- 根目录:
- drivers
- leds
- leds-pca963x.c
/*
* Copyright 2011 bct electronic GmbH
* Copyright 2013 Qtechnology/AS
*
* Author: Peter Meerwald <p.meerwald@bct-electronic.com>
* Author: Ricardo Ribalda <ricardo.ribalda@gmail.com>
*
* Based on leds-pca955x.c
*
* 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 the PCA9633 I2C LED driver (7-bit slave address 0x62)
* LED driver for the PCA9634/5 I2C LED driver (7-bit slave address set by hw.)
*
* Note that hardware blinking violates the leds infrastructure driver
* interface since the hardware only supports blinking all LEDs with the
* same delay_on/delay_off rates. That is, only the LEDs that are set to
* blink will actually blink but all LEDs that are set to blink will blink
* in identical fashion. The delay_on/delay_off values of the last LED
* that is set to blink will be used for all of the blinking LEDs.
* Hardware blinking is disabled by default but can be enabled by setting
* the 'blink_type' member in the platform_data struct to 'PCA963X_HW_BLINK'
* or by adding the 'nxp,hw-blink' property to the DTS.
*/
#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 <linux/slab.h>
#include <linux/of.h>
#include <linux/platform_data/leds-pca963x.h>
/* LED select registers determine the source that drives LED outputs */
#define PCA963X_LED_OFF 0x0 /* LED driver off */
#define PCA963X_LED_ON 0x1 /* LED driver on */
#define PCA963X_LED_PWM 0x2 /* Controlled through PWM */
#define PCA963X_LED_GRP_PWM 0x3 /* Controlled through PWM/GRPPWM */
#define PCA963X_MODE2_DMBLNK 0x20 /* Enable blinking */
#define PCA963X_MODE1 0x00
#define PCA963X_MODE2 0x01
#define PCA963X_PWM_BASE 0x02
enum pca963x_type {
pca9633,
pca9634,
pca9635,
};
struct pca963x_chipdef {
u8 grppwm;
u8 grpfreq;
u8 ledout_base;
int n_leds;
};
static struct pca963x_chipdef pca963x_chipdefs[] = {
[pca9633] = {
.grppwm = 0x6,
.grpfreq = 0x7,
.ledout_base = 0x8,
.n_leds = 4,
},
[pca9634] = {
.grppwm = 0xa,
.grpfreq = 0xb,
.ledout_base = 0xc,
.n_leds = 8,
},
[pca9635] = {
.grppwm = 0x12,
.grpfreq = 0x13,
.ledout_base = 0x14,
.n_leds = 16,
},
};
/* Total blink period in milliseconds */
#define PCA963X_BLINK_PERIOD_MIN 42
#define PCA963X_BLINK_PERIOD_MAX 10667
static const struct i2c_device_id pca963x_id[] = {
{ "pca9632", pca9633 },
{ "pca9633", pca9633 },
{ "pca9634", pca9634 },
{ "pca9635", pca9635 },
{ }
};
MODULE_DEVICE_TABLE(i2c, pca963x_id);
enum pca963x_cmd {
BRIGHTNESS_SET,
BLINK_SET,
};
struct pca963x_led;
struct pca963x {
struct pca963x_chipdef *chipdef;
struct mutex mutex;
struct i2c_client *client;
struct pca963x_led *leds;
};
struct pca963x_led {
struct pca963x *chip;
struct work_struct work;
enum led_brightness brightness;
struct led_classdev led_cdev;
int led_num; /* 0 .. 15 potentially */
enum pca963x_cmd cmd;
char name[32];
u8 gdc;
u8 gfrq;
};
static void pca963x_brightness_work(struct pca963x_led *pca963x)
{
u8 ledout_addr = pca963x->chip->chipdef->ledout_base
+ (pca963x->led_num / 4);
u8 ledout;
int shift = 2 * (pca963x->led_num % 4);
u8 mask = 0x3 << shift;
mutex_lock(&pca963x->chip->mutex);
ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
switch (pca963x->brightness) {
case LED_FULL:
i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
(ledout & ~mask) | (PCA963X_LED_ON << shift));
break;
case LED_OFF:
i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
ledout & ~mask);
break;
default:
i2c_smbus_write_byte_data(pca963x->chip->client,
PCA963X_PWM_BASE + pca963x->led_num,
pca963x->brightness);
i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
(ledout & ~mask) | (PCA963X_LED_PWM << shift));
break;
}
mutex_unlock(&pca963x->chip->mutex);
}
static void pca963x_blink_work(struct pca963x_led *pca963x)
{
u8 ledout_addr = pca963x->chip->chipdef->ledout_base +
(pca963x->led_num / 4);
u8 ledout;
