linux/arch/arm/mach-pxa/corgi_pm.c
Robert Jarzmik ca26475bf0 ARM: pxa: fix GPIO double shifts
The commit 9bf448c66d ("ARM: pxa: use generic gpio operation instead of
gpio register") from Oct 17, 2011, leads to the following static checker
warning:
  arch/arm/mach-pxa/spitz_pm.c:172 spitz_charger_wakeup()
  warn: double left shift '!gpio_get_value(SPITZ_GPIO_KEY_INT)
        << (1 << ((SPITZ_GPIO_KEY_INT) & 31))'

As Dan reported, the value is shifted three times :
 - once by gpio_get_value(), which returns either 0 or BIT(gpio)
 - once by the shift operation '<<'
 - a last time by GPIO_bit(gpio) which is BIT(gpio)

Therefore the calculation lead to a chained or operator of :
 - (1 << gpio) << (1 << gpio) = (2^gpio)^gpio = 2 ^ (gpio * gpio)

It is be sheer luck the former statement works, only because each gpio
used is strictly smaller than 6, and therefore 2^(gpio^2) never
overflows a 32 bits value, and because it is used as a boolean value to
check a gpio activation.

As the xxx_charger_wakeup() functions are used as a true/false detection
mechanism, take that opportunity to change their prototypes from integer
return value to boolean one.

Fixes: 9bf448c66d ("ARM: pxa: use generic gpio operation instead of
gpio register")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
2016-09-09 18:07:59 +02:00

