arch/arm/mach-davinci/serial.c

   1 /*
   2  * TI DaVinci serial driver
   3  *
   4  * Copyright (C) 2006 Texas Instruments.
   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
  22 #include <linux/kernel.h>
  23 #include <linux/init.h>
  24 #include <linux/serial_8250.h>
  25 #include <linux/serial_reg.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/delay.h>
  28 #include <linux/clk.h>
  29 #include <linux/io.h>
  30
  31 #include <asm/irq.h>
  32 #include <mach/hardware.h>
  33 #include <mach/serial.h>
  34 #include <mach/irqs.h>
  35
  36 #define UART_DAVINCI_PWREMU 0x0c
  37
  38 static inline unsigned int davinci_serial_in(struct plat_serial8250_port *up,
  39                                           int offset)
  40 {
  41         offset <<= up->regshift;
  42         return (unsigned int)__raw_readb(up->membase + offset);
  43 }
  44
  45 static inline void davinci_serial_outp(struct plat_serial8250_port *p,
  46                                        int offset, int value)
  47 {
  48         offset <<= p->regshift;
  49         __raw_writeb(value, p->membase + offset);
  50 }
  51
  52 static struct plat_serial8250_port serial_platform_data[] = {
  53         {
  54                 .membase        = (char *)IO_ADDRESS(DAVINCI_UART0_BASE),
  55                 .mapbase        = (unsigned long)DAVINCI_UART0_BASE,
  56                 .irq            = IRQ_UARTINT0,
  57                 .flags          = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,
  58                 .iotype         = UPIO_MEM,
  59                 .regshift       = 2,
  60                 .uartclk        = 27000000,
  61         },
  62         {
  63                 .flags          = 0
  64         },
  65 };
  66
  67 static struct platform_device serial_device = {
  68         .name                   = "serial8250",
  69         .id                     = PLAT8250_DEV_PLATFORM,
  70         .dev                    = {
  71                 .platform_data  = serial_platform_data,
  72         },
  73 };
  74
  75 static void __init davinci_serial_reset(struct plat_serial8250_port *p)
  76 {
  77         /* reset both transmitter and receiver: bits 14,13 = UTRST, URRST */
  78         unsigned int pwremu = 0;
  79
  80         davinci_serial_outp(p, UART_IER, 0);  /* disable all interrupts */
  81
  82         davinci_serial_outp(p, UART_DAVINCI_PWREMU, pwremu);
  83         mdelay(10);
  84
  85         pwremu |= (0x3 << 13);
  86         pwremu |= 0x1;
  87         davinci_serial_outp(p, UART_DAVINCI_PWREMU, pwremu);
  88 }
  89
  90 static int __init davinci_init(void)
  91 {
  92         davinci_serial_reset(&serial_platform_data[0]);
  93         return platform_device_register(&serial_device);
  94 }
  95
  96 arch_initcall(davinci_init);