RE: [PATCH v4] i2c: Adding support for Intel iSMT SMBus 2.0 host controller

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




> -----Original Message-----
> From: linux-i2c-owner@xxxxxxxxxxxxxxx [mailto:linux-i2c-
> owner@xxxxxxxxxxxxxxx] On Behalf Of Bill E Brown
> Sent: Thursday, December 06, 2012 5:37 PM
> To: Wolfram Sang
> Cc: Jean Delvare; Heasley, Seth; linux-i2c@xxxxxxxxxxxxxxx; Brown, Bill E
> Subject: [PATCH v4] i2c: Adding support for Intel iSMT SMBus 2.0 host
> controller
> 
> From: Bill Brown <bill.e.brown@xxxxxxxxx>
> 
> The iSMT (Intel SMBus Message Transport) supports multi-master
> I2C/SMBus, as well as IPMI.  It's operation is DMA-based and utilizes
> descriptors to initiate transactions on the bus.
> 
> The iSMT hardware can act as both a master and a target, although this driver
> only supports being a master.
> 

Forgot to run checkpatch on v3, please use v4.

Bill

> Signed-off-by: Bill Brown <bill.e.brown@xxxxxxxxx>
> ---
>  Documentation/i2c/busses/i2c-ismt |   36 ++
>  drivers/i2c/busses/Kconfig        |   10 +
>  drivers/i2c/busses/Makefile       |    1 +
>  drivers/i2c/busses/i2c-ismt.c     |  911
> +++++++++++++++++++++++++++++++++++++
>  4 files changed, 958 insertions(+), 0 deletions(-)  create mode 100644
> Documentation/i2c/busses/i2c-ismt  create mode 100644
> drivers/i2c/busses/i2c-ismt.c
> 
> diff --git a/Documentation/i2c/busses/i2c-ismt
> b/Documentation/i2c/busses/i2c-ismt
> new file mode 100644
> index 0000000..ed6375c
> --- /dev/null
> +++ b/Documentation/i2c/busses/i2c-ismt
> @@ -0,0 +1,36 @@
> +Kernel driver i2c-ismt
> +
> +Supported adapters:
> +  * Intel S12xx series SOCs
> +
> +Authors:
> +	Bill Brown <bill.e.brown@xxxxxxxxx>
> +
> +
> +Module Parameters
> +-----------------
> +
> +* bus_speed (unsigned int)
> +Allows changing of the bus speed.  Normally, the bus speed is set by
> +the BIOS and never needs to be changed.  However, some SMBus analyzers
> +are too slow for monitoring the bus during debug, thus the need for this
> module parameter.
> +Available bus frequency settings:
> +  0  no change
> +  1  80 kHz
> +  2  100 kHz
> +  3  400 kHz
> +  4  1 MHz
> +
> +
> +Description
> +-----------
> +
> +The S12xx series of SOCs have a pair of integrated SMBus 2.0
> +controllers targeted primarily at the microserver and storage markets.
> +
> +The S12xx series contain a pair of PCI functions.  An output of lspci
> +will show something similar to the following:
> +
> +  00:13.0 System peripheral: Intel Corporation Device 0xc59
> +  00:13.1 System peripheral: Intel Corporation Device 0xc5a
> +
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index
> 7244c8b..64d5756 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -119,6 +119,16 @@ config I2C_ISCH
>  	  This driver can also be built as a module. If so, the module
>  	  will be called i2c-isch.
> 
> +config I2C_ISMT
> +	tristate "Intel iSMT SMBus Controller"
> +	depends on PCI
> +	help
> +	  If you say yes to this option, support will be included for the Intel
> +	  iSMT SMBus host controller interface.
> +
> +	  This driver can also be built as a module.  If so, the module will be
> +	  called i2c-ismt.
> +
>  config I2C_PIIX4
>  	tristate "Intel PIIX4 and compatible
> (ATI/AMD/Serverworks/Broadcom/SMSC)"
>  	depends on PCI
> diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index
> ce3c2be..527a1f1 100644
> --- a/drivers/i2c/busses/Makefile
> +++ b/drivers/i2c/busses/Makefile
> @@ -14,6 +14,7 @@ obj-$(CONFIG_I2C_AMD756_S4882)	+= i2c-
> amd756-s4882.o
>  obj-$(CONFIG_I2C_AMD8111)	+= i2c-amd8111.o
>  obj-$(CONFIG_I2C_I801)		+= i2c-i801.o
>  obj-$(CONFIG_I2C_ISCH)		+= i2c-isch.o
> +obj-$(CONFIG_I2C_ISMT)		+= i2c-ismt.o
>  obj-$(CONFIG_I2C_NFORCE2)	+= i2c-nforce2.o
>  obj-$(CONFIG_I2C_NFORCE2_S4985)	+= i2c-nforce2-s4985.o
>  obj-$(CONFIG_I2C_PIIX4)		+= i2c-piix4.o
> diff --git a/drivers/i2c/busses/i2c-ismt.c b/drivers/i2c/busses/i2c-ismt.c new
> file mode 100644 index 0000000..17b1bdd
> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-ismt.c
> @@ -0,0 +1,911 @@
> +/*
> + * This file is provided under a dual BSD/GPLv2 license.  When using or
> + * redistributing this file, you may do so under either license.
> + *
> + * Copyright(c) 2012 Intel Corporation. All rights reserved.
