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[PATCH v4 00/23] FSI device driver implementation

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  [PATCH v4 00/23] FSI device driver implementation Christopher Bostic <cbostic@linux.vnet.ibm.com> - 2017-03-29 19:50 +0200
    [PATCH v4 16/23] drivers/fsi: Add tracepoints for low-level operations Christopher Bostic <cbostic@linux.vnet.ibm.com> - 2017-03-29 19:50 +0200
    [PATCH v4 10/23] drivers/fsi: Add device read/write/peek API Christopher Bostic <cbostic@linux.vnet.ibm.com> - 2017-03-29 19:50 +0200
    [PATCH v4 22/23] drivers/fsi: Add hub master support Christopher Bostic <cbostic@linux.vnet.ibm.com> - 2017-03-29 19:50 +0200
    [PATCH v4 12/23] drivers/fsi: Add documentation for GPIO bindings Christopher Bostic <cbostic@linux.vnet.ibm.com> - 2017-03-29 19:50 +0200
      Re: [PATCH v4 12/23] drivers/fsi: Add documentation for GPIO bindings Rob Herring <robh@kernel.org> - 2017-04-03 17:30 +0200
    [PATCH v4 05/23] drivers/fsi: Add slave & master read/write APIs Christopher Bostic <cbostic@linux.vnet.ibm.com> - 2017-03-29 19:50 +0200
    [PATCH v4 18/23] drivers/fsi: Document FSI master sysfs files in ABI Christopher Bostic <cbostic@linux.vnet.ibm.com> - 2017-03-29 19:50 +0200
    [PATCH v4 01/23] drivers/fsi: Add fsi master definition Christopher Bostic <cbostic@linux.vnet.ibm.com> - 2017-03-29 19:50 +0200
    [PATCH v4 07/23] drivers/fsi: Implement slave initialisation Christopher Bostic <cbostic@linux.vnet.ibm.com> - 2017-03-29 19:50 +0200
    [PATCH v4 20/23] drivers/fsi/gpio: Add tracepoints for GPIO master Christopher Bostic <cbostic@linux.vnet.ibm.com> - 2017-03-29 19:50 +0200
    [PATCH v4 13/23] drivers/fsi: Add client driver register utilities Christopher Bostic <cbostic@linux.vnet.ibm.com> - 2017-03-29 19:50 +0200
    [PATCH v4 14/23] drivers/fsi: Add sysfs files for FSI master & slave accesses Christopher Bostic <cbostic@linux.vnet.ibm.com> - 2017-03-29 19:50 +0200
    [PATCH v4 15/23] drivers/fsi: expose direct-access slave API Christopher Bostic <cbostic@linux.vnet.ibm.com> - 2017-03-29 19:50 +0200
    [PATCH v4 04/23] drivers/fsi: Add crc4 helpers Christopher Bostic <cbostic@linux.vnet.ibm.com> - 2017-03-29 20:00 +0200
    [PATCH v4 02/23] drivers/fsi: Add slave definition Christopher Bostic <cbostic@linux.vnet.ibm.com> - 2017-03-29 20:00 +0200
    [PATCH v4 08/23] drivers/fsi: Set slave SMODE to init communication Christopher Bostic <cbostic@linux.vnet.ibm.com> - 2017-03-29 20:00 +0200
    [PATCH v4 03/23] drivers/fsi: Add empty master scan Christopher Bostic <cbostic@linux.vnet.ibm.com> - 2017-03-29 20:00 +0200

#1612195 — [PATCH v4 00/23] FSI device driver implementation

Implementation of the IBM 'Flexible Support Interface' (FSI) bus device
driver. FSI is a high fan out serial bus consisting of a clock and a serial
data line capable of running at speeds up to 166 MHz.

This set provides the basic framework to add FSI extensions to the
Linux bus and device models. Master specific implementations are
defined to utilize the core FSI function.

In Linux, we have a core FSI "bus type", along with drivers for FSI
masters and engines.

The FSI master drivers expose a read/write interface to the bus address
space. The master drivers are under drivers/fsi/fsi-master-*.c.

The core handles probing and discovery of slaves and slave
engines, using those read/write interfaces. It is responsible for
creating the endpoint Linux devices corresponding to the discovered
engines on each slave.

Slave engines are identified by an 'engine' type, and an optional
version. Engine, a.k.a. client, drivers are matched and bound to these
engines during discovery.

This patch set does not include extended FSI function such as:
    *  Cascaded master support
    *  Application layer hot plug notification
    *  Application layer FSI bus status interface

Common FSI terminology:

* Master
    Controller of the FSI bus.  Only the master is allowed to control the
    clock line and is the initiator of all transactions on a bus.

* Slave
    The receiver or target of a master initiated transaction.  The slave
    cannot initiate communications on a bus and must respond to any
    master requests for data.

* CFAM
    Stands for Common Field replaceable unit Access Macro.  A CFAM is an
    ASIC residing in any device requiring FSI communications. CFAMs
    consist of an array of hardware 'engines' used for various purposes.
    I2C masters, UARTs, General Purpose IO hardware are common types of
    these engines.

* Configuration Space / Table
    A table contained at the beginning of each CFAM address space.
    This table lists information such as the CFAM's ID, which engine types
    and versions it has available, as well as its addressing range.

* FSI Engine driver
    A device driver that registers with the FSI core so that it can access
    devices it owns on an FSI bus.

* Hub
    An FSI master that connects to an upstream 'primary' master allowing
    high fanout of target devices.

----
Changes in v4:
   - endianness: the _read() and _write() APIs are now all *bus endian*,
     so will be the same on all platforms (the previous fsi patches
     exposed as (BMC/FSP) CPU endian, which is variable).
   - device tree: Remove the "ibm," prefix for the fsi core and GPIO
     master compatibility strings, as they're not describing
     IBM-specific
   - device model: Create separate struct devices for each FSI
     master, which fits better with the Linux device model, and allows
     addition of sysfs attributes that are implemented by the fsi core
   - sysfs: there are now sysfs facilities for break and term. Raw
     file supports reads and writes of arbitrary sizes.
   - GPIO master: split the xfer() logic out a little, so that the
     response handling & DPOLL retry mechanism is more obvious
   - GPIO master: simplifications for message construction
   - GPIO master: fixes for some CRC calculations
   - GPIO master: issue TERM in response to DPOLL busy-loops
   - Error handling: rather than handle errors on (potentially) an entire
     cascaded read or write, the error handling is now down on a per-slave
     basis, where we try to reestablish communication in a more "gradual"
     manner, rather than sending a break immediately. May need to add a
     hook to percolate error recovery up to a slave's master but no need
     seen for that at present.
   - Hub master: this is now implemented as a fsi engine driver, as the
     fsi_slave_{read,write}() functions are exported (and the port count
     is available in the hMFSI configuration register)
     This means we need fewer special-cases in the fsi core.
   - Tracepoints: Add tracepoints for FSI core read & write, and another
     set for low-level GPIO in/out operations.

Changes in v3:
    - Patch set contained an invalid 18/18 test patch not
      meant for community review, corrected.

Changes in v2:
    - Change from atomic global for master number to ida simple
      interface.
    - Add valid pointer checks on register and unregister utils.
    - Move CRC calculation utilities out of driver to lib path.
    - Clean up white space issues.
    - Remove added list management of master devices and use
      instead the device_for_each_child method available in the
      bus.
    - Add new patch to document FSI bus functionality.
    - Add new patch documenting FSI gpio master.
    - Rearrage patch set to have documentation earlier than code
      implementing it.
    - Document all compatible strings used in device tree bindings.
    - Elaborate documentation definition of FSI GPIO master.
    - Describe in more detail what each GPIO FSI master pin is for.
    - Re-order compatible strings in example binding so that most
      specific device comes first.
    - Indicate proper activation order of all FSI GPIO master pins.
    - Fix an unmatched '>' bracket in the example for binding.
    - Bracket each element of the example bindings individually.
    - Add new patch documenting sysfs-bus-fsi attributes.
    - Merge FSI GPIO master init into probe function.
    - Set pin initial values at time of pin request.
    - Assign value of master->master.dev at probe time.
    - Use get_optional interface for all optional GPIO pins.

