[U-Boot] [PATCH v4 04/34] W1-EEPROM: Add an W1-EEPROM uclass for 1 wire EEPROMs

Eugen Hristev
2018-09-18T07:35:27Z

From: Maxime Ripard <maxime.ripard@free-electrons.com>

We might want to access data stored onto one wire EEPROMs.
Create a framework to provide a consistent API.

Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
[eugen.hristev at microchip.com: reworked patch]
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
---
drivers/Kconfig | 2 +
drivers/Makefile | 1 +
drivers/w1-eeprom/Kconfig | 17 +++++
drivers/w1-eeprom/Makefile | 2 +
drivers/w1-eeprom/w1-eeprom-uclass.c | 116 +++++++++++++++++++++++++++++++++++
include/dm/uclass-id.h | 1 +
include/w1-eeprom.h | 33 ++++++++++
7 files changed, 172 insertions(+)
create mode 100644 drivers/w1-eeprom/Kconfig
create mode 100644 drivers/w1-eeprom/Makefile
create mode 100644 drivers/w1-eeprom/w1-eeprom-uclass.c
create mode 100644 include/w1-eeprom.h

diff --git a/drivers/Kconfig b/drivers/Kconfig
index 6f91eac..e4396b4 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -108,6 +108,8 @@ source "drivers/video/Kconfig"

source "drivers/w1/Kconfig"

+source "drivers/w1-eeprom/Kconfig"
+
source "drivers/watchdog/Kconfig"

config PHYS_TO_BUS
diff --git a/drivers/Makefile b/drivers/Makefile
index 4ca07c3..1d5905f 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -106,6 +106,7 @@ obj-y += soc/
obj-y += thermal/
obj-y += axi/
obj-$(CONFIG_W1) += w1/
+obj-$(CONFIG_W1_EEPROM) += w1-eeprom/

