Re: [PATCH] platform/x86: Add Steam Deck driver

Hans de Goede
2022-02-17T16:41:54Z

Hi All,

On 2/17/22 17:26, Hans de Goede wrote:
> Hi Andrey,
>
> On 2/6/22 03:20, Andrey Smirnov wrote:
>> Add a driver exposing various bits and pieces of functionality
>> provided by Steam Deck specific VLV0100 device presented by EC
>> firmware. This includes but not limited to:
>>
>> - CPU/device's fan control
>> - Read-only access to DDIC registers
>> - Battery tempreature measurements
>> - Various display related control knobs
>> - USB Type-C connector event notification
>>
>> Cc: Hans de Goede <hdegoede@redhat.com>
>> Cc: Mark Gross <markgross@kernel.org>
>> Cc: Jean Delvare <jdelvare@suse.com>
>> Cc: Guenter Roeck <linux@roeck-us.net>
>> Cc: linux-kernel@vger.kernel.org (open list)
>> Cc: platform-driver-x86@vger.kernel.org
>> Cc: linux-hwmon@vger.kernel.org
>> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
>
> The .c file says: "Copyright (C) 2021-2022 Valve Corporation"
> yet you are using a personal email address. This is not really
> an issue, but it does look a bit weird.
>
>> ---
>>
>> This driver is really a kitchen sink of various small bits. Maybe it
>> is worth splitting into an MFD + child drivers/devices?
>
> Yes with the extcon thing I think you should definitely go for
> a MFD device. In which case the main driver registering the
> regmap + the cells would go under drivers/mfd and most of the
> other drivers would go in their own subsystems.
>
> And as the drivers/platform/x86/ subsystem maintainer I guess
> that means I don't have to do much with this driver :)
>
> I would still be happy to take any bits which don't fit
> anywhere else attaching to say a "misc" MFD cell.
>
> Regards,
>
> Hans

Sorry for sending an almost identical mail twice, at first
I thought my email-client (thunderbird) somehow ate this one,
as it did not show in my send folder.

But now I see that I somehow accidentally changed from which
account I send the reply.

Regards,

Hans

>
>
>
>>
>> drivers/platform/x86/Kconfig | 15 +
>> drivers/platform/x86/Makefile | 2 +
>> drivers/platform/x86/steamdeck.c | 523 +++++++++++++++++++++++++++++++
>> 3 files changed, 540 insertions(+)
>> create mode 100644 drivers/platform/x86/steamdeck.c
>>
>> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
>> index c23612d98126..86f014e78a6e 100644
>> --- a/drivers/platform/x86/Kconfig
>> +++ b/drivers/platform/x86/Kconfig
>> @@ -1136,6 +1136,21 @@ config SIEMENS_SIMATIC_IPC
>> To compile this driver as a module, choose M here: the module
>> will be called simatic-ipc.
>>
>> +config STEAMDECK
>> + tristate "Valve Steam Deck platform driver"
>> + depends on X86_64
>> + help
>> + Driver exposing various bits and pieces of functionality
>> + provided by Steam Deck specific VLV0100 device presented by
>> + EC firmware. This includes but not limited to:
>> + - CPU/device's fan control
>> + - Read-only access to DDIC registers
>> + - Battery tempreature measurements
>> + - Various display related control knobs
>> + - USB Type-C connector event notification
>> +
>> + Say N unless you are running on a Steam Deck.