> + *
> + * GPL LICENSE SUMMARY
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of version 2 of the GNU General Public License as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> GNU
> + * General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
> + * The full GNU General Public License is included in this distribution
> + * in the file called LICENSE.GPL.
> + *
> + * BSD LICENSE
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + *
> + *   * Redistributions of source code must retain the above copyright
> + *     notice, this list of conditions and the following disclaimer.
> + *   * 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.
> + *   * Neither the name of Intel Corporation nor the names of its
> + *     contributors may be used to endorse or promote products derived
> + *     from this software without specific prior written permission.
> + *
> + * 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.
> + */
> +
> +/*
> + *  Supports the SMBus Message Transport (SMT) in the Intel Atom
> +Processor
> + *  S12xx Product Family.
> + *
> + *  Features supported by this driver:
> + *  Hardware PEC                     yes
> + *  Block buffer                     yes
> + *  Block process call transaction   no
> + *  Slave mode                       no
> + */
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/pci.h>
> +#include <linux/kernel.h>
> +#include <linux/stddef.h>
> +#include <linux/completion.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/i2c.h>
> +#include <linux/acpi.h>
> +#include <linux/interrupt.h>
> +
> +/* PCI Address Constants */
> +#define SMBBAR		0
> +
> +/* PCI DIDs for the Intel SMBus Message Transport (SMT) Devices */
> +#define PCI_DEVICE_ID_INTEL_S1200_SMB_SMT0	0x0c59
> +#define PCI_DEVICE_ID_INTEL_S1200_SMB_SMT1	0x0c5a
> +
> +#define ISMT_DESC_ENTRIES	32	/* number of descriptor entries */
> +#define ISMT_MAX_RETRIES	3	/* number of SMBus retries to
> attempt */
> +
> +/* Hardware Descriptor Constants - Control Field */
> +#define ISMT_DESC_CWRL	0x01	/* Command/Write Length */
> +#define ISMT_DESC_BLK	0X04	/* Perform Block Transaction */
> +#define ISMT_DESC_FAIR	0x08	/* Set fairness flag upon successful
> arbit. */
> +#define ISMT_DESC_PEC	0x10	/* Packet Error Code */
> +#define ISMT_DESC_I2C	0x20	/* I2C Enable */
> +#define ISMT_DESC_INT	0x40	/* Interrupt */
> +#define ISMT_DESC_SOE	0x80	/* Stop On Error */
> +
> +/* Hardware Descriptor Constants - Status Field */
> +#define ISMT_DESC_SCS	0x01	/* Success */
> +#define ISMT_DESC_DLTO	0x04	/* Data Low Time Out */
> +#define ISMT_DESC_NAK	0x08	/* NAK Received */
> +#define ISMT_DESC_CRC	0x10	/* CRC Error */
> +#define ISMT_DESC_CLTO	0x20	/* Clock Low Time Out */
> +#define ISMT_DESC_COL	0x40	/* Collisions */
> +#define ISMT_DESC_LPR	0x80	/* Large Packet Received */
> +
> +/* Macros */
> +#define ISMT_DESC_ADDR_RW(addr, rw) (((addr) << 1) | (rw))
> +
> +/* iSMT General Register address offsets (SMBBAR + <addr>) */
> +#define ISMT_GR_GCTRL		0x000	/* General Control */
> +#define ISMT_GR_SMTICL		0x008	/* SMT Interrupt Cause
> Location */
> +#define ISMT_GR_ERRINTMSK	0x010	/* Error Interrupt Mask */
> +#define ISMT_GR_ERRAERMSK	0x014	/* Error AER Mask */
> +#define ISMT_GR_ERRSTS		0x018	/* Error Status */
> +#define ISMT_GR_ERRINFO		0x01c	/* Error Information */
> +
> +/* iSMT Master Registers */
> +#define ISMT_MSTR_MDBA		0x100	/* Master Descriptor Base
> Address */
> +#define ISMT_MSTR_MCTRL		0x108	/* Master Control */
> +#define ISMT_MSTR_MSTS		0x10c	/* Master Status */
> +#define ISMT_MSTR_MDS		0x110	/* Master Descriptor Size */
> +#define ISMT_MSTR_RPOLICY	0x114	/* Retry Policy */
> +
> +/* iSMT Miscellaneous Registers */
> +#define ISMT_SPGT	0x300	/* SMBus PHY Global Timing */
> +
> +/* General Control Register (GCTRL) bit definitions */
> +#define ISMT_GCTRL_TRST	0x04	/* Target Reset */