Chris Bostic (9):
  drivers/fsi: Set up links for slave communication
  drivers/fsi: Set slave SMODE to init communication
  drivers/fsi: Add master unscan
  drivers/fsi: Add documentation for GPIO bindings
  drivers/fsi: Add client driver register utilities
  drivers/fsi: Document FSI master sysfs files in ABI
  drivers/fsi: Add GPIO based FSI master
  drivers/fsi: Add SCOM FSI client device driver
  drivers/fsi: Add hub master support

Jeremy Kerr (14):
  drivers/fsi: Add fsi master definition
  drivers/fsi: Add slave definition
  drivers/fsi: Add empty master scan
  drivers/fsi: Add crc4 helpers
  drivers/fsi: Add slave & master read/write APIs
  drivers/fsi: Implement slave initialisation
  drivers/fsi: scan slaves & register devices
  drivers/fsi: Add device read/write/peek API
  drivers/fsi: Add sysfs files for FSI master & slave accesses
  drivers/fsi: expose direct-access slave API
  drivers/fsi: Add tracepoints for low-level operations
  drivers/fsi: Add error handling for slave communication errors
  drivers/fsi/gpio: Add tracepoints for GPIO master
  drivers/fsi: Use asynchronous slave mode

 Documentation/ABI/testing/sysfs-bus-fsi            |   6 +
 .../devicetree/bindings/fsi/fsi-master-gpio.txt    |  24 +
 arch/arm/boot/dts/aspeed-bmc-opp-palmetto.dts      |  10 +
 arch/arm/boot/dts/aspeed-bmc-opp-romulus.dts       |  12 +
 drivers/fsi/Kconfig                                |  26 +
 drivers/fsi/Makefile                               |   3 +
 drivers/fsi/fsi-core.c                             | 835 +++++++++++++++++++++
 drivers/fsi/fsi-master-gpio.c                      | 624 +++++++++++++++
 drivers/fsi/fsi-master-hub.c                       | 327 ++++++++
 drivers/fsi/fsi-master.h                           |  64 ++
 drivers/fsi/fsi-scom.c                             | 263 +++++++
 include/linux/fsi.h                                |  35 +-
 include/trace/events/fsi.h                         | 127 ++++
 include/trace/events/fsi_master_gpio.h             |  68 ++
 14 files changed, 2423 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-fsi
 create mode 100644 Documentation/devicetree/bindings/fsi/fsi-master-gpio.txt
 create mode 100644 drivers/fsi/fsi-master-gpio.c
 create mode 100644 drivers/fsi/fsi-master-hub.c
 create mode 100644 drivers/fsi/fsi-master.h
 create mode 100644 drivers/fsi/fsi-scom.c
 create mode 100644 include/trace/events/fsi.h
 create mode 100644 include/trace/events/fsi_master_gpio.h

-- 
1.8.2.2

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#1612196 — [PATCH v4 16/23] drivers/fsi: Add tracepoints for low-level operations

From: Jeremy Kerr <jk@ozlabs.org>

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
---
 drivers/fsi/fsi-core.c     |  27 +++++++---
 include/trace/events/fsi.h | 127 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 148 insertions(+), 6 deletions(-)
 create mode 100644 include/trace/events/fsi.h

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index f7e55e7..09becec 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -21,6 +21,9 @@
 
 #include "fsi-master.h"
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/fsi.h>
+
 #define FSI_SLAVE_CONF_NEXT_MASK	0x80000000
 #define FSI_SLAVE_CONF_SLOTS_MASK	0x00ff0000
 #define FSI_SLAVE_CONF_SLOTS_SHIFT	16
@@ -541,11 +544,16 @@ static int fsi_master_read(struct fsi_master *master, int link,
 {
 	int rc;
 
+	trace_fsi_master_read(master, link, slave_id, addr, size);
+
 	rc = fsi_check_access(addr, size);
-	if (rc)
-		return rc;
+	if (!rc)
+		rc = master->read(master, link, slave_id, addr, val, size);
+
+	trace_fsi_master_rw_result(master, link, slave_id, addr, size,
+			false, val, rc);
 
-	return master->read(master, link, slave_id, addr, val, size);
+	return rc;
 }
 
 static int fsi_master_write(struct fsi_master *master, int link,
@@ -553,11 +561,16 @@ static int fsi_master_write(struct fsi_master *master, int link,
 {
 	int rc;
 
+	trace_fsi_master_write(master, link, slave_id, addr, size, val);
+
 	rc = fsi_check_access(addr, size);
-	if (rc)
-		return rc;
+	if (!rc)
+		rc = master->write(master, link, slave_id, addr, val, size);
 
-	return master->write(master, link, slave_id, addr, val, size);
+	trace_fsi_master_rw_result(master, link, slave_id, addr, size,
+			true, val, rc);
+
+	return rc;
 }
 
 static int fsi_master_link_enable(struct fsi_master *master, int link)
@@ -573,6 +586,8 @@ static int fsi_master_link_enable(struct fsi_master *master, int link)
  */
 static int fsi_master_break(struct fsi_master *master, int link)
 {
+	trace_fsi_master_break(master, link);
+
 	if (master->send_break)
 		return master->send_break(master, link);
 
diff --git a/include/trace/events/fsi.h b/include/trace/events/fsi.h
new file mode 100644
index 0000000..ac74a30
--- /dev/null
+++ b/include/trace/events/fsi.h
@@ -0,0 +1,127 @@
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM fsi
+
+#if !defined(_TRACE_FSI_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_FSI_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(fsi_master_read,
+	TP_PROTO(const struct fsi_master *master, int link, int id,
+			uint32_t addr, size_t size),
+	TP_ARGS(master, link, id, addr, size),
+	TP_STRUCT__entry(
+		__field(int,	master_idx)
+		__field(int,	link)
+		__field(int,	id)
+		__field(__u32,	addr)
+		__field(size_t,	size)
+	),
+	TP_fast_assign(
+		__entry->master_idx = master->idx;
+		__entry->link = link;
+		__entry->id = id;
+		__entry->addr = addr;
+		__entry->size = size;
+	),
+	TP_printk("fsi%d:%02d:%02d %08x[%zd]",
+		__entry->master_idx,
+		__entry->link,
+		__entry->id,
+		__entry->addr,
+		__entry->size
+	)
+);
+
+TRACE_EVENT(fsi_master_write,
+	TP_PROTO(const struct fsi_master *master, int link, int id,
+			uint32_t addr, size_t size, const void *data),
+	TP_ARGS(master, link, id, addr, size, data),
+	TP_STRUCT__entry(
+		__field(int,	master_idx)
+		__field(int,	link)
+		__field(int,	id)
+		__field(__u32,	addr)
+		__field(size_t,	size)
+		__field(__u32,	data)
+	),
+	TP_fast_assign(
+		__entry->master_idx = master->idx;
+		__entry->link = link;
+		__entry->id = id;
+		__entry->addr = addr;
+		__entry->size = size;
+		__entry->data = 0;
+		memcpy(&__entry->data, data, size);
+	),
+	TP_printk("fsi%d:%02d:%02d %08x[%zd] <= {%*ph}",
+		__entry->master_idx,
+		__entry->link,
+		__entry->id,
+		__entry->addr,
+		__entry->size,
+		__entry->size, &__entry->data
+	)
+);
+
+TRACE_EVENT(fsi_master_rw_result,
+	TP_PROTO(const struct fsi_master *master, int link, int id,
+			uint32_t addr, size_t size,
+			bool write, const void *data, int ret),
+	TP_ARGS(master, link, id, addr, size, write, data, ret),
+	TP_STRUCT__entry(
+		__field(int,	master_idx)
+		__field(int,	link)
+		__field(int,	id)
+		__field(__u32,	addr)
+		__field(size_t,	size)
+		__field(bool,	write)
+		__field(__u32,	data)
+		__field(int,	ret)
+	),
+	TP_fast_assign(
+		__entry->master_idx = master->idx;
+		__entry->link = link;
+		__entry->id = id;
+		__entry->addr = addr;
+		__entry->size = size;
+		__entry->write = write;
+		__entry->data = 0;
+		__entry->ret = ret;
+		if (__entry->write || !__entry->ret)
+			memcpy(&__entry->data, data, size);
+	),
+	TP_printk("fsi%d:%02d:%02d %08x[%zd] %s {%*ph} ret %d",
+		__entry->master_idx,
+		__entry->link,
+		__entry->id,
+		__entry->addr,
+		__entry->size,
+		__entry->write ? "<=" : "=>",
+		__entry->size, &__entry->data,
+		__entry->ret
+	)
+);
+
+TRACE_EVENT(fsi_master_break,
+	TP_PROTO(const struct fsi_master *master, int link),
+	TP_ARGS(master, link),
+	TP_STRUCT__entry(
+		__field(int,	master_idx)
+		__field(int,	link)
+	),
+	TP_fast_assign(
+		__entry->master_idx = master->idx;
+		__entry->link = link;
+	),
+	TP_printk("fsi%d:%d",
+		__entry->master_idx,
+		__entry->link
+	)
+);
+
+
+#endif /* _TRACE_FSI_H */
+
+#include <trace/define_trace.h>
-- 
1.8.2.2

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#1612197 — [PATCH v4 10/23] drivers/fsi: Add device read/write/peek API

From: Jeremy Kerr <jk@ozlabs.org>

This change introduces the fsi device API: simple read, write and peek
accessors for the devices' address spaces.

Includes contributions from Chris Bostic <cbostic@linux.vnet.ibm.com>
and Edward A. James <eajames@us.ibm.com>.

