sandbox: i2c: Support i2c emulation with of-platdata

At present the i2c emulators require access to the devicetree, which is
not possible (by design) with of-platdata.

Add a way for drivers to record the of-platdata index of their emulator,
so that we can still find the emulator.

This allows i2c emulation to work with of-platdata.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>

3 files changed, 43 insertions, 2 deletions

diff --git a/drivers/i2c/i2c-emul-uclass.c b/drivers/i2c/i2c-emul-uclass.c
index 9ef4651fa4..7917b63c55 100644
--- a/drivers/i2c/i2c-emul-uclass.c
+++ b/drivers/i2c/i2c-emul-uclass.c
@@ -31,14 +31,27 @@ struct udevice *i2c_emul_get_device(struct udevice *emul)
 	return uc_plat->dev;
 }
 
+void i2c_emul_set_idx(struct udevice *dev, int emul_idx)
+{
+	struct dm_i2c_chip *plat = dev_get_parent_plat(dev);
+
+	plat->emul_idx = emul_idx;
+}
+
 int i2c_emul_find(struct udevice *dev, struct udevice **emulp)
 {
 	struct i2c_emul_uc_plat *uc_plat;
 	struct udevice *emul;
 	int ret;
 
-	ret = uclass_find_device_by_phandle(UCLASS_I2C_EMUL, dev,
-					    "sandbox,emul", &emul);
+	if (!CONFIG_IS_ENABLED(OF_PLATDATA)) {
+		ret = uclass_find_device_by_phandle(UCLASS_I2C_EMUL, dev,
+						    "sandbox,emul", &emul);
+	} else {
+		struct dm_i2c_chip *plat = dev_get_parent_plat(dev);
+
+		ret = device_get_by_ofplat_idx(plat->emul_idx, &emul);
+	}
 	if (ret) {
 		log_err("No emulators for device '%s'\n", dev->name);
 		return ret;
diff --git a/drivers/rtc/sandbox_rtc.c b/drivers/rtc/sandbox_rtc.c
index d0864b1df9..657e5c7be2 100644
--- a/drivers/rtc/sandbox_rtc.c
+++ b/drivers/rtc/sandbox_rtc.c
@@ -79,6 +79,18 @@ struct acpi_ops sandbox_rtc_acpi_ops = {
 };
 #endif
 
+static int sandbox_rtc_bind(struct udevice *dev)
+{
+#if CONFIG_IS_ENABLED(PLATDATA)
+	struct sandbox_i2c_rtc_plat_data *plat = dev_get_plat(dev);
+
+	/* Set up the emul_idx for i2c_emul_find() */
+	i2c_emul_set_idx(dev, plat->dtplat.sandbox_emul->idx);
+#endif
+
+	return 0;
+}
+
 static const struct rtc_ops sandbox_rtc_ops = {
 	.get = sandbox_rtc_get,
 	.set = sandbox_rtc_set,
@@ -97,5 +109,6 @@ U_BOOT_DRIVER(sandbox_rtc) = {
 	.id	= UCLASS_RTC,
 	.of_match = sandbox_rtc_ids,
 	.ops	= &sandbox_rtc_ops,
+	.bind	= sandbox_rtc_bind,
 	ACPI_OPS_PTR(&sandbox_rtc_acpi_ops)
 };
diff --git a/include/i2c.h b/include/i2c.h
index 7ae0c42706..c0fe94c1f3 100644
--- a/include/i2c.h
+++ b/include/i2c.h
@@ -93,6 +93,8 @@ struct udevice;
  *			   datasheet explains it's usage of this addressing
  *			   mode.
  * @emul: Emulator for this chip address (only used for emulation)
+ * @emul_idx: Emulator index, used for of-platdata and set by each i2c chip's
+ *	bind() method. This allows i2c_emul_find() to work with of-platdata.
  */
 struct dm_i2c_chip {
 	uint chip_addr;
@@ -102,6 +104,7 @@ struct dm_i2c_chip {
 #ifdef CONFIG_SANDBOX
 	struct udevice *emul;
 	bool test_mode;
+	int emul_idx;
 #endif
 };
 
@@ -555,6 +558,18 @@ void i2c_dump_msgs(struct i2c_msg *msg, int nmsgs);
 int i2c_emul_find(struct udevice *dev, struct udevice **emulp);
 
 /**
+ * i2c_emul_set_idx() - Set the emulator index for an i2c sandbox device
+ *
+ * With of-platdata we cannot find the emulator using the device tree, so rely
+ * on the bind() method of each i2c driver calling this function to tell us
+ * the of-platdata idx of the emulator
+ *
+ * @dev: i2c device to set the emulator for
+ * @emul_idx: of-platdata index for that emulator
+ */
+void i2c_emul_set_idx(struct udevice *dev, int emul_idx);
+
+/**
  * i2c_emul_get_device() - Find the device being emulated
  *
  * Given an emulator this returns the associated device