// SPDX-License-Identifier: GPL-2.0 // Copyright (c) 2019 Crane Merchandising Systems. All rights reserved. // Copyright (C) 2019 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> /* * EL15203000 SPI protocol description: * +-----+---------+ * | LED | COMMAND | * +-----+---------+ * | 1 | 1 | * +-----+---------+ * (*) LEDs MCU board expects 20 msec delay per byte. * * LEDs: * +----------+--------------+-------------------------------------------+ * | ID | NAME | DESCRIPTION | * +----------+--------------+-------------------------------------------+ * | 'P' 0x50 | Pipe | Consists from 5 LEDs, controlled by board | * +----------+--------------+-------------------------------------------+ * | 'S' 0x53 | Screen frame | Light tube around the screen | * +----------+--------------+-------------------------------------------+ * | 'V' 0x56 | Vending area | Highlights a cup of coffee | * +----------+--------------+-------------------------------------------+ * * COMMAND: * +----------+-----------------+--------------+--------------+ * | VALUES | PIPE | SCREEN FRAME | VENDING AREA | * +----------+-----------------+--------------+--------------+ * | '0' 0x30 | Off | * +----------+-----------------------------------------------+ * | '1' 0x31 | On | * +----------+-----------------+--------------+--------------+ * | '2' 0x32 | Cascade | Breathing | * +----------+-----------------+--------------+ * | '3' 0x33 | Inverse cascade | * +----------+-----------------+ * | '4' 0x34 | Bounce | * +----------+-----------------+ * | '5' 0x35 | Inverse bounce | * +----------+-----------------+ */ /* EL15203000 default settings */ #define EL_FW_DELAY_USEC 20000ul #define EL_PATTERN_DELAY_MSEC 800u #define EL_PATTERN_LEN 10u #define EL_PATTERN_HALF_LEN (EL_PATTERN_LEN / 2) enum el15203000_command { /* for all LEDs */ EL_OFF = '0', EL_ON = '1', /* for Screen LED */ EL_SCREEN_BREATHING = '2', /* for Pipe LED */ EL_PIPE_CASCADE = '2', EL_PIPE_INV_CASCADE = '3', EL_PIPE_BOUNCE = '4', EL_PIPE_INV_BOUNCE = '5', }; struct el15203000_led { struct el15203000 *priv; struct led_classdev ldev; u32 reg; }; struct el15203000 { struct device *dev; struct mutex lock; struct spi_device *spi; unsigned long delay; size_t count; struct el15203000_led leds[]; }; static int el15203000_cmd(struct el15203000_led *led, u8 brightness) { int ret; u8 cmd[2]; size_t i; mutex_lock(&led->priv->lock); dev_dbg(led->priv->dev, "Set brightness of 0x%02x(%c) to 0x%02x(%c)", led->reg, led->reg, brightness, brightness); /* to avoid SPI mistiming with firmware we should wait some time */ if (time_after(led->priv->delay, jiffies)) { dev_dbg(led->priv->dev, "Wait %luus to sync", EL_FW_DELAY_USEC); usleep_range(EL_FW_DELAY_USEC, EL_FW_DELAY_USEC + 1); } cmd[0] = led->reg; cmd[1] = brightness; for (i = 0; i < ARRAY_SIZE(cmd); i++) { if (i) usleep_range(EL_FW_DELAY_USEC, EL_FW_DELAY_USEC + 1); ret = spi_write(led->priv->spi, &cmd[i], sizeof(cmd[i])); if (ret) { dev_err(led->priv->dev, "spi_write() error %d", ret); break; } } led->priv->delay = jiffies + usecs_to_jiffies(EL_FW_DELAY_USEC); mutex_unlock(&led->priv->lock); return ret; } static int el15203000_set_blocking(struct led_classdev *ldev, enum led_brightness brightness) { struct el15203000_led *led = container_of(ldev, struct el15203000_led, ldev); return el15203000_cmd(led, brightness == LED_OFF ? EL_OFF : EL_ON); } static int el15203000_pattern_set_S(struct led_classdev *ldev, struct led_pattern *pattern, u32 len, int repeat) { struct el15203000_led *led = container_of(ldev, struct el15203000_led, ldev); if (repeat > 0 || len != 2 || pattern[0].delta_t != 4000 || pattern[0].brightness != 0 || pattern[1].delta_t != 4000 || pattern[1].brightness != 1) return -EINVAL; dev_dbg(led->priv->dev, "Breathing mode for 0x%02x(%c)", led->reg, led->reg); return el15203000_cmd(led, EL_SCREEN_BREATHING); } static bool is_cascade(const struct led_pattern *pattern, u32 len, bool inv, bool right) { int val, t; u32 i; if (len != EL_PATTERN_HALF_LEN) return