Merge branch 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging

* 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
  i2c: Document the message size limit
  i2c-algo-pca: Drop duplicate variable
  i2c: Hook up runtime PM support
  i2c-parport-light: Add SMBus alert support
  i2c-parport: Add SMBus alert support
  i2c: Separate Kconfig option for i2c-smbus
  i2c: Add SMBus alert support
  i2c-parport: Give powered devices some time to settle
  i2c-tiny-usb: Fix a comment on bus frequency
  i2c-i801: Add Intel Cougar Point device IDs
  i2c: Make PCI device ids constant

Documentation/i2c/busses/i2c-i801

@@ -15,7 +15,8 @@ Supported adapters:
   * Intel 82801I (ICH9)
   * Intel EP80579 (Tolapai)
   * Intel 82801JI (ICH10)
-  * Intel PCH
+  * Intel 3400/5 Series (PCH)
+  * Intel Cougar Point (PCH)
    Datasheets: Publicly available at the Intel website
 
 Authors: 

Documentation/i2c/busses/i2c-parport

@@ -29,6 +29,9 @@ can be easily added when needed.
 Earlier kernels defaulted to type=0 (Philips).  But now, if the type
 parameter is missing, the driver will simply fail to initialize.
 
+SMBus alert support is available on adapters which have this line properly
+connected to the parallel port's interrupt pin.
+
 
 Building your own adapter
 -------------------------

Documentation/i2c/busses/i2c-parport-light

@@ -9,3 +9,14 @@ parport handling is not an option. The drawback is a reduced portability
 and the impossibility to daisy-chain other parallel port devices.                 
   
 Please see i2c-parport for documentation.
+
+Module parameters:
+
+* type: type of adapter (see i2c-parport or modinfo)
+
+* base: base I/O address
+  Default is 0x378 which is fairly common for parallel ports, at least on PC.
+
+* irq: optional IRQ
+  This must be passed if you want SMBus alert support, assuming your adapter
+  actually supports this.

Documentation/i2c/smbus-protocol

@@ -185,6 +185,22 @@ the protocol. All ARP communications use slave address 0x61 and
 require PEC checksums.
 
 
+SMBus Alert
+===========
+
+SMBus Alert was introduced in Revision 1.0 of the specification.
+
+The SMBus alert protocol allows several SMBus slave devices to share a
+single interrupt pin on the SMBus master, while still allowing the master
+to know which slave triggered the interrupt.
+
+This is implemented the following way in the Linux kernel:
+* I2C bus drivers which support SMBus alert should call
+  i2c_setup_smbus_alert() to setup SMBus alert support.
+* I2C drivers for devices which can trigger SMBus alerts should implement
+  the optional alert() callback.
+
+
 I2C Block Transactions
 ======================
 

Documentation/i2c/writing-clients

@@ -318,8 +318,9 @@ Plain I2C communication
 These routines read and write some bytes from/to a client. The client
 contains the i2c address, so you do not have to include it. The second
 parameter contains the bytes to read/write, the third the number of bytes
-to read/write (must be less than the length of the buffer.) Returned is
-the actual number of bytes read/written.
+to read/write (must be less than the length of the buffer, also should be
+less than 64k since msg.len is u16.) Returned is the actual number of bytes
+read/written.
 
 	int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msg,
 			 int num);

drivers/i2c/Kconfig

@@ -61,6 +61,16 @@ config I2C_HELPER_AUTO
 
 	  In doubt, say Y.
 
+config I2C_SMBUS
+	tristate "SMBus-specific protocols" if !I2C_HELPER_AUTO
+	help
+	  Say Y here if you want support for SMBus extensions to the I2C
+	  specification. At the moment, the only supported extension is
+	  the SMBus alert protocol.
+
+	  This support is also available as a module.  If so, the module
+	  will be called i2c-smbus.
+
 source drivers/i2c/algos/Kconfig
 source drivers/i2c/busses/Kconfig
 source drivers/i2c/chips/Kconfig

drivers/i2c/Makefile

@@ -4,6 +4,7 @@
 
 obj-$(CONFIG_I2C_BOARDINFO)	+= i2c-boardinfo.o
 obj-$(CONFIG_I2C)		+= i2c-core.o
+obj-$(CONFIG_I2C_SMBUS)		+= i2c-smbus.o
 obj-$(CONFIG_I2C_CHARDEV)	+= i2c-dev.o
 obj-y				+= busses/ chips/ algos/
 

drivers/i2c/algos/i2c-algo-pca.c

@@ -453,8 +453,6 @@ static int pca_init(struct i2c_adapter *adap)
 		 */
 		int raise_fall_time;
 
