Merge branch 'i2c/for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:

 - API for late atomic transfers (e.g. to shut down via PMIC). We have a
   seperate callback now which is called under clearly defined
   conditions. In-kernel users are converted, too.

 - new driver for the AMD PCIe MP2 I2C controller

 - large refactoring for at91 and bcm-iproc (both gain slave support due
   to this)

 - and a good share of various driver improvements anf fixes

* 'i2c/for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (57 commits)
  dt-bindings: i2c: riic: document r7s9210 support
  i2c: imx-lpi2c: Use __maybe_unused instead of #if CONFIG_PM_SLEEP
  i2c-piix4: Add Hygon Dhyana SMBus support
  i2c: core: apply 'is_suspended' check for SMBus, too
  i2c: core: ratelimit 'transfer when suspended' errors
  i2c: iproc: Change driver to use 'BIT' macro
  i2c: riic: Add Runtime PM support
  i2c: mux: demux-pinctrl: use struct_size() in devm_kzalloc()
  i2c: mux: pca954x: allow management of device idle state via sysfs
  i2c: mux: pca9541: remove support for unused platform data
  i2c: mux: pca954x: remove support for unused platform data
  dt-bindings: i2c: i2c-mtk: add support for MT8516
  i2c: axxia: use auto cmd for last message
  i2c: gpio: flag atomic capability if possible
  i2c: algo: bit: add flag to whitelist atomic transfers
  i2c: stu300: use xfer_atomic callback to bail out early
  i2c: ocores: enable atomic xfers
  i2c: ocores: refactor setup for polling
  i2c: tegra-bpmp: convert to use new atomic callbacks
  i2c: omap: Add the master_xfer_atomic hook
  ...

1 files changed, 27 insertions, 14 deletions

diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 383510b4f083..be27062f8ed1 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -499,9 +499,13 @@ i2c_register_board_info(int busnum, struct i2c_board_info const *info,
  * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
  *   defined by the msgs array, with num messages available to transfer via
  *   the adapter specified by adap.
+ * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context
+ *   so e.g. PMICs can be accessed very late before shutdown. Optional.
  * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
  *   is not present, then the bus layer will try and convert the SMBus calls
  *   into I2C transfers instead.
+ * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context
+ *   so e.g. PMICs can be accessed very late before shutdown. Optional.
  * @functionality: Return the flags that this algorithm/adapter pair supports
  *   from the I2C_FUNC_* flags.
  * @reg_slave: Register given client to I2C slave mode of this adapter
@@ -512,25 +516,33 @@ i2c_register_board_info(int busnum, struct i2c_board_info const *info,
  * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
  * to name two of the most common.
  *
- * The return codes from the @master_xfer field should indicate the type of
- * error code that occurred during the transfer, as documented in the kernel
- * Documentation file Documentation/i2c/fault-codes.
+ * The return codes from the @master_xfer{_atomic} fields should indicate the
+ * type of error code that occurred during the transfer, as documented in the
+ * Kernel Documentation file Documentation/i2c/fault-codes.
  */
 struct i2c_algorithm {
-	/* If an adapter algorithm can't do I2C-level access, set master_xfer
-	   to NULL. If an adapter algorithm can do SMBus access, set
-	   smbus_xfer. If set to NULL, the SMBus protocol is simulated
-	   using common I2C messages */
-	/* master_xfer should return the number of messages successfully
-	   processed, or a negative value on error */
+	/*
+	 * If an adapter algorithm can't do I2C-level access, set master_xfer
+	 * to NULL. If an adapter algorithm can do SMBus access, set
+	 * smbus_xfer. If set to NULL, the SMBus protocol is simulated
+	 * using common I2C messages.
+	 *
+	 * master_xfer should return the number of messages successfully
+	 * processed, or a negative value on error
+	 */
 	int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
 			   int num);
-	int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
-			   unsigned short flags, char read_write,
-			   u8 command, int size, union i2c_smbus_data *data);
+	int (*master_xfer_atomic)(struct i2c_adapter *adap,
+				   struct i2c_msg *msgs, int num);
+	int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr,
+			  unsigned short flags, char read_write,
+			  u8 command, int size, union i2c_smbus_data *data);
+	int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr,
+				 unsigned short flags, char read_write,
+				 u8 command, int size, union i2c_smbus_data *data);
 
 	/* To determine what the adapter supports */
-	u32 (*functionality) (struct i2c_adapter *);
+	u32 (*functionality)(struct i2c_adapter *adap);
 
 #if IS_ENABLED(CONFIG_I2C_SLAVE)
 	int (*reg_slave)(struct i2c_client *client);
@@ -682,7 +694,8 @@ struct i2c_adapter {
 	int retries;
 	struct device dev;		/* the adapter device */
 	unsigned long locked_flags;	/* owned by the I2C core */
-#define I2C_ALF_IS_SUSPENDED	0
+#define I2C_ALF_IS_SUSPENDED		0
+#define I2C_ALF_SUSPEND_REPORTED	1
 
 	int nr;
 	char name[48];