serial8250-em: Add DT support
[linux-2.6/btrfs-unstable.git] / drivers / tty / serial / 8250 / 8250_em.c
blob3a0363e7f3a7455d0b30ce436c55c4bc77f5652d
1 /*
2 * Renesas Emma Mobile 8250 driver
4 * Copyright (C) 2012 Magnus Damm
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 #include <linux/device.h>
21 #include <linux/init.h>
22 #include <linux/io.h>
23 #include <linux/module.h>
24 #include <linux/serial_8250.h>
25 #include <linux/serial_core.h>
26 #include <linux/serial_reg.h>
27 #include <linux/platform_device.h>
28 #include <linux/clk.h>
29 #include <linux/slab.h>
31 #include "8250.h"
33 #define UART_DLL_EM 9
34 #define UART_DLM_EM 10
36 struct serial8250_em_priv {
37 struct clk *sclk;
38 int line;
41 static void serial8250_em_serial_out(struct uart_port *p, int offset, int value)
43 switch (offset) {
44 case UART_TX: /* TX @ 0x00 */
45 writeb(value, p->membase);
46 break;
47 case UART_FCR: /* FCR @ 0x0c (+1) */
48 case UART_LCR: /* LCR @ 0x10 (+1) */
49 case UART_MCR: /* MCR @ 0x14 (+1) */
50 case UART_SCR: /* SCR @ 0x20 (+1) */
51 writel(value, p->membase + ((offset + 1) << 2));
52 break;
53 case UART_IER: /* IER @ 0x04 */
54 value &= 0x0f; /* only 4 valid bits - not Xscale */
55 /* fall-through */
56 case UART_DLL_EM: /* DLL @ 0x24 (+9) */
57 case UART_DLM_EM: /* DLM @ 0x28 (+9) */
58 writel(value, p->membase + (offset << 2));
62 static unsigned int serial8250_em_serial_in(struct uart_port *p, int offset)
64 switch (offset) {
65 case UART_RX: /* RX @ 0x00 */
66 return readb(p->membase);
67 case UART_MCR: /* MCR @ 0x14 (+1) */
68 case UART_LSR: /* LSR @ 0x18 (+1) */
69 case UART_MSR: /* MSR @ 0x1c (+1) */
70 case UART_SCR: /* SCR @ 0x20 (+1) */
71 return readl(p->membase + ((offset + 1) << 2));
72 case UART_IER: /* IER @ 0x04 */
73 case UART_IIR: /* IIR @ 0x08 */
74 case UART_DLL_EM: /* DLL @ 0x24 (+9) */
75 case UART_DLM_EM: /* DLM @ 0x28 (+9) */
76 return readl(p->membase + (offset << 2));
78 return 0;
81 static int serial8250_em_serial_dl_read(struct uart_8250_port *up)
83 return serial_in(up, UART_DLL_EM) | serial_in(up, UART_DLM_EM) << 8;
86 static void serial8250_em_serial_dl_write(struct uart_8250_port *up, int value)
88 serial_out(up, UART_DLL_EM, value & 0xff);
89 serial_out(up, UART_DLM_EM, value >> 8 & 0xff);
92 static int __devinit serial8250_em_probe(struct platform_device *pdev)
94 struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
95 struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
96 struct serial8250_em_priv *priv;
97 struct uart_8250_port up;
98 int ret = -EINVAL;
100 if (!regs || !irq) {
101 dev_err(&pdev->dev, "missing registers or irq\n");
102 goto err0;
105 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
106 if (!priv) {
107 dev_err(&pdev->dev, "unable to allocate private data\n");
108 ret = -ENOMEM;
109 goto err0;
112 priv->sclk = clk_get(&pdev->dev, "sclk");
113 if (IS_ERR(priv->sclk)) {
114 dev_err(&pdev->dev, "unable to get clock\n");
115 ret = PTR_ERR(priv->sclk);
116 goto err1;
119 memset(&up, 0, sizeof(up));
120 up.port.mapbase = regs->start;
121 up.port.irq = irq->start;
122 up.port.type = PORT_UNKNOWN;
123 up.port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP;
124 up.port.dev = &pdev->dev;
125 up.port.private_data = priv;
127 clk_enable(priv->sclk);
128 up.port.uartclk = clk_get_rate(priv->sclk);
130 up.port.iotype = UPIO_MEM32;
131 up.port.serial_in = serial8250_em_serial_in;
132 up.port.serial_out = serial8250_em_serial_out;
133 up.dl_read = serial8250_em_serial_dl_read;
134 up.dl_write = serial8250_em_serial_dl_write;
136 ret = serial8250_register_8250_port(&up);
137 if (ret < 0) {
138 dev_err(&pdev->dev, "unable to register 8250 port\n");
139 goto err2;
142 priv->line = ret;
143 platform_set_drvdata(pdev, priv);
144 return 0;
146 err2:
147 clk_disable(priv->sclk);
148 clk_put(priv->sclk);
149 err1:
150 kfree(priv);
151 err0:
152 return ret;
155 static int __devexit serial8250_em_remove(struct platform_device *pdev)
157 struct serial8250_em_priv *priv = platform_get_drvdata(pdev);
159 serial8250_unregister_port(priv->line);
160 clk_disable(priv->sclk);
161 clk_put(priv->sclk);
162 kfree(priv);
163 return 0;
166 static const struct of_device_id serial8250_em_dt_ids[] __devinitconst = {
167 { .compatible = "renesas,em-uart", },
170 MODULE_DEVICE_TABLE(of, serial8250_em_dt_ids);
172 static struct platform_driver serial8250_em_platform_driver = {
173 .driver = {
174 .name = "serial8250-em",
175 .of_match_table = serial8250_em_dt_ids,
176 .owner = THIS_MODULE,
178 .probe = serial8250_em_probe,
179 .remove = __devexit_p(serial8250_em_remove),
182 module_platform_driver(serial8250_em_platform_driver);
184 MODULE_AUTHOR("Magnus Damm");
185 MODULE_DESCRIPTION("Renesas Emma Mobile 8250 Driver");
186 MODULE_LICENSE("GPL v2");