Merge branch 'mlxsw-i2c'

Jiri Pirko says:

====================
mlxsw: Introduce support for I2C bus

Vadim says:

This patchset adds I2C access support for SwitchX, SwitchX2, SwitchIB,
SwitchIB2 and Spectrum silicones.

It contains:
 - Small changes in mlxsw core code, needed for I2C bus support;
 - I2C driver, which obtains I2C input/output mailboxes setting and
   provides command interface implementation.
 - Minimal driver, which works on top of I2C driver and allows running
   of mlxsw command interface over I2C bus;

Use case:
On system, which does not have PCI to ASIC (BMC), hwmon functionality
(sensors, pwm, tacho) will be available through I2C.

Usage (manual probing):
echo mlxsw_minimal 0x48 > /sys/bus/i2c/devices/i2c-2/new_device

Sysfs interface:
/sys/bus/i2c/devices/2-0048/hwmon/hwmon5/pwm1
/sys/bus/i2c/devices/2-0048/hwmon/hwmon5/temp1_input
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/Kconfig

@@ -29,6 +29,16 @@ config MLXSW_PCI
 	  To compile this driver as a module, choose M here: the
 	  module will be called mlxsw_pci.
 
+config MLXSW_I2C
+	tristate "I2C bus implementation for Mellanox Technologies Switch ASICs"
+	depends on I2C && MLXSW_CORE
+	default m
+	---help---
+	  This is I2C bus implementation for Mellanox Technologies Switch ASICs.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called mlxsw_i2c.
+
 config MLXSW_SWITCHIB
 	tristate "Mellanox Technologies SwitchIB and SwitchIB-2 support"
 	depends on MLXSW_CORE && NET_SWITCHDEV
@@ -69,3 +79,14 @@ config MLXSW_SPECTRUM_DCB
 	---help---
 	  Say Y here if you want to use Data Center Bridging (DCB) in the
 	  driver.
+
+config MLXSW_MINIMAL
+	tristate "Mellanox Technologies minimal I2C support"
+	depends on MLXSW_CORE && MLXSW_I2C
+	default m
+	---help---
+	  This driver supports I2C access for Mellanox Technologies Switch
+	  ASICs.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called mlxsw_minimal.

drivers/net/ethernet/mellanox/mlxsw/Makefile

@@ -3,6 +3,8 @@ mlxsw_core-objs			:= core.o
 mlxsw_core-$(CONFIG_MLXSW_CORE_HWMON) += core_hwmon.o
 obj-$(CONFIG_MLXSW_PCI)		+= mlxsw_pci.o
 mlxsw_pci-objs			:= pci.o
+obj-$(CONFIG_MLXSW_I2C)		+= mlxsw_i2c.o
+mlxsw_i2c-objs			:= i2c.o
 obj-$(CONFIG_MLXSW_SWITCHIB)	+= mlxsw_switchib.o
 mlxsw_switchib-objs		:= switchib.o
 obj-$(CONFIG_MLXSW_SWITCHX2)	+= mlxsw_switchx2.o
@@ -12,3 +14,5 @@ mlxsw_spectrum-objs		:= spectrum.o spectrum_buffers.o \
 				   spectrum_switchdev.o spectrum_router.o \
 				   spectrum_kvdl.o
 mlxsw_spectrum-$(CONFIG_MLXSW_SPECTRUM_DCB)	+= spectrum_dcb.o
+obj-$(CONFIG_MLXSW_MINIMAL)	+= mlxsw_minimal.o
+mlxsw_minimal-objs		:= minimal.o

drivers/net/ethernet/mellanox/mlxsw/core.c

@@ -598,6 +598,9 @@ static int mlxsw_emad_init(struct mlxsw_core *mlxsw_core)
 	u64 tid;
 	int err;
 
+	if (!(mlxsw_core->bus->features & MLXSW_BUS_F_TXRX))
+		return 0;
+
 	/* Set the upper 32 bits of the transaction ID field to a random
 	 * number. This allows us to discard EMADs addressed to other
 	 * devices.
@@ -634,6 +637,9 @@ static void mlxsw_emad_fini(struct mlxsw_core *mlxsw_core)
 {
 	char hpkt_pl[MLXSW_REG_HPKT_LEN];
 
+	if (!(mlxsw_core->bus->features & MLXSW_BUS_F_TXRX))
+		return;
+
 	mlxsw_core->emad.use_emad = false;
 	mlxsw_reg_hpkt_pack(hpkt_pl, MLXSW_REG_HPKT_ACTION_DISCARD,
 			    MLXSW_TRAP_ID_ETHEMAD);
@@ -1156,9 +1162,11 @@ int mlxsw_core_bus_device_register(const struct mlxsw_bus_info *mlxsw_bus_info,
 	if (err)
 		goto err_hwmon_init;
 
