diff mbox series

[v4,4/6] drivers: leds: Add the iEi WT61P803 PUZZLE LED driver

Message ID 20201007004901.39859-5-luka.kovacic@sartura.hr
State Superseded
Headers show
Series Add support for the iEi WT61P803 PUZZLE MCU | expand

Commit Message

Luka Kovacic Oct. 7, 2020, 12:48 a.m. UTC 
Add support for the iEi WT61P803 PUZZLE LED driver.
Currently only the front panel power LED is supported.

This driver depends on the iEi WT61P803 PUZZLE MFD driver.

Signed-off-by: Luka Kovacic <luka.kovacic@sartura.hr>
Cc: Luka Perkov <luka.perkov@sartura.hr>
Cc: Robert Marko <robert.marko@sartura.hr>
---
 drivers/leds/Kconfig                    |   8 ++
 drivers/leds/Makefile                   |   1 +
 drivers/leds/leds-iei-wt61p803-puzzle.c | 156 ++++++++++++++++++++++++
 3 files changed, 165 insertions(+)
 create mode 100644 drivers/leds/leds-iei-wt61p803-puzzle.c

Comments

Pavel Machek Oct. 7, 2020, 11:27 a.m. UTC | #1 
Hi!

> Add support for the iEi WT61P803 PUZZLE LED driver.

> Currently only the front panel power LED is supported.

> 

> This driver depends on the iEi WT61P803 PUZZLE MFD driver.


> +static int iei_wt61p803_puzzle_led_brightness_set_blocking(struct led_classdev *cdev,

> +							   enum led_brightness brightness)

> +{

> +	struct iei_wt61p803_puzzle_led *priv = cdev_to_iei_wt61p803_puzzle_led(cdev);

> +	unsigned char *resp_buf = priv->response_buffer;

> +	unsigned char led_power_cmd[5] = {

> +		IEI_WT61P803_PUZZLE_CMD_HEADER_START,

> +		IEI_WT61P803_PUZZLE_CMD_LED,

> +		IEI_WT61P803_PUZZLE_CMD_LED_POWER,

> +		(char)IEI_LED_OFF

> +	};

> +	size_t reply_size;

> +

> +	mutex_lock(&priv->lock);

> +	if (brightness == LED_OFF) {

> +		led_power_cmd[3] = (char)IEI_LED_OFF;

> +		priv->led_power_state = LED_OFF;

> +	} else {

> +		led_power_cmd[3] = (char)IEI_LED_ON;

> +		priv->led_power_state = LED_ON;

> +	}

> +	mutex_unlock(&priv->lock);


Are you sure you need the mutex?

> +	ret = devm_led_classdev_register_ext(dev, &priv->cdev, &init_data);

> +	if (ret) {

> +		dev_err(dev, "Could not register LED\n");

> +		goto err_child_node;

> +	}

> +	return 0;

> +err_child_node:

> +	fwnode_handle_put(child);

> +	return ret;

> +}


Is the fwnode_handle_put(child); missing in non-error path somewhere?

> +MODULE_LICENSE("GPL");


Make sure this is consistent with file header. GPLv2+, if you can.

Best regards,

									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
Luka Kovacic Oct. 9, 2020, 11:25 p.m. UTC | #2 
On Wed, Oct 7, 2020 at 1:27 PM Pavel Machek <pavel@ucw.cz> wrote:
>
> Hi!
>
> > Add support for the iEi WT61P803 PUZZLE LED driver.
> > Currently only the front panel power LED is supported.
> >
> > This driver depends on the iEi WT61P803 PUZZLE MFD driver.
>
> > +static int iei_wt61p803_puzzle_led_brightness_set_blocking(struct led_classdev *cdev,
> > +                                                        enum led_brightness brightness)
> > +{
> > +     struct iei_wt61p803_puzzle_led *priv = cdev_to_iei_wt61p803_puzzle_led(cdev);
> > +     unsigned char *resp_buf = priv->response_buffer;
> > +     unsigned char led_power_cmd[5] = {
> > +             IEI_WT61P803_PUZZLE_CMD_HEADER_START,
> > +             IEI_WT61P803_PUZZLE_CMD_LED,
> > +             IEI_WT61P803_PUZZLE_CMD_LED_POWER,
> > +             (char)IEI_LED_OFF
> > +     };
> > +     size_t reply_size;
> > +
> > +     mutex_lock(&priv->lock);
> > +     if (brightness == LED_OFF) {
> > +             led_power_cmd[3] = (char)IEI_LED_OFF;
> > +             priv->led_power_state = LED_OFF;
> > +     } else {
> > +             led_power_cmd[3] = (char)IEI_LED_ON;
> > +             priv->led_power_state = LED_ON;
> > +     }
> > +     mutex_unlock(&priv->lock);
>
> Are you sure you need the mutex?
>
> > +     ret = devm_led_classdev_register_ext(dev, &priv->cdev, &init_data);
> > +     if (ret) {
> > +             dev_err(dev, "Could not register LED\n");
> > +             goto err_child_node;
> > +     }
> > +     return 0;
> > +err_child_node:
> > +     fwnode_handle_put(child);
> > +     return ret;
> > +}
>
> Is the fwnode_handle_put(child); missing in non-error path somewhere?
>
> > +MODULE_LICENSE("GPL");
>
> Make sure this is consistent with file header. GPLv2+, if you can.
>
> Best regards,
>
>                                                                         Pavel
> --
> (english) http://www.livejournal.com/~pavelmachek
> (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Hi Pavel,

