by Johannes Thumshirn

[permalink] [raw]

Subject: [PATCH v2 1/3] drivers: Introduce MEN Chameleon Bus

The MCB (MEN Chameleon Bus) is a Bus specific to MEN Mikroelektronik
FPGA based devices. It is used to identify MCB based IP-Cores within
an FPGA and provide the necessary framework for instantiating drivers
for these devices.

Signed-off-by: Johannes Thumshirn <[email protected]>
---
MAINTAINERS | 6 +
drivers/Kconfig | 2 +
drivers/Makefile | 1 +
drivers/mcb/Kconfig | 15 ++
drivers/mcb/Makefile | 5 +
drivers/mcb/mcb-core.c | 414 ++++++++++++++++++++++++++++++++++++++++
drivers/mcb/mcb-internal.h | 116 +++++++++++
drivers/mcb/mcb-parse.c | 159 +++++++++++++++
include/linux/mcb.h | 119 ++++++++++++
include/linux/mod_devicetable.h | 5 +
10 files changed, 842 insertions(+)
create mode 100644 drivers/mcb/Kconfig
create mode 100644 drivers/mcb/Makefile
create mode 100644 drivers/mcb/mcb-core.c
create mode 100644 drivers/mcb/mcb-internal.h
create mode 100644 drivers/mcb/mcb-parse.c
create mode 100644 include/linux/mcb.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 5aa1c50..68a3cad 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5666,6 +5666,12 @@ L: [email protected]
S: Supported
F: drivers/watchdog/mena21_wdt.c

+MEN CHAMELEON BUS (mcb)
+M: Johannes Thumshirn <[email protected]>
+S: Supported
+F: drivers/mcb/
+F: include/linux/mcb.h
+
METAG ARCHITECTURE
M: James Hogan <[email protected]>
L: [email protected]
diff --git a/drivers/Kconfig b/drivers/Kconfig
index b3138fb..df2ac52 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -170,4 +170,6 @@ source "drivers/phy/Kconfig"

source "drivers/powercap/Kconfig"