-		struct i2c_algo_pca_data *pca_data = adap->algo_data;
-
 		/* Ignore the reset function from the module,
 		 * we can use the parallel bus reset
 		 */

drivers/i2c/busses/Kconfig

@@ -77,7 +77,7 @@ config I2C_AMD8111
 	  will be called i2c-amd8111.
 
 config I2C_I801
-	tristate "Intel 82801 (ICH)"
+	tristate "Intel 82801 (ICH/PCH)"
 	depends on PCI
 	help
 	  If you say yes to this option, support will be included for the Intel
@@ -97,7 +97,8 @@ config I2C_I801
 	    ICH9
 	    Tolapai
 	    ICH10
-	    PCH
+	    3400/5 Series (PCH)
+	    Cougar Point (PCH)
 
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-i801.
@@ -580,6 +581,7 @@ config I2C_PARPORT
 	tristate "Parallel port adapter"
 	depends on PARPORT
 	select I2C_ALGOBIT
+	select I2C_SMBUS
 	help
 	  This supports parallel port I2C adapters such as the ones made by
 	  Philips or Velleman, Analog Devices evaluation boards, and more.
@@ -603,6 +605,7 @@ config I2C_PARPORT
 config I2C_PARPORT_LIGHT
 	tristate "Parallel port adapter (light)"
 	select I2C_ALGOBIT
+	select I2C_SMBUS
 	help
 	  This supports parallel port I2C adapters such as the ones made by
 	  Philips or Velleman, Analog Devices evaluation boards, and more.

drivers/i2c/busses/i2c-ali1535.c

@@ -480,7 +480,7 @@ static struct i2c_adapter ali1535_adapter = {
 	.algo		= &smbus_algorithm,
 };
 
-static struct pci_device_id ali1535_ids[] = {
+static const struct pci_device_id ali1535_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
 	{ },
 };

drivers/i2c/busses/i2c-ali1563.c

@@ -417,7 +417,7 @@ static void __devexit ali1563_remove(struct pci_dev * dev)
 	ali1563_shutdown(dev);
 }
 
-static struct pci_device_id __devinitdata ali1563_id_table[] = {
+static const struct pci_device_id ali1563_id_table[] __devinitconst = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1563) },
 	{},
 };

drivers/i2c/busses/i2c-ali15x3.c

@@ -477,7 +477,7 @@ static struct i2c_adapter ali15x3_adapter = {
 	.algo		= &smbus_algorithm,
 };
 
-static struct pci_device_id ali15x3_ids[] = {
+static const struct pci_device_id ali15x3_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
 	{ 0, }
 };

drivers/i2c/busses/i2c-amd756.c

@@ -308,7 +308,7 @@ static const char* chipname[] = {
 	"nVidia nForce", "AMD8111",
 };
 
-static struct pci_device_id amd756_ids[] = {
+static const struct pci_device_id amd756_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_740B),
 	  .driver_data = AMD756 },
 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_7413),

drivers/i2c/busses/i2c-amd8111.c

@@ -351,7 +351,7 @@ static const struct i2c_algorithm smbus_algorithm = {
 };
 
 
-static struct pci_device_id amd8111_ids[] = {
+static const struct pci_device_id amd8111_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_8111_SMBUS2) },
 	{ 0, }
 };

drivers/i2c/busses/i2c-hydra.c

@@ -105,7 +105,7 @@ static struct i2c_adapter hydra_adap = {
 	.algo_data	= &hydra_bit_data,
 };
 
-static struct pci_device_id hydra_ids[] = {
+static const struct pci_device_id hydra_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_HYDRA) },
 	{ 0, }
 };

drivers/i2c/busses/i2c-i801.c

@@ -41,7 +41,8 @@
   Tolapai               0x5032     32     hard     yes     yes     yes
   ICH10                 0x3a30     32     hard     yes     yes     yes
   ICH10                 0x3a60     32     hard     yes     yes     yes
-  PCH                   0x3b30     32     hard     yes     yes     yes
+  3400/5 Series (PCH)   0x3b30     32     hard     yes     yes     yes
+  Cougar Point (PCH)    0x1c22     32     hard     yes     yes     yes
 
   Features supported by this driver:
   Software PEC                     no
@@ -561,7 +562,7 @@ static struct i2c_adapter i801_adapter = {
 	.algo		= &smbus_algorithm,
 };
 
-static struct pci_device_id i801_ids[] = {
+static const struct pci_device_id i801_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801AA_3) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801AB_3) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801BA_2) },
@@ -578,6 +579,7 @@ static struct pci_device_id i801_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH10_4) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH10_5) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_PCH_SMBUS) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_CPT_SMBUS) },
 	{ 0, }
 };
 
