[PATCH v9 1/2] i2c: i801: add support of Host Notify

[PATCH v9 1/2] i2c: i801: add support of Host Notify

[Benjamin Tissoires]

The i801 chip can handle the Host Notify feature since ICH 3 as mentioned
in http://www.intel.com/content/dam/doc/datasheet/82801ca-io-controller-hub-3-datasheet.pdf

Enable the functionality unconditionally and propagate the alert
on each notification.

With a T440s and a Synaptics touchpad that implements Host Notify, the
payload data is always 0x0000, so I am not sure if the device actually
sends the payload or if there is a problem regarding the implementation.

Tested-by: Andrew Duggan <aduggan@synaptics.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
---
changes in v2:
- removed the description of the Slave functionality support in the chip table
  (the table shows what is supported, not what the hardware is capable of)
- use i2c-smbus to forward the notification
- remove the fifo, and directly retrieve the address and payload in the worker
- do not check for Host Notification is the feature is not enabled
- use inw_p() to read the payload instead of 2 inb_p() calls
- add /* fall-through */ comment
- unconditionally enable Host Notify if the hardware supports it (can be
  disabled by the user)

no changes in v3

changes in v4:
- make use of the new API -> no more worker spawning here
- solved a race between the access of the Host Notify registers and the actual
  I2C transfers.

changes in v5:
- added SKL Host Notify support

changes in v6:
- select I2C_SMBUS in Kconfig to prevent an undefined reference when I2C_I801
  is set to 'Y' while I2C_SMBUS is set to 'M'

no changes in v7

changes in v8:
- reapplied after http://patchwork.ozlabs.org/patch/632768/ and merged the
  conflict (minor conflict in the struct i801_priv).
- removed the .resume hook as upstream changed suspend/resume hooks and there
  is no need in the end to re-enable host notify on resume (tested on Lenovo
  t440 and t450).
- kept Wolfram's Acked-by as the changes were minor

changes in v9:
- re-add the .resume hook. Looks like the Lenovo T440 sometimes forget to
  re-enable Host Notify on resume, so better have it reset for everybody

 drivers/i2c/busses/Kconfig    |  1 +
 drivers/i2c/busses/i2c-i801.c | 88 +++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 86 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index efa3d9b..b4b6cb0 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -91,6 +91,7 @@ config I2C_I801
 	tristate "Intel 82801 (ICH/PCH)"
 	depends on PCI
 	select CHECK_SIGNATURE if X86 && DMI
+	select I2C_SMBUS
 	help
 	  If you say yes to this option, support will be included for the Intel
 	  801 family of mainboard I2C interfaces.  Specifically, the following
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index b436963..312caed 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -72,6 +72,7 @@
  * Block process call transaction	no
  * I2C block read transaction		yes (doesn't use the block buffer)
  * Slave mode				no
+ * SMBus Host Notify			yes
  * Interrupt processing			yes
  *
  * See the file Documentation/i2c/busses/i2c-i801 for details.
@@ -86,6 +87,7 @@
 #include <linux/ioport.h>
 #include <linux/init.h>
 #include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
 #include <linux/acpi.h>
 #include <linux/io.h>
 #include <linux/dmi.h>
@@ -113,6 +115,10 @@
 #define SMBPEC(p)	(8 + (p)->smba)		/* ICH3 and later */
 #define SMBAUXSTS(p)	(12 + (p)->smba)	/* ICH4 and later */
 #define SMBAUXCTL(p)	(13 + (p)->smba)	/* ICH4 and later */
+#define SMBSLVSTS(p)	(16 + (p)->smba)	/* ICH3 and later */
+#define SMBSLVCMD(p)	(17 + (p)->smba)	/* ICH3 and later */
+#define SMBNTFDADD(p)	(20 + (p)->smba)	/* ICH3 and later */
+#define SMBNTFDDAT(p)	(22 + (p)->smba)	/* ICH3 and later */
 
 /* PCI Address Constants */
 #define SMBBAR		4
@@ -177,6 +183,12 @@
 #define SMBHSTSTS_INTR		0x02
 #define SMBHSTSTS_HOST_BUSY	0x01
 
+/* Host Notify Status registers bits */
+#define SMBSLVSTS_HST_NTFY_STS	1
+
+/* Host Notify Command registers bits */
+#define SMBSLVCMD_HST_NTFY_INTREN	0x01
+
 #define STATUS_ERROR_FLAGS	(SMBHSTSTS_FAILED | SMBHSTSTS_BUS_ERR | \
 				 SMBHSTSTS_DEV_ERR)
 
@@ -252,13 +264,17 @@ struct i801_priv {
 	 */
 	bool acpi_reserved;
 	struct mutex acpi_lock;
+	struct smbus_host_notify *host_notify;
 };
 
+#define SMBHSTNTFY_SIZE		8
+
 #define FEATURE_SMBUS_PEC	(1 << 0)
 #define FEATURE_BLOCK_BUFFER	(1 << 1)
 #define FEATURE_BLOCK_PROC	(1 << 2)
 #define FEATURE_I2C_BLOCK_READ	(1 << 3)
 #define FEATURE_IRQ		(1 << 4)
+#define FEATURE_HOST_NOTIFY	(1 << 5)
 /* Not really a feature, but it's convenient to handle it as such */
 #define FEATURE_IDF		(1 << 15)
 #define FEATURE_TCO		(1 << 16)
@@ -269,6 +285,7 @@ static const char *i801_feature_names[] = {
 	"Block process call",
 	"I2C block read",
 	"Interrupt",
+	"SMBus Host Notify",
 };
 
 static unsigned int disable_features;
@@ -277,7 +294,8 @@ MODULE_PARM_DESC(disable_features, "Disable selected driver features:\n"
 	"\t\t  0x01  disable SMBus PEC\n"
 	"\t\t  0x02  disable the block buffer\n"
 	"\t\t  0x08  disable the I2C block read functionality\n"
-	"\t\t  0x10  don't use interrupts ");
+	"\t\t  0x10  don't use interrupts\n"
+	"\t\t  0x20  disable SMBus Host Notify ");
 
 /* Make sure the SMBus host is ready to start transmitting.
    Return 0 if it is, -EBUSY if it is not. */
@@ -511,8 +529,23 @@ static void i801_isr_byte_done(struct i801_priv *priv)
 	outb_p(SMBHSTSTS_BYTE_DONE, SMBHSTSTS(priv));
 }
 
+static irqreturn_t i801_host_notify_isr(struct i801_priv *priv)
+{
+	unsigned short addr;
+	unsigned int data;
+
+	addr = inb_p(SMBNTFDADD(priv)) >> 1;
+	data = inw_p(SMBNTFDDAT(priv));
+
+	i2c_handle_smbus_host_notify(priv->host_notify, addr, data);
+
+	/* clear Host Notify bit and return */
+	outb_p(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv));
+	return IRQ_HANDLED;
+}
+
 /*
- * There are two kinds of interrupts:
+ * There are three kinds of interrupts:
  *
  * 1) i801 signals transaction completion with one of these interrupts:
  *      INTR - Success
@@ -524,6 +557,8 @@ static void i801_isr_byte_done(struct i801_priv *priv)
  *
  * 2) For byte-by-byte (I2C read/write) transactions, one BYTE_DONE interrupt
  *    occurs for each byte of a byte-by-byte to prepare the next byte.
+ *
+ * 3) Host Notify interrupts
  */
 static irqreturn_t i801_isr(int irq, void *dev_id)
 {
@@ -536,6 +571,12 @@ static irqreturn_t i801_isr(int irq, void *dev_id)
 	if (!(pcists & SMBPCISTS_INTS))
 		return IRQ_NONE;
 