>> +
>> endif # X86_PLATFORM_DEVICES
>>
>> config PMC_ATOM
>> diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
>> index c12a9b044fd8..2eb965e14ced 100644
>> --- a/drivers/platform/x86/Makefile
>> +++ b/drivers/platform/x86/Makefile
>> @@ -129,3 +129,5 @@ obj-$(CONFIG_PMC_ATOM) += pmc_atom.o
>>
>> # Siemens Simatic Industrial PCs
>> obj-$(CONFIG_SIEMENS_SIMATIC_IPC) += simatic-ipc.o
>> +
>> +obj-$(CONFIG_STEAMDECK) += steamdeck.o
>> diff --git a/drivers/platform/x86/steamdeck.c b/drivers/platform/x86/steamdeck.c
>> new file mode 100644
>> index 000000000000..77a6677ec19e
>> --- /dev/null
>> +++ b/drivers/platform/x86/steamdeck.c
>> @@ -0,0 +1,523 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +
>> +/*
>> + * Steam Deck ACPI platform driver
>> + *
>> + * Copyright (C) 2021-2022 Valve Corporation
>> + *
>> + */
>> +#include <linux/acpi.h>
>> +#include <linux/hwmon.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/regmap.h>
>> +#include <linux/extcon-provider.h>
>> +
>> +#define ACPI_STEAMDECK_NOTIFY_STATUS 0x80
>> +
>> +/* 0 - port connected, 1 -port disconnected */
>> +#define ACPI_STEAMDECK_PORT_CONNECT BIT(0)
>> +/* 0 - Upstream Facing Port, 1 - Downdstream Facing Port */
>> +#define ACPI_STEAMDECK_CUR_DATA_ROLE BIT(3)
>> +/*
>> + * Debouncing delay to allow negotiation process to settle. 2s value
>> + * was arrived at via trial and error.
>> + */
>> +#define STEAMDECK_ROLE_SWITCH_DELAY (msecs_to_jiffies(2000))
>> +
>> +struct steamdeck {
>> + struct acpi_device *adev;
>> + struct device *hwmon;
>> + void *regmap;
>> + long fan_target;
>> + struct delayed_work role_work;
>> + struct extcon_dev *edev;
>> + struct device *dev;
>> +};
>> +
>> +static ssize_t
>> +steamdeck_simple_store(struct device *dev, const char *buf, size_t count,
>> + const char *method,
>> + unsigned long upper_limit)
>> +{
>> + struct steamdeck *fan = dev_get_drvdata(dev);
>> + unsigned long value;
>> +
>> + if (kstrtoul(buf, 10, &value) || value >= upper_limit)
>> + return -EINVAL;
>> +
>> + if (ACPI_FAILURE(acpi_execute_simple_method(fan->adev->handle,
>> + (char *)method, value)))
>> + return -EIO;
>> +
>> + return count;
>> +}
>> +
>> +#define STEAMDECK_ATTR_WO(_name, _method, _upper_limit) \
>> + static ssize_t _name##_store(struct device *dev, \
>> + struct device_attribute *attr, \
>> + const char *buf, size_t count) \
>> + { \
>> + return steamdeck_simple_store(dev, buf, count, \
>> + _method, \
>> + _upper_limit); \
>> + } \
>> + static DEVICE_ATTR_WO(_name)
>> +
>> +STEAMDECK_ATTR_WO(target_cpu_temp, "STCT", U8_MAX / 2);
>> +STEAMDECK_ATTR_WO(gain, "SGAN", U16_MAX);
>> +STEAMDECK_ATTR_WO(ramp_rate, "SFRR", U8_MAX);
>> +STEAMDECK_ATTR_WO(hysteresis, "SHTS", U16_MAX);
>> +STEAMDECK_ATTR_WO(maximum_battery_charge_rate, "CHGR", U16_MAX);
>> +STEAMDECK_ATTR_WO(recalculate, "SCHG", U16_MAX);
>> +
>> +STEAMDECK_ATTR_WO(led_brightness, "CHBV", U8_MAX);
>> +STEAMDECK_ATTR_WO(content_adaptive_brightness, "CABC", U8_MAX);