@@ -707,6 +709,7 @@ static int __devinit i801_probe(struct pci_dev *dev, const struct pci_device_id
 	case PCI_DEVICE_ID_INTEL_ICH10_4:
 	case PCI_DEVICE_ID_INTEL_ICH10_5:
 	case PCI_DEVICE_ID_INTEL_PCH_SMBUS:
+	case PCI_DEVICE_ID_INTEL_CPT_SMBUS:
 		i801_features |= FEATURE_I2C_BLOCK_READ;
 		/* fall through */
 	case PCI_DEVICE_ID_INTEL_82801DB_3:

drivers/i2c/busses/i2c-isch.c

@@ -256,7 +256,7 @@ static struct i2c_adapter sch_adapter = {
 	.algo		= &smbus_algorithm,
 };
 
-static struct pci_device_id sch_ids[] = {
+static const struct pci_device_id sch_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_SCH_LPC) },
 	{ 0, }
 };

drivers/i2c/busses/i2c-nforce2.c

@@ -308,7 +308,7 @@ static struct i2c_algorithm smbus_algorithm = {
 };
 
 
-static struct pci_device_id nforce2_ids[] = {
+static const struct pci_device_id nforce2_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE2_SMBUS) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE2S_SMBUS) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE3_SMBUS) },

drivers/i2c/busses/i2c-parport-light.c

 /* ------------------------------------------------------------------------ *
  * i2c-parport-light.c I2C bus over parallel port                           *
  * ------------------------------------------------------------------------ *
-   Copyright (C) 2003-2007 Jean Delvare <khali@linux-fr.org>
+   Copyright (C) 2003-2010 Jean Delvare <khali@linux-fr.org>
    
    Based on older i2c-velleman.c driver
    Copyright (C) 1995-2000 Simon G. Vogl
@@ -27,10 +27,12 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
+#include <linux/delay.h>
 #include <linux/platform_device.h>
 #include <linux/ioport.h>
 #include <linux/i2c.h>
 #include <linux/i2c-algo-bit.h>
+#include <linux/i2c-smbus.h>
 #include <asm/io.h>
 #include "i2c-parport.h"
 
@@ -43,6 +45,10 @@ static u16 base;
 module_param(base, ushort, 0);
 MODULE_PARM_DESC(base, "Base I/O address");
 
+static int irq;
+module_param(irq, int, 0);
+MODULE_PARM_DESC(irq, "IRQ (optional)");
+
 /* ----- Low-level parallel port access ----------------------------------- */
 
 static inline void port_write(unsigned char p, unsigned char d)
@@ -119,6 +125,16 @@ static struct i2c_adapter parport_adapter = {
 	.name		= "Parallel port adapter (light)",
 };
 
+/* SMBus alert support */
+static struct i2c_smbus_alert_setup alert_data = {
+	.alert_edge_triggered	= 1,
+};
+static struct i2c_client *ara;
+static struct lineop parport_ctrl_irq = {
+	.val		= (1 << 4),
+	.port		= CTRL,
+};
+
 static int __devinit i2c_parport_probe(struct platform_device *pdev)
 {
 	int err;
@@ -127,18 +143,39 @@ static int __devinit i2c_parport_probe(struct platform_device *pdev)
 	parport_setsda(NULL, 1);
 	parport_setscl(NULL, 1);
 	/* Other init if needed (power on...) */
-	if (adapter_parm[type].init.val)
+	if (adapter_parm[type].init.val) {
 		line_set(1, &adapter_parm[type].init);
+		/* Give powered devices some time to settle */
+		msleep(100);
+	}
 
 	parport_adapter.dev.parent = &pdev->dev;
 	err = i2c_bit_add_bus(&parport_adapter);
-	if (err)
+	if (err) {
 		dev_err(&pdev->dev, "Unable to register with I2C\n");
-	return err;
+		return err;
+	}
+
+	/* Setup SMBus alert if supported */
+	if (adapter_parm[type].smbus_alert && irq) {
+		alert_data.irq = irq;
+		ara = i2c_setup_smbus_alert(&parport_adapter, &alert_data);
+		if (ara)
+			line_set(1, &parport_ctrl_irq);
+		else
+			dev_warn(&pdev->dev, "Failed to register ARA client\n");
+	}
+
+	return 0;
 }
 
 static int __devexit i2c_parport_remove(struct platform_device *pdev)
 {
+	if (ara) {
+		line_set(0, &parport_ctrl_irq);
+		i2c_unregister_device(ara);
+		ara = NULL;
+	}
 	i2c_del_adapter(&parport_adapter);
 
 	/* Un-init if needed (power off...) */
@@ -205,6 +242,9 @@ static int __init i2c_parport_init(void)
 	if (!request_region(base, 3, DRVNAME))
 		return -EBUSY;
 
