linux/drivers/leds/leds-lp3944.c

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/*
* leds-lp3944.c - driver for National Semiconductor LP3944 Funlight Chip
*
* Copyright (C) 2009 Antonio Ospite <ospite@studenti.unina.it>
*
* 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.
*
*/
/*
* I2C driver for National Semiconductor LP3944 Funlight Chip
* http://www.national.com/pf/LP/LP3944.html
*
* This helper chip can drive up to 8 leds, with two programmable DIM modes;
* it could even be used as a gpio expander but this driver assumes it is used
* as a led controller.
*
* The DIM modes are used to set _blink_ patterns for leds, the pattern is
* specified supplying two parameters:
* - period: from 0s to 1.6s
* - duty cycle: percentage of the period the led is on, from 0 to 100
*
* LP3944 can be found on Motorola A910 smartphone, where it drives the rgb
* leds, the camera flash light and the displays backlights.
*/
#include <linux/module.h>
#include <linux/i2c.h>
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 #2 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>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/leds.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include <linux/leds-lp3944.h>
/* Read Only Registers */
#define LP3944_REG_INPUT1 0x00 /* LEDs 0-7 InputRegister (Read Only) */
#define LP3944_REG_REGISTER1 0x01 /* None (Read Only) */
#define LP3944_REG_PSC0 0x02 /* Frequency Prescaler 0 (R/W) */
#define LP3944_REG_PWM0 0x03 /* PWM Register 0 (R/W) */
#define LP3944_REG_PSC1 0x04 /* Frequency Prescaler 1 (R/W) */
#define LP3944_REG_PWM1 0x05 /* PWM Register 1 (R/W) */
#define LP3944_REG_LS0 0x06 /* LEDs 0-3 Selector (R/W) */
#define LP3944_REG_LS1 0x07 /* LEDs 4-7 Selector (R/W) */
/* These registers are not used to control leds in LP3944, they can store
* arbitrary values which the chip will ignore.
*/
#define LP3944_REG_REGISTER8 0x08
#define LP3944_REG_REGISTER9 0x09
#define LP3944_DIM0 0
#define LP3944_DIM1 1
/* period in ms */
#define LP3944_PERIOD_MIN 0
#define LP3944_PERIOD_MAX 1600
/* duty cycle is a percentage */
#define LP3944_DUTY_CYCLE_MIN 0
#define LP3944_DUTY_CYCLE_MAX 100
#define ldev_to_led(c) container_of(c, struct lp3944_led_data, ldev)
/* Saved data */
struct lp3944_led_data {
u8 id;
enum lp3944_type type;
enum lp3944_status status;
struct led_classdev ldev;
struct i2c_client *client;
struct work_struct work;
};
struct lp3944_data {
struct mutex lock;
struct i2c_client *client;
struct lp3944_led_data leds[LP3944_LEDS_MAX];
};
static int lp3944_reg_read(struct i2c_client *client, u8 reg, u8 *value)
{
int tmp;
tmp = i2c_smbus_read_byte_data(client, reg);
if (tmp < 0)
return -EINVAL;
*value = tmp;
return 0;
}
static int lp3944_reg_write(struct i2c_client *client, u8 reg, u8 value)
{
return i2c_smbus_write_byte_data(client, reg, value);
}
/**
* Set the period for DIM status
*
* @client: the i2c client
* @dim: either LP3944_DIM0 or LP3944_DIM1
* @period: period of a blink, that is a on/off cycle, expressed in ms.
