diff options
Diffstat (limited to 'roms/u-boot/drivers/w1/w1-uclass.c')
| -rw-r--r-- | roms/u-boot/drivers/w1/w1-uclass.c | 311 |
1 files changed, 311 insertions, 0 deletions
diff --git a/roms/u-boot/drivers/w1/w1-uclass.c b/roms/u-boot/drivers/w1/w1-uclass.c new file mode 100644 index 000000000..b98927389 --- /dev/null +++ b/roms/u-boot/drivers/w1/w1-uclass.c @@ -0,0 +1,311 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * + * Copyright (c) 2015 Free Electrons + * Copyright (c) 2015 NextThing Co. + * Copyright (c) 2018 Microchip Technology, Inc. + * Copyright (c) 2021 Bootlin + * + * Maxime Ripard <maxime.ripard@free-electrons.com> + * Eugen Hristev <eugen.hristev@microchip.com> + * Kory Maincent <kory.maincent@bootlin.com> + * + */ + +#include <common.h> +#include <dm.h> +#include <log.h> +#include <w1.h> +#include <w1-eeprom.h> + +#include <dm/device-internal.h> + +#define W1_MATCH_ROM 0x55 +#define W1_SKIP_ROM 0xcc +#define W1_SEARCH 0xf0 + +struct w1_bus { + u64 search_id; +}; + +int w1_bus_find_dev(const struct udevice *bus, u64 id, struct udevice +**devp) +{ + struct udevice *dev; + u8 family = id & 0xff; + int ret; + + 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 -ENODEV; + } + + if (dev_get_driver_data(dev) == family) { + *devp = dev; + return 0; + } + } + + return -ENODEV; +} + +int w1_register_new_device(u64 id, struct udevice *bus) +{ + u8 family = id & 0xff; + int n_ents, ret = 0; + struct udevice *dev; + + struct w1_driver_entry *start, *entry; + + start = ll_entry_start(struct w1_driver_entry, w1_driver_entry); + n_ents = ll_entry_count(struct w1_driver_entry, w1_driver_entry); + + for (entry = start; entry != start + n_ents; entry++) { + const u8 *match_family; + const struct driver *drv; + struct w1_device *w1; + + for (match_family = entry->family; match_family; + match_family++) { + if (*match_family != family) + continue; + + ret = w1_bus_find_dev(bus, id, &dev); + + /* If nothing in the device tree, bind a device */ + if (ret == -ENODEV) { + drv = entry->driver; + ret = device_bind(bus, drv, drv->name, + NULL, ofnode_null(), &dev); + if (ret) + return ret; + } + + device_probe(dev); + + w1 = dev_get_parent_plat(dev); + w1->id = id; + + return 0; + } + } + + debug("%s: No matches found: error %d\n", __func__, ret); + + return ret; +} + +static int w1_enumerate(struct udevice *bus) +{ + const struct w1_ops *ops = device_get_ops(bus); + struct w1_bus *w1 = dev_get_uclass_priv(bus); + u64 last_rn, rn = w1->search_id, tmp64; + bool last_device = false; + int search_bit, desc_bit = 64; + int last_zero = -1; + u8 triplet_ret = 0; + int i; + + if (!ops->reset || !ops->write_byte || !ops->triplet) + return -ENOSYS; + + while (!last_device) { + last_rn = rn; + rn = 0; + + /* + * Reset bus and all 1-wire device state machines + * so they can respond to our requests. + * + * Return 0 - device(s) present, 1 - no devices present. + */ + if (ops->reset(bus)) { + debug("%s: No devices present on the wire.