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-rw-r--r--drivers/w1/Kconfig25
-rw-r--r--drivers/w1/Makefile3
-rw-r--r--drivers/w1/w1-gpio.c176
-rw-r--r--drivers/w1/w1-uclass.c240
4 files changed, 444 insertions, 0 deletions
diff --git a/drivers/w1/Kconfig b/drivers/w1/Kconfig
new file mode 100644
index 0000000000..d6e045739d
--- /dev/null
+++ b/drivers/w1/Kconfig
@@ -0,0 +1,25 @@
+#
+# W1 subsystem configuration
+#
+
+menu "1-Wire support"
+
+config W1
+ bool "Enable 1-wire controllers support"
+ default no
+ depends on DM
+ help
+ Support for the Dallas 1-Wire bus.
+
+if W1
+
+config W1_GPIO
+ bool "Enable 1-wire GPIO bitbanging"
+ default no
+ depends on DM_GPIO
+ help
+ Emulate a 1-wire bus using a GPIO.
+
+endif
+
+endmenu
diff --git a/drivers/w1/Makefile b/drivers/w1/Makefile
new file mode 100644
index 0000000000..7fd8697f84
--- /dev/null
+++ b/drivers/w1/Makefile
@@ -0,0 +1,3 @@
+obj-$(CONFIG_W1) += w1-uclass.o
+
+obj-$(CONFIG_W1_GPIO) += w1-gpio.o
diff --git a/drivers/w1/w1-gpio.c b/drivers/w1/w1-gpio.c
new file mode 100644
index 0000000000..5e5d6b3f6c
--- /dev/null
+++ b/drivers/w1/w1-gpio.c
@@ -0,0 +1,176 @@
+/* SPDX-License-Identifier: GPL-2.0+
+ *
+ * Copyright (c) 2015 Free Electrons
+ * Copyright (c) 2015 NextThing Co
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <w1.h>
+
+#include <asm/gpio.h>
+
+#define W1_TIMING_A 6
+#define W1_TIMING_B 64
+#define W1_TIMING_C 60
+#define W1_TIMING_D 10
+#define W1_TIMING_E 9
+#define W1_TIMING_F 55
+#define W1_TIMING_G 0
+#define W1_TIMING_H 480
+#define W1_TIMING_I 70
+#define W1_TIMING_J 410
+
+struct w1_gpio_pdata {
+ struct gpio_desc gpio;
+ u64 search_id;
+};
+
+static bool w1_gpio_read_bit(struct udevice *dev)
+{
+ struct w1_gpio_pdata *pdata = dev_get_platdata(dev);
+ int val;
+
+ dm_gpio_set_dir_flags(&pdata->gpio, GPIOD_IS_OUT);
+ udelay(W1_TIMING_A);
+
+ dm_gpio_set_dir_flags(&pdata->gpio, GPIOD_IS_IN);
+ udelay(W1_TIMING_E);
+
+ val = dm_gpio_get_value(&pdata->gpio);
+ if (val < 0)
+ debug("error in retrieving GPIO value");
+ udelay(W1_TIMING_F);
+
+ return val;
+}
+
+static u8 w1_gpio_read_byte(struct udevice *dev)
+{
+ int i;
+ u8 ret = 0;
+
+ for (i = 0; i < 8; ++i)
+ ret |= (w1_gpio_read_bit(dev) ? 1 : 0) << i;
+
+ return ret;
+}
+
+static void w1_gpio_write_bit(struct udevice *dev, bool bit)
+{
+ struct w1_gpio_pdata *pdata = dev_get_platdata(dev);
+
+ dm_gpio_set_dir_flags(&pdata->gpio, GPIOD_IS_OUT);
+
+ bit ? udelay(W1_TIMING_A) : udelay(W1_TIMING_C);
+
+ dm_gpio_set_value(&pdata->gpio, 1);
+
+ bit ? udelay(W1_TIMING_B) : udelay(W1_TIMING_D);
+}
+
+static void w1_gpio_write_byte(struct udevice *dev, u8 byte)
+{
+ int i;
+
+ for (i = 0; i < 8; ++i)
+ w1_gpio_write_bit(dev, (byte >> i) & 0x1);
+}
+
+static bool w1_gpio_reset(struct udevice *dev)
+{
+ struct w1_gpio_pdata *pdata = dev_get_platdata(dev);
+ int val;
+
+ /* initiate the reset pulse. first we must pull the bus to low */
+ dm_gpio_set_dir_flags(&pdata->gpio, GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE);
+ udelay(W1_TIMING_G);
+
+ dm_gpio_set_value(&pdata->gpio, 0);
+ /* wait for the specified time with the bus kept low */
+ udelay(W1_TIMING_H);
+
+ /* now we must read the presence pulse */
+ dm_gpio_set_dir_flags(&pdata->gpio, GPIOD_IS_IN);
+ udelay(W1_TIMING_I);
+
