linux/drivers/leds/leds-pca955x.c

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/*
* Copyright 2007-2008 Extreme Engineering Solutions, Inc.
*
* Author: Nate Case <ncase@xes-inc.com>
*
* This file is subject to the terms and conditions of version 2 of
* the GNU General Public License. See the file COPYING in the main
* directory of this archive for more details.
*
* LED driver for various PCA955x I2C LED drivers
*
* Supported devices:
*
* Device Description 7-bit slave address
* ------ ----------- -------------------
* PCA9550 2-bit driver 0x60 .. 0x61
* PCA9551 8-bit driver 0x60 .. 0x67
* PCA9552 16-bit driver 0x60 .. 0x67
* PCA9553/01 4-bit driver 0x62
* PCA9553/02 4-bit driver 0x63
*
* Philips PCA955x LED driver chips follow a register map as shown below:
*
* Control Register Description
* ---------------- -----------
* 0x0 Input register 0
* ..
* NUM_INPUT_REGS - 1 Last Input register X
*
* NUM_INPUT_REGS Frequency prescaler 0
* NUM_INPUT_REGS + 1 PWM register 0
* NUM_INPUT_REGS + 2 Frequency prescaler 1
* NUM_INPUT_REGS + 3 PWM register 1
*
* NUM_INPUT_REGS + 4 LED selector 0
* NUM_INPUT_REGS + 4
* + NUM_LED_REGS - 1 Last LED selector
*
* where NUM_INPUT_REGS and NUM_LED_REGS vary depending on how many
* bits the chip supports.
*/
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/leds.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/workqueue.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>
/* LED select registers determine the source that drives LED outputs */
#define PCA955X_LS_LED_ON 0x0 /* Output LOW */
#define PCA955X_LS_LED_OFF 0x1 /* Output HI-Z */
#define PCA955X_LS_BLINK0 0x2 /* Blink at PWM0 rate */
#define PCA955X_LS_BLINK1 0x3 /* Blink at PWM1 rate */
enum pca955x_type {
pca9550,
pca9551,
pca9552,
pca9553,
};
struct pca955x_chipdef {
int bits;
u8 slv_addr; /* 7-bit slave address mask */
int slv_addr_shift; /* Number of bits to ignore */
};
static struct pca955x_chipdef pca955x_chipdefs[] = {
[pca9550] = {
.bits = 2,
.slv_addr = /* 110000x */ 0x60,
.slv_addr_shift = 1,
},
[pca9551] = {
.bits = 8,
.slv_addr = /* 1100xxx */ 0x60,
.slv_addr_shift = 3,
},
[pca9552] = {
.bits = 16,
.slv_addr = /* 1100xxx */ 0x60,
.slv_addr_shift = 3,
},
[pca9553] = {
.bits = 4,
.slv_addr = /* 110001x */ 0x62,
.slv_addr_shift = 1,
},
};
static const struct i2c_device_id pca955x_id[] = {
{ "pca9550", pca9550 },
{ "pca9551", pca9551 },
{ "pca9552", pca9552 },
{ "pca9553", pca9553 },
{ }
};
MODULE_DEVICE_TABLE(i2c, pca955x_id);
struct pca955x {
struct mutex lock;
struct pca955x_led *leds;
struct pca955x_chipdef *chipdef;
struct i2c_client *client;
};
struct pca955x_led {
struct pca955x *pca955x;
struct work_struct work;
enum led_brightness brightness;
struct led_classdev led_cdev;
int led_num; /* 0 .. 15 potentially */
char name[32];
};
/* 8 bits per input register */
static inline int pca95xx_num_input_regs(int bits)
{
return (bits + 7) / 8;
}
/* 4 bits per LED selector register */
static inline int pca95xx_num_led_regs(int bits)
{
return (bits + 3) / 4;
}
/*
* Return an LED selector register value based on an existing one, with
* the appropriate 2-bit state value set for the given LED number (0-3).
*/
static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state)
{
return (oldval & (~(0x3 << (led_num << 1)))) |
((state & 0x3) << (led_num << 1));
}
/*
* Write to frequency prescaler register, used to program the
* period of the PWM output. period = (PSCx + 1) / 38
*/
static void pca955x_write_psc(struct i2c_client *client, int n, u8 val)
{
struct pca955x *pca955x = i2c_get_clientdata(client);
i2c_smbus_write_byte_data(client,
pca95xx_num_input_regs(pca955x->chipdef->bits) + 2*n,
val);
}
/*
* Write to PWM register, which determines the duty cycle of the
* output. LED is OFF when the count is less than the value of this
* register, and ON when it is greater. If PWMx == 0, LED is always OFF.
*
* Duty cycle is (256 - PWMx) / 256
*/
static void pca955x_write_pwm(struct i2c_client *client, int n, u8 val)
{
struct pca955x *pca955x = i2c_get_clientdata(client);
i2c_smbus_write_byte_data(client,
pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + 2*n,
val);
}
/*
* Write to LED selector register, which determines the source that
* drives the LED output.
*/
static void pca955x_write_ls(struct i2c_client *client, int n, u8 val)
{
struct pca955x *pca955x = i2c_get_clientdata(client);
i2c_smbus_write_byte_data(client,
pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n,
val);
}
/*
* Read the LED selector register, which determines the source that
* drives the LED output.
