// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2016 T-Platforms. All Rights Reserved. * * IDT PCIe-switch NTB Linux driver * * Contact Information: * Serge Semin , */ /* * NOTE of the IDT 89HPESx SMBus-slave interface driver * This driver primarily is developed to have an access to EEPROM device of * IDT PCIe-switches. IDT provides a simple SMBus interface to perform IO- * operations from/to EEPROM, which is located at private (so called Master) * SMBus of switches. Using that interface this the driver creates a simple * binary sysfs-file in the device directory: * /sys/bus/i2c/devices/-/eeprom * In case if read-only flag is specified in the dts-node of device desription, * User-space applications won't be able to write to the EEPROM sysfs-node. * Additionally IDT 89HPESx SMBus interface has an ability to write/read * data of device CSRs. This driver exposes debugf-file to perform simple IO * operations using that ability for just basic debug purpose. Particularly * next file is created in the specific debugfs-directory: * /sys/kernel/debug/idt_csr/ * Format of the debugfs-node is: * $ cat /sys/kernel/debug/idt_csr/-/; * : * So reading the content of the file gives current CSR address and it value. * If User-space application wishes to change current CSR address, * it can just write a proper value to the sysfs-file: * $ echo "" > /sys/kernel/debug/idt_csr/-/ * If it wants to change the CSR value as well, the format of the write * operation is: * $ echo ":" > \ * /sys/kernel/debug/idt_csr/-/; * CSR address and value can be any of hexadecimal, decimal or octal format. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define IDT_NAME "89hpesx" #define IDT_89HPESX_DESC "IDT 89HPESx SMBus-slave interface driver" #define IDT_89HPESX_VER "1.0" MODULE_DESCRIPTION(IDT_89HPESX_DESC); MODULE_VERSION(IDT_89HPESX_VER); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("T-platforms"); /* * csr_dbgdir - CSR read/write operations Debugfs directory */ static struct dentry *csr_dbgdir; /* * struct idt_89hpesx_dev - IDT 89HPESx device data structure * @eesize: Size of EEPROM in bytes (calculated from "idt,eecompatible") * @eero: EEPROM Read-only flag * @eeaddr: EEPROM custom address * * @inieecmd: Initial cmd value for EEPROM read/write operations * @inicsrcmd: Initial cmd value for CSR read/write operations * @iniccode: Initialial command code value for IO-operations * * @csr: CSR address to perform read operation * * @smb_write: SMBus write method * @smb_read: SMBus read method * @smb_mtx: SMBus mutex * * @client: i2c client used to perform IO operations * * @ee_file: EEPROM read/write sysfs-file */ struct idt_smb_seq; struct idt_89hpesx_dev { u32 eesize; bool eero; u8 eeaddr; u8 inieecmd; u8 inicsrcmd; u8 iniccode; u16 csr; int (*smb_write)(struct idt_89hpesx_dev *, const struct idt_smb_seq *); int (*smb_read)(struct idt_89hpesx_dev *, struct idt_smb_seq *); struct mutex smb_mtx; struct i2c_client *client; struct bin_attribute *ee_file; struct dentry *csr_dir; }; /* * struct idt_smb_seq - sequence of data to be read/written from/to IDT 89HPESx * @ccode: SMBus command code * @bytecnt: Byte count of operation * @data: Data to by written */ struct idt_smb_seq { u8 ccode; u8 bytecnt; u8 *data; }; /* * struct idt_eeprom_seq - sequence of data to be read/written from/to EEPROM * @cmd: Transaction CMD * @eeaddr: EEPROM custom address * @memaddr: Internal memory address of EEPROM * @data: Data to be written at the memory address */ struct idt_eeprom_seq { u8 cmd; u8 eeaddr; u16 memaddr; u8 data; } __packed; /* * struct idt_csr_seq - sequence of data to be read/written from/to CSR * @cmd: Transaction CMD * @csraddr: Internal IDT device CSR address * @data: Data to be read/written from/to the CSR address */ struct idt_csr_seq { u8 cmd; u16 csraddr; u32 data; } __packed; /* * SMBus command code macros * @CCODE_END: Indicates the end of transaction * @CCODE_START: Indicates the start of transaction * @CCODE_CSR: CSR read/write transaction * @CCODE_EEPROM: EEPROM read/write transaction * @CCODE_BYTE: Supplied data has BYTE length * @CCODE_WORD: Supplied data has WORD length * @CCODE_BLOCK: Supplied data has variable length passed in bytecnt * byte right following CCODE byte */ #define CCODE_END ((u8)0x01) #define CCODE_START ((u8)0x02) #define CCODE_CSR ((u8)0x00) #define CCODE_EEPROM ((u8)0x04) #define CCODE_BYTE ((u8)0x00) #define CCODE_WORD ((u8)0x20) #define CCODE_BLOCK ((u8)0x40) #define CCODE_PEC ((u8)0x80) /* * EEPROM command macros * @EEPROM_OP_WRITE: EEPROM write operation * @EEPROM_OP_READ: EEPROM read operation * @EEPROM_USA: Use specified address of EEPROM * @EEPROM_NAERR: EEPROM device is not ready to respond * @EEPROM_LAERR: EEPROM arbitration loss error * @EEPROM_MSS: EEPROM misplace start & stop bits error * @EEPROM_WR_CNT: Bytes count to perform write operation * @EEPROM_WRRD_CNT: Bytes count to write before reading * @EEPROM_RD_CNT: Bytes count to perform read operation * @EEPROM_DEF_SIZE: Fall back size of EEPROM * @EEPROM_DEF_ADDR: Defatul EEPROM address * @EEPROM_TOUT: Timeout before retry read operation if eeprom is busy */ #define EEPROM_OP_WRITE ((u8)0x00) #define EEPROM_OP_READ ((u8)0x01) #define EEPROM_USA ((u8)0x02) #define EEPROM_NAERR ((u8)0x08) #define EEPROM_LAERR ((u8)0x10) #define EEPROM_MSS ((u8)0x20) #define EEPROM_WR_CNT ((u8)5) #define EEPROM_WRRD_CNT ((u8)4) #define EEPROM_RD_CNT ((u8)5) #define EEPROM_DEF_SIZE ((u16)4096) #define EEPROM_DEF_ADDR ((u8)0x50) #define EEPROM_TOUT (100) /* * CSR command macros * @CSR_DWE: Enable all four bytes of the operation * @CSR_OP_WRITE: CSR write operation * @CSR_OP_READ: CSR read operation * @CSR_RERR: Read operation error * @CSR_WERR: Write operation error * @CSR_WR_CNT: Bytes count to perform write operation * @CSR_WRRD_CNT: Bytes count to write before reading * @CSR_RD_CNT: Bytes count to perform read operation * @CSR_MAX: Maximum CSR address * @CSR_DEF: Default CSR address * @CSR_REAL_ADDR: CSR real unshifted address */ #define CSR_DWE ((u8)0x0F) #define CSR_OP_WRITE ((u8)0x00) #define CSR_OP_READ ((u8)0x10) #define CSR_RERR ((u8)0x40) #define CSR_WERR ((u8)0x80) #define CSR_WR_CNT ((u8)7) #define CSR_WRRD_CNT ((u8)3) #define CSR_RD_CNT ((u8)7) #define CSR_MAX ((u32)0x3FFFF) #define CSR_DEF ((u16)0x0000) #define CSR_REAL_ADDR(val) ((unsigned int)val << 2) /* * IDT 89HPESx basic register * @IDT_VIDDID_CSR: PCIe VID and DID of IDT 89HPESx * @IDT_VID_MASK: Mask of VID */ #define IDT_VIDDID_CSR ((u32)0x0000) #define IDT_VID_MASK ((u32)0xFFFF) /* * IDT 89HPESx can send NACK when new command is sent before previous one * fininshed execution. In this case driver retries operation * certain times. * @RETRY_CNT: Number of retries before giving up and fail * @idt_smb_safe: Generate a retry loop on corresponding SMBus method */ #define RETRY_CNT (128) #define idt_smb_safe(ops, args...) ({ \ int __retry = RETRY_CNT; \ s32 __sts; \ do { \ __sts = i2c_smbus_ ## ops ## _data(args); \ } while (__retry-- && __sts < 0); \ __sts; \ }) /*=========================================================================== * i2c bus level IO-operations *=========================================================================== */ /* * idt_smb_write_byte() - SMBus write method when I2C_SMBUS_BYTE_DATA operation * is only available * @pdev: Pointer to the driver data * @seq: Sequence of data to be written */ static int idt_smb_write_byte(struct idt_89hpesx_dev *pdev, const struct idt_smb_seq *seq) { s32 sts; u8 ccode; int idx; /* Loop over the supplied data sending byte one-by-one */ for (idx = 0; idx < seq->bytecnt; idx++) { /* Collect the command code byte */ ccode = seq->ccode | CCODE_BYTE; if (idx == 0) ccode |= CCODE_START; if (idx == seq->bytecnt - 1) ccode |= CCODE_END; /* Send data to the device */ sts = idt_smb_safe(write_byte, pdev->client, ccode, seq->data[idx]); if (sts != 0) return (int)sts; } return 0; } /* * idt_smb_read_byte() - SMBus read method when I2C_SMBUS_BYTE_DATA operation * is only available * @pdev: Pointer to the driver data * @seq: Buffer to read data to */ static int idt_smb_read_byte(struct idt_89hpesx_dev *pdev, struct idt_smb_seq *seq) { s32 sts; u8 ccode; int idx; /* Loop over the supplied buffer receiving byte one-by-one */ for (idx = 0; idx < seq->bytecnt; idx++) { /* Collect the command code byte */ ccode = seq->ccode | CCODE_BYTE; if (idx == 0) ccode |= CCODE_START; if (idx == seq->bytecnt - 1) ccode |= CCODE_END; /* Read data from the device */ sts = idt_smb_safe(read_byte, pdev->client, ccode); if (sts < 0) return (int)sts; seq->data[idx] = (u8)sts; } return 0; } /* * idt_smb_write_word() - SMBus write method when I2C_SMBUS_BYTE_DATA and * I2C_FUNC_SMBUS_WORD_DATA operations are available * @pdev: Pointer to the driver data * @seq: Sequence of data to be written */ static int idt_smb_write_word(struct idt_89hpesx_dev *pdev, const struct idt_smb_seq *seq) { s32 sts; u8 ccode; int idx, evencnt; /* Calculate the even count of data to send */ evencnt = seq->bytecnt - (seq->bytecnt % 2); /* Loop over the supplied data sending two bytes at a time */ for (idx = 0; idx < evencnt; idx += 2) { /* Collect the command code byte */ ccode = seq->ccode | CCODE_WORD; if (idx == 0) ccode |= CCODE_START; if (idx == evencnt - 2) ccode |= CCODE_END; /* Send word data to the device */ sts = idt_smb_safe(write_word, pdev->client, ccode, *(u16 *)&seq->data[idx]); if (sts != 0) return (int)sts; } /* If there is odd number of bytes then send just one last byte */ if (seq->bytecnt != evencnt) { /* Collect the command code byte */ ccode = seq->ccode | CCODE_BYTE | CCODE_END; if (idx == 0) ccode |= CCODE_START; /* Send byte data to the device */ sts = idt_smb_safe(write_byte, pdev->client, ccode, seq->data[idx]); if (sts != 0) return (int)sts; } return 0; } /* * idt_smb_read_word() - SMBus read method when I2C_SMBUS_BYTE_DATA and * I2C_FUNC_SMBUS_WORD_DATA operations are available * @pdev: Pointer to the driver data * @seq: Buffer to read data to */ static int idt_smb_read_word(struct idt_89hpesx_dev *pdev, struct idt_smb_seq *seq) { s32 sts; u8 ccode; int idx, evencnt; /* Calculate the even count of data to send */ evencnt = seq->bytecnt - (seq->bytecnt % 2); /* Loop over the supplied data reading two bytes at a time */ for (idx = 0; idx < evencnt; idx += 2) { /* Collect the command code byte */ ccode = seq->ccode | CCODE_WORD; if (idx == 0) ccode |= CCODE_START; if (idx == evencnt - 2) ccode |= CCODE_END; /* Read word data from the device */ sts = idt_smb_safe(read_word, pdev->client, ccode); if (sts < 0) return (int)sts; *(u16 *)&seq->data[idx] = (u16)sts; } /* If there is odd number of bytes then receive just one last byte */ if (seq->bytecnt != evencnt) { /* Collect the command code byte */ ccode = seq->ccode | CCODE_BYTE | CCODE_END; if (idx == 0) ccode |= CCODE_START; /* Read last data byte from the device */ sts = idt_smb_safe(read_byte, pdev->client, ccode); if (sts < 0) return (int)sts; seq->data[idx] = (u8)sts; } return 0; } /* * idt_smb_write_block() - SMBus write method when I2C_SMBUS_BLOCK_DATA * operation is available * @pdev: Pointer to the driver data * @seq: Sequence of data to be written */ static int idt_smb_write_block(struct idt_89hpesx_dev *pdev, const struct idt_smb_seq *seq) { u8 ccode; /* Return error if too much data passed to send */ if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX) return -EINVAL; /* Collect the command code byte */ ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END; /* Send block of data to the device */ return idt_smb_safe(write_block, pdev->client, ccode, seq->bytecnt, seq->data); } /* * idt_smb_read_block() - SMBus read method when I2C_SMBUS_BLOCK_DATA * operation is available * @pdev: Pointer to the driver data * @seq: Buffer to read data to */ static int idt_smb_read_block(struct idt_89hpesx_dev *pdev, struct idt_smb_seq *seq) { s32 sts; u8 ccode; /* Return error if too much data passed to send */ if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX) return -EINVAL; /* Collect the command code byte */ ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END; /* Read block of data from the device */ sts = idt_smb_safe(read_block, pdev->client, ccode, seq->data); if (sts != seq->bytecnt) return (sts < 0 ? sts : -ENODATA); return 0; } /* * idt_smb_write_i2c_block() - SMBus write method when I2C_SMBUS_I2C_BLOCK_DATA * operation is available * @pdev: Pointer to the driver data * @seq: Sequence of data to be written * * NOTE It's usual SMBus write block operation, except the actual data length is * sent as first byte of data */ static int idt_smb_write_i2c_block(struct idt_89hpesx_dev *pdev, const struct idt_smb_seq *seq) { u8 ccode, buf[I2C_SMBUS_BLOCK_MAX + 1]; /* Return error if too much data passed to send */ if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX) return -EINVAL; /* Collect the data to send. Length byte must be added prior the data */ buf[0] = seq->bytecnt; memcpy(&buf[1], seq->data, seq->bytecnt); /* Collect the command code byte */ ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END; /* Send length and block of data to the device */ return idt_smb_safe(write_i2c_block, pdev->client, ccode, seq->bytecnt + 1, buf); } /* * idt_smb_read_i2c_block() - SMBus read method when I2C_SMBUS_I2C_BLOCK_DATA * operation is available * @pdev: Pointer to the driver data * @seq: Buffer to read data to * * NOTE It's usual SMBus read block operation, except the actual data length is * retrieved as first byte of data */ static int idt_smb_read_i2c_block(struct idt_89hpesx_dev *pdev, struct idt_smb_seq *seq) { u8 ccode, buf[I2C_SMBUS_BLOCK_MAX + 1]; s32 sts; /* Return error if too much data passed to send */ if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX) return -EINVAL; /* Collect the command code byte */ ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END; /* Read length and block of data from the device */ sts = idt_smb_safe(read_i2c_block, pdev->client, ccode, seq->bytecnt + 1, buf); if (sts != seq->bytecnt + 1) return (sts < 0 ? sts : -ENODATA); if (buf[0] != seq->bytecnt) return -ENODATA; /* Copy retrieved data to the output data buffer */ memcpy(seq->data, &buf[1], seq->bytecnt); return 0; } /*=========================================================================== * EEPROM IO-operations *=========================================================================== */ /* * idt_eeprom_read_byte() - read just one byte from EEPROM * @pdev: Pointer to the driver data * @memaddr: Start EEPROM memory address * @data: Data to be written to EEPROM */ static int