+source "drivers/mcb/Kconfig"
+
endmenu
diff --git a/drivers/Makefile b/drivers/Makefile
index 8e3b8b0..c5bf50c 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -155,3 +155,4 @@ obj-$(CONFIG_IPACK_BUS) += ipack/
obj-$(CONFIG_NTB) += ntb/
obj-$(CONFIG_FMC) += fmc/
obj-$(CONFIG_POWERCAP) += powercap/
+obj-$(CONFIG_MCB) += mcb/
diff --git a/drivers/mcb/Kconfig b/drivers/mcb/Kconfig
new file mode 100644
index 0000000..44c82d6
--- /dev/null
+++ b/drivers/mcb/Kconfig
@@ -0,0 +1,15 @@
+#
+# MEN Chameleon Bus (MCB) support
+#
+
+menuconfig MCB
+ tristate "MCB support"
+ default m
+ help
+
+ The MCB (MEN Chameleon Bus) is a Bus specific to MEN Mikroelektronik
+ FPGA based devices. It is used to identify MCB based IP-Cores within
+ an FPGA and provide the necessary framework for instantiating drivers
+ for these devices.
+
+ If build as a module, the module is called mcb.ko
diff --git a/drivers/mcb/Makefile b/drivers/mcb/Makefile
new file mode 100644
index 0000000..2d9a751
--- /dev/null
+++ b/drivers/mcb/Makefile
@@ -0,0 +1,5 @@
+
+obj-$(CONFIG_MCB) += mcb.o
+
+mcb-y += mcb-core.o
+mcb-y += mcb-parse.o
diff --git a/drivers/mcb/mcb-core.c b/drivers/mcb/mcb-core.c
new file mode 100644
index 0000000..bbe1293
--- /dev/null
+++ b/drivers/mcb/mcb-core.c
@@ -0,0 +1,414 @@
+/*
+ * MEN Chameleon Bus.
+ *
+ * Copyright (C) 2013 MEN Mikroelektronik GmbH (http://www.men.de)
+ * Author: Johannes Thumshirn <[email protected]>
+ *
+ * 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.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/idr.h>
+#include <linux/mcb.h>
+
+static DEFINE_IDA(mcb_ida);
+
+static const struct mcb_device_id *mcb_match_id(const struct mcb_device_id *ids,
+ struct mcb_device *dev)
+{
+ if (ids) {
+ while (ids->device) {
+ if (ids->device == dev->id)
+ return ids;
+ ids++;
+ }
+ }
+
+ return NULL;
+}
+
+static int mcb_match(struct device *dev, struct device_driver *drv)
+{
+ struct mcb_driver *mdrv = to_mcb_driver(drv);
+ struct mcb_device *mdev = to_mcb_device(dev);
+ const struct mcb_device_id *found_id;
+
+ found_id = mcb_match_id(mdrv->id_table, mdev);
+ if (found_id)
+ return 1;
+
+ return 0;
+}
+
+static int mcb_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+ struct mcb_device *mdev = to_mcb_device(dev);
+ int ret;
+
+ ret = add_uevent_var(env, "MODALIAS=mcb:16z%03d", mdev->id);
+ if (ret)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static int mcb_probe(struct device *dev)
+{
+ struct mcb_driver *mdrv = to_mcb_driver(dev->driver);
+ struct mcb_device *mdev = to_mcb_device(dev);
+ const struct mcb_device_id *found_id;
+
+ found_id = mcb_match_id(mdrv->id_table, mdev);
+ if (!found_id)
+ return -ENODEV;
+
+ return mdrv->probe(mdev, found_id);
+}
+
+static int mcb_remove(struct device *dev)
+{
+ struct mcb_driver *mdrv = to_mcb_driver(dev->driver);
+ struct mcb_device *mdev = to_mcb_device(dev);
+
+ mdrv->remove(mdev);
+
+ put_device(&mdev->dev);
+
+ return 0;
+}
+
+static void mcb_shutdown(struct device *dev)
+{
+ struct mcb_device *mdev = to_mcb_device(dev);
+ struct mcb_driver *mdrv = mdev->driver;
+
+ if (mdrv && mdrv->shutdown)
+ mdrv->shutdown(mdev);
+}
+
+static struct bus_type mcb_bus_type = {
+ .name = "mcb",
+ .match = mcb_match,
+ .uevent = mcb_uevent,
+ .probe = mcb_probe,
+ .remove = mcb_remove,
+ .shutdown = mcb_shutdown,
+};
+
+/**
+ * __mcb_register_driver() - Register a @mcb_driver at the system
+ * @drv: The @mcb_driver
+ * @owner: The @mcb_driver's module
+ * @mod_name: The name of the @mcb_driver's module
