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
  29 static 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
  52 static 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
  78 static 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
 101 static 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
 118 static 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
 124 static struct platform_driver s3c2412_serial_driver = {
 125         .probe          = s3c2412_serial_probe,
 126         .remove         = __devexit_p(s3c24xx_serial_remove),
 127         .driver         = {
 128                 .name   = "s3c2412-uart",
 129                 .owner  = THIS_MODULE,
 130         },
 131 };
 132
 133 s3c24xx_console_init(&s3c2412_serial_driver, &s3c2412_uart_inf);
 134
 135 static inline int s3c2412_serial_init(void)
 136 {
 137         return s3c24xx_serial_init(&s3c2412_serial_driver, &s3c2412_uart_inf);
 138 }
 139
 140 static inline void s3c2412_serial_exit(void)
 141 {
 142         platform_driver_unregister(&s3c2412_serial_driver);
 143 }
 144
 145 module_init(s3c2412_serial_init);
 146 module_exit(s3c2412_serial_exit);
 147
 148 MODULE_DESCRIPTION("Samsung S3C2412,S3C2413 SoC Serial port driver");
 149 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 150 MODULE_LICENSE("GPL v2");
 151 MODULE_ALIAS("platform:s3c2412-uart");