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@xxxxxxxxxxxxx> Acked-by: Wolfram Sang <wsa@xxxxxxxxxxxxx> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
