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alistair23-linux/drivers/leds/leds-pca963x.c
Javier Martinez Canillas 4d59ed8545 leds: Export OF module alias information in missing drivers 
The I2C core always reports the MODALIAS uevent as "i2c:<modalias>"
regardless of the mechanism that was used to register the device
(i.e: OF or board code) and the table that is used later to match
the driver with the device (i.e: I2C id table or OF match table).

So drivers needs to export the I2C id table and this be built into
the module or udev won't have the necessary information to autoload
the needed driver module when the device is added.

But this means that OF-only drivers needs to have both OF and I2C id
tables that have to be kept in sync and also the dev node compatible
manufacturer prefix is stripped when reporting the MODALIAS. Which can
lead to issues if two vendors use the same I2C device name for example.

To avoid the above, the I2C core behavior may be changed in the future
to not require an SPI device table for OF-only drivers and report the
OF module alias. So, it's better to also export the OF table even when
is unused now to prevent breaking module loading when the core changes.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
2015-08-28 14:06:30 +02:00

474 lines
12 KiB
C
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/*
* 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", &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");
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