>> +STEAMDECK_ATTR_WO(gamma_set, "GAMA", U8_MAX);
>> +STEAMDECK_ATTR_WO(display_brightness, "WDBV", U8_MAX);
>> +STEAMDECK_ATTR_WO(ctrl_display, "WCDV", U8_MAX);
>> +STEAMDECK_ATTR_WO(cabc_minimum_brightness, "WCMB", U8_MAX);
>> +STEAMDECK_ATTR_WO(memory_data_access_control, "MDAC", U8_MAX);
>> +
>> +#define STEAMDECK_ATTR_WO_NOARG(_name, _method) \
>> + static ssize_t _name##_store(struct device *dev, \
>> + struct device_attribute *attr, \
>> + const char *buf, size_t count) \
>> + { \
>> + struct steamdeck *fan = dev_get_drvdata(dev); \
>> + \
>> + if (ACPI_FAILURE(acpi_evaluate_object(fan->adev->handle, \
>> + _method, NULL, NULL))) \
>> + return -EIO; \
>> + \
>> + return count; \
>> + } \
>> + static DEVICE_ATTR_WO(_name)
>> +
>> +STEAMDECK_ATTR_WO_NOARG(power_cycle_display, "DPCY");
>> +STEAMDECK_ATTR_WO_NOARG(display_normal_mode_on, "NORO");
>> +STEAMDECK_ATTR_WO_NOARG(display_inversion_off, "INOF");
>> +STEAMDECK_ATTR_WO_NOARG(display_inversion_on, "INON");
>> +STEAMDECK_ATTR_WO_NOARG(idle_mode_on, "WRNE");
>> +
>> +#define STEAMDECK_ATTR_RO(_name, _method) \
>> + static ssize_t _name##_show(struct device *dev, \
>> + struct device_attribute *attr, \
>> + char *buf) \
>> + { \
>> + struct steamdeck *jup = dev_get_drvdata(dev); \
>> + unsigned long long val; \
>> + \
>> + if (ACPI_FAILURE(acpi_evaluate_integer( \
>> + jup->adev->handle, \
>> + _method, NULL, &val))) \
>> + return -EIO; \
>> + \
>> + return sprintf(buf, "%llu\n", val); \
>> + } \
>> + static DEVICE_ATTR_RO(_name)
>> +
>> +STEAMDECK_ATTR_RO(firmware_version, "PDFW");
>> +STEAMDECK_ATTR_RO(board_id, "BOID");
>> +STEAMDECK_ATTR_RO(pdcs, "PDCS");
>> +
>> +static umode_t
>> +steamdeck_is_visible(struct kobject *kobj, struct attribute *attr, int index)
>> +{
>> + return attr->mode;
>> +}
>> +
>> +static struct attribute *steamdeck_attributes[] = {
>> + &dev_attr_target_cpu_temp.attr,
>> + &dev_attr_gain.attr,
>> + &dev_attr_ramp_rate.attr,
>> + &dev_attr_hysteresis.attr,
>> + &dev_attr_maximum_battery_charge_rate.attr,
>> + &dev_attr_recalculate.attr,
>> + &dev_attr_power_cycle_display.attr,
>> +
>> + &dev_attr_led_brightness.attr,
>> + &dev_attr_content_adaptive_brightness.attr,
>> + &dev_attr_gamma_set.attr,
>> + &dev_attr_display_brightness.attr,
>> + &dev_attr_ctrl_display.attr,
>> + &dev_attr_cabc_minimum_brightness.attr,
>> + &dev_attr_memory_data_access_control.attr,
>> +
>> + &dev_attr_display_normal_mode_on.attr,
>> + &dev_attr_display_inversion_off.attr,
>> + &dev_attr_display_inversion_on.attr,
>> + &dev_attr_idle_mode_on.attr,
>> +
>> + &dev_attr_firmware_version.attr,
>> + &dev_attr_board_id.attr,
>> + &dev_attr_pdcs.attr,
>> +
>> + NULL
>> +};
>> +
>> +static const struct attribute_group steamdeck_group = {
>> + .attrs = steamdeck_attributes,
>> + .is_visible = steamdeck_is_visible,
>> +};
>> +
>> +static const struct attribute_group *steamdeck_groups[] = {
>> + &steamdeck_group,
>> + NULL
>> +};
>> +
