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i2c: i801: add support of Host Notify

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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>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Benjamin Tissoires 2016-06-24 16:39:49 +02:00 committed by Wolfram Sang
parent 97d34ec136
commit 7b0ed334b8
2 changed files with 86 additions and 3 deletions
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1
drivers/i2c/busses/Kconfig
View File

@ -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

88
drivers/i2c/busses/i2c-i801.c
View File

@ -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