Signed-off-by: Edward A. James <eajames@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
 drivers/fsi/fsi-core.c | 33 +++++++++++++++++++++++++++++++++
 include/linux/fsi.h    |  7 ++++++-
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index a8faa89..4da0b030 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -32,6 +32,8 @@
 #define FSI_SLAVE_CONF_CRC_MASK		0x0000000f
 #define FSI_SLAVE_CONF_DATA_BITS	28
 
+#define FSI_PEEK_BASE			0x410
+
 static const int engine_page_size = 0x400;
 
 #define FSI_SLAVE_BASE			0x800
@@ -73,9 +75,40 @@ static int fsi_master_read(struct fsi_master *master, int link,
 		uint8_t slave_id, uint32_t addr, void *val, size_t size);
 static int fsi_master_write(struct fsi_master *master, int link,
 		uint8_t slave_id, uint32_t addr, const void *val, size_t size);
+static int fsi_slave_read(struct fsi_slave *slave, uint32_t addr,
+		void *val, size_t size);
+static int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
+		const void *val, size_t size);
 
 /* FSI endpoint-device support */
 
+int fsi_device_read(struct fsi_device *dev, uint32_t addr, void *val,
+		size_t size)
+{
+	if (addr > dev->size || size > dev->size || addr > dev->size - size)
+		return -EINVAL;
+
+	return fsi_slave_read(dev->slave, dev->addr + addr, val, size);
+}
+EXPORT_SYMBOL_GPL(fsi_device_read);
+
+int fsi_device_write(struct fsi_device *dev, uint32_t addr, const void *val,
+		size_t size)
+{
+	if (addr > dev->size || size > dev->size || addr > dev->size - size)
+		return -EINVAL;
+
+	return fsi_slave_write(dev->slave, dev->addr + addr, val, size);
+}
+EXPORT_SYMBOL_GPL(fsi_device_write);
+
+int fsi_device_peek(struct fsi_device *dev, void *val)
+{
+	uint32_t addr = FSI_PEEK_BASE + ((dev->unit - 2) * sizeof(uint32_t));
+
+	return fsi_slave_read(dev->slave, addr, val, sizeof(uint32_t));
+}
+
 static void fsi_device_release(struct device *_device)
 {
 	struct fsi_device *device = to_fsi_dev(_device);
diff --git a/include/linux/fsi.h b/include/linux/fsi.h
index efa55ba..66bce48 100644
--- a/include/linux/fsi.h
+++ b/include/linux/fsi.h
@@ -27,6 +27,12 @@ struct fsi_device {
 	uint32_t		size;
 };
 
+extern int fsi_device_read(struct fsi_device *dev, uint32_t addr,
+		void *val, size_t size);
+extern int fsi_device_write(struct fsi_device *dev, uint32_t addr,
+		const void *val, size_t size);
+extern int fsi_device_peek(struct fsi_device *dev, void *val);
+
 struct fsi_device_id {
 	u8	engine_type;
 	u8	version;
@@ -40,7 +46,6 @@ struct fsi_device_id {
 #define FSI_DEVICE_VERSIONED(t, v) \
 	.engine_type = (t), .version = (v),
 
-
 struct fsi_driver {
 	struct device_driver		drv;
 	const struct fsi_device_id	*id_table;
-- 
1.8.2.2

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#1612198 — [PATCH v4 22/23] drivers/fsi: Add hub master support

From: Chris Bostic <cbostic@linux.vnet.ibm.com>

Add an engine driver to expose a "hub" FSI master - which has a set of
control registers in the engine address space, and uses a chunk of the
slave address space for actual FSI communication.

Additional changes from Jeremy Kerr <jk@ozlabs.org>.

Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
 drivers/fsi/Kconfig          |   9 ++
 drivers/fsi/Makefile         |   1 +
 drivers/fsi/fsi-master-hub.c | 327 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 337 insertions(+)
 create mode 100644 drivers/fsi/fsi-master-hub.c

diff --git a/drivers/fsi/Kconfig b/drivers/fsi/Kconfig
index 0fa265c..e1156b4 100644
--- a/drivers/fsi/Kconfig
+++ b/drivers/fsi/Kconfig
@@ -18,6 +18,15 @@ config FSI_MASTER_GPIO
 	---help---
 	This option enables a FSI master driver using GPIO lines.
 
+config FSI_MASTER_HUB
+	tristate "FSI hub master"
+	depends on FSI
+	---help---
+	This option enables a FSI hub master driver.  Hub is a type of FSI
+	master that is connected to the upstream master via a slave.  Hubs
+	allow chaining of FSI links to an arbitrary depth.  This allows for
+	a high target device fanout.
+
 config FSI_SCOM
 	tristate "SCOM FSI client device driver"
 	depends on FSI
diff --git a/drivers/fsi/Makefile b/drivers/fsi/Makefile
index 3466f08..65eb99d 100644
--- a/drivers/fsi/Makefile
+++ b/drivers/fsi/Makefile
@@ -1,4 +1,5 @@
 