+	if (priv->features & FEATURE_HOST_NOTIFY) {
+		status = inb_p(SMBSLVSTS(priv));
+		if (status & SMBSLVSTS_HST_NTFY_STS)
+			return i801_host_notify_isr(priv);
+	}
+
 	status = inb_p(SMBHSTSTS(priv));
 	if (status & SMBHSTSTS_BYTE_DONE)
 		i801_isr_byte_done(priv);
@@ -847,7 +888,28 @@ static u32 i801_func(struct i2c_adapter *adapter)
 	       I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_WRITE_I2C_BLOCK |
 	       ((priv->features & FEATURE_SMBUS_PEC) ? I2C_FUNC_SMBUS_PEC : 0) |
 	       ((priv->features & FEATURE_I2C_BLOCK_READ) ?
-		I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0);
+		I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0) |
+	       ((priv->features & FEATURE_HOST_NOTIFY) ?
+		I2C_FUNC_SMBUS_HOST_NOTIFY : 0);
+}
+
+static int i801_enable_host_notify(struct i2c_adapter *adapter)
+{
+	struct i801_priv *priv = i2c_get_adapdata(adapter);
+
+	if (!(priv->features & FEATURE_HOST_NOTIFY))
+		return -ENOTSUPP;
+
+	if (!priv->host_notify)
+		priv->host_notify = i2c_setup_smbus_host_notify(adapter);
+	if (!priv->host_notify)
+		return -ENOMEM;
+
+	outb_p(SMBSLVCMD_HST_NTFY_INTREN, SMBSLVCMD(priv));
+	/* clear Host Notify bit to allow a new notification */
+	outb_p(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv));
+
+	return 0;
 }
 
 static const struct i2c_algorithm smbus_algorithm = {
@@ -1379,6 +1441,7 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
 		priv->features |= FEATURE_SMBUS_PEC;
 		priv->features |= FEATURE_BLOCK_BUFFER;
 		priv->features |= FEATURE_TCO;
+		priv->features |= FEATURE_HOST_NOTIFY;
 		break;
 
 	case PCI_DEVICE_ID_INTEL_PATSBURG_SMBUS_IDF0:
@@ -1398,6 +1461,8 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
 		priv->features |= FEATURE_BLOCK_BUFFER;
 		/* fall through */
 	case PCI_DEVICE_ID_INTEL_82801CA_3:
+		priv->features |= FEATURE_HOST_NOTIFY;
+		/* fall through */
 	case PCI_DEVICE_ID_INTEL_82801BA_2:
 	case PCI_DEVICE_ID_INTEL_82801AB_3:
 	case PCI_DEVICE_ID_INTEL_82801AA_3:
@@ -1507,6 +1572,15 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
 		return err;
 	}
 
+	/*
+	 * Enable Host Notify for chips that supports it.
+	 * It is done after i2c_add_adapter() so that we are sure the work queue
+	 * is not used if i2c_add_adapter() fails.
+	 */
+	err = i801_enable_host_notify(&priv->adapter);
+	if (err && err != -ENOTSUPP)
+		dev_warn(&dev->dev, "Unable to enable SMBus Host Notify\n");
+
 	i801_probe_optional_slaves(priv);
 	/* We ignore errors - multiplexing is optional */
 	i801_add_mux(priv);
@@ -1553,6 +1627,14 @@ static int i801_suspend(struct device *dev)
 
 static int i801_resume(struct device *dev)
 {
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct i801_priv *priv = pci_get_drvdata(pci_dev);
+	int err;
+
+	err = i801_enable_host_notify(&priv->adapter);
+	if (err && err != -ENOTSUPP)
+		dev_warn(dev, "Unable to enable SMBus Host Notify\n");
+
 	return 0;
 }
 #endif
-- 
2.5.5

[PATCH v9 2/2] Input: synaptics-rmi4 - add SMBus support

[Benjamin Tissoires]

Code obtained from https://raw.githubusercontent.com/mightybigcar/synaptics-rmi4/jf/drivers/input/rmi4/rmi_smbus.c
and updated to match upstream. And fixed to make it work.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Andrew Duggan <aduggan@synaptics.com>
---

new in v5

no changes in v6

changes in v7:
- fixed typos as per Andrew's requests
- changed module author from Allie to Andrew as per Andrew's request
- add suspend/resume callbacks to match upstream rmi4 behavior

no changes in v8

changes in v8:
- fixes from Dmitry: __le16, __maybe_unused and removed forward declaration

 drivers/input/rmi4/Kconfig     |  12 ++
 drivers/input/rmi4/Makefile    |   1 +
 drivers/input/rmi4/rmi_bus.h   |  12 ++
 drivers/input/rmi4/rmi_smbus.c | 464 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 489 insertions(+)
 create mode 100644 drivers/input/rmi4/rmi_smbus.c

diff --git a/drivers/input/rmi4/Kconfig b/drivers/input/rmi4/Kconfig
index f73df24..86a180b 100644
--- a/drivers/input/rmi4/Kconfig
+++ b/drivers/input/rmi4/Kconfig
@@ -27,6 +27,18 @@ config RMI4_SPI
 
 	  If unsure, say N.
 
+config RMI4_SMB
+	tristate "RMI4 SMB Support"
+	depends on RMI4_CORE && I2C
+	help
+	  Say Y here if you want to support RMI4 devices connected to an SMB
+	  bus.
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called rmi_smbus.
+
 config RMI4_2D_SENSOR
 	bool
 	depends on RMI4_CORE
diff --git a/drivers/input/rmi4/Makefile b/drivers/input/rmi4/Makefile
index 95c00a7..3c8ebf2 100644
--- a/drivers/input/rmi4/Makefile
+++ b/drivers/input/rmi4/Makefile
@@ -11,3 +11,4 @@ rmi_core-$(CONFIG_RMI4_F30) += rmi_f30.o
 # Transports
 obj-$(CONFIG_RMI4_I2C) += rmi_i2c.o
 obj-$(CONFIG_RMI4_SPI) += rmi_spi.o
+obj-$(CONFIG_RMI4_SMB) += rmi_smbus.o
diff --git a/drivers/input/rmi4/rmi_bus.h b/drivers/input/rmi4/rmi_bus.h
index 8995798..b7625a9 100644
--- a/drivers/input/rmi4/rmi_bus.h
+++ b/drivers/input/rmi4/rmi_bus.h
@@ -105,6 +105,18 @@ rmi_get_platform_data(struct rmi_device *d)
 bool rmi_is_physical_device(struct device *dev);
 
