blob: 363affb8c5f8e2e07a83d56265c6e276ba025b68 [file] [log] [blame]
Beniamino Galvanibfcef282016-05-08 08:30:16 +02001/*
2 * (C) Copyright 2016 Beniamino Galvani <b.galvani@gmail.com>
3 *
4 * SPDX-License-Identifier: GPL-2.0+
5 */
6
7#include <common.h>
8#include <dm.h>
9#include <errno.h>
10#include <fdtdec.h>
11#include <linux/compiler.h>
12#include <serial.h>
13
14DECLARE_GLOBAL_DATA_PTR;
15
16struct meson_uart {
17 u32 wfifo;
18 u32 rfifo;
19 u32 control;
20 u32 status;
21 u32 misc;
22};
23
24struct meson_serial_platdata {
25 struct meson_uart *reg;
26};
27
28/* AML_UART_STATUS bits */
29#define AML_UART_PARITY_ERR BIT(16)
30#define AML_UART_FRAME_ERR BIT(17)
31#define AML_UART_TX_FIFO_WERR BIT(18)
32#define AML_UART_RX_EMPTY BIT(20)
33#define AML_UART_TX_FULL BIT(21)
34#define AML_UART_TX_EMPTY BIT(22)
35#define AML_UART_XMIT_BUSY BIT(25)
36#define AML_UART_ERR (AML_UART_PARITY_ERR | \
37 AML_UART_FRAME_ERR | \
38 AML_UART_TX_FIFO_WERR)
39
40/* AML_UART_CONTROL bits */
41#define AML_UART_TX_EN BIT(12)
42#define AML_UART_RX_EN BIT(13)
43#define AML_UART_TX_RST BIT(22)
44#define AML_UART_RX_RST BIT(23)
45#define AML_UART_CLR_ERR BIT(24)
46
47static void meson_serial_init(struct meson_uart *uart)
48{
49 u32 val;
50
51 val = readl(&uart->control);
52 val |= (AML_UART_RX_RST | AML_UART_TX_RST | AML_UART_CLR_ERR);
53 writel(val, &uart->control);
54 val &= ~(AML_UART_RX_RST | AML_UART_TX_RST | AML_UART_CLR_ERR);
55 writel(val, &uart->control);
56 val |= (AML_UART_RX_EN | AML_UART_TX_EN);
57 writel(val, &uart->control);
58}
59
60static int meson_serial_probe(struct udevice *dev)
61{
62 struct meson_serial_platdata *plat = dev->platdata;
63 struct meson_uart *const uart = plat->reg;
64
65 meson_serial_init(uart);
66
67 return 0;
68}
69
70static int meson_serial_getc(struct udevice *dev)
71{
72 struct meson_serial_platdata *plat = dev->platdata;
73 struct meson_uart *const uart = plat->reg;
74
75 if (readl(&uart->status) & AML_UART_RX_EMPTY)
76 return -EAGAIN;
77
78 return readl(&uart->rfifo) & 0xff;
79}
80
81static int meson_serial_putc(struct udevice *dev, const char ch)
82{
83 struct meson_serial_platdata *plat = dev->platdata;
84 struct meson_uart *const uart = plat->reg;
85
86 if (readl(&uart->status) & AML_UART_TX_FULL)
87 return -EAGAIN;
88
89 writel(ch, &uart->wfifo);
90
91 return 0;
92}
93
94static int meson_serial_pending(struct udevice *dev, bool input)
95{
96 struct meson_serial_platdata *plat = dev->platdata;
97 struct meson_uart *const uart = plat->reg;
98 uint32_t status = readl(&uart->status);
99
100 if (input)
101 return !(status & AML_UART_RX_EMPTY);
102 else
103 return !(status & AML_UART_TX_FULL);
104}
105
106static int meson_serial_ofdata_to_platdata(struct udevice *dev)
107{
108 struct meson_serial_platdata *plat = dev->platdata;
109 fdt_addr_t addr;
110
Simon Glassa821c4a2017-05-17 17:18:05 -0600111 addr = devfdt_get_addr(dev);
Beniamino Galvanibfcef282016-05-08 08:30:16 +0200112 if (addr == FDT_ADDR_T_NONE)
113 return -EINVAL;
114
115 plat->reg = (struct meson_uart *)addr;
116
117 return 0;
118}
119
120static const struct dm_serial_ops meson_serial_ops = {
121 .putc = meson_serial_putc,
122 .pending = meson_serial_pending,
123 .getc = meson_serial_getc,
124};
125
126static const struct udevice_id meson_serial_ids[] = {
127 { .compatible = "amlogic,meson-uart" },
128 { }
129};
130
131U_BOOT_DRIVER(serial_meson) = {
132 .name = "serial_meson",
133 .id = UCLASS_SERIAL,
134 .of_match = meson_serial_ids,
135 .probe = meson_serial_probe,
136 .ops = &meson_serial_ops,
137 .flags = DM_FLAG_PRE_RELOC,
138 .ofdata_to_platdata = meson_serial_ofdata_to_platdata,
139 .platdata_auto_alloc_size = sizeof(struct meson_serial_platdata),
140};
141
142#ifdef CONFIG_DEBUG_UART_MESON
143
144#include <debug_uart.h>
145
146static inline void _debug_uart_init(void)
147{
148}
149
150static inline void _debug_uart_putc(int ch)
151{
152 struct meson_uart *regs = (struct meson_uart *)CONFIG_DEBUG_UART_BASE;
153
154 while (readl(&regs->status) & AML_UART_TX_FULL)
155 ;
156
157 writel(ch, &regs->wfifo);
158}
159
160DEBUG_UART_FUNCS
161
162#endif