+	if (irq != 0)
+		pr_info(DRVNAME ": using irq %d\n", irq);
+
         if (!adapter_parm[type].getscl.val)
 		parport_algo_data.getscl = NULL;
 

drivers/i2c/busses/i2c-parport.c

 /* ------------------------------------------------------------------------ *
  * i2c-parport.c I2C bus over parallel port                                 *
  * ------------------------------------------------------------------------ *
-   Copyright (C) 2003-2007 Jean Delvare <khali@linux-fr.org>
+   Copyright (C) 2003-2010 Jean Delvare <khali@linux-fr.org>
    
    Based on older i2c-philips-par.c driver
    Copyright (C) 1995-2000 Simon G. Vogl
@@ -27,9 +27,11 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
+#include <linux/delay.h>
 #include <linux/parport.h>
 #include <linux/i2c.h>
 #include <linux/i2c-algo-bit.h>
+#include <linux/i2c-smbus.h>
 #include "i2c-parport.h"
 
 /* ----- Device list ------------------------------------------------------ */
@@ -38,6 +40,8 @@ struct i2c_par {
 	struct pardevice *pdev;
 	struct i2c_adapter adapter;
 	struct i2c_algo_bit_data algo_data;
+	struct i2c_smbus_alert_setup alert_data;
+	struct i2c_client *ara;
 	struct i2c_par *next;
 };
 
@@ -143,6 +147,19 @@ static struct i2c_algo_bit_data parport_algo_data = {
 
 /* ----- I2c and parallel port call-back functions and structures --------- */
 
+void i2c_parport_irq(void *data)
+{
+	struct i2c_par *adapter = data;
+	struct i2c_client *ara = adapter->ara;
+
+	if (ara) {
+		dev_dbg(&ara->dev, "SMBus alert received\n");
+		i2c_handle_smbus_alert(ara);
+	} else
+		dev_dbg(&adapter->adapter.dev,
+			"SMBus alert received but no ARA client!\n");
+}
+
 static void i2c_parport_attach (struct parport *port)
 {
 	struct i2c_par *adapter;
@@ -154,8 +171,9 @@ static void i2c_parport_attach (struct parport *port)
 	}
 
 	pr_debug("i2c-parport: attaching to %s\n", port->name);
+	parport_disable_irq(port);
 	adapter->pdev = parport_register_device(port, "i2c-parport",
-		NULL, NULL, NULL, PARPORT_FLAG_EXCL, NULL);
+		NULL, NULL, i2c_parport_irq, PARPORT_FLAG_EXCL, adapter);
 	if (!adapter->pdev) {
 		printk(KERN_ERR "i2c-parport: Unable to register with parport\n");
 		goto ERROR0;
@@ -185,14 +203,29 @@ static void i2c_parport_attach (struct parport *port)
 	parport_setsda(port, 1);
 	parport_setscl(port, 1);
 	/* Other init if needed (power on...) */
-	if (adapter_parm[type].init.val)
+	if (adapter_parm[type].init.val) {
 		line_set(port, 1, &adapter_parm[type].init);
+		/* Give powered devices some time to settle */
+		msleep(100);
+	}
 
 	if (i2c_bit_add_bus(&adapter->adapter) < 0) {
 		printk(KERN_ERR "i2c-parport: Unable to register with I2C\n");
 		goto ERROR1;
 	}
 
+	/* Setup SMBus alert if supported */
+	if (adapter_parm[type].smbus_alert) {
+		adapter->alert_data.alert_edge_triggered = 1;
+		adapter->ara = i2c_setup_smbus_alert(&adapter->adapter,
+						     &adapter->alert_data);
+		if (adapter->ara)
+			parport_enable_irq(port);
+		else
+			printk(KERN_WARNING "i2c-parport: Failed to register "
+			       "ARA client\n");
+	}
+
 	/* Add the new adapter to the list */
 	adapter->next = adapter_list;
 	adapter_list = adapter;
@@ -213,6 +246,10 @@ static void i2c_parport_detach (struct parport *port)
 	for (prev = NULL, adapter = adapter_list; adapter;
 	     prev = adapter, adapter = adapter->next) {
 		if (adapter->pdev->port == port) {
+			if (adapter->ara) {
+				parport_disable_irq(port);
+				i2c_unregister_device(adapter->ara);
+			}
 			i2c_del_adapter(&adapter->adapter);
 
 			/* Un-init if needed (power off...) */

drivers/i2c/busses/i2c-parport.h

 /* ------------------------------------------------------------------------ *
  * i2c-parport.h I2C bus over parallel port                                 *
  * ------------------------------------------------------------------------ *
-   Copyright (C) 2003-2004 Jean Delvare <khali@linux-fr.org>
+   Copyright (C) 2003-2010 Jean Delvare <khali@linux-fr.org>
    
