drivers/serial/serial_xuartlite.c

   1 /*
   2  * (C) Copyright 2008 - 2015 Michal Simek <monstr@monstr.eu>
   3  * Clean driver and add xilinx constant from header file
   4  *
   5  * (C) Copyright 2004 Atmark Techno, Inc.
   6  * Yasushi SHOJI <yashi@atmark-techno.com>
   7  *
   8  * SPDX-License-Identifier:     GPL-2.0+
   9  */
  10
  11 #include <config.h>
  12 #include <common.h>
  13 #include <dm.h>
  14 #include <asm/io.h>
  15 #include <linux/compiler.h>
  16 #include <serial.h>
  17
  18 DECLARE_GLOBAL_DATA_PTR;
  19
  20 #define SR_TX_FIFO_FULL         BIT(3) /* transmit FIFO full */
  21 #define SR_TX_FIFO_EMPTY        BIT(2) /* transmit FIFO empty */
  22 #define SR_RX_FIFO_VALID_DATA   BIT(0) /* data in receive FIFO */
  23 #define SR_RX_FIFO_FULL         BIT(1) /* receive FIFO full */
  24
  25 #define ULITE_CONTROL_RST_TX    0x01
  26 #define ULITE_CONTROL_RST_RX    0x02
  27
  28 struct uartlite {
  29         unsigned int rx_fifo;
  30         unsigned int tx_fifo;
  31         unsigned int status;
  32         unsigned int control;
  33 };
  34
  35 struct uartlite_platdata {
  36         struct uartlite *regs;
  37 };
  38
  39 static int uartlite_serial_putc(struct udevice *dev, const char ch)
  40 {
  41         struct uartlite_platdata *plat = dev_get_platdata(dev);
  42         struct uartlite *regs = plat->regs;
  43
  44         if (in_be32(&regs->status) & SR_TX_FIFO_FULL)
  45                 return -EAGAIN;
  46
  47         out_be32(&regs->tx_fifo, ch & 0xff);
  48
  49         return 0;
  50 }
  51
  52 static int uartlite_serial_getc(struct udevice *dev)
  53 {
  54         struct uartlite_platdata *plat = dev_get_platdata(dev);
  55         struct uartlite *regs = plat->regs;
  56
  57         if (!(in_be32(&regs->status) & SR_RX_FIFO_VALID_DATA))
  58                 return -EAGAIN;
  59
  60         return in_be32(&regs->rx_fifo) & 0xff;
  61 }
  62
  63 static int uartlite_serial_pending(struct udevice *dev, bool input)
  64 {
  65         struct uartlite_platdata *plat = dev_get_platdata(dev);
  66         struct uartlite *regs = plat->regs;
  67
  68         if (input)
  69                 return in_be32(&regs->status) & SR_RX_FIFO_VALID_DATA;
  70
  71         return !(in_be32(&regs->status) & SR_TX_FIFO_EMPTY);
  72 }
  73
  74 static int uartlite_serial_probe(struct udevice *dev)
  75 {
  76         struct uartlite_platdata *plat = dev_get_platdata(dev);
  77         struct uartlite *regs = plat->regs;
  78
  79         out_be32(&regs->control, 0);
  80         out_be32(&regs->control, ULITE_CONTROL_RST_RX | ULITE_CONTROL_RST_TX);
  81         in_be32(&regs->control);
  82
  83         return 0;
  84 }
  85
  86 static int uartlite_serial_ofdata_to_platdata(struct udevice *dev)
  87 {
  88         struct uartlite_platdata *plat = dev_get_platdata(dev);
  89
  90         plat->regs = (struct uartlite *)devfdt_get_addr(dev);
  91
  92         return 0;
  93 }
  94
  95 static const struct dm_serial_ops uartlite_serial_ops = {
  96         .putc = uartlite_serial_putc,
  97         .pending = uartlite_serial_pending,
  98         .getc = uartlite_serial_getc,
  99 };
 100
 101 static const struct udevice_id uartlite_serial_ids[] = {
 102         { .compatible = "xlnx,opb-uartlite-1.00.b", },
 103         { .compatible = "xlnx,xps-uartlite-1.00.a" },
 104         { }
 105 };
 106
 107 U_BOOT_DRIVER(serial_uartlite) = {
 108         .name   = "serial_uartlite",
 109         .id     = UCLASS_SERIAL,
 110         .of_match = uartlite_serial_ids,
 111         .ofdata_to_platdata = uartlite_serial_ofdata_to_platdata,
 112         .platdata_auto_alloc_size = sizeof(struct uartlite_platdata),
 113         .probe = uartlite_serial_probe,
 114         .ops    = &uartlite_serial_ops,
 115         .flags = DM_FLAG_PRE_RELOC,
 116 };
 117
 118 #ifdef CONFIG_DEBUG_UART_UARTLITE
 119
 120 #include <debug_uart.h>
 121
 122 static inline void _debug_uart_init(void)
 123 {
 124         struct uartlite *regs = (struct uartlite *)CONFIG_DEBUG_UART_BASE;
 125
 126         out_be32(&regs->control, 0);
 127         out_be32(&regs->control, ULITE_CONTROL_RST_RX | ULITE_CONTROL_RST_TX);
 128         in_be32(&regs->control);
 129 }
 130
 131 static inline void _debug_uart_putc(int ch)
 132 {
 133         struct uartlite *regs = (struct uartlite *)CONFIG_DEBUG_UART_BASE;
 134
 135         while (in_be32(&regs->status) & SR_TX_FIFO_FULL)
 136                 ;
 137
 138         out_be32(&regs->tx_fifo, ch & 0xff);
 139 }
 140
 141 DEBUG_UART_FUNCS
 142 #endif