Fixed MTP to work with TWRP

drivers/pci/hotplug/acpiphp_ibm.c

@@ -0,0 +1,487 @@
+/*
+ * ACPI PCI Hot Plug IBM Extension
+ *
+ * Copyright (C) 2004 Vernon Mauery <vernux@us.ibm.com>
+ * Copyright (C) 2004 IBM Corp.
+ *
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Send feedback to <vernux@us.ibm.com>
+ *
+ */
+
+#define pr_fmt(fmt) "acpiphp_ibm: " fmt
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sysfs.h>
+#include <linux/kobject.h>
+#include <linux/moduleparam.h>
+#include <linux/pci.h>
+#include <asm/uaccess.h>
+
+#include "acpiphp.h"
+#include "../pci.h"
+
+#define DRIVER_VERSION	"1.0.1"
+#define DRIVER_AUTHOR	"Irene Zubarev <zubarev@us.ibm.com>, Vernon Mauery <vernux@us.ibm.com>"
+#define DRIVER_DESC	"ACPI Hot Plug PCI Controller Driver IBM extension"
+
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRIVER_VERSION);
+
+#define FOUND_APCI 0x61504349
+/* these are the names for the IBM ACPI pseudo-device */
+#define IBM_HARDWARE_ID1 "IBM37D0"
+#define IBM_HARDWARE_ID2 "IBM37D4"
+
+#define hpslot_to_sun(A) (((struct slot *)((A)->private))->sun)
+
+/* union apci_descriptor - allows access to the
+ * various device descriptors that are embedded in the
+ * aPCI table
+ */
+union apci_descriptor {
+	struct {
+		char sig[4];
+		u8   len;
+	} header;
+	struct {
+		u8  type;
+		u8  len;
+		u16 slot_id;
+		u8  bus_id;
+		u8  dev_num;
+		u8  slot_num;
+		u8  slot_attr[2];
+		u8  attn;
+		u8  status[2];
+		u8  sun;
+		u8  res[3];
+	} slot;
+	struct {
+		u8 type;
+		u8 len;
+	} generic;
+};
+
+/* struct notification - keeps info about the device
+ * that cause the ACPI notification event
+ */
+struct notification {
+	struct acpi_device *device;
+	u8                  event;
+};
+
+static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status);
+static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status);
+static void ibm_handle_events(acpi_handle handle, u32 event, void *context);
+static int ibm_get_table_from_acpi(char **bufp);
+static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj,
+				   struct bin_attribute *bin_attr,
+				   char *buffer, loff_t pos, size_t size);
+static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
+		u32 lvl, void *context, void **rv);
+static int __init ibm_acpiphp_init(void);
+static void __exit ibm_acpiphp_exit(void);
+
+static acpi_handle ibm_acpi_handle;
+static struct notification ibm_note;
+static struct bin_attribute ibm_apci_table_attr = {
+	    .attr = {
+		    .name = "apci_table",
+		    .mode = S_IRUGO,
+	    },
+	    .read = ibm_read_apci_table,
+	    .write = NULL,
+};
+static struct acpiphp_attention_info ibm_attention_info =
+{
+	.set_attn = ibm_set_attention_status,
+	.get_attn = ibm_get_attention_status,
+	.owner = THIS_MODULE,
+};
+
+/**
+ * ibm_slot_from_id - workaround for bad ibm hardware
+ * @id: the slot number that linux refers to the slot by
+ *
+ * Description: This method returns the aCPI slot descriptor
+ * corresponding to the Linux slot number.  This descriptor
+ * has info about the aPCI slot id and attention status.
+ * This descriptor must be freed using kfree when done.