>> +static int steamdeck_read_fan_speed(struct steamdeck *jup, long *speed)
>> +{
>> + unsigned long long val;
>> +
>> + if (ACPI_FAILURE(acpi_evaluate_integer(jup->adev->handle,
>> + "FANR", NULL, &val)))
>> + return -EIO;
>> +
>> + *speed = val;
>> + return 0;
>> +}
>> +
>> +static int
>> +steamdeck_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
>> + u32 attr, int channel, long *out)
>> +{
>> + struct steamdeck *sd = dev_get_drvdata(dev);
>> + unsigned long long val;
>> +
>> + switch (type) {
>> + case hwmon_temp:
>> + if (attr != hwmon_temp_input)
>> + return -EOPNOTSUPP;
>> +
>> + if (ACPI_FAILURE(acpi_evaluate_integer(sd->adev->handle,
>> + "BATT", NULL, &val)))
>> + return -EIO;
>> + /*
>> + * Assuming BATT returns deg C we need to mutiply it
>> + * by 1000 to convert to mC
>> + */
>> + *out = val * 1000;
>> + break;
>> + case hwmon_fan:
>> + switch (attr) {
>> + case hwmon_fan_input:
>> + return steamdeck_read_fan_speed(sd, out);
>> + case hwmon_fan_target:
>> + *out = sd->fan_target;
>> + break;
>> + case hwmon_fan_fault:
>> + if (ACPI_FAILURE(acpi_evaluate_integer(
>> + sd->adev->handle,
>> + "FANC", NULL, &val)))
>> + return -EIO;
>> + /*
>> + * FANC (Fan check):
>> + * 0: Abnormal
>> + * 1: Normal
>> + */
>> + *out = !val;
>> + break;
>> + default:
>> + return -EOPNOTSUPP;
>> + }
>> + break;
>> + default:
>> + return -EOPNOTSUPP;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int
>> +steamdeck_hwmon_read_string(struct device *dev, enum hwmon_sensor_types type,
>> + u32 attr, int channel, const char **str)
>> +{
>> + switch (type) {
>> + case hwmon_temp:
>> + *str = "Battery Temp";
>> + break;
>> + case hwmon_fan:
>> + *str = "System Fan";
>> + break;
>> + default:
>> + return -EOPNOTSUPP;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int
>> +steamdeck_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
>> + u32 attr, int channel, long val)
>> +{
>> + struct steamdeck *sd = dev_get_drvdata(dev);
>> +
>> + if (type != hwmon_fan ||
>> + attr != hwmon_fan_target)
>> + return -EOPNOTSUPP;
>> +
>> + if (val > U16_MAX)
>> + return -EINVAL;
>> +
>> + sd->fan_target = val;
>> +
>> + if (ACPI_FAILURE(acpi_execute_simple_method(sd->adev->handle,
>> + "FANS", val)))
>> + return -EIO;
>> +
>> + return 0;
>> +}
>> +
>> +static umode_t
>> +steamdeck_hwmon_is_visible(const void *data, enum hwmon_sensor_types type,
>> + u32 attr, int channel)
>> +{
>> + if (type == hwmon_fan &&
>> + attr == hwmon_fan_target)
>> + return 0644;
>> +
>> + return 0444;
>> +}
>> +
>> +static const struct hwmon_channel_info *steamdeck_info[] = {
>> + HWMON_CHANNEL_INFO(temp,
>> + HWMON_T_INPUT | HWMON_T_LABEL),
>> + HWMON_CHANNEL_INFO(fan,
>> + HWMON_F_INPUT | HWMON_F_LABEL |
>> + HWMON_F_TARGET | HWMON_F_FAULT),
>> + NULL
>> +};
>> +
>> +static const struct hwmon_ops steamdeck_hwmon_ops = {
>> + .is_visible = steamdeck_hwmon_is_visible,
>> + .read = steamdeck_hwmon_read,
>> + .read_string = steamdeck_hwmon_read_string,
