[PATCH v8 0/8] fsi: Add IBM I2C Responder virtual FSI master

[PATCH v8 0/8] fsi: Add IBM I2C Responder virtual FSI master

[Eddie James]

The I2C Responder (I2CR) is an I2C device that translates I2C commands
to CFAM or SCOM operations, effectively implementing an FSI master and
bus.

Changes since v7:
 - Add FSI master device naming patch
 - Use I2C adapter number as FSI master index with "i2cr" name
 - Export the fsi_master_i2cr_read/write functions for the SCOM driver

Changes since v6:
 - Drop conversions to BE except in the FSI core interface
 - Emulate the CFAM config table since it doesn't exist off the I2CR
 - Drop status check during probe
 - Add release function for device
 - Update SCOM driver with newer interfaces and drop BE conversion
 - New sbefifo change to not check state during probe

Changes since v5:
 - Make I2CR scom driver depend on I2CR FSI master

Changes since v4:
 - Add I2CR scom driver and associated patches
 - Use compatible strings for FSI drivers if specified
 - Include aliased device numbering patch
 - Restructure the trace events to eliminate holes

Changes since v3:
 - Rework the endian-ness in i2cr_write
 - Rework the tracing to include the i2c bus and device address

Changes since v2:
 - Fix the bindings again, sorry for the spam

Changes since v1:
 - Fix the binding document
 - Change the binding name
 - Clean up the size argument checking
 - Reduce __force by using packed struct for the command

Eddie James (8):
  fsi: Move fsi_slave structure definition to header
  fsi: Make master device indexing and naming optional
  dt-bindings: fsi: Document the IBM I2C Responder virtual FSI master
  fsi: Add IBM I2C Responder virtual FSI master
  fsi: Add I2C Responder SCOM driver
  fsi: Add aliased device numbering
  fsi: Use of_match_table for bus matching if specified
  fsi: sbefifo: Don't check status during probe

 .../bindings/fsi/ibm,i2cr-fsi-master.yaml     |  41 +++
 drivers/fsi/Kconfig                           |  17 +
 drivers/fsi/Makefile                          |   2 +
 drivers/fsi/fsi-core.c                        |  73 ++--
 drivers/fsi/fsi-master-aspeed.c               |   2 +-
 drivers/fsi/fsi-master-ast-cf.c               |   2 +-
 drivers/fsi/fsi-master-gpio.c                 |   2 +-
 drivers/fsi/fsi-master-hub.c                  |   2 +-
 drivers/fsi/fsi-master-i2cr.c                 | 318 ++++++++++++++++++
 drivers/fsi/fsi-master-i2cr.h                 |  24 ++
 drivers/fsi/fsi-master.h                      |   3 +-
 drivers/fsi/fsi-sbefifo.c                     |   8 -
 drivers/fsi/fsi-scom.c                        |   8 +
 drivers/fsi/fsi-slave.h                       |  28 ++
 drivers/fsi/i2cr-scom.c                       | 154 +++++++++
 include/trace/events/fsi_master_i2cr.h        | 107 ++++++
 16 files changed, 752 insertions(+), 39 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/fsi/ibm,i2cr-fsi-master.yaml
 create mode 100644 drivers/fsi/fsi-master-i2cr.c
 create mode 100644 drivers/fsi/fsi-master-i2cr.h
 create mode 100644 drivers/fsi/fsi-slave.h
 create mode 100644 drivers/fsi/i2cr-scom.c
 create mode 100644 include/trace/events/fsi_master_i2cr.h

-- 
2.31.1

[PATCH v8 1/8] fsi: Move fsi_slave structure definition to header

[Eddie James]

Some FSI drivers may have need of the slave definition, so
move it to a header file. Also use one macro for obtaining a
pointer to the fsi_master structure.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 drivers/fsi/fsi-core.c          | 24 ++++--------------------
 drivers/fsi/fsi-master-aspeed.c |  2 +-
 drivers/fsi/fsi-master-ast-cf.c |  2 +-
 drivers/fsi/fsi-master-gpio.c   |  2 +-
 drivers/fsi/fsi-master-hub.c    |  2 +-
 drivers/fsi/fsi-master.h        |  2 +-
 drivers/fsi/fsi-slave.h         | 28 ++++++++++++++++++++++++++++
 7 files changed, 37 insertions(+), 25 deletions(-)
 create mode 100644 drivers/fsi/fsi-slave.h

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index 0b927c9f4267..d591e68afd11 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -23,6 +23,10 @@
 #include <linux/uaccess.h>
 
 #include "fsi-master.h"
+#include "fsi-slave.h"
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/fsi.h>
 
 #define FSI_SLAVE_CONF_NEXT_MASK	GENMASK(31, 31)
 #define FSI_SLAVE_CONF_SLOTS_MASK	GENMASK(23, 16)
@@ -78,26 +82,6 @@ static const int engine_page_size = 0x400;
 
 static DEFINE_IDA(master_ida);
 
