Re: [PATCH/RFC v9 05/19] leds: Add support for max77693 mfd flash cell

[Sakari Ailus]

Hi Jacek,

On Thu, Dec 04, 2014 at 12:06:59PM +0100, Jacek Anaszewski wrote:
> Hi Sakari,
> 
> Thanks for the review.

You're welcome! :-)

> On 12/04/2014 10:39 AM, Sakari Ailus wrote:
> >Hi Jacek,
> >
> >On Wed, Dec 03, 2014 at 05:06:40PM +0100, Jacek Anaszewski wrote:
> >>This patch adds led-flash support to Maxim max77693 chipset.
> >>A device can be exposed to user space through LED subsystem
> >>sysfs interface. Device supports up to two leds which can
> >>work in flash and torch mode. The leds can be triggered
> >>externally or by software.
> >>
> >>Signed-off-by: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
> >>Signed-off-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
> >>Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> >>Cc: Bryan Wu <cooloney@xxxxxxxxx>
> >>Cc: Richard Purdie <rpurdie@xxxxxxxxx>
> >>Cc: Lee Jones <lee.jones@xxxxxxxxxx>
> >>Cc: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
> >>---
> >>  drivers/leds/Kconfig         |   10 +
> >>  drivers/leds/Makefile        |    1 +
> >>  drivers/leds/leds-max77693.c | 1023 ++++++++++++++++++++++++++++++++++++++++++
> >>  3 files changed, 1034 insertions(+)
> >>  create mode 100644 drivers/leds/leds-max77693.c
> >>
> >>diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> >>index fa8021e..2e66d55 100644
> >>--- a/drivers/leds/Kconfig
> >>+++ b/drivers/leds/Kconfig
> >>@@ -463,6 +463,16 @@ config LEDS_TCA6507
> >>  	  LED driver chips accessed via the I2C bus.
> >>  	  Driver support brightness control and hardware-assisted blinking.
> >>
> >>+config LEDS_MAX77693
> >>+	tristate "LED support for MAX77693 Flash"
> >>+	depends on LEDS_CLASS_FLASH
> >>+	depends on MFD_MAX77693
> >>+	depends on OF
> >>+	help
> >>+	  This option enables support for the flash part of the MAX77693
> >>+	  multifunction device. It has build in control for two leds in flash
> >>+	  and torch mode.
> >>+
> >>  config LEDS_MAX8997
> >>  	tristate "LED support for MAX8997 PMIC"
> >>  	depends on LEDS_CLASS && MFD_MAX8997
> >>diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> >>index cbba921..57ca62b 100644
> >>--- a/drivers/leds/Makefile
> >>+++ b/drivers/leds/Makefile
> >>@@ -52,6 +52,7 @@ obj-$(CONFIG_LEDS_MC13783)		+= leds-mc13783.o
> >>  obj-$(CONFIG_LEDS_NS2)			+= leds-ns2.o
> >>  obj-$(CONFIG_LEDS_NETXBIG)		+= leds-netxbig.o
> >>  obj-$(CONFIG_LEDS_ASIC3)		+= leds-asic3.o
> >>+obj-$(CONFIG_LEDS_MAX77693)		+= leds-max77693.o
> >>  obj-$(CONFIG_LEDS_MAX8997)		+= leds-max8997.o
> >>  obj-$(CONFIG_LEDS_LM355x)		+= leds-lm355x.o
> >>  obj-$(CONFIG_LEDS_BLINKM)		+= leds-blinkm.o
> >>diff --git a/drivers/leds/leds-max77693.c b/drivers/leds/leds-max77693.c
> >>new file mode 100644
> >>index 0000000..67a2f8f
> >>--- /dev/null
> >>+++ b/drivers/leds/leds-max77693.c
> >>@@ -0,0 +1,1023 @@
> >>+/*
> >>+ * LED Flash class driver for the flash cell of max77693 mfd.
> >>+ *
> >>+ *	Copyright (C) 2014, Samsung Electronics Co., Ltd.
> >>+ *
> >>+ *	Authors: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
> >>+ *		 Andrzej Hajda <a.hajda@xxxxxxxxxxx>
> >>+ *
> >>+ * This program is free software; you can redistribute it and/or
> >>+ * modify it under the terms of the GNU General Public License
> >>+ * version 2 as published by the Free Software Foundation.
> >>+ */
> >>+
> >>+#include <asm/div64.h>
> >>+#include <linux/led-class-flash.h>
> >>+#include <linux/mfd/max77693.h>
> >>+#include <linux/mfd/max77693-private.h>
> >>+#include <linux/module.h>
> >>+#include <linux/mutex.h>
> >>+#include <linux/platform_device.h>
> >>+#include <linux/regmap.h>
> >>+#include <linux/slab.h>
> >>+#include <linux/workqueue.h>
> >>+
> >>+#define MODE_OFF		0
> >>+#define MODE_FLASH1		(1 << 0)
> >>+#define MODE_FLASH2		(1 << 1)
> >>+#define MODE_TORCH1		(1 << 2)
> >>+#define MODE_TORCH2		(1 << 3)
> >>+#define MODE_FLASH_EXTERNAL1	(1 << 4)
> >>+#define MODE_FLASH_EXTERNAL2	(1 << 5)
> >
> >You could do this based on an argument (led number). E.g.
> >
> >#define MODE_FLASH_EXTERNAL(a)	(1 << (4 + a))
> 
> OK.
> 
> >>+#define MODE_FLASH		(MODE_FLASH1 | MODE_FLASH2 | \
> >>+				 MODE_FLASH_EXTERNAL1 | MODE_FLASH_EXTERNAL2)
> >>+
> >>+#define FLED1_IOUT		(1 << 0)
> >>+#define FLED2_IOUT		(1 << 1)
> >>+
> >>+enum {
> >>+	FLED1,
> >>+	FLED2
> >>+};
> >>+
> >>+enum {
> >>+	FLASH,
> >>+	TORCH
> >>+};
> >>+
> >>+struct max77693_sub_led {

This could then be renamed as "max77693_led"; up to you.

