[PATCH 1/2] platform/chrome: cros_ec_framework_laptop: introduce driver

From: Thomas Weißschuh
Date: Sun May 05 2024 - 16:57:30 EST


Framework Laptops are using embedded controller firmware based on the
ChromeOS EC project.
In addition to the standard upstream commands, some vendor-specific
ones are implemented.

Add a driver for those custom EC commands.

At first, provide an empty driver that only takes care of scaffolding and
device binding.
Further patches will add functionality to the driver.

Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
---
MAINTAINERS | 5 ++
drivers/mfd/cros_ec_dev.c | 13 ++++++
drivers/platform/chrome/Kconfig | 11 +++++
drivers/platform/chrome/Makefile | 1 +
drivers/platform/chrome/cros_ec_framework_laptop.c | 53 ++++++++++++++++++++++
5 files changed, 83 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index c23fda1aa1f0..60699c289757 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4988,6 +4988,11 @@ S: Maintained
F: Documentation/devicetree/bindings/sound/google,cros-ec-codec.yaml
F: sound/soc/codecs/cros_ec_codec.*

+CHROMEOS EC FRAMEWORK LAPTOP EXTENSIONS
+M: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
+S: Maintained
+F: drivers/platform/chrome/cros_ec_framework_laptop.c
+
CHROMEOS EC SUBDRIVERS
M: Benson Leung <bleung@xxxxxxxxxxxx>
R: Guenter Roeck <groeck@xxxxxxxxxxxx>
diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
index a52d59cc2b1e..0a36e77e5039 100644
--- a/drivers/mfd/cros_ec_dev.c
+++ b/drivers/mfd/cros_ec_dev.c
@@ -145,6 +145,10 @@ static const struct mfd_cell cros_ec_vbc_cells[] = {
{ .name = "cros-ec-vbc", }
};

+static const struct mfd_cell cros_ec_framework_cells[] = {
+ { .name = "cros-ec-framework", }
+};
+
static void cros_ec_class_release(struct device *dev)
{
kfree(to_cros_ec_dev(dev));
@@ -299,6 +303,15 @@ static int ec_device_probe(struct platform_device *pdev)
retval);
}

+ /* The EC on Framework laptops implements some nonstandard features */
+ if (dmi_match(DMI_SYS_VENDOR, "Framework")) {
+ retval = mfd_add_hotplug_devices(ec->dev, cros_ec_framework_cells,
+ ARRAY_SIZE(cros_ec_framework_cells));
+ if (retval)
+ dev_warn(ec->dev, "failed to add framework laptop devices: %d\n",
+ retval);
+ }
+
return 0;

failed:
diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig
index 073616b5b5a0..ff69ee226606 100644
--- a/drivers/platform/chrome/Kconfig
+++ b/drivers/platform/chrome/Kconfig
@@ -239,6 +239,17 @@ config CROS_EC_TYPEC
To compile this driver as a module, choose M here: the module will be
called cros-ec-typec.

+config CROS_EC_FRAMEWORK_LAPTOP
+ tristate "ChromeOS EC Framework Laptop extensions"
+ depends on MFD_CROS_EC_DEV
+ default MFD_CROS_EC_DEV
+ help
+ If you say Y here, you get support for using Framework Laptop-specific extensions
+ of the Chrome OS EC.
+
+ To compile this driver as a module, choose M here: the module will be
+ called cros_ec_framework_laptop.
+
config CROS_HPS_I2C
tristate "ChromeOS HPS device"
depends on HID && I2C && PM
diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
index 2dcc6ccc2302..ce6aac620086 100644
--- a/drivers/platform/chrome/Makefile
+++ b/drivers/platform/chrome/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_CHROMEOS_PRIVACY_SCREEN) += chromeos_privacy_screen.o
obj-$(CONFIG_CHROMEOS_PSTORE) += chromeos_pstore.o
obj-$(CONFIG_CHROMEOS_TBMC) += chromeos_tbmc.o
obj-$(CONFIG_CROS_EC) += cros_ec.o
+obj-$(CONFIG_CROS_EC_FRAMEWORK_LAPTOP) += cros_ec_framework_laptop.o
obj-$(CONFIG_CROS_EC_I2C) += cros_ec_i2c.o
obj-$(CONFIG_CROS_EC_ISHTP) += cros_ec_ishtp.o
obj-$(CONFIG_CROS_TYPEC_SWITCH) += cros_typec_switch.o
diff --git a/drivers/platform/chrome/cros_ec_framework_laptop.c b/drivers/platform/chrome/cros_ec_framework_laptop.c
new file mode 100644
index 000000000000..8a8bf039fa9c
--- /dev/null
+++ b/drivers/platform/chrome/cros_ec_framework_laptop.c
@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * ChromesOS EC driver for Framework laptop
+ *
+ * Copyright (C) 2024 Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
+ */
+#include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_data/cros_ec_proto.h>
+#include <linux/platform_device.h>
+
+#define DRV_NAME "cros-ec-framework"
+
+struct cros_fwk_priv {
+ struct cros_ec_device *cros_ec;
+};
+
+static int cros_fwk_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
+ struct cros_ec_device *cros_ec = ec_dev->ec_dev;
+ struct cros_fwk_priv *priv;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->cros_ec = cros_ec;
+
+ platform_set_drvdata(pdev, priv);
+
+ return 0;
+}
+
+static const struct platform_device_id cros_fwk_id[] = {
+ { DRV_NAME, 0 },
+ { }
+};
+
+static struct platform_driver cros_fwk_driver = {
+ .driver.name = DRV_NAME,
+ .probe = cros_fwk_probe,
+ .id_table = cros_fwk_id,
+};
+
+module_platform_driver(cros_fwk_driver);
+
+MODULE_DEVICE_TABLE(platform, cros_fwk_id);
+MODULE_DESCRIPTION("ChromeOS EC Framework Laptop extensions");
+MODULE_AUTHOR("Thomas Weißschuh <linux@xxxxxxxxxxxxxx");
+MODULE_LICENSE("GPL");

--
2.45.0