dm: i2c: Add a sandbox I2C driver
This driver includes some test features such as only supporting certain
bus speeds. It passes its I2C traffic through to an emulator.
Acked-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
diff --git a/drivers/i2c/sandbox_i2c.c b/drivers/i2c/sandbox_i2c.c
new file mode 100644
index 0000000..f0e9f51
--- /dev/null
+++ b/drivers/i2c/sandbox_i2c.c
@@ -0,0 +1,111 @@
+/*
+ * Simulate an I2C port
+ *
+ * Copyright (c) 2014 Google, Inc
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <i2c.h>
+#include <asm/test.h>
+#include <dm/lists.h>
+#include <dm/device-internal.h>
+#include <dm/root.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct dm_sandbox_i2c_emul_priv {
+ struct udevice *emul;
+};
+
+static int get_emul(struct udevice *dev, struct udevice **devp,
+ struct dm_i2c_ops **opsp)
+{
+ struct dm_i2c_chip *priv;
+ int ret;
+
+ *devp = NULL;
+ *opsp = NULL;
+ priv = dev_get_parentdata(dev);
+ if (!priv->emul) {
+ ret = dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset,
+ false);
+ if (ret)
+ return ret;
+
+ ret = device_get_child(dev, 0, &priv->emul);
+ if (ret)
+ return ret;
+ }
+ *devp = priv->emul;
+ *opsp = i2c_get_ops(priv->emul);
+
+ return 0;
+}
+
+static int sandbox_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
+ int nmsgs)
+{
+ struct dm_i2c_bus *i2c = bus->uclass_priv;
+ struct dm_i2c_ops *ops;
+ struct udevice *emul, *dev;
+ bool is_read;
+ int ret;
+
+ /* Special test code to return success but with no emulation */
+ if (msg->addr == SANDBOX_I2C_TEST_ADDR)
+ return 0;
+
+ ret = i2c_get_chip(bus, msg->addr, &dev);
+ if (ret)
+ return ret;
+
+ ret = get_emul(dev, &emul, &ops);
+ if (ret)
+ return ret;
+
+ /*
+ * For testing, don't allow writing above 100KHz for writes and
+ * 400KHz for reads
+ */
+ is_read = nmsgs > 1;
+ if (i2c->speed_hz > (is_read ? 400000 : 100000))
+ return -EINVAL;
+ return ops->xfer(emul, msg, nmsgs);
+}
+
+static const struct dm_i2c_ops sandbox_i2c_ops = {
+ .xfer = sandbox_i2c_xfer,
+};
+
+static int sandbox_i2c_child_pre_probe(struct udevice *dev)
+{
+ struct dm_i2c_chip *i2c_chip = dev_get_parentdata(dev);
+
+ /* Ignore our test address */
+ if (i2c_chip->chip_addr == SANDBOX_I2C_TEST_ADDR)
+ return 0;
+ if (dev->of_offset == -1)
+ return 0;
+
+ return i2c_chip_ofdata_to_platdata(gd->fdt_blob, dev->of_offset,
+ i2c_chip);
+}
+
+static const struct udevice_id sandbox_i2c_ids[] = {
+ { .compatible = "sandbox,i2c" },
+ { }
+};
+
+U_BOOT_DRIVER(i2c_sandbox) = {
+ .name = "i2c_sandbox",
+ .id = UCLASS_I2C,
+ .of_match = sandbox_i2c_ids,
+ .per_child_auto_alloc_size = sizeof(struct dm_i2c_chip),
+ .child_pre_probe = sandbox_i2c_child_pre_probe,
+ .ops = &sandbox_i2c_ops,
+};