idt_eeprom_read_byte(struct idt_89hpesx_dev *pdev, u16 memaddr, u8 *data) { struct device *dev = &pdev->client->dev; struct idt_eeprom_seq eeseq; struct idt_smb_seq smbseq; int ret, retry; /* Initialize SMBus sequence fields */ smbseq.ccode = pdev->iniccode | CCODE_EEPROM; smbseq.data = (u8 *)&eeseq; /* * Sometimes EEPROM may respond with NACK if it's busy with previous * operation, so we need to perform a few attempts of read cycle */ retry = RETRY_CNT; do { /* Send EEPROM memory address to read data from */ smbseq.bytecnt = EEPROM_WRRD_CNT; eeseq.cmd = pdev->inieecmd | EEPROM_OP_READ; eeseq.eeaddr = pdev->eeaddr; eeseq.memaddr = cpu_to_le16(memaddr); ret = pdev->smb_write(pdev, &smbseq); if (ret != 0) { dev_err(dev, "Failed to init eeprom addr 0x%02hhx", memaddr); break; } /* Perform read operation */ smbseq.bytecnt = EEPROM_RD_CNT; ret = pdev->smb_read(pdev, &smbseq); if (ret != 0) { dev_err(dev, "Failed to read eeprom data 0x%02hhx", memaddr); break; } /* Restart read operation if the device is busy */ if (retry && (eeseq.cmd & EEPROM_NAERR)) { dev_dbg(dev, "EEPROM busy, retry reading after %d ms", EEPROM_TOUT); msleep(EEPROM_TOUT); continue; } /* Check whether IDT successfully read data from EEPROM */ if (eeseq.cmd & (EEPROM_NAERR | EEPROM_LAERR | EEPROM_MSS)) { dev_err(dev, "Communication with eeprom failed, cmd 0x%hhx", eeseq.cmd); ret = -EREMOTEIO; break; } /* Save retrieved data and exit the loop */ *data = eeseq.data; break; } while (retry--); /* Return the status of operation */ return ret; } /* * idt_eeprom_write() - EEPROM write operation * @pdev: Pointer to the driver data * @memaddr: Start EEPROM memory address * @len: Length of data to be written * @data: Data to be written to EEPROM */ static int idt_eeprom_write(struct idt_89hpesx_dev *pdev, u16 memaddr, u16 len, const u8 *data) { struct device *dev = &pdev->client->dev; struct idt_eeprom_seq eeseq; struct idt_smb_seq smbseq; int ret; u16 idx; /* Initialize SMBus sequence fields */ smbseq.ccode = pdev->iniccode | CCODE_EEPROM; smbseq.data = (u8 *)&eeseq; /* Send data byte-by-byte, checking if it is successfully written */ for (idx = 0; idx < len; idx++, memaddr++) { /* Lock IDT SMBus device */ mutex_lock(&pdev->smb_mtx); /* Perform write operation */ smbseq.bytecnt = EEPROM_WR_CNT; eeseq.cmd = pdev->inieecmd | EEPROM_OP_WRITE; eeseq.eeaddr = pdev->eeaddr; eeseq.memaddr = cpu_to_le16(memaddr); eeseq.data = data[idx]; ret = pdev->smb_write(pdev, &smbseq); if (ret != 0) { dev_err(dev, "Failed to write 0x%04hx:0x%02hhx to eeprom", memaddr, data[idx]); goto err_mutex_unlock; } /* * Check whether the data is successfully written by reading * from the same EEPROM memory address. */ eeseq.data = ~data[idx]; ret = idt_eeprom_read_byte(pdev, memaddr, &eeseq.data); if (ret != 0) goto err_mutex_unlock; /* Check whether the read byte is the same as written one */ if (eeseq.data != data[idx]) { dev_err(dev, "Values don't match 0x%02hhx != 0x%02hhx", eeseq.data, data[idx]); ret = -EREMOTEIO; goto err_mutex_unlock; } /* Unlock IDT SMBus device */ err_mutex_unlock: mutex_unlock(&pdev->smb_mtx); if (ret != 0) return ret; } return 0; } /* * idt_eeprom_read() - EEPROM read operation * @pdev: Pointer to the driver data * @memaddr: Start EEPROM memory address * @len: Length of data to read * @buf: Buffer to read data to */ static int idt_eeprom_read(struct idt_89hpesx_dev *pdev, u16 memaddr, u16 len, u8 *buf) { int ret; u16 idx; /* Read data byte-by-byte, retrying if it wasn't successful */ for (idx = 0; idx < len; idx++, memaddr++) { /* Lock IDT SMBus device */ mutex_lock(&pdev->smb_mtx); /* Just read the byte to the buffer */ ret = idt_eeprom_read_byte(pdev, memaddr, &buf[idx]); /* Unlock IDT SMBus device */ mutex_unlock(&pdev->smb_mtx); /* Return error if read operation failed */ if (ret != 0) return ret; } return 0; } /*=========================================================================== * CSR IO-operations *=========================================================================== */ /* * idt_csr_write() - CSR write operation * @pdev: Pointer to the driver data * @csraddr: CSR address (with no two LS bits) * @data: Data to be written to CSR */ static int idt_csr_write(struct idt_89hpesx_dev *pdev, u16 csraddr, const u32 data) { struct device *dev = &pdev->client->dev; struct idt_csr_seq csrseq; struct idt_smb_seq smbseq; int ret; /* Initialize SMBus sequence fields */ smbseq.ccode = pdev->iniccode | CCODE_CSR; smbseq.data = (u8 *)&csrseq; /* Lock IDT SMBus device */ mutex_lock(&pdev->smb_mtx); /* Perform write operation */ smbseq.bytecnt = CSR_WR_CNT; csrseq.cmd = pdev->inicsrcmd | CSR_OP_WRITE; csrseq.csraddr = cpu_to_le16(csraddr); csrseq.data = cpu_to_le32(data); ret = pdev->smb_write(pdev, &smbseq); if (ret != 0) { dev_err(dev, "Failed to write 0x%04x: 0x%04x to csr", CSR_REAL_ADDR(csraddr), data); goto