-struct fsi_slave {
-	struct device		dev;
-	struct fsi_master	*master;
-	struct cdev		cdev;
-	int			cdev_idx;
-	int			id;	/* FSI address */
-	int			link;	/* FSI link# */
-	u32			cfam_id;
-	int			chip_id;
-	uint32_t		size;	/* size of slave address space */
-	u8			t_send_delay;
-	u8			t_echo_delay;
-};
-
-#define CREATE_TRACE_POINTS
-#include <trace/events/fsi.h>
-
-#define to_fsi_master(d) container_of(d, struct fsi_master, dev)
-#define to_fsi_slave(d) container_of(d, struct fsi_slave, dev)
-
 static const int slave_retries = 2;
 static int discard_errors;
 
diff --git a/drivers/fsi/fsi-master-aspeed.c b/drivers/fsi/fsi-master-aspeed.c
index 7cec1772820d..437f87b4a6a3 100644
--- a/drivers/fsi/fsi-master-aspeed.c
+++ b/drivers/fsi/fsi-master-aspeed.c
@@ -376,7 +376,7 @@ static int aspeed_master_break(struct fsi_master *master, int link)
 static void aspeed_master_release(struct device *dev)
 {
 	struct fsi_master_aspeed *aspeed =
-		to_fsi_master_aspeed(dev_to_fsi_master(dev));
+		to_fsi_master_aspeed(to_fsi_master(dev));
 
 	kfree(aspeed);
 }
diff --git a/drivers/fsi/fsi-master-ast-cf.c b/drivers/fsi/fsi-master-ast-cf.c
index 5f608ef8b53c..6124978305eb 100644
--- a/drivers/fsi/fsi-master-ast-cf.c
+++ b/drivers/fsi/fsi-master-ast-cf.c
@@ -1190,7 +1190,7 @@ static int fsi_master_acf_gpio_release(void *data)
 
 static void fsi_master_acf_release(struct device *dev)
 {
-	struct fsi_master_acf *master = to_fsi_master_acf(dev_to_fsi_master(dev));
+	struct fsi_master_acf *master = to_fsi_master_acf(to_fsi_master(dev));
 
 	/* Cleanup, stop coprocessor */
 	mutex_lock(&master->lock);
diff --git a/drivers/fsi/fsi-master-gpio.c b/drivers/fsi/fsi-master-gpio.c
index 7d5f29b4b595..ed03da4f2447 100644
--- a/drivers/fsi/fsi-master-gpio.c
+++ b/drivers/fsi/fsi-master-gpio.c
@@ -761,7 +761,7 @@ static DEVICE_ATTR(external_mode, 0664,
 
 static void fsi_master_gpio_release(struct device *dev)
 {
-	struct fsi_master_gpio *master = to_fsi_master_gpio(dev_to_fsi_master(dev));
+	struct fsi_master_gpio *master = to_fsi_master_gpio(to_fsi_master(dev));
 
 	of_node_put(dev_of_node(master->dev));
 
diff --git a/drivers/fsi/fsi-master-hub.c b/drivers/fsi/fsi-master-hub.c
index 01f0a796111e..6d8b6e8854e5 100644
--- a/drivers/fsi/fsi-master-hub.c
+++ b/drivers/fsi/fsi-master-hub.c
@@ -105,7 +105,7 @@ static int hub_master_link_enable(struct fsi_master *master, int link,
 
 static void hub_master_release(struct device *dev)
 {
-	struct fsi_master_hub *hub = to_fsi_master_hub(dev_to_fsi_master(dev));
+	struct fsi_master_hub *hub = to_fsi_master_hub(to_fsi_master(dev));
 
 	kfree(hub);
 }
diff --git a/drivers/fsi/fsi-master.h b/drivers/fsi/fsi-master.h
index 4762315a46ba..967622c1cabf 100644
--- a/drivers/fsi/fsi-master.h
+++ b/drivers/fsi/fsi-master.h
@@ -136,7 +136,7 @@ struct fsi_master {
 				       u8 t_send_delay, u8 t_echo_delay);
 };
 
-#define dev_to_fsi_master(d) container_of(d, struct fsi_master, dev)
+#define to_fsi_master(d) container_of(d, struct fsi_master, dev)
 
 /**
  * fsi_master registration & lifetime: the fsi_master_register() and
diff --git a/drivers/fsi/fsi-slave.h b/drivers/fsi/fsi-slave.h
new file mode 100644
index 000000000000..1d63a585829d
--- /dev/null
+++ b/drivers/fsi/fsi-slave.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (C) IBM Corporation 2023 */
+
+#ifndef DRIVERS_FSI_SLAVE_H
+#define DRIVERS_FSI_SLAVE_H
+
+#include <linux/cdev.h>
+#include <linux/device.h>
+
+struct fsi_master;
+
+struct fsi_slave {
+	struct device		dev;
+	struct fsi_master	*master;
+	struct cdev		cdev;
+	int			cdev_idx;
+	int			id;	/* FSI address */
+	int			link;	/* FSI link# */
+	u32			cfam_id;
+	int			chip_id;
+	uint32_t		size;	/* size of slave address space */
+	u8			t_send_delay;
+	u8			t_echo_delay;
+};
+
+#define to_fsi_slave(d) container_of(d, struct fsi_slave, dev)
+
+#endif /* DRIVERS_FSI_SLAVE_H */
-- 
2.31.1

[PATCH v8 2/8] fsi: Make master device indexing and naming optional

[Eddie James]

Some FSI masters need different device naming, so make the indexing and naming
an optional part of FSI master registration.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 drivers/fsi/fsi-core.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index d591e68afd11..3271e40702ec 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -1297,11 +1297,16 @@ int fsi_master_register(struct fsi_master *master)
 	struct device_node *np;
 
 	mutex_init(&master->scan_lock);
-	master->idx = ida_simple_get(&master_ida, 0, INT_MAX, GFP_KERNEL);
-	if (master->idx < 0)
-		return master->idx;
 
