enable AST2600 I3C

This commit ports I3C related changes from Aspeed SDK v00.05.05.
It also includes Vitor's I3C cdev implementation which isn't
upstreamed yet so it should be refined later.

Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
Signed-off-by: Vitor Soares <soares@synopsys.com>
Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@intel.com>

8 files changed, 545 insertions, 1 deletions

diff --git a/drivers/i3c/Kconfig b/drivers/i3c/Kconfig
index 30a441506f61..01642768ab5f 100644
--- a/drivers/i3c/Kconfig
+++ b/drivers/i3c/Kconfig
@@ -20,5 +20,20 @@ menuconfig I3C
 	  will be called i3c.
 
 if I3C
+
+config I3CDEV
+	tristate "I3C device interface"
+	depends on I3C
+	help
+	  Say Y here to use i3c-* device files, usually found in the /dev
+	  directory on your system.  They make it possible to have user-space
+	  programs use the I3C devices.
+
+	  This support is also available as a module.  If so, the module
+	  will be called i3cdev.
+
+	  Note that this application programming interface is EXPERIMENTAL
+	  and hence SUBJECT TO CHANGE WITHOUT NOTICE while it stabilizes.
+
 source "drivers/i3c/master/Kconfig"
 endif # I3C
diff --git a/drivers/i3c/Makefile b/drivers/i3c/Makefile
index 11982efbc6d9..606d422841b2 100644
--- a/drivers/i3c/Makefile
+++ b/drivers/i3c/Makefile
@@ -1,4 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
 i3c-y				:= device.o master.o
 obj-$(CONFIG_I3C)		+= i3c.o
+obj-$(CONFIG_I3CDEV)		+= i3cdev.o
 obj-$(CONFIG_I3C)		+= master/
diff --git a/drivers/i3c/i3cdev.c b/drivers/i3c/i3cdev.c
new file mode 100644
index 000000000000..07f5641a902d
--- /dev/null
+++ b/drivers/i3c/i3cdev.c
@@ -0,0 +1,428 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019 Synopsys, Inc. and/or its affiliates.
+ *
+ * Author: Vitor Soares <soares@synopsys.com>
+ */
+
+#include <linux/cdev.h>
+#include <linux/compat.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+#include <linux/i3c/i3cdev.h>
+
+#include "internals.h"
+
+struct i3cdev_data {
+	struct list_head list;
+	struct i3c_device *i3c;
+	struct cdev cdev;
+	struct device *dev;
+	int id;
+};
+
+static DEFINE_IDA(i3cdev_ida);
+static dev_t i3cdev_number;
+#define I3C_MINORS 16 /* 16 I3C devices supported for now */
+
+static LIST_HEAD(i3cdev_list);
+static DEFINE_SPINLOCK(i3cdev_list_lock);
+
+static struct i3cdev_data *i3cdev_get_by_i3c(struct i3c_device *i3c)
+{
+	struct i3cdev_data *i3cdev;
+
+	spin_lock(&i3cdev_list_lock);
+	list_for_each_entry(i3cdev, &i3cdev_list, list) {
+		if (i3cdev->i3c == i3c)
+			goto found;
+	}
+
+	i3cdev = NULL;
+
+found:
+	spin_unlock(&i3cdev_list_lock);
+	return i3cdev;
+}
+
+static struct i3cdev_data *get_free_i3cdev(struct i3c_device *i3c)
+{
+	struct i3cdev_data *i3cdev;
+	int id;
+
+	id = ida_simple_get(&i3cdev_ida, 0, I3C_MINORS, GFP_KERNEL);
+	if (id < 0) {
+		pr_err("i3cdev: no minor number available!\n");
+		return ERR_PTR(id);
+	}
+
+	i3cdev = kzalloc(sizeof(*i3cdev), GFP_KERNEL);
+	if (!i3cdev) {
+		ida_simple_remove(&i3cdev_ida, id);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	i3cdev->i3c = i3c;
+	i3cdev->id = id;
+
+	spin_lock(&i3cdev_list_lock);
+	list_add_tail(&i3cdev->list, &i3cdev_list);
+	spin_unlock(&i3cdev_list_lock);
+
+	return i3cdev;
+}
+
+static void put_i3cdev(struct i3cdev_data *i3cdev)
+{
+	spin_lock(&i3cdev_list_lock);
+	list_del(&i3cdev->list);
+	spin_unlock(&i3cdev_list_lock);
+	kfree(i3cdev);
+}
+
+static ssize_t
+i3cdev_read(struct file *file, char __user *buf, size_t count, loff_t *f_pos)
+{
+	struct i3c_device *i3c = file->private_data;
+	struct i3c_priv_xfer xfers = {
+		.rnw = true,
+		.len = count,
+	};
+	char *tmp;
+	int ret;
+
+	tmp = kzalloc(count, GFP_KERNEL);
+	if (!tmp)
+		return -ENOMEM;
+
+	xfers.data.in = tmp;
+
+	dev_dbg(&i3c->dev, "Reading %zu bytes.\n", count);