> +#define ISMT_GCTRL_KILL	0x08	/* Kill */
> +#define ISMT_GCTRL_SRST	0x40	/* Soft Reset */
> +
> +/* Master Control Register (MCTRL) bit definitions */
> +#define ISMT_MCTRL_SS	0x01		/* Start/Stop */
> +#define ISMT_MCTRL_MEIE	0x10		/* Master Error Interrupt
> Enable */
> +#define ISMT_MCTRL_FMHP	0x00ff0000	/* Firmware Master Head Ptr
> (FMHP) */
> +
> +/* Master Status Register (MSTS) bit definitions */
> +#define ISMT_MSTS_HMTP	0xff0000	/* HW Master Tail Pointer
> (HMTP) */
> +#define ISMT_MSTS_MIS	0x20		/* Master Interrupt Status
> (MIS) */
> +#define ISMT_MSTS_MEIS	0x10		/* Master Error Int Status
> (MEIS) */
> +#define ISMT_MSTS_IP	0x01		/* In Progress */
> +
> +/* Master Descriptor Size (MDS) bit definitions */
> +#define ISMT_MDS_MASK	0xff	/* Master Descriptor Size mask
> (MDS) */
> +
> +/* SMBus PHY Global Timing Register (SPGT) bit definitions */
> +#define ISMT_SPGT_SPD_MASK	0xc0000000	/* SMBus Speed
> mask */
> +#define ISMT_SPGT_SPD_80K	0x00		/* 80 kHz */
> +#define ISMT_SPGT_SPD_100K	(0x1 << 30)	/* 100 kHz */
> +#define ISMT_SPGT_SPD_400K	(0x2 << 30)	/* 400 kHz */
> +#define ISMT_SPGT_SPD_1M	(0x3 << 30)	/* 1 MHz */
> +
> +
> +/* MSI Control Register (MSICTL) bit definitions */
> +#define ISMT_MSICTL_MSIE	0x01	/* MSI Enable */
> +
> +/* iSMT Hardware Descriptor */
> +struct ismt_desc {
> +	u8 tgtaddr_rw;	/* target address & r/w bit */
> +	u8 wr_len_cmd;	/* write length in bytes or a command */
> +	u8 rd_len;	/* read length */
> +	u8 control;	/* control bits */
> +	u8 status;	/* status bits */
> +	u8 retry;	/* collision retry and retry count */
> +	u8 rxbytes;	/* received bytes */
> +	u8 txbytes;	/* transmitted bytes */
> +	u32 dptr_low;	/* lower 32 bit of the data pointer */
> +	u32 dptr_high;	/* upper 32 bit of the data pointer */
> +} __packed;
> +
> +struct ismt_priv {
> +	struct i2c_adapter adapter;
> +	void *smba;				/* PCI BAR */
> +	struct pci_dev *pci_dev;
> +	struct ismt_desc *hw;			/* descriptor virt base addr */
> +	dma_addr_t io_rng_dma;			/* descriptor HW
> base addr */
> +	u8 head;				/* ring buffer head pointer */
> +	struct completion cmp;			/* interrupt completion */
> +	u8 dma_buffer[I2C_SMBUS_BLOCK_MAX + 3];	/* temp R/W data
> buffer */
> +	bool using_msi;				/* type of interrupt
> flag */
> +};
> +
> +/**
> + * ismt_ids - PCI device IDs supported by this driver  */ static const
> +DEFINE_PCI_DEVICE_TABLE(ismt_ids) = {
> +	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL,
> PCI_DEVICE_ID_INTEL_S1200_SMB_SMT0) },
> +	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL,
> PCI_DEVICE_ID_INTEL_S1200_SMB_SMT1) },
> +	{ 0, }
> +};
> +
> +MODULE_DEVICE_TABLE(pci, ismt_ids);
> +
> +/* Bus speed control bits for slow debuggers - refer to the docs for
> +usage */ static unsigned int bus_speed; module_param(bus_speed, uint,
> +S_IRUGO); MODULE_PARM_DESC(bus_speed, "Bus Speed");
> +
> +#if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
> +/**
> + * ismt_desc_dump() - dump the contents of a descriptor for debug
> +purposes
> + * @priv: iSMT private data
> + */
> +static void ismt_desc_dump(struct ismt_priv *priv) {
> +	struct device *dev = &priv->pci_dev->dev;
> +	struct ismt_desc *desc = &priv->hw[priv->head];
> +
> +	dev_dbg(dev, "Dump of the descriptor struct:  0x%X\n", priv->head);
> +	dev_dbg(dev, "\ttgtaddr_rw=0x%02X\n", desc->tgtaddr_rw);
> +	dev_dbg(dev, "\twr_len_cmd=0x%02X\n", desc->wr_len_cmd);
> +	dev_dbg(dev, "\trd_len=    0x%02X\n", desc->rd_len);
> +	dev_dbg(dev, "\tcontrol=   0x%02X\n", desc->control);
> +	dev_dbg(dev, "\tstatus=    0x%02X\n", desc->status);
> +	dev_dbg(dev, "\tretry=     0x%02X\n", desc->retry);
> +	dev_dbg(dev, "\trxbytes=   0x%02X\n", desc->rxbytes);
> +	dev_dbg(dev, "\ttxbytes=   0x%02X\n", desc->txbytes);
> +	dev_dbg(dev, "\tdptr_low=  0x%08X\n", desc->dptr_low);
> +	dev_dbg(dev, "\tdptr_high= 0x%08X\n", desc->dptr_high); }
> +
> +/**
