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linux-next/drivers/hwmon/sht15.c
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from  to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00

702 lines
18 KiB
C

/*
* sht15.c - support for the SHT15 Temperature and Humidity Sensor
*
* Copyright (c) 2009 Jonathan Cameron
*
* Copyright (c) 2007 Wouter Horre
*
* 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.
*
* Currently ignoring checksum on readings.
* Default resolution only (14bit temp, 12bit humidity)
* Ignoring battery status.
* Heater not enabled.
* Timings are all conservative.
*
* Data sheet available (1/2009) at
* http://www.sensirion.ch/en/pdf/product_information/Datasheet-humidity-sensor-SHT1x.pdf
*
* Regulator supply name = vcc
*/
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/gpio.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/err.h>
#include <linux/sht15.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <asm/atomic.h>
#define SHT15_MEASURE_TEMP 3
#define SHT15_MEASURE_RH 5
#define SHT15_READING_NOTHING 0
#define SHT15_READING_TEMP 1
#define SHT15_READING_HUMID 2
/* Min timings in nsecs */
#define SHT15_TSCKL 100 /* clock low */
#define SHT15_TSCKH 100 /* clock high */
#define SHT15_TSU 150 /* data setup time */
/**
* struct sht15_temppair - elements of voltage dependant temp calc
* @vdd: supply voltage in microvolts
* @d1: see data sheet
*/
struct sht15_temppair {
int vdd; /* microvolts */
int d1;
};
/* Table 9 from data sheet - relates temperature calculation
* to supply voltage.
*/
static const struct sht15_temppair temppoints[] = {
{ 2500000, -39400 },
{ 3000000, -39600 },
{ 3500000, -39700 },
{ 4000000, -39800 },
{ 5000000, -40100 },
};
/**
* struct sht15_data - device instance specific data
* @pdata: platform data (gpio's etc)
* @read_work: bh of interrupt handler
* @wait_queue: wait queue for getting values from device
* @val_temp: last temperature value read from device
* @val_humid: last humidity value read from device
* @flag: status flag used to identify what the last request was
* @valid: are the current stored values valid (start condition)
* @last_updat: time of last update
* @read_lock: mutex to ensure only one read in progress
* at a time.
* @dev: associate device structure
* @hwmon_dev: device associated with hwmon subsystem
* @reg: associated regulator (if specified)
* @nb: notifier block to handle notifications of voltage changes
* @supply_uV: local copy of supply voltage used to allow
* use of regulator consumer if available
* @supply_uV_valid: indicates that an updated value has not yet
* been obtained from the regulator and so any calculations
* based upon it will be invalid.
* @update_supply_work: work struct that is used to update the supply_uV
* @interrupt_handled: flag used to indicate a hander has been scheduled
*/
struct sht15_data {
struct sht15_platform_data *pdata;
struct work_struct read_work;
wait_queue_head_t wait_queue;
uint16_t val_temp;
uint16_t val_humid;
u8 flag;
u8 valid;
unsigned long last_updat;
struct mutex read_lock;
struct device *dev;
struct device *hwmon_dev;
struct regulator *reg;
struct notifier_block nb;
int supply_uV;
int supply_uV_valid;
struct work_struct update_supply_work;
atomic_t interrupt_handled;
};
/**
* sht15_connection_reset() - reset the comms interface
* @data: sht15 specific data
*
* This implements section 3.4 of the data sheet
*/
static void sht15_connection_reset(struct sht15_data *data)
{
int i;
gpio_direction_output(data->pdata->gpio_data, 1);
ndelay(SHT15_TSCKL);
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSCKL);
for (i = 0; i < 9; ++i) {
gpio_set_value(data->pdata->gpio_sck, 1);
ndelay(SHT15_TSCKH);
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSCKL);
}
}
/**
* sht15_send_bit() - send an individual bit to the device
* @data: device state data
* @val: value of bit to be sent
**/
static inline void sht15_send_bit(struct sht15_data *data, int val)
{
gpio_set_value(data->pdata->gpio_data, val);
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_sck, 1);
ndelay(SHT15_TSCKH);
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSCKL); /* clock low time */
}
/**
* sht15_transmission_start() - specific sequence for new transmission
*
* @data: device state data
* Timings for this are not documented on the data sheet, so very
* conservative ones used in implementation. This implements
* figure 12 on the data sheet.