-	dev_set_name(&master->dev, "fsi%d", master->idx);
+	if (!master->idx) {
+		master->idx = ida_simple_get(&master_ida, 0, INT_MAX,
+					     GFP_KERNEL);
+		if (master->idx < 0)
+			return master->idx;
+
+		dev_set_name(&master->dev, "fsi%d", master->idx);
+	}
+
 	master->dev.class = &fsi_master_class;
 
 	rc = device_register(&master->dev);
-- 
2.31.1

[PATCH v8 3/8] dt-bindings: fsi: Document the IBM I2C Responder virtual FSI master

[Eddie James]

The I2C Responder translates I2C commands to CFAM or SCOM operations,
effectively implementing an FSI master.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 .../bindings/fsi/ibm,i2cr-fsi-master.yaml     | 41 +++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/fsi/ibm,i2cr-fsi-master.yaml

diff --git a/Documentation/devicetree/bindings/fsi/ibm,i2cr-fsi-master.yaml b/Documentation/devicetree/bindings/fsi/ibm,i2cr-fsi-master.yaml
new file mode 100644
index 000000000000..442cecdc57cb
--- /dev/null
+++ b/Documentation/devicetree/bindings/fsi/ibm,i2cr-fsi-master.yaml
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/fsi/ibm,i2cr-fsi-master.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: IBM I2C Responder virtual FSI master
+
+maintainers:
+  - Eddie James <eajames@linux.ibm.com>
+
+description: |
+  The I2C Responder (I2CR) is a an I2C device that's connected to an FSI CFAM
+  (see fsi.txt). The I2CR translates I2C bus operations to FSI CFAM reads and
+  writes or SCOM operations, thereby acting as an FSI master.
+
+properties:
+  compatible:
+    enum:
+      - ibm,i2cr-fsi-master
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      i2cr@20 {
+        compatible = "ibm,i2cr-fsi-master";
+        reg = <0x20>;
+      };
+    };
-- 
2.31.1

[PATCH v8 4/8] fsi: Add IBM I2C Responder virtual FSI master

[Eddie James]

The I2C Responder (I2CR) is an I2C device that translates I2C commands
to CFAM or SCOM operations, effectively implementing an FSI master and
bus.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 drivers/fsi/Kconfig                    |   9 +
 drivers/fsi/Makefile                   |   1 +
 drivers/fsi/fsi-master-i2cr.c          | 318 +++++++++++++++++++++++++
 drivers/fsi/fsi-master-i2cr.h          |  24 ++
 drivers/fsi/fsi-master.h               |   1 +
 include/trace/events/fsi_master_i2cr.h | 107 +++++++++
 6 files changed, 460 insertions(+)
 create mode 100644 drivers/fsi/fsi-master-i2cr.c
 create mode 100644 drivers/fsi/fsi-master-i2cr.h
 create mode 100644 include/trace/events/fsi_master_i2cr.h

diff --git a/drivers/fsi/Kconfig b/drivers/fsi/Kconfig
index e6668a869913..999be82720c5 100644
--- a/drivers/fsi/Kconfig
+++ b/drivers/fsi/Kconfig
@@ -62,6 +62,15 @@ config FSI_MASTER_ASPEED
 
 	 Enable it for your BMC kernel in an OpenPower or IBM Power system.
 
