I2C for 6.11-rc1 second batch

The I2C core has two header documentation updates to be applied as the
 dependecies are in now.
 
 The I2C host drivers add some patches which nearly fell through the
 cracks, namely:
 
 Added descriptions in the DTS for the Qualcomm SM8650 and SM8550
 Camera Control Interface (CCI).
 
 Added support for the "settle-time-us" property, which allows the
 gpio-mux device to switch from one bus to another with a configurable
 delay. The time can be set in the DTS. The latest change also includes
 file sorting.
 
 Fixed slot numbering in the SMBus framework to prevent failures
 when more than 8 slots are occupied. It now enforces a a maximum
 of 8 slots to be used. This ensures that the Intel PIIX4 device
 can register the SPDs correctly without failure, even if other
 slots are populated but not used.
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Merge tag 'i2c-for-6.11-rc1-second-batch' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull more i2c updates from Wolfram Sang:
 "The I2C core has two header documentation updates as the dependecies
  are in now.

  The I2C host drivers add some patches which nearly fell through the
  cracks:

   - Added descriptions in the DTS for the Qualcomm SM8650 and SM8550
     Camera Control Interface (CCI).

   - Added support for the "settle-time-us" property, which allows the
     gpio-mux device to switch from one bus to another with a
     configurable delay. The time can be set in the DTS. The latest
     change also includes file sorting.

   - Fixed slot numbering in the SMBus framework to prevent failures
     when more than 8 slots are occupied. It now enforces a a maximum of
     8 slots to be used. This ensures that the Intel PIIX4 device can
     register the SPDs correctly without failure, even if other slots
     are populated but not used"

* tag 'i2c-for-6.11-rc1-second-batch' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: header: improve kdoc for i2c_algorithm
  i2c: header: remove unneeded stuff regarding i2c_algorithm
  i2c: piix4: Register SPDs
  i2c: smbus: remove i801 assumptions from SPD probing
  i2c: mux: gpio: Add support for the 'settle-time-us' property
  i2c: mux: gpio: Re-order #include to match alphabetic order
  dt-bindings: i2c: mux-gpio: Add 'settle-time-us' property
  dt-bindings: i2c: qcom-cci: Document sm8650 compatible
  dt-bindings: i2c: qcom-cci: Document sm8550 compatible

Documentation/devicetree/bindings/i2c/i2c-mux-gpio.yaml

@@ -57,6 +57,9 @@ properties:
       last value used.
     $ref: /schemas/types.yaml#/definitions/uint32
 
+  settle-time-us:
+    description: Delay to wait before doing any transfer when a new bus gets selected.
+
 allOf:
   - $ref: i2c-mux.yaml
 

Documentation/devicetree/bindings/i2c/qcom,i2c-cci.yaml

@@ -31,6 +31,8 @@ properties:
               - qcom,sm6350-cci
               - qcom,sm8250-cci
               - qcom,sm8450-cci
+              - qcom,sm8550-cci
+              - qcom,sm8650-cci
           - const: qcom,msm8996-cci # CCI v2
 
   "#address-cells":
@@ -195,6 +197,24 @@ allOf:
             - const: cpas_ahb
             - const: cci
 
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - qcom,sm8550-cci
+              - qcom,sm8650-cci
+    then:
+      properties:
+        clocks:
+          minItems: 3
+          maxItems: 3
+        clock-names:
+          items:
+            - const: camnoc_axi
+            - const: cpas_ahb
+            - const: cci
+
 additionalProperties: false
 
 examples:

drivers/i2c/busses/Kconfig

@@ -196,6 +196,7 @@ config I2C_ISMT
 config I2C_PIIX4
 	tristate "Intel PIIX4 and compatible (ATI/AMD/Serverworks/Broadcom/SMSC)"
 	depends on PCI && HAS_IOPORT
+	select I2C_SMBUS
 	help
 	  If you say yes to this option, support will be included for the Intel
 	  PIIX4 family of mainboard I2C interfaces.  Specifically, the following

drivers/i2c/busses/i2c-piix4.c

@@ -29,6 +29,7 @@
 #include <linux/stddef.h>
 #include <linux/ioport.h>
 #include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
 #include <linux/slab.h>
 #include <linux/dmi.h>
 #include <linux/acpi.h>
@@ -982,6 +983,14 @@ static int piix4_add_adapter(struct pci_dev *dev, unsigned short smba,
 		return retval;
 	}
 
+	/*
+	 * The AUX bus can not be probed as on some platforms it reports all
+	 * devices present and all reads return "0".
+	 * This would allow the ee1004 to be probed incorrectly.
+	 */
+	if (port == 0)
+		i2c_register_spd(adap);
+
 	*padap = adap;
 	return 0;
 }

drivers/i2c/i2c-smbus.c

@@ -352,18 +352,11 @@ void i2c_register_spd(struct i2c_adapter *adap)
 		return;
 