 obj-$(CONFIG_FSI) += fsi-core.o
+obj-$(CONFIG_FSI_MASTER_HUB) += fsi-master-hub.o
 obj-$(CONFIG_FSI_MASTER_GPIO) += fsi-master-gpio.o
 obj-$(CONFIG_FSI_SCOM) += fsi-scom.o
diff --git a/drivers/fsi/fsi-master-hub.c b/drivers/fsi/fsi-master-hub.c
new file mode 100644
index 0000000..133b9bf
--- /dev/null
+++ b/drivers/fsi/fsi-master-hub.c
@@ -0,0 +1,327 @@
+/*
+ * FSI hub master driver
+ *
+ * Copyright (C) IBM Corporation 2016
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#include <linux/delay.h>
+#include <linux/fsi.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include "fsi-master.h"
+
+/* Control Registers */
+#define FSI_MMODE		0x0		/* R/W: mode */
+#define FSI_MDLYR		0x4		/* R/W: delay */
+#define FSI_MCRSP		0x8		/* R/W: clock rate */
+#define FSI_MENP0		0x10		/* R/W: enable */
+#define FSI_MLEVP0		0x18		/* R: plug detect */
+#define FSI_MSENP0		0x18		/* S: Set enable */
+#define FSI_MCENP0		0x20		/* C: Clear enable */
+#define FSI_MAEB		0x70		/* R: Error address */
+#define FSI_MVER		0x74		/* R: master version/type */
+#define FSI_MRESP0		0xd0		/* W: Port reset */
+#define FSI_MESRB0		0x1d0		/* R: Master error status */
+#define FSI_MRESB0		0x1d0		/* W: Reset bridge */
+#define FSI_MECTRL		0x2e0		/* W: Error control */
+
+/* MMODE: Mode control */
+#define FSI_MMODE_EIP		0x80000000	/* Enable interrupt polling */
+#define FSI_MMODE_ECRC		0x40000000	/* Enable error recovery */
+#define FSI_MMODE_EPC		0x10000000	/* Enable parity checking */
+#define FSI_MMODE_P8_TO_LSB	0x00000010	/* Timeout value LSB */
+						/*   MSB=1, LSB=0 is 0.8 ms */
+						/*   MSB=0, LSB=1 is 0.9 ms */
+#define FSI_MMODE_CRS0SHFT	18		/* Clk rate selection 0 shift */
+#define FSI_MMODE_CRS0MASK	0x3ff		/* Clk rate selection 0 mask */
+#define FSI_MMODE_CRS1SHFT	8		/* Clk rate selection 1 shift */
+#define FSI_MMODE_CRS1MASK	0x3ff		/* Clk rate selection 1 mask */
+
+/* MRESB: Reset brindge */
+#define FSI_MRESB_RST_GEN	0x80000000	/* General reset */
+#define FSI_MRESB_RST_ERR	0x40000000	/* Error Reset */
+
+/* MRESB: Reset port */
+#define FSI_MRESP_RST_ALL_MASTER 0x20000000	/* Reset all FSI masters */
+#define FSI_MRESP_RST_ALL_LINK	0x10000000	/* Reset all FSI port contr. */
+#define FSI_MRESP_RST_MCR	0x08000000	/* Reset FSI master reg. */
+#define FSI_MRESP_RST_PYE	0x04000000	/* Reset FSI parity error */
+#define FSI_MRESP_RST_ALL	0xfc000000	/* Reset any error */
+
+/* MECTRL: Error control */
+#define FSI_MECTRL_EOAE		0x8000		/* Enable machine check when */
+						/* master 0 in error */
+#define FSI_MECTRL_P8_AUTO_TERM	0x4000		/* Auto terminate */
+
+#define FSI_ENGID_HUB_MASTER		0x1c
+#define FSI_HUB_LINK_OFFSET		0x80000
+#define FSI_HUB_LINK_SIZE		0x80000
+#define FSI_HUB_MASTER_MAX_LINKS	8
+
+#define FSI_LINK_ENABLE_SETUP_TIME	10	/* in mS */
+
+/*
+ * FSI hub master support
+ *
+ * A hub master increases the number of potential target devices that the
+ * primary FSI master can access. For each link a primary master supports,
+ * each of those links can in turn be chained to a hub master with multiple
+ * links of its own.
+ *
+ * The hub is controlled by a set of control registers exposed as a regular fsi
+ * device (the hub->upstream device), and provides access to the downstream FSI
+ * bus as through an address range on the slave itself (->addr and ->size).
+ *
+ * [This differs from "cascaded" masters, which expose the entire downstream
+ * bus entirely through the fsi device address range, and so have a smaller
+ * accessible address space.]
+ */
+struct fsi_master_hub {
+	struct fsi_master	master;
+	struct fsi_device	*upstream;
+	uint32_t		addr, size;	/* slave-relative addr of */
+						/* master address space */
+};
+
+#define to_fsi_master_hub(m) container_of(m, struct fsi_master_hub, master)
+
+static int hub_master_read(struct fsi_master *master, int link,
+			uint8_t id, uint32_t addr, void *val, size_t size)
+{
+	struct fsi_master_hub *hub = to_fsi_master_hub(master);
+
+	if (id != 0)
+		return -EINVAL;
+
+	addr += hub->addr + (link * FSI_HUB_LINK_SIZE);
+	return fsi_slave_read(hub->upstream->slave, addr, val, size);
+}
+
+static int hub_master_write(struct fsi_master *master, int link,
+			uint8_t id, uint32_t addr, const void *val, size_t size)
+{
+	struct fsi_master_hub *hub = to_fsi_master_hub(master);
+
+	if (id != 0)
+		return -EINVAL;
+
+	addr += hub->addr + (link * FSI_HUB_LINK_SIZE);
+	return fsi_slave_write(hub->upstream->slave, addr, val, size);
+}
+
+static int hub_master_break(struct fsi_master *master, int link)
+{
+	uint32_t addr, cmd;
+
+	addr = 0x4;
+	cmd = cpu_to_be32(0xc0de0000);
+
+	return hub_master_write(master, link, 0, addr, &cmd, sizeof(cmd));
+}
+
+static int hub_master_link_enable(struct fsi_master *master, int link)
+{
+	struct fsi_master_hub *hub = to_fsi_master_hub(master);
+	int idx, bit;
+	__be32 reg;
+	int rc;
+
+	idx = link / 32;
+	bit = link % 32;
+
+	reg = cpu_to_be32(0x80000000 >> bit);
+
+	rc = fsi_device_write(hub->upstream, FSI_MSENP0 + (4 * idx), &reg, 4);
+
+	mdelay(FSI_LINK_ENABLE_SETUP_TIME);
+
+	fsi_device_read(hub->upstream, FSI_MENP0 + (4 * idx), &reg, 4);
+
+	return rc;
+}
+
+static void hub_master_release(struct device *dev)
+{
+	struct fsi_master_hub *hub = to_fsi_master_hub(dev_to_fsi_master(dev));
+
+	kfree(hub);
+}
+
+/* mmode encoders */
+static inline u32 fsi_mmode_crs0(u32 x)
+{
+	return (x & FSI_MMODE_CRS0MASK) << FSI_MMODE_CRS0SHFT;
+}
+
+static inline u32 fsi_mmode_crs1(u32 x)
+{
+	return (x & FSI_MMODE_CRS1MASK) << FSI_MMODE_CRS1SHFT;
+}
+
+static int hub_master_init(struct fsi_master_hub *hub)
+{
+	struct fsi_device *dev = hub->upstream;
+	__be32 reg;
+	int rc;
+
+	reg = cpu_to_be32(FSI_MRESP_RST_ALL_MASTER | FSI_MRESP_RST_ALL_LINK
+			| FSI_MRESP_RST_MCR | FSI_MRESP_RST_PYE);
+	rc = fsi_device_write(dev, FSI_MRESP0, &reg, sizeof(reg));
+	if (rc)
+		return rc;
+
+	/* Initialize the MFSI (hub master) engine */
+	reg = cpu_to_be32(FSI_MRESP_RST_ALL_MASTER | FSI_MRESP_RST_ALL_LINK
+			| FSI_MRESP_RST_MCR | FSI_MRESP_RST_PYE);
+	rc = fsi_device_write(dev, FSI_MRESP0, &reg, sizeof(reg));
+	if (rc)
+		return rc;
+
+	reg = cpu_to_be32(FSI_MECTRL_EOAE | FSI_MECTRL_P8_AUTO_TERM);
+	rc = fsi_device_write(dev, FSI_MECTRL, &reg, sizeof(reg));
+	if (rc)
+		return rc;
+
+	reg = cpu_to_be32(FSI_MMODE_EIP | FSI_MMODE_ECRC | FSI_MMODE_EPC
+			| fsi_mmode_crs0(1) | fsi_mmode_crs1(1)
+			| FSI_MMODE_P8_TO_LSB);
+	rc = fsi_device_write(dev, FSI_MMODE, &reg, sizeof(reg));
+	if (rc)
+		return rc;
+
+	reg = cpu_to_be32(0xffff0000);
+	rc = fsi_device_write(dev, FSI_MDLYR, &reg, sizeof(reg));
+	if (rc)
+		return rc;
+
+	reg = ~0;
+	rc = fsi_device_write(dev, FSI_MSENP0, &reg, sizeof(reg));
+	if (rc)
+		return rc;
+
+	/* Leave enabled long enough for master logic to set up */
+	mdelay(FSI_LINK_ENABLE_SETUP_TIME);
+
+	rc = fsi_device_write(dev, FSI_MCENP0, &reg, sizeof(reg));
+	if (rc)
+		return rc;
+
+	rc = fsi_device_read(dev, FSI_MAEB, &reg, sizeof(reg));
+	if (rc)
+		return rc;
+
+	reg = cpu_to_be32(FSI_MRESP_RST_ALL_MASTER | FSI_MRESP_RST_ALL_LINK);
+	rc = fsi_device_write(dev, FSI_MRESP0, &reg, sizeof(reg));
+	if (rc)
+		return rc;
+
+	rc = fsi_device_read(dev, FSI_MLEVP0, &reg, sizeof(reg));
+	if (rc)
+		return rc;
+
+	/* Reset the master bridge */
+	reg = cpu_to_be32(FSI_MRESB_RST_GEN);
+	rc = fsi_device_write(dev, FSI_MRESB0, &reg, sizeof(reg));
+	if (rc)
+		return rc;
+
+	reg = cpu_to_be32(FSI_MRESB_RST_ERR);
+	return fsi_device_write(dev, FSI_MRESB0, &reg, sizeof(reg));
+}
+
+static int hub_master_probe(struct device *dev)
+{
+	struct fsi_device *fsi_dev = to_fsi_dev(dev);
+	struct fsi_master_hub *hub;
+	uint32_t reg, links;
+	__be32 __reg;
+	int rc;
+
+	rc = fsi_device_read(fsi_dev, FSI_MVER, &__reg, sizeof(__reg));
+	if (rc)
+		return rc;
+
+	reg = be32_to_cpu(__reg);
+	links = (reg >> 8) & 0xff;
+	dev_info(dev, "hub version %08x (%d links)\n", reg, links);
+
+	rc = fsi_slave_claim_range(fsi_dev->slave, FSI_HUB_LINK_OFFSET,
+			FSI_HUB_LINK_SIZE * links);
+	if (rc) {
+		dev_err(dev, "can't claim slave address range for links");
+		return rc;
+	}
+
+	hub = kzalloc(sizeof(*hub), GFP_KERNEL);
+	if (!hub) {
+		rc = -ENOMEM;
+		goto err_release;
+	}
+
+	hub->addr = FSI_HUB_LINK_OFFSET;
+	hub->size = FSI_HUB_LINK_SIZE * links;
+	hub->upstream = fsi_dev;
+
+	hub->master.dev.parent = dev;
+	hub->master.dev.release = hub_master_release;
+
+	hub->master.n_links = links;
+	hub->master.read = hub_master_read;
+	hub->master.write = hub_master_write;
+	hub->master.send_break = hub_master_break;
+	hub->master.link_enable = hub_master_link_enable;
+
+	dev_set_drvdata(dev, hub);
+
+	hub_master_init(hub);
+
+	rc = fsi_master_register(&hub->master);
+	if (!rc)
+		return 0;
+
+	kfree(hub);
+err_release:
+	fsi_slave_release_range(fsi_dev->slave, FSI_HUB_LINK_OFFSET,
+			FSI_HUB_LINK_SIZE * links);
+	return rc;
+}
+
+static int hub_master_remove(struct device *dev)
+{
+	struct fsi_master_hub *hub = dev_get_drvdata(dev);
+
+	fsi_master_unregister(&hub->master);
+	fsi_slave_release_range(hub->upstream->slave, hub->addr, hub->size);
+	return 0;
+}
+
+static struct fsi_device_id hub_master_ids[] = {
+	{
+		.engine_type = FSI_ENGID_HUB_MASTER,
+		.version = FSI_VERSION_ANY,
+	},
+	{ 0 }
+};
+
+static struct fsi_driver hub_master_driver = {
+	.id_table = hub_master_ids,
+	.drv = {
+		.name = "fsi-master-hub",
+		.bus = &fsi_bus_type,
+		.probe = hub_master_probe,
+		.remove = hub_master_remove,
+	}
+};
+
+module_fsi_driver(hub_master_driver);
+MODULE_LICENSE("GPL");
-- 
1.8.2.2

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#1612199 — [PATCH v4 12/23] drivers/fsi: Add documentation for GPIO bindings