+
+	ret = i3c_device_do_priv_xfers(i3c, &xfers, 1);
+	if (!ret)
+		ret = copy_to_user(buf, tmp, count) ? -EFAULT : ret;
+
+	kfree(tmp);
+	return ret;
+}
+
+static ssize_t
+i3cdev_write(struct file *file, const char __user *buf, size_t count,
+	     loff_t *f_pos)
+{
+	struct i3c_device *i3c = file->private_data;
+	struct i3c_priv_xfer xfers = {
+		.rnw = false,
+		.len = count,
+	};
+	char *tmp;
+	int ret;
+
+	tmp = memdup_user(buf, count);
+	if (IS_ERR(tmp))
+		return PTR_ERR(tmp);
+
+	xfers.data.out = tmp;
+
+	dev_dbg(&i3c->dev, "Writing %zu bytes.\n", count);
+
+	ret = i3c_device_do_priv_xfers(i3c, &xfers, 1);
+	kfree(tmp);
+	return (!ret) ? count : ret;
+}
+
+static int
+i3cdev_do_priv_xfer(struct i3c_device *dev, struct i3c_ioc_priv_xfer *xfers,
+		    unsigned int nxfers)
+{
+	struct i3c_priv_xfer *k_xfers;
+	u8 **data_ptrs;
+	int i, ret = 0;
+
+	k_xfers = kcalloc(nxfers, sizeof(*k_xfers), GFP_KERNEL);
+	if (!k_xfers)
+		return -ENOMEM;
+
+	data_ptrs = kcalloc(nxfers, sizeof(*data_ptrs), GFP_KERNEL);
+	if (!data_ptrs) {
+		ret = -ENOMEM;
+		goto err_free_k_xfer;
+	}
+
+	for (i = 0; i < nxfers; i++) {
+		data_ptrs[i] = memdup_user((const u8 __user *)
+					   (uintptr_t)xfers[i].data,
+					   xfers[i].len);
+		if (IS_ERR(data_ptrs[i])) {
+			ret = PTR_ERR(data_ptrs[i]);
+			break;
+		}
+
+		k_xfers[i].len = xfers[i].len;
+		if (xfers[i].rnw) {
+			k_xfers[i].rnw = true;
+			k_xfers[i].data.in = data_ptrs[i];
+		} else {
+			k_xfers[i].rnw = false;
+			k_xfers[i].data.out = data_ptrs[i];
+		}
+	}
+
+	if (ret < 0) {
+		i--;
+		goto err_free_mem;
+	}
+
+	ret = i3c_device_do_priv_xfers(dev, k_xfers, nxfers);
+	if (ret)
+		goto err_free_mem;
+
+	for (i = 0; i < nxfers; i++) {
+		if (xfers[i].rnw) {
+			if (copy_to_user((void __user *)(uintptr_t)xfers[i].data,
+					 data_ptrs[i], xfers[i].len))
+				ret = -EFAULT;
+		}
+	}
+
+err_free_mem:
+	for (; i >= 0; i--)
+		kfree(data_ptrs[i]);
+	kfree(data_ptrs);
+err_free_k_xfer:
+	kfree(k_xfers);
+	return ret;
+}
+
+static struct i3c_ioc_priv_xfer *
+i3cdev_get_ioc_priv_xfer(unsigned int cmd, struct i3c_ioc_priv_xfer *u_xfers,
+			 unsigned int *nxfers)
+{
+	u32 tmp = _IOC_SIZE(cmd);
+
+	if ((tmp % sizeof(struct i3c_ioc_priv_xfer)) != 0)
+		return ERR_PTR(-EINVAL);
+
+	*nxfers = tmp / sizeof(struct i3c_ioc_priv_xfer);
+	if (*nxfers == 0)
+		return NULL;
+
+	return memdup_user(u_xfers, tmp);
+}
+
+static int
+i3cdev_ioc_priv_xfer(struct i3c_device *i3c, unsigned int cmd,
+		     struct i3c_ioc_priv_xfer *u_xfers)
+{
+	struct i3c_ioc_priv_xfer *k_xfers;
+	unsigned int nxfers;
+	int ret;
+
+	k_xfers = i3cdev_get_ioc_priv_xfer(cmd, u_xfers, &nxfers);
+	if (IS_ERR_OR_NULL(k_xfers))
+		return PTR_ERR(k_xfers);
+
+	ret = i3cdev_do_priv_xfer(i3c, k_xfers, nxfers);
+
+	kfree(k_xfers);
+
+	return ret;
+}
+
+static long
+i3cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct i3c_device *i3c = file->private_data;
+
+	dev_dbg(&i3c->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n", cmd, arg);
+
+	if (_IOC_TYPE(cmd) != I3C_DEV_IOC_MAGIC)
+		return -ENOTTY;
+
+	/* Check command number and direction */
+	if (_IOC_NR(cmd) == _IOC_NR(I3C_IOC_PRIV_XFER(0)) &&
+	    _IOC_DIR(cmd) == (_IOC_READ | _IOC_WRITE))
+		return i3cdev_ioc_priv_xfer(i3c, cmd,
+					(struct i3c_ioc_priv_xfer __user *)arg);
+
+	return 0;
+}
+
+static int i3cdev_open(struct inode *inode, struct file *file)
+{
+	struct i3cdev_data *i3cdev = container_of(inode->i_cdev,
+						  struct i3cdev_data,
+						  cdev);
+
+	file->private_data = i3cdev->i3c;
+
+	return 0;
+}
+
+static int i3cdev_release(struct inode *inode, struct file *file)
+{
+	file->private_data = NULL;
+
+	return 0;
+}
+
+static const struct file_operations i3cdev_fops = {
+	.owner		= THIS_MODULE,
+	.read		= i3cdev_read,
