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.
Signed-off-by: Bill Brown <bill.e.brown@xxxxxxxxx>
---
drivers/i2c/busses/Kconfig | 10 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-ismt.c | 845 +++++++++++++++++++++++++++++++++++++++++
drivers/i2c/busses/i2c-ismt.h | 111 ++++++
4 files changed, 967 insertions(+), 0 deletions(-)
create mode 100644 drivers/i2c/busses/i2c-ismt.c
create mode 100644 drivers/i2c/busses/i2c-ismt.h
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..694711a 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_I2C_SIS630) += i2c-sis630.o
obj-$(CONFIG_I2C_SIS96X) += i2c-sis96x.o
obj-$(CONFIG_I2C_VIA) += i2c-via.o
obj-$(CONFIG_I2C_VIAPRO) += i2c-viapro.o
+obj-$(CONFIG_I2C_ISMT) += i2c-ismt.o
# Mac SMBus host controller drivers
obj-$(CONFIG_I2C_HYDRA) += i2c-hydra.o
diff --git a/drivers/i2c/busses/i2c-ismt.c b/drivers/i2c/busses/i2c-ismt.c
new file mode 100644
index 0000000..46df042
--- /dev/null
+++ b/drivers/i2c/busses/i2c-ismt.c
@@ -0,0 +1,845 @@
+/*
+ * This file is provided under a dual BSD/GPLv2 license. When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2012 Intel Corporation. All rights reserved.
+ *
+ * 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
+ *
+ * Copyright(c) 2012 Intel Corporation. All rights reserved.
+ * All rights reserved.
+ *
+ * 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) on the following Intel SOCs:
+ BWD
+ CTN
+
+ Features supported by this driver:
+ Software PEC no
+ 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/delay.h>
+#include <linux/i2c.h>
+#include <linux/acpi.h>
+#include <linux/interrupt.h>
+#include "i2c-ismt.h"
+
+/**
+ * DEFINE_PCI_DEVICE_TABLE - 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_BWD_SMBUS_SMT0) },
+ { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_BWD_SMBUS_SMT1) },
+ { 0, }
+};
+
+MODULE_DEVICE_TABLE(pci, ismt_ids);
+
+/* Master Descriptor control bits */
+static unsigned int stop_on_error = 1;
+module_param(stop_on_error, uint, S_IRUGO);
+MODULE_PARM_DESC(stop_on_error, "Stop on Error");
+
+static unsigned int fair = 1;
+module_param(fair, uint, S_IRUGO);
+MODULE_PARM_DESC(fair, "Enable fairness on the SMBus");
+
+#ifdef DEBUG
+/**
+ * ismt_desc_dump() - dump the contents of a descriptor for debug purposes
+ * @adap: the I2C host adapter
+ */
+static void ismt_desc_dump(struct i2c_adapter *adap)
+{
+ struct ismt_priv *priv = i2c_get_adapdata(adap);
+ 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
+ * @adap: the I2C host adapter
+ */
+static void ismt_gen_reg_dump(struct i2c_adapter *adap)
+{
+ struct ismt_priv *priv = i2c_get_adapdata(adap);
+ 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
+ * @adap: the I2C host adapter
+ */
+static void ismt_mstr_reg_dump(struct i2c_adapter *adap)
+{
+ struct ismt_priv *priv = i2c_get_adapdata(adap);
+ 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));
+}
+
+#else
+static void ismt_desc_dump(struct i2c_adapter *adap) {}
+static void ismt_gen_reg_dump(struct i2c_adapter *adap) {}
+static void ismt_mstr_reg_dump(struct i2c_adapter *adap) {}
+#endif
+
+/**
+ * ismt_insert_cmd() - stuff a command into the head of the data buffer
+ * @data: data buffer
+ * @command: command to insert
+ */
+static void ismt_insert_cmd(union i2c_smbus_data *data, u8 command)
+{
+ memmove(&data->block[1], &data->block[0], I2C_SMBUS_BLOCK_MAX);
+ data->block[0] = command;
+}
+
+/**
+ * ismt_submit_desc() - add a descriptor to the ring
+ * @adap: the i2c host adapter
+ */
+static void ismt_submit_desc(struct i2c_adapter *adap)
+{
+ int fmhp;
+ int val;
+ struct ismt_priv *priv = i2c_get_adapdata(adap);