+ */
+static union apci_descriptor *ibm_slot_from_id(int id)
+{
+	int ind = 0, size;
+	union apci_descriptor *ret = NULL, *des;
+	char *table;
+
+	size = ibm_get_table_from_acpi(&table);
+	des = (union apci_descriptor *)table;
+	if (memcmp(des->header.sig, "aPCI", 4) != 0)
+		goto ibm_slot_done;
+
+	des = (union apci_descriptor *)&table[ind += des->header.len];
+	while (ind < size && (des->generic.type != 0x82 ||
+			des->slot.slot_num != id)) {
+		des = (union apci_descriptor *)&table[ind += des->generic.len];
+	}
+
+	if (ind < size && des->slot.slot_num == id)
+		ret = des;
+
+ibm_slot_done:
+	if (ret) {
+		ret = kmalloc(sizeof(union apci_descriptor), GFP_KERNEL);
+		memcpy(ret, des, sizeof(union apci_descriptor));
+	}
+	kfree(table);
+	return ret;
+}
+
+/**
+ * ibm_set_attention_status - callback method to set the attention LED
+ * @slot: the hotplug_slot to work with
+ * @status: what to set the LED to (0 or 1)
+ *
+ * Description: This method is registered with the acpiphp module as a
+ * callback to do the device specific task of setting the LED status.
+ */
+static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status)
+{
+	union acpi_object args[2];
+	struct acpi_object_list params = { .pointer = args, .count = 2 };
+	acpi_status stat;
+	unsigned long long rc;
+	union apci_descriptor *ibm_slot;
+
+	ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot));
+
+	pr_debug("%s: set slot %d (%d) attention status to %d\n", __func__,
+			ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
+			(status ? 1 : 0));
+
+	args[0].type = ACPI_TYPE_INTEGER;
+	args[0].integer.value = ibm_slot->slot.slot_id;
+	args[1].type = ACPI_TYPE_INTEGER;
+	args[1].integer.value = (status) ? 1 : 0;
+
+	kfree(ibm_slot);
+
+	stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", &params, &rc);
+	if (ACPI_FAILURE(stat)) {
+		pr_err("APLS evaluation failed:  0x%08x\n", stat);
+		return -ENODEV;
+	} else if (!rc) {
+		pr_err("APLS method failed:  0x%08llx\n", rc);
+		return -ERANGE;
+	}
+	return 0;
+}
+
+/**
+ * ibm_get_attention_status - callback method to get attention LED status
+ * @slot: the hotplug_slot to work with
+ * @status: returns what the LED is set to (0 or 1)
+ *
+ * Description: This method is registered with the acpiphp module as a
+ * callback to do the device specific task of getting the LED status.
+ *
+ * Because there is no direct method of getting the LED status directly
+ * from an ACPI call, we read the aPCI table and parse out our
+ * slot descriptor to read the status from that.
+ */
+static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status)
+{
+	union apci_descriptor *ibm_slot;
+
+	ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot));
+
+	if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08)
+		*status = 1;
+	else
+		*status = 0;
+
+	pr_debug("%s: get slot %d (%d) attention status is %d\n", __func__,
+			ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
+			*status);
+
+	kfree(ibm_slot);
+	return 0;
+}
+
+/**
+ * ibm_handle_events - listens for ACPI events for the IBM37D0 device
+ * @handle: an ACPI handle to the device that caused the event
+ * @event: the event info (device specific)
+ * @context: passed context (our notification struct)
+ *
+ * Description: This method is registered as a callback with the ACPI
+ * subsystem it is called when this device has an event to notify the OS of.
+ *
+ * The events actually come from the device as two events that get
+ * synthesized into one event with data by this function.  The event
+ * ID comes first and then the slot number that caused it.  We report
+ * this as one event to the OS.
+ *
+ * From section 5.6.2.2 of the ACPI 2.0 spec, I understand that the OSPM will
+ * only re-enable the interrupt that causes this event AFTER this method
+ * has returned, thereby enforcing serial access for the notification struct.