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -38,6 +38,7 @@ struct adapter_parm {
 	struct lineop getsda;
 	struct lineop getscl;
 	struct lineop init;
+	unsigned int smbus_alert:1;
 };
 
 static struct adapter_parm adapter_parm[] = {
@@ -73,6 +74,7 @@ static struct adapter_parm adapter_parm[] = {
 		.setscl	= { 0x01, DATA, 1 },
 		.getsda	= { 0x10, STAT, 1 },
 		.init	= { 0xf0, DATA, 0 },
+		.smbus_alert = 1,
 	},
 	/* type 5: ADM1025, ADM1030 and ADM1031 evaluation boards */
 	{

drivers/i2c/busses/i2c-pasemi.c

@@ -400,7 +400,7 @@ static void __devexit pasemi_smb_remove(struct pci_dev *dev)
 	kfree(smbus);
 }
 
-static struct pci_device_id pasemi_smb_ids[] = {
+static const struct pci_device_id pasemi_smb_ids[] = {
 	{ PCI_DEVICE(0x1959, 0xa003) },
 	{ 0, }
 };

drivers/i2c/busses/i2c-piix4.c

@@ -472,7 +472,7 @@ static struct i2c_adapter piix4_adapter = {
 	.algo		= &smbus_algorithm,
 };
 
-static struct pci_device_id piix4_ids[] = {
+static const struct pci_device_id piix4_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371AB_3) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443MX_3) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_EFAR, PCI_DEVICE_ID_EFAR_SLC90E66_3) },

drivers/i2c/busses/i2c-sis5595.c

@@ -369,7 +369,7 @@ static struct i2c_adapter sis5595_adapter = {
 	.algo		= &smbus_algorithm,
 };
 
-static struct pci_device_id sis5595_ids[] __devinitdata = {
+static const struct pci_device_id sis5595_ids[] __devinitconst = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_503) }, 
 	{ 0, }
 };

drivers/i2c/busses/i2c-sis630.c

@@ -468,7 +468,7 @@ static struct i2c_adapter sis630_adapter = {
 	.algo		= &smbus_algorithm,
 };
 
-static struct pci_device_id sis630_ids[] __devinitdata = {
+static const struct pci_device_id sis630_ids[] __devinitconst = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_503) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_LPC) },
 	{ 0, }

drivers/i2c/busses/i2c-sis96x.c

@@ -245,7 +245,7 @@ static struct i2c_adapter sis96x_adapter = {
 	.algo		= &smbus_algorithm,
 };
 
-static struct pci_device_id sis96x_ids[] = {
+static const struct pci_device_id sis96x_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_SMBUS) },
 	{ 0, }
 };

drivers/i2c/busses/i2c-tiny-usb.c

@@ -31,11 +31,13 @@
 #define CMD_I2C_IO_BEGIN	(1<<0)
 #define CMD_I2C_IO_END		(1<<1)
 
-/* i2c bit delay, default is 10us -> 100kHz */
+/* i2c bit delay, default is 10us -> 100kHz max
+   (in practice, due to additional delays in the i2c bitbanging
+   code this results in a i2c clock of about 50kHz) */
 static unsigned short delay = 10;
 module_param(delay, ushort, 0);
-MODULE_PARM_DESC(delay, "bit delay in microseconds, "
-		 "e.g. 10 for 100kHz (default is 100kHz)");
+MODULE_PARM_DESC(delay, "bit delay in microseconds "
+		 "(default is 10us for 100kHz max)");
 
 static int usb_read(struct i2c_adapter *adapter, int cmd,
 		    int value, int index, void *data, int len);
@@ -137,7 +139,7 @@ static const struct i2c_algorithm usb_algorithm = {
  * Future Technology Devices International Ltd., later a pair was
  * bought from EZPrototypes
  */
-static struct usb_device_id i2c_tiny_usb_table [] = {
+static const struct usb_device_id i2c_tiny_usb_table[] = {
 	{ USB_DEVICE(0x0403, 0xc631) },   /* FTDI */
 	{ USB_DEVICE(0x1c40, 0x0534) },   /* EZPrototypes */
 	{ }                               /* Terminating entry */

drivers/i2c/busses/i2c-via.c

@@ -89,7 +89,7 @@ static struct i2c_adapter vt586b_adapter = {
 };
 
