2 * Copyright (c) 2016, Xilinx Inc.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
8 * 1. Redistributions of source code must retain the above copyright notice,
9 * this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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18 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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25 * POSSIBILITY OF SUCH DAMAGE.
28 #include <drivers/cdns_uart.h>
31 #include <mm/core_mmu.h>
34 #define CDNS_UART_CONTROL 0
35 #define CDNS_UART_MODE 4
36 #define CDNS_UART_IEN 8
37 #define CDNS_UART_IRQ_STATUS 0x14
38 #define CDNS_UART_CHANNEL_STATUS 0x2c
39 #define CDNS_UART_FIFO 0x30
41 #define CDNS_UART_CONTROL_RXRES BIT(0)
42 #define CDNS_UART_CONTROL_TXRES BIT(1)
43 #define CDNS_UART_CONTROL_RXEN BIT(2)
44 #define CDNS_UART_CONTROL_TXEN BIT(4)
46 #define CDNS_UART_MODE_8BIT (0 << 1)
47 #define CDNS_UART_MODE_PARITY_NONE (0x4 << 3)
48 #define CDNS_UART_MODE_1STP (0 << 6)
50 #define CDNS_UART_CHANNEL_STATUS_TFUL BIT(4)
51 #define CDNS_UART_CHANNEL_STATUS_TEMPTY BIT(3)
52 #define CDNS_UART_CHANNEL_STATUS_REMPTY BIT(1)
54 #define CDNS_UART_IRQ_RXTRIG BIT(0)
55 #define CDNS_UART_IRQ_RXTOUT BIT(8)
57 static vaddr_t chip_to_base(struct serial_chip *chip)
59 struct cdns_uart_data *pd =
60 container_of(chip, struct cdns_uart_data, chip);
62 return io_pa_or_va(&pd->base);
65 static void cdns_uart_flush(struct serial_chip *chip)
67 vaddr_t base = chip_to_base(chip);
69 while (!(read32(base + CDNS_UART_CHANNEL_STATUS) &
70 CDNS_UART_CHANNEL_STATUS_TEMPTY))
74 static bool cdns_uart_have_rx_data(struct serial_chip *chip)
76 vaddr_t base = chip_to_base(chip);
78 return !(read32(base + CDNS_UART_CHANNEL_STATUS) &
79 CDNS_UART_CHANNEL_STATUS_REMPTY);
82 static int cdns_uart_getchar(struct serial_chip *chip)
84 vaddr_t base = chip_to_base(chip);
86 while (!cdns_uart_have_rx_data(chip))
88 return read32(base + CDNS_UART_FIFO) & 0xff;
91 static void cdns_uart_putc(struct serial_chip *chip, int ch)
93 vaddr_t base = chip_to_base(chip);
95 /* Wait until there is space in the FIFO */
96 while (read32(base + CDNS_UART_CHANNEL_STATUS) &
97 CDNS_UART_CHANNEL_STATUS_TFUL)
100 /* Send the character */
101 write32(ch, base + CDNS_UART_FIFO);
105 static const struct serial_ops cdns_uart_ops = {
106 .flush = cdns_uart_flush,
107 .getchar = cdns_uart_getchar,
108 .have_rx_data = cdns_uart_have_rx_data,
109 .putc = cdns_uart_putc,
111 KEEP_PAGER(cdns_uart_ops);
114 * we rely on the bootloader having set up the HW correctly, we just enable
115 * transmitter/receiver here, just in case.
117 void cdns_uart_init(struct cdns_uart_data *pd, paddr_t base, uint32_t uart_clk,
121 pd->chip.ops = &cdns_uart_ops;
123 if (!uart_clk || !baud_rate)
126 /* Enable UART and RX/TX */
127 write32(CDNS_UART_CONTROL_RXEN | CDNS_UART_CONTROL_TXEN,
128 base + CDNS_UART_CONTROL);
130 cdns_uart_flush(&pd->chip);