This patch adds support to load a custom ACPI table that describes
devices connected via the DLN2 USB to I2C/SPI/GPIO bridge.
The ACPI table is loaded at runtime as firmware with the name
dln2.aml, it looks for an ACPI device entry with _HID set to
"DLN20000" and makes it the ACPI companion for DLN2 USB sub-drivers.
It is sort of a hack due to the "../acpi/internal.h" and
"../usb/core/usb.h" includes and perhaps something more generic would
be more appropriate. Any suggestions to the right direction are kindly
appreciated.
Signed-off-by: Octavian Purdila <octavian.purdila@xxxxxxxxx>
---
Documentation/acpi/dln2-acpi.txt | 48 ++++++++++++++++++
drivers/mfd/Kconfig | 11 +++++
drivers/mfd/Makefile | 1 +
drivers/mfd/dln2-acpi.c | 103 +++++++++++++++++++++++++++++++++++++++
drivers/mfd/dln2.c | 6 +--
drivers/mfd/dln2.h | 9 ++++
6 files changed, 173 insertions(+), 5 deletions(-)
create mode 100644 Documentation/acpi/dln2-acpi.txt
create mode 100644 drivers/mfd/dln2-acpi.c
create mode 100644 drivers/mfd/dln2.h
diff --git a/Documentation/acpi/dln2-acpi.txt b/Documentation/acpi/dln2-acpi.txt
new file mode 100644
index 0000000..c099241
--- /dev/null
+++ b/Documentation/acpi/dln2-acpi.txt
@@ -0,0 +1,48 @@
+Diolan DLN2 custom APCI table
+
+The Diolan DLN2 is an USB to I2C/SPI/GPIO bridge and as such it can be used to
+connect to various I2C or SPI devices. Because these busses lack an enumeration
+protocol, the driver obtains various information about the device (such as I2C
+address and GPIO pins) from either ACPI or device tree.
+
+To allow using such devices connect to the DLN2 bridge to their full extend
+(e.g. interrupt mode), if CONFIG_MFD_DLN2_ACPI option has been compiled in the
+kernel, the user can define a custom ACPI table that will be dynamically loaded
+at boot time from firmware paths. The ACPI table filename must be dln2.aml and
+it must contain a root device with _HID set "DLN20000".
+
+Here is a example of how the ACPI table should look like:
+
+DefinitionBlock ("ssdt.aml", "SSDT", 1, "INTEL ", "CpuDptf", 0x00000003)
+{
+ Device (DLN0)
+ {
+ Name (_ADR, Zero)
+ Name (_HID, "DLN2000")
+
+ Device (STAC)
+ {
+ Name (_ADR, Zero)
+ Name (_HID, "BMC150A")
+ Name (_CID, "INTACCL")
+ Name (_UID, One)
+
+ Method (_CRS, 0, Serialized)
+ {
+ Name (RBUF, ResourceTemplate ()
+ {
+ I2cSerialBus (0x0010, ControllerInitiated, 0x00061A80,
+ AddressingMode7Bit, "\\DLN0",
+ 0x00, ResourceConsumer, ,)
+
+ GpioInt (Level, ActiveHigh, Exclusive, PullDown, 0x0000,
+ "\\DLN0", 0x00, ResourceConsumer, , )
+ { // Pin list
+ 0
+ }
+ })
+ Return (RBUF)
+ }
+ }
+ }
+}
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 2e6b731..b810195 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -205,6 +205,17 @@ config MFD_DLN2
etc. must be enabled in order to use the functionality of
the device.
+config MFD_DLN2_ACPI
+ bool "Diolan DLN2 ACPI support"
+ depends on MFD_DLN2 && ACPI
+ default n
+ help
+ Say yes here to add ACPI support to DLN2 which allows loading a custom
+ ACPI table to describe devices between the DLN2 I2C or SPI bridge as
+ well as GPIO support for those devices. See
+ Documentation/acpi/dln2-acpi.txt for more information.