 	/*
-	 * If we're a child adapter on a muxed segment, then limit slots to 8,
-	 * as this is the max number of SPD EEPROMs that can be addressed per bus.
+	 * The max number of SPD EEPROMs that can be addressed per bus is 8.
+	 * If more slots are present either muxed or multiple busses are
+	 * necessary or the additional slots are ignored.
 	 */
-	if (i2c_parent_is_i2c_adapter(adap)) {
-		slot_count = 8;
-	} else {
-		if (slot_count > 8) {
-			dev_warn(&adap->dev,
-				 "More than 8 memory slots on a single bus, contact i801 maintainer to add missing mux config\n");
-			return;
-		}
-	}
+	slot_count = min(slot_count, 8);
 
 	/*
 	 * Memory types could be found at section 7.18.2 (Memory Device — Type), table 78

drivers/i2c/muxes/i2c-mux-gpio.c

@@ -5,16 +5,17 @@
  * Peter Korsgaard <peter.korsgaard@barco.com>
  */
 
+#include <linux/bits.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/gpio/driver.h>
 #include <linux/i2c.h>
 #include <linux/i2c-mux.h>
+#include <linux/module.h>
 #include <linux/overflow.h>
 #include <linux/platform_data/i2c-mux-gpio.h>
 #include <linux/platform_device.h>
-#include <linux/module.h>
 #include <linux/slab.h>
-#include <linux/bits.h>
-#include <linux/gpio/consumer.h>
-#include <linux/gpio/driver.h>
 
 struct gpiomux {
 	struct i2c_mux_gpio_platform_data data;
@@ -37,6 +38,9 @@ static int i2c_mux_gpio_select(struct i2c_mux_core *muxc, u32 chan)
 
 	i2c_mux_gpio_set(mux, chan);
 
+	if (mux->data.settle_time)
+		fsleep(mux->data.settle_time);
+
 	return 0;
 }
 
@@ -116,6 +120,8 @@ static int i2c_mux_gpio_probe_fw(struct gpiomux *mux,
 	if (device_property_read_u32(dev, "idle-state", &mux->data.idle))
 		mux->data.idle = I2C_MUX_GPIO_NO_IDLE;
 
+	device_property_read_u32(dev, "settle-time-us", &mux->data.settle_time);
+
 	return 0;
 }
 

include/linux/i2c.h

@@ -30,7 +30,6 @@ extern const struct device_type i2c_client_type;
 /* --- General options ------------------------------------------------	*/
 
 struct i2c_msg;
-struct i2c_algorithm;
 struct i2c_adapter;
 struct i2c_client;
 struct i2c_driver;
@@ -512,16 +511,15 @@ i2c_register_board_info(int busnum, struct i2c_board_info const *info,
 #endif /* I2C_BOARDINFO */
 
 /**
- * struct i2c_algorithm - represent I2C transfer method
- * @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.
- * @xfer_atomic: same as @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
+ * struct i2c_algorithm - represent I2C transfer methods
+ * @xfer: Transfer a given number of messages defined by the msgs array via
+ *   the specified adapter.
+ * @xfer_atomic: Same as @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
+ * @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.
@@ -533,8 +531,6 @@ i2c_register_board_info(int busnum, struct i2c_board_info const *info,
  * @reg_slave: deprecated, use @reg_target
  * @unreg_slave: deprecated, use @unreg_target
  *
- *
- * The following structs are for those who like to implement new bus drivers:
  * i2c_algorithm is the interface to a class of hardware solutions which can
  * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
  * to name two of the most common.
@@ -550,9 +546,6 @@ struct i2c_algorithm {
 	 * 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.
-	 *
-	 * xfer should return the number of messages successfully
-	 * processed, or a negative value on error
 	 */
 	union {
 		int (*xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,

include/linux/platform_data/i2c-mux-gpio.h

@@ -19,6 +19,7 @@
  *	position
  * @n_values: Number of multiplexer positions (busses to instantiate)
  * @idle: Bitmask to write to MUX when idle or GPIO_I2CMUX_NO_IDLE if not used
+ * @settle_time: Delay to wait when a new bus is selected
  */
 struct i2c_mux_gpio_platform_data {
 	int parent;
@@ -26,6 +27,7 @@ struct i2c_mux_gpio_platform_data {
 	const unsigned *values;
 	int n_values;
 	unsigned idle;
+	u32 settle_time;
 };
 
 #endif /* _LINUX_I2C_MUX_GPIO_H */