**/
static void sht15_transmission_start(struct sht15_data *data)
{
/* ensure data is high and output */
gpio_direction_output(data->pdata->gpio_data, 1);
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSCKL);
gpio_set_value(data->pdata->gpio_sck, 1);
ndelay(SHT15_TSCKH);
gpio_set_value(data->pdata->gpio_data, 0);
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSCKL);
gpio_set_value(data->pdata->gpio_sck, 1);
ndelay(SHT15_TSCKH);
gpio_set_value(data->pdata->gpio_data, 1);
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSCKL);
}
/**
* sht15_send_byte() - send a single byte to the device
* @data: device state
* @byte: value to be sent
**/
static void sht15_send_byte(struct sht15_data *data, u8 byte)
{
int i;
for (i = 0; i < 8; i++) {
sht15_send_bit(data, !!(byte & 0x80));
byte <<= 1;
}
}
/**
* sht15_wait_for_response() - checks for ack from device
* @data: device state
**/
static int sht15_wait_for_response(struct sht15_data *data)
{
gpio_direction_input(data->pdata->gpio_data);
gpio_set_value(data->pdata->gpio_sck, 1);
ndelay(SHT15_TSCKH);
if (gpio_get_value(data->pdata->gpio_data)) {
gpio_set_value(data->pdata->gpio_sck, 0);
dev_err(data->dev, "Command not acknowledged\n");
sht15_connection_reset(data);
return -EIO;
}
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSCKL);
return 0;
}
/**
* sht15_send_cmd() - Sends a command to the device.
* @data: device state
* @cmd: command byte to be sent
*
* On entry, sck is output low, data is output pull high
* and the interrupt disabled.
**/
static int sht15_send_cmd(struct sht15_data *data, u8 cmd)
{
int ret = 0;
sht15_transmission_start(data);
sht15_send_byte(data, cmd);
ret = sht15_wait_for_response(data);
return ret;
}
/**
* sht15_update_single_val() - get a new value from device
* @data: device instance specific data
* @command: command sent to request value
* @timeout_msecs: timeout after which comms are assumed
* to have failed are reset.
**/
static inline int sht15_update_single_val(struct sht15_data *data,
int command,
int timeout_msecs)
{
int ret;
ret = sht15_send_cmd(data, command);
if (ret)
return ret;
gpio_direction_input(data->pdata->gpio_data);
atomic_set(&data->interrupt_handled, 0);
enable_irq(gpio_to_irq(data->pdata->gpio_data));
if (gpio_get_value(data->pdata->gpio_data) == 0) {
disable_irq_nosync(gpio_to_irq(data->pdata->gpio_data));
/* Only relevant if the interrupt hasn't occured. */
if (!atomic_read(&data->interrupt_handled))
schedule_work(&data->read_work);
}
ret = wait_event_timeout(data->wait_queue,
(data->flag == SHT15_READING_NOTHING),
msecs_to_jiffies(timeout_msecs));
if (ret == 0) {/* timeout occurred */
disable_irq_nosync(gpio_to_irq(data->pdata->gpio_data));
sht15_connection_reset(data);
return -ETIME;
}
return 0;
}
/**
* sht15_update_vals() - get updated readings from device if too old
* @data: device state
**/
static int sht15_update_vals(struct sht15_data *data)
{
int ret = 0;
int timeout = HZ;
mutex_lock(&data->read_lock);
if (time_after(jiffies, data->last_updat + timeout)
|| !data->valid) {
data->flag = SHT15_READING_HUMID;
ret = sht15_update_single_val(data, SHT15_MEASURE_RH, 160);
if (ret)
goto error_ret;
data->flag = SHT15_READING_TEMP;
ret = sht15_update_single_val(data, SHT15_MEASURE_TEMP, 400);
if (ret)
goto error_ret;
data->valid = 1;
data->last_updat = jiffies;
}
error_ret:
mutex_unlock(&data->read_lock);
return ret;
}
/**
* sht15_calc_temp() - convert the raw reading to a temperature
* @data: device state
*
* As per section 4.3 of the data sheet.
