[U-Boot] [PATCH v3 05/10] dm: i2c: Add an I2C EEPROM simulator

[Simon Glass]

To enable testing of I2C, add a simple I2C EEPROM simulator for sandbox.
It supports reading and writing from a small data store.

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

Changes in v3:
- Update emulator for new uclass interface

Changes in v2: None

 drivers/misc/Makefile          |   3 ++
 drivers/misc/i2c_eeprom_emul.c | 108 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 111 insertions(+)
 create mode 100644 drivers/misc/i2c_eeprom_emul.c

diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 2f2e48f..ff02184 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -20,6 +20,9 @@ obj-$(CONFIG_MXC_OCOTP) += mxc_ocotp.o
 obj-$(CONFIG_MXS_OCOTP) += mxs_ocotp.o
 obj-$(CONFIG_NS87308) += ns87308.o
 obj-$(CONFIG_PDSP188x) += pdsp188x.o
+ifdef CONFIG_DM_I2C
+obj-$(CONFIG_SANDBOX) += i2c_eeprom_emul.o
+endif
 obj-$(CONFIG_STATUS_LED) += status_led.o
 obj-$(CONFIG_TWL4030_LED) += twl4030_led.o
 obj-$(CONFIG_FSL_IFC) += fsl_ifc.o
diff --git a/drivers/misc/i2c_eeprom_emul.c b/drivers/misc/i2c_eeprom_emul.c
new file mode 100644
index 0000000..4cdf442
--- /dev/null
+++ b/drivers/misc/i2c_eeprom_emul.c
@@ -0,0 +1,108 @@
+/*
+ * Simulate an I2C eeprom
+ *
+ * Copyright (c) 2014 Google, Inc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <fdtdec.h>
+#include <i2c.h>
+#include <malloc.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct sandbox_i2c_flash_plat_data {
+	const char *filename;
+	int size;
+};
+
+struct sandbox_i2c_flash {
+	uint8_t *data;
+};
+
+static int sandbox_i2c_eprom_xfer(struct udevice *emul, struct i2c_msg *msg,
+				  int nmsgs)
+{
+	int offset = 0;
+
+	/* Always let probe succeed */
+	if (nmsgs == 1 && msg->len == 1) {
+		printf("%s: Detected probe\n", __func__);
+		return 0;
+	}
+
+	for (; nmsgs > 0; nmsgs--, msg++) {
+		struct sandbox_i2c_flash_plat_data *plat =
+				dev_get_platdata(emul);
+		struct sandbox_i2c_flash *priv = dev_get_priv(emul);
+
+		if (!plat->size)
+			return -ENODEV;
+		if (msg->addr + msg->len > plat->size) {
+			debug("%s: Address %x, len %x is outside range 0..%x\n",
+			      __func__, msg->addr, msg->len, plat->size);
+			return -EINVAL;
+		}
+		if (msg->flags & I2C_M_RD) {
+			memcpy(msg->buf, priv->data + offset, msg->len);
+		} else {
+			offset = *msg->buf;
+			memcpy(priv->data + offset, msg->buf + 1,
+			       msg->len - 1);
+		}
+	}
+
+	return 0;
+}
+
+struct dm_i2c_ops sandbox_i2c_emul_ops = {
+	.xfer = sandbox_i2c_eprom_xfer,
+};
+
+static int sandbox_i2c_eeprom_ofdata_to_platdata(struct udevice *dev)
+{
+	struct sandbox_i2c_flash_plat_data *plat = dev_get_platdata(dev);
+
+	plat->size = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
+				    "sandbox,size", 32);
+	plat->filename = fdt_getprop(gd->fdt_blob, dev->of_offset,
+				     "sandbox,filename", NULL);
+	if (!plat->filename) {
+		debug("%s: No filename for device '%s'\n", __func__,
+		      dev->name);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int sandbox_i2c_eeprom_probe(struct udevice *dev)
+{
+	struct sandbox_i2c_flash_plat_data *plat = dev_get_platdata(dev);
+	struct sandbox_i2c_flash *priv = dev_get_priv(dev);
+
+	priv->data = calloc(1, plat->size);
+	if (!priv->data)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static const struct udevice_id sandbox_i2c_ids[] = {
+	{ .compatible = "sandbox,i2c-eeprom" },
+	{ }
+};
+
+U_BOOT_DRIVER(sandbox_i2c_emul) = {
+	.name		= "sandbox_i2c_eeprom_emul",
+	.id		= UCLASS_I2C_EMUL,
+	.of_match	= sandbox_i2c_ids,
+	.ofdata_to_platdata = sandbox_i2c_eeprom_ofdata_to_platdata,
+	.probe		= sandbox_i2c_eeprom_probe,
+	.priv_auto_alloc_size = sizeof(struct sandbox_i2c_flash),
+	.platdata_auto_alloc_size = sizeof(struct sandbox_i2c_flash_plat_data),
+	.ops		= &sandbox_i2c_emul_ops,
+};
-- 
2.1.0.rc2.206.gedb03e5