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Date: Wed, 29 May 2024 02:56:09 +0300
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Bryan O'Donoghue <bryan.odonoghue@...aro.org>
Cc: Sebastian Reichel <sre@...nel.org>, Rob Herring <robh@...nel.org>,
Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley <conor+dt@...nel.org>,
Bjorn Andersson <andersson@...nel.org>, Hans de Goede <hdegoede@...hat.com>,
Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>, Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>, Konrad Dybcio <konrad.dybcio@...aro.org>,
linux-pm@...r.kernel.org, devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
platform-driver-x86@...r.kernel.org, linux-usb@...r.kernel.org, linux-arm-msm@...r.kernel.org,
Nikita Travkin <nikita@...n.ru>
Subject: Re: [PATCH v4 2/6] platform: arm64: add Lenovo Yoga C630 WOS EC
driver
On Wed, May 29, 2024 at 12:51:04AM +0100, Bryan O'Donoghue wrote:
> On 28/05/2024 21:44, Dmitry Baryshkov wrote:
> > Lenovo Yoga C630 WOS is a laptop using Snapdragon 850 SoC. Like many
> > laptops it uses embedded controller (EC) to perform various platform
>
> an embedded controller
>
> > operations, including, but not limited, to Type-C port control or power
> > supply handlng.
> >
> > Add the driver for the EC, that creates devices for UCSI and power
> > supply devices.
> >
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
> > ---
> > drivers/platform/arm64/Kconfig | 14 ++
> > drivers/platform/arm64/Makefile | 1 +
> > drivers/platform/arm64/lenovo-yoga-c630.c | 279 +++++++++++++++++++++++++
> > include/linux/platform_data/lenovo-yoga-c630.h | 42 ++++
> > 4 files changed, 336 insertions(+)
> >
> > diff --git a/drivers/platform/arm64/Kconfig b/drivers/platform/arm64/Kconfig
> > index 8fdca0f8e909..8c103b3150d1 100644
> > --- a/drivers/platform/arm64/Kconfig
> > +++ b/drivers/platform/arm64/Kconfig
> > @@ -32,4 +32,18 @@ config EC_ACER_ASPIRE1
> > laptop where this information is not properly exposed via the
> > standard ACPI devices.
> > +config EC_LENOVO_YOGA_C630
> > + tristate "Lenovo Yoga C630 Embedded Controller driver"
> > + depends on I2C
> > + help
> > + Driver for the Embedded Controller in the Qualcomm Snapdragon-based
> > + Lenovo Yoga C630, which provides battery and power adapter
> > + information.
> > +
> > + This driver provides battery and AC status support for the mentioned
> > + laptop where this information is not properly exposed via the
> > + standard ACPI devices.
> > +
> > + Say M or Y here to include this support.
> > +
> > endif # ARM64_PLATFORM_DEVICES
> > diff --git a/drivers/platform/arm64/Makefile b/drivers/platform/arm64/Makefile
> > index 4fcc9855579b..b2ae9114fdd8 100644
> > --- a/drivers/platform/arm64/Makefile
> > +++ b/drivers/platform/arm64/Makefile
> > @@ -6,3 +6,4 @@
> > #
> > obj-$(CONFIG_EC_ACER_ASPIRE1) += acer-aspire1-ec.o
> > +obj-$(CONFIG_EC_LENOVO_YOGA_C630) += lenovo-yoga-c630.o
> > diff --git a/drivers/platform/arm64/lenovo-yoga-c630.c b/drivers/platform/arm64/lenovo-yoga-c630.c
> > new file mode 100644
> > index 000000000000..3d1d5acde807
> > --- /dev/null
> > +++ b/drivers/platform/arm64/lenovo-yoga-c630.c
> > @@ -0,0 +1,279 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Copyright (c) 2022-2024, Linaro Ltd
> > + * Authors:
> > + * Bjorn Andersson
> > + * Dmitry Baryshkov
> > + */
> > +#include <linux/auxiliary_bus.h>
> > +#include <linux/i2c.h>
> > +#include <linux/module.h>
> > +#include <linux/notifier.h>
> > +#include <linux/platform_data/lenovo-yoga-c630.h>
> > +
> > +#define LENOVO_EC_RESPONSE_REG 0x01
> > +#define LENOVO_EC_REQUEST_REG 0x02
> > +
> > +#define LENOVO_EC_UCSI_WRITE 0x20
> > +#define LENOVO_EC_UCSI_READ 0x21
> > +
> > +#define LENOVO_EC_READ_REG 0xb0
> > +#define LENOVO_EC_REQUEST_NEXT_EVENT 0x84
> > +
> > +struct yoga_c630_ec {
> > + struct i2c_client *client;
> > + struct mutex lock;
