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5
6#include <common.h>
7#include <dm.h>
8#include <errno.h>
9#include <fdtdec.h>
10#include <linux/bitops.h>
11#include <linux/compiler.h>
12#include <serial.h>
13
14struct meson_uart {
15 u32 wfifo;
16 u32 rfifo;
17 u32 control;
18 u32 status;
19 u32 misc;
20};
21
22struct meson_serial_plat {
23 struct meson_uart *reg;
24};
25
26
27#define AML_UART_PARITY_ERR BIT(16)
28#define AML_UART_FRAME_ERR BIT(17)
29#define AML_UART_TX_FIFO_WERR BIT(18)
30#define AML_UART_RX_EMPTY BIT(20)
31#define AML_UART_TX_FULL BIT(21)
32#define AML_UART_TX_EMPTY BIT(22)
33#define AML_UART_XMIT_BUSY BIT(25)
34#define AML_UART_ERR (AML_UART_PARITY_ERR | \
35 AML_UART_FRAME_ERR | \
36 AML_UART_TX_FIFO_WERR)
37
38
39#define AML_UART_TX_EN BIT(12)
40#define AML_UART_RX_EN BIT(13)
41#define AML_UART_TX_RST BIT(22)
42#define AML_UART_RX_RST BIT(23)
43#define AML_UART_CLR_ERR BIT(24)
44
45static void meson_serial_init(struct meson_uart *uart)
46{
47 u32 val;
48
49 val = readl(&uart->control);
50 val |= (AML_UART_RX_RST | AML_UART_TX_RST | AML_UART_CLR_ERR);
51 writel(val, &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_EN | AML_UART_TX_EN);
55 writel(val, &uart->control);
56}
57
58static int meson_serial_probe(struct udevice *dev)
59{
60 struct meson_serial_plat *plat = dev_get_plat(dev);
61 struct meson_uart *const uart = plat->reg;
62
63 meson_serial_init(uart);
64
65 return 0;
66}
67
68static void meson_serial_rx_error(struct udevice *dev)
69{
70 struct meson_serial_plat *plat = dev_get_plat(dev);
71 struct meson_uart *const uart = plat->reg;
72 u32 val = readl(&uart->control);
73
74
75 val |= AML_UART_CLR_ERR;
76 writel(val, &uart->control);
77 val &= ~AML_UART_CLR_ERR;
78 writel(val, &uart->control);
79
80
81 readl(&uart->rfifo);
82}
83
84static int meson_serial_getc(struct udevice *dev)
85{
86 struct meson_serial_plat *plat = dev_get_plat(dev);
87 struct meson_uart *const uart = plat->reg;
88 uint32_t status = readl(&uart->status);
89
90 if (status & AML_UART_RX_EMPTY)
91 return -EAGAIN;
92
93 if (status & AML_UART_ERR) {
94 meson_serial_rx_error(dev);
95 return -EIO;
96 }
97
98 return readl(&uart->rfifo) & 0xff;
99}
100
101static int meson_serial_putc(struct udevice *dev, const char ch)
102{
103 struct meson_serial_plat *plat = dev_get_plat(dev);
104 struct meson_uart *const uart = plat->reg;
105
106 if (readl(&uart->status) & AML_UART_TX_FULL)
107 return -EAGAIN;
108
109 writel(ch, &uart->wfifo);
110
111 return 0;
112}
113
114static int meson_serial_pending(struct udevice *dev, bool input)
115{
116 struct meson_serial_plat *plat = dev_get_plat(dev);
117 struct meson_uart *const uart = plat->reg;
118 uint32_t status = readl(&uart->status);
119
120 if (input) {
121 if (status & AML_UART_RX_EMPTY)
122 return false;
123
124
125
126
127
128 if (status & AML_UART_ERR) {
129 meson_serial_rx_error(dev);
130 return false;
131 }
132
133 return true;
134 } else {
135 return !(status & AML_UART_TX_FULL);
136 }
137}
138
139static int meson_serial_of_to_plat(struct udevice *dev)
140{
141 struct meson_serial_plat *plat = dev_get_plat(dev);
142 fdt_addr_t addr;
143
144 addr = dev_read_addr(dev);
145 if (addr == FDT_ADDR_T_NONE)
146 return -EINVAL;
147
148 plat->reg = (struct meson_uart *)addr;
149
150 return 0;
151}
152
153static const struct dm_serial_ops meson_serial_ops = {
154 .putc = meson_serial_putc,
155 .pending = meson_serial_pending,
156 .getc = meson_serial_getc,
157};
158
159static const struct udevice_id meson_serial_ids[] = {
160 { .compatible = "amlogic,meson-uart" },
161 { .compatible = "amlogic,meson-gx-uart" },
162 { }
163};
164
165U_BOOT_DRIVER(serial_meson) = {
166 .name = "serial_meson",
167 .id = UCLASS_SERIAL,
168 .of_match = meson_serial_ids,
169 .probe = meson_serial_probe,
170 .ops = &meson_serial_ops,
171 .of_to_plat = meson_serial_of_to_plat,
172 .plat_auto = sizeof(struct meson_serial_plat),
173};
174
175#ifdef CONFIG_DEBUG_UART_MESON
176
177#include <debug_uart.h>
178
179static inline void _debug_uart_init(void)
180{
181}
182
183static inline void _debug_uart_putc(int ch)
184{
185 struct meson_uart *regs = (struct meson_uart *)CONFIG_DEBUG_UART_BASE;
186
187 while (readl(®s->status) & AML_UART_TX_FULL)
188 ;
189
190 writel(ch, ®s->wfifo);
191}
192
193DEBUG_UART_FUNCS
194
195#endif
196