**/
static inline int sht15_calc_temp(struct sht15_data *data)
{
int d1 = 0;
int i;
for (i = 1; i < ARRAY_SIZE(temppoints); i++)
/* Find pointer to interpolate */
if (data->supply_uV > temppoints[i - 1].vdd) {
d1 = (data->supply_uV/1000 - temppoints[i - 1].vdd)
* (temppoints[i].d1 - temppoints[i - 1].d1)
/ (temppoints[i].vdd - temppoints[i - 1].vdd)
+ temppoints[i - 1].d1;
break;
}
return data->val_temp*10 + d1;
}
/**
* sht15_calc_humid() - using last temperature convert raw to humid
* @data: device state
*
* This is the temperature compensated version as per section 4.2 of
* the data sheet.
**/
static inline int sht15_calc_humid(struct sht15_data *data)
{
int RHlinear; /* milli percent */
int temp = sht15_calc_temp(data);
const int c1 = -4;
const int c2 = 40500; /* x 10 ^ -6 */
const int c3 = -2800; /* x10 ^ -9 */
RHlinear = c1*1000
+ c2 * data->val_humid/1000
+ (data->val_humid * data->val_humid * c3)/1000000;
return (temp - 25000) * (10000 + 80 * data->val_humid)
/ 1000000 + RHlinear;
}
static ssize_t sht15_show_temp(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int ret;
struct sht15_data *data = dev_get_drvdata(dev);
/* Technically no need to read humidity as well */
ret = sht15_update_vals(data);
return ret ? ret : sprintf(buf, "%d\n",
sht15_calc_temp(data));
}
static ssize_t sht15_show_humidity(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int ret;
struct sht15_data *data = dev_get_drvdata(dev);
ret = sht15_update_vals(data);
return ret ? ret : sprintf(buf, "%d\n", sht15_calc_humid(data));
};
static ssize_t show_name(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct platform_device *pdev = to_platform_device(dev);
return sprintf(buf, "%s\n", pdev->name);
}
static SENSOR_DEVICE_ATTR(temp1_input,
S_IRUGO, sht15_show_temp,
NULL, 0);
static SENSOR_DEVICE_ATTR(humidity1_input,
S_IRUGO, sht15_show_humidity,
NULL, 0);
static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
static struct attribute *sht15_attrs[] = {
&sensor_dev_attr_temp1_input.dev_attr.attr,
&sensor_dev_attr_humidity1_input.dev_attr.attr,
&dev_attr_name.attr,
NULL,
};
static const struct attribute_group sht15_attr_group = {
.attrs = sht15_attrs,
};
static irqreturn_t sht15_interrupt_fired(int irq, void *d)
{
struct sht15_data *data = d;
/* First disable the interrupt */
disable_irq_nosync(irq);
atomic_inc(&data->interrupt_handled);
/* Then schedule a reading work struct */
if (data->flag != SHT15_READING_NOTHING)
schedule_work(&data->read_work);
return IRQ_HANDLED;
}
/* Each byte of data is acknowledged by pulling the data line
* low for one clock pulse.