+ *
+ * Register a @mcb_driver at the system. Perform some sanity checks, if
+ * the .probe and .remove methods are provided by the driver.
+ */
+int __mcb_register_driver(struct mcb_driver *drv, struct module *owner,
+ const char *mod_name)
+{
+ if (!drv->probe || !drv->remove)
+ return -EINVAL;
+
+ drv->driver.owner = owner;
+ drv->driver.bus = &mcb_bus_type;
+ drv->driver.mod_name = mod_name;
+
+ return driver_register(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(__mcb_register_driver);
+
+/**
+ * mcb_unregister_driver() - Unregister a @mcb_driver from the system
+ * @drv: The @mcb_driver
+ *
+ * Unregister a @mcb_driver from the system.
+ */
+void mcb_unregister_driver(struct mcb_driver *drv)
+{
+ driver_unregister(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(mcb_unregister_driver);
+
+static void mcb_release_dev(struct device *dev)
+{
+ struct mcb_device *mdev = to_mcb_device(dev);
+
+ mcb_bus_put(mdev->bus);
+ kfree(mdev);
+}
+
+/**
+ * mcb_device_register() - Register a mcb_device
+ * @bus: The @mcb_bus of the device
+ * @dev: The @mcb_device
+ *
+ * Register a specific @mcb_device at a @mcb_bus and the system itself.
+ */
+int mcb_device_register(struct mcb_bus *bus, struct mcb_device *dev)
+{
+ int ret;
+ int device_id;
+
+ device_initialize(&dev->dev);
+ dev->dev.bus = &mcb_bus_type;
+ dev->dev.parent = bus->dev.parent;
+ dev->dev.release = mcb_release_dev;
+
+ device_id = dev->id;
+ dev_set_name(&dev->dev, "mcb%d-16z%03d-%d:%d:%d",
+ bus->bus_nr, device_id, dev->inst, dev->group, dev->var);
+
+ ret = device_add(&dev->dev);
+ if (ret < 0) {
+ pr_err("Failed registering device 16z%03d on bus mcb%d (%d)\n",
+ device_id, bus->bus_nr, ret);
+ goto out;
+ }
+
+ return 0;
+
+out:
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(mcb_device_register);
+
+/**
+ * mcb_alloc_bus() - Allocate a new @mcb_bus
+ *
+ * Allocate a new @mcb_bus.
+ */
+struct mcb_bus *mcb_alloc_bus(void)
+{
+ struct mcb_bus *bus;
+ int bus_nr;
+
+ bus = kzalloc(sizeof(struct mcb_bus), GFP_KERNEL);
+ if (!bus)
+ return NULL;
+
+ bus_nr = ida_simple_get(&mcb_ida, 0, 0, GFP_KERNEL);
+ if (bus_nr < 0) {
+ kfree(bus);
+ return ERR_PTR(bus_nr);
+ }
+
+ INIT_LIST_HEAD(&bus->children);
+ bus->bus_nr = bus_nr;
+
+ return bus;
+}
+EXPORT_SYMBOL_GPL(mcb_alloc_bus);
+
+static int __mcb_devices_unregister(struct device *dev, void *data)
+{
+ device_unregister(dev);
+ return 0;
+}
+
+static void mcb_devices_unregister(struct mcb_bus *bus)
+{
+ bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_devices_unregister);
+}
+/**
+ * mcb_release_bus() - Free a @mcb_bus
+ * @bus: The @mcb_bus to release
+ *
+ * Release an allocated @mcb_bus from the system.
+ */
+void mcb_release_bus(struct mcb_bus *bus)
+{
+ mcb_devices_unregister(bus);
+
+ ida_simple_remove(&mcb_ida, bus->bus_nr);
+
+ kfree(bus);
+}
+EXPORT_SYMBOL_GPL(mcb_release_bus);
+
+/**
+ * mcb_bus_put() - Increment refcnt
+ * @bus: The @mcb_bus
+ *
+ * Get a @mcb_bus' ref
+ */
+struct mcb_bus *mcb_bus_get(struct mcb_bus *bus)
+{
+ if (bus)
+ get_device(&bus->dev);
+
+ return bus;
+}
+EXPORT_SYMBOL_GPL(mcb_bus_get);
+
+/**
+ * mcb_bus_put() - Decrement refcnt
+ * @bus: The @mcb_bus
+ *
+ * Release a @mcb_bus' ref
+ */
+void mcb_bus_put(struct mcb_bus *bus)
+{
+ if (bus)
+ put_device(&bus->dev);
+}
+EXPORT_SYMBOL_GPL(mcb_bus_put);
+
+/**
+ * mcb_alloc_dev() - Allocate a device
+ * @bus: The @mcb_bus the device is part of
+ *
+ * Allocate a @mcb_device and add bus.
+ */