 /**
+ * rmi_reset - reset a RMI4 device
+ * @d: Pointer to an RMI device
+ *
+ * Calls for a reset of each function implemented by a specific device.
+ * Returns 0 on success or a negative error code.
+ */
+static inline int rmi_reset(struct rmi_device *d)
+{
+	return d->driver->reset_handler(d);
+}
+
+/**
  * rmi_read - read a single byte
  * @d: Pointer to an RMI device
  * @addr: The address to read from
diff --git a/drivers/input/rmi4/rmi_smbus.c b/drivers/input/rmi4/rmi_smbus.c
new file mode 100644
index 0000000..92c6ab1
--- /dev/null
+++ b/drivers/input/rmi4/rmi_smbus.c
@@ -0,0 +1,464 @@
+/*
+ * Copyright (c) 2015 - 2016 Red Hat, Inc
+ * Copyright (c) 2011, 2012 Synaptics Incorporated
+ * Copyright (c) 2011 Unixphere
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/kconfig.h>
+#include <linux/lockdep.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/rmi.h>
+#include <linux/slab.h>
+#include "rmi_driver.h"
+
+#define SMB_PROTOCOL_VERSION_ADDRESS	0xfd
+#define SMB_MAX_COUNT			32
+#define RMI_SMB2_MAP_SIZE		8 /* 8 entry of 4 bytes each */
+#define RMI_SMB2_MAP_FLAGS_WE		0x01
+
+struct mapping_table_entry {
+	__le16 rmiaddr;
+	u8 readcount;
+	u8 flags;
+};
+
+struct rmi_smb_xport {
+	struct rmi_transport_dev xport;
+	struct i2c_client *client;
+
+	struct mutex page_mutex;
+	int page;
+	u8 table_index;
+	struct mutex mappingtable_mutex;
+	struct mapping_table_entry mapping_table[RMI_SMB2_MAP_SIZE];
+};
+
+static int rmi_smb_get_version(struct rmi_smb_xport *rmi_smb)
+{
+	struct i2c_client *client = rmi_smb->client;
+	int retval;
+
+	/* Check if for SMBus new version device by reading version byte. */
+	retval = i2c_smbus_read_byte_data(client, SMB_PROTOCOL_VERSION_ADDRESS);
+	if (retval < 0) {
+		dev_err(&client->dev, "failed to get SMBus version number!\n");
+		return retval;
+	}
+	return retval + 1;
+}
+
+/* SMB block write - wrapper over ic2_smb_write_block */
+static int smb_block_write(struct rmi_transport_dev *xport,
+			      u8 commandcode, const void *buf, size_t len)
+{
+	struct rmi_smb_xport *rmi_smb =
+		container_of(xport, struct rmi_smb_xport, xport);
+	struct i2c_client *client = rmi_smb->client;
+	int retval;
+
+	retval = i2c_smbus_write_block_data(client, commandcode, len, buf);
+
+	rmi_dbg(RMI_DEBUG_XPORT, &client->dev,
+		"wrote %zd bytes at %#04x: %d (%*ph)\n",
+		len, commandcode, retval, (int)len, buf);
+
+	return retval;
+}
+
+/*
+ * The function to get command code for smbus operations and keeps
+ * records to the driver mapping table
+ */
+static int rmi_smb_get_command_code(struct rmi_transport_dev *xport,
+		u16 rmiaddr, int bytecount, bool isread, u8 *commandcode)
+{
+	struct rmi_smb_xport *rmi_smb =
+		container_of(xport, struct rmi_smb_xport, xport);
+	int i;
+	int retval;
+	struct mapping_table_entry mapping_data[1];
+
+	mutex_lock(&rmi_smb->mappingtable_mutex);
+	for (i = 0; i < RMI_SMB2_MAP_SIZE; i++) {
+		if (rmi_smb->mapping_table[i].rmiaddr == rmiaddr) {
+			if (isread) {
+				if (rmi_smb->mapping_table[i].readcount
+							== bytecount) {
+					*commandcode = i;
+					retval = 0;
+					goto exit;
+				}
+			} else {
+				if (rmi_smb->mapping_table[i].flags &
+							RMI_SMB2_MAP_FLAGS_WE) {
+					*commandcode = i;
+					retval = 0;
+					goto exit;
+				}
+			}
+		}
+	}
+	i = rmi_smb->table_index;
+	rmi_smb->table_index = (i + 1) % RMI_SMB2_MAP_SIZE;
+
+	/* constructs mapping table data entry. 4 bytes each entry */
+	memset(mapping_data, 0, sizeof(mapping_data));
+
+	mapping_data[0].rmiaddr = cpu_to_le16(rmiaddr);
+	mapping_data[0].readcount = bytecount;
+	mapping_data[0].flags = !isread ? RMI_SMB2_MAP_FLAGS_WE : 0;
+
+	retval = smb_block_write(xport, i + 0x80, mapping_data,
+				 sizeof(mapping_data));
+
+	if (retval < 0) {
+		/*
+		 * if not written to device mapping table
+		 * clear the driver mapping table records
+		 */
+		rmi_smb->mapping_table[i].rmiaddr = 0x0000;
+		rmi_smb->mapping_table[i].readcount = 0;
+		rmi_smb->mapping_table[i].flags = 0;
+		goto exit;
+	}
+	/* save to the driver level mapping table */
+	rmi_smb->mapping_table[i].rmiaddr = rmiaddr;
+	rmi_smb->mapping_table[i].readcount = bytecount;
+	rmi_smb->mapping_table[i].flags = !isread ? RMI_SMB2_MAP_FLAGS_WE : 0;
+	*commandcode = i;
+
+exit:
+	mutex_unlock(&rmi_smb->mappingtable_mutex);
+
+	return retval;
+}
+
+static int rmi_smb_write_block(struct rmi_transport_dev *xport, u16 rmiaddr,
+				const void *databuff, size_t len)
+{
+	int retval = 0;
+	u8 commandcode;
+	struct rmi_smb_xport *rmi_smb =
+		container_of(xport, struct rmi_smb_xport, xport);
+	int cur_len = (int)len;
+
+	mutex_lock(&rmi_smb->page_mutex);
+
+	while (cur_len > 0) {
+		/*
+		 * break into 32 bytes chunks to write get command code
+		 */
+		int block_len = min_t(int, len, SMB_MAX_COUNT);
+
+		retval = rmi_smb_get_command_code(xport, rmiaddr, block_len,
+						  false, &commandcode);
+		if (retval < 0)
+			goto exit;
+
+		retval = smb_block_write(xport, commandcode,
+					 databuff, block_len);
+		if (retval < 0)
+			goto exit;
+
+		/* prepare to write next block of bytes */
+		cur_len -= SMB_MAX_COUNT;
+		databuff += SMB_MAX_COUNT;
+		rmiaddr += SMB_MAX_COUNT;
+	}
+exit:
+	mutex_unlock(&rmi_smb->page_mutex);
+	return retval;
+}
+
+/* SMB block read - wrapper over ic2_smb_read_block */
+static int smb_block_read(struct rmi_transport_dev *xport,
+			     u8 commandcode, void *buf, size_t len)
+{
+	struct rmi_smb_xport *rmi_smb =
+		container_of(xport, struct rmi_smb_xport, xport);
+	struct i2c_client *client = rmi_smb->client;
+	int retval;
+
+	retval = i2c_smbus_read_block_data(client, commandcode, buf);
+	if (retval < 0)
+		return retval;
+
+	return retval;
+}
+
+static int rmi_smb_read_block(struct rmi_transport_dev *xport, u16 rmiaddr,
+			      void *databuff, size_t len)
+{
+	struct rmi_smb_xport *rmi_smb =
+		container_of(xport, struct rmi_smb_xport, xport);
+	int retval;
+	u8 commandcode;
+	int cur_len = (int)len;
+
+	mutex_lock(&rmi_smb->page_mutex);
+	memset(databuff, 0, len);
+
+	while (cur_len > 0) {
+		/* break into 32 bytes chunks to write get command code */
+		int block_len =  min_t(int, cur_len, SMB_MAX_COUNT);
+
+		retval = rmi_smb_get_command_code(xport, rmiaddr, block_len,
+						  true, &commandcode);
+		if (retval < 0)
+			goto exit;
+
+		retval = smb_block_read(xport, commandcode,
+					databuff, block_len);
+		if (retval < 0)
+			goto exit;
+
+		/* prepare to read next block of bytes */
+		cur_len -= SMB_MAX_COUNT;
+		databuff += SMB_MAX_COUNT;
+		rmiaddr += SMB_MAX_COUNT;
+	}
+
+	retval = 0;
+
+exit:
+	mutex_unlock(&rmi_smb->page_mutex);
+	return retval;
+}
+
+static void rmi_smb_clear_state(struct rmi_smb_xport *rmi_smb)
+{
+	/* the mapping table has been flushed, discard the current one */
+	mutex_lock(&rmi_smb->mappingtable_mutex);
+	memset(rmi_smb->mapping_table, 0, sizeof(rmi_smb->mapping_table));
+	mutex_unlock(&rmi_smb->mappingtable_mutex);
+}
+
+static int rmi_smb_enable_smbus_mode(struct rmi_smb_xport *rmi_smb)
+{
+	int retval;
+
+	/* we need to get the smbus version to activate the touchpad */
+	retval = rmi_smb_get_version(rmi_smb);
+	if (retval < 0)
+		return retval;
+
+	return 0;
+}
+
+static int rmi_smb_reset(struct rmi_transport_dev *xport, u16 reset_addr)
+{
+	struct rmi_smb_xport *rmi_smb =
+		container_of(xport, struct rmi_smb_xport, xport);
+
+	rmi_smb_clear_state(rmi_smb);
+
+	/*
+	 * we do not call the actual reset command, it has to be handled in
+	 * PS/2 or there will be races between PS/2 and SMBus.
+	 * PS/2 should ensure that a psmouse_reset is called before
+	 * intializing the device and after it has been removed to be in a known
+	 * state.
+	 */
+	return rmi_smb_enable_smbus_mode(rmi_smb);
+}
+
+static const struct rmi_transport_ops rmi_smb_ops = {
+	.write_block	= rmi_smb_write_block,
+	.read_block	= rmi_smb_read_block,
+	.reset		= rmi_smb_reset,
+};
+
+static void rmi_smb_alert(struct i2c_client *client,
+			  enum i2c_alert_protocol type, unsigned int data)
+{
+	struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
+	struct rmi_device *rmi_dev = rmi_smb->xport.rmi_dev;
+	struct rmi_driver_data *drv_data = dev_get_drvdata(&rmi_dev->dev);
+
+	if (type != I2C_PROTOCOL_SMBUS_HOST_NOTIFY)
+		return;
+
+	if (!drv_data) {
+		dev_err(&client->dev,
+			"Something went wrong, driver data is NULL.\n");
+		return;
+	}
+
+	rmi_process_interrupt_requests(rmi_dev);
+}
+
+static int rmi_smb_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct rmi_device_platform_data *pdata = dev_get_platdata(&client->dev);
+	struct rmi_smb_xport *rmi_smb;
+	int retval;
+	int smbus_version;
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_READ_BLOCK_DATA |
+				     I2C_FUNC_SMBUS_HOST_NOTIFY)) {
+		dev_err(&client->dev,
+			"adapter does not support required functionality.\n");
+		return -ENODEV;
+	}
+
+	rmi_smb = devm_kzalloc(&client->dev, sizeof(struct rmi_smb_xport),
+				GFP_KERNEL);
+	if (!rmi_smb)
+		return -ENOMEM;
+
+	if (!pdata) {
+		dev_err(&client->dev, "no platform data, aborting\n");
+		return -ENOMEM;
+	}
+
+	rmi_dbg(RMI_DEBUG_XPORT, &client->dev, "Probing %s.\n",
+		dev_name(&client->dev));
+
+	rmi_smb->client = client;
+	mutex_init(&rmi_smb->page_mutex);
+	mutex_init(&rmi_smb->mappingtable_mutex);
+
+	rmi_smb->xport.dev = &client->dev;
+	rmi_smb->xport.pdata = *pdata;
+	rmi_smb->xport.proto_name = "smb2";
+	rmi_smb->xport.ops = &rmi_smb_ops;
+
+	/* Check if for SMBus new version device by reading version byte. */
+	retval = rmi_smb_get_version(rmi_smb);
+	if (retval < 0)
+		return retval;
+
+	smbus_version = retval;
+	rmi_dbg(RMI_DEBUG_XPORT, &client->dev, "Smbus version is %d",
+		smbus_version);
+
+	if (smbus_version != 2) {
+		dev_err(&client->dev, "Unrecognized SMB version %d.\n",
+				smbus_version);
+		return -ENODEV;
+	}
+
+	i2c_set_clientdata(client, rmi_smb);
+
+	retval = rmi_register_transport_device(&rmi_smb->xport);
+	if (retval) {
+		dev_err(&client->dev, "Failed to register transport driver at 0x%.2X.\n",
+			client->addr);
+		i2c_set_clientdata(client, NULL);
+		return retval;
+	}
+
+	dev_info(&client->dev, "registered rmi smb driver at %#04x.\n",
+			client->addr);
+	return 0;
+
+}
+
+static int rmi_smb_remove(struct i2c_client *client)
+{
+	struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
+
+	rmi_unregister_transport_device(&rmi_smb->xport);
+
+	return 0;
+}
+
+static int __maybe_unused rmi_smb_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
+	int ret;
+
+	ret = rmi_driver_suspend(rmi_smb->xport.rmi_dev);
+	if (ret)
+		dev_warn(dev, "Failed to suspend device: %d\n", ret);
+
+	return ret;
+}
+
+static int __maybe_unused rmi_smb_runtime_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
+	int ret;
+
+	ret = rmi_driver_suspend(rmi_smb->xport.rmi_dev);
+	if (ret)
+		dev_warn(dev, "Failed to suspend device: %d\n", ret);
+
+	return 0;
+}
+
+static int __maybe_unused rmi_smb_runtime_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
+	int ret;
+
+	ret = rmi_driver_resume(rmi_smb->xport.rmi_dev);
+	if (ret)
+		dev_warn(dev, "Failed to resume device: %d\n", ret);
+
+	return 0;
+}
+
+static const struct dev_pm_ops rmi_smb_pm = {
+	SET_SYSTEM_SLEEP_PM_OPS(rmi_smb_suspend, NULL)
+	SET_RUNTIME_PM_OPS(rmi_smb_runtime_suspend, rmi_smb_runtime_resume,
+			   NULL)
+};
+
+static int rmi_smb_resume(struct device *dev)
+{
+	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
+	struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
+	struct rmi_device *rmi_dev = rmi_smb->xport.rmi_dev;
+	int ret;
+
+	rmi_smb_reset(&rmi_smb->xport, 0);
+
+	rmi_reset(rmi_dev);
+
+	ret = rmi_driver_resume(rmi_smb->xport.rmi_dev);
+	if (ret)
+		dev_warn(dev, "Failed to resume device: %d\n", ret);
+
+	return 0;
+}
+
+static const struct i2c_device_id rmi_id[] = {
+	{ "rmi4_smbus", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, rmi_id);
+
+static struct i2c_driver rmi_smb_driver = {
+	.driver = {
+		.owner	= THIS_MODULE,
+		.name	= "rmi4_smbus",
+		.pm	= &rmi_smb_pm,
+		.resume	= rmi_smb_resume,
+	},
+	.id_table	= rmi_id,
+	.probe		= rmi_smb_probe,
+	.remove		= rmi_smb_remove,
+	.alert		= rmi_smb_alert,
+};
+
+module_i2c_driver(rmi_smb_driver);
+
+MODULE_AUTHOR("Andrew Duggan <aduggan@synaptics.com>");
+MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@redhat.com>");
+MODULE_DESCRIPTION("RMI4 SMBus driver");
+MODULE_LICENSE("GPL");
-- 
2.5.5

