Merge branch 'i2c/for-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:
 "I2C has for you two new drivers (Tegra BPMP and STM32F4), interrupt
  support for pca954x muxes, and a bunch of driver bugfixes and
  improvements. Nothing really special this cycle.

  A few commits have been added to my tree just recently. Those are the
  Tegra BPMP driver and a few straightforward bugfixes or cleanups which
  I prefer to have upstream rather soonish. The rest had proper
  linux-next exposure"

* 'i2c/for-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (25 commits)
  i2c: thunderx: Replace pci_enable_msix()
  i2c: exynos5: fix arbitration lost handling
  i2c: exynos5: disable fifo-almost-empty irq signal when necessary
  i2c: at91: ensure state is restored after suspending
  i2c: bcm2835: Avoid possible NULL ptr dereference
  i2c: Add Tegra BPMP I2C proxy driver
  dt-bindings: Add Tegra186 BPMP I2C binding
  misc: eeprom: at24: use device_property_*() functions instead of of_get_property()
  i2c: mux: pca954x: Add interrupt controller support
  dt: bindings: i2c-mux-pca954x: Add documentation for interrupt controller
  i2c: mux: pca954x: Add missing pca9542 definition to chip_desc
  i2c: riic: correctly finish transfers
  i2c: i801: Add support for Intel Gemini Lake
  i2c: mux: pca9541: Export OF device ID table as module aliases
  i2c: mux: pca954x: Export OF device ID table as module aliases
  i2c: mux: mlxcpld: remove unused including <linux/version.h>
  i2c: busses: constify i2c_algorithm structures
  i2c: i2c-mux-gpio: rename i2c-gpio-mux to i2c-mux-gpio
  i2c: sh_mobile: document support for r8a7796 (R-Car M3-W)
  i2c: i2c-cros-ec-tunnel: Reduce logging noise
  ...

1 files changed, 33 insertions, 0 deletions

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index bfb6ba7cac00..d2402bbf6729 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -3705,6 +3705,39 @@ int i2c_slave_unregister(struct i2c_client *client)
 	return ret;
 }
 EXPORT_SYMBOL_GPL(i2c_slave_unregister);
+
+/**
+ * i2c_detect_slave_mode - detect operation mode
+ * @dev: The device owning the bus
+ *
+ * This checks the device nodes for an I2C slave by checking the address
+ * used in the reg property. If the address match the I2C_OWN_SLAVE_ADDRESS
+ * flag this means the device is configured to act as a I2C slave and it will
+ * be listening at that address.
+ *
+ * Returns true if an I2C own slave address is detected, otherwise returns
+ * false.
+ */
+bool i2c_detect_slave_mode(struct device *dev)
+{
+	if (IS_BUILTIN(CONFIG_OF) && dev->of_node) {
+		struct device_node *child;
+		u32 reg;
+
+		for_each_child_of_node(dev->of_node, child) {
+			of_property_read_u32(child, "reg", &reg);
+			if (reg & I2C_OWN_SLAVE_ADDRESS) {
+				of_node_put(child);
+				return true;
+			}
+		}
+	} else if (IS_BUILTIN(CONFIG_ACPI) && ACPI_HANDLE(dev)) {
+		dev_dbg(dev, "ACPI slave is not supported yet\n");
+	}
+	return false;
+}
+EXPORT_SYMBOL_GPL(i2c_detect_slave_mode);
+
 #endif
 
 MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");