*/
static u8 pca955x_read_ls(struct i2c_client *client, int n)
{
struct pca955x *pca955x = i2c_get_clientdata(client);
return (u8) i2c_smbus_read_byte_data(client,
pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n);
}
static void pca955x_led_work(struct work_struct *work)
{
struct pca955x_led *pca955x_led;
struct pca955x *pca955x;
u8 ls;
int chip_ls; /* which LSx to use (0-3 potentially) */
int ls_led; /* which set of bits within LSx to use (0-3) */
pca955x_led = container_of(work, struct pca955x_led, work);
pca955x = pca955x_led->pca955x;
chip_ls = pca955x_led->led_num / 4;
ls_led = pca955x_led->led_num % 4;
mutex_lock(&pca955x->lock);
ls = pca955x_read_ls(pca955x->client, chip_ls);
switch (pca955x_led->brightness) {
case LED_FULL:
ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON);
break;
case LED_OFF:
ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF);
break;
case LED_HALF:
ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0);
break;
default:
/*
* Use PWM1 for all other values. This has the unwanted
* side effect of making all LEDs on the chip share the
* same brightness level if set to a value other than
* OFF, HALF, or FULL. But, this is probably better than
* just turning off for all other values.
*/
pca955x_write_pwm(pca955x->client, 1,
255 - pca955x_led->brightness);
ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1);
break;
}
pca955x_write_ls(pca955x->client, chip_ls, ls);
mutex_unlock(&pca955x->lock);
}
static void pca955x_led_set(struct led_classdev *led_cdev, enum led_brightness value)
{
struct pca955x_led *pca955x;
pca955x = container_of(led_cdev, struct pca955x_led, led_cdev);
pca955x->brightness = value;
/*
* Must use workqueue for the actual I/O since I2C operations
* can sleep.
*/
schedule_work(&pca955x->work);
}
static int __devinit pca955x_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct pca955x *pca955x;
struct pca955x_led *pca955x_led;
struct pca955x_chipdef *chip;
struct i2c_adapter *adapter;
struct led_platform_data *pdata;
int i, err;
chip = &pca955x_chipdefs[id->driver_data];
adapter = to_i2c_adapter(client->dev.parent);
pdata = client->dev.platform_data;
/* Make sure the slave address / chip type combo given is possible */
if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) !=
chip->slv_addr) {
dev_err(&client->dev, "invalid slave address %02x\n",
client->addr);
return -ENODEV;
}
printk(KERN_INFO "leds-pca955x: Using %s %d-bit LED driver at "
"slave address 0x%02x\n",
id->name, chip->bits, client->addr);
if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
return -EIO;
if (pdata) {
if (pdata->num_leds != chip->bits) {
dev_err(&client->dev, "board info claims %d LEDs"
" on a %d-bit chip\n",
pdata->num_leds, chip->bits);
return -ENODEV;
}
}
pca955x = kzalloc(sizeof(*pca955x), GFP_KERNEL);
if (!pca955x)
return -ENOMEM;
pca955x->leds = kzalloc(sizeof(*pca955x_led) * chip->bits, GFP_KERNEL);
if (!pca955x->leds) {
err = -ENOMEM;
goto exit_nomem;
}
i2c_set_clientdata(client, pca955x);
mutex_init(&pca955x->lock);
pca955x->client = client;
pca955x->chipdef = chip;
for (i = 0; i < chip->bits; i++) {
pca955x_led = &pca955x->leds[i];
pca955x_led->led_num = i;
pca955x_led->pca955x = pca955x;
/* Platform data can specify LED names and default triggers */
if (pdata) {
if (pdata->leds[i].name)
snprintf(pca955x_led->name,
sizeof(pca955x_led->name), "pca955x:%s",
pdata->leds[i].name);
if (pdata->leds[i].default_trigger)
pca955x_led->led_cdev.default_trigger =
pdata->leds[i].default_trigger;
} else {
snprintf(pca955x_led->name, sizeof(pca955x_led->name),
"pca955x:%d", i);
}
pca955x_led->led_cdev.name = pca955x_led->name;
pca955x_led->led_cdev.brightness_set = pca955x_led_set;
INIT_WORK(&pca955x_led->work, pca955x_led_work);
err = led_classdev_register(&client->dev,
&pca955x_led->led_cdev);
if (err < 0)
goto exit;
}
/* Turn off LEDs */
for (i = 0; i < pca95xx_num_led_regs(chip->bits); i++)
pca955x_write_ls(client, i, 0x55);
/* PWM0 is used for half brightness or 50% duty cycle */
pca955x_write_pwm(client, 0, 255-LED_HALF);
/* PWM1 is used for variable brightness, default to OFF */
pca955x_write_pwm(client, 1, 0);
/* Set to fast frequency so we do not see flashing */
pca955x_write_psc(client, 0, 0);
pca955x_write_psc(client, 1, 0);
return 0;
exit:
while (i--) {
led_classdev_unregister(&pca955x->leds[i].led_cdev);
cancel_work_sync(&pca955x->leds[i].work);
}
kfree(pca955x->leds);
exit_nomem:
kfree(pca955x);
return err;
}
static int __devexit pca955x_remove(struct i2c_client *client)
{
struct pca955x *pca955x = i2c_get_clientdata(client);
int i;
for (i = 0; i < pca955x->chipdef->bits; i++) {
led_classdev_unregister(&pca955x->leds[i].led_cdev);
cancel_work_sync(&pca955x->leds[i].work);
}
kfree(pca955x->leds);
kfree(pca955x);
return 0;
}
static struct i2c_driver pca955x_driver = {
.driver = {
.name = "leds-pca955x",
.owner = THIS_MODULE,
},
.probe = pca955x_probe,
.remove = __devexit_p(pca955x_remove),
.id_table = pca955x_id,
};
module_i2c_driver(pca955x_driver);
MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>");
MODULE_DESCRIPTION("PCA955x LED driver");
MODULE_LICENSE("GPL v2");