1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
|
/*
* Renesas Emma Mobile 8250 driver
*
* Copyright (C) 2012 Magnus Damm
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/device.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/serial_8250.h>
#include <linux/serial_core.h>
#include <linux/serial_reg.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/slab.h>
#include "8250.h"
#define UART_DLL_EM 9
#define UART_DLM_EM 10
struct serial8250_em_priv {
struct clk *sclk;
int line;
};
static void serial8250_em_serial_out(struct uart_port *p, int offset, int value)
{
switch (offset) {
case UART_TX: /* TX @ 0x00 */
writeb(value, p->membase);
break;
case UART_FCR: /* FCR @ 0x0c (+1) */
case UART_LCR: /* LCR @ 0x10 (+1) */
case UART_MCR: /* MCR @ 0x14 (+1) */
case UART_SCR: /* SCR @ 0x20 (+1) */
writel(value, p->membase + ((offset + 1) << 2));
break;
case UART_IER: /* IER @ 0x04 */
value &= 0x0f; /* only 4 valid bits - not Xscale */
/* fall-through */
case UART_DLL_EM: /* DLL @ 0x24 (+9) */
case UART_DLM_EM: /* DLM @ 0x28 (+9) */
writel(value, p->membase + (offset << 2));
}
}
static unsigned int serial8250_em_serial_in(struct uart_port *p, int offset)
{
switch (offset) {
case UART_RX: /* RX @ 0x00 */
return readb(p->membase);
case UART_MCR: /* MCR @ 0x14 (+1) */
case UART_LSR: /* LSR @ 0x18 (+1) */
case UART_MSR: /* MSR @ 0x1c (+1) */
case UART_SCR: /* SCR @ 0x20 (+1) */
return readl(p->membase + ((offset + 1) << 2));
case UART_IER: /* IER @ 0x04 */
case UART_IIR: /* IIR @ 0x08 */
case UART_DLL_EM: /* DLL @ 0x24 (+9) */
case UART_DLM_EM: /* DLM @ 0x28 (+9) */
return readl(p->membase + (offset << 2));
}
return 0;
}
static int serial8250_em_serial_dl_read(struct uart_8250_port *up)
{
return serial_in(up, UART_DLL_EM) | serial_in(up, UART_DLM_EM) << 8;
}
static void serial8250_em_serial_dl_write(struct uart_8250_port *up, int value)
{
serial_out(up, UART_DLL_EM, value & 0xff);
serial_out(up, UART_DLM_EM, value >> 8 & 0xff);
}
static int serial8250_em_probe(struct platform_device *pdev)
{
struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
struct serial8250_em_priv *priv;
struct uart_8250_port up;
int ret;
if (!regs || !irq) {
dev_err(&pdev->dev, "missing registers or irq\n");
return -EINVAL;
}
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv) {
dev_err(&pdev->dev, "unable to allocate private data\n");
return -ENOMEM;
}
priv->sclk = devm_clk_get(&pdev->dev, "sclk");
if (IS_ERR(priv->sclk)) {
dev_err(&pdev->dev, "unable to get clock\n");
return PTR_ERR(priv->sclk);
}
memset(&up, 0, sizeof(up));
up.port.mapbase = regs->start;
up.port.irq = irq->start;
up.port.type = PORT_UNKNOWN;
up.port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP;
up.port.dev = &pdev->dev;
up.port.private_data = priv;
clk_prepare_enable(priv->sclk);
up.port.uartclk = clk_get_rate(priv->sclk);
up.port.iotype = UPIO_MEM32;
up.port.serial_in = serial8250_em_serial_in;
up.port.serial_out = serial8250_em_serial_out;
up.dl_read = serial8250_em_serial_dl_read;
up.dl_write = serial8250_em_serial_dl_write;
ret = serial8250_register_8250_port(&up);
if (ret < 0) {
dev_err(&pdev->dev, "unable to register 8250 port\n");
clk_disable_unprepare(priv->sclk);
return ret;
}
priv->line = ret;
platform_set_drvdata(pdev, priv);
return 0;
}
static int serial8250_em_remove(struct platform_device *pdev)
{
struct serial8250_em_priv *priv = platform_get_drvdata(pdev);
serial8250_unregister_port(priv->line);
clk_disable_unprepare(priv->sclk);
return 0;
}
static const struct of_device_id serial8250_em_dt_ids[] = {
{ .compatible = "renesas,em-uart", },
{},
};
MODULE_DEVICE_TABLE(of, serial8250_em_dt_ids);
static struct platform_driver serial8250_em_platform_driver = {
.driver = {
.name = "serial8250-em",
.of_match_table = serial8250_em_dt_ids,
.owner = THIS_MODULE,
},
.probe = serial8250_em_probe,
.remove = serial8250_em_remove,
};
module_platform_driver(serial8250_em_platform_driver);
MODULE_AUTHOR("Magnus Damm");
MODULE_DESCRIPTION("Renesas Emma Mobile 8250 Driver");
MODULE_LICENSE("GPL v2");
|