+
+
config MFD_MC13XXX
tristate
depends on (SPI_MASTER || I2C)
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 53467e2..dbe1f3f 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -176,6 +176,7 @@ obj-$(CONFIG_MFD_IPAQ_MICRO) += ipaq-micro.o
obj-$(CONFIG_MFD_MENF21BMC) += menf21bmc.o
obj-$(CONFIG_MFD_HI6421_PMIC) += hi6421-pmic-core.o
obj-$(CONFIG_MFD_DLN2) += dln2.o
+obj-$(CONFIG_MFD_DLN2_ACPI) += dln2-acpi.o
intel-soc-pmic-objs := intel_soc_pmic_core.o intel_soc_pmic_crc.o
obj-$(CONFIG_INTEL_SOC_PMIC) += intel-soc-pmic.o
diff --git a/drivers/mfd/dln2-acpi.c b/drivers/mfd/dln2-acpi.c
new file mode 100644
index 0000000..8c99769
--- /dev/null
+++ b/drivers/mfd/dln2-acpi.c
@@ -0,0 +1,103 @@
+#define pr_fmt(fmt) "dln2-acpi: " fmt
+
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/acpi.h>
+#include <linux/firmware.h>
+#include "../acpi/internal.h"
+#include "../usb/core/usb.h"
+#include "dln2.h"
+
+static acpi_handle dln2_acpi_handle = NULL;
+static const struct firmware *dln2_acpi;
+
+static bool dln2_acpi_bus_match(struct device *dev)
+{
+ struct usb_interface *intf;
+ struct usb_device *udev;
+ u16 idVendor, idProduct;
+ int i;
+
+ if (is_usb_endpoint(dev) || !dev->parent ||
+ !is_usb_interface(dev->parent))
+ return false;
+
+ intf = to_usb_interface(dev->parent);
+ udev = interface_to_usbdev(intf);
+ idVendor = le16_to_cpu(udev->descriptor.idVendor);
+ idProduct = le16_to_cpu(udev->descriptor.idProduct);
+
+ for (i = 0; i < ARRAY_SIZE(dln2_table); i++)
+ if (idVendor == dln2_table[i].idVendor &&
+ idProduct == dln2_table[i].idProduct)
+ return true;
+
+ return false;
+}
+
+static struct acpi_device *dln2_acpi_find_companion(struct device *dev)
+{
+ struct acpi_device *adev;
+ int ret;
+
+ ret = acpi_bus_get_device(dln2_acpi_handle, &adev);
+ if (ret) {
+ pr_err("failed to get device: %d\n", ret);
+ return NULL;
+ }
+
+ return adev;
+}
+
+static struct acpi_bus_type dln2_acpi_bus = {
+ .name = "DNL2",
+ .match = dln2_acpi_bus_match,
+ .find_companion = dln2_acpi_find_companion,
+};
+
+static acpi_status dln2_find_acpi_handle(acpi_handle handle, u32 level,
+ void *ctxt, void **retv)
+{
+ acpi_handle *dln2_handle = (acpi_handle *)retv;
+
+ *dln2_handle = handle;
+
+ return AE_CTRL_TERMINATE;
+}
+
+static int dln2_acpi_init(void)
+{
+ int ret;
+
+ request_firmware_direct(&dln2_acpi, "dln2.aml", NULL);
+ if (dln2_acpi) {
+ struct acpi_table_header *acpi_table = (void *)dln2_acpi->data;
+
+ ret = acpi_load_table(acpi_table);
+ if (ret) {
+ pr_err("invalid ACPI table\n");
+ release_firmware(dln2_acpi);
+ }
+ }
+
+ acpi_get_devices("DLN20000", dln2_find_acpi_handle, NULL, &dln2_acpi_handle);
+ if (!dln2_acpi_handle)
+ return -ENODEV;
+
+ if (dln2_acpi)
+ acpi_bus_scan(dln2_acpi_handle);
+
+ return register_acpi_bus_type(&dln2_acpi_bus);
+}
+
+static void dln2_acpi_exit(void)
+{
+ release_firmware(dln2_acpi);
+ unregister_acpi_bus_type(&dln2_acpi_bus);
+}
+
+module_init(dln2_acpi_init);
+module_exit(dln2_acpi_exit);
diff --git a/drivers/mfd/dln2.c b/drivers/mfd/dln2.c
index 08c403c..62120e7 100644
--- a/drivers/mfd/dln2.c
+++ b/drivers/mfd/dln2.c
@@ -23,6 +23,7 @@
#include <linux/mfd/core.h>
#include <linux/mfd/dln2.h>
#include <linux/rculist.h>
+#include "dln2.h"
struct dln2_header {
__le16 size;
@@ -768,11 +769,6 @@ out_cleanup:
return ret;
}
-static const struct usb_device_id dln2_table[] = {
- { USB_DEVICE(0xa257, 0x2013) },
- { }
-};
-
MODULE_DEVICE_TABLE(usb, dln2_table);
static int dln2_suspend(struct usb_interface *iface, pm_message_t message)
diff --git a/drivers/mfd/dln2.h b/drivers/mfd/dln2.h
new file mode 100644
index 0000000..1ed4272
--- /dev/null
+++ b/drivers/mfd/dln2.h
@@ -0,0 +1,9 @@
+#ifndef _MFD_DLN2_H
+#define _MFD_DLN2_H
+
+static const struct usb_device_id dln2_table[] = {
+ { USB_DEVICE(0xa257, 0x2013) },
+ { }
+};
+
+#endif /* _MFD_DLN2_H */
--
1.9.1
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