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

Pull i2c updates from Wolfram Sang:
 "Most notable:

   - introducing the i2c_quirk infrastructure.  Now, flaws of I2C
     controllers can be described and the core will check if the flaws
     collide with the messages to be sent

   - wait_for_completion return type cleanup series

   - new drivers for Digicolor, Netlogic XLP, Ingenic JZ4780

   - updates to the I2C slave framework which include API changes.  Its
     only user was updated, too.  Documentation was finally added

   - changed dynamic bus numbering for the DT case.  This could change
     bus numbers for users.  However, it fixes a collision where dynamic
     and static busses request the same id.

   - driver bugfixes, cleanups"

* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (52 commits)
  i2c: xlp9xx: Driver for Netlogic XLP9XX/5XX I2C controller
  of: Add vendor prefix 'netlogic'
  i2c: davinci: use ICPFUNC to toggle I2C as gpio for bus recovery
  i2c: davinci: use bus recovery infrastructure
  i2c: change input parameter to i2c_adapter for prepare/unprepare_recovery
  i2c: i2c-mux-gpio: remove error messages for probe deferrals
  i2c: jz4780: Add i2c bus controller driver for Ingenic JZ4780
  i2c: dln2: set the device tree node of the adapter
  i2c: davinci: fixup wait_for_completion_timeout handling
  i2c: mpc: Fix ISR return value
  i2c: slave-eeprom: add more info when to increase the pointer
  i2c: slave: add documentation for i2c-slave-eeprom
  Documentation: i2c: describe the new slave mode
  i2c: slave: rework the slave API
  i2c: add support for the Digicolor I2C controller
  i2c: busses with dynamic ids should start after fixed ids for DT
  of: base: add function to get highest id of an alias stem
  i2c: designware: Suppress error message if platform_get_irq() < 0
  i2c: mpc: assign the correct prescaler from SVR
  i2c: img-scb: fixup of wait_for_completion_timeout return handling
  ...

3 files changed, 56 insertions, 6 deletions

diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index f17da50402a4..898033f41d76 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -253,10 +253,10 @@ static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
 
 #if IS_ENABLED(CONFIG_I2C_SLAVE)
 enum i2c_slave_event {
-        I2C_SLAVE_REQ_READ_START,
-        I2C_SLAVE_REQ_READ_END,
-        I2C_SLAVE_REQ_WRITE_START,
-        I2C_SLAVE_REQ_WRITE_END,
+        I2C_SLAVE_READ_REQUESTED,
+        I2C_SLAVE_WRITE_REQUESTED,
+        I2C_SLAVE_READ_PROCESSED,
+        I2C_SLAVE_WRITE_RECEIVED,
         I2C_SLAVE_STOP,
 };
 
@@ -435,8 +435,8 @@ struct i2c_bus_recovery_info {
         void (*set_scl)(struct i2c_adapter *, int val);
         int (*get_sda)(struct i2c_adapter *);
 
-        void (*prepare_recovery)(struct i2c_bus_recovery_info *bri);
-        void (*unprepare_recovery)(struct i2c_bus_recovery_info *bri);
+        void (*prepare_recovery)(struct i2c_adapter *);
+        void (*unprepare_recovery)(struct i2c_adapter *);
 
         /* gpio recovery */
         int scl_gpio;
@@ -449,6 +449,48 @@ int i2c_recover_bus(struct i2c_adapter *adap);
 int i2c_generic_gpio_recovery(struct i2c_adapter *adap);
 int i2c_generic_scl_recovery(struct i2c_adapter *adap);
 
+/**
+ * struct i2c_adapter_quirks - describe flaws of an i2c adapter
+ * @flags: see I2C_AQ_* for possible flags and read below
+ * @max_num_msgs: maximum number of messages per transfer
+ * @max_write_len: maximum length of a write message
+ * @max_read_len: maximum length of a read message
+ * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
+ * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
+ *
+ * Note about combined messages: Some I2C controllers can only send one message
+ * per transfer, plus something called combined message or write-then-read.
+ * This is (usually) a small write message followed by a read message and
+ * barely enough to access register based devices like EEPROMs. There is a flag
+ * to support this mode. It implies max_num_msg = 2 and does the length checks
+ * with max_comb_*_len because combined message mode usually has its own
+ * limitations. Because of HW implementations, some controllers can actually do
+ * write-then-anything or other variants. To support that, write-then-read has
+ * been broken out into smaller bits like write-first and read-second which can
+ * be combined as needed.
+ */
+
+struct i2c_adapter_quirks {
+        u64 flags;
+        int max_num_msgs;
+        u16 max_write_len;
+        u16 max_read_len;
+        u16 max_comb_1st_msg_len;
+        u16 max_comb_2nd_msg_len;
+};
+
+/* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
+#define I2C_AQ_COMB                     BIT(0)
+/* first combined message must be write */
+#define I2C_AQ_COMB_WRITE_FIRST         BIT(1)
+/* second combined message must be read */
+#define I2C_AQ_COMB_READ_SECOND         BIT(2)
+/* both combined messages must have the same target address */
+#define I2C_AQ_COMB_SAME_ADDR           BIT(3)
+/* convenience macro for typical write-then read case */
+#define I2C_AQ_COMB_WRITE_THEN_READ     (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
+                                         I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
+
 /*
  * i2c_adapter is the structure used to identify a physical i2c bus along
  * with the access algorithms necessary to access it.
@@ -474,6 +516,7 @@ struct i2c_adapter {
         struct list_head userspace_clients;
 
         struct i2c_bus_recovery_info *bus_recovery_info;
+        const struct i2c_adapter_quirks *quirks;
 };
 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
 
diff --git a/include/linux/of.h b/include/linux/of.h
index dfde07e77a63..9bfcc18ceab3 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -332,6 +332,7 @@ extern int of_count_phandle_with_args(const struct device_node *np,
 
 extern void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align));
 extern int of_alias_get_id(struct device_node *np, const char *stem);
+extern int of_alias_get_highest_id(const char *stem);
 
 extern int of_machine_is_compatible(const char *compat);
 
@@ -594,6 +595,11 @@ static inline int of_alias_get_id(struct device_node *np, const char *stem)
         return -ENOSYS;
 }
 
+static inline int of_alias_get_highest_id(const char *stem)
+{
+        return -ENOSYS;
+}
+
 static inline int of_machine_is_compatible(const char *compat)
 {
         return 0;
diff --git a/include/linux/platform_data/i2c-davinci.h b/include/linux/platform_data/i2c-davinci.h
index 2312d197dfb7..89fd34727a24 100644
--- a/include/linux/platform_data/i2c-davinci.h
+++ b/include/linux/platform_data/i2c-davinci.h
@@ -18,6 +18,7 @@ struct davinci_i2c_platform_data {
         unsigned int    bus_delay;      /* post-transaction delay (usec) */
         unsigned int    sda_pin;        /* GPIO pin ID to use for SDA */
         unsigned int    scl_pin;        /* GPIO pin ID to use for SCL */
+        bool            has_pfunc;      /*chip has a ICPFUNC register */
 };
 
 /* for board setup code */