kernel-fxtec-pro1x/arch/arm/mach-pxa/corgi_ssp.c
Richard Purdie 608c783aaa [ARM] 3479/1: Corgi SSP: Fix potential concurrent access problem
Patch from Richard Purdie

corgi_ssp_probe() should not access GPDR directly but should use
pxa_gpio_mode() which has appropriate locking and other safeguards.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-04-18 23:18:54 +01:00

256 lines
6.6 KiB
C

/*
* SSP control code for Sharp Corgi devices
*
* Copyright (c) 2004-2005 Richard Purdie
*
* 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/sched.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <asm/hardware.h>
#include <asm/mach-types.h>
#include <asm/arch/ssp.h>
#include <asm/arch/pxa-regs.h>
#include "sharpsl.h"
static DEFINE_SPINLOCK(corgi_ssp_lock);
static struct ssp_dev corgi_ssp_dev;
static struct ssp_state corgi_ssp_state;
static struct corgissp_machinfo *ssp_machinfo;
/*
* There are three devices connected to the SSP interface:
* 1. A touchscreen controller (TI ADS7846 compatible)
* 2. An LCD contoller (with some Backlight functionality)
* 3. A battery moinitoring IC (Maxim MAX1111)
*
* Each device uses a different speed/mode of communication.
*
* The touchscreen is very sensitive and the most frequently used
* so the port is left configured for this.
*
* Devices are selected using Chip Selects on GPIOs.
*/
/*
* ADS7846 Routines
*/
unsigned long corgi_ssp_ads7846_putget(ulong data)
{
unsigned long ret,flag;
spin_lock_irqsave(&corgi_ssp_lock, flag);
GPCR(ssp_machinfo->cs_ads7846) = GPIO_bit(ssp_machinfo->cs_ads7846);
ssp_write_word(&corgi_ssp_dev,data);
ret = ssp_read_word(&corgi_ssp_dev);
GPSR(ssp_machinfo->cs_ads7846) = GPIO_bit(ssp_machinfo->cs_ads7846);
spin_unlock_irqrestore(&corgi_ssp_lock, flag);
return ret;
}
/*
* NOTE: These functions should always be called in interrupt context
* and use the _lock and _unlock functions. They are very time sensitive.
*/
void corgi_ssp_ads7846_lock(void)
{
spin_lock(&corgi_ssp_lock);
GPCR(ssp_machinfo->cs_ads7846) = GPIO_bit(ssp_machinfo->cs_ads7846);
}
void corgi_ssp_ads7846_unlock(void)
{
GPSR(ssp_machinfo->cs_ads7846) = GPIO_bit(ssp_machinfo->cs_ads7846);
spin_unlock(&corgi_ssp_lock);
}
void corgi_ssp_ads7846_put(ulong data)
{
ssp_write_word(&corgi_ssp_dev,data);
}
unsigned long corgi_ssp_ads7846_get(void)
{
return ssp_read_word(&corgi_ssp_dev);
}
EXPORT_SYMBOL(corgi_ssp_ads7846_putget);
EXPORT_SYMBOL(corgi_ssp_ads7846_lock);
EXPORT_SYMBOL(corgi_ssp_ads7846_unlock);
EXPORT_SYMBOL(corgi_ssp_ads7846_put);
EXPORT_SYMBOL(corgi_ssp_ads7846_get);
/*
* LCD/Backlight Routines
*/
unsigned long corgi_ssp_dac_put(ulong data)
{
unsigned long flag, sscr1 = SSCR1_SPH;
spin_lock_irqsave(&corgi_ssp_lock, flag);
if (machine_is_spitz() || machine_is_akita() || machine_is_borzoi())
sscr1 = 0;
ssp_disable(&corgi_ssp_dev);
ssp_config(&corgi_ssp_dev, (SSCR0_Motorola | (SSCR0_DSS & 0x07 )), sscr1, 0, SSCR0_SerClkDiv(ssp_machinfo->clk_lcdcon));
ssp_enable(&corgi_ssp_dev);
GPCR(ssp_machinfo->cs_lcdcon) = GPIO_bit(ssp_machinfo->cs_lcdcon);
ssp_write_word(&corgi_ssp_dev,data);
/* Read null data back from device to prevent SSP overflow */
ssp_read_word(&corgi_ssp_dev);
GPSR(ssp_machinfo->cs_lcdcon) = GPIO_bit(ssp_machinfo->cs_lcdcon);
ssp_disable(&corgi_ssp_dev);
ssp_config(&corgi_ssp_dev, (SSCR0_National | (SSCR0_DSS & 0x0b )), 0, 0, SSCR0_SerClkDiv(ssp_machinfo->clk_ads7846));