+config FSI_MASTER_I2CR
+	tristate "IBM I2C Responder virtual FSI master"
+	depends on I2C
+	help
+	  This option enables a virtual FSI master in order to access a CFAM
+	  behind an IBM I2C Responder (I2CR) chip. The I2CR is an I2C device
+	  that translates I2C commands to CFAM or SCOM operations, effectively
+	  implementing an FSI master and bus.
+
 config FSI_SCOM
 	tristate "SCOM FSI client device driver"
 	help
diff --git a/drivers/fsi/Makefile b/drivers/fsi/Makefile
index da218a1ad8e1..34dbaa1c452e 100644
--- a/drivers/fsi/Makefile
+++ b/drivers/fsi/Makefile
@@ -4,6 +4,7 @@ obj-$(CONFIG_FSI) += fsi-core.o
 obj-$(CONFIG_FSI_MASTER_HUB) += fsi-master-hub.o
 obj-$(CONFIG_FSI_MASTER_ASPEED) += fsi-master-aspeed.o
 obj-$(CONFIG_FSI_MASTER_GPIO) += fsi-master-gpio.o
+obj-$(CONFIG_FSI_MASTER_I2CR) += fsi-master-i2cr.o
 obj-$(CONFIG_FSI_MASTER_AST_CF) += fsi-master-ast-cf.o
 obj-$(CONFIG_FSI_SCOM) += fsi-scom.o
 obj-$(CONFIG_FSI_SBEFIFO) += fsi-sbefifo.o
diff --git a/drivers/fsi/fsi-master-i2cr.c b/drivers/fsi/fsi-master-i2cr.c
new file mode 100644
index 000000000000..e4e8a5931ca3
--- /dev/null
+++ b/drivers/fsi/fsi-master-i2cr.c
@@ -0,0 +1,318 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) IBM Corporation 2023 */
+
+#include <linux/device.h>
+#include <linux/fsi.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
+
+#include "fsi-master-i2cr.h"
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/fsi_master_i2cr.h>
+
+#define I2CR_ADDRESS_CFAM(a)	((a) >> 2)
+#define I2CR_INITIAL_PARITY	true
+
+#define I2CR_STATUS_CMD		0x60002
+#define  I2CR_STATUS_ERR	 BIT_ULL(61)
+#define I2CR_ERROR_CMD		0x60004
+#define I2CR_LOG_CMD		0x60008
+
+static const u8 i2cr_cfam[] = {
+	0xc0, 0x02, 0x0d, 0xa6,
+	0x80, 0x01, 0x10, 0x02,
+	0x80, 0x01, 0x10, 0x02,
+	0x80, 0x01, 0x10, 0x02,
+	0x80, 0x01, 0x80, 0x52,
+	0x80, 0x01, 0x10, 0x02,
+	0x80, 0x01, 0x10, 0x02,
+	0x80, 0x01, 0x10, 0x02,
+	0x80, 0x01, 0x10, 0x02,
+	0x80, 0x01, 0x22, 0x2d,
+	0x00, 0x00, 0x00, 0x00,
+	0xde, 0xad, 0xc0, 0xde
+};
+
+static bool i2cr_check_parity32(u32 v, bool parity)
+{
+	u32 i;
+
+	for (i = 0; i < 32; ++i) {
+		if (v & (1u << i))
+			parity = !parity;
+	}
+
+	return parity;
+}
+
+static bool i2cr_check_parity64(u64 v)
+{
+	u32 i;
+	bool parity = I2CR_INITIAL_PARITY;
+
+	for (i = 0; i < 64; ++i) {
+		if (v & (1llu << i))
+			parity = !parity;
+	}
+
+	return parity;
+}
+
+static u32 i2cr_get_command(u32 address, bool parity)
+{
+	address <<= 1;
+
+	if (i2cr_check_parity32(address, parity))
+		address |= 1;
+
+	return address;
+}
+
+static int i2cr_transfer(struct i2c_client *client, u32 command, u64 *data)
+{
+	struct i2c_msg msgs[2];
+	int ret;
+
+	msgs[0].addr = client->addr;
+	msgs[0].flags = 0;
+	msgs[0].len = sizeof(command);
+	msgs[0].buf = (__u8 *)&command;
+	msgs[1].addr = client->addr;
+	msgs[1].flags = I2C_M_RD;
+	msgs[1].len = sizeof(*data);
+	msgs[1].buf = (__u8 *)data;
+
+	ret = i2c_transfer(client->adapter, msgs, 2);
+	if (ret == 2)
+		return 0;
+
+	trace_i2cr_i2c_error(client, command, ret);
+
+	if (ret < 0)
+		return ret;
+
+	return -EIO;
+}
+
+static int i2cr_check_status(struct i2c_client *client)
+{
+	u64 status;
+	int ret;
+
+	ret = i2cr_transfer(client, I2CR_STATUS_CMD, &status);
+	if (ret)
+		return ret;
+
+	if (status & I2CR_STATUS_ERR) {
+		u32 buf[3] = { 0, 0, 0 };
+		u64 error;
+		u64 log;
+
+		i2cr_transfer(client, I2CR_ERROR_CMD, &error);
+		i2cr_transfer(client, I2CR_LOG_CMD, &log);
+
+		trace_i2cr_status_error(client, status, error, log);
+
+		buf[0] = I2CR_STATUS_CMD;
+		i2c_master_send(client, (const char *)buf, sizeof(buf));
+
+		buf[0] = I2CR_ERROR_CMD;
+		i2c_master_send(client, (const char *)buf, sizeof(buf));
+
+		buf[0] = I2CR_LOG_CMD;
+		i2c_master_send(client, (const char *)buf, sizeof(buf));
+
+		dev_err(&client->dev, "status:%016llx error:%016llx log:%016llx\n", status, error,
+			log);
+		return -EREMOTEIO;
+	}
+
+	trace_i2cr_status(client, status);
+	return 0;
+}
+
+int fsi_master_i2cr_read(struct fsi_master_i2cr *i2cr, u32 addr, u64 *data)
+{
+	u32 command = i2cr_get_command(addr, I2CR_INITIAL_PARITY);
+	int ret;
+
+	mutex_lock(&i2cr->lock);
+
+	ret = i2cr_transfer(i2cr->client, command, data);
+	if (ret)
+		goto unlock;
+
+	ret = i2cr_check_status(i2cr->client);
+	if (ret)
+		goto unlock;
+
+	trace_i2cr_read(i2cr->client, command, data);
+
+unlock:
+	mutex_unlock(&i2cr->lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(fsi_master_i2cr_read);
+
+int fsi_master_i2cr_write(struct fsi_master_i2cr *i2cr, u32 addr, u64 data)
+{
+	u32 buf[3] = { 0 };
+	int ret;
+
+	buf[0] = i2cr_get_command(addr, i2cr_check_parity64(data));
+	memcpy(&buf[1], &data, sizeof(data));
+
+	mutex_lock(&i2cr->lock);
+
+	ret = i2c_master_send(i2cr->client, (const char *)buf, sizeof(buf));
+	if (ret == sizeof(buf)) {
