>From 6077a62f2865201ab6727ca7d628ee5e43aa57e1 Mon Sep 17 00:00:00 2001
From: Zhang Rui <rui.zhang@xxxxxxxxx>
Date: Fri, 24 Aug 2012 15:18:25 +0800
Subject: [RFC PATCH 5/6] ACPI: Introduce ACPI I2C controller enumeration
driver
This driver is able to
1) enumerate I2C controller via ACPI namespace
and register it as a platform device.
2) enumerate I2C slave devices via ACPI namespace.
Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
---
drivers/acpi/Makefile | 1 +
drivers/acpi/i2c_root.c | 229 +++++++++++++++++++++++++++++++++++++++++++
drivers/acpi/sysfs.c | 1 +
include/acpi/acpi_drivers.h | 1 +
4 files changed, 232 insertions(+), 0 deletions(-)
create mode 100644 drivers/acpi/i2c_root.c
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 4b65608..5b14f05 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -35,6 +35,7 @@ acpi-y += scan.o
acpi-y += processor_core.o
acpi-y += ec.o
acpi-y += gpio.o
+acpi-y += i2c_root.o
acpi-$(CONFIG_ACPI_DOCK) += dock.o
acpi-y += pci_root.o pci_link.o pci_irq.o pci_bind.o
acpi-y += power.o
diff --git a/drivers/acpi/i2c_root.c b/drivers/acpi/i2c_root.c
new file mode 100644
index 0000000..b9a042b
--- /dev/null
+++ b/drivers/acpi/i2c_root.c
@@ -0,0 +1,229 @@
+/*
+ * i2c_root.c - ACPI I2C controller Driver ($Revision: 40 $)
+ *
+ * Copyright (C) 2012 Intel Corp
+ * Copyright (C) 2012 Zhang Rui <rui.zhang@xxxxxxxxx>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * 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; version 2 of the License.
+ *
+ * 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. 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.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/platform_device.h>
+#include <linux/i2c.h>
+#include <linux/acpi.h>
+#include <linux/slab.h>
+#include <acpi/acpi_bus.h>
+#include <acpi/acpi_drivers.h>
+#include <acpi/apei.h>
+
+#define PREFIX "ACPI: "
+
+#define _COMPONENT ACPI_SPB_COMPONENT
+ACPI_MODULE_NAME("i2c_root");
+#define ACPI_I2C_ROOT_CLASS "i2c_root"
+#define ACPI_I2C_ROOT_DEVICE_NAME "I2C Controller"
+
+static int acpi_i2c_root_add(struct acpi_device *device);
+static int acpi_i2c_root_remove(struct acpi_device *device, int type);
+
+static const struct acpi_device_id root_device_ids[] = {
+ {"INT33B1", 0},
+ {"", 0},
+};
+
+MODULE_DEVICE_TABLE(acpi, root_device_ids);
+
+static struct acpi_driver acpi_i2c_root_driver = {
+ .name = "i2c_root",
+ .class = ACPI_I2C_ROOT_CLASS,
+ .ids = root_device_ids,
+ .ops = {
+ .add = acpi_i2c_root_add,
+ .remove = acpi_i2c_root_remove,
+ },
+};
+
+struct acpi_i2c_root {
+ struct acpi_device *device;
+ struct platform_device *pdev;
+ int busnum;
+ int slaves;
+ struct i2c_board_info *info;
+};
+
+static int add_slave(struct acpi_i2c_root *root, struct i2c_board_info *info)
+{
+ struct i2c_board_info *p;
+
+ if (!info)
+ return 0;
+
+ p = kzalloc(sizeof(*p) * (root->slaves + 1), GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+
+ memcpy(p, info, sizeof(*p));
+ if (root->info)
+ memcpy(p + 1, root->info, sizeof(*p) * root->slaves);
+
+ kfree(root->info);
+ root->info = p;
+ root->slaves++;
+ return 0;
+}
+
+static int register_slaves(struct acpi_i2c_root *root)
+{
+ return i2c_register_board_info(root->busnum, root->info, root->slaves);
+}
+
+/*
+ * The i2c info registering call back for each i2c slave device
+ */
+acpi_status __init i2c_enumerate_slave(acpi_handle handle, u32 level,
+ void *data, void **return_value)
+{
+ int result;
+ acpi_status status;
+ struct acpi_buffer buffer;
+ struct acpi_resource *resource;
