1 /*
2  * (C) Copyright 2008 - 2015 Michal Simek <monstr@monstr.eu>
3  * Clean driver and add xilinx constant from header file
4  *
5  * (C) Copyright 2004 Atmark Techno, Inc.
6  * Yasushi SHOJI <yashi@atmark-techno.com>
7  *
8  * SPDX-License-Identifier:	GPL-2.0+
9  */
10 
11 #include <config.h>
12 #include <common.h>
13 #include <dm.h>
14 #include <asm/io.h>
15 #include <linux/compiler.h>
16 #include <serial.h>
17 
18 DECLARE_GLOBAL_DATA_PTR;
19 
20 #define SR_TX_FIFO_FULL		BIT(3) /* transmit FIFO full */
21 #define SR_TX_FIFO_EMPTY	BIT(2) /* transmit FIFO empty */
22 #define SR_RX_FIFO_VALID_DATA	BIT(0) /* data in receive FIFO */
23 #define SR_RX_FIFO_FULL		BIT(1) /* receive FIFO full */
24 
25 #define ULITE_CONTROL_RST_TX	0x01
26 #define ULITE_CONTROL_RST_RX	0x02
27 
28 struct uartlite {
29 	unsigned int rx_fifo;
30 	unsigned int tx_fifo;
31 	unsigned int status;
32 	unsigned int control;
33 };
34 
35 struct uartlite_platdata {
36 	struct uartlite *regs;
37 };
38 
39 static int uartlite_serial_putc(struct udevice *dev, const char ch)
40 {
41 	struct uartlite_platdata *plat = dev_get_platdata(dev);
42 	struct uartlite *regs = plat->regs;
43 
44 	if (in_be32(&regs->status) & SR_TX_FIFO_FULL)
45 		return -EAGAIN;
46 
47 	out_be32(&regs->tx_fifo, ch & 0xff);
48 
49 	return 0;
50 }
51 
52 static int uartlite_serial_getc(struct udevice *dev)
53 {
54 	struct uartlite_platdata *plat = dev_get_platdata(dev);
55 	struct uartlite *regs = plat->regs;
56 
57 	if (!(in_be32(&regs->status) & SR_RX_FIFO_VALID_DATA))
58 		return -EAGAIN;
59 
60 	return in_be32(&regs->rx_fifo) & 0xff;
61 }
62 
63 static int uartlite_serial_pending(struct udevice *dev, bool input)
64 {
65 	struct uartlite_platdata *plat = dev_get_platdata(dev);
66 	struct uartlite *regs = plat->regs;
67 
68 	if (input)
69 		return in_be32(&regs->status) & SR_RX_FIFO_VALID_DATA;
70 
71 	return !(in_be32(&regs->status) & SR_TX_FIFO_EMPTY);
72 }
73 
74 static int uartlite_serial_probe(struct udevice *dev)
75 {
76 	struct uartlite_platdata *plat = dev_get_platdata(dev);
77 	struct uartlite *regs = plat->regs;
78 
79 	out_be32(&regs->control, 0);
80 	out_be32(&regs->control, ULITE_CONTROL_RST_RX | ULITE_CONTROL_RST_TX);
81 	in_be32(&regs->control);
82 
83 	return 0;
84 }
85 
86 static int uartlite_serial_ofdata_to_platdata(struct udevice *dev)
87 {
88 	struct uartlite_platdata *plat = dev_get_platdata(dev);
89 
90 	plat->regs = (struct uartlite *)devfdt_get_addr(dev);
91 
92 	return 0;
93 }
94 
95 static const struct dm_serial_ops uartlite_serial_ops = {
96 	.putc = uartlite_serial_putc,
97 	.pending = uartlite_serial_pending,
98 	.getc = uartlite_serial_getc,
99 };
100 
101 static const struct udevice_id uartlite_serial_ids[] = {
102 	{ .compatible = "xlnx,opb-uartlite-1.00.b", },
103 	{ .compatible = "xlnx,xps-uartlite-1.00.a" },
104 	{ }
105 };
106 
107 U_BOOT_DRIVER(serial_uartlite) = {
108 	.name	= "serial_uartlite",
109 	.id	= UCLASS_SERIAL,
110 	.of_match = uartlite_serial_ids,
111 	.ofdata_to_platdata = uartlite_serial_ofdata_to_platdata,
112 	.platdata_auto_alloc_size = sizeof(struct uartlite_platdata),
113 	.probe = uartlite_serial_probe,
114 	.ops	= &uartlite_serial_ops,
115 	.flags = DM_FLAG_PRE_RELOC,
116 };
117 
118 #ifdef CONFIG_DEBUG_UART_UARTLITE
119 
120 #include <debug_uart.h>
121 
122 static inline void _debug_uart_init(void)
123 {
124 	struct uartlite *regs = (struct uartlite *)CONFIG_DEBUG_UART_BASE;
125 
126 	out_be32(&regs->control, 0);
127 	out_be32(&regs->control, ULITE_CONTROL_RST_RX | ULITE_CONTROL_RST_TX);
128 	in_be32(&regs->control);
129 }
130 
131 static inline void _debug_uart_putc(int ch)
132 {
133 	struct uartlite *regs = (struct uartlite *)CONFIG_DEBUG_UART_BASE;
134 
135 	while (in_be32(&regs->status) & SR_TX_FIFO_FULL)
136 		;
137 
138 	out_be32(&regs->tx_fifo, ch & 0xff);
139 }
140 
141 DEBUG_UART_FUNCS
142 #endif
143