+ */
+static void ibm_handle_events(acpi_handle handle, u32 event, void *context)
+{
+	u8 detail = event & 0x0f;
+	u8 subevent = event & 0xf0;
+	struct notification *note = context;
+
+	pr_debug("%s: Received notification %02x\n", __func__, event);
+
+	if (subevent == 0x80) {
+		pr_debug("%s: generating bus event\n", __func__);
+		acpi_bus_generate_netlink_event(note->device->pnp.device_class,
+						  dev_name(&note->device->dev),
+						  note->event, detail);
+	} else
+		note->event = event;
+}
+
+/**
+ * ibm_get_table_from_acpi - reads the APLS buffer from ACPI
+ * @bufp: address to pointer to allocate for the table
+ *
+ * Description: This method reads the APLS buffer in from ACPI and
+ * stores the "stripped" table into a single buffer
+ * it allocates and passes the address back in bufp.
+ *
+ * If NULL is passed in as buffer, this method only calculates
+ * the size of the table and returns that without filling
+ * in the buffer.
+ *
+ * Returns < 0 on error or the size of the table on success.
+ */
+static int ibm_get_table_from_acpi(char **bufp)
+{
+	union acpi_object *package;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	acpi_status status;
+	char *lbuf = NULL;
+	int i, size = -EIO;
+
+	status = acpi_evaluate_object(ibm_acpi_handle, "APCI", NULL, &buffer);
+	if (ACPI_FAILURE(status)) {
+		pr_err("%s:  APCI evaluation failed\n", __func__);
+		return -ENODEV;
+	}
+
+	package = (union acpi_object *) buffer.pointer;
+	if (!(package) ||
+			(package->type != ACPI_TYPE_PACKAGE) ||
+			!(package->package.elements)) {
+		pr_err("%s:  Invalid APCI object\n", __func__);
+		goto read_table_done;
+	}
+
+	for (size = 0, i = 0; i < package->package.count; i++) {
+		if (package->package.elements[i].type != ACPI_TYPE_BUFFER) {
+			pr_err("%s:  Invalid APCI element %d\n", __func__, i);
+			goto read_table_done;
+		}
+		size += package->package.elements[i].buffer.length;
+	}
+
+	if (bufp == NULL)
+		goto read_table_done;
+
+	lbuf = kzalloc(size, GFP_KERNEL);
+	pr_debug("%s: element count: %i, ASL table size: %i, &table = 0x%p\n",
+			__func__, package->package.count, size, lbuf);
+
+	if (lbuf) {
+		*bufp = lbuf;
+	} else {
+		size = -ENOMEM;
+		goto read_table_done;
+	}
+
+	size = 0;
+	for (i=0; i<package->package.count; i++) {
+		memcpy(&lbuf[size],
+				package->package.elements[i].buffer.pointer,
+				package->package.elements[i].buffer.length);
+		size += package->package.elements[i].buffer.length;
+	}
+
+read_table_done:
+	kfree(buffer.pointer);
+	return size;
+}
+
+/**
+ * ibm_read_apci_table - callback for the sysfs apci_table file
+ * @filp: the open sysfs file
+ * @kobj: the kobject this binary attribute is a part of
+ * @bin_attr: struct bin_attribute for this file
+ * @buffer: the kernel space buffer to fill
+ * @pos: the offset into the file
+ * @size: the number of bytes requested
+ *
+ * Description: Gets registered with sysfs as the reader callback
+ * to be executed when /sys/bus/pci/slots/apci_table gets read.
+ *
+ * Since we don't get notified on open and close for this file,
+ * things get really tricky here...
+ * our solution is to only allow reading the table in all at once.
+ */
+static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj,
+				   struct bin_attribute *bin_attr,
+				   char *buffer, loff_t pos, size_t size)
+{
+	int bytes_read = -EINVAL;
+	char *table = NULL;
+
+	pr_debug("%s: pos = %d, size = %zd\n", __func__, (int)pos, size);
+
+	if (pos == 0) {
+		bytes_read = ibm_get_table_from_acpi(&table);
+		if (bytes_read > 0 && bytes_read <= size)
+			memcpy(buffer, table, bytes_read);
+		kfree(table);
+	}
+	return bytes_read;
+}
+
+/**
+ * ibm_find_acpi_device - callback to find our ACPI device
+ * @handle: the ACPI handle of the device we are inspecting
+ * @lvl: depth into the namespace tree
+ * @context: a pointer to our handle to fill when we find the device
+ * @rv: a return value to fill if desired
+ *
+ * Description: Used as a callback when calling acpi_walk_namespace
+ * to find our device.  When this method returns non-zero
+ * acpi_walk_namespace quits its search and returns our value.
