// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2019 Crane Merchandising Systems. All rights reserved.
// Copyright (C) 2019 Oleh Kravchenko <[email protected]>
#include <linux/delay.h>
#include <linux/leds.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/property.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 led_classdev ldev;
struct el15203000 *priv;
u32 reg;
};
struct el15203000 {
struct device *dev;
struct mutex lock;
struct spi_device *spi;
unsigned long delay;
size_t count;
struct el15203000_led leds[] __counted_by(count);
};
#define to_el15203000_led(d) container_of(d, struct el15203000_led, ldev)
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 = to_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 = to_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)
{
struct el15203000_led *led = to_el15203000_led(ldev);
u8 cmd;
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 = to_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");
goto err_child_out;
}
if (led->reg > U8_MAX) {
dev_err(priv->dev, "LED value %d is invalid", led->reg);
ret = -EINVAL;
goto err_child_out;
}
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);
goto err_child_out;
}
led++;
}
return 0;
err_child_out:
fwnode_handle_put(child);
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 void el15203000_remove(struct spi_device *spi)
{
struct el15203000 *priv = spi_get_drvdata(spi);
mutex_destroy(&priv->lock);
}
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 <[email protected]>");
MODULE_DESCRIPTION("el15203000 LED driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("spi:el15203000");
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