u8 mode2 = i2c_smbus_read_byte_data(pca963x->chip->client,
PCA963X_MODE2);
int shift = 2 * (pca963x->led_num % 4);
u8 mask = 0x3 << shift;
i2c_smbus_write_byte_data(pca963x->chip->client,
pca963x->chip->chipdef->grppwm, pca963x->gdc);
i2c_smbus_write_byte_data(pca963x->chip->client,
pca963x->chip->chipdef->grpfreq, pca963x->gfrq);
if (!(mode2 & PCA963X_MODE2_DMBLNK))
i2c_smbus_write_byte_data(pca963x->chip->client, PCA963X_MODE2,
mode2 | PCA963X_MODE2_DMBLNK);
mutex_lock(&pca963x->chip->mutex);
ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
if ((ledout & mask) != (PCA963X_LED_GRP_PWM << shift))
i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
(ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift));
mutex_unlock(&pca963x->chip->mutex);
}
static void pca963x_work(struct work_struct *work)
{
struct pca963x_led *pca963x = container_of(work,
struct pca963x_led, work);
switch (pca963x->cmd) {
case BRIGHTNESS_SET:
pca963x_brightness_work(pca963x);
break;
case BLINK_SET:
pca963x_blink_work(pca963x);
break;
}
}
static void pca963x_led_set(struct led_classdev *led_cdev,
enum led_brightness value)
{
struct pca963x_led *pca963x;
pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);
pca963x->cmd = BRIGHTNESS_SET;
pca963x->brightness = value;
/*
* Must use workqueue for the actual I/O since I2C operations
* can sleep.
*/
schedule_work(&pca963x->work);
}
static int pca963x_blink_set(struct led_classdev *led_cdev,
unsigned long *delay_on, unsigned long *delay_off)
{
struct pca963x_led *pca963x;
unsigned long time_on, time_off, period;
u8 gdc, gfrq;
pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);
time_on = *delay_on;
time_off = *delay_off;
/* If both zero, pick reasonable defaults of 500ms each */
if (!time_on && !time_off) {
time_on = 500;
time_off = 500;
}
period = time_on + time_off;
/* If period not supported by hardware, default to someting sane. */
if ((period < PCA963X_BLINK_PERIOD_MIN) ||
(period > PCA963X_BLINK_PERIOD_MAX)) {
time_on = 500;
time_off = 500;
period = time_on + time_off;
}
/*
* From manual: duty cycle = (GDC / 256) ->
* (time_on / period) = (GDC / 256) ->
* GDC = ((time_on * 256) / period)
*/
gdc = (time_on * 256) / period;
/*
* From manual: period = ((GFRQ + 1) / 24) in seconds.
* So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
* GFRQ = ((period * 24 / 1000) - 1)
*/
gfrq = (period * 24 / 1000) - 1;
pca963x->cmd = BLINK_SET;
pca963x->gdc = gdc;
pca963x->gfrq = gfrq;
/*
* Must use workqueue for the actual I/O since I2C operations
* can sleep.
*/
schedule_work(&pca963x->work);
*delay_on = time_on;
*delay_off = time_off;
return 0;
}
#if IS_ENABLED(CONFIG_OF)
static struct pca963x_platform_data *
pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
{
struct device_node *np = client->dev.of_node, *child;
struct pca963x_platform_data *pdata;
struct led_info *pca963x_leds;
int count;
count = of_get_child_count(np);
if (!count || count > chip->n_leds)
return ERR_PTR(-ENODEV);
pca963x_leds = devm_kzalloc(&client->dev,
sizeof(struct led_info) * chip->n_leds, GFP_KERNEL);
if (!pca963x_leds)
return ERR_PTR(-ENOMEM);
for_each_child_of_node(np, child) {
struct led_info led = {};
u32 reg;
int res;
res = of_property_read_u32(child, "reg", ®);
if ((res != 0) || (reg >= chip->n_leds))
continue;
led.name =
of_get_property(child, "label", NULL) ? : child->name;
led.default_trigger =
of_get_property(child, "linux,default-trigger", NULL);
pca963x_leds[reg] = led;
}
pdata = devm_kzalloc(&client->dev,
sizeof(struct pca963x_platform_data), GFP_KERNEL);
if (!pdata)
return ERR_PTR(-ENOMEM);
pdata->leds.leds = pca963x_leds;
pdata->leds.num_leds = chip->n_leds;
/* default to open-drain unless totem pole (push-pull) is specified */
if (of_property_read_bool(np, "nxp,totem-pole"))
pdata->outdrv = PCA963X_TOTEM_POLE;
else
pdata->outdrv = PCA963X_OPEN_DRAIN;
