root/arch/arm/include/debug/8250.S

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * arch/arm/include/debug/8250.S
   4  *
   5  *  Copyright (C) 1994-2013 Russell King
   6  */
   7 #include <linux/serial_reg.h>
   8 
   9                 .macro  addruart, rp, rv, tmp
  10                 ldr     \rp, =CONFIG_DEBUG_UART_PHYS
  11                 ldr     \rv, =CONFIG_DEBUG_UART_VIRT
  12                 .endm
  13 
  14 #ifdef CONFIG_DEBUG_UART_8250_WORD
  15                 .macro  store, rd, rx:vararg
  16          ARM_BE8(rev \rd, \rd)
  17                 str     \rd, \rx
  18          ARM_BE8(rev \rd, \rd)
  19                 .endm
  20 
  21                 .macro  load, rd, rx:vararg
  22                 ldr     \rd, \rx
  23         ARM_BE8(rev \rd, \rd)
  24                 .endm
  25 #else
  26                 .macro  store, rd, rx:vararg
  27                 strb    \rd, \rx
  28                 .endm
  29 
  30                 .macro  load, rd, rx:vararg
  31                 ldrb    \rd, \rx
  32                 .endm
  33 #endif
  34 
  35 #define UART_SHIFT CONFIG_DEBUG_UART_8250_SHIFT
  36 
  37                 .macro  senduart,rd,rx
  38                 store   \rd, [\rx, #UART_TX << UART_SHIFT]
  39                 .endm
  40 
  41                 .macro  busyuart,rd,rx
  42 1002:           load    \rd, [\rx, #UART_LSR << UART_SHIFT]
  43                 and     \rd, \rd, #UART_LSR_TEMT | UART_LSR_THRE
  44                 teq     \rd, #UART_LSR_TEMT | UART_LSR_THRE
  45                 bne     1002b
  46                 .endm
  47 
  48                 .macro  waituart,rd,rx
  49 #ifdef CONFIG_DEBUG_UART_8250_FLOW_CONTROL
  50 1001:           load    \rd, [\rx, #UART_MSR << UART_SHIFT]
  51                 tst     \rd, #UART_MSR_CTS
  52                 beq     1001b
  53 #endif
  54                 .endm