), MANTIS_UART_BAUD);
 167
 168         /* flush buffer */
 169         mmwrite((mmread(MANTIS_UART_CTL) | MANTIS_UART_RXFLUSH), MANTIS_UART_CTL);
 170
 171         /* enable interrupt */
 172         mmwrite(mmread(MANTIS_INT_MASK) | 0x800, MANTIS_INT_MASK);
 173         mmwrite(mmread(MANTIS_UART_CTL) | MANTIS_UART_RXINT, MANTIS_UART_CTL);
 174
 175         schedule_work(&mantis->uart_work);
 176         dprintk(MANTIS_DEBUG, 1, "UART successfully initialized");
 177
 178         return 0;
 179 }
 180 EXPORT_SYMBOL_GPL(mantis_uart_init);
 181
 182 void mantis_uart_exit(struct mantis_pci *mantis)
 183 {
 184         /* disable interrupt */
 185         mmwrite(mmread(MANTIS_UART_CTL) & 0xffef, MANTIS_UART_CTL);
 186         flush_work(&mantis->uart_work);
 187 }
 188 EXPORT_SYMBOL_GPL(mantis_uart_exit);