diff mbox series

[v3,4/7] drivers: leds: Add the iEi WT61P803 PUZZLE LED driver

Message ID 20200930014058.44460-5-luka.kovacic@sartura.hr (mailing list archive)
State Changes Requested
Headers show
Series Add support for the iEi Puzzle-M801 board | expand

Commit Message

Luka Kovacic Sept. 30, 2020, 1:40 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 | 157 ++++++++++++++++++++++++
 3 files changed, 166 insertions(+)
 create mode 100644 drivers/leds/leds-iei-wt61p803-puzzle.c

Comments

Pavel Machek Sept. 30, 2020, 7:48 p.m. UTC | #1 
Hi!

> +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);
> +}

Is the mutex needed? If so, should it include the
iei_wt61p803_puzzle_write_command()? Does
iei_wt61p803_puzzle_write_command() have internal locking to prevent
two messages from being mingled?

Best regards,
									Pavel
Luka Kovacic Oct. 6, 2020, 6:41 a.m. UTC | #2 
On Wed, Sep 30, 2020 at 9:48 PM Pavel Machek <pavel@ucw.cz> wrote:
>
> Hi!
>
> > +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);
> > +}
>
> Is the mutex needed? If so, should it include the
> iei_wt61p803_puzzle_write_command()? Does
> iei_wt61p803_puzzle_write_command() have internal locking to prevent
> two messages from being mingled?
>
> Best regards,
>                                                                         Pavel
>
> --
> (english) http://www.livejournal.com/~pavelmachek
> (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Hello Pavel,

The mutex isn't needed and can be removed.
The function iei_wt61p803_puzzle_write_command() already handles its own
mutex locking, so a separate mutex isn't required.

Does brightness_set_blocking only block a single caller (each caller separately)
or does it block all callers until the previous caller is finished?

Kind regards,
Luka
Luka Kovacic Oct. 7, 2020, 1:10 a.m. UTC | #3 
On Tue, Oct 6, 2020 at 8:41 AM Luka Kovacic <luka.kovacic@sartura.hr> wrote:
>
> On Wed, Sep 30, 2020 at 9:48 PM Pavel Machek <pavel@ucw.cz> wrote:
> >
> > Hi!
> >
> > > +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);
> > > +}
> >
> > Is the mutex needed? If so, should it include the
> > iei_wt61p803_puzzle_write_command()? Does
> > iei_wt61p803_puzzle_write_command() have internal locking to prevent
> > two messages from being mingled?
> >
> > Best regards,
> >                                                                         Pavel
> >
> > --
> > (english) http://www.livejournal.com/~pavelmachek
> > (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
>
> Hello Pavel,
>
> The mutex isn't needed and can be removed.
> The function iei_wt61p803_puzzle_write_command() already handles its own
> mutex locking, so a separate mutex isn't required.
>
> Does brightness_set_blocking only block a single caller (each caller separately)
> or does it block all callers until the previous caller is finished?
>
> Kind regards,
> Luka

Hello Pavel,

I've sent out a new patchset, but I kept the mutex in use.
It's used to make sure only one read or write request is done at once,
when writing
to the LED driver private structure.

I have also added this description to the struct comment.

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..b5822a835116
--- /dev/null
+++ b/drivers/leds/leds-iei-wt61p803-puzzle.c
@@ -0,0 +1,157 @@ 
+// 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 for LED operations
+ * @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");