*/
static int lp3944_dim_set_period(struct i2c_client *client, u8 dim, u16 period)
{
u8 psc_reg;
u8 psc_value;
int err;
if (dim == LP3944_DIM0)
psc_reg = LP3944_REG_PSC0;
else if (dim == LP3944_DIM1)
psc_reg = LP3944_REG_PSC1;
else
return -EINVAL;
/* Convert period to Prescaler value */
if (period > LP3944_PERIOD_MAX)
return -EINVAL;
psc_value = (period * 255) / LP3944_PERIOD_MAX;
err = lp3944_reg_write(client, psc_reg, psc_value);
return err;
}
/**
* Set the duty cycle for DIM status
*
* @client: the i2c client
* @dim: either LP3944_DIM0 or LP3944_DIM1
* @duty_cycle: percentage of a period during which a led is ON
*/
static int lp3944_dim_set_dutycycle(struct i2c_client *client, u8 dim,
u8 duty_cycle)
{
u8 pwm_reg;
u8 pwm_value;
int err;
if (dim == LP3944_DIM0)
pwm_reg = LP3944_REG_PWM0;
else if (dim == LP3944_DIM1)
pwm_reg = LP3944_REG_PWM1;
else
return -EINVAL;
/* Convert duty cycle to PWM value */
if (duty_cycle > LP3944_DUTY_CYCLE_MAX)
return -EINVAL;
pwm_value = (duty_cycle * 255) / LP3944_DUTY_CYCLE_MAX;
err = lp3944_reg_write(client, pwm_reg, pwm_value);
return err;
}
/**
* Set the led status
*
* @led: a lp3944_led_data structure
* @status: one of LP3944_LED_STATUS_OFF
* LP3944_LED_STATUS_ON
* LP3944_LED_STATUS_DIM0
* LP3944_LED_STATUS_DIM1
*/
static int lp3944_led_set(struct lp3944_led_data *led, u8 status)
{
struct lp3944_data *data = i2c_get_clientdata(led->client);
u8 id = led->id;
u8 reg;
u8 val = 0;
int err;
dev_dbg(&led->client->dev, "%s: %s, status before normalization:%d\n",
__func__, led->ldev.name, status);
switch (id) {
case LP3944_LED0:
case LP3944_LED1:
case LP3944_LED2:
case LP3944_LED3:
reg = LP3944_REG_LS0;
break;
case LP3944_LED4:
case LP3944_LED5:
case LP3944_LED6:
case LP3944_LED7:
id -= LP3944_LED4;
reg = LP3944_REG_LS1;
break;
default:
return -EINVAL;
}
if (status > LP3944_LED_STATUS_DIM1)
return -EINVAL;
/* invert only 0 and 1, leave unchanged the other values,
* remember we are abusing status to set blink patterns
*/
if (led->type == LP3944_LED_TYPE_LED_INVERTED && status < 2)
status = 1 - status;
mutex_lock(&data->lock);
lp3944_reg_read(led->client, reg, &val);
val &= ~(LP3944_LED_STATUS_MASK << (id << 1));
val |= (status << (id << 1));
dev_dbg(&led->client->dev, "%s: %s, reg:%d id:%d status:%d val:%#x\n",
__func__, led->ldev.name, reg, id, status, val);
/* set led status */
err = lp3944_reg_write(led->client, reg, val);
mutex_unlock(&data->lock);
return err;
}
static int lp3944_led_set_blink(struct led_classdev *led_cdev,
unsigned long *delay_on,
unsigned long *delay_off)
{
struct lp3944_led_data *led = ldev_to_led(led_cdev);
u16 period;
u8 duty_cycle;
int err;
/* units are in ms */
if (*delay_on + *delay_off > LP3944_PERIOD_MAX)
return -EINVAL;
if (*delay_on == 0 && *delay_off == 0) {
/* Special case: the leds subsystem requires a default user
* friendly blink pattern for the LED. Let's blink the led
* slowly (1Hz).
*/
*delay_on = 500;
*delay_off = 500;
}
period = (*delay_on) + (*delay_off);
/* duty_cycle is the percentage of period during which the led is ON */
duty_cycle = 100 * (*delay_on) / period;
/* invert duty cycle for inverted leds, this has the same effect of
* swapping delay_on and delay_off
*/
if (led->type == LP3944_LED_TYPE_LED_INVERTED)
duty_cycle = 100 - duty_cycle;
/* NOTE: using always the first DIM mode, this means that all leds
* will have the same blinking pattern.
*
* We could find a way later to have two leds blinking in hardware
* with different patterns at the same time, falling back to software
* control for the other ones.