[PATCH] Input: fix platform_no_drv_owner.cocci warnings

[kbuild test robot]

drivers/input/rmi4/rmi_smbus.c:448:3-8: No need to set .owner here. The core will do it.

 Remove .owner field if calls are used which set it automatically

Generated by: scripts/coccinelle/api/platform_no_drv_owner.cocci

CC: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
---

 rmi_smbus.c |    1 -
 1 file changed, 1 deletion(-)

--- a/drivers/input/rmi4/rmi_smbus.c
+++ b/drivers/input/rmi4/rmi_smbus.c
@@ -445,7 +445,6 @@ MODULE_DEVICE_TABLE(i2c, rmi_id);
 
 static struct i2c_driver rmi_smb_driver = {
 	.driver = {
-		.owner	= THIS_MODULE,
 		.name	= "rmi4_smbus",
 		.pm	= &rmi_smb_pm,
 		.resume	= rmi_smb_resume,

Re: [PATCH v9 2/2] Input: synaptics-rmi4 - add SMBus support

[kbuild test robot]

Hi,

[auto build test WARNING on wsa/i2c/for-next]
[also build test WARNING on v4.7-rc4 next-20160624]
[cannot apply to input/next]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Benjamin-Tissoires/i2c-i801-add-support-of-Host-Notify/20160624-224821
base:   https://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux i2c/for-next


coccinelle warnings: (new ones prefixed by >>)

>> drivers/input/rmi4/rmi_smbus.c:448:3-8: No need to set .owner here. The core will do it.

