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1/**
2 * arch/arm/mac-sa1100/jornada720_ssp.c
3 *
4 * Copyright (C) 2006/2007 Kristoffer Ericson <Kristoffer.Ericson@gmail.com>
5 * Copyright (C) 2006 Filip Zyzniewski <filip.zyzniewski@tefnet.pl>
6 *
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.
10 *
11 * SSP driver for the HP Jornada 710/720/728
12 */
13
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>
22
23#include <mach/hardware.h>
24#include <mach/jornada720.h>
25#include <asm/hardware/ssp.h>
26
27static DEFINE_SPINLOCK(jornada_ssp_lock);
28static unsigned long jornada_ssp_flags;
29
30/**
31 * jornada_ssp_reverse - reverses input byte
32 *
33 * we need to reverse all data we receive from the mcu due to its physical location
34 * returns : 01110111 -> 11101110
35 */
36u8 inline jornada_ssp_reverse(u8 byte)
37{
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);
47};
48EXPORT_SYMBOL(jornada_ssp_reverse);
49
50/**
51 * jornada_ssp_byte - waits for ready ssp bus and sends byte
52 *
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.
55 *
56 * returns : %mcu output on success
57 * : %-ETIMEDOUT on timeout
58 */
59int jornada_ssp_byte(u8 byte)
60{
61 int timeout = 400000;
62 u16 ret;
63
64 while ((GPLR & GPIO_GPIO10)) {
65 if (!--timeout) {
66 printk(KERN_WARNING "SSP: timeout while waiting for transmit\n");
67 return -ETIMEDOUT;
68 }
69 cpu_relax();
70 }
71
72 ret = jornada_ssp_reverse(byte) << 8;
73
74 ssp_write_word(ret);
75 ssp_read_word(&ret);
76
77 return jornada_ssp_reverse(ret);
78};
79EXPORT_SYMBOL(jornada_ssp_byte);
80
81/**
82 * jornada_ssp_inout - decide if input is command or trading byte
83 *
84 * returns : (jornada_ssp_byte(byte)) on success
85 * : %-ETIMEDOUT on timeout failure
86 */
87int jornada_ssp_inout(u8 byte)
88{
89 int ret, i;
90
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;
100 }
101 } else /* Exchange TxDummy for data */
102 ret = jornada_ssp_byte(TXDUMMY);
103
104 return ret;
105};
106EXPORT_SYMBOL(jornada_ssp_inout);
107
108/**
109 * jornada_ssp_start - enable mcu
110 *
111 */
112void jornada_ssp_start(void)
113{
114 spin_lock_irqsave(&jornada_ssp_lock, jornada_ssp_flags);
115 GPCR = GPIO_GPIO25;
116 udelay(50);
117 return;
118};
119EXPORT_SYMBOL(jornada_ssp_start);
120
121/**
122 * jornada_ssp_end - disable mcu and turn off lock
123 *
124 */
125void jornada_ssp_end(void)
126{
127 GPSR = GPIO_GPIO25;
128 spin_unlock_irqrestore(&jornada_ssp_lock, jornada_ssp_flags);
129 return;
130};
131EXPORT_SYMBOL(jornada_ssp_end);
132
133static int jornada_ssp_probe(struct platform_device *dev)
134{
135 int ret;
136
137 GPSR = GPIO_GPIO25;
138
139 ret = ssp_init();
140
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;
145 }
146
147 printk(KERN_WARNING "SSP: initialization failed, trying non-irq solution \n");
148
149 /* init of Serial 4 port */
150 Ser4MCCR0 = 0;
151 Ser4SSCR0 = 0x0387;
152 Ser4SSCR1 = 0x18;
153
154 /* clear out any left over data */
155 ssp_flush();
156
157 /* enable MCU */
158 jornada_ssp_start();
159
160 /* see if return value makes sense */
161 ret = jornada_ssp_inout(GETBRIGHTNESS);
162
163 /* seems like it worked, just feed it with TxDummy to get rid of data */
164 if (ret == TXDUMMY)
165 jornada_ssp_inout(TXDUMMY);
166
167 jornada_ssp_end();
168
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;
174 }
175
176 /* all fine */
177 printk(KERN_INFO "SSP: device initialized\n");
178 return 0;
179};
180
181static int jornada_ssp_remove(struct platform_device *dev)
182{
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;
188};
189
190struct platform_driver jornadassp_driver = {
191 .probe = jornada_ssp_probe,
192 .remove = jornada_ssp_remove,
193 .driver = {
194 .name = "jornada_ssp",
195 },
196};
197
198static int __init jornada_ssp_init(void)
199{
200 return platform_driver_register(&jornadassp_driver);
201}
202
203module_init(jornada_ssp_init);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * arch/arm/mac-sa1100/jornada720_ssp.c
4 *
5 * Copyright (C) 2006/2007 Kristoffer Ericson <Kristoffer.Ericson@gmail.com>
6 * Copyright (C) 2006 Filip Zyzniewski <filip.zyzniewski@tefnet.pl>
7 *
8 * SSP driver for the HP Jornada 710/720/728
9 */
10
11#include <linux/delay.h>
12#include <linux/errno.h>
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/platform_device.h>
17#include <linux/sched.h>
18#include <linux/io.h>
19
20#include <mach/hardware.h>
21#include <mach/jornada720.h>
22#include <asm/hardware/ssp.h>
23
24static DEFINE_SPINLOCK(jornada_ssp_lock);
25static unsigned long jornada_ssp_flags;
26
27/**
28 * jornada_ssp_reverse - reverses input byte
29 * @byte: input byte to reverse
30 *
31 * we need to reverse all data we receive from the mcu due to its physical location
32 * returns : 01110111 -> 11101110
33 */
34inline u8 jornada_ssp_reverse(u8 byte)
35{
36 return
37 ((0x80 & byte) >> 7) |
38 ((0x40 & byte) >> 5) |
39 ((0x20 & byte) >> 3) |
40 ((0x10 & byte) >> 1) |
41 ((0x08 & byte) << 1) |
42 ((0x04 & byte) << 3) |
43 ((0x02 & byte) << 5) |
44 ((0x01 & byte) << 7);
45};
46EXPORT_SYMBOL(jornada_ssp_reverse);
47
48/**
49 * jornada_ssp_byte - waits for ready ssp bus and sends byte
50 * @byte: input byte to transmit
51 *
52 * waits for fifo buffer to clear and then transmits, if it doesn't then we will
53 * timeout after <timeout> rounds. Needs mcu running before its called.
