Hi Oleh,
On 9/5/19 8:17 AM, Oleh Kravchenko wrote:
> Hello Jacek,
> Few question from my side just for better understanding :)
>
>> 5 вер. 2019 р. о 12:23 дп Jacek Anaszewski <jacek.anaszewski@xxxxxxxxx> написав(ла):
>>
>> Hi Oleh,
>>
>> Thank you for the updated set.
>>
>> Now it looks really good. Just few minor issues left.
>>
>> And side note - please address the patches also to maintainers,
>> not only to the list.
>>
>> On 8/31/19 12:46 AM, Oleh Kravchenko wrote:
>>> This patch adds a LED class driver for the RGB LEDs found on
>>> the Crane Merchandising System EL15203000 LEDs board
>>> (aka RED LEDs board).
>>>
>>> Signed-off-by: Oleh Kravchenko <oleg@xxxxxxxxxx>
>>> ---
>>> .../testing/sysfs-class-led-driver-el15203000 | 22 ++
>>> drivers/leds/Kconfig | 13 +
>>> drivers/leds/Makefile | 1 +
>>> drivers/leds/leds-el15203000.c | 362 ++++++++++++++++++
>>> 4 files changed, 398 insertions(+)
>>> create mode 100644 Documentation/ABI/testing/sysfs-class-led-driver-el15203000
>>> create mode 100644 drivers/leds/leds-el15203000.c
>>>
>>> diff --git a/Documentation/ABI/testing/sysfs-class-led-driver-el15203000 b/Documentation/ABI/testing/sysfs-class-led-driver-el15203000
>>> new file mode 100644
>>> index 000000000000..767763409125
>>> --- /dev/null
>>> +++ b/Documentation/ABI/testing/sysfs-class-led-driver-el15203000
>>> @@ -0,0 +1,22 @@
>>> +What: /sys/class/leds/<led>/hw_pattern
>>> +Date: August 2019
>>> +KernelVersion: 5.3
>>
>> Now it will be September and 5.5. It is late even for 5.4.
>
> Here should month of patch creation or when it will be reviewed? :)
> Because I sent in 31 August.
It should reflect the kernel version in which the ABI is supposed to
appear.
>>> +Description:
>>> + Specify a hardware pattern for the EL15203000 LED.
>>> + The LEDs board supports only predefined patterns by firmware
>>> + for specific LEDs.
>>> +
>>> + Breathing mode for Screen frame light tube:
>>> + "0 4000 1 4000"
>>> +
>>> + Cascade mode for Pipe LED:
>>> + "1 800 2 800 4 800 8 800 16 800"
>>> +
>>> + Inverted cascade mode for Pipe LED:
>>> + "30 800 29 800 27 800 23 800 15 800"
>>> +
>>> + Bounce mode for Pipe LED:
>>> + "1 800 2 800 4 800 8 800 16 800 16 800 8 800 4 800 2 800 1 800"
>>> +
>>> + Inverted bounce mode for Pipe LED:
>>> + "30 800 29 800 27 800 23 800 15 800 15 800 23 800 27 800 29 800 30 800"
>>> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
>>> index 1988de1d64c0..6e7703fd03d0 100644
>>> --- a/drivers/leds/Kconfig
>>> +++ b/drivers/leds/Kconfig
>>> @@ -132,6 +132,19 @@ config LEDS_CR0014114
>>> To compile this driver as a module, choose M here: the module
>>> will be called leds-cr0014114.
>>>
>>> +config LEDS_EL15203000
>>> + tristate "LED Support for Crane EL15203000"
>>> + depends on LEDS_CLASS
>>> + depends on SPI
>>> + depends on OF
>>> + help
>>> + This option enables support for EL15203000 LED Board
>>> + (aka RED LED board) which is widely used in coffee vending
>>> + machines produced by Crane Merchandising Systems.
>>> +
>>> + To compile this driver as a module, choose M here: the module
>>> + will be called leds-el15203000.
>>> +
>>> config LEDS_LM3530
>>> tristate "LCD Backlight driver for LM3530"
>>> depends on LEDS_CLASS
>>> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
>>> index 41fb073a39c1..2da39e896ce8 100644
>>> --- a/drivers/leds/Makefile
>>> +++ b/drivers/leds/Makefile
>>> @@ -89,6 +89,7 @@ obj-$(CONFIG_LEDS_LM36274) += leds-lm36274.o
>>> # LED SPI Drivers
>>> obj-$(CONFIG_LEDS_CR0014114) += leds-cr0014114.o
>>> obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o
>>> +obj-$(CONFIG_LEDS_EL15203000) += leds-el15203000.o
>>>
>>> # LED Userspace Drivers
>>> obj-$(CONFIG_LEDS_USER) += uleds.o
>>> diff --git a/drivers/leds/leds-el15203000.c b/drivers/leds/leds-el15203000.c
>>> new file mode 100644
>>> index 000000000000..9de81dee3618
>>> --- /dev/null
>>> +++ b/drivers/leds/leds-el15203000.c
>>> @@ -0,0 +1,362 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +// Copyright (c) 2019 Crane Merchandising Systems. All rights reserved.