Please review and possibly fold the followup patch.

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

Re: [PATCH v9 1/2] i2c: i801: add support of Host Notify

[Wolfram Sang]

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On Fri, Jun 24, 2016 at 04:39:49PM +0200, Benjamin Tissoires wrote:
> The i801 chip can handle the Host Notify feature since ICH 3 as mentioned
> in http://www.intel.com/content/dam/doc/datasheet/82801ca-io-controller-hub-3-datasheet.pdf
> 
> Enable the functionality unconditionally and propagate the alert
> on each notification.
> 
> With a T440s and a Synaptics touchpad that implements Host Notify, the
> payload data is always 0x0000, so I am not sure if the device actually
> sends the payload or if there is a problem regarding the implementation.
> 
> Tested-by: Andrew Duggan <aduggan@synaptics.com>
> Acked-by: Wolfram Sang <wsa@the-dreams.de>
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

Applied to for-next, thanks!


[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 819 bytes --]

Re: [PATCH v9 1/2] i2c: i801: add support of Host Notify

[Jean Delvare]

Hi Benjamin,

Once again, sorry for the late review.

On Fri, 24 Jun 2016 16:39:49 +0200, Benjamin Tissoires wrote:
> The i801 chip can handle the Host Notify feature since ICH 3 as mentioned
> in http://www.intel.com/content/dam/doc/datasheet/82801ca-io-controller-hub-3-datasheet.pdf
> 
> Enable the functionality unconditionally and propagate the alert
> on each notification.
> 
> With a T440s and a Synaptics touchpad that implements Host Notify, the
> payload data is always 0x0000, so I am not sure if the device actually
> sends the payload or if there is a problem regarding the implementation.

Out of curiosity, does it work on at least one machine?

> Tested-by: Andrew Duggan <aduggan@synaptics.com>
> Acked-by: Wolfram Sang <wsa@the-dreams.de>
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
> ---
> changes in v2:
> - removed the description of the Slave functionality support in the chip table
>   (the table shows what is supported, not what the hardware is capable of)
> - use i2c-smbus to forward the notification
> - remove the fifo, and directly retrieve the address and payload in the worker
> - do not check for Host Notification is the feature is not enabled
> - use inw_p() to read the payload instead of 2 inb_p() calls
> - add /* fall-through */ comment
> - unconditionally enable Host Notify if the hardware supports it (can be
>   disabled by the user)
> 
> no changes in v3
> 
> changes in v4:
> - make use of the new API -> no more worker spawning here
> - solved a race between the access of the Host Notify registers and the actual
>   I2C transfers.
> 
> changes in v5:
> - added SKL Host Notify support
> 
> changes in v6:
> - select I2C_SMBUS in Kconfig to prevent an undefined reference when I2C_I801
>   is set to 'Y' while I2C_SMBUS is set to 'M'
> 
> no changes in v7
> 
> changes in v8:
> - reapplied after http://patchwork.ozlabs.org/patch/632768/ and merged the
>   conflict (minor conflict in the struct i801_priv).
> - removed the .resume hook as upstream changed suspend/resume hooks and there
>   is no need in the end to re-enable host notify on resume (tested on Lenovo
>   t440 and t450).
> - kept Wolfram's Acked-by as the changes were minor
> 
> changes in v9:
> - re-add the .resume hook. Looks like the Lenovo T440 sometimes forget to
>   re-enable Host Notify on resume, so better have it reset for everybody
> 
>  drivers/i2c/busses/Kconfig    |  1 +
>  drivers/i2c/busses/i2c-i801.c | 88 +++++++++++++++++++++++++++++++++++++++++--
>  2 files changed, 86 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index efa3d9b..b4b6cb0 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -91,6 +91,7 @@ config I2C_I801
>  	tristate "Intel 82801 (ICH/PCH)"
>  	depends on PCI
>  	select CHECK_SIGNATURE if X86 && DMI
> +	select I2C_SMBUS
>  	help
>  	  If you say yes to this option, support will be included for the Intel
>  	  801 family of mainboard I2C interfaces.  Specifically, the following
> diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
> index b436963..312caed 100644
> --- a/drivers/i2c/busses/i2c-i801.c
> +++ b/drivers/i2c/busses/i2c-i801.c
> @@ -72,6 +72,7 @@
>   * Block process call transaction	no
>   * I2C block read transaction		yes (doesn't use the block buffer)
>   * Slave mode				no
> + * SMBus Host Notify			yes
>   * Interrupt processing			yes
>   *
>   * See the file Documentation/i2c/busses/i2c-i801 for details.
> @@ -86,6 +87,7 @@
>  #include <linux/ioport.h>
>  #include <linux/init.h>
>  #include <linux/i2c.h>
> +#include <linux/i2c-smbus.h>
>  #include <linux/acpi.h>
>  #include <linux/io.h>
>  #include <linux/dmi.h>
> @@ -113,6 +115,10 @@
>  #define SMBPEC(p)	(8 + (p)->smba)		/* ICH3 and later */
>  #define SMBAUXSTS(p)	(12 + (p)->smba)	/* ICH4 and later */
>  #define SMBAUXCTL(p)	(13 + (p)->smba)	/* ICH4 and later */
> +#define SMBSLVSTS(p)	(16 + (p)->smba)	/* ICH3 and later */
> +#define SMBSLVCMD(p)	(17 + (p)->smba)	/* ICH3 and later */
> +#define SMBNTFDADD(p)	(20 + (p)->smba)	/* ICH3 and later */
> +#define SMBNTFDDAT(p)	(22 + (p)->smba)	/* ICH3 and later */
>  
>  /* PCI Address Constants */
>  #define SMBBAR		4
> @@ -177,6 +183,12 @@
>  #define SMBHSTSTS_INTR		0x02
>  #define SMBHSTSTS_HOST_BUSY	0x01
>  
> +/* Host Notify Status registers bits */
> +#define SMBSLVSTS_HST_NTFY_STS	1
> +
> +/* Host Notify Command registers bits */
> +#define SMBSLVCMD_HST_NTFY_INTREN	0x01

"register" needs no "s" in these 2 comments. Also it would be nice to
stick to hexadecimal for consistency (I know it's not the case
elsewhere in the driver, but let's not add to it.)

> +
>  #define STATUS_ERROR_FLAGS	(SMBHSTSTS_FAILED | SMBHSTSTS_BUS_ERR | \
>  				 SMBHSTSTS_DEV_ERR)
>  
> @@ -252,13 +264,17 @@ struct i801_priv {
>  	 */
>  	bool acpi_reserved;
>  	struct mutex acpi_lock;
> +	struct smbus_host_notify *host_notify;
>  };
>  
> +#define SMBHSTNTFY_SIZE		8

This constant isn't used anywhere?

> +
>  #define FEATURE_SMBUS_PEC	(1 << 0)
>  #define FEATURE_BLOCK_BUFFER	(1 << 1)
>  #define FEATURE_BLOCK_PROC	(1 << 2)
>  #define FEATURE_I2C_BLOCK_READ	(1 << 3)
>  #define FEATURE_IRQ		(1 << 4)
> +#define FEATURE_HOST_NOTIFY	(1 << 5)
>  /* Not really a feature, but it's convenient to handle it as such */
>  #define FEATURE_IDF		(1 << 15)
>  #define FEATURE_TCO		(1 << 16)
> @@ -269,6 +285,7 @@ static const char *i801_feature_names[] = {
>  	"Block process call",
>  	"I2C block read",
>  	"Interrupt",
> +	"SMBus Host Notify",
>  };
>  
>  static unsigned int disable_features;
> @@ -277,7 +294,8 @@ MODULE_PARM_DESC(disable_features, "Disable selected driver features:\n"
>  	"\t\t  0x01  disable SMBus PEC\n"
>  	"\t\t  0x02  disable the block buffer\n"
>  	"\t\t  0x08  disable the I2C block read functionality\n"
> -	"\t\t  0x10  don't use interrupts ");
> +	"\t\t  0x10  don't use interrupts\n"
> +	"\t\t  0x20  disable SMBus Host Notify ");
>  
>  /* Make sure the SMBus host is ready to start transmitting.
>     Return 0 if it is, -EBUSY if it is not. */
> @@ -511,8 +529,23 @@ static void i801_isr_byte_done(struct i801_priv *priv)
>  	outb_p(SMBHSTSTS_BYTE_DONE, SMBHSTSTS(priv));
>  }
>  
> +static irqreturn_t i801_host_notify_isr(struct i801_priv *priv)
> +{
> +	unsigned short addr;
> +	unsigned int data;
> +
> +	addr = inb_p(SMBNTFDADD(priv)) >> 1;
> +	data = inw_p(SMBNTFDDAT(priv));

The ICH9 datasheet I'm looking at says the data is in 2 8-bit
registers. I wonder if a 16-bit read is OK an all chipsets. Well, if it
isn't we'll learn about it someday, I suppose.