The mutex is locked in
iei_wt61p803_puzzle_led_brightness_set_blocking(), as concurrent
access to the same private structure member should be possible, when
reading the state
from iei_wt61p803_puzzle_led_brightness_get().

It does look like I missed the final fwnode_handle_put(child) here.

My understanding regarding the license is that when
MODULE_LICENSE("GPL") is used
the SPDX identifier can either be GPL-2.0-only or GPL-2.0-or-later.

Kind regards,
Luka
diff mbox series

Patch

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 1c181df24eae..8a25fb753dec 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -332,6 +332,14 @@  config LEDS_IPAQ_MICRO
 	  Choose this option if you want to use the notification LED on
 	  Compaq/HP iPAQ h3100 and h3600.
 
+config LEDS_IEI_WT61P803_PUZZLE
+	tristate "LED Support for the iEi WT61P803 PUZZLE MCU"
+	depends on LEDS_CLASS
+	depends on MFD_IEI_WT61P803_PUZZLE
+	help
+	  This option enables support for LEDs controlled by the iEi WT61P803
+	  M801 MCU.
+
 config LEDS_HP6XX
 	tristate "LED Support for the HP Jornada 6xx"
 	depends on LEDS_CLASS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index c2c7d7ade0d0..cd362437fefd 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -34,6 +34,7 @@  obj-$(CONFIG_LEDS_HP6XX)		+= leds-hp6xx.o
 obj-$(CONFIG_LEDS_INTEL_SS4200)		+= leds-ss4200.o
 obj-$(CONFIG_LEDS_IP30)			+= leds-ip30.o
 obj-$(CONFIG_LEDS_IPAQ_MICRO)		+= leds-ipaq-micro.o
+obj-$(CONFIG_LEDS_IEI_WT61P803_PUZZLE)	+= leds-iei-wt61p803-puzzle.o
 obj-$(CONFIG_LEDS_IS31FL319X)		+= leds-is31fl319x.o
 obj-$(CONFIG_LEDS_IS31FL32XX)		+= leds-is31fl32xx.o
 obj-$(CONFIG_LEDS_KTD2692)		+= leds-ktd2692.o
diff --git a/drivers/leds/leds-iei-wt61p803-puzzle.c b/drivers/leds/leds-iei-wt61p803-puzzle.c
new file mode 100644
index 000000000000..9c5d5c6b4502
--- /dev/null
+++ b/drivers/leds/leds-iei-wt61p803-puzzle.c
@@ -0,0 +1,156 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/* iEi WT61P803 PUZZLE MCU LED Driver
+ *
+ * Copyright (C) 2020 Sartura Ltd.
+ * Author: Luka Kovacic <luka.kovacic@sartura.hr>
+ */
+
+#include <linux/leds.h>
+#include <linux/mfd/iei-wt61p803-puzzle.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+
+enum iei_wt61p803_puzzle_led_state {
+	IEI_LED_OFF = 0x30,
+	IEI_LED_ON = 0x31,
+	IEI_LED_BLINK_5HZ = 0x32,
+	IEI_LED_BLINK_1HZ = 0x33,
+};
+
+/**
+ * struct iei_wt61p803_puzzle_led - MCU LED Driver
+ *
+ * @mcu:		MCU struct pointer
+ * @response_buffer	Global MCU response buffer allocation
+ * @lock:		General mutex lock to protect simultaneous R/W access to led_power_state
+ * @led_power_state:	State of the front panel power LED
+ * @cdev:		LED classdev
+ */
+struct iei_wt61p803_puzzle_led {
+	struct iei_wt61p803_puzzle *mcu;
+	unsigned char *response_buffer;
+	struct mutex lock;
+	int led_power_state;
+	struct led_classdev cdev;
+};
+
+static inline struct iei_wt61p803_puzzle_led *cdev_to_iei_wt61p803_puzzle_led
+	(struct led_classdev *led_cdev)
+{
+	return dev_get_drvdata(led_cdev->dev->parent);
+}
+
+static int iei_wt61p803_puzzle_led_brightness_set_blocking(struct led_classdev *cdev,