+	.write		= i3cdev_write,
+	.unlocked_ioctl	= i3cdev_ioctl,
+	.open		= i3cdev_open,
+	.release	= i3cdev_release,
+};
+
+/* ------------------------------------------------------------------------- */
+
+static struct class *i3cdev_class;
+
+static int i3cdev_attach(struct device *dev, void *dummy)
+{
+	struct i3cdev_data *i3cdev;
+	struct i3c_device *i3c;
+	int res;
+
+	if (dev->type == &i3c_masterdev_type || dev->driver)
+		return 0;
+
+	i3c = dev_to_i3cdev(dev);
+
+	/* Get a device */
+	i3cdev = get_free_i3cdev(i3c);
+	if (IS_ERR(i3cdev))
+		return PTR_ERR(i3cdev);
+
+	cdev_init(&i3cdev->cdev, &i3cdev_fops);
+	i3cdev->cdev.owner = THIS_MODULE;
+	res = cdev_add(&i3cdev->cdev,
+		       MKDEV(MAJOR(i3cdev_number), i3cdev->id), 1);
+	if (res)
+		goto error_cdev;
+
+	/* register this i3c device with the driver core */
+	i3cdev->dev = device_create(i3cdev_class, &i3c->dev,
+				    MKDEV(MAJOR(i3cdev_number), i3cdev->id),
+				    NULL, "i3c-%s", dev_name(&i3c->dev));
+	if (IS_ERR(i3cdev->dev)) {
+		res = PTR_ERR(i3cdev->dev);
+		goto error;
+	}
+	pr_debug("i3cdev: I3C device [%s] registered as minor %d\n",
+		 dev_name(&i3c->dev), i3cdev->id);
+	return 0;
+
+error:
+	cdev_del(&i3cdev->cdev);
+error_cdev:
+	put_i3cdev(i3cdev);
+	return res;
+}
+
+static int i3cdev_detach(struct device *dev, void *dummy)
+{
+	struct i3cdev_data *i3cdev;
+	struct i3c_device *i3c;
+
+	if (dev->type == &i3c_masterdev_type)
+		return 0;
+
+	i3c = dev_to_i3cdev(dev);
+
+	i3cdev = i3cdev_get_by_i3c(i3c);
+	if (!i3cdev)
+		return 0;
+
+	cdev_del(&i3cdev->cdev);
+	device_destroy(i3cdev_class, MKDEV(MAJOR(i3cdev_number), i3cdev->id));
+	ida_simple_remove(&i3cdev_ida, i3cdev->id);
+	put_i3cdev(i3cdev);
+
+	pr_debug("i3cdev: device [%s] unregistered\n", dev_name(&i3c->dev));
+
+	return 0;
+}
+
+static int i3cdev_notifier_call(struct notifier_block *nb,
+				unsigned long action,
+				void *data)
+{
+	struct device *dev = data;
+
+	switch (action) {
+	case BUS_NOTIFY_ADD_DEVICE:
+	case BUS_NOTIFY_UNBOUND_DRIVER:
+		return i3cdev_attach(dev, NULL);
+	case BUS_NOTIFY_DEL_DEVICE:
+	case BUS_NOTIFY_BOUND_DRIVER:
+		return i3cdev_detach(dev, NULL);
+	}
+
+	return 0;
+}
+
+static struct notifier_block i3c_notifier = {
+	.notifier_call = i3cdev_notifier_call,
+};
+
+static int __init i3cdev_init(void)
+{
+	int res;
+
+	/* Dynamically request unused major number */
+	res = alloc_chrdev_region(&i3cdev_number, 0, I3C_MINORS, "i3c");
+	if (res)
+		goto out;
+
+	/* Create a classe to populate sysfs entries*/
+	i3cdev_class = class_create(THIS_MODULE, "i3cdev");
+	if (IS_ERR(i3cdev_class)) {
+		res = PTR_ERR(i3cdev_class);
+		goto out_unreg_chrdev;
+	}
+
+	/* Keep track of busses which have devices to add or remove later */
+	res = bus_register_notifier(&i3c_bus_type, &i3c_notifier);
+	if (res)
+		goto out_unreg_class;
+
+	/* Bind to already existing device without driver right away */
+	i3c_for_each_dev(NULL, i3cdev_attach);
+
+	return 0;
+
+out_unreg_class:
+	class_destroy(i3cdev_class);
+out_unreg_chrdev:
+	unregister_chrdev_region(i3cdev_number, I3C_MINORS);
+out:
+	pr_err("%s: Driver Initialisation failed\n", __FILE__);
+	return res;
+}
+
+static void __exit i3cdev_exit(void)
+{
+	bus_unregister_notifier(&i3c_bus_type, &i3c_notifier);
+	i3c_for_each_dev(NULL, i3cdev_detach);
+	class_destroy(i3cdev_class);
+	unregister_chrdev_region(i3cdev_number, I3C_MINORS);
+}
+
+MODULE_AUTHOR("Vitor Soares <soares@synopsys.com>");
+MODULE_DESCRIPTION("I3C /dev entries driver");
+MODULE_LICENSE("GPL");
+
+module_init(i3cdev_init);
+module_exit(i3cdev_exit);
diff --git a/drivers/i3c/internals.h b/drivers/i3c/internals.h
index 86b7b44cfca2..a6deedf5ce06 100644
--- a/drivers/i3c/internals.h
+++ b/drivers/i3c/internals.h
@@ -11,6 +11,7 @@
 #include <linux/i3c/master.h>
 
