1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2008 - 2015 Michal Simek <monstr@monstr.eu>
4  * Clean driver and add xilinx constant from header file
5  *
6  * (C) Copyright 2004 Atmark Techno, Inc.
7  * Yasushi SHOJI <yashi@atmark-techno.com>
8  */
9 
10 #include <config.h>
11 #include <common.h>
12 #include <dm.h>
13 #include <asm/io.h>
14 #include <linux/compiler.h>
15 #include <serial.h>
16 
17 #define SR_TX_FIFO_FULL		BIT(3) /* transmit FIFO full */
18 #define SR_TX_FIFO_EMPTY	BIT(2) /* transmit FIFO empty */
19 #define SR_RX_FIFO_VALID_DATA	BIT(0) /* data in receive FIFO */
20 #define SR_RX_FIFO_FULL		BIT(1) /* receive FIFO full */
21 
22 #define ULITE_CONTROL_RST_TX	0x01
23 #define ULITE_CONTROL_RST_RX	0x02
24 
25 struct uartlite {
26 	unsigned int rx_fifo;
27 	unsigned int tx_fifo;
28 	unsigned int status;
29 	unsigned int control;
30 };
31 
32 struct uartlite_platdata {
33 	struct uartlite *regs;
34 };
35 
36 static int uartlite_serial_putc(struct udevice *dev, const char ch)
37 {
38 	struct uartlite_platdata *plat = dev_get_platdata(dev);
39 	struct uartlite *regs = plat->regs;
40 
41 	if (in_be32(&regs->status) & SR_TX_FIFO_FULL)
42 		return -EAGAIN;
43 
44 	out_be32(&regs->tx_fifo, ch & 0xff);
45 
46 	return 0;
47 }
48 
49 static int uartlite_serial_getc(struct udevice *dev)
50 {
51 	struct uartlite_platdata *plat = dev_get_platdata(dev);
52 	struct uartlite *regs = plat->regs;
53 
54 	if (!(in_be32(&regs->status) & SR_RX_FIFO_VALID_DATA))
55 		return -EAGAIN;
56 
57 	return in_be32(&regs->rx_fifo) & 0xff;
58 }
59 
60 static int uartlite_serial_pending(struct udevice *dev, bool input)
61 {
62 	struct uartlite_platdata *plat = dev_get_platdata(dev);
63 	struct uartlite *regs = plat->regs;
64 
65 	if (input)
66 		return in_be32(&regs->status) & SR_RX_FIFO_VALID_DATA;
67 
68 	return !(in_be32(&regs->status) & SR_TX_FIFO_EMPTY);
69 }
70 
71 static int uartlite_serial_probe(struct udevice *dev)
72 {
73 	struct uartlite_platdata *plat = dev_get_platdata(dev);
74 	struct uartlite *regs = plat->regs;
75 
76 	out_be32(&regs->control, 0);
77 	out_be32(&regs->control, ULITE_CONTROL_RST_RX | ULITE_CONTROL_RST_TX);
78 	in_be32(&regs->control);
79 
80 	return 0;
81 }
82 
83 static int uartlite_serial_ofdata_to_platdata(struct udevice *dev)
84 {
85 	struct uartlite_platdata *plat = dev_get_platdata(dev);
86 
87 	plat->regs = (struct uartlite *)devfdt_get_addr(dev);
88 
89 	return 0;
90 }
91 
92 static const struct dm_serial_ops uartlite_serial_ops = {
93 	.putc = uartlite_serial_putc,
94 	.pending = uartlite_serial_pending,
95 	.getc = uartlite_serial_getc,
96 };
97 
98 static const struct udevice_id uartlite_serial_ids[] = {
99 	{ .compatible = "xlnx,opb-uartlite-1.00.b", },
100 	{ .compatible = "xlnx,xps-uartlite-1.00.a" },
101 	{ }
102 };
103 
104 U_BOOT_DRIVER(serial_uartlite) = {
105 	.name	= "serial_uartlite",
106 	.id	= UCLASS_SERIAL,
107 	.of_match = uartlite_serial_ids,
108 	.ofdata_to_platdata = uartlite_serial_ofdata_to_platdata,
109 	.platdata_auto_alloc_size = sizeof(struct uartlite_platdata),
110 	.probe = uartlite_serial_probe,
111 	.ops	= &uartlite_serial_ops,
112 };
113 
114 #ifdef CONFIG_DEBUG_UART_UARTLITE
115 
116 #include <debug_uart.h>
117 
118 static inline void _debug_uart_init(void)
119 {
120 	struct uartlite *regs = (struct uartlite *)CONFIG_DEBUG_UART_BASE;
121 
122 	out_be32(&regs->control, 0);
123 	out_be32(&regs->control, ULITE_CONTROL_RST_RX | ULITE_CONTROL_RST_TX);
124 	in_be32(&regs->control);
125 }
126 
127 static inline void _debug_uart_putc(int ch)
128 {
129 	struct uartlite *regs = (struct uartlite *)CONFIG_DEBUG_UART_BASE;
130 
131 	while (in_be32(&regs->status) & SR_TX_FIFO_FULL)
132 		;
133 
134 	out_be32(&regs->tx_fifo, ch & 0xff);
135 }
136 
137 DEBUG_UART_FUNCS
138 #endif
139