err_mutex_unlock; } /* Send CSR address to read data from */ smbseq.bytecnt = CSR_WRRD_CNT; csrseq.cmd = pdev->inicsrcmd | CSR_OP_READ; ret = pdev->smb_write(pdev, &smbseq); if (ret != 0) { dev_err(dev, "Failed to init csr address 0x%04x", CSR_REAL_ADDR(csraddr)); goto err_mutex_unlock; } /* Perform read operation */ smbseq.bytecnt = CSR_RD_CNT; ret = pdev->smb_read(pdev, &smbseq); if (ret != 0) { dev_err(dev, "Failed to read csr 0x%04x", CSR_REAL_ADDR(csraddr)); goto err_mutex_unlock; } /* Check whether IDT successfully retrieved CSR data */ if (csrseq.cmd & (CSR_RERR | CSR_WERR)) { dev_err(dev, "IDT failed to perform CSR r/w"); ret = -EREMOTEIO; goto err_mutex_unlock; } /* Unlock IDT SMBus device */ err_mutex_unlock: mutex_unlock(&pdev->smb_mtx); return ret; } /* * idt_csr_read() - CSR read operation * @pdev: Pointer to the driver data * @csraddr: CSR address (with no two LS bits) * @data: Data to be written to CSR */ static int idt_csr_read(struct idt_89hpesx_dev *pdev, u16 csraddr, u32 *data) { struct device *dev = &pdev->client->dev; struct idt_csr_seq csrseq; struct idt_smb_seq smbseq; int ret; /* Initialize SMBus sequence fields */ smbseq.ccode = pdev->iniccode | CCODE_CSR; smbseq.data = (u8 *)&csrseq; /* Lock IDT SMBus device */ mutex_lock(&pdev->smb_mtx); /* Send CSR register address before reading it */ smbseq.bytecnt = CSR_WRRD_CNT; csrseq.cmd = pdev->inicsrcmd | CSR_OP_READ; csrseq.csraddr = cpu_to_le16(csraddr); ret = pdev->smb_write(pdev, &smbseq); if (ret != 0) { dev_err(dev, "Failed to init csr address 0x%04x", CSR_REAL_ADDR(csraddr)); goto err_mutex_unlock; } /* Perform read operation */ smbseq.bytecnt = CSR_RD_CNT; ret = pdev->smb_read(pdev, &smbseq); if (ret != 0) { dev_err(dev, "Failed to read csr 0x%04hx", CSR_REAL_ADDR(csraddr)); goto err_mutex_unlock; } /* Check whether IDT successfully retrieved CSR data */ if (csrseq.cmd & (CSR_RERR | CSR_WERR)) { dev_err(dev, "IDT failed to perform CSR r/w"); ret = -EREMOTEIO; goto err_mutex_unlock; } /* Save data retrieved from IDT */ *data = le32_to_cpu(csrseq.data); /* Unlock IDT SMBus device */ err_mutex_unlock: mutex_unlock(&pdev->smb_mtx); return ret; } /*=========================================================================== * Sysfs/debugfs-nodes IO-operations *=========================================================================== */ /* * eeprom_write() - EEPROM sysfs-node write callback * @filep: Pointer to the file system node * @kobj: Pointer to the kernel object related to the sysfs-node * @attr: Attributes of the file * @buf: Buffer to write data to * @off: Offset at which data should be written to * @count: Number of bytes to write */ static ssize_t eeprom_write(struct file *filp, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) { struct idt_89hpesx_dev *pdev; int ret; /* Retrieve driver data */ pdev = dev_get_drvdata(kobj_to_dev(kobj)); /* Perform EEPROM write operation */ ret = idt_eeprom_write(pdev, (u16)off, (u16)count, (u8 *)buf); return (ret != 0 ? ret : count); } /* * eeprom_read() - EEPROM sysfs-node read callback * @filep: Pointer to the file system node * @kobj: Pointer to the kernel object related to the sysfs-node * @attr: Attributes of the file * @buf: Buffer to write data to * @off: Offset at which data should be written to * @count: Number of bytes to write */ static ssize_t eeprom_read(struct file *filp, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) { struct idt_89hpesx_dev *pdev; int ret; /* Retrieve driver data */ pdev = dev_get_drvdata(kobj_to_dev(kobj)); /* Perform EEPROM read operation */ ret = idt_eeprom_read(pdev, (u16)off, (u16)count, (u8 *)buf); return (ret != 0 ? ret : count); } /* * idt_dbgfs_csr_write() - CSR debugfs-node write callback * @filep: Pointer to the file system file descriptor * @buf: Buffer to read data from * @count: Size of the buffer * @offp: Offset within the file * * It accepts either "0x:0x" for saving register address * and writing value to specified DWORD register or "0x" for * just saving register address in order to perform next read operation. * * WARNING No spaces are allowed. Incoming string must be strictly formated as: * ":". Register address must be aligned within 4 bytes * (one DWORD). */ static ssize_t idt_dbgfs_csr_write(struct file *filep, const char __user *ubuf, size_t count, loff_t *offp) { struct idt_89hpesx_dev *pdev = filep->private_data; char *colon_ch, *csraddr_str, *csrval_str; int ret, csraddr_len; u32 csraddr, csrval; char *buf; /* Copy data from User-space */ buf = kmalloc(count + 1, GFP_KERNEL); if (!buf) return -ENOMEM; ret = simple_write_to_buffer(buf, count, offp, ubuf, count); if (ret < 0) goto free_buf; buf[count] = 0; /* Find position of colon in the buffer */ colon_ch = strnchr(buf, count, ':'); /* * If there is colon passed then new CSR value should be parsed as * well, so allocate buffer for CSR address