227 lines
6.1 KiB
C

/*
* Battery and Power Management code for the Sharp SL-C7xx
*
* Copyright (c) 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/stat.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/gpio.h>
#include <linux/gpio-pxa.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/apm-emulation.h>
#include <linux/io.h>
#include <asm/irq.h>
#include <asm/mach-types.h>
#include <mach/hardware.h>
#include <mach/corgi.h>
#include <mach/pxa2xx-regs.h>
#include "sharpsl_pm.h"
#include "generic.h"
#define SHARPSL_CHARGE_ON_VOLT 0x99 /* 2.9V */
#define SHARPSL_CHARGE_ON_TEMP 0xe0 /* 2.9V */
#define SHARPSL_CHARGE_ON_ACIN_HIGH 0x9b /* 6V */
#define SHARPSL_CHARGE_ON_ACIN_LOW 0x34 /* 2V */
#define SHARPSL_FATAL_ACIN_VOLT 182 /* 3.45V */
#define SHARPSL_FATAL_NOACIN_VOLT 170 /* 3.40V */
static struct gpio charger_gpios[] = {
{ CORGI_GPIO_ADC_TEMP_ON, GPIOF_OUT_INIT_LOW, "ADC Temp On" },
{ CORGI_GPIO_CHRG_ON, GPIOF_OUT_INIT_LOW, "Charger On" },
{ CORGI_GPIO_CHRG_UKN, GPIOF_OUT_INIT_LOW, "Charger Unknown" },
{ CORGI_GPIO_AC_IN, GPIOF_IN, "Charger Detection" },
{ CORGI_GPIO_KEY_INT, GPIOF_IN, "Key Interrupt" },
{ CORGI_GPIO_WAKEUP, GPIOF_IN, "System wakeup notification" },
};
static void corgi_charger_init(void)
{
gpio_request_array(ARRAY_AND_SIZE(charger_gpios));
}
static void corgi_measure_temp(int on)
{
gpio_set_value(CORGI_GPIO_ADC_TEMP_ON, on);
}
static void corgi_charge(int on)
{
if (on) {
if (machine_is_corgi() && (sharpsl_pm.flags & SHARPSL_SUSPENDED)) {
gpio_set_value(CORGI_GPIO_CHRG_ON, 0);
gpio_set_value(CORGI_GPIO_CHRG_UKN, 1);
} else {
gpio_set_value(CORGI_GPIO_CHRG_ON, 1);
gpio_set_value(CORGI_GPIO_CHRG_UKN, 0);
}
} else {
gpio_set_value(CORGI_GPIO_CHRG_ON, 0);
gpio_set_value(CORGI_GPIO_CHRG_UKN, 0);
}
}
static void corgi_discharge(int on)
{
gpio_set_value(CORGI_GPIO_DISCHARGE_ON, on);
}
static void corgi_presuspend(void)
{
}
static void corgi_postsuspend(void)
{
}
/*
* Check what brought us out of the suspend.
* Return: 0 to sleep, otherwise wake
*/
static int corgi_should_wakeup(unsigned int resume_on_alarm)
{
int is_resume = 0;
dev_dbg(sharpsl_pm.dev, "PEDR = %x, GPIO_AC_IN = %d, "
"GPIO_CHRG_FULL = %d, GPIO_KEY_INT = %d, GPIO_WAKEUP = %d\n",
PEDR, gpio_get_value(CORGI_GPIO_AC_IN),
gpio_get_value(CORGI_GPIO_CHRG_FULL),
gpio_get_value(CORGI_GPIO_KEY_INT),
gpio_get_value(CORGI_GPIO_WAKEUP));
if ((PEDR & GPIO_bit(CORGI_GPIO_AC_IN))) {
if (sharpsl_pm.machinfo->read_devdata(SHARPSL_STATUS_ACIN)) {
/* charge on */
dev_dbg(sharpsl_pm.dev, "ac insert\n");
sharpsl_pm.flags |= SHARPSL_DO_OFFLINE_CHRG;
} else {
/* charge off */
dev_dbg(sharpsl_pm.dev, "ac remove\n");
sharpsl_pm_led(SHARPSL_LED_OFF);
sharpsl_pm.machinfo->charge(0);
sharpsl_pm.charge_mode = CHRG_OFF;
}
}
if ((PEDR & GPIO_bit(CORGI_GPIO_CHRG_FULL)))
dev_dbg(sharpsl_pm.dev, "Charge full interrupt\n");
if (PEDR & GPIO_bit(CORGI_GPIO_KEY_INT))
is_resume |= GPIO_bit(CORGI_GPIO_KEY_INT);
if (PEDR & GPIO_bit(CORGI_GPIO_WAKEUP))
is_resume |= GPIO_bit(CORGI_GPIO_WAKEUP);
if (resume_on_alarm && (PEDR & PWER_RTC))
is_resume |= PWER_RTC;
dev_dbg(sharpsl_pm.dev, "is_resume: %x\n",is_resume);
return is_resume;
}
static bool corgi_charger_wakeup(void)
{
return !gpio_get_value(CORGI_GPIO_AC_IN) ||
!gpio_get_value(CORGI_GPIO_KEY_INT) ||
!gpio_get_value(CORGI_GPIO_WAKEUP);
}
unsigned long corgipm_read_devdata(int type)
{
switch(type) {
case SHARPSL_STATUS_ACIN:
return !gpio_get_value(CORGI_GPIO_AC_IN);
case SHARPSL_STATUS_LOCK:
return gpio_get_value(sharpsl_pm.machinfo->gpio_batlock);
case SHARPSL_STATUS_CHRGFULL:
return gpio_get_value(sharpsl_pm.machinfo->gpio_batfull);
case SHARPSL_STATUS_FATAL:
return gpio_get_value(sharpsl_pm.machinfo->gpio_fatal);
case SHARPSL_ACIN_VOLT:
return sharpsl_pm_pxa_read_max1111(MAX1111_ACIN_VOLT);
case SHARPSL_BATT_TEMP:
return sharpsl_pm_pxa_read_max1111(MAX1111_BATT_TEMP);
case SHARPSL_BATT_VOLT:
default:
return sharpsl_pm_pxa_read_max1111(MAX1111_BATT_VOLT);
}
}
static struct sharpsl_charger_machinfo corgi_pm_machinfo = {
.init = corgi_charger_init,
.exit = NULL,
.gpio_batlock = CORGI_GPIO_BAT_COVER,
.gpio_acin = CORGI_GPIO_AC_IN,
.gpio_batfull = CORGI_GPIO_CHRG_FULL,
.discharge = corgi_discharge,
.charge = corgi_charge,
.measure_temp = corgi_measure_temp,
.presuspend = corgi_presuspend,
.postsuspend = corgi_postsuspend,
.read_devdata = corgipm_read_devdata,
.charger_wakeup = corgi_charger_wakeup,
.should_wakeup = corgi_should_wakeup,
#if defined(CONFIG_LCD_CORGI)
.backlight_limit = corgi_lcd_limit_intensity,
#endif
.charge_on_volt = SHARPSL_CHARGE_ON_VOLT,
.charge_on_temp = SHARPSL_CHARGE_ON_TEMP,
.charge_acin_high = SHARPSL_CHARGE_ON_ACIN_HIGH,
.charge_acin_low = SHARPSL_CHARGE_ON_ACIN_LOW,
.fatal_acin_volt = SHARPSL_FATAL_ACIN_VOLT,
.fatal_noacin_volt= SHARPSL_FATAL_NOACIN_VOLT,
.bat_levels = 40,
.bat_levels_noac = sharpsl_battery_levels_noac,
.bat_levels_acin = sharpsl_battery_levels_acin,
.status_high_acin = 188,
.status_low_acin = 178,
.status_high_noac = 185,
.status_low_noac = 175,
};
static struct platform_device *corgipm_device;
static int corgipm_init(void)
{
int ret;
if (!machine_is_corgi() && !machine_is_shepherd()
&& !machine_is_husky())
return -ENODEV;
corgipm_device = platform_device_alloc("sharpsl-pm", -1);
if (!corgipm_device)
return -ENOMEM;
if (!machine_is_corgi())
corgi_pm_machinfo.batfull_irq = 1;
corgipm_device->dev.platform_data = &corgi_pm_machinfo;
ret = platform_device_add(corgipm_device);
if (ret)
platform_device_put(corgipm_device);
return ret;
}
static void corgipm_exit(void)
{
platform_device_unregister(corgipm_device);
}
module_init(corgipm_init);
module_exit(corgipm_exit);