2 * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
12 #include <asm/global_data.h>
14 DECLARE_GLOBAL_DATA_PTR;
16 struct arc_serial_regs {
27 struct arc_serial_plat {
28 struct arc_serial_regs *reg;
32 /* Bit definitions of STATUS register */
33 #define UART_RXEMPTY (1 << 5)
34 #define UART_OVERFLOW_ERR (1 << 1)
35 #define UART_TXEMPTY (1 << 7)
37 static int arc_serial_setbrg(struct udevice *dev, int baudrate)
39 struct arc_serial_plat *plat = dev_get_plat(dev);
40 struct arc_serial_regs *const regs = plat->reg;
41 int arc_console_baud = gd->cpu_clk / (baudrate * 4) - 1;
43 writeb(arc_console_baud & 0xff, ®s->baudl);
44 writeb((arc_console_baud & 0xff00) >> 8, ®s->baudh);
49 static int arc_serial_putc(struct udevice *dev, const char c)
51 struct arc_serial_plat *plat = dev_get_plat(dev);
52 struct arc_serial_regs *const regs = plat->reg;
54 if (!(readb(®s->status) & UART_TXEMPTY))
57 writeb(c, ®s->data);
62 static int arc_serial_tstc(struct arc_serial_regs *const regs)
64 return !(readb(®s->status) & UART_RXEMPTY);
67 static int arc_serial_pending(struct udevice *dev, bool input)
69 struct arc_serial_plat *plat = dev_get_plat(dev);
70 struct arc_serial_regs *const regs = plat->reg;
71 uint32_t status = readb(®s->status);
74 return status & UART_RXEMPTY ? 0 : 1;
76 return status & UART_TXEMPTY ? 0 : 1;
79 static int arc_serial_getc(struct udevice *dev)
81 struct arc_serial_plat *plat = dev_get_plat(dev);
82 struct arc_serial_regs *const regs = plat->reg;
84 if (!arc_serial_tstc(regs))
87 /* Check for overflow errors */
88 if (readb(®s->status) & UART_OVERFLOW_ERR)
91 return readb(®s->data) & 0xFF;
94 static int arc_serial_probe(struct udevice *dev)
99 static const struct dm_serial_ops arc_serial_ops = {
100 .putc = arc_serial_putc,
101 .pending = arc_serial_pending,
102 .getc = arc_serial_getc,
103 .setbrg = arc_serial_setbrg,
106 static const struct udevice_id arc_serial_ids[] = {
107 { .compatible = "snps,arc-uart" },
111 static int arc_serial_of_to_plat(struct udevice *dev)
113 struct arc_serial_plat *plat = dev_get_plat(dev);
114 DECLARE_GLOBAL_DATA_PTR;
116 plat->reg = dev_read_addr_ptr(dev);
117 plat->uartclk = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
118 "clock-frequency", 0);
123 U_BOOT_DRIVER(serial_arc) = {
124 .name = "serial_arc",
126 .of_match = arc_serial_ids,
127 .of_to_plat = arc_serial_of_to_plat,
128 .plat_auto = sizeof(struct arc_serial_plat),
129 .probe = arc_serial_probe,
130 .ops = &arc_serial_ops,
133 #ifdef CONFIG_DEBUG_ARC_SERIAL
134 #include <debug_uart.h>
136 static inline void _debug_uart_init(void)
138 struct arc_serial_regs *regs = (struct arc_serial_regs *)CONFIG_VAL(DEBUG_UART_BASE);
139 int arc_console_baud = CONFIG_DEBUG_UART_CLOCK / (CONFIG_BAUDRATE * 4) - 1;
141 writeb(arc_console_baud & 0xff, ®s->baudl);
142 writeb((arc_console_baud & 0xff00) >> 8, ®s->baudh);
145 static inline void _debug_uart_putc(int c)
147 struct arc_serial_regs *regs = (struct arc_serial_regs *)CONFIG_VAL(DEBUG_UART_BASE);
149 while (!(readb(®s->status) & UART_TXEMPTY))
152 writeb(c, ®s->data);