+struct mcb_device *mcb_alloc_dev(struct mcb_bus *bus)
+{
+ struct mcb_device *dev;
+
+ dev = kzalloc(sizeof(struct mcb_device), GFP_KERNEL);
+ if (!dev)
+ return NULL;
+
+ INIT_LIST_HEAD(&dev->bus_list);
+ dev->bus = bus;
+
+ return dev;
+}
+EXPORT_SYMBOL_GPL(mcb_alloc_dev);
+
+/**
+ * mcb_free_dev() - Free @mcb_device
+ * @dev: The device to free
+ *
+ * Free a @mcb_device
+ */
+void mcb_free_dev(struct mcb_device *dev)
+{
+ kfree(dev);
+}
+EXPORT_SYMBOL_GPL(mcb_free_dev);
+
+static int __mcb_bus_add_devices(struct device *dev, void *data)
+{
+ struct mcb_device *mdev = to_mcb_device(dev);
+ int retval;
+
+ if (mdev->is_added)
+ return 0;
+
+ retval = device_attach(dev);
+ if (retval < 0)
+ dev_err(dev, "Error adding device (%d)\n", retval);
+
+ mdev->is_added = true;
+
+ return 0;
+}
+
+static int __mcb_bus_add_child(struct device *dev, void *data)
+{
+ struct mcb_device *mdev = to_mcb_device(dev);
+ struct mcb_bus *child;
+
+ BUG_ON(!mdev->is_added);
+ child = mdev->subordinate;
+
+ if (child)
+ mcb_bus_add_devices(child);
+
+ return 0;
+}
+
+/**
+ * mcb_bus_add_devices() - Add devices in the bus' internal device list
+ * @bus: The @mcb_bus we add the devices
+ *
+ * Add devices in the bus' internal device list to the system.
+ */
+void mcb_bus_add_devices(const struct mcb_bus *bus)
+{
+ bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_bus_add_devices);
+ bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_bus_add_child);
+
+}
+EXPORT_SYMBOL_GPL(mcb_bus_add_devices);
+
+/**
+ * mcb_request_mem() - Request memory
+ * @dev: The @mcb_device the memory is for
+ * @name: The name for the memory reference.
+ *
+ * Request memory for a @mcb_device. If @name is NULL the driver name will
+ * be used.
+ */
+struct resource *mcb_request_mem(struct mcb_device *dev, const char *name)
+{
+ struct resource *mem;
+ u32 size;
+
+ if (!name)
+ name = dev->dev.driver->name;
+
+ size = resource_size(&dev->mem);
+
+ mem = request_mem_region(dev->mem.start, size, name);
+ if (!mem)
+ return ERR_PTR(-EBUSY);
+
+ return mem;
+}
+EXPORT_SYMBOL_GPL(mcb_request_mem);
+
+/**
+ * mcb_release_mem() - Release memory requested by device
+ * @dev: The @mcb_device that requested the memory
+ *
+ * Release memory that was prior requested via @mcb_request_mem().
+ */
+void mcb_release_mem(struct resource *mem)
+{
+ u32 size;
+
+ size = resource_size(mem);
+ release_mem_region(mem->start, size);
+}
+EXPORT_SYMBOL_GPL(mcb_release_mem);
+
+/**
+ * mcb_get_irq() - Get device's IRQ number
+ * @dev: The @mcb_device the IRQ is for
+ *
+ * Get the IRQ number of a given @mcb_device.
+ */
+int mcb_get_irq(struct mcb_device *dev)
+{
+ struct resource *irq = &dev->irq;
+
+ return irq->start;
+}
+EXPORT_SYMBOL_GPL(mcb_get_irq);
+
+static int mcb_init(void)
+{
+ return bus_register(&mcb_bus_type);
+}
+
+static void mcb_exit(void)
+{
+ bus_unregister(&mcb_bus_type);
+}
+
+/* mcb must be initialized after PCI but before the chameleon drivers.
+ * That means we must use some initcall between subsys_initcall and
+ * device_initcall.
+ */
+fs_initcall(mcb_init);
+module_exit(mcb_exit);
+
+MODULE_DESCRIPTION("MEN Chameleon Bus Driver");
+MODULE_AUTHOR("Johannes Thumshirn <[email protected]>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mcb/mcb-internal.h b/drivers/mcb/mcb-internal.h
new file mode 100644
index 0000000..db22777
--- /dev/null
+++ b/drivers/mcb/mcb-internal.h
@@ -0,0 +1,116 @@
+#ifndef __MCB_INTERNAL
+#define __MCB_INTERNAL
+
+#include <linux/types.h>
+