substring. * If no colon is found, then string must have just one number with * no new CSR value */ if (colon_ch != NULL) { csraddr_len = colon_ch - buf; csraddr_str = kmalloc(csraddr_len + 1, GFP_KERNEL); if (csraddr_str == NULL) { ret = -ENOMEM; goto free_buf; } /* Copy the register address to the substring buffer */ strncpy(csraddr_str, buf, csraddr_len); csraddr_str[csraddr_len] = '\0'; /* Register value must follow the colon */ csrval_str = colon_ch + 1; } else /* if (str_colon == NULL) */ { csraddr_str = (char *)buf; /* Just to shut warning up */ csraddr_len = strnlen(csraddr_str, count); csrval_str = NULL; } /* Convert CSR address to u32 value */ ret = kstrtou32(csraddr_str, 0, &csraddr); if (ret != 0) goto free_csraddr_str; /* Check whether passed register address is valid */ if (csraddr > CSR_MAX || !IS_ALIGNED(csraddr, SZ_4)) { ret = -EINVAL; goto free_csraddr_str; } /* Shift register address to the right so to have u16 address */ pdev->csr = (csraddr >> 2); /* Parse new CSR value and send it to IDT, if colon has been found */ if (colon_ch != NULL) { ret = kstrtou32(csrval_str, 0, &csrval); if (ret != 0) goto free_csraddr_str; ret = idt_csr_write(pdev, pdev->csr, csrval); if (ret != 0) goto free_csraddr_str; } /* Free memory only if colon has been found */ free_csraddr_str: if (colon_ch != NULL) kfree(csraddr_str); /* Free buffer allocated for data retrieved from User-space */ free_buf: kfree(buf); return (ret != 0 ? ret : count); } /* * idt_dbgfs_csr_read() - CSR debugfs-node read callback * @filep: Pointer to the file system file descriptor * @buf: Buffer to write data to * @count: Size of the buffer * @offp: Offset within the file * * It just prints the pair "0x:0x" to passed buffer. */ #define CSRBUF_SIZE ((size_t)32) static ssize_t idt_dbgfs_csr_read(struct file *filep, char __user *ubuf, size_t count, loff_t *offp) { struct idt_89hpesx_dev *pdev = filep->private_data; u32 csraddr, csrval; char buf[CSRBUF_SIZE]; int ret, size; /* Perform CSR read operation */ ret = idt_csr_read(pdev, pdev->csr, &csrval); if (ret != 0) return ret; /* Shift register address to the left so to have real address */ csraddr = ((u32)pdev->csr << 2); /* Print the "0x:0x" to buffer */ size = snprintf(buf, CSRBUF_SIZE, "0x%05x:0x%08x\n", (unsigned int)csraddr, (unsigned int)csrval); /* Copy data to User-space */ return simple_read_from_buffer(ubuf, count, offp, buf, size); } /* * eeprom_attribute - EEPROM sysfs-node attributes * * NOTE Size will be changed in compliance with OF node. EEPROM attribute will * be read-only as well if the corresponding flag is specified in OF node. */ static BIN_ATTR_RW(eeprom, EEPROM_DEF_SIZE); /* * csr_dbgfs_ops - CSR debugfs-node read/write operations */ static const struct file_operations csr_dbgfs_ops = { .owner = THIS_MODULE, .open = simple_open, .write = idt_dbgfs_csr_write, .read = idt_dbgfs_csr_read }; /*=========================================================================== * Driver init/deinit methods *=========================================================================== */ /* * idt_set_defval() - disable EEPROM access by default * @pdev: Pointer to the driver data */ static void idt_set_defval(struct idt_89hpesx_dev *pdev) { /* If OF info is missing then use next values */ pdev->eesize = 0; pdev->eero = true; pdev->inieecmd = 0; pdev->eeaddr = 0; } static const struct i2c_device_id ee_ids[]; /* * idt_ee_match_id() - check whether the node belongs to compatible EEPROMs */ static const struct i2c_device_id *idt_ee_match_id(struct fwnode_handle *fwnode) { const struct i2c_device_id *id = ee_ids; const char *compatible, *p; char devname[I2C_NAME_SIZE]; int ret; ret = fwnode_property_read_string(fwnode, "compatible", &compatible); if (ret) return NULL; p = strchr(compatible, ','); strlcpy(devname, p ? p + 1 : compatible, sizeof(devname)); /* Search through the device name */ while (id->name[0]) { if (strcmp(devname, id->name) == 0) return id; id++; } return NULL; } /* * idt_get_fw_data() - get IDT i2c-device parameters from device tree * @pdev: Pointer to the driver data */ static void idt_get_fw_data(struct idt_89hpesx_dev *pdev) { struct device *dev = &pdev->client->dev; struct fwnode_handle *fwnode; const struct i2c_device_id *ee_id = NULL; u32 eeprom_addr; int ret; device_for_each_child_node(dev, fwnode) { ee_id = idt_ee_match_id(fwnode); if (ee_id) break; dev_warn(dev, "Skip unsupported EEPROM device %pfw\n", fwnode); } /* If there is no fwnode EEPROM device, then set zero size */ if (!ee_id) { dev_warn(dev, "No fwnode, EEPROM access disabled"); idt_set_defval(pdev); return; } /* Retrieve EEPROM size */ pdev->eesize = (u32)ee_id->driver_data; /* Get custom EEPROM address from 'reg' attribute */ ret = fwnode_property_read_u32(fwnode, "reg", &eeprom_addr); if (ret || (eeprom_addr == 0)) { dev_warn(dev, "No EEPROM reg found, use default