> +
> +	i2c_handle_smbus_host_notify(priv->host_notify, addr, data);

This can fail, in theory. Maybe this should be handled?

> +
> +	/* clear Host Notify bit and return */
> +	outb_p(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv));
> +	return IRQ_HANDLED;
> +}
> +
>  /*
> - * There are two kinds of interrupts:
> + * There are three kinds of interrupts:
>   *
>   * 1) i801 signals transaction completion with one of these interrupts:
>   *      INTR - Success
> @@ -524,6 +557,8 @@ static void i801_isr_byte_done(struct i801_priv *priv)
>   *
>   * 2) For byte-by-byte (I2C read/write) transactions, one BYTE_DONE interrupt
>   *    occurs for each byte of a byte-by-byte to prepare the next byte.
> + *
> + * 3) Host Notify interrupts
>   */
>  static irqreturn_t i801_isr(int irq, void *dev_id)
>  {
> @@ -536,6 +571,12 @@ static irqreturn_t i801_isr(int irq, void *dev_id)
>  	if (!(pcists & SMBPCISTS_INTS))
>  		return IRQ_NONE;
>  
> +	if (priv->features & FEATURE_HOST_NOTIFY) {
> +		status = inb_p(SMBSLVSTS(priv));
> +		if (status & SMBSLVSTS_HST_NTFY_STS)
> +			return i801_host_notify_isr(priv);
> +	}
> +
>  	status = inb_p(SMBHSTSTS(priv));
>  	if (status & SMBHSTSTS_BYTE_DONE)
>  		i801_isr_byte_done(priv);
> @@ -847,7 +888,28 @@ static u32 i801_func(struct i2c_adapter *adapter)
>  	       I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_WRITE_I2C_BLOCK |
>  	       ((priv->features & FEATURE_SMBUS_PEC) ? I2C_FUNC_SMBUS_PEC : 0) |
>  	       ((priv->features & FEATURE_I2C_BLOCK_READ) ?
> -		I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0);
> +		I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0) |
> +	       ((priv->features & FEATURE_HOST_NOTIFY) ?
> +		I2C_FUNC_SMBUS_HOST_NOTIFY : 0);
> +}
> +
> +static int i801_enable_host_notify(struct i2c_adapter *adapter)
> +{
> +	struct i801_priv *priv = i2c_get_adapdata(adapter);
> +
> +	if (!(priv->features & FEATURE_HOST_NOTIFY))
> +		return -ENOTSUPP;

Why do you return an error here? This forces you to special-case it on
further error handling. You could simply return 0 instead, and save
some tests.

> +
> +	if (!priv->host_notify)
> +		priv->host_notify = i2c_setup_smbus_host_notify(adapter);
> +	if (!priv->host_notify)
> +		return -ENOMEM;

Minor optimization: if priv->host_notify was already set, the second
test is not needed.

> +
> +	outb_p(SMBSLVCMD_HST_NTFY_INTREN, SMBSLVCMD(priv));
> +	/* clear Host Notify bit to allow a new notification */
> +	outb_p(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv));
> +
> +	return 0;
>  }
>  
>  static const struct i2c_algorithm smbus_algorithm = {
> @@ -1379,6 +1441,7 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
>  		priv->features |= FEATURE_SMBUS_PEC;
>  		priv->features |= FEATURE_BLOCK_BUFFER;
>  		priv->features |= FEATURE_TCO;
> +		priv->features |= FEATURE_HOST_NOTIFY;
>  		break;
>  
>  	case PCI_DEVICE_ID_INTEL_PATSBURG_SMBUS_IDF0:
> @@ -1398,6 +1461,8 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
>  		priv->features |= FEATURE_BLOCK_BUFFER;
>  		/* fall through */
>  	case PCI_DEVICE_ID_INTEL_82801CA_3:
> +		priv->features |= FEATURE_HOST_NOTIFY;
> +		/* fall through */
>  	case PCI_DEVICE_ID_INTEL_82801BA_2:
>  	case PCI_DEVICE_ID_INTEL_82801AB_3:
>  	case PCI_DEVICE_ID_INTEL_82801AA_3:
> @@ -1507,6 +1572,15 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
>  		return err;
>  	}
>  
> +	/*
> +	 * Enable Host Notify for chips that supports it.
> +	 * It is done after i2c_add_adapter() so that we are sure the work queue
> +	 * is not used if i2c_add_adapter() fails.
> +	 */
> +	err = i801_enable_host_notify(&priv->adapter);
> +	if (err && err != -ENOTSUPP)
> +		dev_warn(&dev->dev, "Unable to enable SMBus Host Notify\n");
> +
>  	i801_probe_optional_slaves(priv);
>  	/* We ignore errors - multiplexing is optional */
>  	i801_add_mux(priv);
> @@ -1553,6 +1627,14 @@ static int i801_suspend(struct device *dev)
>  
>  static int i801_resume(struct device *dev)
>  {
> +	struct pci_dev *pci_dev = to_pci_dev(dev);
> +	struct i801_priv *priv = pci_get_drvdata(pci_dev);
> +	int err;
> +
> +	err = i801_enable_host_notify(&priv->adapter);
> +	if (err && err != -ENOTSUPP)
> +		dev_warn(dev, "Unable to enable SMBus Host Notify\n");
> +
>  	return 0;
>  }
>  #endif


-- 
Jean Delvare
SUSE L3 Support

Re: [PATCH v9 1/2] i2c: i801: add support of Host Notify

[Benjamin Tissoires]

Hi Jean,

On Jul 18 2016 or thereabouts, Jean Delvare wrote:
> Hi Benjamin,
> 
> Once again, sorry for the late review.
> 
> On Fri, 24 Jun 2016 16:39:49 +0200, Benjamin Tissoires wrote:
> > The i801 chip can handle the Host Notify feature since ICH 3 as mentioned
> > in http://www.intel.com/content/dam/doc/datasheet/82801ca-io-controller-hub-3-datasheet.pdf
> > 
> > Enable the functionality unconditionally and propagate the alert
> > on each notification.
> > 
> > With a T440s and a Synaptics touchpad that implements Host Notify, the
> > payload data is always 0x0000, so I am not sure if the device actually
> > sends the payload or if there is a problem regarding the implementation.
> 
> Out of curiosity, does it work on at least one machine?

I have tested the T440, t450 and t460 (3 different generation of Intel
processor), and none seems to be working. The Synaptics touchpad used is
mostly the same, so maybe that's a device issue.