*/
static void sht15_ack(struct sht15_data *data)
{
gpio_direction_output(data->pdata->gpio_data, 0);
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_sck, 1);
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_data, 1);
gpio_direction_input(data->pdata->gpio_data);
}
/**
* sht15_end_transmission() - notify device of end of transmission
* @data: device state
*
* This is basically a NAK. (single clock pulse, data high)
**/
static void sht15_end_transmission(struct sht15_data *data)
{
gpio_direction_output(data->pdata->gpio_data, 1);
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_sck, 1);
ndelay(SHT15_TSCKH);
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSCKL);
}
static void sht15_bh_read_data(struct work_struct *work_s)
{
int i;
uint16_t val = 0;
struct sht15_data *data
= container_of(work_s, struct sht15_data,
read_work);
/* Firstly, verify the line is low */
if (gpio_get_value(data->pdata->gpio_data)) {
/* If not, then start the interrupt again - care
here as could have gone low in meantime so verify
it hasn't!
*/
atomic_set(&data->interrupt_handled, 0);
enable_irq(gpio_to_irq(data->pdata->gpio_data));
/* If still not occured or another handler has been scheduled */
if (gpio_get_value(data->pdata->gpio_data)
|| atomic_read(&data->interrupt_handled))
return;
}
/* Read the data back from the device */
for (i = 0; i < 16; ++i) {
val <<= 1;
gpio_set_value(data->pdata->gpio_sck, 1);
ndelay(SHT15_TSCKH);
val |= !!gpio_get_value(data->pdata->gpio_data);
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSCKL);
if (i == 7)
sht15_ack(data);
}
/* Tell the device we are done */
sht15_end_transmission(data);
switch (data->flag) {
case SHT15_READING_TEMP:
data->val_temp = val;
break;
case SHT15_READING_HUMID:
data->val_humid = val;
break;
}
data->flag = SHT15_READING_NOTHING;
wake_up(&data->wait_queue);
}
static void sht15_update_voltage(struct work_struct *work_s)
{
struct sht15_data *data
= container_of(work_s, struct sht15_data,
update_supply_work);
data->supply_uV = regulator_get_voltage(data->reg);
}
/**
* sht15_invalidate_voltage() - mark supply voltage invalid when notified by reg
* @nb: associated notification structure
* @event: voltage regulator state change event code
* @ignored: function parameter - ignored here
*
* Note that as the notification code holds the regulator lock, we have
* to schedule an update of the supply voltage rather than getting it directly.
**/
static int sht15_invalidate_voltage(struct notifier_block *nb,
unsigned long event,
void *ignored)
{
struct sht15_data *data = container_of(nb, struct sht15_data, nb);
if (event == REGULATOR_EVENT_VOLTAGE_CHANGE)
data->supply_uV_valid = false;
schedule_work(&data->update_supply_work);
return NOTIFY_OK;
}
static int __devinit sht15_probe(struct platform_device *pdev)
{
int ret = 0;
struct sht15_data *data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data) {
ret = -ENOMEM;
dev_err(&pdev->dev, "kzalloc failed");
goto error_ret;
}
INIT_WORK(&data->read_work, sht15_bh_read_data);
INIT_WORK(&data->update_supply_work, sht15_update_voltage);
platform_set_drvdata(pdev, data);
mutex_init(&data->read_lock);
data->dev = &pdev->dev;
init_waitqueue_head(&data->wait_queue);
if (pdev->dev.platform_data == NULL) {
dev_err(&pdev->dev, "no platform data supplied");
goto err_free_data;
}
data->pdata = pdev->dev.platform_data;
data->supply_uV = data->pdata->supply_mv*1000;
/* If a regulator is available, query what the supply voltage actually is!*/
data->reg = regulator_get(data->dev, "vcc");