From: Chris Bostic <cbostic@linux.vnet.ibm.com>

Add fsi master gpio device tree binding documentation

Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
 .../devicetree/bindings/fsi/fsi-master-gpio.txt    | 24 ++++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/fsi/fsi-master-gpio.txt

diff --git a/Documentation/devicetree/bindings/fsi/fsi-master-gpio.txt b/Documentation/devicetree/bindings/fsi/fsi-master-gpio.txt
new file mode 100644
index 0000000..a767259
--- /dev/null
+++ b/Documentation/devicetree/bindings/fsi/fsi-master-gpio.txt
@@ -0,0 +1,24 @@
+Device-tree bindings for gpio-based FSI master driver
+-----------------------------------------------------
+
+Required properties:
+ - compatible = "fsi-master-gpio";
+ - clock-gpios = <gpio-descriptor>;	: GPIO for FSI clock
+ - data-gpios = <gpio-descriptor>;	: GPIO for FSI data signal
+
+Optional properties:
+ - enable-gpios = <gpio-descriptor>;	: GPIO for enable signal
+ - trans-gpios = <gpio-descriptor>;	: GPIO for voltage translator enable
+ - mux-gpios = <gpio-descriptor>;	: GPIO for pin multiplexing with other
+                                          functions (eg, external FSI masters)
+
+Examples:
+
+    fsi-master {
+        compatible = "fsi-master-gpio", "fsi-master";
+        clock-gpios = <&gpio 0>;
+        data-gpios = <&gpio 1>;
+        enable-gpios = <&gpio 2>;
+        trans-gpios = <&gpio 3>;
+        mux-gpios = <&gpio 4>;
+    }
-- 
1.8.2.2

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#1615332 — Re: [PATCH v4 12/23] drivers/fsi: Add documentation for GPIO bindings

On Wed, Mar 29, 2017 at 12:43:29PM -0500, Christopher Bostic wrote:
> From: Chris Bostic <cbostic@linux.vnet.ibm.com>
> 
> Add fsi master gpio device tree binding documentation
> 
> Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
> Signed-off-by: Joel Stanley <joel@jms.id.au>
> ---
>  .../devicetree/bindings/fsi/fsi-master-gpio.txt    | 24 ++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/fsi/fsi-master-gpio.txt

Acked-by: Rob Herring <robh@kernel.org> 

But what happened to the bus description? There's never a need to 
describe slave devices (even discoverable buses like USB and PCI still 
need them sometimes)? As it stands now, I have no idea what FSI is from 
reading bindings/fsi/*.

Rob

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#1612200 — [PATCH v4 05/23] drivers/fsi: Add slave & master read/write APIs

From: Jeremy Kerr <jk@ozlabs.org>

Introduce functions to perform reads/writes on the slave address space;
these simply pass the request on the slave's master with the correct
link and slave ID.

We implement these on top of similar helpers for the master.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
---
 drivers/fsi/fsi-core.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 92 insertions(+)

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index 4bbca95..32698ed 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -32,6 +32,11 @@ struct fsi_slave {
 
 #define to_fsi_slave(d) container_of(d, struct fsi_slave, dev)
 
+static int fsi_master_read(struct fsi_master *master, int link,
+		uint8_t slave_id, uint32_t addr, void *val, size_t size);
+static int fsi_master_write(struct fsi_master *master, int link,
+		uint8_t slave_id, uint32_t addr, const void *val, size_t size);
+
 /* crc helpers */
 static const uint8_t crc4_tab[] = {
 	0x0, 0x7, 0xe, 0x9, 0xb, 0xc, 0x5, 0x2,
@@ -57,6 +62,58 @@ uint8_t fsi_crc4(uint8_t c, uint64_t x, int bits)
 EXPORT_SYMBOL_GPL(fsi_crc4);
 
 /* FSI slave support */
+static int fsi_slave_calc_addr(struct fsi_slave *slave, uint32_t *addrp,
+		uint8_t *idp)
+{
+	uint32_t addr = *addrp;
+	uint8_t id = *idp;
+
+	if (addr > slave->size)
+		return -EINVAL;
+
+	/* For 23 bit addressing, we encode the extra two bits in the slave
+	 * id (and the slave's actual ID needs to be 0).
+	 */
+	if (addr > 0x1fffff) {
+		if (slave->id != 0)
+			return -EINVAL;
+		id = (addr >> 21) & 0x3;
+		addr &= 0x1fffff;
+	}
+
+	*addrp = addr;
+	*idp = id;
+	return 0;
+}
+
+static int fsi_slave_read(struct fsi_slave *slave, uint32_t addr,
+			void *val, size_t size)
+{
+	uint8_t id = slave->id;
+	int rc;
+
+	rc = fsi_slave_calc_addr(slave, &addr, &id);
+	if (rc)
+		return rc;
+
+	return fsi_master_read(slave->master, slave->link, id,
+			addr, val, size);
+}
+
+static int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
+			const void *val, size_t size)
+{
+	uint8_t id = slave->id;
+	int rc;
+
+	rc = fsi_slave_calc_addr(slave, &addr, &id);
+	if (rc)
+		return rc;
+
+	return fsi_master_write(slave->master, slave->link, id,
+			addr, val, size);
+}
+
 static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
 {
 	/* todo: initialise slave device, perform engine scan */
@@ -65,6 +122,41 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
 }
 
 /* FSI master support */
+static int fsi_check_access(uint32_t addr, size_t size)
+{
+	if (size != 1 && size != 2 && size != 4)
+		return -EINVAL;
+
+	if ((addr & 0x3) != (size & 0x3))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int fsi_master_read(struct fsi_master *master, int link,
+		uint8_t slave_id, uint32_t addr, void *val, size_t size)
+{
+	int rc;
+
+	rc = fsi_check_access(addr, size);
+	if (rc)
+		return rc;
+
+	return master->read(master, link, slave_id, addr, val, size);
+}
+
+static int fsi_master_write(struct fsi_master *master, int link,
+		uint8_t slave_id, uint32_t addr, const void *val, size_t size)
+{
+	int rc;
+
+	rc = fsi_check_access(addr, size);
+	if (rc)
+		return rc;
+
+	return master->write(master, link, slave_id, addr, val, size);
+}
+
 static int fsi_master_scan(struct fsi_master *master)
 {
 	int link;
-- 
1.8.2.2

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#1612202 — [PATCH v4 18/23] drivers/fsi: Document FSI master sysfs files in ABI

From: Chris Bostic <cbostic@linux.vnet.ibm.com>

Add info for sysfs scan file in Documentaiton ABI/testing

Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
---
 Documentation/ABI/testing/sysfs-bus-fsi | 6 ++++++
 1 file changed, 6 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-fsi

diff --git a/Documentation/ABI/testing/sysfs-bus-fsi b/Documentation/ABI/testing/sysfs-bus-fsi
new file mode 100644
index 0000000..dfcbc1b
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-fsi
@@ -0,0 +1,6 @@
+What:           /sys/bus/platform/devices/fsi-master/scan
+KernelVersion:  4.9
+Contact:        cbostic@us.ibm.com
+Description:
+                Initiates a FSI master scan for all connected
+                slave devices on its links.
-- 
1.8.2.2

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#1612203 — [PATCH v4 01/23] drivers/fsi: Add fsi master definition

From: Jeremy Kerr <jk@ozlabs.org>

Add a `struct fsi_master` to represent a FSI master controller.

FSI master drivers register one of these structs to provide
device-specific of the standard operations: read/write/term/break and
link control.

Includes changes from Edward A. James <eajames@us.ibm.com> & Jeremy Kerr
<jk@ozlabs.org>.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
 drivers/fsi/fsi-core.c   | 35 +++++++++++++++++++++++++++++++++++
 drivers/fsi/fsi-master.h | 41 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 76 insertions(+)
 create mode 100644 drivers/fsi/fsi-master.h

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index 3d55bd5..ca02913 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -15,8 +15,43 @@
 
 #include <linux/device.h>
 #include <linux/fsi.h>
+#include <linux/idr.h>
 #include <linux/module.h>
 
+#include "fsi-master.h"
+
+static DEFINE_IDA(master_ida);
+
+/* FSI master support */
+int fsi_master_register(struct fsi_master *master)
+{
+	int rc;
+
+	if (!master)
+		return -EINVAL;
+
+	master->idx = ida_simple_get(&master_ida, 0, INT_MAX, GFP_KERNEL);
+	dev_set_name(&master->dev, "fsi%d", master->idx);
+
+	rc = device_register(&master->dev);
+	if (rc)
+		ida_simple_remove(&master_ida, master->idx);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(fsi_master_register);
+
+void fsi_master_unregister(struct fsi_master *master)
+{
+	if (master->idx >= 0) {
+		ida_simple_remove(&master_ida, master->idx);
+		master->idx = -1;
+	}
+
+	device_unregister(&master->dev);
+}
+EXPORT_SYMBOL_GPL(fsi_master_unregister);
+
 /* FSI core & Linux bus type definitions */
 
 static int fsi_bus_match(struct device *dev, struct device_driver *drv)
diff --git a/drivers/fsi/fsi-master.h b/drivers/fsi/fsi-master.h
new file mode 100644
index 0000000..7764b00
--- /dev/null
+++ b/drivers/fsi/fsi-master.h
@@ -0,0 +1,41 @@
+/*
+ * FSI master definitions. These comprise the core <--> master interface,
+ * to allow the core to interact with the (hardware-specific) masters.
+ *
+ * Copyright (C) IBM Corporation 2016
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#ifndef DRIVERS_FSI_MASTER_H
+#define DRIVERS_FSI_MASTER_H
+
+#include <linux/device.h>
+
+struct fsi_master {
+	struct device	dev;
+	int		idx;
+	int		n_links;
+	int		flags;
+	int		(*read)(struct fsi_master *, int link, uint8_t id,
+				uint32_t addr, void *val, size_t size);
+	int		(*write)(struct fsi_master *, int link, uint8_t id,
+				uint32_t addr, const void *val, size_t size);
+	int		(*term)(struct fsi_master *, int link, uint8_t id);
+	int		(*send_break)(struct fsi_master *, int link);
+	int		(*link_enable)(struct fsi_master *, int link);
+};
+
+#define dev_to_fsi_master(d) container_of(d, struct fsi_master, dev)
+
+extern int fsi_master_register(struct fsi_master *master);
+extern void fsi_master_unregister(struct fsi_master *master);
+
+#endif /* DRIVERS_FSI_MASTER_H */
-- 
1.8.2.2

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#1612204 — [PATCH v4 07/23] drivers/fsi: Implement slave initialisation

From: Jeremy Kerr <jk@ozlabs.org>

Implement fsi_slave_init: if we can read a chip ID, create fsi_slave
devices and register with the driver core.

