1 /*
2  * Copyright (C) 2012-2014 Panasonic Corporation
3  *   Author: Masahiro Yamada <yamada.m@jp.panasonic.com>
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <asm/io.h>
10 #include <asm/errno.h>
11 #include <dm/device.h>
12 #include <dm/platform_data/serial-uniphier.h>
13 #include <serial.h>
14 
15 #define UART_REG(x)					\
16 	u8 x;						\
17 	u8 postpad_##x[3];
18 
19 /*
20  * Note: Register map is slightly different from that of 16550.
21  */
22 struct uniphier_serial {
23 	UART_REG(rbr);		/* 0x00 */
24 	UART_REG(ier);		/* 0x04 */
25 	UART_REG(iir);		/* 0x08 */
26 	UART_REG(fcr);		/* 0x0c */
27 	u8 mcr;			/* 0x10 */
28 	u8 lcr;
29 	u16 __postpad;
30 	UART_REG(lsr);		/* 0x14 */
31 	UART_REG(msr);		/* 0x18 */
32 	u32 __none1;
33 	u32 __none2;
34 	u16 dlr;
35 	u16 __postpad2;
36 };
37 
38 #define thr rbr
39 
40 /*
41  * These are the definitions for the Line Control Register
42  */
43 #define UART_LCR_WLS_8	0x03		/* 8 bit character length */
44 
45 /*
46  * These are the definitions for the Line Status Register
47  */
48 #define UART_LSR_DR	0x01		/* Data ready */
49 #define UART_LSR_THRE	0x20		/* Xmit holding register empty */
50 
51 struct uniphier_serial_private_data {
52 	struct uniphier_serial __iomem *membase;
53 };
54 
55 #define uniphier_serial_port(dev)	\
56 	((struct uniphier_serial_private_data *)dev_get_priv(dev))->membase
57 
58 static int uniphier_serial_setbrg(struct udevice *dev, int baudrate)
59 {
60 	struct uniphier_serial_platform_data *plat = dev_get_platdata(dev);
61 	struct uniphier_serial __iomem *port = uniphier_serial_port(dev);
62 	const unsigned int mode_x_div = 16;
63 	unsigned int divisor;
64 
65 	writeb(UART_LCR_WLS_8, &port->lcr);
66 
67 	divisor = DIV_ROUND_CLOSEST(plat->uartclk, mode_x_div * baudrate);
68 
69 	writew(divisor, &port->dlr);
70 
71 	return 0;
72 }
73 
74 static int uniphier_serial_getc(struct udevice *dev)
75 {
76 	struct uniphier_serial __iomem *port = uniphier_serial_port(dev);
77 
78 	if (!(readb(&port->lsr) & UART_LSR_DR))
79 		return -EAGAIN;
80 
81 	return readb(&port->rbr);
82 }
83 
84 static int uniphier_serial_putc(struct udevice *dev, const char c)
85 {
86 	struct uniphier_serial __iomem *port = uniphier_serial_port(dev);
87 
88 	if (!(readb(&port->lsr) & UART_LSR_THRE))
89 		return -EAGAIN;
90 
91 	writeb(c, &port->thr);
92 
93 	return 0;
94 }
95 
96 static int uniphier_serial_pending(struct udevice *dev, bool input)
97 {
98 	struct uniphier_serial __iomem *port = uniphier_serial_port(dev);
99 
100 	if (input)
101 		return readb(&port->lsr) & UART_LSR_DR;
102 	else
103 		return !(readb(&port->lsr) & UART_LSR_THRE);
104 }
105 
106 static int uniphier_serial_probe(struct udevice *dev)
107 {
108 	struct uniphier_serial_private_data *priv = dev_get_priv(dev);
109 	struct uniphier_serial_platform_data *plat = dev_get_platdata(dev);
110 
111 	priv->membase = map_sysmem(plat->base, sizeof(struct uniphier_serial));
112 
113 	if (!priv->membase)
114 		return -ENOMEM;
115 
116 	return 0;
117 }
118 
119 static int uniphier_serial_remove(struct udevice *dev)
120 {
121 	unmap_sysmem(uniphier_serial_port(dev));
122 
123 	return 0;
124 }
125 
126 #ifdef CONFIG_OF_CONTROL
127 static const struct udevice_id uniphier_uart_of_match = {
128 	{ .compatible = "panasonic,uniphier-uart"},
129 	{},
130 };
131 
132 static int uniphier_serial_ofdata_to_platdata(struct udevice *dev)
133 {
134 	/*
135 	 * TODO: Masahiro Yamada (yamada.m@jp.panasonic.com)
136 	 *
137 	 * Implement conversion code from DTB to platform data
138 	 * when supporting CONFIG_OF_CONTROL on UniPhir platform.
139 	 */
140 }
141 #endif
142 
143 static const struct dm_serial_ops uniphier_serial_ops = {
144 	.setbrg = uniphier_serial_setbrg,
145 	.getc = uniphier_serial_getc,
146 	.putc = uniphier_serial_putc,
147 	.pending = uniphier_serial_pending,
148 };
149 
150 U_BOOT_DRIVER(uniphier_serial) = {
151 	.name = DRIVER_NAME,
152 	.id = UCLASS_SERIAL,
153 	.of_match = of_match_ptr(uniphier_uart_of_match),
154 	.ofdata_to_platdata = of_match_ptr(uniphier_serial_ofdata_to_platdata),
155 	.probe = uniphier_serial_probe,
156 	.remove = uniphier_serial_remove,
157 	.priv_auto_alloc_size = sizeof(struct uniphier_serial_private_data),
158 	.platdata_auto_alloc_size =
159 				sizeof(struct uniphier_serial_platform_data),
160 	.ops = &uniphier_serial_ops,
161 	.flags = DM_FLAG_PRE_RELOC,
162 };
163