+		ret = i2cr_check_status(i2cr->client);
+		if (!ret)
+			trace_i2cr_write(i2cr->client, buf[0], data);
+	} else {
+		trace_i2cr_i2c_error(i2cr->client, buf[0], ret);
+
+		if (ret >= 0)
+			ret = -EIO;
+	}
+
+	mutex_unlock(&i2cr->lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(fsi_master_i2cr_write);
+
+static int i2cr_read(struct fsi_master *master, int link, uint8_t id, uint32_t addr, void *val,
+		     size_t size)
+{
+	struct fsi_master_i2cr *i2cr = container_of(master, struct fsi_master_i2cr, master);
+	u64 data;
+	size_t i;
+	int ret;
+
+	if (link || id || (addr & 0xffff0000) || !(size == 1 || size == 2 || size == 4))
+		return -EINVAL;
+
+	/*
+	 * The I2CR doesn't have CFAM or FSI slave address space - only the
+	 * engines. In order for this to work with the FSI core, we need to
+	 * emulate at minimum the CFAM config table so that the appropriate
+	 * engines are discovered.
+	 */
+	if (addr < 0xc00) {
+		if (addr > sizeof(i2cr_cfam) - 4)
+			addr = (addr & 0x3) + (sizeof(i2cr_cfam) - 4);
+
+		memcpy(val, &i2cr_cfam[addr], size);
+		return 0;
+	}
+
+	ret = fsi_master_i2cr_read(i2cr, I2CR_ADDRESS_CFAM(addr), &data);
+	if (ret)
+		return ret;
+
+	/*
+	 * FSI core expects up to 4 bytes BE back, while I2CR replied with LE
+	 * bytes on the wire.
+	 */
+	for (i = 0; i < size; ++i)
+		((u8 *)val)[i] = ((u8 *)&data)[7 - i];
+
+	return 0;
+}
+
+static int i2cr_write(struct fsi_master *master, int link, uint8_t id, uint32_t addr,
+		      const void *val, size_t size)
+{
+	struct fsi_master_i2cr *i2cr = container_of(master, struct fsi_master_i2cr, master);
+	u64 data = 0;
+	size_t i;
+
+	if (link || id || (addr & 0xffff0000) || !(size == 1 || size == 2 || size == 4))
+		return -EINVAL;
+
+	/* I2CR writes to CFAM or FSI slave address are a successful no-op. */
+	if (addr < 0xc00)
+		return 0;
+
+	/*
+	 * FSI core passes up to 4 bytes BE, while the I2CR expects LE bytes on
+	 * the wire.
+	 */
+	for (i = 0; i < size; ++i)
+		((u8 *)&data)[7 - i] = ((u8 *)val)[i];
+
+	return fsi_master_i2cr_write(i2cr, I2CR_ADDRESS_CFAM(addr), data);
+}
+
+static void i2cr_release(struct device *dev)
+{
+	struct fsi_master_i2cr *i2cr = to_fsi_master_i2cr(to_fsi_master(dev));
+
+	of_node_put(dev->of_node);
+
+	kfree(i2cr);
+}
+
+static int i2cr_probe(struct i2c_client *client)
+{
+	struct fsi_master_i2cr *i2cr;
+	int ret;
+
+	i2cr = kzalloc(sizeof(*i2cr), GFP_KERNEL);
+	if (!i2cr)
+		return -ENOMEM;
+
+	/* Only one I2CR on any given I2C bus (fixed I2C device address) */
+	i2cr->master.idx = client->adapter->nr;
+	dev_set_name(&i2cr->master.dev, "i2cr%d",i2cr->master.idx);
+	i2cr->master.dev.parent = &client->dev;
+	i2cr->master.dev.of_node = of_node_get(dev_of_node(&client->dev));
+	i2cr->master.dev.release = i2cr_release;
+
+	i2cr->master.n_links = 1;
+	i2cr->master.flags = FSI_MASTER_FLAG_I2CR;
+	i2cr->master.read = i2cr_read;
+	i2cr->master.write = i2cr_write;
+
+	mutex_init(&i2cr->lock);
+	i2cr->client = client;
+
+	ret = fsi_master_register(&i2cr->master);
+	if (ret)
+		return ret;
+
+	i2c_set_clientdata(client, i2cr);
+	return 0;
+}
+
+static void i2cr_remove(struct i2c_client *client)
+{
+	struct fsi_master_i2cr *i2cr = i2c_get_clientdata(client);
+
+	i2cr->master.idx = -1;
+	fsi_master_unregister(&i2cr->master);
+}
+
+static const struct of_device_id i2cr_ids[] = {
+	{ .compatible = "ibm,i2cr-fsi-master" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, i2cr_ids);
+
+static struct i2c_driver i2cr_driver = {
+	.probe_new = i2cr_probe,
+	.remove = i2cr_remove,
+	.driver = {
+		.name = "fsi-master-i2cr",
+		.of_match_table = i2cr_ids,
+	},
+};
+
+module_i2c_driver(i2cr_driver)
+
+MODULE_AUTHOR("Eddie James <eajames@linux.ibm.com>");
+MODULE_DESCRIPTION("IBM I2C Responder virtual FSI master driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/fsi/fsi-master-i2cr.h b/drivers/fsi/fsi-master-i2cr.h
new file mode 100644
index 000000000000..929d63995c7b
--- /dev/null
+++ b/drivers/fsi/fsi-master-i2cr.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (C) IBM Corporation 2023 */
+
+#ifndef DRIVERS_FSI_MASTER_I2CR_H
+#define DRIVERS_FSI_MASTER_I2CR_H
+
+#include <linux/mutex.h>
+
+#include "fsi-master.h"
+
+struct i2c_client;
+
+struct fsi_master_i2cr {
+	struct fsi_master master;
+	struct mutex lock;	/* protect HW access */
+	struct i2c_client *client;
+};
+
+#define to_fsi_master_i2cr(m)	container_of(m, struct fsi_master_i2cr, master)
+
+int fsi_master_i2cr_read(struct fsi_master_i2cr *i2cr, u32 addr, u64 *data);
+int fsi_master_i2cr_write(struct fsi_master_i2cr *i2cr, u32 addr, u64 data);
+
+#endif /* DRIVERS_FSI_MASTER_I2CR_H */
diff --git a/drivers/fsi/fsi-master.h b/drivers/fsi/fsi-master.h
index 967622c1cabf..a1fa315849d2 100644
--- a/drivers/fsi/fsi-master.h
+++ b/drivers/fsi/fsi-master.h
@@ -111,6 +111,7 @@
 
