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Commit 7b0ed334 authored by Benjamin Tissoires's avatar Benjamin Tissoires Committed by Wolfram Sang
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i2c: i801: add support of Host Notify 

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: default avatarAndrew Duggan <aduggan@synaptics.com>
Signed-off-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 97d34ec1

drivers/i2c/busses/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -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

drivers/i2c/busses/i2c-i801.c

+85 −3
Original line number Diff line number Diff line
@@ -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
@@ -181,6 +187,12 @@ 
#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)
@@ -256,13 +268,17 @@ 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)
@@ -273,6 +289,7 @@ static const char *i801_feature_names[] = { 
	"Block process call",

	"I2C block read",

	"Interrupt",

	"SMBus Host Notify",

};



static unsigned int disable_features;
@@ -281,7 +298,8 @@ 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. */
@@ -560,8 +578,23 @@ 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
@@ -573,6 +606,8 @@ 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)

{
@@ -585,6 +620,12 @@ 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);
@@ -896,7 +937,28 @@ 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 = {
@@ -1428,6 +1490,7 @@ 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:
@@ -1447,6 +1510,8 @@ 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:
@@ -1556,6 +1621,15 @@ 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);
@@ -1602,6 +1676,14 @@ 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