+	if (mlxsw_driver->init) {
 		err = mlxsw_driver->init(mlxsw_core, mlxsw_bus_info);
 		if (err)
 			goto err_driver_init;
+	}
 
 	err = mlxsw_core_debugfs_init(mlxsw_core);
 	if (err)
@@ -1167,6 +1175,7 @@ int mlxsw_core_bus_device_register(const struct mlxsw_bus_info *mlxsw_bus_info,
 	return 0;
 
 err_debugfs_init:
+	if (mlxsw_core->driver->fini)
 		mlxsw_core->driver->fini(mlxsw_core);
 err_driver_init:
 err_hwmon_init:
@@ -1193,6 +1202,7 @@ void mlxsw_core_bus_device_unregister(struct mlxsw_core *mlxsw_core)
 	struct devlink *devlink = priv_to_devlink(mlxsw_core);
 
 	mlxsw_core_debugfs_fini(mlxsw_core);
+	if (mlxsw_core->driver->fini)
 		mlxsw_core->driver->fini(mlxsw_core);
 	devlink_unregister(devlink);
 	mlxsw_emad_fini(mlxsw_core);

drivers/net/ethernet/mellanox/mlxsw/core.h

@@ -268,6 +268,8 @@ u64 mlxsw_core_res_get(struct mlxsw_core *mlxsw_core,
 #define MLXSW_CORE_RES_GET(res, short_res_id)			\
 	mlxsw_core_res_get(res, MLXSW_RES_ID_##short_res_id)
 
+#define MLXSW_BUS_F_TXRX	BIT(0)
+
 struct mlxsw_bus {
 	const char *kind;
 	int (*init)(void *bus_priv, struct mlxsw_core *mlxsw_core,
@@ -283,6 +285,7 @@ struct mlxsw_bus {
 			char *in_mbox, size_t in_mbox_size,
 			char *out_mbox, size_t out_mbox_size,
 			u8 *p_status);
+	u8 features;
 };
 
 struct mlxsw_bus_info {

drivers/net/ethernet/mellanox/mlxsw/i2c.h

+/*
+ * drivers/net/ethernet/mellanox/mlxsw/i2c.h
+ * Copyright (c) 2016 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2016 Vadim Pasternak <vadimp@mellanox.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _MLXSW_I2C_H
+#define _MLXSW_I2C_H
+
+#include <linux/i2c.h>
+
+#if IS_ENABLED(CONFIG_MLXSW_I2C)
+
+int mlxsw_i2c_driver_register(struct i2c_driver *i2c_driver);
+void mlxsw_i2c_driver_unregister(struct i2c_driver *i2c_driver);
+
+#else
+
+static inline int
+mlxsw_i2c_driver_register(struct i2c_driver *i2c_driver)
+{
+	return -ENODEV;
+}
+
+static inline void
+mlxsw_i2c_driver_unregister(struct i2c_driver *i2c_driver)
+{
+}
+
+#endif
+
+#endif

drivers/net/ethernet/mellanox/mlxsw/minimal.c

+/*
+ * drivers/net/ethernet/mellanox/mlxsw/minimal.c
+ * Copyright (c) 2016 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2016 Vadim Pasternak <vadimp@mellanox.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/types.h>
+
+#include "core.h"
+#include "i2c.h"
+
+static const char mlxsw_minimal_driver_name[] = "mlxsw_minimal";
+
+static const struct mlxsw_config_profile mlxsw_minimal_config_profile;
+
+static struct mlxsw_driver mlxsw_minimal_driver = {
+	.kind		= mlxsw_minimal_driver_name,
+	.priv_size	= 1,
+	.profile	= &mlxsw_minimal_config_profile,
+};
+
+static const struct i2c_device_id mlxsw_minimal_i2c_id[] = {
+	{ "mlxsw_minimal", 0},
+	{ },
+};
+
+static struct i2c_driver mlxsw_minimal_i2c_driver = {
+	.driver.name = "mlxsw_minimal",
+	.class = I2C_CLASS_HWMON,
+	.id_table = mlxsw_minimal_i2c_id,
+};
+
+static int __init mlxsw_minimal_module_init(void)
+{
+	int err;
+
+	err = mlxsw_core_driver_register(&mlxsw_minimal_driver);
+	if (err)
+		return err;
+
+	err = mlxsw_i2c_driver_register(&mlxsw_minimal_i2c_driver);
+	if (err)
+		goto err_i2c_driver_register;
+
+	return 0;
+
+err_i2c_driver_register:
+	mlxsw_core_driver_unregister(&mlxsw_minimal_driver);
+
+	return err;
+}
+
+static void __exit mlxsw_minimal_module_exit(void)
+{
+	mlxsw_i2c_driver_unregister(&mlxsw_minimal_i2c_driver);
+	mlxsw_core_driver_unregister(&mlxsw_minimal_driver);
+}
+
+module_init(mlxsw_minimal_module_init);
+module_exit(mlxsw_minimal_module_exit);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
+MODULE_DESCRIPTION("Mellanox minimal driver");
+MODULE_DEVICE_TABLE(i2c, mlxsw_minimal_i2c_id);

drivers/net/ethernet/mellanox/mlxsw/pci.c

@@ -1755,6 +1755,7 @@ static const struct mlxsw_bus mlxsw_pci_bus = {
 	.skb_transmit_busy	= mlxsw_pci_skb_transmit_busy,
 	.skb_transmit		= mlxsw_pci_skb_transmit,
 	.cmd_exec		= mlxsw_pci_cmd_exec,
+	.features		= MLXSW_BUS_F_TXRX,
 };
 
 static int mlxsw_pci_sw_reset(struct mlxsw_pci *mlxsw_pci,