obj-$(CONFIG_MACH_PIC32) += ddr/microchip/
endif
diff --git a/drivers/w1-eeprom/Kconfig b/drivers/w1-eeprom/Kconfig
new file mode 100644
index 0000000..d5ddc80
--- /dev/null
+++ b/drivers/w1-eeprom/Kconfig
@@ -0,0 +1,17 @@
+#
+# EEPROM subsystem configuration
+#
+
+menu "1-wire EEPROM support"
+
+config W1_EEPROM
+ bool "Enable support for EEPROMs on 1wire interface"
+ depends on DM
+ help
+ Support for the EEPROMs connected on 1-wire Dallas protocol interface
+
+if W1_EEPROM
+
+endif
+
+endmenu
diff --git a/drivers/w1-eeprom/Makefile b/drivers/w1-eeprom/Makefile
new file mode 100644
index 0000000..b72950e
--- /dev/null
+++ b/drivers/w1-eeprom/Makefile
@@ -0,0 +1,2 @@
+obj-$(CONFIG_W1_EEPROM) += w1-eeprom-uclass.o
+
diff --git a/drivers/w1-eeprom/w1-eeprom-uclass.c b/drivers/w1-eeprom/w1-eeprom-uclass.c
new file mode 100644
index 0000000..7b05793
--- /dev/null
+++ b/drivers/w1-eeprom/w1-eeprom-uclass.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *
+ * Copyright (c) 2015 Free Electrons
+ * Copyright (c) 2015 NextThing Co.
+ * Copyright (c) 2018 Microchip Technology, Inc.
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ * Eugen Hristev <eugen.hristev@microchip.com>
+ *
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <w1.h>
+#include <w1-eeprom.h>
+
+#include <dm/device-internal.h>
+
+int w1_eeprom_read_buf(struct udevice *dev, unsigned int offset,
+ u8 *buf, unsigned int count)
+{
+ const struct w1_eeprom_ops *ops = device_get_ops(dev);
+ u64 id = 0;
+ int ret;
+
+ if (!ops->read_buf)
+ return -ENOSYS;
+
+ ret = w1_eeprom_get_id(dev, &id);
+ if (ret)
+ return ret;
+ if (!id)
+ return -ENODEV;
+
+ return ops->read_buf(dev, offset, buf, count);
+}
+
+int w1_eeprom_register_new_device(u64 id)
+{
+ u8 family = id & 0xff;
+ int ret;
+ struct udevice *dev;
+
+ for (ret = uclass_first_device(UCLASS_W1_EEPROM, &dev);
+ !ret && dev;
+ uclass_next_device(&dev)) {
+ if (ret || !dev) {
+ debug("cannot find w1 eeprom dev\n");
+ return ret;
+ }
+ if (dev_get_driver_data(dev) == family) {
+ struct w1_device *w1;
+
+ w1 = dev_get_parent_platdata(dev);
+ if (w1->id) /* device already in use */
+ continue;
+ w1->id = id;
+ debug("%s: Match found: %s:%s %llx\n", __func__,
+ dev->name, dev->driver->name, id);
+ return 0;
+ }
+ }
+
+ debug("%s: No matches found: error %d\n", __func__, ret);
+
+ return ret;
+}
+
+int w1_eeprom_get_id(struct udevice *dev, u64 *id)
+{
+ struct w1_device *w1 = dev_get_parent_platdata(dev);
+
+ if (!w1)
+ return -ENODEV;
+ *id = w1->id;
+
+ return 0;
+}
+
+UCLASS_DRIVER(w1_eeprom) = {
+ .name = "w1_eeprom",
+ .id = UCLASS_W1_EEPROM,
+ .flags = DM_UC_FLAG_SEQ_ALIAS,
+#if CONFIG_IS_ENABLED(OF_CONTROL)
+ .post_bind = dm_scan_fdt_dev,
+#endif
+};
+
+int w1_eeprom_dm_init(void)
+{
+ struct udevice *dev;
+ struct uclass *uc;
+ int ret;
+
+ ret = uclass_get(UCLASS_W1_EEPROM, &uc);
+ if (ret) {
+ debug("W1_EEPROM uclass not available\n");
+ return ret;
+ }
+
+ uclass_foreach_dev(dev, uc) {
+ ret = device_probe(dev);
+ if (ret == -ENODEV) { /* No such device. */
+ debug("W1_EEPROM not available.\n");
+ continue;
+ }
+
+ if (ret) { /* Other error. */
+ printf("W1_EEPROM probe failed, error %d\n", ret);
+ continue;
+ }
+ }
+
+ return 0;
+}
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index fa72afb..71adf7e 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -93,6 +93,7 @@ enum uclass_id {
UCLASS_VIDEO_BRIDGE, /* Video bridge, e.g. DisplayPort to LVDS */
UCLASS_VIDEO_CONSOLE, /* Text console driver for video device */
UCLASS_W1, /* Dallas 1-Wire bus */
+ UCLASS_W1_EEPROM, /* one-wire EEPROMs */
UCLASS_WDT, /* Watchdot Timer driver */

UCLASS_COUNT,
diff --git a/include/w1-eeprom.h b/include/w1-eeprom.h
new file mode 100644
index 0000000..2233736
--- /dev/null
+++ b/include/w1-eeprom.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0+
+ *
+ * Copyright (c) 2015 Free Electrons
+ * Copyright (c) 2015 NextThing Co
+ * Copyright (c) 2018 Microchip Technology, Inc.
+ *
+ */
+
+#ifndef __W1_EEPROM_H
+#define __W1_EEPROM_H
+
+struct udevice;
+
+struct w1_eeprom_ops {
+ /*
+ * Reads a buff from the given EEPROM memory, starting at
+ * given offset and place the results into the given buffer.
+ * Should read given count of bytes.
+ * Should return 0 on success, and normal error.h on error
+ */
+ int (*read_buf)(struct udevice *dev, unsigned int offset,
+ u8 *buf, unsigned int count);
+};
+
+int w1_eeprom_read_buf(struct udevice *dev, unsigned int offset,
+ u8 *buf, unsigned int count);
+
+int w1_eeprom_dm_init(void);
+
+int w1_eeprom_register_new_device(u64 id);
+
+int w1_eeprom_get_id(struct udevice *dev, u64 *id);
+#endif
--
2.7.4