 /* fsi-master definition and flags */
 #define FSI_MASTER_FLAG_SWCLOCK		0x1
+#define FSI_MASTER_FLAG_I2CR		0x2
 
 /*
  * Structures and function prototypes
diff --git a/include/trace/events/fsi_master_i2cr.h b/include/trace/events/fsi_master_i2cr.h
new file mode 100644
index 000000000000..c33eba130049
--- /dev/null
+++ b/include/trace/events/fsi_master_i2cr.h
@@ -0,0 +1,107 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM fsi_master_i2cr
+
+#if !defined(_TRACE_FSI_MASTER_I2CR_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_FSI_MASTER_I2CR_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(i2cr_i2c_error,
+	TP_PROTO(const struct i2c_client *client, uint32_t command, int rc),
+	TP_ARGS(client, command, rc),
+	TP_STRUCT__entry(
+		__field(int, bus)
+		__field(int, rc)
+		__array(unsigned char, command, sizeof(uint32_t))
+		__field(unsigned short, addr)
+	),
+	TP_fast_assign(
+		__entry->bus = client->adapter->nr;
+		__entry->rc = rc;
+		memcpy(__entry->command, &command, sizeof(uint32_t));
+		__entry->addr = client->addr;
+	),
+	TP_printk("%d-%02x command:{ %*ph } rc:%d", __entry->bus, __entry->addr,
+		  (int)sizeof(uint32_t), __entry->command, __entry->rc)
+);
+
+TRACE_EVENT(i2cr_read,
+	TP_PROTO(const struct i2c_client *client, uint32_t command, uint64_t *data),
+	TP_ARGS(client, command, data),
+	TP_STRUCT__entry(
+		__field(int, bus)
+		__array(unsigned char, data, sizeof(uint64_t))
+		__array(unsigned char, command, sizeof(uint32_t))
+		__field(unsigned short, addr)
+	),
+	TP_fast_assign(
+		__entry->bus = client->adapter->nr;
+		memcpy(__entry->data, data, sizeof(uint64_t));
+		memcpy(__entry->command, &command, sizeof(uint32_t));
+		__entry->addr = client->addr;
+	),
+	TP_printk("%d-%02x command:{ %*ph } { %*ph }", __entry->bus, __entry->addr,
+		  (int)sizeof(uint32_t), __entry->command, (int)sizeof(uint64_t), __entry->data)
+);
+
+TRACE_EVENT(i2cr_status,
+	TP_PROTO(const struct i2c_client *client, uint64_t status),
+	TP_ARGS(client, status),
+	TP_STRUCT__entry(
+		__field(uint64_t, status)
+		__field(int, bus)
+		__field(unsigned short, addr)
+	),
+	TP_fast_assign(
+		__entry->status = status;
+		__entry->bus = client->adapter->nr;
+		__entry->addr = client->addr;
+	),
+	TP_printk("%d-%02x %016llx", __entry->bus, __entry->addr, __entry->status)
+);
+
+TRACE_EVENT(i2cr_status_error,
+	TP_PROTO(const struct i2c_client *client, uint64_t status, uint64_t error, uint64_t log),
+	TP_ARGS(client, status, error, log),
+	TP_STRUCT__entry(
+		__field(uint64_t, error)
+		__field(uint64_t, log)
+		__field(uint64_t, status)
+		__field(int, bus)
+		__field(unsigned short, addr)
+	),
+	TP_fast_assign(
+		__entry->error = error;
+		__entry->log = log;
+		__entry->status = status;
+		__entry->bus = client->adapter->nr;
+		__entry->addr = client->addr;
+	),
+	TP_printk("%d-%02x status:%016llx error:%016llx log:%016llx", __entry->bus, __entry->addr,
+		  __entry->status, __entry->error, __entry->log)
+);
+
+TRACE_EVENT(i2cr_write,
+	TP_PROTO(const struct i2c_client *client, uint32_t command, uint64_t data),
+	TP_ARGS(client, command, data),
+	TP_STRUCT__entry(
+		__field(int, bus)
+		__array(unsigned char, data, sizeof(uint64_t))
+		__array(unsigned char, command, sizeof(uint32_t))
+		__field(unsigned short, addr)
+	),
+	TP_fast_assign(
+		__entry->bus = client->adapter->nr;
+		memcpy(__entry->data, &data, sizeof(uint64_t));
+		memcpy(__entry->command, &command, sizeof(uint32_t));
+		__entry->addr = client->addr;
+	),
+	TP_printk("%d-%02x command:{ %*ph } { %*ph }", __entry->bus, __entry->addr,
+		  (int)sizeof(uint32_t), __entry->command, (int)sizeof(uint64_t), __entry->data)
+);
+
+#endif
+
+#include <trace/define_trace.h>
-- 
2.31.1

[PATCH v8 5/8] fsi: Add I2C Responder SCOM driver

[Eddie James]

The I2CR has the capability to directly perform SCOM operations,
circumventing the need to drive the FSI2PIB engine. Add a new
driver to perform SCOM operations through the I2CR.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 drivers/fsi/Kconfig     |   8 +++
 drivers/fsi/Makefile    |   1 +
 drivers/fsi/i2cr-scom.c | 154 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 163 insertions(+)
 create mode 100644 drivers/fsi/i2cr-scom.c

diff --git a/drivers/fsi/Kconfig b/drivers/fsi/Kconfig
index 999be82720c5..79a31593618a 100644
--- a/drivers/fsi/Kconfig
+++ b/drivers/fsi/Kconfig
@@ -94,4 +94,12 @@ config FSI_OCC
 	provide the raw sensor data as well as perform thermal and power
 	management on the system.
 
