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 <asm/io.h> 12 #include <linux/compiler.h> 13 #include <serial.h> 14 15 struct altera_uart_regs { 16 u32 rxdata; /* Rx data reg */ 17 u32 txdata; /* Tx data reg */ 18 u32 status; /* Status reg */ 19 u32 control; /* Control reg */ 20 u32 divisor; /* Baud rate divisor reg */ 21 u32 endofpacket; /* End-of-packet reg */ 22 }; 23 24 struct altera_uart_platdata { 25 struct altera_uart_regs *regs; 26 unsigned int uartclk; 27 }; 28 29 /* status register */ 30 #define ALTERA_UART_TMT (1 << 5) /* tx empty */ 31 #define ALTERA_UART_TRDY (1 << 6) /* tx ready */ 32 #define ALTERA_UART_RRDY (1 << 7) /* rx ready */ 33 34 DECLARE_GLOBAL_DATA_PTR; 35 36 static int altera_uart_setbrg(struct udevice *dev, int baudrate) 37 { 38 struct altera_uart_platdata *plat = dev->platdata; 39 struct altera_uart_regs *const regs = plat->regs; 40 u32 div; 41 42 div = (plat->uartclk / baudrate) - 1; 43 writel(div, ®s->divisor); 44 45 return 0; 46 } 47 48 static int altera_uart_putc(struct udevice *dev, const char ch) 49 { 50 struct altera_uart_platdata *plat = dev->platdata; 51 struct altera_uart_regs *const regs = plat->regs; 52 53 if (!(readl(®s->status) & ALTERA_UART_TRDY)) 54 return -EAGAIN; 55 56 writel(ch, ®s->txdata); 57 58 return 0; 59 } 60 61 static int altera_uart_pending(struct udevice *dev, bool input) 62 { 63 struct altera_uart_platdata *plat = dev->platdata; 64 struct altera_uart_regs *const regs = plat->regs; 65 u32 st = readl(®s->status); 66 67 if (input) 68 return st & ALTERA_UART_RRDY ? 1 : 0; 69 else 70 return !(st & ALTERA_UART_TMT); 71 } 72 73 static int altera_uart_getc(struct udevice *dev) 74 { 75 struct altera_uart_platdata *plat = dev->platdata; 76 struct altera_uart_regs *const regs = plat->regs; 77 78 if (!(readl(®s->status) & ALTERA_UART_RRDY)) 79 return -EAGAIN; 80 81 return readl(®s->rxdata) & 0xff; 82 } 83 84 static int altera_uart_probe(struct udevice *dev) 85 { 86 return 0; 87 } 88 89 static int altera_uart_ofdata_to_platdata(struct udevice *dev) 90 { 91 struct altera_uart_platdata *plat = dev_get_platdata(dev); 92 93 plat->regs = ioremap(dev_get_addr(dev), 94 sizeof(struct altera_uart_regs)); 95 plat->uartclk = fdtdec_get_int(gd->fdt_blob, dev->of_offset, 96 "clock-frequency", 0); 97 98 return 0; 99 } 100 101 static 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 }; 107 108 static const struct udevice_id altera_uart_ids[] = { 109 { .compatible = "altr,uart-1.0", }, 110 { } 111 }; 112 113 U_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> 127 128 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, ®s->divisor); 135 } 136 137 static 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(®s->status); 143 144 if (st & ALTERA_UART_TRDY) 145 break; 146 } 147 148 writel(ch, ®s->txdata); 149 } 150 151 DEBUG_UART_FUNCS 152 153 #endif 154