false; val = right ? BIT(4) : BIT(0); for (i = 0; i < len; i++) { t = inv ? ~val & GENMASK(4, 0) : val; if (pattern[i].delta_t != EL_PATTERN_DELAY_MSEC || pattern[i].brightness != t) return false; val = right ? val >> 1 : val << 1; } return true; } static bool is_bounce(const struct led_pattern *pattern, u32 len, bool inv) { if (len != EL_PATTERN_LEN) return false; return is_cascade(pattern, EL_PATTERN_HALF_LEN, inv, false) && is_cascade(pattern + EL_PATTERN_HALF_LEN, EL_PATTERN_HALF_LEN, inv, true); } static int el15203000_pattern_set_P(struct led_classdev *ldev, struct led_pattern *pattern, u32 len, int repeat) { u8 cmd; struct el15203000_led *led = container_of(ldev, struct el15203000_led, ldev); if (repeat > 0) return -EINVAL; if (is_cascade(pattern, len, false, false)) { dev_dbg(led->priv->dev, "Cascade mode for 0x%02x(%c)", led->reg, led->reg); cmd = EL_PIPE_CASCADE; } else if (is_cascade(pattern, len, true, false)) { dev_dbg(led->priv->dev, "Inverse cascade mode for 0x%02x(%c)", led->reg, led->reg); cmd = EL_PIPE_INV_CASCADE; } else if (is_bounce(pattern, len, false)) { dev_dbg(led->priv->dev, "Bounce mode for 0x%02x(%c)", led->reg, led->reg); cmd = EL_PIPE_BOUNCE; } else if (is_bounce(pattern, len, true)) { dev_dbg(led->priv->dev, "Inverse bounce mode for 0x%02x(%c)", led->reg, led->reg); cmd = EL_PIPE_INV_BOUNCE; } else { dev_err(led->priv->dev, "Invalid hw_pattern for 0x%02x(%c)!", led->reg, led->reg); return -EINVAL; } return el15203000_cmd(led, cmd); } static int el15203000_pattern_clear(struct led_classdev *ldev) { struct el15203000_led *led = container_of(ldev, struct el15203000_led, ldev); return el15203000_cmd(led, EL_OFF); } static int el15203000_probe_dt(struct el15203000 *priv) { struct el15203000_led *led = priv->leds; struct fwnode_handle *child; int ret; device_for_each_child_node(priv->dev, child) { struct led_init_data init_data = {}; ret = fwnode_property_read_u32(child, "reg", &led->reg); if (ret) { dev_err(priv->dev, "LED without ID number"); fwnode_handle_put(child); break; } if (led->reg > U8_MAX) { dev_err(priv->dev, "LED value %d is invalid", led->reg); fwnode_handle_put(child); return -EINVAL; } fwnode_property_read_string(child, "linux,default-trigger", &led->ldev.default_trigger); led->priv = priv; led->ldev.max_brightness = LED_ON; led->ldev.brightness_set_blocking = el15203000_set_blocking; if (led->reg == 'S') { led->ldev.pattern_set = el15203000_pattern_set_S; led->ldev.pattern_clear = el15203000_pattern_clear; } else if (led->reg == 'P') { led->ldev.pattern_set = el15203000_pattern_set_P; led->ldev.pattern_clear = el15203000_pattern_clear; } init_data.fwnode = child; ret = devm_led_classdev_register_ext(priv->dev, &led->ldev, &init_data); if (ret) { dev_err(priv->dev, "failed to register LED device %s, err %d", led->ldev.name, ret); fwnode_handle_put(child); break; } led++; } return ret; } static int el15203000_probe(struct spi_device *spi) { struct el15203000 *priv; size_t count; 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, struct_size(priv, leds, count), GFP_KERNEL); if (!priv) return -ENOMEM; mutex_init(&priv->lock); priv->count = count; priv->dev = &spi->dev; priv->spi = spi; priv->delay = jiffies - usecs_to_jiffies(EL_FW_DELAY_USEC); spi_set_drvdata(spi, priv); return el15203000_probe_dt(priv); } static int el15203000_remove(struct spi_device *spi) { struct el15203000 *priv = spi_get_drvdata(spi); mutex_destroy(&priv->lock); return 0; } static const struct of_device_id el15203000_dt_ids[] = { { .compatible = "crane,el15203000", }, {}, }; MODULE_DEVICE_TABLE(of, el15203000_dt_ids); static struct spi_driver el15203000_driver = { .probe = el15203000_probe, .remove = el15203000_remove, .driver = { .name = KBUILD_MODNAME, .of_match_table = el15203000_dt_ids, }, }; module_spi_driver(el15203000_driver); MODULE_AUTHOR("Oleh Kravchenko <oleg@kaa.org.ua>"); MODULE_DESCRIPTION("el15203000 LED driver"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("spi:el15203000");