 
-static struct pci_device_id vt586b_ids[] __devinitdata = {
+static const struct pci_device_id vt586b_ids[] __devinitconst = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C586_3) },
 	{ 0, }
 };

drivers/i2c/busses/i2c-viapro.c

@@ -444,7 +444,7 @@ release_region:
 	return error;
 }
 
-static struct pci_device_id vt596_ids[] = {
+static const struct pci_device_id vt596_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596_3),
 	  .driver_data = SMBBA1 },
 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596B_3),

drivers/i2c/i2c-core.c

@@ -34,6 +34,7 @@
 #include <linux/hardirq.h>
 #include <linux/irqflags.h>
 #include <linux/rwsem.h>
+#include <linux/pm_runtime.h>
 #include <asm/uaccess.h>
 
 #include "i2c-core.h"
@@ -184,6 +185,52 @@ static int i2c_device_pm_resume(struct device *dev)
 #define i2c_device_pm_resume	NULL
 #endif
 
+#ifdef CONFIG_PM_RUNTIME
+static int i2c_device_runtime_suspend(struct device *dev)
+{
+	const struct dev_pm_ops *pm;
+
+	if (!dev->driver)
+		return 0;
+	pm = dev->driver->pm;
+	if (!pm || !pm->runtime_suspend)
+		return 0;
+	return pm->runtime_suspend(dev);
+}
+
+static int i2c_device_runtime_resume(struct device *dev)
+{
+	const struct dev_pm_ops *pm;
+
+	if (!dev->driver)
+		return 0;
+	pm = dev->driver->pm;
+	if (!pm || !pm->runtime_resume)
+		return 0;
+	return pm->runtime_resume(dev);
+}
+
+static int i2c_device_runtime_idle(struct device *dev)
+{
+	const struct dev_pm_ops *pm = NULL;
+	int ret;
+
+	if (dev->driver)
+		pm = dev->driver->pm;
+	if (pm && pm->runtime_idle) {
+		ret = pm->runtime_idle(dev);
+		if (ret)
+			return ret;
+	}
+
+	return pm_runtime_suspend(dev);
+}
+#else
+#define i2c_device_runtime_suspend	NULL
+#define i2c_device_runtime_resume	NULL
+#define i2c_device_runtime_idle		NULL
+#endif
+
 static int i2c_device_suspend(struct device *dev, pm_message_t mesg)
 {
 	struct i2c_client *client = i2c_verify_client(dev);
@@ -251,6 +298,9 @@ static const struct attribute_group *i2c_dev_attr_groups[] = {
 static const struct dev_pm_ops i2c_device_pm_ops = {
 	.suspend = i2c_device_pm_suspend,
 	.resume = i2c_device_pm_resume,
+	.runtime_suspend = i2c_device_runtime_suspend,
+	.runtime_resume = i2c_device_runtime_resume,
+	.runtime_idle = i2c_device_runtime_idle,
 };
 
 struct bus_type i2c_bus_type = {
@@ -1133,7 +1183,7 @@ EXPORT_SYMBOL(i2c_transfer);
  * i2c_master_send - issue a single I2C message in master transmit mode
  * @client: Handle to slave device
  * @buf: Data that will be written to the slave
- * @count: How many bytes to write
+ * @count: How many bytes to write, must be less than 64k since msg.len is u16
  *
  * Returns negative errno, or else the number of bytes written.
  */
@@ -1160,7 +1210,7 @@ EXPORT_SYMBOL(i2c_master_send);
  * i2c_master_recv - issue a single I2C message in master receive mode
  * @client: Handle to slave device
  * @buf: Where to store data read from slave
- * @count: How many bytes to read
+ * @count: How many bytes to read, must be less than 64k since msg.len is u16
  *
  * Returns negative errno, or else the number of bytes read.
  */