+config I2CR_SCOM
+	tristate "IBM I2C Responder SCOM driver"
+	depends on FSI_MASTER_I2CR
+	help
+	  This option enables an I2C Responder based SCOM device driver. The
+	  I2CR has the capability to directly perform SCOM operations instead
+	  of using the FSI2PIB engine.
+
 endif
diff --git a/drivers/fsi/Makefile b/drivers/fsi/Makefile
index 34dbaa1c452e..5550aa15e0b1 100644
--- a/drivers/fsi/Makefile
+++ b/drivers/fsi/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_FSI_MASTER_AST_CF) += fsi-master-ast-cf.o
 obj-$(CONFIG_FSI_SCOM) += fsi-scom.o
 obj-$(CONFIG_FSI_SBEFIFO) += fsi-sbefifo.o
 obj-$(CONFIG_FSI_OCC) += fsi-occ.o
+obj-$(CONFIG_I2CR_SCOM) += i2cr-scom.o
diff --git a/drivers/fsi/i2cr-scom.c b/drivers/fsi/i2cr-scom.c
new file mode 100644
index 000000000000..63b548bdef3e
--- /dev/null
+++ b/drivers/fsi/i2cr-scom.c
@@ -0,0 +1,154 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) IBM Corporation 2023 */
+
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/fsi.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+
+#include "fsi-master-i2cr.h"
+#include "fsi-slave.h"
+
+struct i2cr_scom {
+	struct device dev;
+	struct cdev cdev;
+	struct fsi_master_i2cr *i2cr;
+};
+
+static loff_t i2cr_scom_llseek(struct file *file, loff_t offset, int whence)
+{
+	switch (whence) {
+	case SEEK_CUR:
+		break;
+	case SEEK_SET:
+		file->f_pos = offset;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return offset;
+}
+
+static ssize_t i2cr_scom_read(struct file *filep, char __user *buf, size_t len, loff_t *offset)
+{
+	struct i2cr_scom *scom = filep->private_data;
+	u64 data;
+	int ret;
+
+	if (len != sizeof(data))
+		return -EINVAL;
+
+	ret = fsi_master_i2cr_read(scom->i2cr, (u32)*offset, &data);
+	if (ret)
+		return ret;
+
+	ret = copy_to_user(buf, &data, len);
+	if (ret)
+		return ret;
+
+	return len;
+}
+
+static ssize_t i2cr_scom_write(struct file *filep, const char __user *buf, size_t len,
+			       loff_t *offset)
+{
+	struct i2cr_scom *scom = filep->private_data;
+	u64 data;
+	int ret;
+
+	if (len != sizeof(data))
+		return -EINVAL;
+
+	ret = copy_from_user(&data, buf, len);
+	if (ret)
+		return ret;
+
+	ret = fsi_master_i2cr_write(scom->i2cr, (u32)*offset, data);
+	if (ret)
+		return ret;
+
+	return len;
+}
+
+static const struct file_operations i2cr_scom_fops = {
+	.owner		= THIS_MODULE,
+	.open		= simple_open,
+	.llseek		= i2cr_scom_llseek,
+	.read		= i2cr_scom_read,
+	.write		= i2cr_scom_write,
+};
+
+static int i2cr_scom_probe(struct device *dev)
+{
+	struct fsi_device *fsi_dev = to_fsi_dev(dev);
+	struct i2cr_scom *scom;
+	int didx;
+	int ret;
+
+	if (!(fsi_dev->slave->master->flags & FSI_MASTER_FLAG_I2CR))
+		return -ENODEV;
+
+	scom = devm_kzalloc(dev, sizeof(*scom), GFP_KERNEL);
+	if (!scom)
+		return -ENOMEM;
+
+	scom->i2cr = to_fsi_master_i2cr(fsi_dev->slave->master);
+	dev_set_drvdata(dev, scom);
+
+	scom->dev.type = &fsi_cdev_type;
+	scom->dev.parent = dev;
+	device_initialize(&scom->dev);
+
+	ret = fsi_get_new_minor(fsi_dev, fsi_dev_scom, &scom->dev.devt, &didx);
+	if (ret)
+		return ret;
+
+	dev_set_name(&scom->dev, "scom%d", didx);
+	cdev_init(&scom->cdev, &i2cr_scom_fops);
+	ret = cdev_device_add(&scom->cdev, &scom->dev);
+	if (ret)
+		fsi_free_minor(scom->dev.devt);
+
+	return ret;
+}
+
+static int i2cr_scom_remove(struct device *dev)
+{
+	struct i2cr_scom *scom = dev_get_drvdata(dev);
+
+	cdev_device_del(&scom->cdev, &scom->dev);
+	fsi_free_minor(scom->dev.devt);
+
+	return 0;
+}
+
+static const struct of_device_id i2cr_scom_of_ids[] = {
+	{ .compatible = "ibm,i2cr-scom" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, i2cr_scom_of_ids);
+
+static const struct fsi_device_id i2cr_scom_ids[] = {
+	{ 0x5, FSI_VERSION_ANY },
+	{ }
+};
+
+static struct fsi_driver i2cr_scom_driver = {
+	.id_table = i2cr_scom_ids,
+	.drv = {
+		.name = "i2cr_scom",
+		.bus = &fsi_bus_type,
+		.of_match_table = i2cr_scom_of_ids,
+		.probe = i2cr_scom_probe,
+		.remove = i2cr_scom_remove,
+	}
+};
+
+module_fsi_driver(i2cr_scom_driver);
+
+MODULE_AUTHOR("Eddie James <eajames@linux.ibm.com>");
+MODULE_DESCRIPTION("IBM I2C Responder SCOM driver");
+MODULE_LICENSE("GPL");
-- 
2.31.1

