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kernel_optimize_test/drivers/i2c/busses/i2c-ismt.c
Radu Rendec 5cd5f0bb0d i2c: ismt: 16-byte align the DMA buffer address 
Use only a portion of the data buffer for DMA transfers, which is always
16-byte aligned. This makes the DMA buffer address 16-byte aligned and
compensates for spurious hardware parity errors that may appear when the
DMA buffer address is not 16-byte aligned.

The data buffer is enlarged in order to accommodate any possible 16-byte
alignment offset and changes the DMA code to only use a portion of the
data buffer, which is 16-byte aligned.

The symptom of the hardware issue is the same as the one addressed in
v3.12-rc2-5-gbf41691 and manifests by transfers failing with EIO, with
bit 9 being set in the ERRSTS register.

Signed-off-by: Radu Rendec <radu.rendec@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-01-15 21:02:43 +01:00

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/*
* 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.
* 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/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>
#include <linux/io-64-nonatomic-lo-hi.h>
/* PCI Address Constants */
#define SMBBAR 0
/* PCI DIDs for the Intel SMBus Message Transport (SMT) Devices */
#define PCI_DEVICE_ID_INTEL_S1200_SMT0 0x0c59
#define PCI_DEVICE_ID_INTEL_S1200_SMT1 0x0c5a
#define PCI_DEVICE_ID_INTEL_DNV_SMT 0x19ac
#define PCI_DEVICE_ID_INTEL_AVOTON_SMT 0x1f15
#define ISMT_DESC_ENTRIES 2 /* 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 __iomem *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 buffer[I2C_SMBUS_BLOCK_MAX + 16]; /* temp R/W data buffer */
};
/**
* ismt_ids - PCI device IDs supported by this driver
*/
static const struct pci_device_id ismt_ids[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT0) },
{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT1) },
{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_DNV_SMT) },
{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_AVOTON_SMT) },
{ 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 in kHz (0 = BIOS default)");
/**
* __ismt_desc_dump() - dump the contents of a specific descriptor
*/
static void __ismt_desc_dump(struct device *dev, const struct ismt_desc *desc)
{
dev_dbg(dev, "Descriptor struct: %p\n", desc);
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_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);
__ismt_desc_dump(dev, desc);
}
/**
* 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%016llX\n",
priv->smba + ISMT_GR_SMTICL,
(long long unsigned int)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%016llX\n",
priv->smba + ISMT_MSTR_MDBA,
(long long unsigned int)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));
}
/**
* 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
* @priv: ismt_priv struct holding our dma buffer
* @size: SMBus transaction type
* @read_write: flag to indicate if this is a read or write
*/
static int ismt_process_desc(const struct ismt_desc *desc,
union i2c_smbus_data *data,
struct ismt_priv *priv, int size,
char read_write)
{
u8 *dma_buffer = PTR_ALIGN(&priv->buffer[0], 16);
dev_dbg(&priv->pci_dev->dev, "Processing completed descriptor\n");
__ismt_desc_dump(&priv->pci_dev->dev, desc);
ismt_gen_reg_dump(priv);
ismt_mstr_reg_dump(priv);
if (desc->status & ISMT_DESC_SCS) {
if (read_write == I2C_SMBUS_WRITE &&
size != I2C_SMBUS_PROC_CALL)
return 0;
switch (size) {
case I2C_SMBUS_BYTE:
case I2C_SMBUS_BYTE_DATA:
data->byte = dma_buffer[0];
break;
case I2C_SMBUS_WORD_DATA:
case I2C_SMBUS_PROC_CALL:
data->word = dma_buffer[0] | (dma_buffer[1] << 8);
break;
case I2C_SMBUS_BLOCK_DATA:
if (desc->rxbytes != dma_buffer[0] + 1)
return -EMSGSIZE;
memcpy(data->block, dma_buffer, desc->rxbytes);
break;
case I2C_SMBUS_I2C_BLOCK_DATA:
memcpy(&data->block[1], dma_buffer, desc->rxbytes);
data->block[0] = desc->rxbytes;
break;
}
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;
unsigned long time_left;
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;
u8 *dma_buffer = PTR_ALIGN(&priv->buffer[0], 16);
desc = &priv->hw[priv->head];
/* Initialize the DMA buffer */
memset(priv->buffer, 0, sizeof(priv->buffer));
/* Initialize the descriptor */
memset(desc, 0, sizeof(struct ismt_desc));
desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(addr, read_write);
/* Initialize common control bits */
if (likely(pci_dev_msi_enabled(priv->pci_dev)))
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;
dma_buffer[0] = command;
dma_buffer[1] = data->byte;
} 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;
dma_buffer[0] = command;
dma_buffer[1] = data->word & 0xff;
dma_buffer[2] = data->word >> 8;
} 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;
dma_buffer[0] = command;
dma_buffer[1] = data->word & 0xff;
dma_buffer[2] = data->word >> 8;
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;
dma_buffer[0] = command;
memcpy(&dma_buffer[1], &data->block[1], dma_size - 1);