54 *
55 * returns : %mcu output on success
56 * : %-ETIMEDOUT on timeout
57 */
58int jornada_ssp_byte(u8 byte)
59{
60 int timeout = 400000;
61 u16 ret;
62
63 while ((GPLR & GPIO_GPIO10)) {
64 if (!--timeout) {
65 printk(KERN_WARNING "SSP: timeout while waiting for transmit\n");
66 return -ETIMEDOUT;
67 }
68 cpu_relax();
69 }
70
71 ret = jornada_ssp_reverse(byte) << 8;
72
73 ssp_write_word(ret);
74 ssp_read_word(&ret);
75
76 return jornada_ssp_reverse(ret);
77};
78EXPORT_SYMBOL(jornada_ssp_byte);
79
80/**
81 * jornada_ssp_inout - decide if input is command or trading byte
82 * @byte: input byte to send (may be %TXDUMMY)
83 *
84 * returns : (jornada_ssp_byte(byte)) on success
85 * : %-ETIMEDOUT on timeout failure
86 */
87int jornada_ssp_inout(u8 byte)
88{
89 int ret, i;
90
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;
100 }
101 } else /* Exchange TxDummy for data */
102 ret = jornada_ssp_byte(TXDUMMY);
103
104 return ret;
105};
106EXPORT_SYMBOL(jornada_ssp_inout);
107
108/**
109 * jornada_ssp_start - enable mcu
110 *
111 */
112void jornada_ssp_start(void)
113{
114 spin_lock_irqsave(&jornada_ssp_lock, jornada_ssp_flags);
115 GPCR = GPIO_GPIO25;
116 udelay(50);
117 return;
118};
119EXPORT_SYMBOL(jornada_ssp_start);
120
121/**
122 * jornada_ssp_end - disable mcu and turn off lock
123 *
124 */
125void jornada_ssp_end(void)
126{
127 GPSR = GPIO_GPIO25;
128 spin_unlock_irqrestore(&jornada_ssp_lock, jornada_ssp_flags);
129 return;
130};
131EXPORT_SYMBOL(jornada_ssp_end);
132
133static int jornada_ssp_probe(struct platform_device *dev)
134{
135 int ret;
136
137 GPSR = GPIO_GPIO25;
138
139 ret = ssp_init();
140
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;
145 }
146
147 printk(KERN_WARNING "SSP: initialization failed, trying non-irq solution \n");
148
149 /* init of Serial 4 port */
150 Ser4MCCR0 = 0;
151 Ser4SSCR0 = 0x0387;
152 Ser4SSCR1 = 0x18;
153
154 /* clear out any left over data */
155 ssp_flush();
156
157 /* enable MCU */
158 jornada_ssp_start();
159
160 /* see if return value makes sense */
161 ret = jornada_ssp_inout(GETBRIGHTNESS);
162
163 /* seems like it worked, just feed it with TxDummy to get rid of data */
164 if (ret == TXDUMMY)
165 jornada_ssp_inout(TXDUMMY);
166
167 jornada_ssp_end();
168
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;
174 }
175
176 /* all fine */
177 printk(KERN_INFO "SSP: device initialized\n");
178 return 0;
179};
180
181static void jornada_ssp_remove(struct platform_device *dev)
182{
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};
188
189struct platform_driver jornadassp_driver = {
190 .probe = jornada_ssp_probe,
191 .remove = jornada_ssp_remove,
192 .driver = {
193 .name = "jornada_ssp",
194 },
195};
196
197static int __init jornada_ssp_init(void)
198{
199 return platform_driver_register(&jornadassp_driver);
200}
201
202module_init(jornada_ssp_init);