LXR uboot/drivers/serial/altera

   1/*
   2 * (C) Copyright 2004, Psyent Corporation <www.psyent.com>
   3 * Scott McNutt <smcnutt@psyent.com>
   4 *
   5 * SPDX-License-Identifier:     GPL-2.0+
   6 */
   7
   8#include <common.h>
   9#include <dm.h>
  10#include <errno.h>
  11#include <serial.h>
  12#include <asm/io.h>
  13
  14DECLARE_GLOBAL_DATA_PTR;
  15
  16/* status register */
  17#define ALTERA_UART_TMT         BIT(5)  /* tx empty */
  18#define ALTERA_UART_TRDY        BIT(6)  /* tx ready */
  19#define ALTERA_UART_RRDY        BIT(7)  /* rx ready */
  20
  21struct altera_uart_regs {
  22        u32     rxdata;         /* Rx data reg */
  23        u32     txdata;         /* Tx data reg */
  24        u32     status;         /* Status reg */
  25        u32     control;        /* Control reg */
  26        u32     divisor;        /* Baud rate divisor reg */
  27        u32     endofpacket;    /* End-of-packet reg */
  28};
  29
  30struct altera_uart_platdata {
  31        struct altera_uart_regs *regs;
  32        unsigned int uartclk;
  33};
  34
  35static int altera_uart_setbrg(struct udevice *dev, int baudrate)
  36{
  37        struct altera_uart_platdata *plat = dev->platdata;
  38        struct altera_uart_regs *const regs = plat->regs;
  39        u32 div;
  40
  41        div = (plat->uartclk / baudrate) - 1;
  42        writel(div, &regs->divisor);
  43
  44        return 0;
  45}
  46
  47static int altera_uart_putc(struct udevice *dev, const char ch)
  48{
  49        struct altera_uart_platdata *plat = dev->platdata;
  50        struct altera_uart_regs *const regs = plat->regs;
  51
  52        if (!(readl(&regs->status) & ALTERA_UART_TRDY))
  53                return -EAGAIN;
  54
  55        writel(ch, &regs->txdata);
  56
  57        return 0;
  58}
  59
  60static int altera_uart_pending(struct udevice *dev, bool input)
  61{
  62        struct altera_uart_platdata *plat = dev->platdata;
  63        struct altera_uart_regs *const regs = plat->regs;
  64        u32 st = readl(&regs->status);
  65
  66        if (input)
  67                return st & ALTERA_UART_RRDY ? 1 : 0;
  68        else
  69                return !(st & ALTERA_UART_TMT);
  70}
  71
  72static int altera_uart_getc(struct udevice *dev)
  73{
  74        struct altera_uart_platdata *plat = dev->platdata;
  75        struct altera_uart_regs *const regs = plat->regs;
  76
  77        if (!(readl(&regs->status) & ALTERA_UART_RRDY))
  78                return -EAGAIN;
  79
  80        return readl(&regs->rxdata) & 0xff;
  81}
  82
  83static int altera_uart_probe(struct udevice *dev)
  84{
  85        return 0;
  86}
  87
  88static int altera_uart_ofdata_to_platdata(struct udevice *dev)
  89{
  90        struct altera_uart_platdata *plat = dev_get_platdata(dev);
  91
  92        plat->regs = map_physmem(dev_get_addr(dev),
  93                                 sizeof(struct altera_uart_regs),
  94                                 MAP_NOCACHE);
  95        plat->uartclk = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
  96                "clock-frequency", 0);
  97
  98        return 0;
  99}
 100
 101static const struct dm_serial_ops altera_uart_ops = {
 102        .putc = altera_uart_putc,
 103        .pending = altera_uart_pending,
 104        .getc = altera_uart_getc,
 105        .setbrg = altera_uart_setbrg,
 106};
 107
 108static const struct udevice_id altera_uart_ids[] = {
 109        { .compatible = "altr,uart-1.0" },
 110        {}
 111};
 112
 113U_BOOT_DRIVER(altera_uart) = {
 114        .name   = "altera_uart",
 115        .id     = UCLASS_SERIAL,
 116        .of_match = altera_uart_ids,
 117        .ofdata_to_platdata = altera_uart_ofdata_to_platdata,
 118        .platdata_auto_alloc_size = sizeof(struct altera_uart_platdata),
 119        .probe = altera_uart_probe,
 120        .ops    = &altera_uart_ops,
 121        .flags = DM_FLAG_PRE_RELOC,
 122};
 123
 124#ifdef CONFIG_DEBUG_UART_ALTERA_UART
 125
 126#include <debug_uart.h>
 127
 128static inline void _debug_uart_init(void)
 129{
 130        struct altera_uart_regs *regs = (void *)CONFIG_DEBUG_UART_BASE;
 131        u32 div;
 132
 133        div = (CONFIG_DEBUG_UART_CLOCK / CONFIG_BAUDRATE) - 1;
 134        writel(div, &regs->divisor);
 135}
 136
 137static inline void _debug_uart_putc(int ch)
 138{
 139        struct altera_uart_regs *regs = (void *)CONFIG_DEBUG_UART_BASE;
 140
 141        while (1) {
 142                u32 st = readl(&regs->status);
 143
 144                if (st & ALTERA_UART_TRDY)
 145                        break;
 146        }
 147
 148        writel(ch, &regs->txdata);
 149}
 150
 151DEBUG_UART_FUNCS
 152
 153#endif
 154