+ struct acpi_resource_gpio *gpio;
+ struct acpi_resource_i2c_serialbus *i2c;
+ int i;
+ struct acpi_i2c_root *root = data;
+ struct i2c_board_info info;
+ struct acpi_device *device;
+
+ if (acpi_bus_get_device(handle, &device))
+ return AE_OK;
+
+ status = acpi_get_current_resources(handle, &buffer);
+ if (ACPI_FAILURE(status)) {
+ dev_err(&device->dev, "Failed to get ACPI resources\n");
+ return AE_OK;
+ }
+
+ for (i = 0; i < buffer.length; i += sizeof(struct acpi_resource)) {
+ resource = (struct acpi_resource *)(buffer.pointer + i);
+
+ switch (resource->type) {
+ case ACPI_RESOURCE_TYPE_GPIO:
+ gpio = &resource->data.gpio;
+
+ if (gpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT) {
+ result =
+ acpi_device_get_gpio_irq
+ (gpio->resource_source.string_ptr,
+ gpio->pin_table[0], &info.irq);
+ if (result)
+ dev_err(&device->dev,
+ "Failed to get IRQ\n");
+ }
+ break;
+ case ACPI_RESOURCE_TYPE_SERIAL_BUS:
+ i2c = &resource->data.i2c_serial_bus;
+
+ info.addr = i2c->slave_address;
+ break;
+ default:
+ break;
+ }
+ }
+
+ add_slave(root, &info);
+
+ kfree(buffer.pointer);
+ return AE_OK;
+}
+
+static int __devinit acpi_i2c_root_add(struct acpi_device *device)
+{
+ acpi_status status;
+ struct acpi_i2c_root *root;
+ struct resource *resources;
+ int result;
+
+ if (!device->pnp.unique_id) {
+ dev_err(&device->dev,
+ "Unsupported ACPI I2C controller. No UID\n");
+ return -ENODEV;
+ }
+
+ root = kzalloc(sizeof(struct acpi_i2c_root), GFP_KERNEL);
+ if (!root)
+ return -ENOMEM;
+
+ root->device = device;
+
+ kstrtoint(device->pnp.unique_id, 10, &root->busnum);
+
+ /* enumerate I2C controller */
+ root->pdev =
+ platform_device_alloc(acpi_device_hid(device), root->busnum);
+ if (!root->pdev) {
+ dev_err(&device->dev, "Failed to alloc platform device\n");
+ goto err;
+ }
+
+ result = acpi_get_generic_resources(device, &resources);
+ if (result < 0) {
+ dev_err(&device->dev, "Failed to get resources\n");
+ goto err;
+ }
+
+ platform_device_add_resources(root->pdev, resources, result);
+ platform_device_add(root->pdev);
+
+ /* enumerate I2C slave devices */
+ status = acpi_walk_namespace(ACPI_TYPE_DEVICE, root->device->handle, 1,
+ i2c_enumerate_slave, NULL, root, NULL);
+
+ if (ACPI_FAILURE(status)) {
+ dev_err(&root->device->dev, "i2c ACPI namespace walk error!\n");
+ kfree(root);
+ return -ENODEV;
+ }
+
+ register_slaves(root);
+
+ return 0;
+err:
+ kfree(root);
+ return -ENODEV;
+}
+
+static int acpi_i2c_root_remove(struct acpi_device *device, int type)
+{
+ struct acpi_i2c_root *root = acpi_driver_data(device);
+
+ kfree(root->info);
+ kfree(root);
+
+ return 0;
+}
+
+int __init acpi_i2c_root_init(void)
+{
+ return acpi_bus_register_driver(&acpi_i2c_root_driver);
+}
diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c
index 240a244..0e0c83c 100644
--- a/drivers/acpi/sysfs.c
+++ b/drivers/acpi/sysfs.c
@@ -63,6 +63,7 @@ static const struct acpi_dlayer acpi_debug_layers[] = {
ACPI_DEBUG_INIT(ACPI_MEMORY_DEVICE_COMPONENT),
ACPI_DEBUG_INIT(ACPI_VIDEO_COMPONENT),
ACPI_DEBUG_INIT(ACPI_PROCESSOR_COMPONENT),
+ ACPI_DEBUG_INIT(ACPI_SPB_COMPONENT),
};
static const struct acpi_dlevel acpi_debug_levels[] = {
diff --git a/include/acpi/acpi_drivers.h b/include/acpi/acpi_drivers.h
index b75a408..499376c 100644
--- a/include/acpi/acpi_drivers.h
+++ b/include/acpi/acpi_drivers.h
@@ -49,6 +49,7 @@
#define ACPI_MEMORY_DEVICE_COMPONENT 0x08000000
#define ACPI_VIDEO_COMPONENT 0x10000000
#define ACPI_PROCESSOR_COMPONENT 0x20000000
+#define ACPI_SPB_COMPONENT 0x40000000
/*
* _HID definitions
--
1.7.7.6
