LXR linux/drivers/serial/s3c6400.c

   1/* linux/drivers/serial/s3c6400.c
   2 *
   3 * Driver for Samsung S3C6400 and S3C6410 SoC onboard UARTs.
   4 *
   5 * Copyright 2008 Openmoko,  Inc.
   6 * Copyright 2008 Simtec Electronics
   7 *      Ben Dooks <ben@simtec.co.uk>
   8 *      http://armlinux.simtec.co.uk/
   9 *
  10 * This program is free software; you can redistribute it and/or modify
  11 * it under the terms of the GNU General Public License version 2 as
  12 * published by the Free Software Foundation.
  13*/
  14
  15#include <linux/module.h>
  16#include <linux/ioport.h>
  17#include <linux/io.h>
  18#include <linux/platform_device.h>
  19#include <linux/init.h>
  20#include <linux/serial_core.h>
  21#include <linux/serial.h>
  22
  23#include <asm/irq.h>
  24#include <mach/hardware.h>
  25
  26#include <plat/regs-serial.h>
  27
  28#include "samsung.h"
  29
  30static int s3c6400_serial_setsource(struct uart_port *port,
  31                                    struct s3c24xx_uart_clksrc *clk)
  32{
  33        unsigned long ucon = rd_regl(port, S3C2410_UCON);
  34
  35        if (strcmp(clk->name, "uclk0") == 0) {
  36                ucon &= ~S3C6400_UCON_CLKMASK;
  37                ucon |= S3C6400_UCON_UCLK0;
  38        } else if (strcmp(clk->name, "uclk1") == 0)
  39                ucon |= S3C6400_UCON_UCLK1;
  40        else if (strcmp(clk->name, "pclk") == 0) {
  41                /* See notes about transitioning from UCLK to PCLK */
  42                ucon &= ~S3C6400_UCON_UCLK0;
  43        } else {
  44                printk(KERN_ERR "unknown clock source %s\n", clk->name);
  45                return -EINVAL;
  46        }
  47
  48        wr_regl(port, S3C2410_UCON, ucon);
  49        return 0;
  50}
  51
  52
  53static int s3c6400_serial_getsource(struct uart_port *port,
  54                                    struct s3c24xx_uart_clksrc *clk)
  55{
  56        u32 ucon = rd_regl(port, S3C2410_UCON);
  57
  58        clk->divisor = 1;
  59
  60        switch (ucon & S3C6400_UCON_CLKMASK) {
  61        case S3C6400_UCON_UCLK0:
  62                clk->name = "uclk0";
  63                break;
  64
  65        case S3C6400_UCON_UCLK1:
  66                clk->name = "uclk1";
  67                break;
  68
  69        case S3C6400_UCON_PCLK:
  70        case S3C6400_UCON_PCLK2:
  71                clk->name = "pclk";
  72                break;
  73        }
  74
  75        return 0;
  76}
  77
  78static int s3c6400_serial_resetport(struct uart_port *port,
  79                                    struct s3c2410_uartcfg *cfg)
  80{
  81        unsigned long ucon = rd_regl(port, S3C2410_UCON);
  82
  83        dbg("s3c6400_serial_resetport: port=%p (%08lx), cfg=%p\n",
  84            port, port->mapbase, cfg);
  85
  86        /* ensure we don't change the clock settings... */
  87
  88        ucon &= S3C6400_UCON_CLKMASK;
  89
  90        wr_regl(port, S3C2410_UCON,  ucon | cfg->ucon);
  91        wr_regl(port, S3C2410_ULCON, cfg->ulcon);
  92
  93        /* reset both fifos */
  94
  95        wr_regl(port, S3C2410_UFCON, cfg->ufcon | S3C2410_UFCON_RESETBOTH);
  96        wr_regl(port, S3C2410_UFCON, cfg->ufcon);
  97
  98        return 0;
  99}
 100
 101static struct s3c24xx_uart_info s3c6400_uart_inf = {
 102        .name           = "Samsung S3C6400 UART",
 103        .type           = PORT_S3C6400,
 104        .fifosize       = 64,
 105        .has_divslot    = 1,
 106        .rx_fifomask    = S3C2440_UFSTAT_RXMASK,
 107        .rx_fifoshift   = S3C2440_UFSTAT_RXSHIFT,
 108        .rx_fifofull    = S3C2440_UFSTAT_RXFULL,
 109        .tx_fifofull    = S3C2440_UFSTAT_TXFULL,
 110        .tx_fifomask    = S3C2440_UFSTAT_TXMASK,
 111        .tx_fifoshift   = S3C2440_UFSTAT_TXSHIFT,
 112        .get_clksrc     = s3c6400_serial_getsource,
 113        .set_clksrc     = s3c6400_serial_setsource,
 114        .reset_port     = s3c6400_serial_resetport,
 115};
 116
 117/* device management */
 118
 119static int s3c6400_serial_probe(struct platform_device *dev)
 120{
 121        dbg("s3c6400_serial_probe: dev=%p\n", dev);
 122        return s3c24xx_serial_probe(dev, &s3c6400_uart_inf);
 123}
 124
 125static struct platform_driver s3c6400_serial_drv = {
 126        .probe          = s3c6400_serial_probe,
 127        .remove         = s3c24xx_serial_remove,
 128        .driver         = {
 129                .name   = "s3c6400-uart",
 130                .owner  = THIS_MODULE,
 131        },
 132};
 133
 134s3c24xx_console_init(&s3c6400_serial_drv, &s3c6400_uart_inf);
 135
 136static int __init s3c6400_serial_init(void)
 137{
 138        return s3c24xx_serial_init(&s3c6400_serial_drv, &s3c6400_uart_inf);
 139}
 140
 141static void __exit s3c6400_serial_exit(void)
 142{
 143        platform_driver_unregister(&s3c6400_serial_drv);
 144}
 145
 146module_init(s3c6400_serial_init);
 147module_exit(s3c6400_serial_exit);
 148
 149MODULE_DESCRIPTION("Samsung S3C6400,S3C6410 SoC Serial port driver");
 150MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 151MODULE_LICENSE("GPL v2");
 152MODULE_ALIAS("platform:s3c6400-uart");
 153