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Date: Sat, 22 Jun 2024 13:55:25 +0200
From: André Apitzsch <git@...tzsch.eu>
To: Lee Jones <lee@...nel.org>
Cc: Pavel Machek <pavel@....cz>, Rob Herring <robh@...nel.org>, Krzysztof
Kozlowski <krzysztof.kozlowski+dt@...aro.org>, Conor Dooley
<conor+dt@...nel.org>, "Gustavo A. R. Silva" <gustavoars@...nel.org>, Bjorn
Andersson <andersson@...nel.org>, Konrad Dybcio <konrad.dybcio@...aro.org>,
Christophe JAILLET <christophe.jaillet@...adoo.fr>, Trilok Soni
<quic_tsoni@...cinc.com>, Kees Cook <kees@...nel.org>,
linux-leds@...r.kernel.org, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-hardening@...r.kernel.org,
linux-arm-msm@...r.kernel.org, ~postmarketos/upstreaming@...ts.sr.ht,
phone-devel@...r.kernel.org
Subject: Re: [PATCH v4 2/3] leds: sy7802: Add support for Silergy SY7802
flash LED controller
Hello Lee,
Am Freitag, dem 21.06.2024 um 11:26 +0100 schrieb Lee Jones:
> On Sun, 16 Jun 2024, André Apitzsch via B4 Relay wrote:
>
> > From: André Apitzsch <git@...tzsch.eu>
> >
> > The SY7802 is a current-regulated charge pump which can regulate
> > two
> > current levels for Flash and Torch modes.
> >
> > It is a high-current synchronous boost converter with 2-channel
> > high
> > side current sources. Each channel is able to deliver 900mA
> > current.
> >
> > Signed-off-by: André Apitzsch <git@...tzsch.eu>
> > ---
> > drivers/leds/flash/Kconfig | 11 +
> > drivers/leds/flash/Makefile | 1 +
> > drivers/leds/flash/leds-sy7802.c | 542
> > +++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 554 insertions(+)
>
> Generally very nice.
>
> Just a couple of teensy nits to fix then add my and resubmit please.
>
> Acked-by: Lee Jones <lee@...nel.org>
>
> > [...]
> > diff --git a/drivers/leds/flash/leds-sy7802.c
> > b/drivers/leds/flash/leds-sy7802.c
> > new file mode 100644
> > index 000000000000..c4bea55a62d0
> > --- /dev/null
> > +++ b/drivers/leds/flash/leds-sy7802.c
> > @@ -0,0 +1,542 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * Silergy SY7802 flash LED driver with I2C interface
>
> "an I2C interface"
>
> Or
>
> "I2C interfaces"
>
> > + * Copyright 2024 André Apitzsch <git@...tzsch.eu>
> > + */
> > +
> > +#include <linux/gpio/consumer.h>
> > +#include <linux/i2c.h>
> > +#include <linux/kernel.h>
> > +#include <linux/led-class-flash.h>
> > +#include <linux/module.h>
> > +#include <linux/mutex.h>
> > +#include <linux/regmap.h>
> > +#include <linux/regulator/consumer.h>
> > +
> > +#define SY7802_MAX_LEDS 2
> > +#define SY7802_LED_JOINT 2
> > +
> > +#define SY7802_REG_ENABLE 0x10
> > +#define SY7802_REG_TORCH_BRIGHTNESS 0xa0
> > +#define SY7802_REG_FLASH_BRIGHTNESS 0xb0
> > +#define SY7802_REG_FLASH_DURATION 0xc0
> > +#define SY7802_REG_FLAGS 0xd0
> > +#define SY7802_REG_CONFIG_1 0xe0
> > +#define SY7802_REG_CONFIG_2 0xf0
> > +#define SY7802_REG_VIN_MONITOR 0x80
> > +#define SY7802_REG_LAST_FLASH 0x81