> + * ismt_gen_reg_dump() - dump the iSMT General Registers
> + * @priv: iSMT private data
> + */
> +static void ismt_gen_reg_dump(struct ismt_priv *priv) {
> +	struct device *dev = &priv->pci_dev->dev;
> +
> +	dev_dbg(dev, "Dump of the iSMT General Registers\n");
> +	dev_dbg(dev, "  GCTRL.... : (0x%p)=0x%X\n",
> +		priv->smba + ISMT_GR_GCTRL,
> +		readl(priv->smba + ISMT_GR_GCTRL));
> +	dev_dbg(dev, "  SMTICL... : (0x%p)=0x%016lX\n",
> +		priv->smba + ISMT_GR_SMTICL,
> +		readq(priv->smba + ISMT_GR_SMTICL));
> +	dev_dbg(dev, "  ERRINTMSK : (0x%p)=0x%X\n",
> +		priv->smba + ISMT_GR_ERRINTMSK,
> +		readl(priv->smba + ISMT_GR_ERRINTMSK));
> +	dev_dbg(dev, "  ERRAERMSK : (0x%p)=0x%X\n",
> +		priv->smba + ISMT_GR_ERRAERMSK,
> +		readl(priv->smba + ISMT_GR_ERRAERMSK));
> +	dev_dbg(dev, "  ERRSTS... : (0x%p)=0x%X\n",
> +		priv->smba + ISMT_GR_ERRSTS,
> +		readl(priv->smba + ISMT_GR_ERRSTS));
> +	dev_dbg(dev, "  ERRINFO.. : (0x%p)=0x%X\n",
> +		priv->smba + ISMT_GR_ERRINFO,
> +		readl(priv->smba + ISMT_GR_ERRINFO)); }
> +
> +/**
> + * ismt_mstr_reg_dump() - dump the iSMT Master Registers
> + * @priv: iSMT private data
> + */
> +static void ismt_mstr_reg_dump(struct ismt_priv *priv) {
> +	struct device *dev = &priv->pci_dev->dev;
> +
> +	dev_dbg(dev, "Dump of the iSMT Master Registers\n");
> +	dev_dbg(dev, "  MDBA..... : (0x%p)=0x%016lX\n",
> +		priv->smba + ISMT_MSTR_MDBA,
> +		readq(priv->smba + ISMT_MSTR_MDBA));
> +	dev_dbg(dev, "  MCTRL.... : (0x%p)=0x%X\n",
> +		priv->smba + ISMT_MSTR_MCTRL,
> +		readl(priv->smba + ISMT_MSTR_MCTRL));
> +	dev_dbg(dev, "  MSTS..... : (0x%p)=0x%X\n",
> +		priv->smba + ISMT_MSTR_MSTS,
> +		readl(priv->smba + ISMT_MSTR_MSTS));
> +	dev_dbg(dev, "  MDS...... : (0x%p)=0x%X\n",
> +		priv->smba + ISMT_MSTR_MDS,
> +		readl(priv->smba + ISMT_MSTR_MDS));
> +	dev_dbg(dev, "  RPOLICY.. : (0x%p)=0x%X\n",
> +		priv->smba + ISMT_MSTR_RPOLICY,
> +		readl(priv->smba + ISMT_MSTR_RPOLICY));
> +	dev_dbg(dev, "  SPGT..... : (0x%p)=0x%X\n",
> +		priv->smba + ISMT_SPGT,
> +		readl(priv->smba + ISMT_SPGT));
> +}
> +#endif
> +
> +/**
> + * ismt_submit_desc() - add a descriptor to the ring
> + * @priv: iSMT private data
> + */
> +static void ismt_submit_desc(struct ismt_priv *priv) {
> +	uint fmhp;
> +	uint val;
> +
> +	ismt_desc_dump(priv);
> +	ismt_gen_reg_dump(priv);
> +	ismt_mstr_reg_dump(priv);
> +
> +	/* Set the FMHP (Firmware Master Head Pointer)*/
> +	fmhp = ((priv->head + 1) % ISMT_DESC_ENTRIES) << 16;
> +	val = readl(priv->smba + ISMT_MSTR_MCTRL);
> +	writel((val & ~ISMT_MCTRL_FMHP) | fmhp,
> +	       priv->smba + ISMT_MSTR_MCTRL);
> +
> +	/* Set the start bit */
> +	val = readl(priv->smba + ISMT_MSTR_MCTRL);
> +	writel(val | ISMT_MCTRL_SS,
> +	       priv->smba + ISMT_MSTR_MCTRL);
> +}
> +
> +/**
> + * ismt_process_desc() - handle the completion of the descriptor
> + * @desc: the iSMT hardware descriptor
> + * @data: data buffer from the upper layer
> + * @dma_buffer: temporary buffer for the DMA engine
> + * @size: SMBus transaction type
> + */
> +static int ismt_process_desc(const struct ismt_desc *desc,
> +			     union i2c_smbus_data *data,
> +			     u8 *dma_buffer, int size)
> +{
> +	if (likely(desc->status & ISMT_DESC_SCS)) {
> +		if (size != I2C_SMBUS_QUICK)
> +			memcpy(data, dma_buffer, sizeof(*data));
> +		return 0;
> +	}
> +
> +	if (likely(desc->status & ISMT_DESC_NAK))
> +		return -ENXIO;
> +
> +	if (desc->status & ISMT_DESC_CRC)
> +		return -EBADMSG;
> +
> +	if (desc->status & ISMT_DESC_COL)
> +		return -EAGAIN;
> +
> +	if (desc->status & ISMT_DESC_LPR)
> +		return -EPROTO;
> +
> +	if (desc->status & (ISMT_DESC_DLTO | ISMT_DESC_CLTO))
> +		return -ETIMEDOUT;
> +
> +	return -EIO;
> +}
> +
> +/**
> + * ismt_access() - process an SMBus command
> + * @adap: the i2c host adapter
> + * @addr: address of the i2c/SMBus target
> + * @flags: command options
> + * @read_write: read from or write to device