Includes changes from Chris Bostic <cbostic@linux.vnet.ibm.com>.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
 drivers/fsi/fsi-core.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 64 insertions(+), 2 deletions(-)

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index 6e1cfdf..c705ca2 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -17,9 +17,12 @@
 #include <linux/fsi.h>
 #include <linux/idr.h>
 #include <linux/module.h>
+#include <linux/slab.h>
 
 #include "fsi-master.h"
 
+#define FSI_SLAVE_SIZE_23b		0x800000
+
 static DEFINE_IDA(master_ida);
 
 struct fsi_slave {
@@ -114,11 +117,70 @@ static int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
 			addr, val, size);
 }
 
+static void fsi_slave_release(struct device *dev)
+{
+	struct fsi_slave *slave = to_fsi_slave(dev);
+
+	kfree(slave);
+}
+
 static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
 {
-	/* todo: initialise slave device, perform engine scan */
+	struct fsi_slave *slave;
+	uint32_t chip_id;
+	uint8_t crc;
+	int rc;
+
+	/* Currently, we only support single slaves on a link, and use the
+	 * full 23-bit address range
+	 */
+	if (id != 0)
+		return -EINVAL;
+
+	rc = fsi_master_read(master, link, id, 0, &chip_id, sizeof(chip_id));
+	if (rc) {
+		dev_warn(&master->dev, "can't read slave %02x:%02x %d\n",
+				link, id, rc);
+		return -ENODEV;
+	}
+	chip_id = be32_to_cpu(chip_id);
+
+	crc = fsi_crc4(0, chip_id, 32);
+	if (crc) {
+		dev_warn(&master->dev, "slave %02x:%02x invalid chip id CRC!\n",
+				link, id);
+		return -EIO;
+	}
+
+	dev_info(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n",
+			chip_id, master->idx, link, id);
+
+	/* We can communicate with a slave; create the slave device and
+	 * register.
+	 */
+	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
+	if (!slave)
+		return -ENOMEM;
+
+	slave->master = master;
+	slave->dev.parent = &master->dev;
+	slave->dev.release = fsi_slave_release;
+	slave->link = link;
+	slave->id = id;
+	slave->size = FSI_SLAVE_SIZE_23b;
+
+	dev_set_name(&slave->dev, "slave@%02x:%02x", link, id);
+	rc = device_register(&slave->dev);
+	if (rc < 0) {
+		dev_warn(&master->dev, "failed to create slave device: %d\n",
+				rc);
+		put_device(&slave->dev);
+		return rc;
+	}
+
+	/* todo: perform engine scan */
 
-	return -ENODEV;
+	return rc;
 }
 
 /* FSI master support */
-- 
1.8.2.2

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#1612205 — [PATCH v4 20/23] drivers/fsi/gpio: Add tracepoints for GPIO master

From: Jeremy Kerr <jk@ozlabs.org>

Add trace points for key GPIO operations of the GPIO based FSI
master.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
---
 drivers/fsi/fsi-master-gpio.c          |  9 +++++
 include/trace/events/fsi_master_gpio.h | 68 ++++++++++++++++++++++++++++++++++
 2 files changed, 77 insertions(+)
 create mode 100644 include/trace/events/fsi_master_gpio.h

diff --git a/drivers/fsi/fsi-master-gpio.c b/drivers/fsi/fsi-master-gpio.c
index 0bf5caa..84d5595 100644
--- a/drivers/fsi/fsi-master-gpio.c
+++ b/drivers/fsi/fsi-master-gpio.c
@@ -61,6 +61,9 @@ struct fsi_master_gpio {
 	struct gpio_desc	*gpio_mux;	/* Mux control */
 };
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/fsi_master_gpio.h>
+
 #define to_fsi_master_gpio(m) container_of(m, struct fsi_master_gpio, master)
 
 struct fsi_gpio_msg {
@@ -128,6 +131,8 @@ static void serial_in(struct fsi_master_gpio *master, struct fsi_gpio_msg *msg,
 		msg->msg |= ~in_bit & 0x1;	/* Data is negative active */
 	}
 	msg->bits += num_bits;
+
+	trace_fsi_master_gpio_in(master, num_bits, msg->msg);
 }
 
 static void serial_out(struct fsi_master_gpio *master,
@@ -139,6 +144,8 @@ static void serial_out(struct fsi_master_gpio *master,
 	uint64_t last_bit = ~0;
 	int next_bit;
 
+	trace_fsi_master_gpio_out(master, cmd->bits, cmd->msg);
+
 	if (!cmd->bits) {
 		dev_warn(master->dev, "trying to output 0 bits\n");
 		return;
@@ -464,6 +471,8 @@ static int fsi_master_gpio_break(struct fsi_master *_master, int link)
 	if (link != 0)
 		return -ENODEV;
 
+	trace_fsi_master_gpio_break(master);
+
 	set_sda_output(master, 1);
 	sda_out(master, 1);
 	clock_toggle(master, FSI_PRE_BREAK_CLOCKS);
diff --git a/include/trace/events/fsi_master_gpio.h b/include/trace/events/fsi_master_gpio.h
new file mode 100644
index 0000000..11b36c1
--- /dev/null
+++ b/include/trace/events/fsi_master_gpio.h
@@ -0,0 +1,68 @@
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM fsi_master_gpio
+
+#if !defined(_TRACE_FSI_MASTER_GPIO_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_FSI_MASTER_GPIO_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(fsi_master_gpio_in,
+	TP_PROTO(const struct fsi_master_gpio *master, int bits, uint64_t msg),
+	TP_ARGS(master, bits, msg),
+	TP_STRUCT__entry(
+		__field(int,	master_idx)
+		__field(int,	bits)
+		__field(uint64_t, msg)
+	),
+	TP_fast_assign(
+		__entry->master_idx = master->master.idx;
+		__entry->bits = bits;
+		__entry->msg  = msg & ((1ull<<bits) - 1);
+	),
+	TP_printk("fsi-gpio%d => %0*llx[%d]",
+		__entry->master_idx,
+		(__entry->bits + 3) / 4,
+		__entry->msg,
+		__entry->bits
+	)
+);
+
+TRACE_EVENT(fsi_master_gpio_out,
+	TP_PROTO(const struct fsi_master_gpio *master, int bits, uint64_t msg),
+	TP_ARGS(master, bits, msg),
+	TP_STRUCT__entry(
+		__field(int,	master_idx)
+		__field(int,	bits)
+		__field(uint64_t, msg)
+	),
+	TP_fast_assign(
+		__entry->master_idx = master->master.idx;
+		__entry->bits = bits;
+		__entry->msg  = msg & ((1ull<<bits) - 1);
+	),
+	TP_printk("fsi-gpio%d <= %0*llx[%d]",
+		__entry->master_idx,
+		(__entry->bits + 3) / 4,
+		__entry->msg,
+		__entry->bits
+	)
+);
+
+TRACE_EVENT(fsi_master_gpio_break,
+	TP_PROTO(const struct fsi_master_gpio *master),
+	TP_ARGS(master),
+	TP_STRUCT__entry(
+		__field(int,	master_idx)
+	),
+	TP_fast_assign(
+		__entry->master_idx = master->master.idx;
+	),
+	TP_printk("fsi-gpio%d ----break---",
+		__entry->master_idx
+	)
+);
+
+#endif /* _TRACE_FSI_MASTER_GPIO_H */
+
+#include <trace/define_trace.h>
-- 
1.8.2.2

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#1612206 — [PATCH v4 13/23] drivers/fsi: Add client driver register utilities

From: Chris Bostic <cbostic@linux.vnet.ibm.com>

Add driver_register and driver_unregister wrappers for FSI.

Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
 drivers/fsi/fsi-core.c | 17 +++++++++++++++++
 include/linux/fsi.h    | 12 ++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index 75d2a88..4359e26 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -585,6 +585,23 @@ static int fsi_bus_match(struct device *dev, struct device_driver *drv)
 	return 0;
 }
 
+int fsi_driver_register(struct fsi_driver *fsi_drv)
+{
+	if (!fsi_drv)
+		return -EINVAL;
+	if (!fsi_drv->id_table)
+		return -EINVAL;
+
+	return driver_register(&fsi_drv->drv);
+}
+EXPORT_SYMBOL_GPL(fsi_driver_register);
+
+void fsi_driver_unregister(struct fsi_driver *fsi_drv)
+{
+	driver_unregister(&fsi_drv->drv);
+}
+EXPORT_SYMBOL_GPL(fsi_driver_unregister);
+
 struct bus_type fsi_bus_type = {
 	.name		= "fsi",
 	.match		= fsi_bus_match,
diff --git a/include/linux/fsi.h b/include/linux/fsi.h
index 66bce48..34f1e9a 100644
--- a/include/linux/fsi.h
+++ b/include/linux/fsi.h
@@ -54,6 +54,18 @@ struct fsi_driver {
 #define to_fsi_dev(devp) container_of(devp, struct fsi_device, dev)
 #define to_fsi_drv(drvp) container_of(drvp, struct fsi_driver, drv)
 
+extern int fsi_driver_register(struct fsi_driver *fsi_drv);
+extern void fsi_driver_unregister(struct fsi_driver *fsi_drv);
+
+/* module_fsi_driver() - Helper macro for drivers that don't do
+ * anything special in module init/exit.  This eliminates a lot of
+ * boilerplate.  Each module may only use this macro once, and
+ * calling it replaces module_init() and module_exit()
+ */
+#define module_fsi_driver(__fsi_driver) \
+		module_driver(__fsi_driver, fsi_driver_register, \
+				fsi_driver_unregister)
+
 extern struct bus_type fsi_bus_type;
 
 #endif /* LINUX_FSI_H */
-- 
1.8.2.2

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#1612207 — [PATCH v4 14/23] drivers/fsi: Add sysfs files for FSI master & slave accesses

From: Jeremy Kerr <jk@ozlabs.org>

This change adds a 'raw' file for reads & writes, and a 'term' file for
the TERM command, and a 'break' file for issuing a BREAK.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Chris Bostic <cbostic@linux.net.ibm.com>
---
 drivers/fsi/fsi-core.c | 116 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 116 insertions(+)

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index 4359e26..f0f0556 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -294,6 +294,95 @@ static int fsi_slave_scan(struct fsi_slave *slave)
 	return 0;
 }
 
+static ssize_t fsi_slave_sysfs_raw_read(struct file *file,
+		struct kobject *kobj, struct bin_attribute *attr, char *buf,
+		loff_t off, size_t count)
+{
+	struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));
+	size_t total_len, read_len;
+	int rc;
+
+	if (off < 0)
+		return -EINVAL;
+
+	if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
+		return -EINVAL;
+
+	for (total_len = 0; total_len < count; total_len += read_len) {
+		read_len = min_t(size_t, count, 4);
+		read_len -= off & 0x3;
+
+		rc = fsi_slave_read(slave, off, buf + total_len, read_len);
+		if (rc)
+			return rc;
+
+		off += read_len;
+	}
+
+	return count;
+}
+
+static ssize_t fsi_slave_sysfs_raw_write(struct file *file,
+		struct kobject *kobj, struct bin_attribute *attr,
+		char *buf, loff_t off, size_t count)
+{
+	struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));
+	size_t total_len, write_len;
+	int rc;
+
+	if (off < 0)
+		return -EINVAL;
+
+	if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
+		return -EINVAL;
+
+	for (total_len = 0; total_len < count; total_len += write_len) {
+		write_len = min_t(size_t, count, 4);
+		write_len -= off & 0x3;
+
+		rc = fsi_slave_write(slave, off, buf + total_len, write_len);
+		if (rc)
+			return rc;
+
+		off += write_len;
+	}
+
+	return count;
+}
+
+static struct bin_attribute fsi_slave_raw_attr = {
+	.attr = {
+		.name = "raw",
+		.mode = 0600,
+	},
+	.size = 0,
+	.read = fsi_slave_sysfs_raw_read,
+	.write = fsi_slave_sysfs_raw_write,
+};
+
+static ssize_t fsi_slave_sysfs_term_write(struct file *file,
+		struct kobject *kobj, struct bin_attribute *attr,
+		char *buf, loff_t off, size_t count)
+{
+	struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));
+	struct fsi_master *master = slave->master;
+
+	if (!master->term)
+		return -ENODEV;
+
+	master->term(master, slave->link, slave->id);
+	return count;
+}
+
+static struct bin_attribute fsi_slave_term_attr = {
+	.attr = {
+		.name = "term",
+		.mode = 0200,
+	},
+	.size = 0,
+	.write = fsi_slave_sysfs_term_write,
+};
+
 /* Encode slave local bus echo delay */
 static inline uint32_t fsi_smode_echodly(int x)
 {
@@ -409,6 +498,14 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
 		return rc;
 	}
 
+	rc = device_create_bin_file(&slave->dev, &fsi_slave_raw_attr);
+	if (rc)
+		dev_warn(&slave->dev, "failed to create raw attr: %d\n", rc);
+
+	rc = device_create_bin_file(&slave->dev, &fsi_slave_term_attr);
+	if (rc)
+		dev_warn(&slave->dev, "failed to create term attr: %d\n", rc);
+
 	fsi_slave_scan(slave);
 	return 0;
 }
@@ -523,6 +620,18 @@ static ssize_t master_rescan_store(struct device *dev,
 
 static DEVICE_ATTR(rescan, 0200, NULL, master_rescan_store);
 
+static ssize_t master_break_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct fsi_master *master = to_fsi_master(dev);
+
+	fsi_master_break(master, 0);
+
+	return count;
+}
+
+static DEVICE_ATTR(break, 0200, NULL, master_break_store);
+
 int fsi_master_register(struct fsi_master *master)
 {
 	int rc;
@@ -546,6 +655,13 @@ int fsi_master_register(struct fsi_master *master)
 		return rc;
 	}
 
+	rc = device_create_file(&master->dev, &dev_attr_break);
+	if (rc) {
+		device_unregister(&master->dev);
+		ida_simple_remove(&master_ida, master->idx);
+		return rc;
+	}
+
 	fsi_master_scan(master);
 
 	return 0;
-- 
1.8.2.2

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#1612208 — [PATCH v4 15/23] drivers/fsi: expose direct-access slave API

From: Jeremy Kerr <jk@ozlabs.org>

Allow drivers to access the slave address ranges.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
---
 drivers/fsi/fsi-core.c | 26 ++++++++++++++++++++------
 include/linux/fsi.h    | 12 ++++++++++++
 2 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index f0f0556..f7e55e7 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -76,10 +76,6 @@ static int fsi_master_read(struct fsi_master *master, int link,
 		uint8_t slave_id, uint32_t addr, void *val, size_t size);
 static int fsi_master_write(struct fsi_master *master, int link,
 		uint8_t slave_id, uint32_t addr, const void *val, size_t size);
-static int fsi_slave_read(struct fsi_slave *slave, uint32_t addr,
-		void *val, size_t size);
-static int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
-		const void *val, size_t size);
 
 /* FSI endpoint-device support */
 
@@ -181,7 +177,7 @@ static int fsi_slave_calc_addr(struct fsi_slave *slave, uint32_t *addrp,
 	return 0;
 }
 
-static int fsi_slave_read(struct fsi_slave *slave, uint32_t addr,
+int fsi_slave_read(struct fsi_slave *slave, uint32_t addr,
 			void *val, size_t size)
 {
 	uint8_t id = slave->id;
@@ -195,7 +191,7 @@ static int fsi_slave_read(struct fsi_slave *slave, uint32_t addr,
 			addr, val, size);
 }
 
-static int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
+int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
 			const void *val, size_t size)
 {
 	uint8_t id = slave->id;
@@ -209,6 +205,24 @@ static int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
 			addr, val, size);
 }
 
+extern int fsi_slave_claim_range(struct fsi_slave *slave,
+		uint32_t addr, uint32_t size)
+{
+	if (addr + size < addr)
+		return -EINVAL;
+
+	if (addr + size > slave->size)
+		return -EINVAL;
+
+	/* todo: check for overlapping claims */
+	return 0;
+}
+
+extern void fsi_slave_release_range(struct fsi_slave *slave,
+		uint32_t addr, uint32_t size)
+{
+}
+
 static int fsi_slave_scan(struct fsi_slave *slave)
 {
 	uint32_t engine_addr;
diff --git a/include/linux/fsi.h b/include/linux/fsi.h
index 34f1e9a..141fd38 100644
--- a/include/linux/fsi.h
+++ b/include/linux/fsi.h
@@ -66,6 +66,18 @@ struct fsi_driver {
 		module_driver(__fsi_driver, fsi_driver_register, \
 				fsi_driver_unregister)
 
+/* direct slave API */
+extern int fsi_slave_claim_range(struct fsi_slave *slave,
+		uint32_t addr, uint32_t size);
+extern void fsi_slave_release_range(struct fsi_slave *slave,
+		uint32_t addr, uint32_t size);
+extern int fsi_slave_read(struct fsi_slave *slave, uint32_t addr,
+		void *val, size_t size);
+extern int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
+		const void *val, size_t size);
+
+
+
 extern struct bus_type fsi_bus_type;
 
 #endif /* LINUX_FSI_H */
-- 
1.8.2.2

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#1612210 — [PATCH v4 04/23] drivers/fsi: Add crc4 helpers

From: Jeremy Kerr <jk@ozlabs.org>

Add some helpers for the crc checks for the slave configuration table.
This works 4-bits-at-a-time, using a simple table approach.

