2 * (C) Copyright 2016 Beniamino Galvani <b.galvani@gmail.com>
4 * SPDX-License-Identifier: GPL-2.0+
11 #include <linux/compiler.h>
14 DECLARE_GLOBAL_DATA_PTR
;
24 struct meson_serial_platdata
{
25 struct meson_uart
*reg
;
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)
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)
47 static void meson_serial_init(struct meson_uart
*uart
)
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
);
60 static int meson_serial_probe(struct udevice
*dev
)
62 struct meson_serial_platdata
*plat
= dev
->platdata
;
63 struct meson_uart
*const uart
= plat
->reg
;
65 meson_serial_init(uart
);
70 static int meson_serial_getc(struct udevice
*dev
)
72 struct meson_serial_platdata
*plat
= dev
->platdata
;
73 struct meson_uart
*const uart
= plat
->reg
;
75 if (readl(&uart
->status
) & AML_UART_RX_EMPTY
)
78 return readl(&uart
->rfifo
) & 0xff;
81 static int meson_serial_putc(struct udevice
*dev
, const char ch
)
83 struct meson_serial_platdata
*plat
= dev
->platdata
;
84 struct meson_uart
*const uart
= plat
->reg
;
86 if (readl(&uart
->status
) & AML_UART_TX_FULL
)
89 writel(ch
, &uart
->wfifo
);
94 static int meson_serial_pending(struct udevice
*dev
, bool input
)
96 struct meson_serial_platdata
*plat
= dev
->platdata
;
97 struct meson_uart
*const uart
= plat
->reg
;
98 uint32_t status
= readl(&uart
->status
);
101 return !(status
& AML_UART_RX_EMPTY
);
103 return !(status
& AML_UART_TX_FULL
);
106 static int meson_serial_ofdata_to_platdata(struct udevice
*dev
)
108 struct meson_serial_platdata
*plat
= dev
->platdata
;
111 addr
= devfdt_get_addr(dev
);
112 if (addr
== FDT_ADDR_T_NONE
)
115 plat
->reg
= (struct meson_uart
*)addr
;
120 static const struct dm_serial_ops meson_serial_ops
= {
121 .putc
= meson_serial_putc
,
122 .pending
= meson_serial_pending
,
123 .getc
= meson_serial_getc
,
126 static const struct udevice_id meson_serial_ids
[] = {
127 { .compatible
= "amlogic,meson-uart" },
131 U_BOOT_DRIVER(serial_meson
) = {
132 .name
= "serial_meson",
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
),
142 #ifdef CONFIG_DEBUG_UART_MESON
144 #include <debug_uart.h>
146 static inline void _debug_uart_init(void)
150 static inline void _debug_uart_putc(int ch
)
152 struct meson_uart
*regs
= (struct meson_uart
*)CONFIG_DEBUG_UART_BASE
;
154 while (readl(®s
->status
) & AML_UART_TX_FULL
)
157 writel(ch
, ®s
->wfifo
);