+#define CHAMELEON_FILENAME_LEN 12
+#define CHAMELEONV2_MAGIC 0xabce
+
+enum chameleon_descriptor_type {
+ CHAMELEON_DTYPE_GENERAL = 0x0,
+ CHAMELEON_DTYPE_BRIDGE = 0x1,
+ CHAMELEON_DTYPE_CPU = 0x2,
+ CHAMELEON_DTYPE_BAR = 0x3,
+ CHAMELEON_DTYPE_END = 0xf,
+};
+
+enum chameleon_bus_type {
+ CHAMELEON_BUS_WISHBONE,
+ CHAMELEON_BUS_AVALON,
+ CHAMELEON_BUS_LPC,
+ CHAMELEON_BUS_ISA,
+};
+
+/**
+ * struct chameleon_fpga_header
+ *
+ * @revision: Revison of Chameleon table in FPGA
+ * @model: Chameleon table model ASCII char
+ * @minor: Revision minor
+ * @bus_type: Bus type (usually %CHAMELEON_BUS_WISHBONE)
+ * @magic: Chameleon header magic number (0xabce for version 2)
+ * @reserved: Reserved
+ * @filename: Filename of FPGA bitstream
+ */
+struct chameleon_fpga_header {
+ u8 revision;
+ char model;
+ u8 minor;
+ u8 bus_type;
+ u16 magic;
+ u16 reserved;
+ /* This one has no '\0' at the end!!! */
+ char filename[CHAMELEON_FILENAME_LEN];
+} __packed;
+#define HEADER_MAGIC_OFFSET 0x4
+
+/**
+ * struct chameleon_gdd - Chameleon General Device Descriptor
+ *
+ * @irq: the position in the FPGA's IRQ controller vector
+ * @rev: the revision of the variant's implementation
+ * @var: the variant of the IP core
+ * @dev: the device the IP core is
+ * @dtype: device descriptor type
+ * @bar: BAR offset that must be added to module offset
+ * @inst: the instance number of the device, 0 is first instance
+ * @group: the group the device belongs to (0 = no group)
+ * @reserved: reserved
+ * @offset: beginning of the address window of desired module
+ * @size: size of the module's address window
+ */
+struct chameleon_gdd {
+ __le32 reg1;
+ __le32 reg2;
+ __le32 offset;
+ __le32 size;
+
+} __packed;
+
+/* GDD Register 1 fields */
+#define GDD_IRQ(x) ((x) & 0x1f)
+#define GDD_REV(x) (((x) >> 5) & 0x3f)
+#define GDD_VAR(x) (((x) >> 11) & 0x3f)
+#define GDD_DEV(x) (((x) >> 18) & 0x3ff)
+#define GDD_DTY(x) (((x) >> 28) & 0xf)
+
+/* GDD Register 2 fields */
+#define GDD_BAR(x) ((x) & 0x7)
+#define GDD_INS(x) (((x) >> 3) & 0x3f)
+#define GDD_GRP(x) (((x) >> 9) & 0x3f)
+
+/**
+ * struct chameleon_bdd - Chameleon Bridge Device Descriptor
+ *
+ * @irq: the position in the FPGA's IRQ controller vector
+ * @rev: the revision of the variant's implementation
+ * @var: the variant of the IP core
+ * @dev: the device the IP core is
+ * @dtype: device descriptor type
+ * @bar: BAR offset that must be added to module offset
+ * @inst: the instance number of the device, 0 is first instance
+ * @dbar: destination bar from the bus _behind_ the bridge
+ * @chamoff: offset within the BAR of the source bus
+ * @offset:
+ * @size:
+ */
+struct chameleon_bdd {
+ unsigned int irq:6;
+ unsigned int rev:6;
+ unsigned int var:6;
+ unsigned int dev:10;
+ unsigned int dtype:4;
+ unsigned int bar:3;
+ unsigned int inst:6;
+ unsigned int dbar:3;
+ unsigned int group:6;
+ unsigned int reserved:14;
+ u32 chamoff;
+ u32 offset;
+ u32 size;
+} __packed;
+
+int chameleon_parse_cells(struct mcb_bus *bus, phys_addr_t mapbase,
+ void __iomem *base);
+
+#endif
diff --git a/drivers/mcb/mcb-parse.c b/drivers/mcb/mcb-parse.c
new file mode 100644
index 0000000..d1278b5
--- /dev/null
+++ b/drivers/mcb/mcb-parse.c
@@ -0,0 +1,159 @@
+#include <linux/types.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/io.h>
+#include <linux/mcb.h>
+
+#include "mcb-internal.h"
+
+struct mcb_parse_priv {
+ phys_addr_t mapbase;
+ void __iomem *base;
+};
+
+#define for_each_chameleon_cell(dtype, p) \