>> + .write = steamdeck_hwmon_write,
>> +};
>> +
>> +static const struct hwmon_chip_info steamdeck_chip_info = {
>> + .ops = &steamdeck_hwmon_ops,
>> + .info = steamdeck_info,
>> +};
>> +
>> +#define STEAMDECK_STA_OK \
>> + (ACPI_STA_DEVICE_ENABLED | \
>> + ACPI_STA_DEVICE_PRESENT | \
>> + ACPI_STA_DEVICE_FUNCTIONING)
>> +
>> +static int
>> +steamdeck_ddic_reg_read(void *context, unsigned int reg, unsigned int *val)
>> +{
>> + union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
>> + struct acpi_object_list arg_list = { .count = 1, .pointer = &obj, };
>> + struct steamdeck *sd = context;
>> + unsigned long long _val;
>> +
>> + obj.integer.value = reg;
>> +
>> + if (ACPI_FAILURE(acpi_evaluate_integer(sd->adev->handle,
>> + "RDDI", &arg_list, &_val)))
>> + return -EIO;
>> +
>> + *val = _val;
>> + return 0;
>> +}
>> +
>> +static int steamdeck_read_pdcs(struct steamdeck *sd, unsigned long long *pdcs)
>> +{
>> + acpi_status status;
>> +
>> + status = acpi_evaluate_integer(sd->adev->handle, "PDCS", NULL, pdcs);
>> + if (ACPI_FAILURE(status)) {
>> + dev_err(sd->dev, "PDCS evaluation failed: %s\n",
>> + acpi_format_exception(status));
>> + return -EIO;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static void steamdeck_usb_role_work(struct work_struct *work)
>> +{
>> + struct steamdeck *sd =
>> + container_of(work, struct steamdeck, role_work.work);
>> + unsigned long long pdcs;
>> + bool usb_host;
>> +
>> + if (steamdeck_read_pdcs(sd, &pdcs))
>> + return;
>> +
>> + /*
>> + * We only care about these two
>> + */
>> + pdcs &= ACPI_STEAMDECK_PORT_CONNECT | ACPI_STEAMDECK_CUR_DATA_ROLE;
>> +
>> + /*
>> + * For "connect" events our role is determined by a bit in
>> + * PDCS, for "disconnect" we switch to being a gadget
>> + * unconditionally. The thinking for the latter is we don't
>> + * want to start acting as a USB host until we get
>> + * confirmation from the firmware that we are a USB host
>> + */
>> + usb_host = (pdcs & ACPI_STEAMDECK_PORT_CONNECT) ?
>> + pdcs & ACPI_STEAMDECK_CUR_DATA_ROLE : false;
>> +
>> + WARN_ON(extcon_set_state_sync(sd->edev, EXTCON_USB_HOST,
>> + usb_host));
>> + dev_dbg(sd->dev, "USB role is %s\n", usb_host ? "host" : "device");
>> +}
>> +
>> +static void steamdeck_notify(acpi_handle handle, u32 event, void *context)
>> +{
>> + struct device *dev = context;
>> + struct steamdeck *sd = dev_get_drvdata(dev);
>> + unsigned long long pdcs;
>> + unsigned long delay;
>> +
>> + switch (event) {
>> + case ACPI_STEAMDECK_NOTIFY_STATUS:
>> + if (steamdeck_read_pdcs(sd, &pdcs))
>> + return;
>> + /*
>> + * We process "disconnect" events immediately and
>> + * "connect" events with a delay to give the HW time
>> + * to settle. For example attaching USB hub (at least
>> + * for HW used for testing) will generate intermediary
>> + * event with "host" bit not set, followed by the one
>> + * that does have it set.
>> + */
>> + delay = (pdcs & ACPI_STEAMDECK_PORT_CONNECT) ?