drivers/i2c/i2c-smbus.c

+/*
+ * i2c-smbus.c - SMBus extensions to the I2C protocol
+ *
+ * Copyright (C) 2008 David Brownell
+ * Copyright (C) 2010 Jean Delvare <khali@linux-fr.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/semaphore.h>
+#include <linux/interrupt.h>
+#include <linux/workqueue.h>
+#include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
+
+struct i2c_smbus_alert {
+	unsigned int		alert_edge_triggered:1;
+	int			irq;
+	struct work_struct	alert;
+	struct i2c_client	*ara;		/* Alert response address */
+};
+
+struct alert_data {
+	unsigned short		addr;
+	u8			flag:1;
+};
+
+/* If this is the alerting device, notify its driver */
+static int smbus_do_alert(struct device *dev, void *addrp)
+{
+	struct i2c_client *client = i2c_verify_client(dev);
+	struct alert_data *data = addrp;
+
+	if (!client || client->addr != data->addr)
+		return 0;
+	if (client->flags & I2C_CLIENT_TEN)
+		return 0;
+
+	/*
+	 * Drivers should either disable alerts, or provide at least
+	 * a minimal handler.  Lock so client->driver won't change.
+	 */
+	down(&dev->sem);
+	if (client->driver) {
+		if (client->driver->alert)
+			client->driver->alert(client, data->flag);
+		else
+			dev_warn(&client->dev, "no driver alert()!\n");
+	} else
+		dev_dbg(&client->dev, "alert with no driver\n");
+	up(&dev->sem);
+
+	/* Stop iterating after we find the device */
+	return -EBUSY;
+}
+
+/*
+ * The alert IRQ handler needs to hand work off to a task which can issue
+ * SMBus calls, because those sleeping calls can't be made in IRQ context.
+ */
+static void smbus_alert(struct work_struct *work)
+{
+	struct i2c_smbus_alert *alert;
+	struct i2c_client *ara;
+	unsigned short prev_addr = 0;	/* Not a valid address */
+
+	alert = container_of(work, struct i2c_smbus_alert, alert);
+	ara = alert->ara;
+
+	for (;;) {
+		s32 status;
+		struct alert_data data;
+
+		/*
+		 * Devices with pending alerts reply in address order, low
+		 * to high, because of slave transmit arbitration.  After
+		 * responding, an SMBus device stops asserting SMBALERT#.
+		 *
+		 * Note that SMBus 2.0 reserves 10-bit addresess for future
+		 * use.  We neither handle them, nor try to use PEC here.
+		 */
+		status = i2c_smbus_read_byte(ara);
+		if (status < 0)
+			break;
+
+		data.flag = status & 1;
+		data.addr = status >> 1;
+
+		if (data.addr == prev_addr) {
+			dev_warn(&ara->dev, "Duplicate SMBALERT# from dev "
+				"0x%02x, skipping\n", data.addr);
+			break;
+		}
+		dev_dbg(&ara->dev, "SMBALERT# from dev 0x%02x, flag %d\n",
+			data.addr, data.flag);
+
+		/* Notify driver for the device which issued the alert */
+		device_for_each_child(&ara->adapter->dev, &data,
+				      smbus_do_alert);
+		prev_addr = data.addr;
+	}
+
+	/* We handled all alerts; re-enable level-triggered IRQs */
+	if (!alert->alert_edge_triggered)
+		enable_irq(alert->irq);
+}
+
+static irqreturn_t smbalert_irq(int irq, void *d)
+{
+	struct i2c_smbus_alert *alert = d;
+
+	/* Disable level-triggered IRQs until we handle them */
+	if (!alert->alert_edge_triggered)
+		disable_irq_nosync(irq);
+
+	schedule_work(&alert->alert);
+	return IRQ_HANDLED;
+}
+
+/* Setup SMBALERT# infrastructure */
+static int smbalert_probe(struct i2c_client *ara,
+			  const struct i2c_device_id *id)
+{
+	struct i2c_smbus_alert_setup *setup = ara->dev.platform_data;
+	struct i2c_smbus_alert *alert;
+	struct i2c_adapter *adapter = ara->adapter;
+	int res;
+
+	alert = kzalloc(sizeof(struct i2c_smbus_alert), GFP_KERNEL);
+	if (!alert)
+		return -ENOMEM;
+
+	alert->alert_edge_triggered = setup->alert_edge_triggered;
+	alert->irq = setup->irq;
+	INIT_WORK(&alert->alert, smbus_alert);
+	alert->ara = ara;
+
+	if (setup->irq > 0) {
+		res = devm_request_irq(&ara->dev, setup->irq, smbalert_irq,
+				       0, "smbus_alert", alert);
+		if (res) {
+			kfree(alert);
+			return res;
+		}
+	}
+
+	i2c_set_clientdata(ara, alert);
+	dev_info(&adapter->dev, "supports SMBALERT#, %s trigger\n",
+		 setup->alert_edge_triggered ? "edge" : "level");
+
+	return 0;
+}
+
+/* IRQ resource is managed so it is freed automatically */
+static int smbalert_remove(struct i2c_client *ara)
+{
+	struct i2c_smbus_alert *alert = i2c_get_clientdata(ara);
+
+	cancel_work_sync(&alert->alert);
+
+	i2c_set_clientdata(ara, NULL);
+	kfree(alert);
+	return 0;
+}
+
+static const struct i2c_device_id smbalert_ids[] = {
+	{ "smbus_alert", 0 },
+	{ /* LIST END */ }
+};
+MODULE_DEVICE_TABLE(i2c, smbalert_ids);
+
+static struct i2c_driver smbalert_driver = {
+	.driver = {
+		.name	= "smbus_alert",
+	},
+	.probe		= smbalert_probe,
+	.remove		= smbalert_remove,
+	.id_table	= smbalert_ids,
+};
+
+/**
+ * i2c_setup_smbus_alert - Setup SMBus alert support
+ * @adapter: the target adapter
+ * @setup: setup data for the SMBus alert handler
+ * Context: can sleep
+ *
+ * Setup handling of the SMBus alert protocol on a given I2C bus segment.
+ *
+ * Handling can be done either through our IRQ handler, or by the
+ * adapter (from its handler, periodic polling, or whatever).
+ *
+ * NOTE that if we manage the IRQ, we *MUST* know if it's level or
+ * edge triggered in order to hand it to the workqueue correctly.
+ * If triggering the alert seems to wedge the system, you probably
+ * should have said it's level triggered.
+ *
+ * This returns the ara client, which should be saved for later use with
+ * i2c_handle_smbus_alert() and ultimately i2c_unregister_device(); or NULL
+ * to indicate an error.
+ */
+struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter,
+					 struct i2c_smbus_alert_setup *setup)
+{
+	struct i2c_board_info ara_board_info = {
+		I2C_BOARD_INFO("smbus_alert", 0x0c),
+		.platform_data = setup,
+	};
+
+	return i2c_new_device(adapter, &ara_board_info);
+}
+EXPORT_SYMBOL_GPL(i2c_setup_smbus_alert);
+
+/**
+ * i2c_handle_smbus_alert - Handle an SMBus alert
+ * @ara: the ARA client on the relevant adapter
+ * Context: can't sleep
+ *
+ * Helper function to be called from an I2C bus driver's interrupt
+ * handler. It will schedule the alert work, in turn calling the
+ * corresponding I2C device driver's alert function.
+ *
+ * It is assumed that ara is a valid i2c client previously returned by
+ * i2c_setup_smbus_alert().
+ */
+int i2c_handle_smbus_alert(struct i2c_client *ara)
+{
+	struct i2c_smbus_alert *alert = i2c_get_clientdata(ara);
+
+	return schedule_work(&alert->alert);
+}
+EXPORT_SYMBOL_GPL(i2c_handle_smbus_alert);
+
+static int __init i2c_smbus_init(void)
+{
+	return i2c_add_driver(&smbalert_driver);
+}
+
+static void __exit i2c_smbus_exit(void)
+{
+	i2c_del_driver(&smbalert_driver);
+}
+
+module_init(i2c_smbus_init);
+module_exit(i2c_smbus_exit);
+
+MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
+MODULE_DESCRIPTION("SMBus protocol extensions support");
+MODULE_LICENSE("GPL");

