usb: typec: ucsi: Add ACPI driver

Driver for ACPI UCSI interface method. This driver replaces
the previous UCSI driver drivers/usb/misc/ucsi.c.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 176 insertions, 0 deletions

diff --git a/drivers/usb/typec/ucsi/Kconfig b/drivers/usb/typec/ucsi/Kconfig
index da4c5c3d8870..d0c31cee4720 100644
--- a/drivers/usb/typec/ucsi/Kconfig
+++ b/drivers/usb/typec/ucsi/Kconfig
@@ -21,3 +21,19 @@ config TYPEC_UCSI
 
 	  To compile the driver as a module, choose M here: the module will be
 	  called typec_ucsi.
+
+if TYPEC_UCSI
+
+config UCSI_ACPI
+	tristate "UCSI ACPI Interface Driver"
+	depends on ACPI
+	help
+	  This driver enables UCSI support on platforms that expose UCSI
+	  interface as ACPI device. On new Intel Atom based platforms starting
+	  from Broxton SoCs and Core platforms stating from Skylake, UCSI is an
+	  ACPI enumerated device.
+
+	  To compile the driver as a module, choose M here: the module will be
+	  called ucsi_acpi
+
+endif
diff --git a/drivers/usb/typec/ucsi/Makefile b/drivers/usb/typec/ucsi/Makefile
index 87dd6ee6c9f3..8372fc22f9b3 100644
--- a/drivers/usb/typec/ucsi/Makefile
+++ b/drivers/usb/typec/ucsi/Makefile
@@ -5,3 +5,5 @@ obj-$(CONFIG_TYPEC_UCSI)	+= typec_ucsi.o
 typec_ucsi-y			:= ucsi.o
 
 typec_ucsi-$(CONFIG_FTRACE)	+= trace.o
+
+obj-$(CONFIG_UCSI_ACPI)		+= ucsi_acpi.o
diff --git a/drivers/usb/typec/ucsi/ucsi_acpi.c b/drivers/usb/typec/ucsi/ucsi_acpi.c
new file mode 100644
index 000000000000..3fb2e48e1c91
--- /dev/null
+++ b/drivers/usb/typec/ucsi/ucsi_acpi.c
@@ -0,0 +1,158 @@
+/*
+ * UCSI ACPI driver
+ *
+ * Copyright (C) 2017, Intel Corporation
+ * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/acpi.h>
+
+#include "ucsi.h"
+
+#define UCSI_DSM_UUID		"6f8398c2-7ca4-11e4-ad36-631042b5008f"
+#define UCSI_DSM_FUNC_WRITE	1
+#define UCSI_DSM_FUNC_READ	2
+
+struct ucsi_acpi {
+	struct device *dev;
+	struct ucsi *ucsi;
+	struct ucsi_ppm ppm;
+	uuid_le uuid;
+};
+
+static int ucsi_acpi_dsm(struct ucsi_acpi *ua, int func)
+{
+	union acpi_object *obj;
+
+	obj = acpi_evaluate_dsm(ACPI_HANDLE(ua->dev), ua->uuid.b, 1, func,
+				NULL);
+	if (!obj) {
+		dev_err(ua->dev, "%s: failed to evaluate _DSM %d\n",
+			__func__, func);
+		return -EIO;
+	}
+
+	ACPI_FREE(obj);
+	return 0;
+}
+
+static int ucsi_acpi_cmd(struct ucsi_ppm *ppm, struct ucsi_control *ctrl)
+{
+	struct ucsi_acpi *ua = container_of(ppm, struct ucsi_acpi, ppm);
+
+	ppm->data->ctrl.raw_cmd = ctrl->raw_cmd;
+
+	return ucsi_acpi_dsm(ua, UCSI_DSM_FUNC_WRITE);
+}
+
+static int ucsi_acpi_sync(struct ucsi_ppm *ppm)
+{
+	struct ucsi_acpi *ua = container_of(ppm, struct ucsi_acpi, ppm);
+
+	return ucsi_acpi_dsm(ua, UCSI_DSM_FUNC_READ);
+}
+
+static void ucsi_acpi_notify(acpi_handle handle, u32 event, void *data)
+{
+	struct ucsi_acpi *ua = data;
+
+	ucsi_notify(ua->ucsi);
+}
+
+static int ucsi_acpi_probe(struct platform_device *pdev)
+{
+	struct ucsi_acpi *ua;
+	struct resource *res;
+	acpi_status status;
+	int ret;
+
+	ua = devm_kzalloc(&pdev->dev, sizeof(*ua), GFP_KERNEL);
+	if (!ua)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "missing memory resource\n");
+		return -ENODEV;
+	}
+
+	/*
+	 * NOTE: The memory region for the data structures is used also in an
+	 * operation region, which means ACPI has already reserved it. Therefore
+	 * it can not be requested here, and we can not use
+	 * devm_ioremap_resource().
+	 */
+	ua->ppm.data = devm_ioremap(&pdev->dev, res->start, resource_size(res));
+	if (!ua->ppm.data)
+		return -ENOMEM;
+
+	if (!ua->ppm.data->version)
+		return -ENODEV;
+
+	ret = uuid_le_to_bin(UCSI_DSM_UUID, &ua->uuid);
+	if (ret)
+		return ret;
+
+	ua->ppm.cmd = ucsi_acpi_cmd;
+	ua->ppm.sync = ucsi_acpi_sync;
+	ua->dev = &pdev->dev;
+
+	status = acpi_install_notify_handler(ACPI_HANDLE(&pdev->dev),
+					     ACPI_DEVICE_NOTIFY,
+					     ucsi_acpi_notify, ua);
+	if (ACPI_FAILURE(status)) {
+		dev_err(&pdev->dev, "failed to install notify handler\n");
+		return -ENODEV;
+	}
+
+	ua->ucsi = ucsi_register_ppm(&pdev->dev, &ua->ppm);
+	if (IS_ERR(ua->ucsi)) {
+		acpi_remove_notify_handler(ACPI_HANDLE(&pdev->dev),
+					   ACPI_DEVICE_NOTIFY,
+					   ucsi_acpi_notify);
+		return PTR_ERR(ua->ucsi);
+	}
+
+	platform_set_drvdata(pdev, ua);
+
+	return 0;
+}
+
+static int ucsi_acpi_remove(struct platform_device *pdev)
+{
+	struct ucsi_acpi *ua = platform_get_drvdata(pdev);
+
+	ucsi_unregister_ppm(ua->ucsi);
+
+	acpi_remove_notify_handler(ACPI_HANDLE(&pdev->dev), ACPI_DEVICE_NOTIFY,
+				   ucsi_acpi_notify);
+
+	return 0;
+}
+
+static const struct acpi_device_id ucsi_acpi_match[] = {
+	{ "PNP0CA0", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, ucsi_acpi_match);
+
+static struct platform_driver ucsi_acpi_platform_driver = {
+	.driver = {
+		.name = "ucsi_acpi",
+		.acpi_match_table = ACPI_PTR(ucsi_acpi_match),
+	},
+	.probe = ucsi_acpi_probe,
+	.remove = ucsi_acpi_remove,
+};
+
+module_platform_driver(ucsi_acpi_platform_driver);
+
+MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("UCSI ACPI driver");