i2c: omap: Add support for setting mux

commit b6ef830 upstream.

Some SoCs require muxes in the routing for SDA and SCL lines.
Therefore, add support for setting the mux by reading the mux-states
property from the dt-node.

Signed-off-by: Jayesh Choudhary <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Andi Shyti <[email protected]>
Stable-dep-of: a9503a2 ("i2c: omap: Handle omap_i2c_init() errors in omap_i2c_probe()")
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: jayesh-ti

drivers/i2c/busses/Kconfig

@@ -937,6 +937,7 @@ config I2C_OMAP
 	tristate "OMAP I2C adapter"
 	depends on ARCH_OMAP || ARCH_K3 || COMPILE_TEST
 	default MACH_OMAP_OSK
+	select MULTIPLEXER
 	help
 	  If you say yes to this option, support will be included for the
 	  I2C interface on the Texas Instruments OMAP1/2 family of processors.

drivers/i2c/busses/i2c-omap.c

@@ -24,6 +24,7 @@
 #include <linux/platform_device.h>
 #include <linux/clk.h>
 #include <linux/io.h>
+#include <linux/mux/consumer.h>
 #include <linux/of.h>
 #include <linux/slab.h>
 #include <linux/platform_data/i2c-omap.h>
@@ -211,6 +212,7 @@ struct omap_i2c_dev {
 	u16			syscstate;
 	u16			westate;
 	u16			errata;
+	struct mux_state	*mux_state;
 };
 
 static const u8 reg_map_ip_v1[] = {
@@ -1452,6 +1454,23 @@ omap_i2c_probe(struct platform_device *pdev)
 				       (1000 * omap->speed / 8);
 	}
 
+	if (of_property_read_bool(node, "mux-states")) {
+		struct mux_state *mux_state;
+
+		mux_state = devm_mux_state_get(&pdev->dev, NULL);
+		if (IS_ERR(mux_state)) {
+			r = PTR_ERR(mux_state);
+			dev_dbg(&pdev->dev, "failed to get I2C mux: %d\n", r);
+			goto err_disable_pm;
+		}
+		omap->mux_state = mux_state;
+		r = mux_state_select(omap->mux_state);
+		if (r) {
+			dev_err(&pdev->dev, "failed to select I2C mux: %d\n", r);
+			goto err_disable_pm;
+		}
+	}
+
 	/* reset ASAP, clearing any IRQs */
 	omap_i2c_init(omap);
 
@@ -1511,6 +1530,9 @@ static void omap_i2c_remove(struct platform_device *pdev)
 
 	i2c_del_adapter(&omap->adapter);
 
+	if (omap->mux_state)
+		mux_state_deselect(omap->mux_state);
+
 	ret = pm_runtime_get_sync(&pdev->dev);
 	if (ret < 0)
 		dev_err(omap->dev, "Failed to resume hardware, skip disable\n");