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