[PATCH v8 6/8] fsi: Add aliased device numbering

[Eddie James]

The I2C and SPI subsystems can use an aliased name to number the device.
Add similar support to the FSI subsystem for any device type.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 drivers/fsi/fsi-core.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index 3271e40702ec..48f25dc0fad7 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -955,9 +955,34 @@ static int __fsi_get_new_minor(struct fsi_slave *slave, enum fsi_dev_type type,
 	return 0;
 }
 
+static const char *const fsi_dev_type_names[] = {
+	"cfam",
+	"sbefifo",
+	"scom",
+	"occ",
+};
+
 int fsi_get_new_minor(struct fsi_device *fdev, enum fsi_dev_type type,
 		      dev_t *out_dev, int *out_index)
 {
+	if (fdev->dev.of_node) {
+		int aid = of_alias_get_id(fdev->dev.of_node, fsi_dev_type_names[type]);
+
+		if (aid >= 0) {
+			int id = (aid << 4) | type;
+
+			id = ida_simple_get(&fsi_minor_ida, id, id + 1, GFP_KERNEL);
+			if (id >= 0) {
+				*out_index = aid;
+				*out_dev = fsi_base_dev + id;
+				return 0;
+			}
+
+			if (id != -ENOSPC)
+				return id;
+		}
+	}
+
 	return __fsi_get_new_minor(fdev->slave, type, out_dev, out_index);
 }
 EXPORT_SYMBOL_GPL(fsi_get_new_minor);
-- 
2.31.1

[PATCH v8 7/8] fsi: Use of_match_table for bus matching if specified

[Eddie James]

Since we have two scom drivers, use the standard of matching if
the driver specifies a table so that the right devices go to the
right driver.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 drivers/fsi/fsi-core.c | 11 +++++++++--
 drivers/fsi/fsi-scom.c |  8 ++++++++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index 48f25dc0fad7..5191f6979346 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -16,6 +16,7 @@
 #include <linux/idr.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/slab.h>
 #include <linux/bitops.h>
 #include <linux/cdev.h>
@@ -1380,8 +1381,14 @@ static int fsi_bus_match(struct device *dev, struct device_driver *drv)
 		if (id->engine_type != fsi_dev->engine_type)
 			continue;
 		if (id->version == FSI_VERSION_ANY ||
-				id->version == fsi_dev->version)
-			return 1;
+		    id->version == fsi_dev->version) {
+			if (drv->of_match_table) {
+				if (of_driver_match_device(dev, drv))
+					return 1;
+			} else {
+				return 1;
+			}
+		}
 	}
 
 	return 0;
diff --git a/drivers/fsi/fsi-scom.c b/drivers/fsi/fsi-scom.c
index bcb756dc9866..61dbda9dbe2b 100644
--- a/drivers/fsi/fsi-scom.c
+++ b/drivers/fsi/fsi-scom.c
@@ -10,6 +10,7 @@
 #include <linux/cdev.h>
 #include <linux/delay.h>
 #include <linux/fs.h>
+#include <linux/mod_devicetable.h>
 #include <linux/uaccess.h>
 #include <linux/slab.h>
 #include <linux/list.h>
@@ -587,6 +588,12 @@ static int scom_remove(struct device *dev)
 	return 0;
 }
 
+static const struct of_device_id scom_of_ids[] = {
+	{ .compatible = "ibm,fsi2pib" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, scom_of_ids);
+
 static const struct fsi_device_id scom_ids[] = {
 	{
 		.engine_type = FSI_ENGID_SCOM,
@@ -600,6 +607,7 @@ static struct fsi_driver scom_drv = {
 	.drv = {
 		.name = "scom",
 		.bus = &fsi_bus_type,
+		.of_match_table = scom_of_ids,
 		.probe = scom_probe,
 		.remove = scom_remove,
 	}
-- 
2.31.1

[PATCH v8 8/8] fsi: sbefifo: Don't check status during probe

[Eddie James]

The status check during probe doesn't serve any purpose. Any attempt
to use the SBEFIFO will result in the same check and cleanup.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 drivers/fsi/fsi-sbefifo.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/drivers/fsi/fsi-sbefifo.c b/drivers/fsi/fsi-sbefifo.c
index 9912b7a6a4b9..42d7c95528d1 100644
--- a/drivers/fsi/fsi-sbefifo.c
+++ b/drivers/fsi/fsi-sbefifo.c
@@ -1027,14 +1027,6 @@ static int sbefifo_probe(struct device *dev)
 	mutex_init(&sbefifo->lock);
 	sbefifo->timeout_start_rsp_ms = SBEFIFO_TIMEOUT_START_RSP;
 
-	/*
-	 * Try cleaning up the FIFO. If this fails, we still register the
-	 * driver and will try cleaning things up again on the next access.
-	 */
-	rc = sbefifo_cleanup_hw(sbefifo);
-	if (rc && rc != -ESHUTDOWN)
-		dev_err(dev, "Initial HW cleanup failed, will retry later\n");
-
 	/* Create chardev for userspace access */
 	sbefifo->dev.type = &fsi_cdev_type;
 	sbefifo->dev.parent = dev;
-- 
2.31.1