+ */
+static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
+		u32 lvl, void *context, void **rv)
+{
+	acpi_handle *phandle = (acpi_handle *)context;
+	acpi_status status;
+	struct acpi_device_info *info;
+	int retval = 0;
+
+	status = acpi_get_object_info(handle, &info);
+	if (ACPI_FAILURE(status)) {
+		pr_err("%s:  Failed to get device information status=0x%x\n",
+			__func__, status);
+		return retval;
+	}
+
+	if (info->current_status && (info->valid & ACPI_VALID_HID) &&
+			(!strcmp(info->hardware_id.string, IBM_HARDWARE_ID1) ||
+			 !strcmp(info->hardware_id.string, IBM_HARDWARE_ID2))) {
+		pr_debug("found hardware: %s, handle: %p\n",
+			info->hardware_id.string, handle);
+		*phandle = handle;
+		/* returning non-zero causes the search to stop
+		 * and returns this value to the caller of
+		 * acpi_walk_namespace, but it also causes some warnings
+		 * in the acpi debug code to print...
+		 */
+		retval = FOUND_APCI;
+	}
+	kfree(info);
+	return retval;
+}
+
+static int __init ibm_acpiphp_init(void)
+{
+	int retval = 0;
+	acpi_status status;
+	struct acpi_device *device;
+	struct kobject *sysdir = &pci_slots_kset->kobj;
+
+	pr_debug("%s\n", __func__);
+
+	if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+			ACPI_UINT32_MAX, ibm_find_acpi_device, NULL,
+			&ibm_acpi_handle, NULL) != FOUND_APCI) {
+		pr_err("%s: acpi_walk_namespace failed\n", __func__);
+		retval = -ENODEV;
+		goto init_return;
+	}
+	pr_debug("%s: found IBM aPCI device\n", __func__);
+	if (acpi_bus_get_device(ibm_acpi_handle, &device)) {
+		pr_err("%s: acpi_bus_get_device failed\n", __func__);
+		retval = -ENODEV;
+		goto init_return;
+	}
+	if (acpiphp_register_attention(&ibm_attention_info)) {
+		retval = -ENODEV;
+		goto init_return;
+	}
+
+	ibm_note.device = device;
+	status = acpi_install_notify_handler(ibm_acpi_handle,
+			ACPI_DEVICE_NOTIFY, ibm_handle_events,
+			&ibm_note);
+	if (ACPI_FAILURE(status)) {
+		pr_err("%s: Failed to register notification handler\n",
+				__func__);
+		retval = -EBUSY;
+		goto init_cleanup;
+	}
+
+	ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL);
+	retval = sysfs_create_bin_file(sysdir, &ibm_apci_table_attr);
+
+	return retval;
+
+init_cleanup:
+	acpiphp_unregister_attention(&ibm_attention_info);
+init_return:
+	return retval;
+}
+
+static void __exit ibm_acpiphp_exit(void)
+{
+	acpi_status status;
+	struct kobject *sysdir = &pci_slots_kset->kobj;
+
+	pr_debug("%s\n", __func__);
+
+	if (acpiphp_unregister_attention(&ibm_attention_info))
+		pr_err("%s: attention info deregistration failed", __func__);
+
+	status = acpi_remove_notify_handler(
+			   ibm_acpi_handle,
+			   ACPI_DEVICE_NOTIFY,
+			   ibm_handle_events);
+	if (ACPI_FAILURE(status))
+		pr_err("%s: Notification handler removal failed\n", __func__);
+	/* remove the /sys entries */
+	sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr);
+}
+
+module_init(ibm_acpiphp_init);
+module_exit(ibm_acpiphp_exit);