*/
err = lp3944_dim_set_period(led->client, LP3944_DIM0, period);
if (err)
return err;
err = lp3944_dim_set_dutycycle(led->client, LP3944_DIM0, duty_cycle);
if (err)
return err;
dev_dbg(&led->client->dev, "%s: OK hardware accelerated blink!\n",
__func__);
led->status = LP3944_LED_STATUS_DIM0;
schedule_work(&led->work);
return 0;
}
static void lp3944_led_set_brightness(struct led_classdev *led_cdev,
enum led_brightness brightness)
{
struct lp3944_led_data *led = ldev_to_led(led_cdev);
dev_dbg(&led->client->dev, "%s: %s, %d\n",
__func__, led_cdev->name, brightness);
led->status = brightness;
schedule_work(&led->work);
}
static void lp3944_led_work(struct work_struct *work)
{
struct lp3944_led_data *led;
led = container_of(work, struct lp3944_led_data, work);
lp3944_led_set(led, led->status);
}
static int lp3944_configure(struct i2c_client *client,
struct lp3944_data *data,
struct lp3944_platform_data *pdata)
{
int i, err = 0;
for (i = 0; i < pdata->leds_size; i++) {
struct lp3944_led *pled = &pdata->leds[i];
struct lp3944_led_data *led = &data->leds[i];
led->client = client;
led->id = i;
switch (pled->type) {
case LP3944_LED_TYPE_LED:
case LP3944_LED_TYPE_LED_INVERTED:
led->type = pled->type;
led->status = pled->status;
led->ldev.name = pled->name;
led->ldev.max_brightness = 1;
led->ldev.brightness_set = lp3944_led_set_brightness;
led->ldev.blink_set = lp3944_led_set_blink;
led->ldev.flags = LED_CORE_SUSPENDRESUME;
INIT_WORK(&led->work, lp3944_led_work);
err = led_classdev_register(&client->dev, &led->ldev);
if (err < 0) {
dev_err(&client->dev,
"couldn't register LED %s\n",
led->ldev.name);
goto exit;
}
/* to expose the default value to userspace */
led->ldev.brightness = led->status;
/* Set the default led status */
err = lp3944_led_set(led, led->status);
if (err < 0) {
dev_err(&client->dev,
"%s couldn't set STATUS %d\n",
led->ldev.name, led->status);
goto exit;
}
break;
case LP3944_LED_TYPE_NONE:
default:
break;
}
}
return 0;
exit:
if (i > 0)
for (i = i - 1; i >= 0; i--)
switch (pdata->leds[i].type) {
case LP3944_LED_TYPE_LED:
case LP3944_LED_TYPE_LED_INVERTED:
led_classdev_unregister(&data->leds[i].ldev);
cancel_work_sync(&data->leds[i].work);
break;
case LP3944_LED_TYPE_NONE:
default:
break;
}
return err;
}
static int lp3944_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct lp3944_platform_data *lp3944_pdata = client->dev.platform_data;
struct lp3944_data *data;
int err;
if (lp3944_pdata == NULL) {
dev_err(&client->dev, "no platform data\n");
return -EINVAL;
}
/* Let's see whether this adapter can support what we need. */
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_BYTE_DATA)) {
dev_err(&client->dev, "insufficient functionality!\n");
return -ENODEV;
}
data = devm_kzalloc(&client->dev, sizeof(struct lp3944_data),
GFP_KERNEL);
if (!data)
return -ENOMEM;
data->client = client;
i2c_set_clientdata(client, data);
mutex_init(&data->lock);
err = lp3944_configure(client, data, lp3944_pdata);
if (err < 0)
return err;
dev_info(&client->dev, "lp3944 enabled\n");
return 0;
}
static int lp3944_remove(struct i2c_client *client)
{
struct lp3944_platform_data *pdata = client->dev.platform_data;
struct lp3944_data *data = i2c_get_clientdata(client);
int i;
for (i = 0; i < pdata->leds_size; i++)
switch (data->leds[i].type) {
case LP3944_LED_TYPE_LED:
case LP3944_LED_TYPE_LED_INVERTED:
led_classdev_unregister(&data->leds[i].ldev);
cancel_work_sync(&data->leds[i].work);
break;
case LP3944_LED_TYPE_NONE:
default:
break;
}
return 0;
}
/* lp3944 i2c driver struct */
static const struct i2c_device_id lp3944_id[] = {
{"lp3944", 0},
{}
};
MODULE_DEVICE_TABLE(i2c, lp3944_id);
static struct i2c_driver lp3944_driver = {
.driver = {
.name = "lp3944",
},
.probe = lp3944_probe,
.remove = lp3944_remove,
.id_table = lp3944_id,
};
module_i2c_driver(lp3944_driver);
MODULE_AUTHOR("Antonio Ospite <ospite@studenti.unina.it>");
MODULE_DESCRIPTION("LP3944 Fun Light Chip");
MODULE_LICENSE("GPL");