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