[U-Boot] [PATCH v6 05/11] dm: i2c: Add an I2C EEPROM simulator
Simon Glass
sjg at chromium.org
Wed Dec 10 16:55:51 CET 2014
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>
Acked-by: Heiko Schocher <hs at denx.de>
---
Changes in v6:
- Drop the probe_chip() method which is not needed
Changes in v5: None
Changes in v4:
- Add a probe_chip() method for the eeprom
- Add a remove() method for the eeprom
- Add an eeprom test mode
- Add eeprom debugging output
- Add support for eeprom offset length
Changes in v3:
- Update emulator for new uclass interface
Changes in v2: None
arch/sandbox/include/asm/test.h | 26 +++++++
drivers/misc/Makefile | 3 +
drivers/misc/i2c_eeprom_emul.c | 168 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 197 insertions(+)
create mode 100644 arch/sandbox/include/asm/test.h
create mode 100644 drivers/misc/i2c_eeprom_emul.c
diff --git a/arch/sandbox/include/asm/test.h b/arch/sandbox/include/asm/test.h
new file mode 100644
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
--- 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..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,
+};
--
2.2.0.rc0.207.ga3a616c
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