> 
> > Tested-by: Andrew Duggan <aduggan@synaptics.com>
> > Acked-by: Wolfram Sang <wsa@the-dreams.de>
> > Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
> > ---
> > changes in v2:
> > - removed the description of the Slave functionality support in the chip table
> >   (the table shows what is supported, not what the hardware is capable of)
> > - use i2c-smbus to forward the notification
> > - remove the fifo, and directly retrieve the address and payload in the worker
> > - do not check for Host Notification is the feature is not enabled
> > - use inw_p() to read the payload instead of 2 inb_p() calls
> > - add /* fall-through */ comment
> > - unconditionally enable Host Notify if the hardware supports it (can be
> >   disabled by the user)
> > 
> > no changes in v3
> > 
> > changes in v4:
> > - make use of the new API -> no more worker spawning here
> > - solved a race between the access of the Host Notify registers and the actual
> >   I2C transfers.
> > 
> > changes in v5:
> > - added SKL Host Notify support
> > 
> > changes in v6:
> > - select I2C_SMBUS in Kconfig to prevent an undefined reference when I2C_I801
> >   is set to 'Y' while I2C_SMBUS is set to 'M'
> > 
> > no changes in v7
> > 
> > changes in v8:
> > - reapplied after http://patchwork.ozlabs.org/patch/632768/ and merged the
> >   conflict (minor conflict in the struct i801_priv).
> > - removed the .resume hook as upstream changed suspend/resume hooks and there
> >   is no need in the end to re-enable host notify on resume (tested on Lenovo
> >   t440 and t450).
> > - kept Wolfram's Acked-by as the changes were minor
> > 
> > changes in v9:
> > - re-add the .resume hook. Looks like the Lenovo T440 sometimes forget to
> >   re-enable Host Notify on resume, so better have it reset for everybody
> > 
> >  drivers/i2c/busses/Kconfig    |  1 +
> >  drivers/i2c/busses/i2c-i801.c | 88 +++++++++++++++++++++++++++++++++++++++++--
> >  2 files changed, 86 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> > index efa3d9b..b4b6cb0 100644
> > --- a/drivers/i2c/busses/Kconfig
> > +++ b/drivers/i2c/busses/Kconfig
> > @@ -91,6 +91,7 @@ config I2C_I801
> >  	tristate "Intel 82801 (ICH/PCH)"
> >  	depends on PCI
> >  	select CHECK_SIGNATURE if X86 && DMI
> > +	select I2C_SMBUS
> >  	help
> >  	  If you say yes to this option, support will be included for the Intel
> >  	  801 family of mainboard I2C interfaces.  Specifically, the following
> > diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
> > index b436963..312caed 100644
> > --- a/drivers/i2c/busses/i2c-i801.c
> > +++ b/drivers/i2c/busses/i2c-i801.c
> > @@ -72,6 +72,7 @@
> >   * Block process call transaction	no
> >   * I2C block read transaction		yes (doesn't use the block buffer)
> >   * Slave mode				no
> > + * SMBus Host Notify			yes
> >   * Interrupt processing			yes
> >   *
> >   * See the file Documentation/i2c/busses/i2c-i801 for details.
> > @@ -86,6 +87,7 @@
> >  #include <linux/ioport.h>
> >  #include <linux/init.h>
> >  #include <linux/i2c.h>
> > +#include <linux/i2c-smbus.h>
> >  #include <linux/acpi.h>
> >  #include <linux/io.h>
> >  #include <linux/dmi.h>
> > @@ -113,6 +115,10 @@
> >  #define SMBPEC(p)	(8 + (p)->smba)		/* ICH3 and later */
> >  #define SMBAUXSTS(p)	(12 + (p)->smba)	/* ICH4 and later */
> >  #define SMBAUXCTL(p)	(13 + (p)->smba)	/* ICH4 and later */
> > +#define SMBSLVSTS(p)	(16 + (p)->smba)	/* ICH3 and later */
> > +#define SMBSLVCMD(p)	(17 + (p)->smba)	/* ICH3 and later */
> > +#define SMBNTFDADD(p)	(20 + (p)->smba)	/* ICH3 and later */
> > +#define SMBNTFDDAT(p)	(22 + (p)->smba)	/* ICH3 and later */
> >  
> >  /* PCI Address Constants */
> >  #define SMBBAR		4
> > @@ -177,6 +183,12 @@
> >  #define SMBHSTSTS_INTR		0x02
> >  #define SMBHSTSTS_HOST_BUSY	0x01
> >  
> > +/* Host Notify Status registers bits */
> > +#define SMBSLVSTS_HST_NTFY_STS	1
> > +
> > +/* Host Notify Command registers bits */
> > +#define SMBSLVCMD_HST_NTFY_INTREN	0x01
> 
> "register" needs no "s" in these 2 comments. Also it would be nice to
> stick to hexadecimal for consistency (I know it's not the case
> elsewhere in the driver, but let's not add to it.)
> 
> > +
> >  #define STATUS_ERROR_FLAGS	(SMBHSTSTS_FAILED | SMBHSTSTS_BUS_ERR | \
> >  				 SMBHSTSTS_DEV_ERR)
> >  
> > @@ -252,13 +264,17 @@ struct i801_priv {
> >  	 */
> >  	bool acpi_reserved;
> >  	struct mutex acpi_lock;
> > +	struct smbus_host_notify *host_notify;
> >  };
> >  
> > +#define SMBHSTNTFY_SIZE		8
> 
> This constant isn't used anywhere?
> 
> > +
> >  #define FEATURE_SMBUS_PEC	(1 << 0)
> >  #define FEATURE_BLOCK_BUFFER	(1 << 1)
> >  #define FEATURE_BLOCK_PROC	(1 << 2)
> >  #define FEATURE_I2C_BLOCK_READ	(1 << 3)
> >  #define FEATURE_IRQ		(1 << 4)
> > +#define FEATURE_HOST_NOTIFY	(1 << 5)
> >  /* Not really a feature, but it's convenient to handle it as such */
> >  #define FEATURE_IDF		(1 << 15)
> >  #define FEATURE_TCO		(1 << 16)
> > @@ -269,6 +285,7 @@ static const char *i801_feature_names[] = {
> >  	"Block process call",
> >  	"I2C block read",
> >  	"Interrupt",
> > +	"SMBus Host Notify",
> >  };
> >  
> >  static unsigned int disable_features;
> > @@ -277,7 +294,8 @@ MODULE_PARM_DESC(disable_features, "Disable selected driver features:\n"
> >  	"\t\t  0x01  disable SMBus PEC\n"
> >  	"\t\t  0x02  disable the block buffer\n"
> >  	"\t\t  0x08  disable the I2C block read functionality\n"
> > -	"\t\t  0x10  don't use interrupts ");
> > +	"\t\t  0x10  don't use interrupts\n"
> > +	"\t\t  0x20  disable SMBus Host Notify ");
> >  
> >  /* Make sure the SMBus host is ready to start transmitting.
> >     Return 0 if it is, -EBUSY if it is not. */
> > @@ -511,8 +529,23 @@ static void i801_isr_byte_done(struct i801_priv *priv)
> >  	outb_p(SMBHSTSTS_BYTE_DONE, SMBHSTSTS(priv));
> >  }
> >  
> > +static irqreturn_t i801_host_notify_isr(struct i801_priv *priv)
> > +{
> > +	unsigned short addr;
> > +	unsigned int data;
> > +
> > +	addr = inb_p(SMBNTFDADD(priv)) >> 1;
> > +	data = inw_p(SMBNTFDDAT(priv));
> 
> The ICH9 datasheet I'm looking at says the data is in 2 8-bit
> registers. I wonder if a 16-bit read is OK an all chipsets. Well, if it
> isn't we'll learn about it someday, I suppose.

Well, yes, I suppose too :)

I am about to send a series to address all of your remarks. Thanks for
the review!