ssp_enable(&corgi_ssp_dev);
spin_unlock_irqrestore(&corgi_ssp_lock, flag);
return 0;
}
void corgi_ssp_lcdtg_send(u8 adrs, u8 data)
{
corgi_ssp_dac_put(((adrs & 0x07) << 5) | (data & 0x1f));
}
void corgi_ssp_blduty_set(int duty)
{
corgi_ssp_lcdtg_send(0x02,duty);
}
EXPORT_SYMBOL(corgi_ssp_lcdtg_send);
EXPORT_SYMBOL(corgi_ssp_blduty_set);
/*
* Max1111 Routines
*/
int corgi_ssp_max1111_get(ulong data)
{
unsigned long flag;
int voltage,voltage1,voltage2;
spin_lock_irqsave(&corgi_ssp_lock, flag);
GPCR(ssp_machinfo->cs_max1111) = GPIO_bit(ssp_machinfo->cs_max1111);
ssp_disable(&corgi_ssp_dev);
ssp_config(&corgi_ssp_dev, (SSCR0_Motorola | (SSCR0_DSS & 0x07 )), 0, 0, SSCR0_SerClkDiv(ssp_machinfo->clk_max1111));
ssp_enable(&corgi_ssp_dev);
udelay(1);
/* TB1/RB1 */
ssp_write_word(&corgi_ssp_dev,data);
ssp_read_word(&corgi_ssp_dev); /* null read */
/* TB12/RB2 */
ssp_write_word(&corgi_ssp_dev,0);
voltage1=ssp_read_word(&corgi_ssp_dev);
/* TB13/RB3*/
ssp_write_word(&corgi_ssp_dev,0);
voltage2=ssp_read_word(&corgi_ssp_dev);
ssp_disable(&corgi_ssp_dev);
ssp_config(&corgi_ssp_dev, (SSCR0_National | (SSCR0_DSS & 0x0b )), 0, 0, SSCR0_SerClkDiv(ssp_machinfo->clk_ads7846));
ssp_enable(&corgi_ssp_dev);
GPSR(ssp_machinfo->cs_max1111) = GPIO_bit(ssp_machinfo->cs_max1111);
spin_unlock_irqrestore(&corgi_ssp_lock, flag);
if (voltage1 & 0xc0 || voltage2 & 0x3f)
voltage = -1;
else
voltage = ((voltage1 << 2) & 0xfc) | ((voltage2 >> 6) & 0x03);
return voltage;
}
EXPORT_SYMBOL(corgi_ssp_max1111_get);
/*
* Support Routines
*/
void __init corgi_ssp_set_machinfo(struct corgissp_machinfo *machinfo)
{
ssp_machinfo = machinfo;
}
static int __init corgi_ssp_probe(struct platform_device *dev)
{
int ret;
/* Chip Select - Disable All */
pxa_gpio_mode(ssp_machinfo->cs_lcdcon | GPIO_OUT | GPIO_DFLT_HIGH);
pxa_gpio_mode(ssp_machinfo->cs_max1111 | GPIO_OUT | GPIO_DFLT_HIGH);
pxa_gpio_mode(ssp_machinfo->cs_ads7846 | GPIO_OUT | GPIO_DFLT_HIGH);
ret = ssp_init(&corgi_ssp_dev, ssp_machinfo->port, 0);
if (ret)
printk(KERN_ERR "Unable to register SSP handler!\n");
else {
ssp_disable(&corgi_ssp_dev);
ssp_config(&corgi_ssp_dev, (SSCR0_National | (SSCR0_DSS & 0x0b )), 0, 0, SSCR0_SerClkDiv(ssp_machinfo->clk_ads7846));
ssp_enable(&corgi_ssp_dev);
}
return ret;
}
static int corgi_ssp_remove(struct platform_device *dev)
{
ssp_exit(&corgi_ssp_dev);
return 0;
}
static int corgi_ssp_suspend(struct platform_device *dev, pm_message_t state)
{
ssp_flush(&corgi_ssp_dev);
ssp_save_state(&corgi_ssp_dev,&corgi_ssp_state);
return 0;
}
static int corgi_ssp_resume(struct platform_device *dev)
{
GPSR(ssp_machinfo->cs_lcdcon) = GPIO_bit(ssp_machinfo->cs_lcdcon); /* High - Disable LCD Control/Timing Gen */
GPSR(ssp_machinfo->cs_max1111) = GPIO_bit(ssp_machinfo->cs_max1111); /* High - Disable MAX1111*/
GPSR(ssp_machinfo->cs_ads7846) = GPIO_bit(ssp_machinfo->cs_ads7846); /* High - Disable ADS7846*/
ssp_restore_state(&corgi_ssp_dev,&corgi_ssp_state);
ssp_enable(&corgi_ssp_dev);
return 0;
}
static struct platform_driver corgissp_driver = {
.probe = corgi_ssp_probe,
.remove = corgi_ssp_remove,
.suspend = corgi_ssp_suspend,
.resume = corgi_ssp_resume,
.driver = {
.name = "corgi-ssp",
},
};
int __init corgi_ssp_init(void)
{
return platform_driver_register(&corgissp_driver);
}
arch_initcall(corgi_ssp_init);