+
+ ismt_desc_dump(adap);
+ ismt_gen_reg_dump(adap);
+ ismt_mstr_reg_dump(adap);
+
+ /* 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
+ * @adap: the i2c host adapter
+ */
+static int ismt_process_desc(struct i2c_adapter *adap)
+{
+ struct ismt_desc *desc;
+ struct ismt_priv *priv = i2c_get_adapdata(adap);
+
+ desc = &priv->hw[priv->head];
+
+ if (desc->status & ISMT_DESC_SCS)
+ return 0;
+
+ if ((desc->status & ISMT_DESC_NAK) || (desc->status & ISMT_DESC_CRC))
+ return -ENXIO;
+
+ if (desc->status & ISMT_DESC_COL)
+ return -EAGAIN;
+
+ return 0;
+}
+
+/**
+ * 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)
+{
+ unsigned int ret = 0; /* return code */
+ dma_addr_t dma_addr = 0; /* address of the data buffer */
+ u8 dma_size = 0;
+ enum dma_data_direction dma_direction = 0;
+ bool map_dma_flag = 0;
+ struct ismt_desc *desc;
+ struct ismt_priv *priv = i2c_get_adapdata(adap);
+
+ 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);
+
+ /* Initialize common control bits */
+ desc->control |= ISMT_DESC_INT;
+
+ if (stop_on_error)
+ desc->control |= ISMT_DESC_SOE;
+
+ if ((flags & I2C_CLIENT_PEC) && (size != I2C_SMBUS_QUICK)
+ && (size != I2C_SMBUS_I2C_BLOCK_DATA))
+ desc->control |= ISMT_DESC_PEC;
+
+ if (fair)
+ desc->control |= ISMT_DESC_FAIR;
+
+ switch (size) {
+ case I2C_SMBUS_QUICK:
+ dev_dbg(&priv->pci_dev->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(&priv->pci_dev->dev, "I2C_SMBUS_BYTE: WRITE\n");
+ desc->control |= ISMT_DESC_CWRL;
+ desc->wr_len_cmd = command;
+ } else {
+ /* Receive Byte */
+ dev_dbg(&priv->pci_dev->dev, "I2C_SMBUS_BYTE: READ\n");
+ dma_size = 1;
+ dma_direction = DMA_FROM_DEVICE;
+ map_dma_flag = 1;
+ 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(&priv->pci_dev->dev, "I2C_SMBUS_BYTE_DATA: WRITE\n");
+ desc->wr_len_cmd = 2;
+
+ /* Stuff the command ahead of the data in the buffer */
+ ismt_insert_cmd(data, command);
+ dma_size = 2;
+ dma_direction = DMA_TO_DEVICE;
+ } else {
+ /* Read Byte */
+ dev_dbg(&priv->pci_dev->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;
+ }
+
+ map_dma_flag = 1;
+ break;
+
+ case I2C_SMBUS_WORD_DATA:
+ if (read_write == I2C_SMBUS_WRITE) {
+ /* Write Word */
+ dev_dbg(&priv->pci_dev->dev, "I2C_SMBUS_WORD_DATA: WRITE\n");
+ desc->wr_len_cmd = 3;
+
+ /* Stuff the command ahead of the data in the buffer */
+ ismt_insert_cmd(data, command);
+ dma_size = 3;
+ dma_direction = DMA_TO_DEVICE;
+ } else {
+ /* Read Word */
+ dev_dbg(&priv->pci_dev->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;
+ }
+
+ map_dma_flag = 1;
+ break;
+
+ case I2C_SMBUS_PROC_CALL:
+ dev_dbg(&priv->pci_dev->dev, "I2C_SMBUS_PROC_CALL\n");
+ desc->wr_len_cmd = 3;
+ desc->rd_len = 2;
+
+ /* Stuff the command ahead of the data in the buffer */
+ ismt_insert_cmd(data, command);
+ dma_size = 3;
+ dma_direction = DMA_BIDIRECTIONAL;
+ map_dma_flag = 1;
+ break;
+
+ case I2C_SMBUS_BLOCK_DATA:
+ if (read_write == I2C_SMBUS_WRITE) {
+ /* Block Write */
+ dev_dbg(&priv->pci_dev->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;
+ ismt_insert_cmd(data, command);
+ } else {
+ /* Block Read */
+ dev_dbg(&priv->pci_dev->dev, "I2C_SMBUS_BLOCK_DATA: READ\n");
+ dma_size = data->block[0] + 1;
+ dma_direction = DMA_FROM_DEVICE;
+ desc->rd_len = dma_size;
+ desc->wr_len_cmd = command;
+ desc->control |= (ISMT_DESC_BLK | ISMT_DESC_CWRL);
+ }
+
+ map_dma_flag = 1;
+ break;
+
+ default:
+ dev_err(&priv->pci_dev->dev, "Unsupported transaction %d\n",
+ size);
+ return -EOPNOTSUPP;
+ }
+
+ /* map the data buffer */
+ if (map_dma_flag) {
+ dev_dbg(&priv->pci_dev->dev,
+ " &priv->pci_dev->dev=%p\n", &priv->pci_dev->dev);