> + * @command: the i2c/SMBus command to issue
> + * @size: SMBus transaction type
> + * @data: read/write data buffer
> + */
> +static int ismt_access(struct i2c_adapter *adap, u16 addr,
> +		       unsigned short flags, char read_write, u8 command,
> +		       int size, union i2c_smbus_data *data) {
> +	int ret;
> +	dma_addr_t dma_addr = 0; /* address of the data buffer */
> +	u8 dma_size = 0;
> +	enum dma_data_direction dma_direction = 0;
> +	struct ismt_desc *desc;
> +	struct ismt_priv *priv = i2c_get_adapdata(adap);
> +	struct device *dev = &priv->pci_dev->dev;
> +
> +	desc = &priv->hw[priv->head];
> +
> +	/* Initialize the descriptor */
> +	memset(desc, 0, sizeof(struct ismt_desc));
> +	desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(addr, read_write);
> +
> +	/* Create a temporary buffer for the DMA transaction */
> +	/* and insert the command at the beginning of the buffer */
> +	if (size != I2C_SMBUS_QUICK) {
> +		memcpy(priv->dma_buffer + 1, data, sizeof(*data));
> +		priv->dma_buffer[0] = command;
> +	}
> +
> +	/* Initialize common control bits */
> +	if (likely(priv->using_msi))
> +		desc->control = ISMT_DESC_INT | ISMT_DESC_FAIR;
> +	else
> +		desc->control = ISMT_DESC_FAIR;
> +
> +	if ((flags & I2C_CLIENT_PEC) && (size != I2C_SMBUS_QUICK)
> +	    && (size != I2C_SMBUS_I2C_BLOCK_DATA))
> +		desc->control |= ISMT_DESC_PEC;
> +
> +	switch (size) {
> +	case I2C_SMBUS_QUICK:
> +		dev_dbg(dev, "I2C_SMBUS_QUICK\n");
> +		break;
> +
> +	case I2C_SMBUS_BYTE:
> +		if (read_write == I2C_SMBUS_WRITE) {
> +			/*
> +			 * Send Byte
> +			 * The command field contains the write data
> +			 */
> +			dev_dbg(dev, "I2C_SMBUS_BYTE:  WRITE\n");
> +			desc->control |= ISMT_DESC_CWRL;
> +			desc->wr_len_cmd = command;
> +		} else {
> +			/* Receive Byte */
> +			dev_dbg(dev, "I2C_SMBUS_BYTE:  READ\n");
> +			dma_size = 1;
> +			dma_direction = DMA_FROM_DEVICE;
> +			desc->rd_len = 1;
> +		}
> +
> +		break;
> +
> +	case I2C_SMBUS_BYTE_DATA:
> +		if (read_write == I2C_SMBUS_WRITE) {
> +			/*
> +			 * Write Byte
> +			 * Command plus 1 data byte
> +			 */
> +			dev_dbg(dev, "I2C_SMBUS_BYTE_DATA:  WRITE\n");
> +			desc->wr_len_cmd = 2;
> +			dma_size = 2;
> +			dma_direction = DMA_TO_DEVICE;
> +		} else {
> +			/* Read Byte */
> +			dev_dbg(dev, "I2C_SMBUS_BYTE_DATA:  READ\n");
> +			desc->control |= ISMT_DESC_CWRL;
> +			desc->wr_len_cmd = command;
> +			desc->rd_len = 1;
> +			dma_size = 1;
> +			dma_direction = DMA_FROM_DEVICE;
> +		}
> +
> +		break;
> +
> +	case I2C_SMBUS_WORD_DATA:
> +		if (read_write == I2C_SMBUS_WRITE) {
> +			/* Write Word */
> +			dev_dbg(dev, "I2C_SMBUS_WORD_DATA:
> WRITE\n");
> +			desc->wr_len_cmd = 3;
> +			dma_size = 3;
> +			dma_direction = DMA_TO_DEVICE;
> +		} else {
> +			/* Read Word */
> +			dev_dbg(dev, "I2C_SMBUS_WORD_DATA:
> READ\n");
> +			desc->wr_len_cmd = command;
> +			desc->control |= ISMT_DESC_CWRL;
> +			desc->rd_len = 2;
> +			dma_size = 2;
> +			dma_direction = DMA_FROM_DEVICE;
> +		}
> +
> +		break;
> +
> +	case I2C_SMBUS_PROC_CALL:
> +		dev_dbg(dev, "I2C_SMBUS_PROC_CALL\n");
> +		desc->wr_len_cmd = 3;
> +		desc->rd_len = 2;
> +		dma_size = 3;
> +		dma_direction = DMA_BIDIRECTIONAL;
> +		break;
> +
> +	case I2C_SMBUS_BLOCK_DATA:
> +		if (read_write == I2C_SMBUS_WRITE) {
> +			/* Block Write */
> +			dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA:
> WRITE\n");
> +			dma_size = data->block[0] + 1;
> +			dma_direction = DMA_TO_DEVICE;
> +			desc->wr_len_cmd = dma_size;
> +			desc->control |= ISMT_DESC_BLK;
> +		} else {
> +			/* Block Read */
> +			dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA:
> READ\n");
> +			dma_size = I2C_SMBUS_BLOCK_MAX;
> +			dma_direction = DMA_FROM_DEVICE;
> +			desc->rd_len = dma_size;
> +			desc->wr_len_cmd = command;
> +			desc->control |= (ISMT_DESC_BLK |
> ISMT_DESC_CWRL);
> +		}
> +
> +		break;
