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192.168.1.100 / T108 / e958203796650e3959a43708d67534bf36f4c83b / . / marvell / linux / arch / mips / ath79 / early_printk.c
blob: 782732cd1a2bd21ce049422f41d25a5d8b628b93 [file] [log] [blame]
b.liue9582032025-04-17 19:18:16 +0800[diff] [blame^]1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Atheros AR7XXX/AR9XXX SoC early printk support
4 *
5 * Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
6 * Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
7 */
8
9#include <linux/io.h>
10#include <linux/errno.h>
11#include <linux/serial_reg.h>
12#include <asm/addrspace.h>
13#include <asm/setup.h>
14
15#include <asm/mach-ath79/ath79.h>
16#include <asm/mach-ath79/ar71xx_regs.h>
17#include <asm/mach-ath79/ar933x_uart.h>
18
19static void (*_prom_putchar)(char);
20
21static inline void prom_putchar_wait(void __iomem *reg, u32 mask, u32 val)
22{
23 u32 t;
24
25 do {
26 t = __raw_readl(reg);
27 if ((t & mask) == val)
28 break;
29 } while (1);
30}
31
32#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
33
34static void prom_putchar_ar71xx(char ch)
35{
36 void __iomem *base = (void __iomem *)(KSEG1ADDR(AR71XX_UART_BASE));
37
38 prom_putchar_wait(base + UART_LSR * 4, BOTH_EMPTY, BOTH_EMPTY);
39 __raw_writel((unsigned char)ch, base + UART_TX * 4);
40 prom_putchar_wait(base + UART_LSR * 4, BOTH_EMPTY, BOTH_EMPTY);
41}
42
43static void prom_putchar_ar933x(char ch)
44{
45 void __iomem *base = (void __iomem *)(KSEG1ADDR(AR933X_UART_BASE));
46
47 prom_putchar_wait(base + AR933X_UART_DATA_REG, AR933X_UART_DATA_TX_CSR,
48 AR933X_UART_DATA_TX_CSR);
49 __raw_writel(AR933X_UART_DATA_TX_CSR | (unsigned char)ch,
50 base + AR933X_UART_DATA_REG);
51 prom_putchar_wait(base + AR933X_UART_DATA_REG, AR933X_UART_DATA_TX_CSR,
52 AR933X_UART_DATA_TX_CSR);
53}
54
55static void prom_putchar_dummy(char ch)
56{
57 /* nothing to do */
58}
59
60static void prom_enable_uart(u32 id)
61{
62 void __iomem *gpio_base;
63 u32 uart_en;
64 u32 t;
65
66 switch (id) {
67 case REV_ID_MAJOR_AR71XX:
68 uart_en = AR71XX_GPIO_FUNC_UART_EN;
69 break;
70
71 case REV_ID_MAJOR_AR7240:
72 case REV_ID_MAJOR_AR7241:
73 case REV_ID_MAJOR_AR7242:
74 uart_en = AR724X_GPIO_FUNC_UART_EN;
75 break;
76
77 case REV_ID_MAJOR_AR913X:
78 uart_en = AR913X_GPIO_FUNC_UART_EN;
79 break;
80
81 case REV_ID_MAJOR_AR9330:
82 case REV_ID_MAJOR_AR9331:
83 uart_en = AR933X_GPIO_FUNC_UART_EN;
84 break;
85
86 case REV_ID_MAJOR_AR9341:
87 case REV_ID_MAJOR_AR9342:
88 case REV_ID_MAJOR_AR9344:
89 /* TODO */
90 default:
91 return;
92 }
93
94 gpio_base = (void __iomem *)KSEG1ADDR(AR71XX_GPIO_BASE);
95 t = __raw_readl(gpio_base + AR71XX_GPIO_REG_FUNC);
96 t |= uart_en;
97 __raw_writel(t, gpio_base + AR71XX_GPIO_REG_FUNC);
98}
99
100static void prom_putchar_init(void)
101{
102 void __iomem *base;
103 u32 id;
104
105 base = (void __iomem *)(KSEG1ADDR(AR71XX_RESET_BASE));
106 id = __raw_readl(base + AR71XX_RESET_REG_REV_ID);
107 id &= REV_ID_MAJOR_MASK;
108
109 switch (id) {
110 case REV_ID_MAJOR_AR71XX:
111 case REV_ID_MAJOR_AR7240:
112 case REV_ID_MAJOR_AR7241:
113 case REV_ID_MAJOR_AR7242:
114 case REV_ID_MAJOR_AR913X:
115 case REV_ID_MAJOR_AR9341:
116 case REV_ID_MAJOR_AR9342:
117 case REV_ID_MAJOR_AR9344:
118 case REV_ID_MAJOR_QCA9533:
119 case REV_ID_MAJOR_QCA9533_V2:
120 case REV_ID_MAJOR_QCA9556:
121 case REV_ID_MAJOR_QCA9558:
122 case REV_ID_MAJOR_TP9343:
123 case REV_ID_MAJOR_QCA956X:
124 _prom_putchar = prom_putchar_ar71xx;
125 break;
126
127 case REV_ID_MAJOR_AR9330:
128 case REV_ID_MAJOR_AR9331:
129 _prom_putchar = prom_putchar_ar933x;
130 break;
131
132 default:
133 _prom_putchar = prom_putchar_dummy;
134 return;
135 }
136
137 prom_enable_uart(id);
138}
139
140void prom_putchar(char ch)
141{
142 if (!_prom_putchar)
143 prom_putchar_init();
144
145 _prom_putchar(ch);
146}