arch/arm/cpu/arm926ejs/lpc32xx/devices.c

   1 /*
   2  * Copyright (C) 2011 by Vladimir Zapolskiy <vz@mleia.com>
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #include <common.h>
   8 #include <asm/arch/cpu.h>
   9 #include <asm/arch/clk.h>
  10 #include <asm/arch/uart.h>
  11 #include <asm/io.h>
  12
  13 static struct clk_pm_regs    *clk  = (struct clk_pm_regs *)CLK_PM_BASE;
  14 static struct uart_ctrl_regs *ctrl = (struct uart_ctrl_regs *)UART_CTRL_BASE;
  15
  16 void lpc32xx_uart_init(unsigned int uart_id)
  17 {
  18         if (uart_id < 1 || uart_id > 7)
  19                 return;
  20
  21         /* Disable loopback mode, if it is set by S1L bootloader */
  22         clrbits_le32(&ctrl->loop,
  23                      UART_LOOPBACK(CONFIG_SYS_LPC32XX_UART));
  24
  25         if (uart_id < 3 || uart_id > 6)
  26                 return;
  27
  28         /* Enable UART system clock */
  29         setbits_le32(&clk->uartclk_ctrl, CLK_UART(uart_id));
  30
  31         /* Set UART into autoclock mode */
  32         clrsetbits_le32(&ctrl->clkmode,
  33                         UART_CLKMODE_MASK(uart_id),
  34                         UART_CLKMODE_AUTO(uart_id));
  35
  36         /* Bypass pre-divider of UART clock */
  37         writel(CLK_UART_X_DIV(1) | CLK_UART_Y_DIV(1),
  38                &clk->u3clk + (uart_id - 3));
  39 }