 extern struct bus_type i3c_bus_type;
+extern const struct device_type i3c_masterdev_type;
 
 void i3c_bus_normaluse_lock(struct i3c_bus *bus);
 void i3c_bus_normaluse_unlock(struct i3c_bus *bus);
@@ -23,4 +24,5 @@ int i3c_dev_enable_ibi_locked(struct i3c_dev_desc *dev);
 int i3c_dev_request_ibi_locked(struct i3c_dev_desc *dev,
 			       const struct i3c_ibi_setup *req);
 void i3c_dev_free_ibi_locked(struct i3c_dev_desc *dev);
+int i3c_for_each_dev(void *data, int (*fn)(struct device *, void *));
 #endif /* I3C_INTERNAL_H */
diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index c3b4c677b442..c0e88b8ded78 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -339,6 +339,7 @@ struct bus_type i3c_bus_type = {
 	.probe = i3c_device_probe,
 	.remove = i3c_device_remove,
 };
+EXPORT_SYMBOL_GPL(i3c_bus_type);
 
 static enum i3c_addr_slot_status
 i3c_bus_get_addr_slot_status(struct i3c_bus *bus, u16 addr)
@@ -541,9 +542,10 @@ static void i3c_masterdev_release(struct device *dev)
 	of_node_put(dev->of_node);
 }
 
-static const struct device_type i3c_masterdev_type = {
+const struct device_type i3c_masterdev_type = {
 	.groups	= i3c_masterdev_groups,
 };
+EXPORT_SYMBOL_GPL(i3c_masterdev_type);
 
 static int i3c_bus_set_mode(struct i3c_bus *i3cbus, enum i3c_bus_mode mode,
 			    unsigned long max_i2c_scl_rate)
@@ -1669,6 +1671,7 @@ static int i3c_master_bus_init(struct i3c_master_controller *master)
 	enum i3c_addr_slot_status status;
 	struct i2c_dev_boardinfo *i2cboardinfo;
 	struct i3c_dev_boardinfo *i3cboardinfo;
+	struct i3c_dev_desc *i3cdev, *i3ctmp;
 	struct i2c_dev_desc *i2cdev;
 	int ret;
 
