/*
* Copyright 2011 bct electronic GmbH
*
* Author: Peter Meerwald <p.meerwald@bct-electronic.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)
*
* 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 'PCA9633_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-pca9633.h>
/* LED select registers determine the source that drives LED outputs */
#define PCA9633_LED_OFF 0x0 /* LED driver off */
#define PCA9633_LED_ON 0x1 /* LED driver on */
#define PCA9633_LED_PWM 0x2 /* Controlled through PWM */
#define PCA9633_LED_GRP_PWM 0x3 /* Controlled through PWM/GRPPWM */
#define PCA9633_MODE2_DMBLNK 0x20 /* Enable blinking */
#define PCA9633_MODE1 0x00
#define PCA9633_MODE2 0x01
#define PCA9633_PWM_BASE 0x02
#define PCA9633_GRPPWM 0x06
#define PCA9633_GRPFREQ 0x07
#define PCA9633_LEDOUT 0x08
/* Total blink period in milliseconds */
#define PCA9632_BLINK_PERIOD_MIN 42
#define PCA9632_BLINK_PERIOD_MAX 10667
static const struct i2c_device_id pca9633_id[] = {
{ "pca9633", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, pca9633_id);
enum pca9633_cmd {
BRIGHTNESS_SET,
BLINK_SET,
};
struct pca9633_led {
struct i2c_client *client;
struct work_struct work;
enum led_brightness brightness;
struct led_classdev led_cdev;
int led_num; /* 0 .. 3 potentially */
enum pca9633_cmd cmd;
char name[32];
u8 gdc;
u8 gfrq;
};
static void pca9633_brightness_work(struct pca9633_led *pca9633)
{
u8 ledout = i2c_smbus_read_byte_data(pca9633->client, PCA9633_LEDOUT);
int shift = 2 * pca9633->led_num;
u8 mask = 0x3 << shift;
switch (pca9633->brightness) {
case LED_FULL:
i2c_smbus_write_byte_data(pca9633->client, PCA9633_LEDOUT,
(ledout & ~mask) | (PCA9633_LED_ON << shift));
break;
case LED_OFF:
i2c_smbus_write_byte_data(pca9633->client, PCA9633_LEDOUT,
ledout & ~mask);
break;
default:
i2c_smbus_write_byte_data(pca9633->client,
PCA9633_PWM_BASE + pca9633->led_num,
pca9633->brightness);
i2c_smbus_write_byte_data(pca9633->client, PCA9633_LEDOUT,
(ledout & ~mask) | (PCA9633_LED_PWM << shift));
break;
}
}
static void pca9633_blink_work(struct pca9633_led *pca9633)
{
u8 ledout = i2c_smbus_read_byte_data(pca9633->client, PCA9633_LEDOUT);
u8 mode2 = i2c_smbus_read_byte_data(pca9633->client, PCA9633_MODE2);
int shift = 2 * pca9633->led_num;
u8 mask = 0x3 << shift;
i2c_smbus_write_byte_data(pca9633->client, PCA9633_GRPPWM,
pca9633->gdc);
i2c_smbus_write_byte_data(pca9633->client, PCA9633_GRPFREQ,
pca9633->gfrq);
if (!(mode2 & PCA9633_MODE2_DMBLNK))
i2c_smbus_write_byte_data(pca9633->client, PCA9633_MODE2,
mode2 | PCA9633_MODE2_DMBLNK);
if ((ledout & mask) != (PCA9633_LED_GRP_PWM << shift))
i2c_smbus_write_byte_data(pca9633->client, PCA9633_LEDOUT,
(ledout & ~mask) | (PCA9633_LED_GRP_PWM << shift));
}
static void pca9633_work(struct work_struct *work)
{
struct pca9633_led *pca9633 = container_of(work,
struct pca9633_led, work);
switch (pca9633->cmd) {
case BRIGHTNESS_SET:
pca9633_brightness_work(pca9633);
break;
case BLINK_SET:
pca9633_blink_work(pca9633);
break;
}
}
static void pca9633_led_set(struct led_classdev *led_cdev,
enum led_brightness value)
{
struct pca9633_led *pca9633;
pca9633 = container_of(led_cdev, struct pca9633_led, led_cdev);
pca9633->cmd = BRIGHTNESS_SET;
pca9633->brightness = value;
/*
* Must use workqueue for the actual I/O since I2C operations
* can sleep.
*/
schedule_work(&pca9633->work);
}
static int pca9633_blink_set(struct led_classdev *led_cdev,
unsigned long *delay_on, unsigned long *delay_off)
{
struct pca9633_led *pca9633;
unsigned long time_on, time_off, period;
u8 gdc, gfrq;
pca9633 = container_of(led_cdev, struct pca9633_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 < PCA9632_BLINK_PERIOD_MIN) ||
(period > PCA9632_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;
pca9633->cmd = BLINK_SET;
pca9633->gdc = gdc;
pca9633->gfrq = gfrq;
/*
* Must use workqueue for the actual I/O since I2C operations
* can sleep.