+ for ((dtype) = get_next_dtype((p)); \
+ (dtype) != CHAMELEON_DTYPE_END; \
+ (dtype) = get_next_dtype((p)))
+
+static inline uint32_t get_next_dtype(void __iomem *p)
+{
+ uint32_t dtype;
+
+ dtype = readl(p);
+ return dtype >> 28;
+}
+
+static int chameleon_parse_bdd(struct mcb_bus *bus,
+ phys_addr_t mapbase,
+ void __iomem *base)
+{
+ return 0;
+}
+
+static int chameleon_parse_gdd(struct mcb_bus *bus,
+ phys_addr_t mapbase,
+ void __iomem *base)
+{
+ struct chameleon_gdd __iomem *gdd =
+ (struct chameleon_gdd __iomem *) base;
+ struct mcb_device *mdev;
+ u32 offset;
+ u32 size;
+ int ret;
+ __le32 reg1;
+ __le32 reg2;
+
+ mdev = mcb_alloc_dev(bus);
+ if (!mdev)
+ return -ENOMEM;
+
+ reg1 = readl(&gdd->reg1);
+ reg2 = readl(&gdd->reg2);
+ offset = readl(&gdd->offset);
+ size = readl(&gdd->size);
+
+ mdev->id = GDD_DEV(reg1);
+ mdev->rev = GDD_REV(reg1);
+ mdev->var = GDD_VAR(reg1);
+ mdev->bar = GDD_BAR(reg1);
+ mdev->group = GDD_GRP(reg2);
+ mdev->inst = GDD_INS(reg2);
+
+ pr_debug("Found a 16z%03d\n", mdev->id);
+
+ mdev->irq.start = GDD_IRQ(reg1);
+ mdev->irq.end = GDD_IRQ(reg1);
+ mdev->irq.flags = IORESOURCE_IRQ;
+
+ mdev->mem.start = mapbase + offset;
+ mdev->mem.end = mdev->mem.start + size - 1;
+ mdev->mem.flags = IORESOURCE_MEM;
+
+ mdev->is_added = false;
+
+ ret = mcb_device_register(bus, mdev);
+ if (ret < 0)
+ goto err;
+
+ return 0;
+
+err:
+ mcb_free_dev(mdev);
+
+ return ret;
+}
+
+int chameleon_parse_cells(struct mcb_bus *bus, phys_addr_t mapbase,
+ void __iomem *base)
+{
+ char __iomem *p = base;
+ struct chameleon_fpga_header *header;
+ uint32_t dtype;
+ int num_cells = 0;
+ int ret = 0;
+ u32 hsize;
+
+ hsize = sizeof(struct chameleon_fpga_header);
+
+ header = kzalloc(hsize, GFP_KERNEL);
+ if (!header)
+ return -ENOMEM;
+
+ /* Extract header information */
+ memcpy_fromio(header, p, hsize);
+ /* We only support chameleon v2 at the moment */
+ header->magic = le16_to_cpu(header->magic);
+ if (header->magic != CHAMELEONV2_MAGIC) {
+ pr_err("Unsupported chameleon version 0x%x\n",
+ header->magic);
+ kfree(header);
+ return -ENODEV;
+ }
+ p += hsize;
+
+ pr_debug("header->revision = %d\n", header->revision);
+ pr_debug("header->model = 0x%x ('%c')\n", header->model,
+ header->model);
+ pr_debug("header->minor = %d\n", header->minor);
+ pr_debug("header->bus_type = 0x%x\n", header->bus_type);
+
+
+ pr_debug("header->magic = 0x%x\n", header->magic);
+ pr_debug("header->filename = \"%.*s\"\n", CHAMELEON_FILENAME_LEN,
+ header->filename);
+
+ for_each_chameleon_cell(dtype, p) {
+ switch (dtype) {
+ case CHAMELEON_DTYPE_GENERAL:
+ ret = chameleon_parse_gdd(bus, mapbase, p);
+ if (ret < 0)
+ goto out;
+ p += sizeof(struct chameleon_gdd);
+ break;
+ case CHAMELEON_DTYPE_BRIDGE:
+ chameleon_parse_bdd(bus, mapbase, p);
+ p += sizeof(struct chameleon_bdd);
+ break;
+ case CHAMELEON_DTYPE_END:
+ break;
+ default:
+ pr_err("Invalid chameleon descriptor type 0x%x\n",
+ dtype);
+ return -EINVAL;
+ }
+ num_cells++;
+ }
+
+ if (num_cells == 0)
+ num_cells = -EINVAL;
+
+ kfree(header);
+ return num_cells;
+
+out:
+ kfree(header);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(chameleon_parse_cells);
diff --git a/include/linux/mcb.h b/include/linux/mcb.h
new file mode 100644
index 0000000..2db284d
--- /dev/null
+++ b/include/linux/mcb.h
@@ -0,0 +1,119 @@
+/*
+ * MEN Chameleon Bus.
+ *
+ * Copyright (C) 2014 MEN Mikroelektronik GmbH (http://www.men.de)
+ * Author: Johannes Thumshirn <[email protected]>
+ *
+ * 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.
