arch/arm/mach-omap2/serial.c

   1 /*
   2  * arch/arm/mach-omap2/serial.c
   3  *
   4  * OMAP2 serial support.
   5  *
   6  * Copyright (C) 2005-2008 Nokia Corporation
   7  * Author: Paul Mundt <paul.mundt@nokia.com>
   8  *
   9  * Based off of arch/arm/mach-omap/omap1/serial.c
  10  *
  11  * This file is subject to the terms and conditions of the GNU General Public
  12  * License. See the file "COPYING" in the main directory of this archive
  13  * for more details.
  14  */
  15 #include <linux/kernel.h>
  16 #include <linux/init.h>
  17 #include <linux/serial_8250.h>
  18 #include <linux/serial_reg.h>
  19 #include <linux/clk.h>
  20
  21 #include <asm/io.h>
  22
  23 #include <asm/arch/common.h>
  24 #include <asm/arch/board.h>
  25
  26 static struct clk *uart_ick[OMAP_MAX_NR_PORTS];
  27 static struct clk *uart_fck[OMAP_MAX_NR_PORTS];
  28
  29 static struct plat_serial8250_port serial_platform_data[] = {
  30         {
  31                 .membase        = (char *)IO_ADDRESS(OMAP_UART1_BASE),
  32                 .mapbase        = (unsigned long)OMAP_UART1_BASE,
  33                 .irq            = 72,
  34                 .flags          = UPF_BOOT_AUTOCONF,
  35                 .iotype         = UPIO_MEM,
  36                 .regshift       = 2,
  37                 .uartclk        = OMAP24XX_BASE_BAUD * 16,
  38         }, {
  39                 .membase        = (char *)IO_ADDRESS(OMAP_UART2_BASE),
  40                 .mapbase        = (unsigned long)OMAP_UART2_BASE,
  41                 .irq            = 73,
  42                 .flags          = UPF_BOOT_AUTOCONF,
  43                 .iotype         = UPIO_MEM,
  44                 .regshift       = 2,
  45                 .uartclk        = OMAP24XX_BASE_BAUD * 16,
  46         }, {
  47                 .membase        = (char *)IO_ADDRESS(OMAP_UART3_BASE),
  48                 .mapbase        = (unsigned long)OMAP_UART3_BASE,
  49                 .irq            = 74,
  50                 .flags          = UPF_BOOT_AUTOCONF,
  51                 .iotype         = UPIO_MEM,
  52                 .regshift       = 2,
  53                 .uartclk        = OMAP24XX_BASE_BAUD * 16,
  54         }, {
  55                 .flags          = 0
  56         }
  57 };
  58
  59 static inline unsigned int serial_read_reg(struct plat_serial8250_port *up,
  60                                            int offset)
  61 {
  62         offset <<= up->regshift;
  63         return (unsigned int)__raw_readb(up->membase + offset);
  64 }
  65
  66 static inline void serial_write_reg(struct plat_serial8250_port *p, int offset,
  67                                     int value)
  68 {
  69         offset <<= p->regshift;
  70         __raw_writeb(value, (unsigned long)(p->membase + offset));
  71 }
  72
  73 /*
  74  * Internal UARTs need to be initialized for the 8250 autoconfig to work
  75  * properly. Note that the TX watermark initialization may not be needed
  76  * once the 8250.c watermark handling code is merged.
  77  */
  78 static inline void __init omap_serial_reset(struct plat_serial8250_port *p)
  79 {
  80         serial_write_reg(p, UART_OMAP_MDR1, 0x07);
  81         serial_write_reg(p, UART_OMAP_SCR, 0x08);
  82         serial_write_reg(p, UART_OMAP_MDR1, 0x00);
  83         serial_write_reg(p, UART_OMAP_SYSC, (0x02 << 3) | (1 << 2) | (1 << 0));
  84 }
  85
  86 void omap_serial_enable_clocks(int enable)
  87 {
  88         int i;
  89         for (i = 0; i < OMAP_MAX_NR_PORTS; i++) {
  90                 if (uart_ick[i])
  91                         enable ? clk_enable(uart_ick[i]) :
  92                                 clk_disable(uart_ick[i]);
  93                 if (uart_fck[i])
  94                         enable ? clk_enable(uart_fck[i]) :
  95                                 clk_disable(uart_fck[i]);
  96         }
  97 }
  98
  99 void __init omap_serial_init(void)
 100 {
 101         int i;
 102         const struct omap_uart_config *info;
 103         char name[16];
 104
 105         /*
 106          * Make sure the serial ports are muxed on at this point.
 107          * You have to mux them off in device drivers later on
 108          * if not needed.
 109          */
 110
 111         info = omap_get_config(OMAP_TAG_UART, struct omap_uart_config);
 112
 113         if (info == NULL)
 114                 return;
 115
 116         for (i = 0; i < OMAP_MAX_NR_PORTS; i++) {
 117                 struct plat_serial8250_port *p = serial_platform_data + i;
 118
 119                 if (!(info->enabled_uarts & (1 << i))) {
 120                         p->membase = 0;
 121                         p->mapbase = 0;
 122                         continue;
 123                 }
 124
 125                 sprintf(name, "uart%d_ick", i+1);
 126                 uart_ick[i] = clk_get(NULL, name);
 127                 if (IS_ERR(uart_ick[i])) {
 128                         printk(KERN_ERR "Could not get uart%d_ick\n", i+1);
 129                         uart_ick[i] = NULL;
 130                 }
 131                 else
 132                         clk_enable(uart_ick[i]);
 133                 sprintf(name, "uart%d_fck", i+1);
 134                 uart_fck[i] = clk_get(NULL, name);
 135                 if (IS_ERR(uart_fck[i])) {
 136                         printk(KERN_ERR "Could not get uart%d_fck\n", i+1);
 137                         uart_ick[i] = NULL;
 138                 }
 139                 else
 140                         clk_enable(uart_fck[i]);
 141
 142                 omap_serial_reset(p);
 143         }
 144 }
 145
 146 static struct platform_device serial_device = {
 147         .name                   = "serial8250",
 148         .id                     = PLAT8250_DEV_PLATFORM,
 149         .dev                    = {
 150                 .platform_data  = serial_platform_data,
 151         },
 152 };
 153
 154 static int __init omap_init(void)
 155 {
 156         return platform_device_register(&serial_device);
 157 }
 158 arch_initcall(omap_init);