> +
> +	default:
> +		dev_err(dev, "Unsupported transaction %d\n",
> +			size);
> +		return -EOPNOTSUPP;
> +	}
> +
> +	/* map the data buffer */
> +	if (dma_size != 0) {
> +		dev_dbg(dev, " dev=%p\n", dev);
> +		dev_dbg(dev, " data=%p\n", data);
> +		dev_dbg(dev, " dma_buffer=%p\n", priv->dma_buffer);
> +		dev_dbg(dev, " dma_size=%d\n", dma_size);
> +		dev_dbg(dev, " dma_direction=%d\n", dma_direction);
> +
> +		dma_addr = dma_map_single(&priv->pci_dev->dev,
> +				      priv->dma_buffer,
> +				      dma_size,
> +				      dma_direction);
> +
> +		dev_dbg(dev, " dma_addr = 0x%016llX\n",
> +			dma_addr);
> +
> +		desc->dptr_low = lower_32_bits(dma_addr);
> +		desc->dptr_high = upper_32_bits(dma_addr);
> +	}
> +
> +	INIT_COMPLETION(priv->cmp);
> +
> +	/* Add the descriptor */
> +	ismt_submit_desc(priv);
> +
> +	/* Now we wait for interrupt completion, 1s */
> +	ret = wait_for_completion_interruptible_timeout(&priv->cmp,
> HZ*1);
> +
> +	/* unmap the data buffer */
> +	if (dma_size != 0)
> +		dma_unmap_single(&adap->dev, dma_addr, dma_size,
> dma_direction);
> +
> +	if (likely(ret > 0))
> +		/* do any post processing of the descriptor here */
> +		ret = ismt_process_desc(desc, data, priv->dma_buffer, size);
> +	else if (ret == 0) {
> +		dev_err(dev, "completion wait timed out\n");
> +		ret = -ETIMEDOUT;
> +	} else {
> +		dev_err(dev, "completion wait interrupted\n");
> +		ret = -EIO;
> +	}
> +
> +	/* Update the ring pointer */
> +	priv->head++;
> +	priv->head %= ISMT_DESC_ENTRIES;
> +
> +	return ret;
> +}
> +
> +/**
> + * ismt_func() - report which i2c commands are supported by this
> +adapter
> + * @adap: the i2c host adapter
> + */
> +static u32 ismt_func(struct i2c_adapter *adap) {
> +	return I2C_FUNC_SMBUS_QUICK		|
> +		I2C_FUNC_SMBUS_BYTE		|
> +		I2C_FUNC_SMBUS_BYTE_DATA	|
> +		I2C_FUNC_SMBUS_WORD_DATA	|
> +		I2C_FUNC_SMBUS_PROC_CALL	|
> +		I2C_FUNC_SMBUS_BLOCK_DATA	|
> +		I2C_FUNC_SMBUS_PEC;
> +}
> +
> +/**
> + * smbus_algorithm - the adapter algorithm and supported functionality
> + * @smbus_xfer: the adapter algorithm
> + * @functionality: functionality supported by the adapter  */ static
> +const struct i2c_algorithm smbus_algorithm = {
> +	.smbus_xfer	= ismt_access,
> +	.functionality	= ismt_func,
> +};
> +
> +/**
> + * ismt_handle_isr() - interrupt handler bottom half
> + * @priv: iSMT private data
> + */
> +static irqreturn_t ismt_handle_isr(struct ismt_priv *priv) {
> +	complete(&priv->cmp);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +
> +/**
> + * ismt_do_interrupt() - IRQ interrupt handler
> + * @vec: interrupt vector
> + * @data: iSMT private data
> + */
> +static irqreturn_t ismt_do_interrupt(int vec, void *data) {
> +	u32 val;
> +	struct ismt_priv *priv = data;
> +
> +	/*
> +	 * check to see it's our interrupt, return IRQ_NONE if not ours
> +	 * since we are sharing interrupt
> +	 */
> +	val = readl(priv->smba + ISMT_MSTR_MSTS);
> +
> +	if (!(val & (ISMT_MSTS_MIS | ISMT_MSTS_MEIS)))
> +		return IRQ_NONE;
> +	else
> +		writel(val | ISMT_MSTS_MIS | ISMT_MSTS_MEIS,
> +		       priv->smba + ISMT_MSTR_MSTS);
> +
> +	return ismt_handle_isr(priv);
> +}
> +
> +/**
> + * ismt_do_msi_interrupt() - MSI interrupt handler
> + * @vec: interrupt vector
> + * @data: iSMT private data
> + */
> +static irqreturn_t ismt_do_msi_interrupt(int vec, void *data) {
> +	return ismt_handle_isr(data);
> +}
> +
> +/**
> + * ismt_hw_init() - initialize the iSMT hardware
> + * @priv: iSMT private data
> + */
> +static void __devinit ismt_hw_init(struct ismt_priv *priv) {
> +	u32 val;
> +	struct device *dev = &priv->pci_dev->dev;
> +
> +	/* initialize the Master Descriptor Base Address (MDBA) */
> +	writel(priv->io_rng_dma, priv->smba + ISMT_MSTR_MDBA);
> +	writel(priv->io_rng_dma >> 32, priv->smba + ISMT_MSTR_MDBA +
> 4);
> +
> +	/* initialize the Master Control Register (MCTRL) */
