drivers/serial/serial_xuartlite.c

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