[U-Boot] [RFC PATCH 06/12] dm: i2c: Add a sandbox I2C driver

[Simon Glass]

This driver includes some test features such as only supporting certain
bus speeds. It passes its I2C traffic through to an emulator.

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

 drivers/i2c/Makefile      |   2 +-
 drivers/i2c/sandbox_i2c.c | 148 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 149 insertions(+), 1 deletion(-)
 create mode 100644 drivers/i2c/sandbox_i2c.c

diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
index 10edea6..ea18228 100644
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -27,7 +27,7 @@ obj-$(CONFIG_SYS_I2C_OMAP34XX) += omap24xx_i2c.o
 obj-$(CONFIG_SYS_I2C_PPC4XX) += ppc4xx_i2c.o
 obj-$(CONFIG_SYS_I2C_RCAR) += rcar_i2c.o
 obj-$(CONFIG_SYS_I2C_S3C24X0) += s3c24x0_i2c.o
-obj-$(CONFIG_SYS_I2C_SANDBOX) += i2c-emul-uclass.o
+obj-$(CONFIG_SYS_I2C_SANDBOX) += sandbox_i2c.o i2c-emul-uclass.o
 obj-$(CONFIG_SYS_I2C_SH) += sh_i2c.o
 obj-$(CONFIG_SYS_I2C_SOFT) += soft_i2c.o
 obj-$(CONFIG_SYS_I2C_TEGRA) += tegra_i2c.o
diff --git a/drivers/i2c/sandbox_i2c.c b/drivers/i2c/sandbox_i2c.c
new file mode 100644
index 0000000..3beb0f9
--- /dev/null
+++ b/drivers/i2c/sandbox_i2c.c
@@ -0,0 +1,148 @@
+/*
+ * 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 <dm/lists.h>
+#include <dm/device-internal.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct dm_sandbox_i2c_emul_priv {
+	struct udevice *emul;
+};
+
+static int get_emul(struct udevice *bus, uint chip_addr, struct udevice **devp,
+		    struct dm_i2c_ops **opsp)
+{
+	const void *blob = gd->fdt_blob;
+	struct dm_i2c_chip *priv;
+	struct udevice *dev;
+	int ret;
+
+	ret = i2c_get_chip(bus, chip_addr, &dev);
+	if (ret)
+		return ret;
+	priv = dev_get_parentdata(dev);
+	if (!priv->emul) {
+		int node;
+
+		debug("Scanning i2c bus '%s' for devices\n", dev->name);
+		for (node = fdt_first_subnode(blob, dev->of_offset);
+			node >= 0;
+			node = fdt_next_subnode(blob, node)) {
+			int ret;
+
+			ret = lists_bind_fdt(dev, blob, node, &priv->emul);
+			if (ret)
+				return ret;
+			debug("Found emul '%s' for i2c device '%s'\n",
+			      priv->emul->name, dev->name);
+			break;
+		}
+	}
+
+	if (!priv->emul)
+		return -ENODEV;
+	ret = device_probe(priv->emul);
+	if (ret)
+		return ret;
+	*devp = priv->emul;
+	*opsp = i2c_get_ops(priv->emul);
+
+	return 0;
+}
+
+static int sandbox_i2c_probe_chip(struct udevice *bus, uint chip_addr)
+{
+	struct dm_i2c_ops *ops;
+	struct udevice *emul;
+	int ret;
+
+	ret = get_emul(bus, chip_addr, &emul, &ops);
+	if (ret)
+		return ret;
+
+	return ops->probe(emul, chip_addr);
+}
+
+static int sandbox_i2c_read(struct udevice *bus, uint chip_addr, uint addr,
+			    uint alen, uint8_t *buffer, int len)
+{
+	struct dm_i2c_bus *i2c = bus->uclass_priv;
+	struct dm_i2c_ops *ops;
+	struct udevice *emul;
+	int ret;
+
+	ret = get_emul(bus, chip_addr, &emul, &ops);
+	if (ret)
+		return ret;
+
+	/* For testing, don't allow reading above 400KHz */
+	if (i2c->speed_hz > 400000 || alen != 1)
+		return -EINVAL;
+	return ops->read(emul, chip_addr, addr, alen, buffer, len);
+}
+
+static int sandbox_i2c_write(struct udevice *bus, uint chip_addr, uint addr,
+			     uint alen, const uint8_t *buffer, int len)
+{
+	struct dm_i2c_bus *i2c = bus->uclass_priv;
+	struct dm_i2c_ops *ops;
+	struct udevice *emul;
+	int ret;
+
+	ret = get_emul(bus, chip_addr, &emul, &ops);
+	if (ret)
+		return ret;
+
+	/* For testing, don't allow writing above 100KHz */
+	if (i2c->speed_hz > 100000 || alen != 1)
+		return -EINVAL;
+	return ops->write(emul, chip_addr, addr, alen, buffer, len);
+}
+
+static int sandbox_i2c_set_addr_len(struct udevice *dev, uint addr_len)
+{
+	if (addr_len == 3)
+		return -EINVAL;
+
+	return 0;
+}
+
+static const struct dm_i2c_ops sandbox_i2c_ops = {
+	.probe		= sandbox_i2c_probe_chip,
+	.read		= sandbox_i2c_read,
+	.write		= sandbox_i2c_write,
+	.set_addr_len	= sandbox_i2c_set_addr_len,
+};
+
+static int sandbox_i2c_child_pre_probe(struct udevice *dev)
+{
+	struct dm_i2c_chip *i2c_chip = dev_get_parentdata(dev);
+
+	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,
+};
-- 
2.1.0.rc2.206.gedb03e5