diff options
Diffstat (limited to 'arch/arm/mach-sa1100/jornada720_mcu.c')
| -rw-r--r-- | arch/arm/mach-sa1100/jornada720_mcu.c | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/arch/arm/mach-sa1100/jornada720_mcu.c b/arch/arm/mach-sa1100/jornada720_mcu.c new file mode 100644 index 00000000000000..e6f92d65f1ae7f --- /dev/null +++ b/arch/arm/mach-sa1100/jornada720_mcu.c @@ -0,0 +1,248 @@ +/* + * arch/arm/mach-sa1100/jornada720_mcu.c + * + * HP Jornada 720 Microprocessor Control Unit driver + * + * Copyright (C) 2006 Filip Zyzniewski <filip.zyzniewski@tefnet.pl> + * Copyright (C) 2005 Michael Gernoth <michael@gernoth.net> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/device.h> +#include <linux/platform_device.h> + +#include <asm/hardware.h> +#include <asm/hardware/ssp.h> +#include "ssp.c" +#include <asm/arch/jornada720_mcu.h> + +MODULE_AUTHOR("Filip Zyzniewski <filip.zyzniewski@tefnet.pl>"); +MODULE_DESCRIPTION("HP Jornada 720 Microprocessor Controller Unit driver"); +MODULE_LICENSE("GPL"); + +/* + * HP Documentation referred in this file: + * http://www.jlime.com/downloads/development/docs/jornada7xx/jornada720.txt + */ + + +/* + * we have to lock to avoid starting + * second transmission during one taking place + */ +static spinlock_t jornada720_mcu_lock = SPIN_LOCK_UNLOCKED; +static unsigned long jornada720_mcu_flags; + + +u8 inline jornada720_mcu_reverse(u8 x) +{ + /* byte ghijklmn becomes nmlkjihg (line 205 of HP's doc) */ + return + ((0x80 & x) >> 7) | + ((0x40 & x) >> 5) | + ((0x20 & x) >> 3) | + ((0x10 & x) >> 1) | + ((0x08 & x) << 1) | + ((0x04 & x) << 3) | + ((0x02 & x) << 5) | + ((0x01 & x) << 7) ; +} + + +int jornada720_mcu_byte(u8 byte) +{ + u16 ret; + int timeout = 400000; + + /* wating for GPIO 10 to go low (line 197 of HP's doc) */ + while ((GPLR & GPIO_GPIO10)) { + if (!--timeout) { + printk("jornada720_mcu_byte ret -ETIMEDOUT\n"); + return -ETIMEDOUT; + } + cpu_relax(); + } + + ret=jornada720_mcu_reverse(byte) << 8; + + ssp_write_word(ret); + ssp_read_word(&ret); + + return jornada720_mcu_reverse(ret); +} + +EXPORT_SYMBOL(jornada720_mcu_byte); + + +/* + * WARNING: remember to jornada720_mcu_end() after every + * jornada720_mcu_start() or you will deadlock! + */ + +int jornada720_mcu_start(u8 byte) +{ + int i; + + /* we don't want other access to the MCU now */ + spin_lock_irqsave(&jornada720_mcu_lock, jornada720_mcu_flags); + + /* clear to enable MCU (line 194 of HP's doc) */ + GPCR = GPIO_GPIO25; + + /* we should always get TxDummy after first request */ + if (jornada720_mcu_byte(byte) != jornada720_mcu_TxDummy) + { + printk(KERN_WARNING "jornada720_mcu: leftover MCU data, flushing\n"); + for (i = 0; i < 256; i++) + if (jornada720_mcu_read() == -1) + break; + return -1; + } + + return 0; +} + +EXPORT_SYMBOL(jornada720_mcu_start); + + +void jornada720_mcu_end(void) +{ + /* end of transmission (line 203 of HP's doc) */ + GPSR = GPIO_GPIO25; + spin_unlock_irqrestore(&jornada720_mcu_lock, jornada720_mcu_flags); +} + +EXPORT_SYMBOL(jornada720_mcu_end); + + +/* Jornada 720 devices accessed by the MCU */ +static struct device jornada720_mcu_bus_devices[] = { + /* keyboard */ + { .bus_id = jornada720_mcu_bus_id_kbd }, + + /* touchscreen */ + { .bus_id = jornada720_mcu_bus_id_ts }, + + /* apm (batteries) */ + { .bus_id = jornada720_mcu_bus_id_apm }, + + /* backlight */ + { .bus_id = jornada720_mcu_bus_id_bl }, + + /* lcd display */ + { .bus_id = jornada720_mcu_bus_id_lcd }, +}; + +static int jornada720_mcu_bus_match(struct device *dev, struct device_driver *drv) +{ + return ! strcmp(dev->bus_id, drv->name); +} + +struct bus_type jornada720_mcu_bus_type = { + .name = "jornada720_mcu_bus", + .match = jornada720_mcu_bus_match, +}; + +EXPORT_SYMBOL(jornada720_mcu_bus_type); + + +void jornada720_mcu_bus_device_release(struct device *dev) +{ + /* + * those device structures are static, so we don't + * have anything to free + */ +} + +static int __init jornada720_mcu_probe(struct platform_device *dev) +{ + int ret, i; + + /* we don't want any data yet (line 203 of HP's doc) */ + GPSR = GPIO_GPIO25; + ret=ssp_init(); + if (ret) + return ret; + + /* initialization of MCU serial interface (line 182 of HP's doc) */ + Ser4MCCR0 = 0; + Ser4SSCR0 = 0x0387; + Ser4SSCR1 = 0x18; + + ssp_flush(); + + /* test of MCU presence */ + ret = jornada720_mcu_start(jornada720_mcu_GetBrightness); + if(!ret) jornada720_mcu_read(); + jornada720_mcu_end(); + + if(ret < 0) { + ssp_exit(); + return -ENODEV; + } + + /* registering devices accessible through this bus */ + for(i=0; i<ARRAY_SIZE(jornada720_mcu_bus_devices); i++) { + jornada720_mcu_bus_devices[i].bus = &jornada720_mcu_bus_type; + jornada720_mcu_bus_devices[i].parent = &(dev->dev); + jornada720_mcu_bus_devices[i].release = jornada720_mcu_bus_device_release; + ret = device_register(jornada720_mcu_bus_devices + i); + if (ret) + break; + } + + if (ret) { + for(; i <= 0; i--) { + device_unregister(jornada720_mcu_bus_devices + i); + } + ssp_exit(); + } + + return ret; +} + +static int jornada720_mcu_remove(struct platform_device *dev) +{ + int i; + for(i=0; i<ARRAY_SIZE(jornada720_mcu_bus_devices); i++) + device_unregister(jornada720_mcu_bus_devices + i); + /* we don't want data anymore (line 203 of HP's doc) */ + GPSR = GPIO_GPIO25; + ssp_exit(); + return 0; +} + +struct platform_driver jornada720_mcu_driver = { + .probe = jornada720_mcu_probe, + .remove = jornada720_mcu_remove, + .driver = { + .name = "jornada720_mcu", + }, +}; + +static int __init jornada720_mcu_init(void) +{ + int ret = bus_register(&jornada720_mcu_bus_type); + if(!ret) { + ret=platform_driver_register(&jornada720_mcu_driver); + if(ret) + bus_unregister(&jornada720_mcu_bus_type); + } + return ret; +} + +static void __exit jornada720_mcu_exit(void) +{ + bus_unregister(&jornada720_mcu_bus_type); + platform_driver_unregister(&jornada720_mcu_driver); +} + +module_init(jornada720_mcu_init); +module_exit(jornada720_mcu_exit); |