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leds: add LED driver for CR0014114 board

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This patch adds a LED class driver for the RGB LEDs found on
the Crane Merchandising System CR0014114 LEDs board.

Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
This commit is contained in:
Oleh Kravchenko 2018-04-02 15:53:50 +03:00 committed by Jacek Anaszewski
parent b9dd691553
commit 9e50d5fb0d
3 changed files with 329 additions and 0 deletions
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13
drivers/leds/Kconfig
View File

@ -104,6 +104,19 @@ config LEDS_CPCAP
This option enables support for LEDs offered by Motorola's
CPCAP PMIC.
config LEDS_CR0014114
tristate "LED Support for Crane CR0014114"
depends on LEDS_CLASS
depends on SPI
depends on OF
help
This option enables support for CR0014114 LED Board which
is widely used in vending machines produced by
Crane Merchandising Systems.
To compile this driver as a module, choose M here: the module
will be called leds-cr0014114.
config LEDS_LM3530
tristate "LCD Backlight driver for LM3530"
depends on LEDS_CLASS

1
drivers/leds/Makefile
View File

@ -78,6 +78,7 @@ obj-$(CONFIG_LEDS_MT6323) += leds-mt6323.o
obj-$(CONFIG_LEDS_LM3692X) += leds-lm3692x.o
# LED SPI Drivers
obj-$(CONFIG_LEDS_CR0014114) += leds-cr0014114.o
obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o
# LED Userspace Drivers