include/linux/i2c-smbus.h

+/*
+ * i2c-smbus.h - SMBus extensions to the I2C protocol
+ *
+ * Copyright (C) 2010 Jean Delvare <khali@linux-fr.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef _LINUX_I2C_SMBUS_H
+#define _LINUX_I2C_SMBUS_H
+
+#include <linux/i2c.h>
+
+
+/**
+ * i2c_smbus_alert_setup - platform data for the smbus_alert i2c client
+ * @alert_edge_triggered: whether the alert interrupt is edge (1) or level (0)
+ *		triggered
+ * @irq: IRQ number, if the smbus_alert driver should take care of interrupt
+ *		handling
+ *
+ * If irq is not specified, the smbus_alert driver doesn't take care of
+ * interrupt handling. In that case it is up to the I2C bus driver to either
+ * handle the interrupts or to poll for alerts.
+ *
+ * If irq is specified then it it crucial that alert_edge_triggered is
+ * properly set.
+ */
+struct i2c_smbus_alert_setup {
+	unsigned int		alert_edge_triggered:1;
+	int			irq;
+};
+
+struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter,
+					 struct i2c_smbus_alert_setup *setup);
+int i2c_handle_smbus_alert(struct i2c_client *ara);
+
+#endif /* _LINUX_I2C_SMBUS_H */

include/linux/i2c.h

@@ -53,6 +53,7 @@ struct i2c_board_info;
  * on a bus (or read from them). Apart from two basic transfer functions to
  * transmit one message at a time, a more complex version can be used to
  * transmit an arbitrary number of messages without interruption.
+ * @count must be be less than 64k since msg.len is u16.
  */
 extern int i2c_master_send(struct i2c_client *client, const char *buf,
 			   int count);
@@ -152,6 +153,13 @@ struct i2c_driver {
 	int (*suspend)(struct i2c_client *, pm_message_t mesg);
 	int (*resume)(struct i2c_client *);
 
+	/* Alert callback, for example for the SMBus alert protocol.
+	 * The format and meaning of the data value depends on the protocol.
+	 * For the SMBus alert protocol, there is a single bit of data passed
+	 * as the alert response's low bit ("event flag").
+	 */
+	void (*alert)(struct i2c_client *, unsigned int data);
+
 	/* a ioctl like command that can be used to perform specific functions
 	 * with the device.
 	 */