[RFC v1 net-next 8/8] net: dsa: ocelot: add external ocelot switch control

[Colin Foster <colin.foster@in-advantage.com>]

Add control of an external VSC7512 chip by way of the ocelot-mfd interface.

Currently the four copper phy ports are fully functional. Communication to
external phys is also functional, but the SGMII / QSGMII interfaces are
currently non-functional.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
---

v1 from previous RFC:
    * Remove unnecessary byteorder and kconfig header includes.
    * Create OCELOT_EXT_PORT_MODE_SERDES macro to match vsc9959.
    * Utilize readx_poll_timeout for SYS_RESET_CFG_MEM_INIT.
    * *_io_res struct arrays have been moved to the MFD files.
    * Changes to utilize phylink_generic_validate() have been squashed.
    * dev_err_probe() is used in the probe function.
    * Make ocelot_ext_switch_of_match static.
    * Relocate ocelot_ext_ops structure to be next to vsc7512_info, to
      match what was done in other felix drivers.
    * Utilize dev_get_regmap() instead of the obsolete
      ocelot_init_regmap_from_resource() routine.

---
 drivers/mfd/ocelot-core.c           |   3 +
 drivers/net/dsa/ocelot/Kconfig      |  14 ++
 drivers/net/dsa/ocelot/Makefile     |   5 +
 drivers/net/dsa/ocelot/ocelot_ext.c | 254 ++++++++++++++++++++++++++++
 include/soc/mscc/ocelot.h           |   2 +
 5 files changed, 278 insertions(+)
 create mode 100644 drivers/net/dsa/ocelot/ocelot_ext.c

diff --git a/drivers/mfd/ocelot-core.c b/drivers/mfd/ocelot-core.c
index aa7fa21b354c..b7b9f6855f74 100644
--- a/drivers/mfd/ocelot-core.c
+++ b/drivers/mfd/ocelot-core.c
@@ -188,6 +188,9 @@ static const struct mfd_cell vsc7512_devs[] = {
 		.use_of_reg = true,
 		.num_resources = ARRAY_SIZE(vsc7512_miim1_resources),
 		.resources = vsc7512_miim1_resources,
+	}, {
+		.name = "ocelot-ext-switch",
+		.of_compatible = "mscc,vsc7512-ext-switch",
 	},
 };
 
diff --git a/drivers/net/dsa/ocelot/Kconfig b/drivers/net/dsa/ocelot/Kconfig
index 08db9cf76818..d8b224f8dc97 100644
--- a/drivers/net/dsa/ocelot/Kconfig
+++ b/drivers/net/dsa/ocelot/Kconfig
@@ -1,4 +1,18 @@
 # SPDX-License-Identifier: GPL-2.0-only
+config NET_DSA_MSCC_OCELOT_EXT
+	tristate "Ocelot External Ethernet switch support"
+	depends on NET_DSA && SPI
+	depends on NET_VENDOR_MICROSEMI
+	select MDIO_MSCC_MIIM
+	select MFD_OCELOT_CORE
+	select MSCC_OCELOT_SWITCH_LIB
+	select NET_DSA_TAG_OCELOT_8021Q
+	select NET_DSA_TAG_OCELOT
+	help
+	  This driver supports the VSC7511, VSC7512, VSC7513 and VSC7514 chips
+	  when controlled through SPI. It can be used with the Microsemi dev
+	  boards and an external CPU or custom hardware.
+
 config NET_DSA_MSCC_FELIX
 	tristate "Ocelot / Felix Ethernet switch support"
 	depends on NET_DSA && PCI
diff --git a/drivers/net/dsa/ocelot/Makefile b/drivers/net/dsa/ocelot/Makefile
index f6dd131e7491..d7f3f5a4461c 100644
--- a/drivers/net/dsa/ocelot/Makefile
+++ b/drivers/net/dsa/ocelot/Makefile
@@ -1,11 +1,16 @@
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_NET_DSA_MSCC_FELIX) += mscc_felix.o
+obj-$(CONFIG_NET_DSA_MSCC_OCELOT_EXT) += mscc_ocelot_ext.o
 obj-$(CONFIG_NET_DSA_MSCC_SEVILLE) += mscc_seville.o
 