> > +#define SY7802_REG_VLED_MONITOR 0x30
> > +#define SY7802_REG_ADC_DELAY 0x31
> > +#define SY7802_REG_DEV_ID 0xff
> > +
> > +#define SY7802_MODE_OFF 0
> > +#define SY7802_MODE_TORCH 2
> > +#define SY7802_MODE_FLASH 3
> > +#define SY7802_MODE_MASK GENMASK(1, 0)
> > +
> > +#define SY7802_LEDS_SHIFT 3
> > +#define SY7802_LEDS_MASK(_id) (BIT(_id) << SY7802_LEDS_SHIFT)
> > +#define SY7802_LEDS_MASK_ALL (SY7802_LEDS_MASK(0) |
> > SY7802_LEDS_MASK(1))
> > +
> > +#define SY7802_TORCH_CURRENT_SHIFT 3
> > +#define SY7802_TORCH_CURRENT_MASK(_id) \
> > + (GENMASK(2, 0) << (SY7802_TORCH_CURRENT_SHIFT * (_id)))
> > +#define SY7802_TORCH_CURRENT_MASK_ALL \
> > + (SY7802_TORCH_CURRENT_MASK(0) |
> > SY7802_TORCH_CURRENT_MASK(1))
> > +
> > +#define SY7802_FLASH_CURRENT_SHIFT 4
> > +#define SY7802_FLASH_CURRENT_MASK(_id) \
> > + (GENMASK(3, 0) << (SY7802_FLASH_CURRENT_SHIFT * (_id)))
> > +#define SY7802_FLASH_CURRENT_MASK_ALL \
> > + (SY7802_FLASH_CURRENT_MASK(0) |
> > SY7802_FLASH_CURRENT_MASK(1))
> > +
> > +#define SY7802_TIMEOUT_DEFAULT_US 512000U
> > +#define SY7802_TIMEOUT_MIN_US 32000U
> > +#define SY7802_TIMEOUT_MAX_US 1024000U
> > +#define SY7802_TIMEOUT_STEPSIZE_US 32000U
> > +
> > +#define SY7802_TORCH_BRIGHTNESS_MAX 8
> > +
> > +#define SY7802_FLASH_BRIGHTNESS_DEFAULT 14
> > +#define SY7802_FLASH_BRIGHTNESS_MIN 0
> > +#define SY7802_FLASH_BRIGHTNESS_MAX 15
> > +#define SY7802_FLASH_BRIGHTNESS_STEP 1
> > +
> > +#define SY7802_FLAG_TIMEOUT BIT(0)
> > +#define SY7802_FLAG_THERMAL_SHUTDOWN BIT(1)
> > +#define SY7802_FLAG_LED_FAULT BIT(2)
> > +#define SY7802_FLAG_TX1_INTERRUPT BIT(3)
> > +#define SY7802_FLAG_TX2_INTERRUPT BIT(4)
> > +#define SY7802_FLAG_LED_THERMAL_FAULT BIT(5)
> > +#define SY7802_FLAG_FLASH_INPUT_VOLTAGE_LOW BIT(6)
> > +#define SY7802_FLAG_INPUT_VOLTAGE_LOW BIT(7)
> > +
> > +#define SY7802_CHIP_ID 0x51
> > +
> > +static const struct reg_default sy7802_regmap_defs[] = {
> > + { SY7802_REG_ENABLE, SY7802_LEDS_MASK_ALL },
> > + { SY7802_REG_TORCH_BRIGHTNESS, 0x92 },
> > + { SY7802_REG_FLASH_BRIGHTNESS,
> > SY7802_FLASH_BRIGHTNESS_DEFAULT |
> > + SY7802_FLASH_BRIGHTNESS_DEFAULT <<
> > SY7802_FLASH_CURRENT_SHIFT },
> > + { SY7802_REG_FLASH_DURATION, 0x6f },
> > + { SY7802_REG_FLAGS, 0x0 },
> > + { SY7802_REG_CONFIG_1, 0x68 },
> > + { SY7802_REG_CONFIG_2, 0xf0 },
>
> Not your fault, but this interface is frustrating since we have no
> idea
> what these register values mean. IMHO, they should be defined and
> ORed
> together in some human readable way.
>
> I say that it's not your fault because I see that this is the most
> common usage.
>
I don't know how to interpret some bits of the default values. I don't
have the documentation and changing the bits and observing the behavior
of the device also didn't help.
Should I remove the entries from sy7802_regmap_defs, which have values
that we don't fully understand?
Regards,
André
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