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 #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);