Kristoffer Ericson | 69ebb22 | 2007-07-20 18:22:57 +0100 | [diff] [blame] | 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> |
Kristoffer Ericson | 69ebb22 | 2007-07-20 18:22:57 +0100 | [diff] [blame] | 21 | |
Russell King | a09e64f | 2008-08-05 16:14:15 +0100 | [diff] [blame] | 22 | #include <mach/hardware.h> |
Russell King | a09e64f | 2008-08-05 16:14:15 +0100 | [diff] [blame] | 23 | #include <mach/jornada720.h> |
Kristoffer Ericson | 58005b3 | 2008-09-18 12:19:39 +0100 | [diff] [blame] | 24 | #include <asm/hardware/ssp.h> |
Kristoffer Ericson | 69ebb22 | 2007-07-20 18:22:57 +0100 | [diff] [blame] | 25 | |
| 26 | static DEFINE_SPINLOCK(jornada_ssp_lock); |
| 27 | static unsigned long jornada_ssp_flags; |
| 28 | |
| 29 | /** |
| 30 | * jornada_ssp_reverse - reverses input byte |
| 31 | * |
| 32 | * we need to reverse all data we recieve from the mcu due to its physical location |
| 33 | * returns : 01110111 -> 11101110 |
| 34 | */ |
| 35 | u8 inline jornada_ssp_reverse(u8 byte) |
| 36 | { |
| 37 | return |
| 38 | ((0x80 & byte) >> 7) | |
| 39 | ((0x40 & byte) >> 5) | |
| 40 | ((0x20 & byte) >> 3) | |
| 41 | ((0x10 & byte) >> 1) | |
| 42 | ((0x08 & byte) << 1) | |
| 43 | ((0x04 & byte) << 3) | |
| 44 | ((0x02 & byte) << 5) | |
| 45 | ((0x01 & byte) << 7); |
| 46 | }; |
| 47 | EXPORT_SYMBOL(jornada_ssp_reverse); |
| 48 | |
| 49 | /** |
| 50 | * jornada_ssp_byte - waits for ready ssp bus and sends byte |
| 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 |
Jean Delvare | 3ac49a1 | 2009-06-04 16:20:28 +0200 | [diff] [blame] | 56 | * : %-ETIMEDOUT on timeout |
Kristoffer Ericson | 69ebb22 | 2007-07-20 18:22:57 +0100 | [diff] [blame] | 57 | */ |
| 58 | int 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 | }; |
| 78 | EXPORT_SYMBOL(jornada_ssp_byte); |
| 79 | |
| 80 | /** |
| 81 | * jornada_ssp_inout - decide if input is command or trading byte |
| 82 | * |
| 83 | * returns : (jornada_ssp_byte(byte)) on success |
Jean Delvare | 3ac49a1 | 2009-06-04 16:20:28 +0200 | [diff] [blame] | 84 | * : %-ETIMEDOUT on timeout failure |
Kristoffer Ericson | 69ebb22 | 2007-07-20 18:22:57 +0100 | [diff] [blame] | 85 | */ |
| 86 | int jornada_ssp_inout(u8 byte) |
| 87 | { |
| 88 | int ret, i; |
| 89 | |
| 90 | /* true means command byte */ |
| 91 | if (byte != TXDUMMY) { |
| 92 | ret = jornada_ssp_byte(byte); |
| 93 | /* Proper return to commands is TxDummy */ |
| 94 | if (ret != TXDUMMY) { |
| 95 | for (i = 0; i < 256; i++)/* flushing bus */ |
| 96 | if (jornada_ssp_byte(TXDUMMY) == -1) |
| 97 | break; |
| 98 | return -ETIMEDOUT; |
| 99 | } |
| 100 | } else /* Exchange TxDummy for data */ |
| 101 | ret = jornada_ssp_byte(TXDUMMY); |
| 102 | |
| 103 | return ret; |
| 104 | }; |
| 105 | EXPORT_SYMBOL(jornada_ssp_inout); |
| 106 | |
| 107 | /** |
| 108 | * jornada_ssp_start - enable mcu |
| 109 | * |
| 110 | */ |
Kristoffer Ericson | 58005b3 | 2008-09-18 12:19:39 +0100 | [diff] [blame] | 111 | void jornada_ssp_start(void) |
Kristoffer Ericson | 69ebb22 | 2007-07-20 18:22:57 +0100 | [diff] [blame] | 112 | { |
| 113 | spin_lock_irqsave(&jornada_ssp_lock, jornada_ssp_flags); |
| 114 | GPCR = GPIO_GPIO25; |
| 115 | udelay(50); |
Kristoffer Ericson | 58005b3 | 2008-09-18 12:19:39 +0100 | [diff] [blame] | 116 | return; |
