x86, efi: Set runtime_version to the EFI spec revision
[linux/fpc-iii.git] / arch / arm / mach-sa1100 / jornada720_ssp.c
blobb143c4659346d841d7249fc358b12272061e71af
1 /**
2 * arch/arm/mac-sa1100/jornada720_ssp.c
4 * Copyright (C) 2006/2007 Kristoffer Ericson <Kristoffer.Ericson@gmail.com>
5 * Copyright (C) 2006 Filip Zyzniewski <filip.zyzniewski@tefnet.pl>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 * SSP driver for the HP Jornada 710/720/728
14 #include <linux/delay.h>
15 #include <linux/errno.h>
16 #include <linux/init.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/sched.h>
21 #include <linux/io.h>
23 #include <mach/hardware.h>
24 #include <mach/jornada720.h>
25 #include <asm/hardware/ssp.h>
27 static DEFINE_SPINLOCK(jornada_ssp_lock);
28 static unsigned long jornada_ssp_flags;
30 /**
31 * jornada_ssp_reverse - reverses input byte
33 * we need to reverse all data we receive from the mcu due to its physical location
34 * returns : 01110111 -> 11101110
36 u8 inline jornada_ssp_reverse(u8 byte)
38 return
39 ((0x80 & byte) >> 7) |
40 ((0x40 & byte) >> 5) |
41 ((0x20 & byte) >> 3) |
42 ((0x10 & byte) >> 1) |
43 ((0x08 & byte) << 1) |
44 ((0x04 & byte) << 3) |
45 ((0x02 & byte) << 5) |
46 ((0x01 & byte) << 7);
48 EXPORT_SYMBOL(jornada_ssp_reverse);
50 /**
51 * jornada_ssp_byte - waits for ready ssp bus and sends byte
53 * waits for fifo buffer to clear and then transmits, if it doesn't then we will
54 * timeout after <timeout> rounds. Needs mcu running before its called.
56 * returns : %mcu output on success
57 * : %-ETIMEDOUT on timeout
59 int jornada_ssp_byte(u8 byte)
61 int timeout = 400000;
62 u16 ret;
64 while ((GPLR & GPIO_GPIO10)) {
65 if (!--timeout) {
66 printk(KERN_WARNING "SSP: timeout while waiting for transmit\n");
67 return -ETIMEDOUT;
69 cpu_relax();
72 ret = jornada_ssp_reverse(byte) << 8;
74 ssp_write_word(ret);
75 ssp_read_word(&ret);
77 return jornada_ssp_reverse(ret);
79 EXPORT_SYMBOL(jornada_ssp_byte);
81 /**
82 * jornada_ssp_inout - decide if input is command or trading byte
84 * returns : (jornada_ssp_byte(byte)) on success
85 * : %-ETIMEDOUT on timeout failure
87 int jornada_ssp_inout(u8 byte)
89 int ret, i;
91 /* true means command byte */
92 if (byte != TXDUMMY) {
93 ret = jornada_ssp_byte(byte);
94 /* Proper return to commands is TxDummy */
95 if (ret != TXDUMMY) {
96 for (i = 0; i < 256; i++)/* flushing bus */
97 if (jornada_ssp_byte(TXDUMMY) == -1)
98 break;
99 return -ETIMEDOUT;
101 } else /* Exchange TxDummy for data */
102 ret = jornada_ssp_byte(TXDUMMY);
104 return ret;
106 EXPORT_SYMBOL(jornada_ssp_inout);
109 * jornada_ssp_start - enable mcu
112 void jornada_ssp_start(void)
114 spin_lock_irqsave(&jornada_ssp_lock, jornada_ssp_flags);
115 GPCR = GPIO_GPIO25;
116 udelay(50);
117 return;
119 EXPORT_SYMBOL(jornada_ssp_start);
122 * jornada_ssp_end - disable mcu and turn off lock
125 void jornada_ssp_end(void)
127 GPSR = GPIO_GPIO25;
128 spin_unlock_irqrestore(&jornada_ssp_lock, jornada_ssp_flags);
129 return;
131 EXPORT_SYMBOL(jornada_ssp_end);
133 static int jornada_ssp_probe(struct platform_device *dev)
135 int ret;
137 GPSR = GPIO_GPIO25;
139 ret = ssp_init();
141 /* worked fine, lets not bother with anything else */
142 if (!ret) {
143 printk(KERN_INFO "SSP: device initialized with irq\n");
144 return ret;
147 printk(KERN_WARNING "SSP: initialization failed, trying non-irq solution \n");
149 /* init of Serial 4 port */
150 Ser4MCCR0 = 0;
151 Ser4SSCR0 = 0x0387;
152 Ser4SSCR1 = 0x18;
154 /* clear out any left over data */
155 ssp_flush();
157 /* enable MCU */
158 jornada_ssp_start();
160 /* see if return value makes sense */
161 ret = jornada_ssp_inout(GETBRIGHTNESS);
163 /* seems like it worked, just feed it with TxDummy to get rid of data */
164 if (ret == TXDUMMY)
165 jornada_ssp_inout(TXDUMMY);
167 jornada_ssp_end();
169 /* failed, lets just kill everything */
170 if (ret == -ETIMEDOUT) {
171 printk(KERN_WARNING "SSP: attempts failed, bailing\n");
172 ssp_exit();
173 return -ENODEV;
176 /* all fine */
177 printk(KERN_INFO "SSP: device initialized\n");
178 return 0;
181 static int jornada_ssp_remove(struct platform_device *dev)
183 /* Note that this doesn't actually remove the driver, since theres nothing to remove
184 * It just makes sure everything is turned off */
185 GPSR = GPIO_GPIO25;
186 ssp_exit();
187 return 0;
190 struct platform_driver jornadassp_driver = {
191 .probe = jornada_ssp_probe,
192 .remove = jornada_ssp_remove,
193 .driver = {
194 .name = "jornada_ssp",
198 static int __init jornada_ssp_init(void)
200 return platform_driver_register(&jornadassp_driver);
203 module_init(jornada_ssp_init);