linux/drivers/media/pci/mantis/mantis_uart.c
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   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 "dmxdev.h"
  31#include "dvbdev.h"
  32#include "dvb_demux.h"
  33#include "dvb_frontend.h"
  34#include "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
  41struct mantis_uart_params {
  42        enum mantis_baud        baud_rate;
  43        enum mantis_parity      parity;
  44};
  45
  46static struct {
  47        char string[7];
  48} rates[5] = {
  49        { "9600" },
  50        { "19200" },
  51        { "38400" },
  52        { "57600" },
  53        { "115200" }
  54};
  55
  56static struct {
  57        char string[5];
  58} parity[3] = {
  59        { "NONE" },
  60        { "ODD" },
  61        { "EVEN" }
  62};
  63
  64static 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
  91static 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
  96        stat = mmread(MANTIS_UART_STAT);
  97
  98        if (stat & MANTIS_UART_RXFIFO_FULL)
  99                dprintk(MANTIS_ERROR, 1, "RX Fifo FULL");
 100
 101        /*
 102         * MANTIS_UART_RXFIFO_DATA is only set if at least
 103         * config->bytes + 1 bytes are in the FIFO.
 104         */
 105        while (stat & MANTIS_UART_RXFIFO_DATA) {
 106                mantis_uart_read(mantis);
 107                stat = mmread(MANTIS_UART_STAT);
 108        }
 109
 110        /* re-enable UART (RX) interrupt */
 111        mantis_unmask_ints(mantis, MANTIS_INT_IRQ1);
 112}
 113
 114static int mantis_uart_setup(struct mantis_pci *mantis,
 115                             struct mantis_uart_params *params)
 116{
 117        u32 reg;
 118
 119        mmwrite((mmread(MANTIS_UART_CTL) | (params->parity & 0x3)), MANTIS_UART_CTL);
 120
 121        reg = mmread(MANTIS_UART_BAUD);
 122
 123        switch (params->baud_rate) {
 124        case MANTIS_BAUD_9600:
 125                reg |= 0xd8;
 126                break;
 127        case MANTIS_BAUD_19200:
 128                reg |= 0x6c;
 129                break;
 130        case MANTIS_BAUD_38400:
 131                reg |= 0x36;
 132                break;
 133        case MANTIS_BAUD_57600:
 134                reg |= 0x23;
 135                break;
 136        case MANTIS_BAUD_115200:
 137                reg |= 0x11;
 138                break;
 139        default:
 140                return -EINVAL;
 141        }
 142
 143        mmwrite(reg, MANTIS_UART_BAUD);
 144
 145        return 0;
 146}
 147
 148int mantis_uart_init(struct mantis_pci *mantis)
 149{
 150        struct mantis_hwconfig *config = mantis->hwconfig;
 151        struct mantis_uart_params params;
 152
 153        /* default parity: */
 154        params.baud_rate = config->baud_rate;
 155        params.parity = config->parity;
 156        dprintk(MANTIS_INFO, 1, "Initializing UART @ %sbps parity:%s",
 157                rates[params.baud_rate].string,
 158                parity[params.parity].string);
 159
 160        INIT_WORK(&mantis->uart_work, mantis_uart_work);
 161
 162        /* disable interrupt */
 163        mmwrite(mmread(MANTIS_UART_CTL) & 0xffef, MANTIS_UART_CTL);
 164
 165        mantis_uart_setup(mantis, &params);
 166
 167        /* default 1 byte */
 168        mmwrite((mmread(MANTIS_UART_BAUD) | (config->bytes << 8)), MANTIS_UART_BAUD);
 169
 170        /* flush buffer */
 171        mmwrite((mmread(MANTIS_UART_CTL) | MANTIS_UART_RXFLUSH), MANTIS_UART_CTL);
 172
 173        /* enable interrupt */
 174        mmwrite(mmread(MANTIS_UART_CTL) | MANTIS_UART_RXINT, MANTIS_UART_CTL);
 175        mantis_unmask_ints(mantis, MANTIS_INT_IRQ1);
 176
 177        schedule_work(&mantis->uart_work);
 178        dprintk(MANTIS_DEBUG, 1, "UART successfully initialized");
 179
 180        return 0;
 181}
 182EXPORT_SYMBOL_GPL(mantis_uart_init);
 183
 184void mantis_uart_exit(struct mantis_pci *mantis)
 185{
 186        /* disable interrupt */
 187        mantis_mask_ints(mantis, MANTIS_INT_IRQ1);
 188        mmwrite(mmread(MANTIS_UART_CTL) & 0xffef, MANTIS_UART_CTL);
 189        flush_work(&mantis->uart_work);
 190}
 191EXPORT_SYMBOL_GPL(mantis_uart_exit);
 192