+ */
+#ifndef _LINUX_MCB_H
+#define _LINUX_MCB_H
+
+#include <linux/mod_devicetable.h>
+#include <linux/device.h>
+#include <linux/irqreturn.h>
+
+struct mcb_driver;
+
+/**
+ * struct mcb_bus - MEN Chameleon Bus
+ *
+ * @dev: pointer to carrier device
+ * @children: the child busses
+ * @bus_nr: mcb bus number
+ */
+struct mcb_bus {
+ struct list_head children;
+ struct device dev;
+ int bus_nr;
+};
+#define to_mcb_bus(b) container_of((b), struct mcb_bus, dev)
+
+/**
+ * struct mcb_device - MEN Chameleon Bus device
+ *
+ * @bus_list: internal list handling for bus code
+ * @dev: device in kernel representation
+ * @bus: mcb bus the device is plugged to
+ * @subordinate: subordinate MCBus in case of bridge
+ * @is_added: flag to check if device is added to bus
+ * @driver: associated mcb_driver
+ * @id: mcb device id
+ * @inst: instance in Chameleon table
+ * @group: group in Chameleon table
+ * @var: variant in Chameleon table
+ * @bar: BAR in Chameleon table
+ * @rev: revision in Chameleon table
+ * @irq: IRQ resource
+ * @memory: memory resource
+ */
+struct mcb_device {
+ struct list_head bus_list;
+ struct device dev;
+ struct mcb_bus *bus;
+ struct mcb_bus *subordinate;
+ bool is_added;
+ struct mcb_driver *driver;
+ u16 id;
+ int inst;
+ int group;
+ int var;
+ int bar;
+ int rev;
+ struct resource irq;
+ struct resource mem;
+};
+#define to_mcb_device(x) container_of((x), struct mcb_device, dev)
+
+/**
+ * struct mcb_driver - MEN Chameleon Bus device driver
+ *
+ * @driver: device_driver
+ * @id_table: mcb id table
+ * @probe: probe callback
+ * @remove: remove callback
+ * @shutdown: shutdown callback
+ */
+struct mcb_driver {
+ struct device_driver driver;
+ const struct mcb_device_id *id_table;
+ int (*probe)(struct mcb_device *mdev, const struct mcb_device_id *id);
+ void (*remove)(struct mcb_device *mdev);
+ void (*shutdown)(struct mcb_device *mdev);
+};
+#define to_mcb_driver(x) container_of((x), struct mcb_driver, driver)
+
+static inline void *mcb_get_drvdata(struct mcb_device *dev)
+{
+ return dev_get_drvdata(&dev->dev);
+}
+
+static inline void mcb_set_drvdata(struct mcb_device *dev, void *data)
+{
+ dev_set_drvdata(&dev->dev, data);
+}
+
+extern int __must_check __mcb_register_driver(struct mcb_driver *drv,
+ struct module *owner,
+ const char *mod_name);
+#define mcb_register_driver(driver) \
+ __mcb_register_driver(driver, THIS_MODULE, KBUILD_MODNAME)
+extern void mcb_unregister_driver(struct mcb_driver *driver);
+#define module_mcb_driver(__mcb_driver) \
+ module_driver(__mcb_driver, mcb_register_driver, mcb_unregister_driver);
+extern void mcb_bus_add_devices(const struct mcb_bus *bus);
+extern int mcb_device_register(struct mcb_bus *bus, struct mcb_device *dev);
+extern struct mcb_bus *mcb_alloc_bus(void);
+extern struct mcb_bus *mcb_bus_get(struct mcb_bus *bus);
+extern void mcb_bus_put(struct mcb_bus *bus);
+extern struct mcb_device *mcb_alloc_dev(struct mcb_bus *bus);
+extern void mcb_free_dev(struct mcb_device *dev);
+extern void mcb_release_bus(struct mcb_bus *bus);
+extern struct resource *mcb_request_mem(struct mcb_device *dev,
+ const char *name);
+extern void mcb_release_mem(struct resource *mem);
+extern int mcb_get_irq(struct mcb_device *dev);
+
+#endif /* _LINUX_MCB_H */
diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index 45e9214..262cb85 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -599,4 +599,9 @@ struct rio_device_id {
__u16 asm_did, asm_vid;
};

