LXR linux/drivers/serial/s3c2412.c

   1/* linux/drivers/serial/s3c2412.c
   2 *
   3 * Driver for Samsung S3C2412 and S3C2413 SoC onboard UARTs.
   4 *
   5 * Ben Dooks, Copyright (c) 2003-2005,2008 Simtec Electronics
   6 *      http://armlinux.simtec.co.uk/
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License version 2 as
  10 * published by the Free Software Foundation.
  11*/
  12
  13#include <linux/module.h>
  14#include <linux/ioport.h>
  15#include <linux/io.h>
  16#include <linux/platform_device.h>
  17#include <linux/init.h>
  18#include <linux/serial_core.h>
  19#include <linux/serial.h>
  20
  21#include <asm/irq.h>
  22#include <mach/hardware.h>
  23
  24#include <plat/regs-serial.h>
  25#include <mach/regs-gpio.h>
  26
  27#include "samsung.h"
  28
  29static int s3c2412_serial_setsource(struct uart_port *port,
  30                                     struct s3c24xx_uart_clksrc *clk)
  31{
  32        unsigned long ucon = rd_regl(port, S3C2410_UCON);
  33
  34        ucon &= ~S3C2412_UCON_CLKMASK;
  35
  36        if (strcmp(clk->name, "uclk") == 0)
  37                ucon |= S3C2440_UCON_UCLK;
  38        else if (strcmp(clk->name, "pclk") == 0)
  39                ucon |= S3C2440_UCON_PCLK;
  40        else if (strcmp(clk->name, "usysclk") == 0)
  41                ucon |= S3C2412_UCON_USYSCLK;
  42        else {
  43                printk(KERN_ERR "unknown clock source %s\n", clk->name);
  44                return -EINVAL;
  45        }
  46
  47        wr_regl(port, S3C2410_UCON, ucon);
  48        return 0;
  49}
  50
  51
  52static int s3c2412_serial_getsource(struct uart_port *port,
  53                                    struct s3c24xx_uart_clksrc *clk)
  54{
  55        unsigned long ucon = rd_regl(port, S3C2410_UCON);
  56
  57        switch (ucon & S3C2412_UCON_CLKMASK) {
  58        case S3C2412_UCON_UCLK:
  59                clk->divisor = 1;
  60                clk->name = "uclk";
  61                break;
  62
  63        case S3C2412_UCON_PCLK:
  64        case S3C2412_UCON_PCLK2:
  65                clk->divisor = 1;
  66                clk->name = "pclk";
  67                break;
  68
  69        case S3C2412_UCON_USYSCLK:
  70                clk->divisor = 1;
  71                clk->name = "usysclk";
  72                break;
  73        }
  74
  75        return 0;
  76}
  77
  78static int s3c2412_serial_resetport(struct uart_port *port,
  79                                    struct s3c2410_uartcfg *cfg)
  80{
  81        unsigned long ucon = rd_regl(port, S3C2410_UCON);
  82
  83        dbg("%s: port=%p (%08lx), cfg=%p\n",
  84            __func__, port, port->mapbase, cfg);
  85
  86        /* ensure we don't change the clock settings... */
  87
  88        ucon &= S3C2412_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 s3c2412_uart_inf = {
 102        .name           = "Samsung S3C2412 UART",
 103        .type           = PORT_S3C2412,
 104        .fifosize       = 64,
 105        .rx_fifomask    = S3C2440_UFSTAT_RXMASK,
 106        .rx_fifoshift   = S3C2440_UFSTAT_RXSHIFT,
 107        .rx_fifofull    = S3C2440_UFSTAT_RXFULL,
 108        .tx_fifofull    = S3C2440_UFSTAT_TXFULL,
 109        .tx_fifomask    = S3C2440_UFSTAT_TXMASK,
 110        .tx_fifoshift   = S3C2440_UFSTAT_TXSHIFT,
 111        .get_clksrc     = s3c2412_serial_getsource,
 112        .set_clksrc     = s3c2412_serial_setsource,
 113        .reset_port     = s3c2412_serial_resetport,
 114};
 115
 116/* device management */
 117
 118static int s3c2412_serial_probe(struct platform_device *dev)
 119{
 120        dbg("s3c2440_serial_probe: dev=%p\n", dev);
 121        return s3c24xx_serial_probe(dev, &s3c2412_uart_inf);
 122}
 123
 124static struct platform_driver s3c2412_serial_drv = {
 125        .probe          = s3c2412_serial_probe,
 126        .remove         = s3c24xx_serial_remove,
 127        .driver         = {
 128                .name   = "s3c2412-uart",
 129                .owner  = THIS_MODULE,
 130        },
 131};
 132
 133s3c24xx_console_init(&s3c2412_serial_drv, &s3c2412_uart_inf);
 134
 135static inline int s3c2412_serial_init(void)
 136{
 137        return s3c24xx_serial_init(&s3c2412_serial_drv, &s3c2412_uart_inf);
 138}
 139
 140static inline void s3c2412_serial_exit(void)
 141{
 142        platform_driver_unregister(&s3c2412_serial_drv);
 143}
 144
 145module_init(s3c2412_serial_init);
 146module_exit(s3c2412_serial_exit);
 147
 148MODULE_DESCRIPTION("Samsung S3C2412,S3C2413 SoC Serial port driver");
 149MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 150MODULE_LICENSE("GPL v2");
 151MODULE_ALIAS("platform:s3c2412-uart");
 152