if (!IS_ERR(data->reg)) {
data->supply_uV = regulator_get_voltage(data->reg);
regulator_enable(data->reg);
/* setup a notifier block to update this if another device
* causes the voltage to change */
data->nb.notifier_call = &sht15_invalidate_voltage;
ret = regulator_register_notifier(data->reg, &data->nb);
}
/* Try requesting the GPIOs */
ret = gpio_request(data->pdata->gpio_sck, "SHT15 sck");
if (ret) {
dev_err(&pdev->dev, "gpio request failed");
goto err_free_data;
}
gpio_direction_output(data->pdata->gpio_sck, 0);
ret = gpio_request(data->pdata->gpio_data, "SHT15 data");
if (ret) {
dev_err(&pdev->dev, "gpio request failed");
goto err_release_gpio_sck;
}
ret = sysfs_create_group(&pdev->dev.kobj, &sht15_attr_group);
if (ret) {
dev_err(&pdev->dev, "sysfs create failed");
goto err_release_gpio_data;
}
ret = request_irq(gpio_to_irq(data->pdata->gpio_data),
sht15_interrupt_fired,
IRQF_TRIGGER_FALLING,
"sht15 data",
data);
if (ret) {
dev_err(&pdev->dev, "failed to get irq for data line");
goto err_release_gpio_data;
}
disable_irq_nosync(gpio_to_irq(data->pdata->gpio_data));
sht15_connection_reset(data);
sht15_send_cmd(data, 0x1E);
data->hwmon_dev = hwmon_device_register(data->dev);
if (IS_ERR(data->hwmon_dev)) {
ret = PTR_ERR(data->hwmon_dev);
goto err_release_irq;
}
return 0;
err_release_irq:
free_irq(gpio_to_irq(data->pdata->gpio_data), data);
err_release_gpio_data:
gpio_free(data->pdata->gpio_data);
err_release_gpio_sck:
gpio_free(data->pdata->gpio_sck);
err_free_data:
kfree(data);
error_ret:
return ret;
}
static int __devexit sht15_remove(struct platform_device *pdev)
{
struct sht15_data *data = platform_get_drvdata(pdev);
/* Make sure any reads from the device are done and
* prevent new ones beginnning */
mutex_lock(&data->read_lock);
hwmon_device_unregister(data->hwmon_dev);
sysfs_remove_group(&pdev->dev.kobj, &sht15_attr_group);
if (!IS_ERR(data->reg)) {
regulator_unregister_notifier(data->reg, &data->nb);
regulator_disable(data->reg);
regulator_put(data->reg);
}
free_irq(gpio_to_irq(data->pdata->gpio_data), data);
gpio_free(data->pdata->gpio_data);
gpio_free(data->pdata->gpio_sck);
mutex_unlock(&data->read_lock);
kfree(data);
return 0;
}
/*
* sht_drivers simultaneously refers to __devinit and __devexit function
* which causes spurious section mismatch warning. So use __refdata to
* get rid from this.
*/
static struct platform_driver __refdata sht_drivers[] = {
{
.driver = {
.name = "sht10",
.owner = THIS_MODULE,
},
.probe = sht15_probe,
.remove = __devexit_p(sht15_remove),
}, {
.driver = {
.name = "sht11",
.owner = THIS_MODULE,
},
.probe = sht15_probe,
.remove = __devexit_p(sht15_remove),
}, {
.driver = {
.name = "sht15",
.owner = THIS_MODULE,
},
.probe = sht15_probe,
.remove = __devexit_p(sht15_remove),
}, {
.driver = {
.name = "sht71",
.owner = THIS_MODULE,
},
.probe = sht15_probe,
.remove = __devexit_p(sht15_remove),
}, {
.driver = {
.name = "sht75",
.owner = THIS_MODULE,
},
.probe = sht15_probe,
.remove = __devexit_p(sht15_remove),
},
};
static int __init sht15_init(void)
{
int ret;
int i;
for (i = 0; i < ARRAY_SIZE(sht_drivers); i++) {
ret = platform_driver_register(&sht_drivers[i]);
if (ret)
goto error_unreg;
}
return 0;
error_unreg:
while (--i >= 0)
platform_driver_unregister(&sht_drivers[i]);
return ret;
}
module_init(sht15_init);
static void __exit sht15_exit(void)
{
int i;
for (i = ARRAY_SIZE(sht_drivers) - 1; i >= 0; i--)
platform_driver_unregister(&sht_drivers[i]);
}
module_exit(sht15_exit);
MODULE_LICENSE("GPL");