dm: i2c: Add an I2C EEPROM simulator

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@chromium.org>
Acked-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Masahiro Yamada <yamada.m@jp.panasonic.com>

diff --git a/arch/sandbox/include/asm/test.h b/arch/sandbox/include/asm/test.h
new file mode 100644 (file)
index 0000000..25a0c85
--- /dev/null
+++ b/arch/sandbox/include/asm/test.h
@@ -0,0 +1,26 @@
+/*
+ * Test-related constants for sandbox
+ *
+ * Copyright (c) 2014 Google, Inc
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#ifndef __ASM_TEST_H
+#define __ASM_TEST_H
+
+/* The sandbox driver always permits an I2C device with this address */
+#define SANDBOX_I2C_TEST_ADDR  0x59
+
+enum sandbox_i2c_eeprom_test_mode {
+       SIE_TEST_MODE_NONE,
+       /* Permits read/write of only one byte per I2C transaction */
+       SIE_TEST_MODE_SINGLE_BYTE,
+};
+
+void sandbox_i2c_eeprom_set_test_mode(struct udevice *dev,
+                                     enum sandbox_i2c_eeprom_test_mode mode);
+
+void sandbox_i2c_eeprom_set_offset_len(struct udevice *dev, int offset_len);
+
+#endif

diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 2f2e48f..ff02184 100644 (file)
--- 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 (file)
index 0000000..7343445
--- /dev/null
+++ b/drivers/misc/i2c_eeprom_emul.c
@@ -0,0 +1,168 @@
+/*
+ * 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>
+#include <asm/test.h>
+
+#ifdef DEBUG
+#define debug_buffer print_buffer
+#else
+#define debug_buffer(x, ...)
+#endif
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct sandbox_i2c_flash_plat_data {
+       enum sandbox_i2c_eeprom_test_mode test_mode;
+       const char *filename;
+       int offset_len;         /* Length of an offset in bytes */
+       int size;               /* Size of data buffer */
+};
+
+struct sandbox_i2c_flash {
+       uint8_t *data;
+};
+
+void sandbox_i2c_eeprom_set_test_mode(struct udevice *dev,
+                                     enum sandbox_i2c_eeprom_test_mode mode)
+{
+       struct sandbox_i2c_flash_plat_data *plat = dev_get_platdata(dev);
+
+       plat->test_mode = mode;
+}
+
+void sandbox_i2c_eeprom_set_offset_len(struct udevice *dev, int offset_len)
+{
+       struct sandbox_i2c_flash_plat_data *plat = dev_get_platdata(dev);
+
+       plat->offset_len = offset_len;
+}
+
+static int sandbox_i2c_eeprom_xfer(struct udevice *emul, struct i2c_msg *msg,
+                                 int nmsgs)
+{
+       struct sandbox_i2c_flash *priv = dev_get_priv(emul);
+       uint offset = 0;
+
+       debug("\n%s\n", __func__);
+       debug_buffer(0, priv->data, 1, 16, 0);
+       for (; nmsgs > 0; nmsgs--, msg++) {
+               struct sandbox_i2c_flash_plat_data *plat =
+                               dev_get_platdata(emul);
+               int len;
+               u8 *ptr;
+
+               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;
+               }
+               len = msg->len;
+               debug("   %s: msg->len=%d",
+                     msg->flags & I2C_M_RD ? "read" : "write",
+                     msg->len);
+               if (msg->flags & I2C_M_RD) {
+                       if (plat->test_mode == SIE_TEST_MODE_SINGLE_BYTE)
+                               len = 1;
+                       debug(", offset %x, len %x: ", offset, len);
+                       memcpy(msg->buf, priv->data + offset, len);
+                       memset(msg->buf + len, '\xff', msg->len - len);
+                       debug_buffer(0, msg->buf, 1, msg->len, 0);
+               } else if (len >= plat->offset_len) {
+                       int i;
+
+                       ptr = msg->buf;
+                       for (i = 0; i < plat->offset_len; i++, len--)
+                               offset = (offset << 8) | *ptr++;
+                       debug(", set offset %x: ", offset);
+                       debug_buffer(0, msg->buf, 1, msg->len, 0);
+                       if (plat->test_mode == SIE_TEST_MODE_SINGLE_BYTE)
+                               len = min(len, 1);
+
+                       /* For testing, map offsets into our limited buffer */
+                       for (i = 24; i > 0; i -= 8) {
+                               if (offset > (1 << i)) {
+                                       offset = (offset >> i) |
+                                               (offset & ((1 << i) - 1));
+                                       offset += i;
+                               }
+                       }
+                       memcpy(priv->data + offset, ptr, len);
+               }
+       }
+       debug_buffer(0, priv->data, 1, 16, 0);
+
+       return 0;
+}
+
+struct dm_i2c_ops sandbox_i2c_emul_ops = {
+       .xfer = sandbox_i2c_eeprom_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;
+       }
+       plat->test_mode = SIE_TEST_MODE_NONE;
+       plat->offset_len = 1;
+
+       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 int sandbox_i2c_eeprom_remove(struct udevice *dev)
+{
+       struct sandbox_i2c_flash *priv = dev_get_priv(dev);
+
+       free(priv->data);
+
+       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,
+       .remove         = sandbox_i2c_eeprom_remove,
+       .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,
+};