 mscc_felix-objs := \
 	felix.o \
 	felix_vsc9959.o
 
+mscc_ocelot_ext-objs := \
+	felix.o \
+	ocelot_ext.o
+
 mscc_seville-objs := \
 	felix.o \
 	seville_vsc9953.o
diff --git a/drivers/net/dsa/ocelot/ocelot_ext.c b/drivers/net/dsa/ocelot/ocelot_ext.c
new file mode 100644
index 000000000000..c821cc963787
--- /dev/null
+++ b/drivers/net/dsa/ocelot/ocelot_ext.c
@@ -0,0 +1,254 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/*
+ * Copyright 2021-2022 Innovative Advantage Inc.
+ */
+
+#include <linux/iopoll.h>
+#include <linux/mfd/ocelot.h>
+#include <linux/phylink.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <soc/mscc/ocelot_ana.h>
+#include <soc/mscc/ocelot_dev.h>
+#include <soc/mscc/ocelot_qsys.h>
+#include <soc/mscc/ocelot_vcap.h>
+#include <soc/mscc/ocelot_ptp.h>
+#include <soc/mscc/ocelot_sys.h>
+#include <soc/mscc/ocelot.h>
+#include <soc/mscc/vsc7514_regs.h>
+#include "felix.h"
+
+#define VSC7512_NUM_PORTS		11
+
+#define OCELOT_EXT_MEM_INIT_SLEEP_US	1000
+#define OCELOT_EXT_MEM_INIT_TIMEOUT_US	100000
+
+#define OCELOT_EXT_PORT_MODE_SERDES	(OCELOT_PORT_MODE_SGMII | \
+					 OCELOT_PORT_MODE_QSGMII)
+
+static const u32 vsc7512_port_modes[VSC7512_NUM_PORTS] = {
+	OCELOT_PORT_MODE_INTERNAL,
+	OCELOT_PORT_MODE_INTERNAL,
+	OCELOT_PORT_MODE_INTERNAL,
+	OCELOT_PORT_MODE_INTERNAL,
+	OCELOT_EXT_PORT_MODE_SERDES,
+	OCELOT_EXT_PORT_MODE_SERDES,
+	OCELOT_EXT_PORT_MODE_SERDES,
+	OCELOT_EXT_PORT_MODE_SERDES,
+	OCELOT_EXT_PORT_MODE_SERDES,
+	OCELOT_EXT_PORT_MODE_SERDES,
+	OCELOT_PORT_MODE_SGMII,
+	OCELOT_EXT_PORT_MODE_SERDES,
+};
+
+static const u32 vsc7512_gcb_regmap[] = {
+	REG(GCB_SOFT_RST,			0x0008),
+	REG(GCB_MIIM_MII_STATUS,		0x009c),
+	REG(GCB_PHY_PHY_CFG,			0x00f0),
+	REG(GCB_PHY_PHY_STAT,			0x00f4),
+};
+
+static const u32 *vsc7512_regmap[TARGET_MAX] = {
+	[ANA] = vsc7514_ana_regmap,
+	[QS] = vsc7514_qs_regmap,
+	[QSYS] = vsc7514_qsys_regmap,
+	[REW] = vsc7514_rew_regmap,
+	[SYS] = vsc7514_sys_regmap,
+	[S0] = vsc7514_vcap_regmap,
+	[S1] = vsc7514_vcap_regmap,
+	[S2] = vsc7514_vcap_regmap,
+	[PTP] = vsc7514_ptp_regmap,
+	[GCB] = vsc7512_gcb_regmap,
+	[DEV_GMII] = vsc7514_dev_gmii_regmap,
+};
+
+static void ocelot_ext_reset_phys(struct ocelot *ocelot)
+{
+	ocelot_write(ocelot, 0, GCB_PHY_PHY_CFG);
+	ocelot_write(ocelot, 0x1ff, GCB_PHY_PHY_CFG);
+	mdelay(500);
+}
+
+static int ocelot_ext_mem_init_status(struct ocelot *ocelot)
+{
+	int val, err;
+
+	err = regmap_field_read(ocelot->regfields[SYS_RESET_CFG_MEM_INIT], &val);
+
+	return err ?: val;
+}
+
+static int ocelot_ext_reset(struct ocelot *ocelot)
+{
+	int err, val;
+
+	ocelot_ext_reset_phys(ocelot);
+
+	/* Initialize chip memories */
+	err = regmap_field_write(ocelot->regfields[SYS_RESET_CFG_MEM_ENA], 1);
+	if (err)
+		return err;
+
+	err = regmap_field_write(ocelot->regfields[SYS_RESET_CFG_MEM_INIT], 1);
+	if (err)
+		return err;
+
+	/* MEM_INIT is a self-clearing bit. Wait for it to be clear (should be
+	 * 100us) before enabling the switch core
+	 */
+	err = readx_poll_timeout(ocelot_ext_mem_init_status, ocelot, val, !val,
+				 OCELOT_EXT_MEM_INIT_SLEEP_US,
+				 OCELOT_EXT_MEM_INIT_TIMEOUT_US);
+
+	if (IS_ERR_VALUE(err))
+		return err;
+
+	return regmap_field_write(ocelot->regfields[SYS_RESET_CFG_CORE_ENA], 1);
+}
+
+static void ocelot_ext_phylink_validate(struct ocelot *ocelot, int port,
+					unsigned long *supported,
+					struct phylink_link_state *state)
+{
+	struct felix *felix = ocelot_to_felix(ocelot);
+	struct dsa_switch *ds = felix->ds;
+	struct phylink_config *pl_config;
+	struct dsa_port *dp;
+
+	dp = dsa_to_port(ds, port);
