[U-Boot] [PATCH 1/4 v3] net: add MDIO_MUX DM class
Alexandru Marginean
alexandru.marginean at nxp.com
Tue Jun 18 14:58:35 UTC 2019
Adds a class for MDIO MUXes, which control access to a series of
downstream child MDIOs.
MDIO MUX drivers are required to implement a select function used to switch
between child buses.
MUX children are registered as MDIO buses and they can be used just like
regular MDIOs.
Signed-off-by: Alex Marginean <alexm.osslist at gmail.com>
---
Changes in v2:
- no change
Changes in v3:
- no change, just fighting with the email server
drivers/net/Kconfig | 12 +++
include/dm/uclass-id.h | 1 +
include/miiphy.h | 20 ++++
net/Makefile | 1 +
net/mdio-mux-uclass.c | 232 +++++++++++++++++++++++++++++++++++++++++
5 files changed, 266 insertions(+)
create mode 100644 net/mdio-mux-uclass.c
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 635f8d72c2..0dc26ac254 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -24,6 +24,18 @@ config DM_MDIO
This is currently implemented in net/mdio-uclass.c
Look in include/miiphy.h for details.
+config DM_MDIO_MUX
+ bool "Enable Driver Model for MDIO MUX devices"
+ depends on DM_MDIO
+ help
+ Enable driver model for MDIO MUX devices
+
+ Adds UCLASS_MDIO_MUX DM class supporting MDIO MUXes. Useful for
+ systems that support DM_MDIO and integrate one or multiple muxes on
+ the MDIO bus.
+ This is currently implemented in net/mdio-mux-uclass.c
+ Look in include/miiphy.h for details.
+
config MDIO_SANDBOX
depends on DM_MDIO && SANDBOX
default y
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 90667e62cf..b859a9ec04 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -59,6 +59,7 @@ enum uclass_id {
UCLASS_MAILBOX, /* Mailbox controller */
UCLASS_MASS_STORAGE, /* Mass storage device */
UCLASS_MDIO, /* MDIO bus */
+ UCLASS_MDIO_MUX, /* MDIO MUX/switch */
UCLASS_MISC, /* Miscellaneous device */
UCLASS_MMC, /* SD / MMC card or chip */
UCLASS_MOD_EXP, /* RSA Mod Exp device */
diff --git a/include/miiphy.h b/include/miiphy.h
index e6dd441983..9b97d09f18 100644
--- a/include/miiphy.h
+++ b/include/miiphy.h
@@ -167,4 +167,24 @@ struct phy_device *dm_mdio_phy_connect(struct udevice *dev, int addr,
#endif
+#ifdef CONFIG_DM_MDIO_MUX
+
+/* indicates none of the child buses is selected */
+#define MDIO_MUX_SELECT_NONE -1
+
+/**
+ * struct mdio_mux_ops - MDIO MUX operations
+ *
+ * @select: Selects a child bus
+ * @deselect: Clean up selection. Optional, can be NULL
+ */
+struct mdio_mux_ops {
+ int (*select)(struct udevice *mux, int cur, int sel);
+ int (*deselect)(struct udevice *mux, int sel);
+};
+
+#define mdio_mux_get_ops(dev) ((struct mdio_mux_ops *)(dev)->driver->ops)
+
+#endif
+
#endif
diff --git a/net/Makefile b/net/Makefile
index 6251ff3991..826544f05f 100644
--- a/net/Makefile
+++ b/net/Makefile
@@ -16,6 +16,7 @@ else
obj-$(CONFIG_NET) += eth_legacy.o
endif
obj-$(CONFIG_DM_MDIO) += mdio-uclass.o
+obj-$(CONFIG_DM_MDIO_MUX) += mdio-mux-uclass.o
obj-$(CONFIG_NET) += eth_common.o
obj-$(CONFIG_CMD_LINK_LOCAL) += link_local.o
obj-$(CONFIG_NET) += net.o
diff --git a/net/mdio-mux-uclass.c b/net/mdio-mux-uclass.c
new file mode 100644
index 0000000000..e3fe12a531
--- /dev/null
+++ b/net/mdio-mux-uclass.c
@@ -0,0 +1,232 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2019
+ * Alex Marginean, NXP
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <miiphy.h>
+#include <dm/device-internal.h>
+#include <dm/uclass-internal.h>
+#include <dm/lists.h>
+
+#define MDIO_MUX_CHILD_DRV_NAME "mdio-mux-bus-drv"
+
+/**
+ * struct mdio_mux_perdev_priv - Per-device class data for MDIO MUX DM
+ *
+ * @parent_mdio: Parent DM MDIO device, this is called for actual MDIO I/O after
+ * setting up the mux. Typically this is a real MDIO device,
+ * unless there are cascaded muxes.