>> + STEAMDECK_ROLE_SWITCH_DELAY : 0;
>> +
>> + queue_delayed_work(system_long_wq, &sd->role_work, delay);
>> + break;
>> + default:
>> + dev_err(dev, "Unsupported event [0x%x]\n", event);
>> + }
>> +}
>> +
>> +static void steamdeck_remove_notify_handler(void *data)
>> +{
>> + struct steamdeck *sd = data;
>> +
>> + acpi_remove_notify_handler(sd->adev->handle, ACPI_DEVICE_NOTIFY,
>> + steamdeck_notify);
>> + cancel_delayed_work_sync(&sd->role_work);
>> +}
>> +
>> +static const unsigned int steamdeck_extcon_cable[] = {
>> + EXTCON_USB,
>> + EXTCON_USB_HOST,
>> + EXTCON_CHG_USB_SDP,
>> + EXTCON_CHG_USB_CDP,
>> + EXTCON_CHG_USB_DCP,
>> + EXTCON_CHG_USB_ACA,
>> + EXTCON_NONE,
>> +};
>> +
>> +static int steamdeck_probe(struct platform_device *pdev)
>> +{
>> + struct device *dev = &pdev->dev;
>> + struct steamdeck *sd;
>> + acpi_status status;
>> + unsigned long long sta;
>> + int ret;
>> +
>> + static const struct regmap_config regmap_config = {
>> + .reg_bits = 8,
>> + .val_bits = 8,
>> + .max_register = 255,
>> + .cache_type = REGCACHE_NONE,
>> + .reg_read = steamdeck_ddic_reg_read,
>> + };
>> +
>> + sd = devm_kzalloc(dev, sizeof(*sd), GFP_KERNEL);
>> + if (!sd)
>> + return -ENOMEM;
>> + sd->adev = ACPI_COMPANION(&pdev->dev);
>> + sd->dev = dev;
>> + platform_set_drvdata(pdev, sd);
>> + INIT_DELAYED_WORK(&sd->role_work, steamdeck_usb_role_work);
>> +
>> + status = acpi_evaluate_integer(sd->adev->handle, "_STA",
>> + NULL, &sta);
>> + if (ACPI_FAILURE(status)) {
>> + dev_err(dev, "Status check failed (0x%x)\n", status);
>> + return -EINVAL;
>> + }
>> +
>> + if ((sta & STEAMDECK_STA_OK) != STEAMDECK_STA_OK) {
>> + dev_err(dev, "Device is not ready\n");
>> + return -EINVAL;
>> + }
>> +
>> + /*
>> + * Our ACPI interface doesn't expose a method to read current
>> + * fan target, so we use current fan speed as an
>> + * approximation.
>> + */
>> + if (steamdeck_read_fan_speed(sd, &sd->fan_target))
>> + dev_warn(dev, "Failed to read fan speed");
>> +
>> + sd->hwmon = devm_hwmon_device_register_with_info(dev,
>> + "steamdeck",
>> + sd,
>> + &steamdeck_chip_info,
>> + steamdeck_groups);
>> + if (IS_ERR(sd->hwmon)) {
>> + dev_err(dev, "Failed to register HWMON device");
>> + return PTR_ERR(sd->hwmon);
>> + }
>> +
>> + sd->regmap = devm_regmap_init(dev, NULL, sd, &regmap_config);
>> + if (IS_ERR(sd->regmap))
>> + dev_err(dev, "Failed to register REGMAP");
>> +
>> + sd->edev = devm_extcon_dev_allocate(dev, steamdeck_extcon_cable);
>> + if (IS_ERR(sd->edev))
>> + return -ENOMEM;
>> +
>> + ret = devm_extcon_dev_register(dev, sd->edev);
>> + if (ret < 0) {
>> + dev_err(dev, "Failed to register extcon device: %d\n", ret);
>> + return ret;
>> + }
>> +
>> + /*
>> + * Set initial role value
>> + */
>> + queue_delayed_work(system_long_wq, &sd->role_work, 0);
>> + flush_delayed_work(&sd->role_work);
>> +
>> + status = acpi_install_notify_handler(sd->adev->handle,
>> + ACPI_DEVICE_NOTIFY,
>> + steamdeck_notify,
>> + dev);
>> + if (ACPI_FAILURE(status)) {
>> + dev_err(dev, "Error installing ACPI notify handler\n");
>> + return -EIO;
>> + }
>> +
>> + ret = devm_add_action_or_reset(dev, steamdeck_remove_notify_handler,
>> + sd);
>> + return ret;
>> +}
>> +
>> +static const struct acpi_device_id steamdeck_device_ids[] = {
>> + { "VLV0100", 0 },
>> + { "", 0 },
>> +};
>> +MODULE_DEVICE_TABLE(acpi, steamdeck_device_ids);
>> +
>> +static struct platform_driver steamdeck_driver = {
>> + .probe = steamdeck_probe,
>> + .driver = {
>> + .name = "steamdeck",
>> + .acpi_match_table = steamdeck_device_ids,
>> + },
>> +};
>> +module_platform_driver(steamdeck_driver);
>> +
>> +MODULE_AUTHOR("Andrey Smirnov <andrew.smirnov@gmail.com>");
>> +MODULE_DESCRIPTION("Steam Deck ACPI platform driver");
>> +MODULE_LICENSE("GPL");
>> --
>> 2.25.1
>>
>