We will need this in the FSI core code, as well as any master
implementations that need to calculate CRCs in software.

We add this to the fsi code (rather than lib/), as we need a specific
polynomial for FSI CRCs.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
 drivers/fsi/fsi-core.c   | 24 ++++++++++++++++++++++++
 drivers/fsi/fsi-master.h | 21 +++++++++++++++++++++
 2 files changed, 45 insertions(+)

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index e90d45d..4bbca95 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -32,6 +32,30 @@ struct fsi_slave {
 
 #define to_fsi_slave(d) container_of(d, struct fsi_slave, dev)
 
+/* crc helpers */
+static const uint8_t crc4_tab[] = {
+	0x0, 0x7, 0xe, 0x9, 0xb, 0xc, 0x5, 0x2,
+	0x1, 0x6, 0xf, 0x8, 0xa, 0xd, 0x4, 0x3,
+};
+
+uint8_t fsi_crc4(uint8_t c, uint64_t x, int bits)
+{
+	int i;
+
+	/* Align to 4-bits */
+	bits = (bits + 3) & ~0x3;
+
+	/* mask off anything above the top bit */
+	x &= (1ull << bits) - 1;
+
+	/* Calculate crc4 over four-bit nibbles, starting at the MSbit */
+	for (i = bits - 4; i >= 0; i -= 4)
+		c = crc4_tab[c ^ ((x >> i) & 0xf)];
+
+	return c;
+}
+EXPORT_SYMBOL_GPL(fsi_crc4);
+
 /* FSI slave support */
 static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
 {
diff --git a/drivers/fsi/fsi-master.h b/drivers/fsi/fsi-master.h
index 7764b00..d6a4885 100644
--- a/drivers/fsi/fsi-master.h
+++ b/drivers/fsi/fsi-master.h
@@ -38,4 +38,25 @@ struct fsi_master {
 extern int fsi_master_register(struct fsi_master *master);
 extern void fsi_master_unregister(struct fsi_master *master);
 
+/**
+ * crc4 helper: Given a starting crc4 state @c, calculate the crc4 vaue of @x,
+ * which is @bits in length. This may be required by master implementations
+ * that do not provide their own hardware checksums.
+ *
+ * The crc4 is performed on 4-bit chunks (which is all we need for FSI
+ * calculations). Typically, we'll want a starting state of 0:
+ *
+ *  c = fsi_crc4(0, msg, len);
+ *
+ * To crc4 a message that includes a single start bit, initialise crc4 state
+ * with:
+ *
+ *  c = fsi_crc4(0, 1, 1);
+ *
+ * Then update with message data:
+ *
+ *  c = fsi_crc4(c, msg, len);
+ */
+uint8_t fsi_crc4(uint8_t c, uint64_t x, int bits);
+
 #endif /* DRIVERS_FSI_MASTER_H */
-- 
1.8.2.2

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#1612212 — [PATCH v4 02/23] drivers/fsi: Add slave definition

From: Jeremy Kerr <jk@ozlabs.org>

Add the initial fsi slave device, which is private to the core code.
This will be a child of the master, and parent to endpoint devices.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
 drivers/fsi/fsi-core.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index ca02913..2f19509 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -22,6 +22,16 @@
 
 static DEFINE_IDA(master_ida);
 
+struct fsi_slave {
+	struct device		dev;
+	struct fsi_master	*master;
+	int			id;
+	int			link;
+	uint32_t		size;	/* size of slave address space */
+};
+
+#define to_fsi_slave(d) container_of(d, struct fsi_slave, dev)
+
 /* FSI master support */
 int fsi_master_register(struct fsi_master *master)
 {
-- 
1.8.2.2

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#1612213 — [PATCH v4 08/23] drivers/fsi: Set slave SMODE to init communication

From: Chris Bostic <cbostic@linux.vnet.ibm.com>

Set CFAM to appropriate ID so that the controlling master can manage
link memory ranges.  Add slave engine register definitions.

Includes changes from Jeremy Kerr <jk@ozlabs.org>.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
 drivers/fsi/fsi-core.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 75 insertions(+)

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index c705ca2..b7b138b 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -21,6 +21,27 @@
 
 #include "fsi-master.h"
 
+#define FSI_SLAVE_BASE			0x800
+
+/*
+ * FSI slave engine control register offsets
+ */
+#define FSI_SMODE			0x0	/* R/W: Mode register */
+
+/*
+ * SMODE fields
+ */
+#define FSI_SMODE_WSC		0x80000000	/* Warm start done */
+#define FSI_SMODE_ECRC		0x20000000	/* Hw CRC check */
+#define FSI_SMODE_SID_SHIFT	24		/* ID shift */
+#define FSI_SMODE_SID_MASK	3		/* ID Mask */
+#define FSI_SMODE_ED_SHIFT	20		/* Echo delay shift */
+#define FSI_SMODE_ED_MASK	0xf		/* Echo delay mask */
+#define FSI_SMODE_SD_SHIFT	16		/* Send delay shift */
+#define FSI_SMODE_SD_MASK	0xf		/* Send delay mask */
+#define FSI_SMODE_LBCRR_SHIFT	8		/* Clk ratio shift */
+#define FSI_SMODE_LBCRR_MASK	0xf		/* Clk ratio mask */
+
 #define FSI_SLAVE_SIZE_23b		0x800000
 
 static DEFINE_IDA(master_ida);
@@ -117,6 +138,52 @@ static int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
 			addr, val, size);
 }
 
+/* Encode slave local bus echo delay */
+static inline uint32_t fsi_smode_echodly(int x)
+{
+	return (x & FSI_SMODE_ED_MASK) << FSI_SMODE_ED_SHIFT;
+}
+
+/* Encode slave local bus send delay */
+static inline uint32_t fsi_smode_senddly(int x)
+{
+	return (x & FSI_SMODE_SD_MASK) << FSI_SMODE_SD_SHIFT;
+}
+
+/* Encode slave local bus clock rate ratio */
+static inline uint32_t fsi_smode_lbcrr(int x)
+{
+	return (x & FSI_SMODE_LBCRR_MASK) << FSI_SMODE_LBCRR_SHIFT;
+}
+
+/* Encode slave ID */
+static inline uint32_t fsi_smode_sid(int x)
+{
+	return (x & FSI_SMODE_SID_MASK) << FSI_SMODE_SID_SHIFT;
+}
+
+static const uint32_t fsi_slave_smode(int id)
+{
+	return FSI_SMODE_WSC | FSI_SMODE_ECRC
+		| fsi_smode_sid(id)
+		| fsi_smode_echodly(0xf) | fsi_smode_senddly(0xf)
+		| fsi_smode_lbcrr(0x8);
+}
+
+static int fsi_slave_set_smode(struct fsi_master *master, int link, int id)
+{
+	uint32_t smode;
+
+	/* set our smode register with the slave ID field to 0; this enables
+	 * extended slave addressing
+	 */
+	smode = fsi_slave_smode(id);
+	smode = cpu_to_be32(smode);
+
+	return fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SMODE,
+			&smode, sizeof(smode));
+}
+
 static void fsi_slave_release(struct device *dev)
 {
 	struct fsi_slave *slave = to_fsi_slave(dev);
@@ -155,6 +222,14 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
 	dev_info(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n",
 			chip_id, master->idx, link, id);
 
+	rc = fsi_slave_set_smode(master, link, id);
+	if (rc) {
+		dev_warn(&master->dev,
+				"can't set smode on slave:%02x:%02x %d\n",
+				link, id, rc);
+		return -ENODEV;
+	}
+
 	/* We can communicate with a slave; create the slave device and
 	 * register.
 	 */
-- 
1.8.2.2

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#1612215 — [PATCH v4 03/23] drivers/fsi: Add empty master scan

From: Jeremy Kerr <jk@ozlabs.org>

When a new fsi master is added, we will need to scan its links, and
slaves attached to those links. This change introduces a little shell to
iterate the links, which we will populate with the actual slave scan in
a later change.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
 drivers/fsi/fsi-core.c | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index 2f19509..e90d45d 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -32,7 +32,25 @@ struct fsi_slave {
 
 #define to_fsi_slave(d) container_of(d, struct fsi_slave, dev)
 
+/* FSI slave support */
+static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
+{
+	/* todo: initialise slave device, perform engine scan */
+
+	return -ENODEV;
+}
+
 /* FSI master support */
+static int fsi_master_scan(struct fsi_master *master)
+{
+	int link;
+
+	for (link = 0; link < master->n_links; link++)
+		fsi_slave_init(master, link, 0);
+
+	return 0;
+}
+
 int fsi_master_register(struct fsi_master *master)
 {
 	int rc;
@@ -44,10 +62,13 @@ int fsi_master_register(struct fsi_master *master)
 	dev_set_name(&master->dev, "fsi%d", master->idx);
 
 	rc = device_register(&master->dev);
-	if (rc)
+	if (rc) {
 		ida_simple_remove(&master_ida, master->idx);
+		return rc;
+	}
 
-	return rc;
+	fsi_master_scan(master);
+	return 0;
 }
 EXPORT_SYMBOL_GPL(fsi_master_register);
 
-- 
1.8.2.2

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