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Tom Rini83d290c2018-05-06 17:58:06 -04001// SPDX-License-Identifier: GPL-2.0+
Beniamino Galvanibfcef282016-05-08 08:30:16 +02002/*
3 * (C) Copyright 2016 Beniamino Galvani <b.galvani@gmail.com>
Beniamino Galvanibfcef282016-05-08 08:30:16 +02004 */
5
6#include <common.h>
7#include <dm.h>
8#include <errno.h>
9#include <fdtdec.h>
10#include <linux/compiler.h>
11#include <serial.h>
12
Beniamino Galvanibfcef282016-05-08 08:30:16 +020013struct meson_uart {
14 u32 wfifo;
15 u32 rfifo;
16 u32 control;
17 u32 status;
18 u32 misc;
19};
20
21struct meson_serial_platdata {
22 struct meson_uart *reg;
23};
24
25/* AML_UART_STATUS bits */
26#define AML_UART_PARITY_ERR BIT(16)
27#define AML_UART_FRAME_ERR BIT(17)
28#define AML_UART_TX_FIFO_WERR BIT(18)
29#define AML_UART_RX_EMPTY BIT(20)
30#define AML_UART_TX_FULL BIT(21)
31#define AML_UART_TX_EMPTY BIT(22)
32#define AML_UART_XMIT_BUSY BIT(25)
33#define AML_UART_ERR (AML_UART_PARITY_ERR | \
34 AML_UART_FRAME_ERR | \
35 AML_UART_TX_FIFO_WERR)
36
37/* AML_UART_CONTROL bits */
38#define AML_UART_TX_EN BIT(12)
39#define AML_UART_RX_EN BIT(13)
40#define AML_UART_TX_RST BIT(22)
41#define AML_UART_RX_RST BIT(23)
42#define AML_UART_CLR_ERR BIT(24)
43
44static void meson_serial_init(struct meson_uart *uart)
45{
46 u32 val;
47
48 val = readl(&uart->control);
49 val |= (AML_UART_RX_RST | AML_UART_TX_RST | AML_UART_CLR_ERR);
50 writel(val, &uart->control);
51 val &= ~(AML_UART_RX_RST | AML_UART_TX_RST | AML_UART_CLR_ERR);
52 writel(val, &uart->control);
53 val |= (AML_UART_RX_EN | AML_UART_TX_EN);
54 writel(val, &uart->control);
55}
56
57static int meson_serial_probe(struct udevice *dev)
58{
59 struct meson_serial_platdata *plat = dev->platdata;
60 struct meson_uart *const uart = plat->reg;
61
62 meson_serial_init(uart);
63
64 return 0;
65}
66
67static int meson_serial_getc(struct udevice *dev)
68{
69 struct meson_serial_platdata *plat = dev->platdata;
70 struct meson_uart *const uart = plat->reg;
71
72 if (readl(&uart->status) & AML_UART_RX_EMPTY)
73 return -EAGAIN;
74
75 return readl(&uart->rfifo) & 0xff;
76}
77
78static int meson_serial_putc(struct udevice *dev, const char ch)
79{
80 struct meson_serial_platdata *plat = dev->platdata;
81 struct meson_uart *const uart = plat->reg;
82
83 if (readl(&uart->status) & AML_UART_TX_FULL)
84 return -EAGAIN;
85
86 writel(ch, &uart->wfifo);
87
88 return 0;
89}
90
91static int meson_serial_pending(struct udevice *dev, bool input)
92{
93 struct meson_serial_platdata *plat = dev->platdata;
94 struct meson_uart *const uart = plat->reg;
95 uint32_t status = readl(&uart->status);
96
97 if (input)
98 return !(status & AML_UART_RX_EMPTY);
99 else
100 return !(status & AML_UART_TX_FULL);
101}
102
103static int meson_serial_ofdata_to_platdata(struct udevice *dev)
104{
105 struct meson_serial_platdata *plat = dev->platdata;
106 fdt_addr_t addr;
107
Simon Glassa821c4a2017-05-17 17:18:05 -0600108 addr = devfdt_get_addr(dev);
Beniamino Galvanibfcef282016-05-08 08:30:16 +0200109 if (addr == FDT_ADDR_T_NONE)
110 return -EINVAL;
111
112 plat->reg = (struct meson_uart *)addr;
113
114 return 0;
115}
116
117static const struct dm_serial_ops meson_serial_ops = {
118 .putc = meson_serial_putc,
119 .pending = meson_serial_pending,
120 .getc = meson_serial_getc,
121};
122
123static const struct udevice_id meson_serial_ids[] = {
124 { .compatible = "amlogic,meson-uart" },
Neil Armstronge1e1e852018-03-29 14:56:02 +0200125 { .compatible = "amlogic,meson-gx-uart" },
Beniamino Galvanibfcef282016-05-08 08:30:16 +0200126 { }
127};
128
129U_BOOT_DRIVER(serial_meson) = {
130 .name = "serial_meson",
131 .id = UCLASS_SERIAL,
132 .of_match = meson_serial_ids,
133 .probe = meson_serial_probe,
134 .ops = &meson_serial_ops,
135 .flags = DM_FLAG_PRE_RELOC,
136 .ofdata_to_platdata = meson_serial_ofdata_to_platdata,
137 .platdata_auto_alloc_size = sizeof(struct meson_serial_platdata),
138};
139
140#ifdef CONFIG_DEBUG_UART_MESON
141
142#include <debug_uart.h>
143
144static inline void _debug_uart_init(void)
145{
146}
147
148static inline void _debug_uart_putc(int ch)
149{
150 struct meson_uart *regs = (struct meson_uart *)CONFIG_DEBUG_UART_BASE;
151
152 while (readl(&regs->status) & AML_UART_TX_FULL)
153 ;
154
155 writel(ch, &regs->wfifo);
156}
157
158DEBUG_UART_FUNCS
159
160#endif