+ * @selected: Current child bus selection. Defaults to -1
+ */
+struct mdio_mux_perdev_priv {
+ struct udevice *mdio_parent;
+ int selected;
+};
+
+/*
+ * This source file uses three types of devices, as follows:
+ * - mux is the hardware MDIO MUX which selects between the existing child MDIO
+ * buses, this is the device relevant for MDIO MUX class of drivers.
+ * - ch is a child MDIO bus, this is just a representation of an mux selection,
+ * not a real piece of hardware.
+ * - mdio_parent is the actual MDIO bus called to perform reads/writes after
+ * the MUX is configured. Typically this is a real MDIO device, unless there
+ * are cascaded muxes.
+ */
+
+/**
+ * struct mdio_mux_ch_data - Per-device data for child MDIOs
+ *
+ * @sel: Selection value used by the MDIO MUX to access this child MDIO bus
+ */
+struct mdio_mux_ch_data {
+ int sel;
+};
+
+static struct udevice *mmux_get_parent_mdio(struct udevice *mux)
+{
+ struct mdio_mux_perdev_priv *pdata = dev_get_uclass_priv(mux);
+
+ return pdata->mdio_parent;
+}
+
+static struct mdio_ops *mmux_get_mdio_parent_ops(struct udevice *mux)
+{
+ return mdio_get_ops(mmux_get_parent_mdio(mux));
+}
+
+/* call driver select function before performing MDIO r/w */
+static int mmux_change_sel(struct udevice *ch, bool sel)
+{
+ struct udevice *mux = ch->parent;
+ struct mdio_mux_perdev_priv *priv = dev_get_uclass_priv(mux);
+ struct mdio_mux_ops *ops = mdio_mux_get_ops(mux);
+ struct mdio_mux_ch_data *ch_data = dev_get_parent_platdata(ch);
+ int err = 0;
+
+ if (sel) {
+ err = ops->select(mux, priv->selected, ch_data->sel);
+ if (err)
+ return err;
+
+ priv->selected = ch_data->sel;
+ } else {
+ if (ops->deselect) {
+ ops->deselect(mux, ch_data->sel);
+ priv->selected = MDIO_MUX_SELECT_NONE;
+ }
+ }
+
+ return 0;
+}
+
+/* Read wrapper, sets up the mux before issuing a read on parent MDIO bus */
+static int mmux_read(struct udevice *ch, int addr, int devad,
+ int reg)
+{
+ struct udevice *mux = ch->parent;
+ struct udevice *parent_mdio = mmux_get_parent_mdio(mux);
+ struct mdio_ops *parent_ops = mmux_get_mdio_parent_ops(mux);
+ int err;
+
+ err = mmux_change_sel(ch, true);
+ if (err)
+ return err;
+
+ err = parent_ops->read(parent_mdio, addr, devad, reg);
+ mmux_change_sel(ch, false);
+
+ return err;
+}
+
+/* Write wrapper, sets up the mux before issuing a write on parent MDIO bus */
+static int mmux_write(struct udevice *ch, int addr, int devad,
+ int reg, u16 val)
+{
+ struct udevice *mux = ch->parent;
+ struct udevice *parent_mdio = mmux_get_parent_mdio(mux);
+ struct mdio_ops *parent_ops = mmux_get_mdio_parent_ops(mux);
+ int err;
+
+ err = mmux_change_sel(ch, true);
+ if (err)
+ return err;
+
+ err = parent_ops->write(parent_mdio, addr, devad, reg, val);
+ mmux_change_sel(ch, false);
+
+ return err;
+}
+
+/* Reset wrapper, sets up the mux before issuing a reset on parent MDIO bus */