Cheers,
Benjamin

> 
> > +
> > +	i2c_handle_smbus_host_notify(priv->host_notify, addr, data);
> 
> This can fail, in theory. Maybe this should be handled?
> 
> > +
> > +	/* clear Host Notify bit and return */
> > +	outb_p(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv));
> > +	return IRQ_HANDLED;
> > +}
> > +
> >  /*
> > - * There are two kinds of interrupts:
> > + * There are three kinds of interrupts:
> >   *
> >   * 1) i801 signals transaction completion with one of these interrupts:
> >   *      INTR - Success
> > @@ -524,6 +557,8 @@ static void i801_isr_byte_done(struct i801_priv *priv)
> >   *
> >   * 2) For byte-by-byte (I2C read/write) transactions, one BYTE_DONE interrupt
> >   *    occurs for each byte of a byte-by-byte to prepare the next byte.
> > + *
> > + * 3) Host Notify interrupts
> >   */
> >  static irqreturn_t i801_isr(int irq, void *dev_id)
> >  {
> > @@ -536,6 +571,12 @@ static irqreturn_t i801_isr(int irq, void *dev_id)
> >  	if (!(pcists & SMBPCISTS_INTS))
> >  		return IRQ_NONE;
> >  
> > +	if (priv->features & FEATURE_HOST_NOTIFY) {
> > +		status = inb_p(SMBSLVSTS(priv));
> > +		if (status & SMBSLVSTS_HST_NTFY_STS)
> > +			return i801_host_notify_isr(priv);
> > +	}
> > +
> >  	status = inb_p(SMBHSTSTS(priv));
> >  	if (status & SMBHSTSTS_BYTE_DONE)
> >  		i801_isr_byte_done(priv);
> > @@ -847,7 +888,28 @@ static u32 i801_func(struct i2c_adapter *adapter)
> >  	       I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_WRITE_I2C_BLOCK |
> >  	       ((priv->features & FEATURE_SMBUS_PEC) ? I2C_FUNC_SMBUS_PEC : 0) |
> >  	       ((priv->features & FEATURE_I2C_BLOCK_READ) ?
> > -		I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0);
> > +		I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0) |
> > +	       ((priv->features & FEATURE_HOST_NOTIFY) ?
> > +		I2C_FUNC_SMBUS_HOST_NOTIFY : 0);
> > +}
> > +
> > +static int i801_enable_host_notify(struct i2c_adapter *adapter)
> > +{
> > +	struct i801_priv *priv = i2c_get_adapdata(adapter);
> > +
> > +	if (!(priv->features & FEATURE_HOST_NOTIFY))
> > +		return -ENOTSUPP;
> 
> Why do you return an error here? This forces you to special-case it on
> further error handling. You could simply return 0 instead, and save
> some tests.
> 
> > +
> > +	if (!priv->host_notify)
> > +		priv->host_notify = i2c_setup_smbus_host_notify(adapter);
> > +	if (!priv->host_notify)
> > +		return -ENOMEM;
> 
> Minor optimization: if priv->host_notify was already set, the second
> test is not needed.
> 
> > +
> > +	outb_p(SMBSLVCMD_HST_NTFY_INTREN, SMBSLVCMD(priv));
> > +	/* clear Host Notify bit to allow a new notification */
> > +	outb_p(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv));
> > +
> > +	return 0;
> >  }
> >  
> >  static const struct i2c_algorithm smbus_algorithm = {
> > @@ -1379,6 +1441,7 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
> >  		priv->features |= FEATURE_SMBUS_PEC;
> >  		priv->features |= FEATURE_BLOCK_BUFFER;
> >  		priv->features |= FEATURE_TCO;
> > +		priv->features |= FEATURE_HOST_NOTIFY;
> >  		break;
> >  
> >  	case PCI_DEVICE_ID_INTEL_PATSBURG_SMBUS_IDF0:
> > @@ -1398,6 +1461,8 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
> >  		priv->features |= FEATURE_BLOCK_BUFFER;
> >  		/* fall through */
> >  	case PCI_DEVICE_ID_INTEL_82801CA_3:
> > +		priv->features |= FEATURE_HOST_NOTIFY;
> > +		/* fall through */
> >  	case PCI_DEVICE_ID_INTEL_82801BA_2:
> >  	case PCI_DEVICE_ID_INTEL_82801AB_3:
> >  	case PCI_DEVICE_ID_INTEL_82801AA_3:
> > @@ -1507,6 +1572,15 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
> >  		return err;
> >  	}
> >  
> > +	/*
> > +	 * Enable Host Notify for chips that supports it.
> > +	 * It is done after i2c_add_adapter() so that we are sure the work queue
> > +	 * is not used if i2c_add_adapter() fails.
> > +	 */
> > +	err = i801_enable_host_notify(&priv->adapter);
> > +	if (err && err != -ENOTSUPP)
> > +		dev_warn(&dev->dev, "Unable to enable SMBus Host Notify\n");
> > +
> >  	i801_probe_optional_slaves(priv);
> >  	/* We ignore errors - multiplexing is optional */
> >  	i801_add_mux(priv);
> > @@ -1553,6 +1627,14 @@ static int i801_suspend(struct device *dev)
> >  
> >  static int i801_resume(struct device *dev)
> >  {
> > +	struct pci_dev *pci_dev = to_pci_dev(dev);
> > +	struct i801_priv *priv = pci_get_drvdata(pci_dev);
> > +	int err;
> > +
> > +	err = i801_enable_host_notify(&priv->adapter);
> > +	if (err && err != -ENOTSUPP)
> > +		dev_warn(dev, "Unable to enable SMBus Host Notify\n");
> > +
> >  	return 0;
> >  }
> >  #endif
> 
> 
> -- 
> Jean Delvare
> SUSE L3 Support

Re: [PATCH v9 1/2] i2c: i801: add support of Host Notify

[Jean Delvare]

On Thu, 28 Jul 2016 11:44:57 +0200, Benjamin Tissoires wrote:
> On Jul 18 2016 or thereabouts, Jean Delvare wrote:
> > On Fri, 24 Jun 2016 16:39:49 +0200, Benjamin Tissoires wrote:
> > > The i801 chip can handle the Host Notify feature since ICH 3 as mentioned
> > > in http://www.intel.com/content/dam/doc/datasheet/82801ca-io-controller-hub-3-datasheet.pdf
> > > 
> > > Enable the functionality unconditionally and propagate the alert
> > > on each notification.
> > > 
> > > With a T440s and a Synaptics touchpad that implements Host Notify, the
> > > payload data is always 0x0000, so I am not sure if the device actually
> > > sends the payload or if there is a problem regarding the implementation.
> > 
> > Out of curiosity, does it work on at least one machine?
> 
> I have tested the T440, t450 and t460 (3 different generation of Intel
> processor), and none seems to be working. The Synaptics touchpad used is
> mostly the same, so maybe that's a device issue.

May I ask why you are pushing the code upstream then, if it has no
known (working) user?

-- 
Jean Delvare
SUSE L3 Support

Re: [PATCH v9 1/2] i2c: i801: add support of Host Notify

[Benjamin Tissoires]

On Aug 01 2016 or thereabouts, Jean Delvare wrote:
> On Thu, 28 Jul 2016 11:44:57 +0200, Benjamin Tissoires wrote:
> > On Jul 18 2016 or thereabouts, Jean Delvare wrote:
> > > On Fri, 24 Jun 2016 16:39:49 +0200, Benjamin Tissoires wrote:
> > > > The i801 chip can handle the Host Notify feature since ICH 3 as mentioned
> > > > in http://www.intel.com/content/dam/doc/datasheet/82801ca-io-controller-hub-3-datasheet.pdf
> > > > 
> > > > Enable the functionality unconditionally and propagate the alert
> > > > on each notification.
> > > > 
> > > > With a T440s and a Synaptics touchpad that implements Host Notify, the
> > > > payload data is always 0x0000, so I am not sure if the device actually
> > > > sends the payload or if there is a problem regarding the implementation.
> > > 
> > > Out of curiosity, does it work on at least one machine?
> > 
> > I have tested the T440, t450 and t460 (3 different generation of Intel
> > processor), and none seems to be working. The Synaptics touchpad used is
> > mostly the same, so maybe that's a device issue.
> 
> May I ask why you are pushing the code upstream then, if it has no
> known (working) user?
> 

K. Then I guess I'll just have to remove these reads from the driver.

Cheers,
Benjamin