+ dev_dbg(&priv->pci_dev->dev, " data=%p\n", data);
+ dev_dbg(&priv->pci_dev->dev, " dma_size=%d\n", dma_size);
+ dev_dbg(&priv->pci_dev->dev,
+ " dma_direction=%d\n", dma_direction);
+
+ dma_addr = dma_map_single(&priv->pci_dev->dev,
+ data,
+ dma_size,
+ dma_direction);
+
+ dev_dbg(&priv->pci_dev->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(adap);
+
+ /* Now we wait for interrupt completion, 1s */
+ ret = wait_for_completion_interruptible_timeout(&priv->cmp, HZ*1);
+
+ /* unmap the data buffer */
+ if (map_dma_flag)
+ dma_unmap_single(&adap->dev, dma_addr, dma_size, dma_direction);
+
+ if (ret < 0) {
+ dev_err(&priv->pci_dev->dev, "completion wait interrupted\n");
+ ret = -EIO;
+ } else if (ret == 0) {
+ dev_err(&priv->pci_dev->dev, "completion wait timed out\n");
+ ret = -ETIMEDOUT;
+ } else
+ /* do any post processing of the descriptor here */
+ ret = ismt_process_desc(adap);
+
+ /* 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;
+}
+
+/**
+ * struct i2c_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 = (struct ismt_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;
+
+ if (val & ISMT_MSTS_MIS) {
+ /* completed successfully */
+ writel((val | ISMT_MSTS_MIS), priv->smba + ISMT_MSTR_MSTS);
+ } else {
+ /* completed with errors */
+ writel((val | 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)
+{
+ struct ismt_priv *priv = (struct ismt_priv *)data;
+
+ return ismt_handle_isr(priv);
+}
+
+/**
+ * ismt_hw_init() - initialize the iSMT hardware
+ * @pdev: PCI-Express device
+ */
+static void __devinit ismt_hw_init(struct pci_dev *pdev)
+{
+ u32 val;
+ struct ismt_priv *priv = pci_get_drvdata(pdev);
+
+ /* initialize the Master Descriptor Base Address (MDBA) */
+ writeq(priv->io_rng_dma, priv->smba + ISMT_MSTR_MDBA);
+
+ /* 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_MDS)) | (ISMT_DESC_ENTRIES - 1),
+ priv->smba + ISMT_MSTR_MDS);
+
+#ifdef DEBUG_SLOW_HW
+ /*
+ * initialize the SMBus speed to 80KHz for slow HW debuggers
+ */
+ dev_dbg(&pdev->dev, " Setting SMBus clock to 80KHz\n");
+ val = readl(priv->smba + ISMT_SPGT);
+ writel(((val & ~(ISMT_SPGT_SPD)) | ISMT_SPGT_SPD_80K),
+ priv->smba + ISMT_SPGT);
+#endif
+
+ dev_dbg(&pdev->dev, " priv->smba=%p\n", priv->smba);
+}
+
+/**
+ * ismt_init() - initialize the iSMT data structures
+ * @pdev: PCI-Express Device
+ */
+static int __devinit ismt_init(struct pci_dev *pdev)
+{
+ struct ismt_priv *priv = pci_get_drvdata(pdev);
+
+ priv->entries = ISMT_DESC_ENTRIES;
+
+ /* allocate memory for the descriptor */
+ priv->hw = dmam_alloc_coherent(&pdev->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;
+ priv->tail = 0;
+ init_completion(&priv->cmp);
+
+ return 0;
+}
+
+/**
+ * ismt_int_init() - initialize interrupts
+ * @pdev: PCI-Express device
+ * @priv: iSMT private data
+ */
+static int __devinit ismt_int_init(struct pci_dev *pdev, struct ismt_priv *priv)
+{
+ int err;
+
+ /* Try using MSI interrupts */
+ err = pci_enable_msi(pdev);
+ if (err)
+ goto intx;
+
+ err = devm_request_irq(&pdev->dev,
+ pdev->irq,
+ ismt_do_msi_interrupt,
+ 0,
+ "ismt-msi",
+ priv);
+
+ if (err) {
+ pci_disable_msi(pdev);
+ goto intx;
+ }
+
+ goto done;
+
+ /* Try using legacy interrupts */
+intx:
+ err = devm_request_irq(&pdev->dev,
+ pdev->irq,
+ ismt_do_interrupt,
+ IRQF_SHARED,
+ "ismt-intx",
+ priv);
+ if (err) {
+ dev_err(&pdev->dev, "no usable interrupts\n");
+ return -ENODEV;
+ }
+
+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;
+ 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);
+ if (!start) {
+ dev_err(&pdev->dev,
+ "SMBus base address uninitialized, upgrade BIOS\n");
+ return -ENODEV;
+ }
+