Kristoffer Ericson | 69ebb22 | 2007-07-20 18:22:57 +0100 | [diff] [blame] | 117 | }; |
| 118 | EXPORT_SYMBOL(jornada_ssp_start); |
| 119 | |
| 120 | /** |
| 121 | * jornada_ssp_end - disable mcu and turn off lock |
| 122 | * |
| 123 | */ |
Kristoffer Ericson | 58005b3 | 2008-09-18 12:19:39 +0100 | [diff] [blame] | 124 | void jornada_ssp_end(void) |
Kristoffer Ericson | 69ebb22 | 2007-07-20 18:22:57 +0100 | [diff] [blame] | 125 | { |
| 126 | GPSR = GPIO_GPIO25; |
| 127 | spin_unlock_irqrestore(&jornada_ssp_lock, jornada_ssp_flags); |
Kristoffer Ericson | 58005b3 | 2008-09-18 12:19:39 +0100 | [diff] [blame] | 128 | return; |
Kristoffer Ericson | 69ebb22 | 2007-07-20 18:22:57 +0100 | [diff] [blame] | 129 | }; |
| 130 | EXPORT_SYMBOL(jornada_ssp_end); |
| 131 | |
Uwe Kleine-König | 91a99df | 2010-02-04 20:56:49 +0100 | [diff] [blame] | 132 | static int __devinit jornada_ssp_probe(struct platform_device *dev) |
Kristoffer Ericson | 69ebb22 | 2007-07-20 18:22:57 +0100 | [diff] [blame] | 133 | { |
| 134 | int ret; |
| 135 | |
| 136 | GPSR = GPIO_GPIO25; |
| 137 | |
| 138 | ret = ssp_init(); |
| 139 | |
| 140 | /* worked fine, lets not bother with anything else */ |
| 141 | if (!ret) { |
| 142 | printk(KERN_INFO "SSP: device initialized with irq\n"); |
| 143 | return ret; |
| 144 | } |
| 145 | |
| 146 | printk(KERN_WARNING "SSP: initialization failed, trying non-irq solution \n"); |
| 147 | |
| 148 | /* init of Serial 4 port */ |
| 149 | Ser4MCCR0 = 0; |
| 150 | Ser4SSCR0 = 0x0387; |
| 151 | Ser4SSCR1 = 0x18; |
| 152 | |
| 153 | /* clear out any left over data */ |
| 154 | ssp_flush(); |
| 155 | |
| 156 | /* enable MCU */ |
| 157 | jornada_ssp_start(); |
| 158 | |
| 159 | /* see if return value makes sense */ |
| 160 | ret = jornada_ssp_inout(GETBRIGHTNESS); |
| 161 | |
| 162 | /* seems like it worked, just feed it with TxDummy to get rid of data */ |
Kristoffer Ericson | 219e3dc | 2007-07-26 07:41:12 +0100 | [diff] [blame] | 163 | if (ret == TXDUMMY) |
Kristoffer Ericson | 69ebb22 | 2007-07-20 18:22:57 +0100 | [diff] [blame] | 164 | jornada_ssp_inout(TXDUMMY); |
| 165 | |
| 166 | jornada_ssp_end(); |
| 167 | |
| 168 | /* failed, lets just kill everything */ |
| 169 | if (ret == -ETIMEDOUT) { |
| 170 | printk(KERN_WARNING "SSP: attempts failed, bailing\n"); |
| 171 | ssp_exit(); |
| 172 | return -ENODEV; |
| 173 | } |
| 174 | |
| 175 | /* all fine */ |
| 176 | printk(KERN_INFO "SSP: device initialized\n"); |
| 177 | return 0; |
| 178 | }; |
| 179 | |
| 180 | static int jornada_ssp_remove(struct platform_device *dev) |
| 181 | { |
| 182 | /* Note that this doesnt actually remove the driver, since theres nothing to remove |
| 183 | * It just makes sure everything is turned off */ |
| 184 | GPSR = GPIO_GPIO25; |
| 185 | ssp_exit(); |
| 186 | return 0; |
| 187 | }; |
| 188 | |
| 189 | struct platform_driver jornadassp_driver = { |
| 190 | .probe = jornada_ssp_probe, |
| 191 | .remove = jornada_ssp_remove, |
| 192 | .driver = { |
| 193 | .name = "jornada_ssp", |
| 194 | }, |
| 195 | }; |
| 196 | |
| 197 | static int __init jornada_ssp_init(void) |
| 198 | { |
| 199 | return platform_driver_register(&jornadassp_driver); |
| 200 | } |