diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-ismt.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-ismt.c | 963 |
1 files changed, 963 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-ismt.c b/drivers/i2c/busses/i2c-ismt.c new file mode 100644 index 00000000000..e9205ee8cf9 --- /dev/null +++ b/drivers/i2c/busses/i2c-ismt.c @@ -0,0 +1,963 @@ +/* + * 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> + +#include <asm-generic/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 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 + 1]; /* 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_SMT0) }, + { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_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 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 = priv->dma_buffer; + + dev_dbg(&priv->pci_dev->dev, "Processing completed descriptor\n"); + __ismt_desc_dump(&priv->pci_dev->dev, desc); + + 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: + 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; + 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); + + /* 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; + priv->dma_buffer[0] = command; + priv->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; + priv->dma_buffer[0] = command; + priv->dma_buffer[1] = data->word & 0xff; + priv->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; + priv->dma_buffer[0] = command; + priv->dma_buffer[1] = data->word & 0xff; + priv->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; + priv->dma_buffer[0] = command; + memcpy(&priv->dma_buffer[1], &data->block[1], dma_size); + } 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(dev, + priv->dma_buffer, + dma_size, + dma_direction); + + if (dma_mapping_error(dev, dma_addr)) { + dev_err(dev, "Error in mapping dma buffer %p\n", + priv->dma_buffer); + return -EIO; + } + + dev_dbg(dev, " dma_addr = 0x%016llX\n", + (unsigned long long)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_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 (unlikely(!ret)) { + 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_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) { + dev_warn(&priv->pci_dev->dev, + "Unable to use MSI interrupts, falling back to legacy\n"); + 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 +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_err(&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 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 = 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@intel.com>"); +MODULE_DESCRIPTION("Intel SMBus Message Transport (iSMT) driver"); |