315
drivers/leds/leds-cr0014114.c Normal file
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@ -0,0 +1,315 @@
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2018 Crane Merchandising Systems. All rights reserved.
// Copyright (C) 2018 Oleh Kravchenko <oleg@kaa.org.ua>
#include <linux/delay.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/spi/spi.h>
#include <linux/workqueue.h>
#include <uapi/linux/uleds.h>
/*
* CR0014114 SPI protocol descrtiption:
* +----+-----------------------------------+----+
* | CMD| BRIGHTNESS |CRC |
* +----+-----------------------------------+----+
* | | LED0| LED1| LED2| LED3| LED4| LED5| |
* | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
* | |R|G|B|R|G|B|R|G|B|R|G|B|R|G|B|R|G|B| |
* | 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1 |
* | |1|1|1|1|1|1|1|1|1|1|1|1|1|1|1|1|1|1| |
* | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
* | | 18 | |
* +----+-----------------------------------+----+
* | 20 |
* +---------------------------------------------+
*
* PS: Boards can be connected to the chain:
* SPI -> board0 -> board1 -> board2 ..
*/
/* CR0014114 SPI commands */
#define CR_SET_BRIGHTNESS 0x80
#define CR_INIT_REENUMERATE 0x81
#define CR_NEXT_REENUMERATE 0x82
/* CR0014114 default settings */
#define CR_MAX_BRIGHTNESS GENMASK(6, 0)
#define CR_FW_DELAY_MSEC 10
#define CR_RECOUNT_DELAY (HZ * 3600)
struct cr0014114_led {
char name[LED_MAX_NAME_SIZE];
struct cr0014114 *priv;
struct led_classdev ldev;
u8 brightness;
};
struct cr0014114 {
bool do_recount;
size_t count;
struct delayed_work work;
struct device *dev;
struct mutex lock;
struct spi_device *spi;
u8 *buf;
unsigned long delay;
struct cr0014114_led leds[];
};
static void cr0014114_calc_crc(u8 *buf, const size_t len)
{
size_t i;
u8 crc;
for (i = 1, crc = 1; i < len - 1; i++)
crc += buf[i];
crc |= BIT(7);
/* special case when CRC matches the SPI commands */
if (crc == CR_SET_BRIGHTNESS ||
crc == CR_INIT_REENUMERATE ||
crc == CR_NEXT_REENUMERATE)
crc = 0xfe;
buf[len - 1] = crc;
}
static int cr0014114_recount(struct cr0014114 *priv)
{
int ret;
size_t i;
u8 cmd;
dev_dbg(priv->dev, "LEDs recount is started\n");
cmd = CR_INIT_REENUMERATE;
ret = spi_write(priv->spi, &cmd, sizeof(cmd));
if (ret)
goto err;
cmd = CR_NEXT_REENUMERATE;
for (i = 0; i < priv->count; i++) {
msleep(CR_FW_DELAY_MSEC);
ret = spi_write(priv->spi, &cmd, sizeof(cmd));
if (ret)
goto err;
}
err:
dev_dbg(priv->dev, "LEDs recount is finished\n");
if (ret)
dev_err(priv->dev, "with error %d", ret);
return ret;
}
static int cr0014114_sync(struct cr0014114 *priv)
{
int ret;
size_t i;
unsigned long udelay, now = jiffies;
/* to avoid SPI mistiming with firmware we should wait some time */
if (time_after(priv->delay, now)) {
udelay = jiffies_to_usecs(priv->delay - now);
usleep_range(udelay, udelay + 1);
}
if (unlikely(priv->do_recount)) {
ret = cr0014114_recount(priv);
if (ret)
goto err;
priv->do_recount = false;
msleep(CR_FW_DELAY_MSEC);
}
priv->buf[0] = CR_SET_BRIGHTNESS;
for (i = 0; i < priv->count; i++)
priv->buf[i + 1] = priv->leds[i].brightness;
cr0014114_calc_crc(priv->buf, priv->count + 2);
ret = spi_write(priv->spi, priv->buf, priv->count + 2);
err:
priv->delay = jiffies + msecs_to_jiffies(CR_FW_DELAY_MSEC);
return ret;
}
static void cr0014114_recount_work(struct work_struct *work)
{
int ret;
struct cr0014114 *priv = container_of(work,
struct cr0014114,
work.work);
mutex_lock(&priv->lock);
priv->do_recount = true;
ret = cr0014114_sync(priv);
mutex_unlock(&priv->lock);
if (ret)
dev_warn(priv->dev, "sync of LEDs failed %d\n", ret);
schedule_delayed_work(&priv->work, CR_RECOUNT_DELAY);
}
static int cr0014114_set_sync(struct led_classdev *ldev,
enum led_brightness brightness)
{
int ret;
struct cr0014114_led *led = container_of(ldev,
struct cr0014114_led,
ldev);
dev_dbg(led->priv->dev, "Set brightness of %s to %d\n",
led->name, brightness);
mutex_lock(&led->priv->lock);
led->brightness = (u8)brightness;
ret = cr0014114_sync(led->priv);
mutex_unlock(&led->priv->lock);
return ret;
}
static int cr0014114_probe_dt(struct cr0014114 *priv)
{
size_t i = 0;
struct cr0014114_led *led;
struct fwnode_handle *child;
struct device_node *np;
int ret;
const char *str;
device_for_each_child_node(priv->dev, child) {
np = to_of_node(child);
led = &priv->leds[i];
ret = fwnode_property_read_string(child, "label", &str);
if (ret)
snprintf(led->name, sizeof(led->name),
"cr0014114::");
else
snprintf(led->name, sizeof(led->name),
"cr0014114:%s", str);
fwnode_property_read_string(child, "linux,default-trigger",
&led->ldev.default_trigger);
led->priv = priv;
led->ldev.name = led->name;
led->ldev.max_brightness = CR_MAX_BRIGHTNESS;
led->ldev.brightness_set_blocking = cr0014114_set_sync;
ret = devm_of_led_classdev_register(priv->dev, np,
&led->ldev);
if (ret) {
dev_err(priv->dev,
"failed to register LED device %s, err %d",
led->name, ret);
fwnode_handle_put(child);
return ret;
}
led->ldev.dev->of_node = np;
i++;
}
return 0;
}
static int cr0014114_probe(struct spi_device *spi)
{
struct cr0014114 *priv;
size_t count;
int ret;
count = device_get_child_node_count(&spi->dev);
if (!count) {
dev_err(&spi->dev, "LEDs are not defined in device tree!");
return -ENODEV;
}
priv = devm_kzalloc(&spi->dev,
sizeof(*priv) + sizeof(*priv->leds) * count,
GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->buf = devm_kzalloc(&spi->dev, count + 2, GFP_KERNEL);
if (!priv->buf)
return -ENOMEM;
mutex_init(&priv->lock);
INIT_DELAYED_WORK(&priv->work, cr0014114_recount_work);
priv->count = count;
priv->dev = &spi->dev;
priv->spi = spi;
priv->delay = jiffies -
msecs_to_jiffies(CR_FW_DELAY_MSEC);
priv->do_recount = true;
ret = cr0014114_sync(priv);
if (ret) {
dev_err(priv->dev, "first recount failed %d\n", ret);
return ret;
}
priv->do_recount = true;
ret = cr0014114_sync(priv);
if (ret) {
dev_err(priv->dev, "second recount failed %d\n", ret);
return ret;
}
ret = cr0014114_probe_dt(priv);
if (ret)
return ret;
/* setup recount work to workaround buggy firmware */
schedule_delayed_work(&priv->work, CR_RECOUNT_DELAY);
spi_set_drvdata(spi, priv);
return 0;
}
static int cr0014114_remove(struct spi_device *spi)
{
struct cr0014114 *priv = spi_get_drvdata(spi);
cancel_delayed_work_sync(&priv->work);
mutex_destroy(&priv->lock);
return 0;
}
static const struct of_device_id cr0014114_dt_ids[] = {
{ .compatible = "crane,cr0014114", },
{},
};
MODULE_DEVICE_TABLE(of, cr0014114_dt_ids);
static struct spi_driver cr0014114_driver = {
.probe = cr0014114_probe,
.remove = cr0014114_remove,
.driver = {
.name = KBUILD_MODNAME,
.of_match_table = cr0014114_dt_ids,
},
};
module_spi_driver(cr0014114_driver);
MODULE_AUTHOR("Oleh Kravchenko <oleg@kaa.org.ua>");
MODULE_DESCRIPTION("cr0014114 LED driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("spi:cr0014114");