W1-EEPROM: Add an W1-EEPROM uclass for 1 wire EEPROMs

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@microchip.com: reworked patch]
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>

diff --git a/drivers/Kconfig b/drivers/Kconfig
index 6f91eac8a91195627ccb5c6e7f667fd3b7fa1cfd..e4396b44c4f0c3b3b14ed2df4279e83e853c854a 100644 (file)
--- 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 4ca07c38a064e8d8ba9fd88a4d3cffcce9769591..1d5905fe731ed9b9da04e90de6d874cc3df47f39 100644 (file)
--- 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 (file)
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 (file)
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 (file)
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 fcfc12035170504465da87387305916cb495c337..e6fc3ab92b3c9911edd41d89bd3bbdfdd2320181 100644 (file)
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -94,6 +94,7 @@ 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 (file)
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