+ len = pci_resource_len(pdev, SMBBAR);
+ if (len == 0) {
+ dev_err(&pdev->dev,
+ "SMBus base address uninitialized, upgrade BIOS\n");
+ return -ENODEV;
+ }
+
+ 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;
+ }
+
+ err = pci_set_dma_mask(pdev, DMA_BIT_MASK(64));
+ if (err) {
+ err = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
+ if (err)
+ goto fail;
+ dev_warn(&pdev->dev, "Cannot DMA highmem\n");
+ }
+
+ err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64));
+ if (err) {
+ err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
+ if (err)
+ goto fail;
+ dev_warn(&pdev->dev, "Cannot DMA consistent highmem\n");
+ }
+
+ err = ismt_init(pdev);
+ if (err) {
+ err = -ENODEV;
+ goto fail;
+ }
+
+ ismt_hw_init(pdev);
+
+ err = ismt_int_init(pdev, priv);
+ if (err)
+ goto fail;
+
+ /* 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;
+
+ snprintf(priv->adapter.name, sizeof(priv->adapter.name),
+ "SMBus iSMT adapter at %p", priv->smba);
+ 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);
+
+ writel(ISMT_GCTRL_SRST, priv->smba + ISMT_GR_GCTRL);
+ 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,
+};
+
+/**
+ * i2c_ismt_init() - iSMT driver initialization
+ */
+static int __init i2c_ismt_init(void)
+{
+ pr_debug("Loading the iSMT SMBus driver\n");
+ return pci_register_driver(&ismt_driver);
+}
+
+/**
+ * i2c_ismt_exit() - iSMT driver exit code
+ */
+static void __exit i2c_ismt_exit(void)
+{
+ pr_debug("Unloading iSMT SMBus driver\n");
+ pci_unregister_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");
+
+module_init(i2c_ismt_init);
+module_exit(i2c_ismt_exit);
+
diff --git a/drivers/i2c/busses/i2c-ismt.h b/drivers/i2c/busses/i2c-ismt.h
new file mode 100644
index 0000000..e9c10e1
--- /dev/null
+++ b/drivers/i2c/busses/i2c-ismt.h
@@ -0,0 +1,111 @@
+#ifndef _I2C_ISMT_H_
+#define _I2C_ISMT_H_
+
+/* PCI Address Constants */
+#define SMBBAR 0
+
+/* PCI DIDs for Briarwood's pair of SMBus Message Transport (SMT) Devices */
+#define PCI_DEVICE_ID_INTEL_BWD_SMBUS_SMT0 0x0c59
+#define PCI_DEVICE_ID_INTEL_BWD_SMBUS_SMT1 0x0c5a
+
+#define ISMT_DESC_ENTRIES 32 /* number of descritor 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 */
+
+/* Hardware Descriptor Masks */
+#define ISMT_DESC_ADDR 0x7f /* I2C/SMB address mask */
+#define ISMT_DESC_RW 0x01 /* Read/Write bit mask */
+
+/* Macros */
+#define ISMT_DESC_ADDR_RW(addr, rw) (((addr & ISMT_DESC_ADDR) << 1) \
+ | (rw & ISMT_DESC_RW))
+
+/* iSMT General Register address offsets (SMBAR + <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 Pointer (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 Interrupt Status (MEIS) */
+#define ISMT_MSTS_IP 0x01 /* In Progress */
+
+/* Master Descriptor Size (MDS) bit definitions */
+#define ISMT_MDS_MDS 0xFF /* Master Descriptor Size mask (MDS) */
+
+/* SMBus PHY Global Timing Register (SPGT) bit definitions */
+#define ISMT_SPGT_SPD 0xc0000000 /* SMBus Speed mask */
+#define ISMT_SPGT_SPD_80K (0x01 << 30) /* 80 KHz */
+
+/* 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 */
+};
+
+struct ismt_priv {
+ struct i2c_adapter adapter;
+ void *smba; /* PCI BAR */
+ struct pci_dev *pci_dev;
+ struct ismt_ring_ent **ring; /* housekeeping struct pointer */
+ struct ismt_desc *hw; /* virtual base address of the descriptor */
+ dma_addr_t io_rng_dma; /* hardware base address of the descriptor */
+ int entries; /* number of descriptor entries */
+ u8 head; /* ring buffer head pointer */
+ u8 tail; /* ring buffer tail pointer */
+ struct completion cmp; /* interrupt completion */
+};
+
+#endif
--
1.6.2.5
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