+ val = dm_gpio_get_value(&pdata->gpio);
+ if (val < 0)
+ debug("error in retrieving GPIO value");
+
+ /* if nobody pulled the bus down , it means nobody is on the bus */
+ if (val != 0)
+ return 1;
+ /* we have the bus pulled down, let's wait for the specified presence time */
+ udelay(W1_TIMING_J);
+
+ /* read again, the other end should leave the bus free */
+ val = dm_gpio_get_value(&pdata->gpio);
+ if (val < 0)
+ debug("error in retrieving GPIO value");
+
+ /* bus is not going up again, so we have an error */
+ if (val != 1)
+ return 1;
+
+ /* all good, presence detected */
+ return 0;
+}
+
+static u8 w1_gpio_triplet(struct udevice *dev, bool bdir)
+{
+ u8 id_bit = w1_gpio_read_bit(dev);
+ u8 comp_bit = w1_gpio_read_bit(dev);
+ u8 retval;
+
+ if (id_bit && comp_bit)
+ return 0x03; /* error */
+
+ if (!id_bit && !comp_bit) {
+ /* Both bits are valid, take the direction given */
+ retval = bdir ? 0x04 : 0;
+ } else {
+ /* Only one bit is valid, take that direction */
+ bdir = id_bit;
+ retval = id_bit ? 0x05 : 0x02;
+ }
+
+ w1_gpio_write_bit(dev, bdir);
+ return retval;
+}
+
+static const struct w1_ops w1_gpio_ops = {
+ .read_byte = w1_gpio_read_byte,
+ .reset = w1_gpio_reset,
+ .triplet = w1_gpio_triplet,
+ .write_byte = w1_gpio_write_byte,
+};
+
+static int w1_gpio_ofdata_to_platdata(struct udevice *dev)
+{
+ struct w1_gpio_pdata *pdata = dev_get_platdata(dev);
+ int ret;
+
+ ret = gpio_request_by_name(dev, "gpios", 0, &pdata->gpio, 0);
+ if (ret < 0)
+ printf("Error claiming GPIO %d\n", ret);
+
+ return ret;
+};
+
+static const struct udevice_id w1_gpio_id[] = {
+ { "w1-gpio", 0 },
+ { },
+};
+
+U_BOOT_DRIVER(w1_gpio_drv) = {
+ .id = UCLASS_W1,
+ .name = "w1_gpio_drv",
+ .of_match = w1_gpio_id,
+ .ofdata_to_platdata = w1_gpio_ofdata_to_platdata,
+ .ops = &w1_gpio_ops,
+ .platdata_auto_alloc_size = sizeof(struct w1_gpio_pdata),
+};
diff --git a/drivers/w1/w1-uclass.c b/drivers/w1/w1-uclass.c
new file mode 100644
index 0000000000..aecf7fec77
--- /dev/null
+++ b/drivers/w1/w1-uclass.c
@@ -0,0 +1,240 @@
+// 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>
+
+#define W1_MATCH_ROM 0x55
+#define W1_SKIP_ROM 0xcc
+#define W1_SEARCH 0xf0
+
+struct w1_bus {
+ u64 search_id;
+};
+
+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);
+ }
+
+ /* last device or error, aborting here */
+ if ((triplet_ret & 0x03) == 0x03)
+ last_device = true;
+
+ 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-eeprom device */
+ w1_eeprom_register_new_device(rn);
+ }
+ }
+
+ 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);
+ !ret;
+ uclass_next_device(&dev), i++) {
+ if (ret) {
+ debug("Cannot find w1 bus %d\n", busnum);
+ return ret;
+ }
+ if (i == busnum) {
+ *busp = dev;
+ return 0;
+ }
+ }
+ return ret;
+}
+
+u8 w1_get_device_family(struct udevice *dev)
+{
+ struct w1_device *w1 = dev_get_parent_platdata(dev);
+
+ return w1->id & 0xff;
+}
+
+int w1_reset_select(struct udevice *dev)
+{
+ struct w1_device *w1 = dev_get_parent_platdata(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_alloc_size = sizeof(struct w1_bus),
+ .post_probe = w1_post_probe,
+#if CONFIG_IS_ENABLED(OF_CONTROL)
+ .post_bind = dm_scan_fdt_dev,
+#endif
+ .per_child_platdata_auto_alloc_size = sizeof(struct w1_device),
+};
generated by cgit (git 2.34.1) at 2025-02-05 00:52:15 +0000