+							   enum led_brightness brightness)
+{
+	struct iei_wt61p803_puzzle_led *priv = cdev_to_iei_wt61p803_puzzle_led(cdev);
+	unsigned char *resp_buf = priv->response_buffer;
+	unsigned char led_power_cmd[5] = {
+		IEI_WT61P803_PUZZLE_CMD_HEADER_START,
+		IEI_WT61P803_PUZZLE_CMD_LED,
+		IEI_WT61P803_PUZZLE_CMD_LED_POWER,
+		(char)IEI_LED_OFF
+	};
+	size_t reply_size;
+
+	mutex_lock(&priv->lock);
+	if (brightness == LED_OFF) {
+		led_power_cmd[3] = (char)IEI_LED_OFF;
+		priv->led_power_state = LED_OFF;
+	} else {
+		led_power_cmd[3] = (char)IEI_LED_ON;
+		priv->led_power_state = LED_ON;
+	}
+	mutex_unlock(&priv->lock);
+
+	return iei_wt61p803_puzzle_write_command(priv->mcu, led_power_cmd,
+			sizeof(led_power_cmd), resp_buf, &reply_size);
+}
+
+static enum led_brightness
+iei_wt61p803_puzzle_led_brightness_get(struct led_classdev *cdev)
+{
+	struct iei_wt61p803_puzzle_led *priv =
+		cdev_to_iei_wt61p803_puzzle_led(cdev);
+	int led_state;
+
+	mutex_lock(&priv->lock);
+	led_state = priv->led_power_state;
+	mutex_unlock(&priv->lock);
+
+	return led_state;
+}
+
+static int iei_wt61p803_puzzle_led_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct iei_wt61p803_puzzle *mcu = dev_get_drvdata(dev->parent);
+	struct iei_wt61p803_puzzle_led *priv;
+	struct led_init_data init_data = {};
+	struct fwnode_handle *child;
+	int ret;
+	u32 reg;
+
+	if (device_get_child_node_count(dev) != 1)
+		return -EINVAL;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->response_buffer = devm_kzalloc(dev, IEI_WT61P803_PUZZLE_BUF_SIZE, GFP_KERNEL);
+	if (!priv->response_buffer)
+		return -ENOMEM;
+
+	priv->mcu = mcu;
+	priv->led_power_state = 1;
+	mutex_init(&priv->lock);
+	dev_set_drvdata(dev, priv);
+
+	child = device_get_next_child_node(dev, NULL);
+
+	ret = fwnode_property_read_u32(child, "reg", &reg);
+	if (ret || reg > 1) {
+		dev_err(dev, "Could not register 'reg' (%lu)\n", (unsigned long)reg);
+		ret = -EINVAL;
+		goto err_child_node;
+	}
+
+	priv->cdev.brightness_set_blocking = iei_wt61p803_puzzle_led_brightness_set_blocking;
+	priv->cdev.brightness_get = iei_wt61p803_puzzle_led_brightness_get;
+	priv->cdev.max_brightness = 1;
+	init_data.fwnode = child;
+
+	ret = devm_led_classdev_register_ext(dev, &priv->cdev, &init_data);
+	if (ret) {
+		dev_err(dev, "Could not register LED\n");
+		goto err_child_node;
+	}
+	return 0;
+err_child_node:
+	fwnode_handle_put(child);
+	return ret;
+}
+
+static const struct of_device_id iei_wt61p803_puzzle_led_of_match[] = {
+	{ .compatible = "iei,wt61p803-puzzle-leds" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, iei_wt61p803_puzzle_led_of_match);
+
+static struct platform_driver iei_wt61p803_puzzle_led_driver = {
+	.driver = {
+		.name = "iei-wt61p803-puzzle-led",
+		.of_match_table = iei_wt61p803_puzzle_led_of_match,
+	},
+	.probe = iei_wt61p803_puzzle_led_probe,
+};
+module_platform_driver(iei_wt61p803_puzzle_led_driver);
+
+MODULE_DESCRIPTION("iEi WT61P803 PUZZLE front panel LED driver");
+MODULE_AUTHOR("Luka Kovacic <luka.kovacic@sartura.hr>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:leds-iei-wt61p803-puzzle");