} 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;
case I2C_SMBUS_I2C_BLOCK_DATA:
/* Make sure the length is valid */
if (data->block[0] < 1)
data->block[0] = 1;
if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
data->block[0] = I2C_SMBUS_BLOCK_MAX;
if (read_write == I2C_SMBUS_WRITE) {
/* i2c Block Write */
dev_dbg(dev, "I2C_SMBUS_I2C_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_I2C;
dma_buffer[0] = command;
memcpy(&dma_buffer[1], &data->block[1], dma_size - 1);
} else {
/* i2c Block Read */
dev_dbg(dev, "I2C_SMBUS_I2C_BLOCK_DATA: READ\n");
dma_size = data->block[0];
dma_direction = DMA_FROM_DEVICE;
desc->rd_len = dma_size;
desc->wr_len_cmd = command;
desc->control |= (ISMT_DESC_I2C | ISMT_DESC_CWRL);
/*
* Per the "Table 15-15. I2C Commands",
* in the External Design Specification (EDS),
* (Document Number: 508084, Revision: 2.0),
* the _rw bit must be 0
*/
desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(addr, 0);
}
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", 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(dev,
dma_buffer,
dma_size,
dma_direction);
if (dma_mapping_error(dev, dma_addr)) {
dev_err(dev, "Error in mapping dma buffer %p\n",
dma_buffer);
return -EIO;
}
dev_dbg(dev, " dma_addr = %pad\n", &dma_addr);
desc->dptr_low = lower_32_bits(dma_addr);
desc->dptr_high = upper_32_bits(dma_addr);
}
reinit_completion(&priv->cmp);
/* Add the descriptor */
ismt_submit_desc(priv);
/* Now we wait for interrupt completion, 1s */
time_left = wait_for_completion_timeout(&priv->cmp, HZ*1);
/* unmap the data buffer */
if (dma_size != 0)
dma_unmap_single(dev, dma_addr, dma_size, dma_direction);
if (unlikely(!time_left)) {
dev_err(dev, "completion wait timed out\n");
ret = -ETIMEDOUT;
goto out;
}
/* do any post processing of the descriptor here */
ret = ismt_process_desc(desc, data, priv, size, read_write);
out:
/* 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_I2C_BLOCK |
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 ismt_hw_init(struct ismt_priv *priv)
{
u32 val;
struct device *dev = &priv->pci_dev->dev;
/* 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_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 80:
dev_dbg(dev, "Setting SMBus clock to 80 kHz\n");
writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_80K),
priv->smba + ISMT_SPGT);
break;
case 100:
dev_dbg(dev, "Setting SMBus clock to 100 kHz\n");
writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_100K),
priv->smba + ISMT_SPGT);
break;
case 400:
dev_dbg(dev, "Setting SMBus clock to 400 kHz\n");
writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_400K),
priv->smba + ISMT_SPGT);
break;
case 1000:
dev_dbg(dev, "Setting SMBus clock to 1000 kHz\n");
writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_1M),
priv->smba + ISMT_SPGT);
break;
default:
dev_warn(dev, "Invalid SMBus clock speed, only 0, 80, 100, 400, and 1000 are valid\n");
break;
}
val = readl(priv->smba + ISMT_SPGT);
switch (val & ISMT_SPGT_SPD_MASK) {
case ISMT_SPGT_SPD_80K:
bus_speed = 80;
break;
case ISMT_SPGT_SPD_100K:
bus_speed = 100;
break;
case ISMT_SPGT_SPD_400K:
bus_speed = 400;
break;
case ISMT_SPGT_SPD_1M:
bus_speed = 1000;
break;
}
dev_dbg(dev, "SMBus clock is running at %d kHz\n", bus_speed);
}
/**
* ismt_dev_init() - initialize the iSMT data structures
* @priv: iSMT private data
*/
static int 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 ismt_int_init(struct ismt_priv *priv)
{
int err;
/* Try using MSI interrupts */
err = pci_enable_msi(priv->pci_dev);
if (err)
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;
}
return 0;
/* Try using legacy interrupts */
intx:
dev_warn(&priv->pci_dev->dev,
"Unable to use MSI interrupts, falling back to legacy\n");
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 err;
}
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
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->adapter.dev.parent = &pdev->dev;
ACPI_COMPANION_SET(&priv->adapter.dev, ACPI_COMPANION(&pdev->dev));
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");
return -ENODEV;
}
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_err(&pdev->dev, "pci_set_dma_mask fail %p\n",
pdev);
return -ENODEV;
}
}
err = ismt_dev_init(priv);
if (err)
return err;
ismt_hw_init(priv);
err = ismt_int_init(priv);
if (err)
return err;
err = i2c_add_adapter(&priv->adapter);
if (err)
return -ENODEV;
return 0;
}
/**
* ismt_remove() - release driver resources
* @pdev: PCI-Express device
*/
static void ismt_remove(struct pci_dev *pdev)
{
struct ismt_priv *priv = pci_get_drvdata(pdev);
i2c_del_adapter(&priv->adapter);
}
static struct pci_driver ismt_driver = {
.name = "ismt_smbus",
.id_table = ismt_ids,
.probe = ismt_probe,
.remove = ismt_remove,
};
module_pci_driver(ismt_driver);
MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("Bill E. Brown <bill.e.brown@intel.com>");
MODULE_DESCRIPTION("Intel SMBus Message Transport (iSMT) driver");
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