+static int mmux_reset(struct udevice *ch)
+{
+ struct udevice *mux = ch->parent;
+ struct udevice *parent_mdio = mmux_get_parent_mdio(mux);
+ struct mdio_ops *parent_ops = mmux_get_mdio_parent_ops(mux);
+ int err;
+
+ /* reset is optional, if it's not implemented just exit */
+ if (!parent_ops->reset)
+ return 0;
+
+ err = mmux_change_sel(ch, true);
+ if (err)
+ return err;
+
+ err = parent_ops->reset(parent_mdio);
+ mmux_change_sel(ch, false);
+
+ return err;
+}
+
+/* Picks up the mux selection value for each child */
+static int dm_mdio_mux_child_post_bind(struct udevice *ch)
+{
+ struct mdio_mux_ch_data *ch_data = dev_get_parent_platdata(ch);
+
+ ch_data->sel = dev_read_u32_default(ch, "reg", MDIO_MUX_SELECT_NONE);
+
+ if (ch_data->sel == MDIO_MUX_SELECT_NONE)
+ return -EINVAL;
+
+ return 0;
+}
+
+/* Explicitly bind child MDIOs after binding the mux */
+static int dm_mdio_mux_post_bind(struct udevice *mux)
+{
+ ofnode ch_node;
+ int err, first_err = 0;
+
+ if (!ofnode_valid(mux->node)) {
+ debug("%s: no mux node found, no child MDIO busses set up\n",
+ __func__);
+ return 0;
+ }
+
+ /*
+ * we're going by Linux bindings so the child nodes do not have
+ * compatible strings. We're going through them here and binding to
+ * them.
+ */
+ dev_for_each_subnode(ch_node, mux) {
+ struct udevice *ch_dev;
+ const char *ch_name;
+
+ ch_name = ofnode_get_name(ch_node);
+
+ err = device_bind_driver_to_node(mux, MDIO_MUX_CHILD_DRV_NAME,
+ ch_name, ch_node, &ch_dev);
+ /* try to bind all, but keep 1st error */
+ if (err && !first_err)
+ first_err = err;
+ }
+
+ return first_err;
+}
+
+/* Get a reference to the parent MDIO bus, it should be bound by now */
+static int dm_mdio_mux_post_probe(struct udevice *mux)
+{
+ struct mdio_mux_perdev_priv *priv = dev_get_uclass_priv(mux);
+ int err;
+
+ priv->selected = MDIO_MUX_SELECT_NONE;
+
+ /* pick up mdio parent from device tree */
+ err = uclass_get_device_by_phandle(UCLASS_MDIO, mux, "mdio-parent-bus",
+ &priv->mdio_parent);
+ if (err) {
+ debug("%s: didn't find mdio-parent-bus\n", __func__);
+ return err;
+ }
+
+ return 0;
+}
+
+const struct mdio_ops mmux_child_mdio_ops = {
+ .read = mmux_read,
+ .write = mmux_write,
+ .reset = mmux_reset,
+};
+
+/* MDIO class driver used for MUX child MDIO buses */
+U_BOOT_DRIVER(mdio_mux_child) = {
+ .name = MDIO_MUX_CHILD_DRV_NAME,
+ .id = UCLASS_MDIO,
+ .ops = &mmux_child_mdio_ops,
+};
+
+UCLASS_DRIVER(mdio_mux) = {
+ .id = UCLASS_MDIO_MUX,
+ .name = "mdio-mux",
+ .child_post_bind = dm_mdio_mux_child_post_bind,
+ .post_bind = dm_mdio_mux_post_bind,
+ .post_probe = dm_mdio_mux_post_probe,
+ .per_device_auto_alloc_size = sizeof(struct mdio_mux_perdev_priv),
+ .per_child_platdata_auto_alloc_size = sizeof(struct mdio_mux_ch_data),
+};
--
2.17.1
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