@@ -2694,6 +2697,18 @@ void i3c_dev_free_ibi_locked(struct i3c_dev_desc *dev)
 	dev->ibi = NULL;
 }
 
+int i3c_for_each_dev(void *data, int (*fn)(struct device *, void *))
+{
+	int res;
+
+	mutex_lock(&i3c_core_lock);
+	res = bus_for_each_dev(&i3c_bus_type, NULL, data, fn);
+	mutex_unlock(&i3c_core_lock);
+
+	return res;
+}
+EXPORT_SYMBOL_GPL(i3c_for_each_dev);
+
 static int __init i3c_init(void)
 {
 	return bus_register(&i3c_bus_type);
diff --git a/drivers/i3c/master/Kconfig b/drivers/i3c/master/Kconfig
index 3b8f95916f46..a362b3d216e3 100644
--- a/drivers/i3c/master/Kconfig
+++ b/drivers/i3c/master/Kconfig
@@ -43,3 +43,8 @@ config MIPI_I3C_HCI
 
 	  This driver can also be built as a module.  If so, the module will be
 	  called mipi-i3c-hci.
+
+config ASPEED_I3C_GLOBAL
+       tristate "ASPEED I3C global driver"
+       depends on I3C
+       depends on MACH_ASPEED_G6
diff --git a/drivers/i3c/master/Makefile b/drivers/i3c/master/Makefile
index b3fee0f690b2..f7d0b94b768b 100644
--- a/drivers/i3c/master/Makefile
+++ b/drivers/i3c/master/Makefile
@@ -1,4 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_ASPEED_I3C_GLOBAL)		+= aspeed-i3c-global.o
 obj-$(CONFIG_CDNS_I3C_MASTER)		+= i3c-master-cdns.o
 obj-$(CONFIG_DW_I3C_MASTER)		+= dw-i3c-master.o
 obj-$(CONFIG_SVC_I3C_MASTER)		+= svc-i3c-master.o
diff --git a/drivers/i3c/master/aspeed-i3c-global.c b/drivers/i3c/master/aspeed-i3c-global.c
new file mode 100644
index 000000000000..0283a3d7977f
--- /dev/null
+++ b/drivers/i3c/master/aspeed-i3c-global.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2019 ASPEED Technology Inc.
+
+#include <linux/clk.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/io.h>
+#include <linux/reset.h>
+#include <linux/delay.h>
+
+#define ASPEED_I3CG_CTRL(x)		(0x10 + (x*0x10))
+#define ASPEED_I3CG_SET(x)		(0x14 + (x*0x10))
+
+struct aspeed_i3c_global {
+	void __iomem		*base;
+	struct reset_control	*rst;
+};
+
+static int aspeed_i3c_global_probe(struct platform_device *pdev)
+{
+	struct aspeed_i3c_global *i3c_global;
+	struct device_node *node = pdev->dev.of_node;
+	int i = 0;
+
+	i3c_global = kzalloc(sizeof(*i3c_global), GFP_KERNEL);
+	if (!i3c_global)
+		return -ENOMEM;
+
+	i3c_global->base = of_iomap(node, 0);
+	if (!i3c_global->base) {
+		return -ENOMEM;
+	}
+
+	i3c_global->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+
+	if (IS_ERR(i3c_global->rst)) {
+		if (PTR_ERR(i3c_global->rst) != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "missing or invalid reset controller device tree entry\n");
+		return PTR_ERR(i3c_global->rst);
+	}
+
+	reset_control_assert(i3c_global->rst);
+	udelay(3);
+	reset_control_deassert(i3c_global->rst);
+
+	/* init */
+	for(i = 0; i < 5; i++)
+		writel(0x000474c4, i3c_global->base + ASPEED_I3CG_SET(i));
+
+	return 0;
+}
+
+static const struct of_device_id aspeed_i3c_of_match[] = {
+	{ .compatible = "aspeed,ast2600-i3c-global", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, aspeed_i3c_of_match);
+
+static struct platform_driver aspeed_i3c_driver = {
+	.probe  = aspeed_i3c_global_probe,
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.of_match_table = aspeed_i3c_of_match,
+	},
+};
+module_platform_driver(aspeed_i3c_driver);
+
+MODULE_AUTHOR("Ryan Chen");
+MODULE_DESCRIPTION("ASPEED I3C Global Driver");
+MODULE_LICENSE("GPL v2");