>>> +// Copyright (C) 2019 Oleh Kravchenko <oleg@xxxxxxxxxx>
>>> +
>>> +#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;
>>> + u8 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;
>>> + }
>>
>> Nice!
>>
>>> +
>>> + 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 = container_of(ldev,
>>> + struct el15203000_led,
>>> + ldev);
>>> +
>>> + if (repeat > 0)
>>
>> This is wrong. Repeat has to be -1 or > 0. If all patterns supported
>> by your device are infinite, then you should expect here -1.
>
> Ok, then we have bug in led pattern trigger.
> echo -1 > /…/repeat doesn’t work as expected and return error.
> So if I tried to change repeat from sysfs, it will never be -1 again.
Yes, I see now that we probably have a bug in repeat_store()
in drivers/leds/trigger/ledtrig-pattern.c.. It assumes that we have
already some pattern tuples defined and works properly only then.
It is not prepared for a case when we want to set repeat count
before defining the pattern and attempts to immediately start
pattern via pattern_trig_start_pattern(), which returns error
when no proper pattern is defined.
To fix that we could perhaps attempt to (re)start pattern in
repeat_store() only if data->npatterns > 0. It would be even
consequent with what we have there already few lines above
where led_cdev->pattern_clear(led_cdev) is guarded similarly.
>>
>> Either way this needs to be covered in the ABI documentation too.
>>
>>> + return -EINVAL;
>>> +
>>> + if (is_cascade(pattern, len, false, false)) {
>>> + dev_dbg(led->priv->dev, "Cascade mode for 0x%02x(%c)",
>>> + led->reg, led->reg);
>>> +
>>> + return el15203000_cmd(led, 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);
>>> +
>>> + return el15203000_cmd(led, 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);
>>> +
>>> + return el15203000_cmd(led, 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);
>>> +
>>> + return el15203000_cmd(led, EL_PIPE_INV_BOUNCE);
>>> + }
>>> +
>>> + return -EINVAL;
>>> +}
>>> +
>>> +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)
>>> +{
>>> + size_t i = 0;
>>> + struct el15203000_led *led;
>>> + struct fwnode_handle *child;
>>> + int ret;
>>> + u32 reg;
>>> + struct led_init_data init_data = {};
>>> +
>>> + device_for_each_child_node(priv->dev, child) {
>>
>> Please move above init_data initialization here.
>
> No problem.
>
>>
>>
>>> + led = &priv->leds[i];
>>
>> You can increment 'i' here, it is not used below and you will save one
>> LOC:
>>
>> led = &priv->leds[i++];
>
> Agree.
>
>>
>>> +
>>> + init_data.fwnode = child;
>>
>> Please move it to where it will be needed. i.e. one line above
>> devm_led_classdev_register_ext().
>
> Will do.
>
>>
>>> +
>>> + ret = fwnode_property_read_u32(child, "reg", ®);
>>> + if (ret) {
>>> + dev_err(priv->dev, "LED without ID number");
>>> + fwnode_handle_put(child);
>>> +
>>> + return ret;
>>> + }
>>> +
>>> + if (reg > U8_MAX) {
>>> + dev_err(priv->dev, "LED value %d is invalid", reg);
>>> + fwnode_handle_put(child);
>>> +
>>> + return -EINVAL;
>>> + }
>>> +
>>> + led->reg = reg;
>>
>> I'd just pass &led->reg directly to fwnode_property_read_u32().
>> Then you'll be able to drop local reg variable.
>
> For this device/driver reg value is just one byte
> You are ok to waste 3 bytes for every EL15203000 LED?
You're wasting them anyway due to alignment. If you really
cared about that you could add __packed modifier
to the struct definition but I don't think it makes
big difference in this case.
>>
>>> +
>>> + 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 (reg == 'S') {
>>> + led->ldev.pattern_set = el15203000_pattern_set_S;
>>> + led->ldev.pattern_clear = el15203000_pattern_clear;
>>> + } else if (reg == 'P') {
>>> + led->ldev.pattern_set = el15203000_pattern_set_P;
>>> + led->ldev.pattern_clear = el15203000_pattern_clear;
>>> + }
>>> +
>>> + 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);
>>> +
>>> + return ret;
>>> + }
>>> +
>>> + i++;
>>> + }
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static int el15203000_probe(struct spi_device *spi)
>>> +{
>>> + struct el15203000 *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, 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);
>>> +
>>> + ret = el15203000_probe_dt(priv);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + spi_set_drvdata(spi, priv);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +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@xxxxxxxxxx>");
>>> +MODULE_DESCRIPTION("el15203000 LED driver");
>>> +MODULE_LICENSE("GPL v2");
>>> +MODULE_ALIAS("spi:el15203000");
>>>
>>
>> --
>> Best regards,
>> Jacek Anaszewski
>
--
Best regards,
Jacek Anaszewski
