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>
This commit is contained in:
Maxime Ripard 2018-09-18 10:35:27 +03:00 committed by Tom Rini
parent e1721ba0e6
commit c924ee25aa
7 changed files with 172 additions and 0 deletions

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@ -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

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@ -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

17
drivers/w1-eeprom/Kconfig Normal file
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@ -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

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@ -0,0 +1,2 @@
obj-$(CONFIG_W1_EEPROM) += w1-eeprom-uclass.o

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@ -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;
}

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@ -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,

33
include/w1-eeprom.h Normal file
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@ -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