> >>+	struct led_classdev_flash ldev;
> >>+	struct work_struct work_brightness_set;
> >>+
> >>+	unsigned int torch_brightness;
> >>+	unsigned int flash_timeout;
> >>+};
> >>+
> >>+struct max77693_led {
> >
> >As this does not refer to a device, how about struct max77693_device, for
> >instance?
> 
> OK.
> 
> >>+	struct regmap *regmap;
> >>+	struct platform_device *pdev;
> >>+	struct max77693_led_platform_data *pdata;
> >>+	struct mutex lock;
> >>+
> >>+	struct max77693_sub_led sub_leds[2];
> >>+
> >>+	unsigned int current_flash_timeout;
> >>+	unsigned int mode_flags;
> >>+	u8 torch_iout_reg;
> >>+	bool iout_joint;
> >>+	int strobing_sub_led_id;
> >>+};
> >>+
> >>+struct max77693_led_settings {
> >>+	struct led_flash_setting torch_brightness;
> >>+	struct led_flash_setting flash_brightness;
> >>+	struct led_flash_setting flash_timeout;
> >>+};
> >>+
> >>+static u8 max77693_led_iout_to_reg(u32 ua)
> >>+{
> >>+	if (ua < FLASH_IOUT_MIN)
> >>+		ua = FLASH_IOUT_MIN;
> >>+	return (ua - FLASH_IOUT_MIN) / FLASH_IOUT_STEP;
> >>+}
> >>+
> >>+static u8 max77693_flash_timeout_to_reg(u32 us)
> >>+{
> >>+	return (us - FLASH_TIMEOUT_MIN) / FLASH_TIMEOUT_STEP;
> >>+}
> >>+
> >>+static inline struct max77693_led *ldev1_to_led(
> >>+					struct led_classdev_flash *ldev)
> >>+{
> >>+	struct max77693_sub_led *sub_led = container_of(ldev,
> >>+						struct max77693_sub_led,
> >>+						ldev);
> >>+	return container_of(sub_led, struct max77693_led, sub_leds[0]);
> >
> >You could have a common macro to find the flash controller struct if you add
> >the LED number to struct max77693_sub_led.
> >
> >>+}
> >>+
> >>+static inline struct max77693_led *ldev2_to_led(
> >>+					struct led_classdev_flash *ldev)
> >>+{
> >>+	struct max77693_sub_led *sub_led = container_of(ldev,
> >>+						struct max77693_sub_led,
> >>+						ldev);
> >>+	return container_of(sub_led, struct max77693_led, sub_leds[1]);
> >>+}
> >>+
> >>+static u8 max77693_led_vsys_to_reg(u32 mv)
> >>+{
> >>+	return ((mv - MAX_FLASH1_VSYS_MIN) / MAX_FLASH1_VSYS_STEP) << 2;
> >>+}
> >>+
> >>+static u8 max77693_led_vout_to_reg(u32 mv)
> >>+{
> >>+	return (mv - FLASH_VOUT_MIN) / FLASH_VOUT_STEP + FLASH_VOUT_RMIN;
> >>+}
> >>+
> >>+/* split composite current @i into two @iout according to @imax weights */
> >
> >What do you intend to do in the oint iout mode? A single LED connected to
> >iout pins which are soldered together?
> 
> Exactly that what is written in the comment - split the current into
> both outputs.

I think we discussed this on #v4l --- was it so that both outputs, if
they're connected, should have the same current if there's a single LED
connected to them?

...

> >>+static int max77693_led_parse_dt(struct max77693_led *led,
> >>+				struct device_node *node)
> >>+{
> >>+	struct max77693_led_platform_data *p = led->pdata;
> >>+	struct device *dev = &led->pdev->dev;
> >>+	struct device_node *child_node;
> >>+	u32 fled_id;
> >>+	int ret;
> >>+
> >>+	of_property_read_u32_array(node, "maxim,fleds", p->fleds, 2);
> >>+	of_property_read_u32_array(node, "maxim,trigger", p->trigger, 2);
> >>+	of_property_read_u32_array(node, "maxim,trigger-type", p->trigger_type,
> >>+									2);
> >>+	of_property_read_u32(node, "maxim,boost-mode", &p->boost_mode);
> >>+	of_property_read_u32(node, "maxim,boost-vout", &p->boost_vout);
> >>+	of_property_read_u32(node, "maxim,vsys-min", &p->low_vsys);
> >>+
> >>+	for_each_available_child_of_node(node, child_node) {
> >>+		ret = of_property_read_u32(child_node, "maxim,fled_id",
> >>+						&fled_id);
> >>+		if (ret < 0) {
> >>+			dev_err(dev, "Error reading \"fled_id\" DT property\n");
> >>+			return ret;
> >>+		}
> >>+
> >>+		fled_id = clamp_val(fled_id, 1, 2);
> >
> >I think you should check fled_id is really correct, and not clamp it.
> 
> Right.
> 
> >>+		--fled_id;
> >>+
> >>+		p->sub_nodes[fled_id] = child_node;
> >
> >p->sub_nodes is not accessed anywhere else. Do you plan to use it for
> >something?
> 
> It is passed to v4l2_flash_init. In this patch set I add the V4L2
> support in the separate patch. Probably this should be move there.

Ok. I'm ok to keep it here as well, up to you.

-- 
Regards,

Sakari Ailus
e-mail: sakari.ailus@xxxxxx	XMPP: sailus@xxxxxxxxxxxxxx
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