+struct mcb_device_id {
+ __u16 device;
+ kernel_ulong_t driver_data;
+};
+
#endif /* LINUX_MOD_DEVICETABLE_H */
--
1.8.5.3

2014-02-25 20:41:39

by Jonathan Cameron

[permalink] [raw]

Subject: Re: [PATCH v2 3/3] iio: adc: Add MEN 16z188 ADC driver

On 24/02/14 17:16, Johannes Thumshirn wrote:
> Add support for MEN 16z188 ADC IP Core on MCB FPGAs.
>
> Signed-off-by: Johannes Thumshirn <[email protected]>
Looks good. One possible issue with devm usage. It looks like
userspace interfaces will get removed after some other bits that
they will rely on. I missed this the first time around.
> ---
> drivers/iio/adc/Kconfig | 10 +++
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/men_z188_adc.c | 170 +++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 181 insertions(+)
> create mode 100644 drivers/iio/adc/men_z188_adc.c
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 2209f28..5c63f091 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -155,6 +155,16 @@ config MCP3422
> This driver can also be built as a module. If so, the module will be
> called mcp3422.
>
> +config MEN_Z188_ADC
> + tristate "MEN 16z188 ADC IP Core support"
> + depends on MCB
> + help
> + Say yes here to enable support for the MEN 16z188 ADC IP-Core on a MCB
> + carrier.
> +
> + This driver can also be built as a module. If so, the module will be
> + called men_z188_adc.
> +
> config NAU7802
> tristate "Nuvoton NAU7802 ADC driver"
> depends on I2C
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index ba9a10a..85a4a04 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -17,6 +17,7 @@ obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
> obj-$(CONFIG_MAX1363) += max1363.o
> obj-$(CONFIG_MCP320X) += mcp320x.o
> obj-$(CONFIG_MCP3422) += mcp3422.o
> +obj-$(CONFIG_MEN_Z188_ADC) += men_z188_adc.o
> obj-$(CONFIG_NAU7802) += nau7802.o
> obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
> obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o
> diff --git a/drivers/iio/adc/men_z188_adc.c b/drivers/iio/adc/men_z188_adc.c
> new file mode 100644
> index 0000000..da7f3d0
> --- /dev/null
> +++ b/drivers/iio/adc/men_z188_adc.c
> @@ -0,0 +1,170 @@
> +/*
> + * MEN 16z188 Analog to Digial Converter
> + *
> + * Copyright (C) 2014 MEN Mikroelektronik GmbH (http://www.men.de)
> + * Author: Johannes Thumshirn <[email protected]>
> + *
> + * 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.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mcb.h>
> +#include <linux/iio/iio.h>
> +
> +#define Z188_ADC_MAX_CHAN 8
> +#define Z188_ADC_GAIN 0x0700000
> +#define Z188_MODE_VOLTAGE BIT(27)
> +#define Z188_CFG_AUTO 0x1
> +#define Z188_CTRL_REG 0x40
> +
> +#define ADC_DATA(x) (((x) >> 2) & 0x7ffffc)
> +#define ADC_OVR(x) ((x) & 0x1)
> +
> +struct z188_adc {
> + struct resource *mem;
> + void __iomem *base;
> +};
> +
> +#define Z188_ADC_CHANNEL(idx) { \
> + .type = IIO_VOLTAGE, \
> + .indexed = 1, \
> + .channel = (idx), \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> +}
> +
> +static const struct iio_chan_spec z188_adc_iio_channels[] = {
> + Z188_ADC_CHANNEL(0),
> + Z188_ADC_CHANNEL(1),
> + Z188_ADC_CHANNEL(2),
> + Z188_ADC_CHANNEL(3),
> + Z188_ADC_CHANNEL(4),
> + Z188_ADC_CHANNEL(5),
> + Z188_ADC_CHANNEL(6),
> + Z188_ADC_CHANNEL(7),
> +};
> +
> +static int z188_iio_read_raw(struct iio_dev *iio_dev,
> + struct iio_chan_spec const *chan,
> + int *val,
> + int *val2,
> + long info)
> +{
> + struct z188_adc *adc = iio_priv(iio_dev);
> + int ret;
> + u16 tmp;
> +
> + switch (info) {
> + case IIO_CHAN_INFO_RAW:
> + tmp = readw(adc->base + chan->channel * 4);
> +
> + if (ADC_OVR(tmp)) {
> + dev_info(&iio_dev->dev,
> + "Oversampling error on ADC channel %d\n",
> + chan->channel);
> + return -EIO;
> + }
> + *val = ADC_DATA(tmp);
> + ret = IIO_VAL_INT;
> + break;
> + default:
> + ret = -EINVAL;
> + break;
> + }
> +
> + return ret;
> +}
> +
> +static struct iio_info z188_adc_info = {
> + .read_raw = &z188_iio_read_raw,
> + .driver_module = THIS_MODULE,
> +};
> +
> +static void men_z188_config_channels(void __iomem *addr)
> +{
> + int i;
> + u32 cfg;
> + u32 ctl;
> +
> + ctl = readl(addr + Z188_CTRL_REG);
> + ctl |= Z188_CFG_AUTO;
> + writel(ctl, addr + Z188_CTRL_REG);
> +
> + for (i = 0; i < Z188_ADC_MAX_CHAN; i++) {
> + cfg = readl(addr + i);
> + cfg &= ~Z188_ADC_GAIN;
> + cfg |= Z188_MODE_VOLTAGE;
> + writel(cfg, addr + i);
> + }
> +}
> +
> +static int men_z188_probe(struct mcb_device *dev,
> + const struct mcb_device_id *id)
> +{
> + struct z188_adc *adc;
> + struct iio_dev *indio_dev;
> + struct resource *mem;
> +
> + indio_dev = devm_iio_device_alloc(&dev->dev, sizeof(struct z188_adc));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + adc = iio_priv(indio_dev);
> + indio_dev->name = "z188-adc";
> + indio_dev->dev.parent = &dev->dev;
> + indio_dev->info = &z188_adc_info;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->channels = z188_adc_iio_channels;
> + indio_dev->num_channels = ARRAY_SIZE(z188_adc_iio_channels);
> +
> + mem = mcb_request_mem(dev, "z188-adc");
> + if (!mem)
> + return -ENOMEM;
> +
> + adc->base = ioremap(mem->start, resource_size(mem));
> + if (adc->base == NULL)
> + goto err;
> +
> + men_z188_config_channels(adc->base);
> +
> + adc->mem = mem;
> + mcb_set_drvdata(dev, indio_dev);
> +
> + return devm_iio_device_register(&dev->dev, indio_dev);
Using devm_iio_device_register means that the userspace interface
will only be removed after your remove function below had run.
That leaves room for some nasty race conditions.

The rule of thumb is don't use that particular devm function unless
absolutely everything is using devm interfaces. E.g. you don't have
any remove function at all.

Sorry, I missed this in the previous version.

> +
> +err:
> + mcb_release_mem(mem);
> + return -ENXIO;
> +}
> +
> +static void men_z188_remove(struct mcb_device *dev)
> +{
> + struct iio_dev *indio_dev = mcb_get_drvdata(dev);
> + struct z188_adc *adc = iio_priv(indio_dev);
> +
> + iounmap(adc->base);
Currently the userspace interface is still active after you've unmapped
this? Definitely a bad idea.
> + mcb_release_mem(adc->mem);
> +}
> +
> +static const struct mcb_device_id men_z188_ids[] = {
> + { .device = 0xbc },
> +};
> +MODULE_DEVICE_TABLE(mcb, men_z188_ids);
> +
> +static struct mcb_driver men_z188_driver = {
> + .driver = {
> + .name = "z188-adc",
> + .owner = THIS_MODULE,
> + },
> + .probe = men_z188_probe,
> + .remove = men_z188_remove,
> + .id_table = men_z188_ids,
> +};
> +module_mcb_driver(men_z188_driver);
> +
> +MODULE_AUTHOR("Johannes Thumshirn <[email protected]>");
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("IIO ADC driver for MEN 16z188 ADC Core");
> +MODULE_ALIAS("mcb:16z188");
> --
> 1.8.5.3
>
> --
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