\n", + __func__); + break; + } + + /* Start the search */ + ops->write_byte(bus, W1_SEARCH); + for (i = 0; i < 64; ++i) { + /* Determine the direction/search bit */ + if (i == desc_bit) + /* took the 0 path last time, so take the 1 path */ + search_bit = 1; + else if (i > desc_bit) + /* take the 0 path on the next branch */ + search_bit = 0; + else + search_bit = ((last_rn >> i) & 0x1); + + /* Read two bits and write one bit */ + triplet_ret = ops->triplet(bus, search_bit); + + /* quit if no device responded */ + if ((triplet_ret & 0x03) == 0x03) + break; + + /* If both directions were valid, and we took the 0 path... */ + if (triplet_ret == 0) + last_zero = i; + + /* extract the direction taken & update the device number */ + tmp64 = (triplet_ret >> 2); + rn |= (tmp64 << i); + } + + if ((triplet_ret & 0x03) != 0x03) { + if (desc_bit == last_zero || last_zero < 0) { + last_device = 1; + w1->search_id = 0; + } else { + w1->search_id = rn; + } + desc_bit = last_zero; + + debug("%s: Detected new device 0x%llx (family 0x%x)\n", + bus->name, rn, (u8)(rn & 0xff)); + + /* attempt to register as w1 device */ + w1_register_new_device(rn, bus); + } + } + + return 0; +} + +int w1_get_bus(int busnum, struct udevice **busp) +{ + int ret, i = 0; + + struct udevice *dev; + + for (ret = uclass_first_device(UCLASS_W1, &dev); + dev && !ret; + ret = uclass_next_device(&dev), i++) { + if (i == busnum) { + *busp = dev; + return 0; + } + } + + if (!ret) { + debug("Cannot find w1 bus %d\n", busnum); + ret = -ENODEV; + } + + return ret; +} + +u8 w1_get_device_family(struct udevice *dev) +{ + struct w1_device *w1 = dev_get_parent_plat(dev); + + return w1->id & 0xff; +} + +int w1_reset_select(struct udevice *dev) +{ + struct w1_device *w1 = dev_get_parent_plat(dev); + struct udevice *bus = dev_get_parent(dev); + const struct w1_ops *ops = device_get_ops(bus); + int i; + + if (!ops->reset || !ops->write_byte) + return -ENOSYS; + + ops->reset(bus); + + ops->write_byte(bus, W1_MATCH_ROM); + + for (i = 0; i < sizeof(w1->id); i++) + ops->write_byte(bus, (w1->id >> (i * 8)) & 0xff); + + return 0; +} + +int w1_read_byte(struct udevice *dev) +{ + struct udevice *bus = dev_get_parent(dev); + const struct w1_ops *ops = device_get_ops(bus); + + if (!ops->read_byte) + return -ENOSYS; + + return ops->read_byte(bus); +} + +int w1_read_buf(struct udevice *dev, u8 *buf, unsigned int count) +{ + int i, ret; + + for (i = 0; i < count; i++) { + ret = w1_read_byte(dev); + if (ret < 0) + return ret; + + buf[i] = ret & 0xff; + } + + return 0; +} + +int w1_write_byte(struct udevice *dev, u8 byte) +{ + struct udevice *bus = dev_get_parent(dev); + const struct w1_ops *ops = device_get_ops(bus); + + if (!ops->write_byte) + return -ENOSYS; + + ops->write_byte(bus, byte); + + return 0; +} + +static int w1_post_probe(struct udevice *bus) +{ + w1_enumerate(bus); + + return 0; +} + +int w1_init(void) +{ + struct udevice *bus; + struct uclass *uc; + int ret; + + ret = uclass_get(UCLASS_W1, &uc); + if (ret) + return ret; + + uclass_foreach_dev(bus, uc) { + ret = device_probe(bus); + if (ret == -ENODEV) { /* No such device. */ + printf("W1 controller not available.\n"); + continue; + } + + if (ret) { /* Other error. */ + printf("W1 controller probe failed.\n"); + continue; + } + } + return 0; +} + +UCLASS_DRIVER(w1) = { + .name = "w1", + .id = UCLASS_W1, + .flags = DM_UC_FLAG_SEQ_ALIAS, + .per_device_auto = sizeof(struct w1_bus), + .post_probe = w1_post_probe, +#if CONFIG_IS_ENABLED(OF_CONTROL) + .post_bind = dm_scan_fdt_dev, +#endif + .per_child_plat_auto = sizeof(struct w1_device), +}; |