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

[Thomas Weißschuh]

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