> +	writel(ISMT_MCTRL_MEIE, priv->smba + ISMT_MSTR_MCTRL);
> +
> +	/* initialize the Master Status Register (MSTS) */
> +	writel(0, priv->smba + ISMT_MSTR_MSTS);
> +
> +	/* initialize the Master Descriptor Size (MDS) */
> +	val = readl(priv->smba + ISMT_MSTR_MDS);
> +	writel((val & ~ISMT_MDS_MASK) | (ISMT_DESC_ENTRIES - 1),
> +		priv->smba + ISMT_MSTR_MDS);
> +
> +	/*
> +	 * Set the SMBus speed (could use this for slow HW debuggers)
> +	 */
> +
> +	val = readl(priv->smba + ISMT_SPGT);
> +
> +	switch (bus_speed) {
> +	case 0:
> +		break;
> +
> +	case 1:
> +		dev_dbg(dev, "Setting SMBus clock to 80kHz\n");
> +		writel(((val & ~ISMT_SPGT_SPD_MASK) |
> ISMT_SPGT_SPD_80K),
> +			priv->smba + ISMT_SPGT);
> +		break;
> +
> +	case 2:
> +		dev_dbg(dev, "Setting SMBus clock to 100kHz\n");
> +		writel(((val & ~ISMT_SPGT_SPD_MASK) |
> ISMT_SPGT_SPD_100K),
> +			priv->smba + ISMT_SPGT);
> +		break;
> +
> +	case 3:
> +		dev_dbg(dev, "Setting SMBus clock to 400kHz\n");
> +		writel(((val & ~ISMT_SPGT_SPD_MASK) |
> ISMT_SPGT_SPD_400K),
> +			priv->smba + ISMT_SPGT);
> +		break;
> +
> +	case 4:
> +		dev_dbg(dev, "Setting SMBus clock to 1MHz\n");
> +		writel(((val & ~ISMT_SPGT_SPD_MASK) |
> ISMT_SPGT_SPD_1M),
> +			priv->smba + ISMT_SPGT);
> +		break;
> +
> +	default:
> +		dev_dbg(dev, "Invalid SMBus clock speed, only 1-4 are
> valid\n");
> +		break;
> +	}
> +}
> +
> +/**
> + * ismt_dev_init() - initialize the iSMT data structures
> + * @priv: iSMT private data
> + */
> +static int __devinit ismt_dev_init(struct ismt_priv *priv) {
> +	/* allocate memory for the descriptor */
> +	priv->hw = dmam_alloc_coherent(&priv->pci_dev->dev,
> +				       (ISMT_DESC_ENTRIES
> +					       * sizeof(struct ismt_desc)),
> +				       &priv->io_rng_dma,
> +				       GFP_KERNEL);
> +	if (!priv->hw)
> +		return -ENOMEM;
> +
> +	memset(priv->hw, 0, (ISMT_DESC_ENTRIES * sizeof(struct
> ismt_desc)));
> +
> +	priv->head = 0;
> +	init_completion(&priv->cmp);
> +
> +	return 0;
> +}
> +
> +/**
> + * ismt_int_init() - initialize interrupts
> + * @priv: iSMT private data
> + */
> +static int __devinit ismt_int_init(struct ismt_priv *priv) {
> +	int err;
> +
> +	/* Try using MSI interrupts */
> +	err = pci_enable_msi(priv->pci_dev);
> +
> +	if (err) {
> +		dev_warn(&priv->pci_dev->dev,
> +			 "Unable to use MSI interrupts, falling back to
> legacy");
> +		goto intx;
> +	}
> +
> +	err = devm_request_irq(&priv->pci_dev->dev,
> +			       priv->pci_dev->irq,
> +			       ismt_do_msi_interrupt,
> +			       0,
> +			       "ismt-msi",
> +			       priv);
> +
> +	if (err) {
> +		pci_disable_msi(priv->pci_dev);
> +		goto intx;
> +	}
> +
> +	priv->using_msi = true;
> +	goto done;
> +
> +	/* Try using legacy interrupts */
> +intx:
> +	err = devm_request_irq(&priv->pci_dev->dev,
> +			       priv->pci_dev->irq,
> +			       ismt_do_interrupt,
> +			       IRQF_SHARED,
> +			       "ismt-intx",
> +			       priv);
> +	if (err) {
> +		dev_err(&priv->pci_dev->dev, "no usable interrupts\n");
> +		return -ENODEV;
> +	}
> +
> +	priv->using_msi = false;
> +
> +done:
> +	return 0;
> +}
> +
> +static struct pci_driver ismt_driver;
> +
> +/**
> + * ismt_probe() - probe for iSMT devices
> + * @pdev: PCI-Express device
> + * @id: PCI-Express device ID
> + */
> +static int __devinit
> +ismt_probe(struct pci_dev *pdev, const struct pci_device_id *id) {
> +	int err;
> +	struct ismt_priv *priv;
> +	unsigned long start, len;
> +
> +	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	pci_set_drvdata(pdev, priv);
> +	i2c_set_adapdata(&priv->adapter, priv);
> +	priv->adapter.owner = THIS_MODULE;
> +
> +	priv->adapter.class = I2C_CLASS_HWMON;
> +
> +	priv->adapter.algo = &smbus_algorithm;
> +
> +	/* set up the sysfs linkage to our parent device */
> +	priv->adapter.dev.parent = &pdev->dev;
> +
> +	/* number of retries on lost arbitration */
> +	priv->adapter.retries = ISMT_MAX_RETRIES;
> +