+	pl_config = &dp->pl_config;
+
+	phylink_generic_validate(pl_config, supported, state);
+}
+
+static struct regmap *ocelot_ext_regmap_init(struct ocelot *ocelot,
+					     struct resource *res)
+{
+	return dev_get_regmap(ocelot->dev->parent, res->name);
+}
+
+static const struct ocelot_ops ocelot_ext_ops = {
+	.reset		= ocelot_ext_reset,
+	.wm_enc		= ocelot_wm_enc,
+	.wm_dec		= ocelot_wm_dec,
+	.wm_stat	= ocelot_wm_stat,
+	.port_to_netdev	= felix_port_to_netdev,
+	.netdev_to_port	= felix_netdev_to_port,
+};
+
+static const struct felix_info vsc7512_info = {
+	.target_io_res			= vsc7512_target_io_res,
+	.port_io_res			= vsc7512_port_io_res,
+	.regfields			= vsc7514_regfields,
+	.map				= vsc7512_regmap,
+	.ops				= &ocelot_ext_ops,
+	.stats_layout			= vsc7514_stats_layout,
+	.vcap				= vsc7514_vcap_props,
+	.num_mact_rows			= 1024,
+	.num_ports			= VSC7512_NUM_PORTS,
+	.num_tx_queues			= OCELOT_NUM_TC,
+	.phylink_validate		= ocelot_ext_phylink_validate,
+	.port_modes			= vsc7512_port_modes,
+	.init_regmap			= ocelot_ext_regmap_init,
+};
+
+static int ocelot_ext_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct dsa_switch *ds;
+	struct ocelot *ocelot;
+	struct felix *felix;
+	int err;
+
+	felix = kzalloc(sizeof(*felix), GFP_KERNEL);
+	if (!felix)
+		return -ENOMEM;
+
+	dev_set_drvdata(dev, felix);
+
+	ocelot = &felix->ocelot;
+	ocelot->dev = dev;
+
+	ocelot->num_flooding_pgids = 1;
+
+	felix->info = &vsc7512_info;
+
+	ds = kzalloc(sizeof(*ds), GFP_KERNEL);
+	if (!ds) {
+		err = -ENOMEM;
+		dev_err_probe(dev, err, "Failed to allocate DSA switch\n");
+		goto err_free_felix;
+	}
+
+	ds->dev = dev;
+	ds->num_ports = felix->info->num_ports;
+	ds->num_tx_queues = felix->info->num_tx_queues;
+
+	ds->ops = &felix_switch_ops;
+	ds->priv = ocelot;
+	felix->ds = ds;
+	felix->tag_proto = DSA_TAG_PROTO_OCELOT;
+
+	err = dsa_register_switch(ds);
+	if (err) {
+		dev_err_probe(dev, err, "Failed to register DSA switch\n");
+		goto err_free_ds;
+	}
+
+	return 0;
+
+err_free_ds:
+	kfree(ds);
+err_free_felix:
+	kfree(felix);
+	return err;
+}
+
+static int ocelot_ext_remove(struct platform_device *pdev)
+{
+	struct felix *felix = dev_get_drvdata(&pdev->dev);
+
+	if (!felix)
+		return 0;
+
+	dsa_unregister_switch(felix->ds);
+
+	kfree(felix->ds);
+	kfree(felix);
+
+	dev_set_drvdata(&pdev->dev, NULL);
+
+	return 0;
+}
+
+static void ocelot_ext_shutdown(struct platform_device *pdev)
+{
+	struct felix *felix = dev_get_drvdata(&pdev->dev);
+
+	if (!felix)
+		return;
+
+	dsa_switch_shutdown(felix->ds);
+
+	dev_set_drvdata(&pdev->dev, NULL);
+}
+
+static const struct of_device_id ocelot_ext_switch_of_match[] = {
+	{ .compatible = "mscc,vsc7512-ext-switch" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, ocelot_ext_switch_of_match);
+
+static struct platform_driver ocelot_ext_switch_driver = {
+	.driver = {
+		.name = "ocelot-ext-switch",
+		.of_match_table = of_match_ptr(ocelot_ext_switch_of_match),
+	},
+	.probe = ocelot_ext_probe,
+	.remove = ocelot_ext_remove,
+	.shutdown = ocelot_ext_shutdown,
+};
+module_platform_driver(ocelot_ext_switch_driver);
+
+MODULE_DESCRIPTION("External Ocelot Switch driver");
+MODULE_LICENSE("GPL");
diff --git a/include/soc/mscc/ocelot.h b/include/soc/mscc/ocelot.h
index 17dd61f36563..2ed38110a6cc 100644
--- a/include/soc/mscc/ocelot.h
+++ b/include/soc/mscc/ocelot.h
@@ -460,6 +460,8 @@ enum ocelot_reg {
 	GCB_MIIM_MII_STATUS,
 	GCB_MIIM_MII_CMD,
 	GCB_MIIM_MII_DATA,
+	GCB_PHY_PHY_CFG,
+	GCB_PHY_PHY_STAT,
 	DEV_CLOCK_CFG = DEV_GMII << TARGET_OFFSET,
 	DEV_PORT_MISC,
 	DEV_EVENTS,
-- 
2.25.1