From 9e50d5fb0d1874e7e8750e58b8ee7a27ed63f748 Mon Sep 17 00:00:00 2001 From: Oleh Kravchenko Date: Mon, 2 Apr 2018 15:53:50 +0300 Subject: [PATCH] leds: add LED driver for CR0014114 board 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 Acked-by: Pavel Machek Signed-off-by: Jacek Anaszewski --- drivers/leds/Kconfig | 13 ++ drivers/leds/Makefile | 1 + drivers/leds/leds-cr0014114.c | 315 ++++++++++++++++++++++++++++++++++ 3 files changed, 329 insertions(+) create mode 100644 drivers/leds/leds-cr0014114.c diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig index 2c896c0e69e1..5831814d01d0 100644 --- a/drivers/leds/Kconfig +++ b/drivers/leds/Kconfig @@ -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 diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile index 91eca81cae82..0176e7335994 100644 --- a/drivers/leds/Makefile +++ b/drivers/leds/Makefile @@ -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 diff --git a/drivers/leds/leds-cr0014114.c b/drivers/leds/leds-cr0014114.c new file mode 100644 index 000000000000..a4b1c1dcce7f --- /dev/null +++ b/drivers/leds/leds-cr0014114.c @@ -0,0 +1,315 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2018 Crane Merchandising Systems. All rights reserved. +// Copyright (C) 2018 Oleh Kravchenko + +#include +#include +#include +#include +#include +#include +#include + +/* + * 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 "); +MODULE_DESCRIPTION("cr0014114 LED driver"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("spi:cr0014114");