*/
schedule_work(&pca9633->work);
*delay_on = time_on;
*delay_off = time_off;
return 0;
}
#if IS_ENABLED(CONFIG_OF)
static struct pca9633_platform_data *
pca9633_dt_init(struct i2c_client *client)
{
struct device_node *np = client->dev.of_node, *child;
struct pca9633_platform_data *pdata;
struct led_info *pca9633_leds;
int count;
count = of_get_child_count(np);
if (!count || count > 4)
return ERR_PTR(-ENODEV);
pca9633_leds = devm_kzalloc(&client->dev,
sizeof(struct led_info) * count, GFP_KERNEL);
if (!pca9633_leds)
return ERR_PTR(-ENOMEM);
for_each_child_of_node(np, child) {
struct led_info led;
u32 reg;
int res;
led.name =
of_get_property(child, "label", NULL) ? : child->name;
led.default_trigger =
of_get_property(child, "linux,default-trigger", NULL);
res = of_property_read_u32(child, "reg", ®);
if (res != 0)
continue;
pca9633_leds[reg] = led;
}
pdata = devm_kzalloc(&client->dev,
sizeof(struct pca9633_platform_data), GFP_KERNEL);
if (!pdata)
return ERR_PTR(-ENOMEM);
pdata->leds.leds = pca9633_leds;
pdata->leds.num_leds = count;
/* default to open-drain unless totem pole (push-pull) is specified */
if (of_property_read_bool(np, "nxp,totem-pole"))
pdata->outdrv = PCA9633_TOTEM_POLE;
else
pdata->outdrv = PCA9633_OPEN_DRAIN;
/* default to software blinking unless hardware blinking is specified */
if (of_property_read_bool(np, "nxp,hw-blink"))
pdata->blink_type = PCA9633_HW_BLINK;
else
pdata->blink_type = PCA9633_SW_BLINK;
return pdata;
}
static const struct of_device_id of_pca9633_match[] = {
{ .compatible = "nxp,pca963x", },
{},
};
#else
static struct pca9633_platform_data *
pca9633_dt_init(struct i2c_client *client)
{
return ERR_PTR(-ENODEV);
}
#endif
static int pca9633_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct pca9633_led *pca9633;
struct pca9633_platform_data *pdata;
int i, err;
pdata = client->dev.platform_data;
if (!pdata) {
pdata = pca9633_dt_init(client);
if (IS_ERR(pdata)) {
dev_warn(&client->dev, "could not parse configuration\n");
pdata = NULL;
}
}
if (pdata) {
if (pdata->leds.num_leds <= 0 || pdata->leds.num_leds > 4) {
dev_err(&client->dev, "board info must claim at most 4 LEDs");
return -EINVAL;
}
}
pca9633 = devm_kzalloc(&client->dev, 4 * sizeof(*pca9633), GFP_KERNEL);
if (!pca9633)
return -ENOMEM;
i2c_set_clientdata(client, pca9633);
for (i = 0; i < 4; i++) {
pca9633[i].client = client;
pca9633[i].led_num = i;
/* Platform data can specify LED names and default triggers */
if (pdata && i < pdata->leds.num_leds) {
if (pdata->leds.leds[i].name)
snprintf(pca9633[i].name,
sizeof(pca9633[i].name), "pca9633:%s",
pdata->leds.leds[i].name);
if (pdata->leds.leds[i].default_trigger)
pca9633[i].led_cdev.default_trigger =
pdata->leds.leds[i].default_trigger;
} else {
snprintf(pca9633[i].name, sizeof(pca9633[i].name),
"pca9633:%d", i);
}
pca9633[i].led_cdev.name = pca9633[i].name;
pca9633[i].led_cdev.brightness_set = pca9633_led_set;
if (pdata && pdata->blink_type == PCA9633_HW_BLINK)
pca9633[i].led_cdev.blink_set = pca9633_blink_set;
INIT_WORK(&pca9633[i].work, pca9633_work);
err = led_classdev_register(&client->dev, &pca9633[i].led_cdev);
if (err < 0)
goto exit;
}
/* Disable LED all-call address and set normal mode */
i2c_smbus_write_byte_data(client, PCA9633_MODE1, 0x00);
/* Configure output: open-drain or totem pole (push-pull) */
if (pdata && pdata->outdrv == PCA9633_OPEN_DRAIN)
i2c_smbus_write_byte_data(client, PCA9633_MODE2, 0x01);
/* Turn off LEDs */
i2c_smbus_write_byte_data(client, PCA9633_LEDOUT, 0x00);
return 0;
exit:
while (i--) {
led_classdev_unregister(&pca9633[i].led_cdev);
cancel_work_sync(&pca9633[i].work);
}
return err;
}
static int pca9633_remove(struct i2c_client *client)
{
struct pca9633_led *pca9633 = i2c_get_clientdata(client);
int i;
for (i = 0; i < 4; i++) {
led_classdev_unregister(&pca9633[i].led_cdev);
cancel_work_sync(&pca9633[i].work);
}
return 0;
}
static struct i2c_driver pca9633_driver = {
.driver = {
.name = "leds-pca9633",
.owner = THIS_MODULE,
.of_match_table = of_match_ptr(of_pca9633_match),
},
.probe = pca9633_probe,
.remove = pca9633_remove,
.id_table = pca9633_id,
};
module_i2c_driver(pca9633_driver);
MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
MODULE_DESCRIPTION("PCA9633 LED driver");
MODULE_LICENSE("GPL v2");