/* default to software blinking unless hardware blinking is specified */
if (of_property_read_bool(np, "nxp,hw-blink"))
pdata->blink_type = PCA963X_HW_BLINK;
else
pdata->blink_type = PCA963X_SW_BLINK;
return pdata;
}
static const struct of_device_id of_pca963x_match[] = {
{ .compatible = "nxp,pca9632", },
{ .compatible = "nxp,pca9633", },
{ .compatible = "nxp,pca9634", },
{ .compatible = "nxp,pca9635", },
{},
};
MODULE_DEVICE_TABLE(of, of_pca963x_match);
#else
static struct pca963x_platform_data *
pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
{
return ERR_PTR(-ENODEV);
}
#endif
static int pca963x_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct pca963x *pca963x_chip;
struct pca963x_led *pca963x;
struct pca963x_platform_data *pdata;
struct pca963x_chipdef *chip;
int i, err;
chip = &pca963x_chipdefs[id->driver_data];
pdata = dev_get_platdata(&client->dev);
if (!pdata) {
pdata = pca963x_dt_init(client, chip);
if (IS_ERR(pdata)) {
dev_warn(&client->dev, "could not parse configuration\n");
pdata = NULL;
}
}
if (pdata && (pdata->leds.num_leds < 1 ||
pdata->leds.num_leds > chip->n_leds)) {
dev_err(&client->dev, "board info must claim 1-%d LEDs",
chip->n_leds);
return -EINVAL;
}
pca963x_chip = devm_kzalloc(&client->dev, sizeof(*pca963x_chip),
GFP_KERNEL);
if (!pca963x_chip)
return -ENOMEM;
pca963x = devm_kzalloc(&client->dev, chip->n_leds * sizeof(*pca963x),
GFP_KERNEL);
if (!pca963x)
return -ENOMEM;
i2c_set_clientdata(client, pca963x_chip);
mutex_init(&pca963x_chip->mutex);
pca963x_chip->chipdef = chip;
pca963x_chip->client = client;
pca963x_chip->leds = pca963x;
/* Turn off LEDs by default*/
for (i = 0; i < chip->n_leds / 4; i++)
i2c_smbus_write_byte_data(client, chip->ledout_base + i, 0x00);
for (i = 0; i < chip->n_leds; i++) {
pca963x[i].led_num = i;
pca963x[i].chip = pca963x_chip;
/* Platform data can specify LED names and default triggers */
if (pdata && i < pdata->leds.num_leds) {
if (pdata->leds.leds[i].name)
snprintf(pca963x[i].name,
sizeof(pca963x[i].name), "pca963x:%s",
pdata->leds.leds[i].name);
if (pdata->leds.leds[i].default_trigger)
pca963x[i].led_cdev.default_trigger =
pdata->leds.leds[i].default_trigger;
}
if (!pdata || i >= pdata->leds.num_leds ||
!pdata->leds.leds[i].name)
snprintf(pca963x[i].name, sizeof(pca963x[i].name),
"pca963x:%d:%.2x:%d", client->adapter->nr,
client->addr, i);
pca963x[i].led_cdev.name = pca963x[i].name;
pca963x[i].led_cdev.brightness_set = pca963x_led_set;
if (pdata && pdata->blink_type == PCA963X_HW_BLINK)
pca963x[i].led_cdev.blink_set = pca963x_blink_set;
INIT_WORK(&pca963x[i].work, pca963x_work);
err = led_classdev_register(&client->dev, &pca963x[i].led_cdev);
if (err < 0)
goto exit;
}
/* Disable LED all-call address and set normal mode */
i2c_smbus_write_byte_data(client, PCA963X_MODE1, 0x00);
if (pdata) {
/* Configure output: open-drain or totem pole (push-pull) */
if (pdata->outdrv == PCA963X_OPEN_DRAIN)
i2c_smbus_write_byte_data(client, PCA963X_MODE2, 0x01);
else
i2c_smbus_write_byte_data(client, PCA963X_MODE2, 0x05);
}
return 0;
exit:
while (i--) {
led_classdev_unregister(&pca963x[i].led_cdev);
cancel_work_sync(&pca963x[i].work);
}
return err;
}
static int pca963x_remove(struct i2c_client *client)
{
struct pca963x *pca963x = i2c_get_clientdata(client);
int i;
for (i = 0; i < pca963x->chipdef->n_leds; i++) {
led_classdev_unregister(&pca963x->leds[i].led_cdev);
cancel_work_sync(&pca963x->leds[i].work);
}
return 0;
}
static struct i2c_driver pca963x_driver = {
.driver = {
.name = "leds-pca963x",
.of_match_table = of_match_ptr(of_pca963x_match),
},
.probe = pca963x_probe,
.remove = pca963x_remove,
.id_table = pca963x_id,
};
module_i2c_driver(pca963x_driver);
MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
MODULE_DESCRIPTION("PCA963X LED driver");
MODULE_LICENSE("GPL v2");