> > + struct blocking_notifier_head notifier_list;
> > +};
> > +
> > +static int yoga_c630_ec_request(struct yoga_c630_ec *ec, u8 *req, size_t req_len,
> > + u8 *resp, size_t resp_len)
> > +{
> > + int ret;
> > +
> > + WARN_ON(!mutex_is_locked(&ec->lock));
> > +
> > + ret = i2c_smbus_write_i2c_block_data(ec->client, LENOVO_EC_REQUEST_REG,
> > + req_len, req);
> > + if (ret < 0)
> > + return ret;
> > +
> > + return i2c_smbus_read_i2c_block_data(ec->client, LENOVO_EC_RESPONSE_REG,
> > + resp_len, resp);
> > +}
> > +
> > +int yoga_c630_ec_read8(struct yoga_c630_ec *ec, u8 addr)
> > +{
> > + u8 req[2] = { LENOVO_EC_READ_REG, };
> > + int ret;
> > + u8 val;
> > +
> > + mutex_lock(&ec->lock);
> > + req[1] = addr;
> > + ret = yoga_c630_ec_request(ec, req, sizeof(req), &val, 1);
> > + mutex_unlock(&ec->lock);
> > +
> > + return ret < 0 ? ret : val;
> > +}
> > +EXPORT_SYMBOL_GPL(yoga_c630_ec_read8);
> > +
> > +int yoga_c630_ec_read16(struct yoga_c630_ec *ec, u8 addr)
> > +{
> > + u8 req[2] = { LENOVO_EC_READ_REG, };
> > + int ret;
> > + u8 msb;
> > + u8 lsb;
> > +
> > + mutex_lock(&ec->lock);
> > +
> > + req[1] = addr;
> > + ret = yoga_c630_ec_request(ec, req, sizeof(req), &lsb, 1);
> > + if (ret < 0)
> > + goto out;
> > +
> > + req[1] = addr + 1;
> > + ret = yoga_c630_ec_request(ec, req, sizeof(req), &msb, 1);
> > +
> > +out:
> > + mutex_unlock(&ec->lock);
> > +
> > + return ret < 0 ? ret : msb << 8 | lsb;
> > +}
> > +EXPORT_SYMBOL_GPL(yoga_c630_ec_read16);
> > +
> > +u16 yoga_c630_ec_ucsi_get_version(struct yoga_c630_ec *ec)
> > +{
> > + u8 req[3] = { 0xb3, 0xf2, 0x20};
>
> You have a define above for the read_reg and write_reg commands, could you
> not define 0xb3 as LENOVO_EC_GET_VERSION ?
>
> All of the other commands here seem to have a named define.
Because unlike other registers it is not clear what other use cases does
0xb3 support
>
> > + int ret;
> > + u8 msb;
> > + u8 lsb;
> > +
> > + mutex_lock(&ec->lock);
> > + ret = yoga_c630_ec_request(ec, req, sizeof(req), &lsb, 1);
> > + if (ret < 0)
> > + goto out;
> > +
> > + req[2]++;
>
> why not set reg[2] = 0x21;
ack
>
> also is req[2] some kind of address ?
Unfortunately no idea. This is totally based on the AML code in DSDT. I
have no documentation on the EC or its programming interface.
>
> > + ret = yoga_c630_ec_request(ec, req, sizeof(req), &msb, 1);
> > +
> > +out:
> > + mutex_unlock(&ec->lock);
> > +
> > + return ret < 0 ? ret : msb << 8 | lsb;
> > +}
> > +EXPORT_SYMBOL_GPL(yoga_c630_ec_ucsi_get_version);
> > +
> > +int yoga_c630_ec_ucsi_write(struct yoga_c630_ec *ec,
> > + const u8 req[YOGA_C630_UCSI_WRITE_SIZE])
> > +{
> > + int ret;
> > +
> > + mutex_lock(&ec->lock);
> > + ret = i2c_smbus_write_i2c_block_data(ec->client, LENOVO_EC_UCSI_WRITE,
> > + YOGA_C630_UCSI_WRITE_SIZE, req);
> > + mutex_unlock(&ec->lock);
> > +
> > + return ret < 0 ? ret : 0;
> > +}
> > +EXPORT_SYMBOL_GPL(yoga_c630_ec_ucsi_write);
> > +
> > +int yoga_c630_ec_ucsi_read(struct yoga_c630_ec *ec,
> > + u8 resp[YOGA_C630_UCSI_READ_SIZE])
> > +{
> > + int ret;
> > +
> > + mutex_lock(&ec->lock);
> > + ret = i2c_smbus_read_i2c_block_data(ec->client, LENOVO_EC_UCSI_READ,
> > + YOGA_C630_UCSI_READ_SIZE, resp);
> > + mutex_unlock(&ec->lock);
> > +
> > + return ret < 0 ? ret : 0;
> > +}
> > +EXPORT_SYMBOL_GPL(yoga_c630_ec_ucsi_read);
> > +
> > +static irqreturn_t yoga_c630_ec_intr(int irq, void *data)
> > +{
> > + u8 req[] = { LENOVO_EC_REQUEST_NEXT_EVENT };
> > + struct yoga_c630_ec *ec = data;
> > + u8 event;
> > + int ret;
> > +
> > + mutex_lock(&ec->lock);
> > + ret = yoga_c630_ec_request(ec, req, sizeof(req), &event, 1);
> > + mutex_unlock(&ec->lock);
> > + if (ret < 0)
> > + return IRQ_HANDLED;
> > +
> > + pr_info("NOTIFY %x\n", event);
>
> why not dev_info() ?
Argh, debugging code. I should drop it.
--
With best wishes
Dmitry
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