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[linux-2.6-omap-h63xx.git] / drivers / serial / s3c2440.c
1 /* linux/drivers/serial/s3c2440.c
2  *
3  * Driver for Samsung S3C2440 and S3C2442 SoC onboard UARTs.
4  *
5  * Ben Dooks, Copyright (c) 2003-2005,2008 Simtec Electronics
6  *      http://armlinux.simtec.co.uk/
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11 */
12
13 #include <linux/module.h>
14 #include <linux/ioport.h>
15 #include <linux/io.h>
16 #include <linux/platform_device.h>
17 #include <linux/init.h>
18 #include <linux/serial_core.h>
19 #include <linux/serial.h>
20
21 #include <asm/irq.h>
22 #include <mach/hardware.h>
23
24 #include <plat/regs-serial.h>
25 #include <mach/regs-gpio.h>
26
27 #include "samsung.h"
28
29
30 static int s3c2440_serial_setsource(struct uart_port *port,
31                                      struct s3c24xx_uart_clksrc *clk)
32 {
33         unsigned long ucon = rd_regl(port, S3C2410_UCON);
34
35         /* todo - proper fclk<>nonfclk switch. */
36
37         ucon &= ~S3C2440_UCON_CLKMASK;
38
39         if (strcmp(clk->name, "uclk") == 0)
40                 ucon |= S3C2440_UCON_UCLK;
41         else if (strcmp(clk->name, "pclk") == 0)
42                 ucon |= S3C2440_UCON_PCLK;
43         else if (strcmp(clk->name, "fclk") == 0)
44                 ucon |= S3C2440_UCON_FCLK;
45         else {
46                 printk(KERN_ERR "unknown clock source %s\n", clk->name);
47                 return -EINVAL;
48         }
49
50         wr_regl(port, S3C2410_UCON, ucon);
51         return 0;
52 }
53
54
55 static int s3c2440_serial_getsource(struct uart_port *port,
56                                     struct s3c24xx_uart_clksrc *clk)
57 {
58         unsigned long ucon = rd_regl(port, S3C2410_UCON);
59         unsigned long ucon0, ucon1, ucon2;
60
61         switch (ucon & S3C2440_UCON_CLKMASK) {
62         case S3C2440_UCON_UCLK:
63                 clk->divisor = 1;
64                 clk->name = "uclk";
65                 break;
66
67         case S3C2440_UCON_PCLK:
68         case S3C2440_UCON_PCLK2:
69                 clk->divisor = 1;
70                 clk->name = "pclk";
71                 break;
72
73         case S3C2440_UCON_FCLK:
74                 /* the fun of calculating the uart divisors on
75                  * the s3c2440 */
76
77                 ucon0 = __raw_readl(S3C24XX_VA_UART0 + S3C2410_UCON);
78                 ucon1 = __raw_readl(S3C24XX_VA_UART1 + S3C2410_UCON);
79                 ucon2 = __raw_readl(S3C24XX_VA_UART2 + S3C2410_UCON);
80
81                 printk("ucons: %08lx, %08lx, %08lx\n", ucon0, ucon1, ucon2);
82
83                 ucon0 &= S3C2440_UCON0_DIVMASK;
84                 ucon1 &= S3C2440_UCON1_DIVMASK;
85                 ucon2 &= S3C2440_UCON2_DIVMASK;
86
87                 if (ucon0 != 0) {
88                         clk->divisor = ucon0 >> S3C2440_UCON_DIVSHIFT;
89                         clk->divisor += 6;
90                 } else if (ucon1 != 0) {
91                         clk->divisor = ucon1 >> S3C2440_UCON_DIVSHIFT;
92                         clk->divisor += 21;
93                 } else if (ucon2 != 0) {
94                         clk->divisor = ucon2 >> S3C2440_UCON_DIVSHIFT;
95                         clk->divisor += 36;
96                 } else {
97                         /* manual calims 44, seems to be 9 */
98                         clk->divisor = 9;
99                 }
100
101                 clk->name = "fclk";
102                 break;
103         }
104
105         return 0;
106 }
107
108 static int s3c2440_serial_resetport(struct uart_port *port,
109                                     struct s3c2410_uartcfg *cfg)
110 {
111         unsigned long ucon = rd_regl(port, S3C2410_UCON);
112
113         dbg("s3c2440_serial_resetport: port=%p (%08lx), cfg=%p\n",
114             port, port->mapbase, cfg);
115
116         /* ensure we don't change the clock settings... */
117
118         ucon &= (S3C2440_UCON0_DIVMASK | (3<<10));
119
120         wr_regl(port, S3C2410_UCON,  ucon | cfg->ucon);
121         wr_regl(port, S3C2410_ULCON, cfg->ulcon);
122
123         /* reset both fifos */
124
125         wr_regl(port, S3C2410_UFCON, cfg->ufcon | S3C2410_UFCON_RESETBOTH);
126         wr_regl(port, S3C2410_UFCON, cfg->ufcon);
127
128         return 0;
129 }
130
131 static struct s3c24xx_uart_info s3c2440_uart_inf = {
132         .name           = "Samsung S3C2440 UART",
133         .type           = PORT_S3C2440,
134         .fifosize       = 64,
135         .rx_fifomask    = S3C2440_UFSTAT_RXMASK,
136         .rx_fifoshift   = S3C2440_UFSTAT_RXSHIFT,
137         .rx_fifofull    = S3C2440_UFSTAT_RXFULL,
138         .tx_fifofull    = S3C2440_UFSTAT_TXFULL,
139         .tx_fifomask    = S3C2440_UFSTAT_TXMASK,
140         .tx_fifoshift   = S3C2440_UFSTAT_TXSHIFT,
141         .get_clksrc     = s3c2440_serial_getsource,
142         .set_clksrc     = s3c2440_serial_setsource,
143         .reset_port     = s3c2440_serial_resetport,
144 };
145
146 /* device management */
147
148 static int s3c2440_serial_probe(struct platform_device *dev)
149 {
150         dbg("s3c2440_serial_probe: dev=%p\n", dev);
151         return s3c24xx_serial_probe(dev, &s3c2440_uart_inf);
152 }
153
154 static struct platform_driver s3c2440_serial_drv = {
155         .probe          = s3c2440_serial_probe,
156         .remove         = s3c24xx_serial_remove,
157         .driver         = {
158                 .name   = "s3c2440-uart",
159                 .owner  = THIS_MODULE,
160         },
161 };
162
163 s3c24xx_console_init(&s3c2440_serial_drv, &s3c2440_uart_inf);
164
165 static int __init s3c2440_serial_init(void)
166 {
167         return s3c24xx_serial_init(&s3c2440_serial_drv, &s3c2440_uart_inf);
168 }
169
170 static void __exit s3c2440_serial_exit(void)
171 {
172         platform_driver_unregister(&s3c2440_serial_drv);
173 }
174
175 module_init(s3c2440_serial_init);
176 module_exit(s3c2440_serial_exit);
177
178 MODULE_DESCRIPTION("Samsung S3C2440,S3C2442 SoC Serial port driver");
179 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
180 MODULE_LICENSE("GPLi v2");
181 MODULE_ALIAS("platform:s3c2440-uart");