> +	priv->pci_dev = pdev;
> +
> +	err = pcim_enable_device(pdev);
> +	if (err) {
> +		dev_err(&pdev->dev, "Failed to enable SMBus PCI device
> (%d)\n",
> +			err);
> +		return err;
> +	}
> +
> +	/* enable bus mastering */
> +	pci_set_master(pdev);
> +
> +	/* Determine the address of the SMBus area */
> +	start = pci_resource_start(pdev, SMBBAR);
> +	len = pci_resource_len(pdev, SMBBAR);
> +	if (!start || !len) {
> +		dev_err(&pdev->dev,
> +			"SMBus base address uninitialized, upgrade BIOS\n");
> +		return -ENODEV;
> +	}
> +
> +	snprintf(priv->adapter.name, sizeof(priv->adapter.name),
> +		 "SMBus iSMT adapter at %lx", start);
> +
> +	dev_dbg(&priv->pci_dev->dev, " start=0x%lX\n", start);
> +	dev_dbg(&priv->pci_dev->dev, " len=0x%lX\n", len);
> +
> +	err = acpi_check_resource_conflict(&pdev->resource[SMBBAR]);
> +	if (err) {
> +		dev_err(&pdev->dev, "ACPI resource conflict!\n");
> +		return err;
> +	}
> +
> +	err = pci_request_region(pdev, SMBBAR, ismt_driver.name);
> +	if (err) {
> +		dev_err(&pdev->dev,
> +			"Failed to request SMBus region 0x%lx-0x%lx\n",
> +			start, start + len);
> +		return err;
> +	}
> +
> +	priv->smba = pcim_iomap(pdev, SMBBAR, len);
> +	if (!priv->smba) {
> +		dev_err(&pdev->dev, "Unable to ioremap SMBus BAR\n");
> +		err = -ENODEV;
> +		goto fail;
> +	}
> +
> +	if ((pci_set_dma_mask(pdev, DMA_BIT_MASK(64)) != 0) ||
> +	    (pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64)) != 0))
> {
> +		if ((pci_set_dma_mask(pdev, DMA_BIT_MASK(32)) != 0) ||
> +		   (pci_set_consistent_dma_mask(pdev,
> DMA_BIT_MASK(32)) != 0)) {
> +			dev_warn(&pdev->dev, "pci_set_dma_mask fail
> %p\n",
> +				 pdev);
> +			goto fail;
> +		}
> +	}
> +
> +	err = ismt_dev_init(priv);
> +	if (err)
> +		goto fail;
> +
> +	ismt_hw_init(priv);
> +
> +	err = ismt_int_init(priv);
> +	if (err)
> +		goto fail;
> +
> +	err = i2c_add_adapter(&priv->adapter);
> +	if (err) {
> +		dev_err(&pdev->dev, "Failed to add SMBus iSMT
> adapter\n");
> +		err = -ENODEV;
> +		goto fail;
> +	}
> +	return 0;
> +
> +fail:
> +	pci_release_region(pdev, SMBBAR);
> +	return err;
> +}
> +
> +/**
> + * ismt_remove() - release driver resources
> + * @pdev: PCI-Express device
> + */
> +static void __devexit ismt_remove(struct pci_dev *pdev) {
> +	struct ismt_priv *priv = pci_get_drvdata(pdev);
> +
> +	i2c_del_adapter(&priv->adapter);
> +	pci_release_region(pdev, SMBBAR);
> +}
> +
> +/**
> + * ismt_suspend() - place the device in suspend
> + * @pdev: PCI-Express device
> + * @mesg: PM message
> + */
> +#ifdef CONFIG_PM
> +static int ismt_suspend(struct pci_dev *pdev, pm_message_t mesg) {
> +	pci_save_state(pdev);
> +	pci_set_power_state(pdev, pci_choose_state(pdev, mesg));
> +	return 0;
> +}
> +
> +/**
> + * ismt_resume() - PCI resume code
> + * @pdev: PCI-Express device
> + */
> +static int ismt_resume(struct pci_dev *pdev) {
> +	pci_set_power_state(pdev, PCI_D0);
> +	pci_restore_state(pdev);
> +	return pci_enable_device(pdev);
> +}
> +
> +#else
> +
> +#define ismt_suspend NULL
> +#define ismt_resume NULL
> +
> +#endif
> +
> +static struct pci_driver ismt_driver = {
> +	.name = "ismt_smbus",
> +	.id_table = ismt_ids,
> +	.probe = ismt_probe,
> +	.remove = __devexit_p(ismt_remove),
> +	.suspend = ismt_suspend,
> +	.resume = ismt_resume,
> +};
> +
> +module_pci_driver(ismt_driver);
> +
> +MODULE_LICENSE("Dual BSD/GPL");
> +MODULE_AUTHOR("Bill E. Brown <bill.e.brown@xxxxxxxxx>");
> +MODULE_DESCRIPTION("Intel SMBus Message Transport (iSMT) driver");
> --
> 1.6.2.5
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body
> of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at
> http://vger.kernel.org/majordomo-info.html

--
To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux GPIO]     [Linux SPI]     [Linux Hardward Monitoring]     [LM Sensors]     [Linux USB Devel]     [Linux Media]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux