Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[linux-2.6] / arch / powerpc / platforms / embedded6xx / ls_uart.c
1 /*
2  * AVR power-management chip interface for the Buffalo Linkstation /
3  * Kurobox Platform.
4  *
5  * Author: 2006 (c) G. Liakhovetski
6  *       g.liakhovetski@gmx.de
7  *
8  * This file is licensed under the terms of the GNU General Public License
9  * version 2.  This program is licensed "as is" without any warranty of
10  * any kind, whether express or implied.
11  */
12 #include <linux/workqueue.h>
13 #include <linux/string.h>
14 #include <linux/delay.h>
15 #include <linux/serial_reg.h>
16 #include <linux/serial_8250.h>
17 #include <asm/io.h>
18 #include <asm/prom.h>
19 #include <asm/termbits.h>
20
21 #include "mpc10x.h"
22
23 static void __iomem *avr_addr;
24 static unsigned long avr_clock;
25
26 static struct work_struct wd_work;
27
28 static void wd_stop(struct work_struct *unused)
29 {
30         const char string[] = "AAAAFFFFJJJJ>>>>VVVV>>>>ZZZZVVVVKKKK";
31         int i = 0, rescue = 8;
32         int len = strlen(string);
33
34         while (rescue--) {
35                 int j;
36                 char lsr = in_8(avr_addr + UART_LSR);
37
38                 if (lsr & (UART_LSR_THRE | UART_LSR_TEMT)) {
39                         for (j = 0; j < 16 && i < len; j++, i++)
40                                 out_8(avr_addr + UART_TX, string[i]);
41                         if (i == len) {
42                                 /* Read "OK" back: 4ms for the last "KKKK"
43                                    plus a couple bytes back */
44                                 msleep(7);
45                                 printk("linkstation: disarming the AVR watchdog: ");
46                                 while (in_8(avr_addr + UART_LSR) & UART_LSR_DR)
47                                         printk("%c", in_8(avr_addr + UART_RX));
48                                 break;
49                         }
50                 }
51                 msleep(17);
52         }
53         printk("\n");
54 }
55
56 #define AVR_QUOT(clock) ((clock) + 8 * 9600) / (16 * 9600)
57
58 void avr_uart_configure(void)
59 {
60         unsigned char cval = UART_LCR_WLEN8;
61         unsigned int quot = AVR_QUOT(avr_clock);
62
63         if (!avr_addr || !avr_clock)
64                 return;
65
66         out_8(avr_addr + UART_LCR, cval);                       /* initialise UART */
67         out_8(avr_addr + UART_MCR, 0);
68         out_8(avr_addr + UART_IER, 0);
69
70         cval |= UART_LCR_STOP | UART_LCR_PARITY | UART_LCR_EPAR;
71
72         out_8(avr_addr + UART_LCR, cval);                       /* Set character format */
73
74         out_8(avr_addr + UART_LCR, cval | UART_LCR_DLAB);       /* set DLAB */
75         out_8(avr_addr + UART_DLL, quot & 0xff);                /* LS of divisor */
76         out_8(avr_addr + UART_DLM, quot >> 8);                  /* MS of divisor */
77         out_8(avr_addr + UART_LCR, cval);                       /* reset DLAB */
78         out_8(avr_addr + UART_FCR, UART_FCR_ENABLE_FIFO);       /* enable FIFO */
79 }
80
81 void avr_uart_send(const char c)
82 {
83         if (!avr_addr || !avr_clock)
84                 return;
85
86         out_8(avr_addr + UART_TX, c);
87         out_8(avr_addr + UART_TX, c);
88         out_8(avr_addr + UART_TX, c);
89         out_8(avr_addr + UART_TX, c);
90 }
91
92 static void __init ls_uart_init(void)
93 {
94         local_irq_disable();
95
96 #ifndef CONFIG_SERIAL_8250
97         out_8(avr_addr + UART_FCR, UART_FCR_ENABLE_FIFO);       /* enable FIFO */
98         out_8(avr_addr + UART_FCR, UART_FCR_ENABLE_FIFO |
99               UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);       /* clear FIFOs */
100         out_8(avr_addr + UART_FCR, 0);
101         out_8(avr_addr + UART_IER, 0);
102
103         /* Clear up interrupts */
104         (void) in_8(avr_addr + UART_LSR);
105         (void) in_8(avr_addr + UART_RX);
106         (void) in_8(avr_addr + UART_IIR);
107         (void) in_8(avr_addr + UART_MSR);
108 #endif
109         avr_uart_configure();
110
111         local_irq_enable();
112 }
113
114 static int __init ls_uarts_init(void)
115 {
116         struct device_node *avr;
117         phys_addr_t phys_addr;
118         int len;
119
120         avr = of_find_node_by_path("/soc10x/serial@80004500");
121         if (!avr)
122                 return -EINVAL;
123
124         avr_clock = *(u32*)of_get_property(avr, "clock-frequency", &len);
125         phys_addr = ((u32*)of_get_property(avr, "reg", &len))[0];
126
127         if (!avr_clock || !phys_addr)
128                 return -EINVAL;
129
130         avr_addr = ioremap(phys_addr, 32);
131         if (!avr_addr)
132                 return -EFAULT;
133
134         ls_uart_init();
135
136         INIT_WORK(&wd_work, wd_stop);
137         schedule_work(&wd_work);
138
139         return 0;
140 }
141
142 machine_late_initcall(linkstation, ls_uarts_init);