address 0x%x", EEPROM_DEF_ADDR); pdev->inieecmd = 0; pdev->eeaddr = EEPROM_DEF_ADDR << 1; } else { pdev->inieecmd = EEPROM_USA; pdev->eeaddr = eeprom_addr << 1; } /* Check EEPROM 'read-only' flag */ if (fwnode_property_read_bool(fwnode, "read-only")) pdev->eero = true; else /* if (!fwnode_property_read_bool(node, "read-only")) */ pdev->eero = false; fwnode_handle_put(fwnode); dev_info(dev, "EEPROM of %d bytes found by 0x%x", pdev->eesize, pdev->eeaddr); } /* * idt_create_pdev() - create and init data structure of the driver * @client: i2c client of IDT PCIe-switch device */ static struct idt_89hpesx_dev *idt_create_pdev(struct i2c_client *client) { struct idt_89hpesx_dev *pdev; /* Allocate memory for driver data */ pdev = devm_kmalloc(&client->dev, sizeof(struct idt_89hpesx_dev), GFP_KERNEL); if (pdev == NULL) return ERR_PTR(-ENOMEM); /* Initialize basic fields of the data */ pdev->client = client; i2c_set_clientdata(client, pdev); /* Read firmware nodes information */ idt_get_fw_data(pdev); /* Initialize basic CSR CMD field - use full DWORD-sized r/w ops */ pdev->inicsrcmd = CSR_DWE; pdev->csr = CSR_DEF; /* Enable Packet Error Checking if it's supported by adapter */ if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_PEC)) { pdev->iniccode = CCODE_PEC; client->flags |= I2C_CLIENT_PEC; } else /* PEC is unsupported */ { pdev->iniccode = 0; } return pdev; } /* * idt_free_pdev() - free data structure of the driver * @pdev: Pointer to the driver data */ static void idt_free_pdev(struct idt_89hpesx_dev *pdev) { /* Clear driver data from device private field */ i2c_set_clientdata(pdev->client, NULL); } /* * idt_set_smbus_ops() - set supported SMBus operations * @pdev: Pointer to the driver data * Return status of smbus check operations */ static int idt_set_smbus_ops(struct idt_89hpesx_dev *pdev) { struct i2c_adapter *adapter = pdev->client->adapter; struct device *dev = &pdev->client->dev; /* Check i2c adapter read functionality */ if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BLOCK_DATA)) { pdev->smb_read = idt_smb_read_block; dev_dbg(dev, "SMBus block-read op chosen"); } else if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { pdev->smb_read = idt_smb_read_i2c_block; dev_dbg(dev, "SMBus i2c-block-read op chosen"); } else if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_WORD_DATA) && i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA)) { pdev->smb_read = idt_smb_read_word; dev_warn(dev, "Use slow word/byte SMBus read ops"); } else if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA)) { pdev->smb_read = idt_smb_read_byte; dev_warn(dev, "Use slow byte SMBus read op"); } else /* no supported smbus read operations */ { dev_err(dev, "No supported SMBus read op"); return -EPFNOSUPPORT; } /* Check i2c adapter write functionality */ if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)) { pdev->smb_write = idt_smb_write_block; dev_dbg(dev, "SMBus block-write op chosen"); } else if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)) { pdev->smb_write = idt_smb_write_i2c_block; dev_dbg(dev, "SMBus i2c-block-write op chosen"); } else if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_WORD_DATA) && i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) { pdev->smb_write = idt_smb_write_word; dev_warn(dev, "Use slow word/byte SMBus write op"); } else if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) { pdev->smb_write = idt_smb_write_byte; dev_warn(dev, "Use slow byte SMBus write op"); } else /* no supported smbus write operations */ { dev_err(dev, "No supported SMBus write op"); return -EPFNOSUPPORT; } /* Initialize IDT SMBus slave interface mutex */ mutex_init(&pdev->smb_mtx); return 0; } /* * idt_check_dev() - check whether it's really IDT 89HPESx device * @pdev: Pointer to the driver data * Return status of i2c adapter check operation */ static int idt_check_dev(struct idt_89hpesx_dev *pdev) { struct device *dev = &pdev->client->dev; u32 viddid; int ret; /* Read VID and DID directly from IDT memory space */ ret = idt_csr_read(pdev, IDT_VIDDID_CSR, &viddid); if (ret != 0) { dev_err(dev, "Failed to read VID/DID"); return ret; } /* Check whether it's IDT device */ if ((viddid & IDT_VID_MASK) != PCI_VENDOR_ID_IDT) { dev_err(dev, "Got unsupported VID/DID: 0x%08x", viddid); return -ENODEV; } dev_info(dev, "Found IDT 89HPES device VID:0x%04x, DID:0x%04x", (viddid & IDT_VID_MASK), (viddid >> 16)); return 0; } /* * idt_create_sysfs_files() - create sysfs attribute files * @pdev: Pointer to the driver data * Return status of operation */ static int idt_create_sysfs_files(struct idt_89hpesx_dev *pdev) { struct device *dev = &pdev->client->dev; int ret; /* Don't do anything if EEPROM isn't accessible */ if (pdev->eesize == 0) { dev_dbg(dev, "Skip creating sysfs-files"); return 0; } /* Allocate memory for attribute file */ pdev->ee_file = devm_kmalloc(dev, sizeof(*pdev->ee_file), GFP_KERNEL); if (!pdev->ee_file) return -ENOMEM; /* Copy the declared EEPROM attr structure to change some of fields */ memcpy(pdev->ee_file, &bin_attr_eeprom, sizeof(*pdev->ee_file)); /* In case of read-only EEPROM get rid of write ability */ if (pdev->eero) { pdev->ee_file->attr.mode &= ~0200; pdev->ee_file->write = NULL; } /* Create EEPROM sysfs file */ pdev->ee_file->size = pdev->eesize; ret = sysfs_create_bin_file(&dev->kobj, pdev->ee_file); if (ret != 0) { dev_err(dev, "Failed to create EEPROM sysfs-node"); return ret; } return 0; } /* * idt_remove_sysfs_files() - remove sysfs attribute files * @pdev: Pointer to the driver data */ static void idt_remove_sysfs_files(struct idt_89hpesx_dev *pdev) { struct device *dev = &pdev->client->dev; /* Don't do anything if EEPROM wasn't accessible */ if (pdev->eesize == 0) return; /* Remove EEPROM sysfs file */ sysfs_remove_bin_file(&dev->kobj, pdev->ee_file); } /* * idt_create_dbgfs_files() - create debugfs files * @pdev: Pointer to the driver data */ #define CSRNAME_LEN ((size_t)32) static void idt_create_dbgfs_files(struct idt_89hpesx_dev *pdev) { struct i2c_client *cli = pdev->client; char fname[CSRNAME_LEN]; /* Create Debugfs directory for CSR file */ snprintf(fname, CSRNAME_LEN, "%d-%04hx", cli->adapter->nr, cli->addr); pdev->csr_dir = debugfs_create_dir(fname, csr_dbgdir); /* Create Debugfs file for CSR read/write operations */ debugfs_create_file(cli->name, 0600, pdev->csr_dir, pdev, &csr_dbgfs_ops); } /* * idt_remove_dbgfs_files() - remove debugfs files * @pdev: Pointer to the driver data */ static void idt_remove_dbgfs_files(struct idt_89hpesx_dev *pdev) { /* Remove CSR directory and it sysfs-node */ debugfs_remove_recursive(pdev->csr_dir); } /* * idt_probe() - IDT 89HPESx driver probe() callback method */ static int idt_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct idt_89hpesx_dev *pdev; int ret; /* Create driver data */ pdev = idt_create_pdev(client); if (IS_ERR(pdev)) return PTR_ERR(pdev); /* Set SMBus operations */ ret = idt_set_smbus_ops(pdev); if (ret != 0) goto err_free_pdev; /* Check whether it is truly IDT 89HPESx device */ ret = idt_check_dev(pdev); if (ret != 0) goto err_free_pdev; /* Create sysfs files */ ret = idt_create_sysfs_files(pdev); if (ret != 0) goto err_free_pdev; /* Create debugfs files */ idt_create_dbgfs_files(pdev); return 0; err_free_pdev: idt_free_pdev(pdev); return ret; } /* * idt_remove() - IDT 89HPESx driver remove() callback method */ static int idt_remove(struct i2c_client *client) { struct idt_89hpesx_dev *pdev = i2c_get_clientdata(client); /* Remove debugfs files first */ idt_remove_dbgfs_files(pdev); /* Remove sysfs files */ idt_remove_sysfs_files(pdev); /* Discard driver data structure */ idt_free_pdev(pdev); return 0; } /* * ee_ids - array of supported EEPROMs */ static const struct i2c_device_id ee_ids[] = { { "24c32", 4096}, { "24c64", 8192}, { "24c128", 16384}, { "24c256", 32768}, { "24c512", 65536}, {} }; MODULE_DEVICE_TABLE(i2c, ee_ids); /* * idt_ids - supported IDT 89HPESx devices */ static const struct i2c_device_id idt_ids[] = { { "89hpes8nt2", 0 }, { "89hpes12nt3", 0 }, { "89hpes24nt6ag2", 0 }, { "89hpes32nt8ag2", 0 }, { "89hpes32nt8bg2", 0 }, { "89hpes12nt12g2", 0 }, { "89hpes16nt16g2", 0 }, { "89hpes24nt24g2", 0 }, { "89hpes32nt24ag2", 0 }, { "89hpes32nt24bg2", 0 }, { "89hpes12n3", 0 }, { "89hpes12n3a", 0 }, { "89hpes24n3", 0 }, { "89hpes24n3a", 0 }, { "89hpes32h8", 0 }, { "89hpes32h8g2", 0 }, { "89hpes48h12", 0 }, { "89hpes48h12g2", 0 }, { "89hpes48h12ag2", 0 }, { "89hpes16h16", 0 }, { "89hpes22h16", 0 }, { "89hpes22h16g2", 0 }, { "89hpes34h16", 0 }, { "89hpes34h16g2", 0 }, { "89hpes64h16", 0 }, { "89hpes64h16g2", 0 }, { "89hpes64h16ag2", 0 }, /* { "89hpes3t3", 0 }, // No SMBus-slave iface */ { "89hpes12t3g2", 0 }, { "89hpes24t3g2", 0 }, /* { "89hpes4t4", 0 }, // No SMBus-slave iface */ { "89hpes16t4", 0 }, { "89hpes4t4g2", 0 }, { "89hpes10t4g2", 0 }, { "89hpes16t4g2", 0 }, { "89hpes16t4ag2", 0 }, { "89hpes5t5", 0 }, { "89hpes6t5", 0 }, { "89hpes8t5", 0 }, { "89hpes8t5a", 0 }, { "89hpes24t6", 0 }, { "89hpes6t6g2", 0 }, { "89hpes24t6g2", 0 }, { "89hpes16t7", 0 }, { "89hpes32t8", 0 }, { "89hpes32t8g2", 0 }, { "89hpes48t12", 0 }, { "89hpes48t12g2", 0 }, { /* END OF LIST */ } }; MODULE_DEVICE_TABLE(i2c, idt_ids); static const struct of_device_id idt_of_match[] = { { .compatible = "idt,89hpes8nt2", }, { .compatible = "idt,89hpes12nt3", }, { .compatible = "idt,89hpes24nt6ag2", }, { .compatible = "idt,89hpes32nt8ag2", }, { .compatible = "idt,89hpes32nt8bg2", }, { .compatible = "idt,89hpes12nt12g2", }, { .compatible = "idt,89hpes16nt16g2", }, { .compatible = "idt,89hpes24nt24g2", }, { .compatible = "idt,89hpes32nt24ag2", }, { .compatible = "idt,89hpes32nt24bg2", }, { .compatible = "idt,89hpes12n3", }, { .compatible = "idt,89hpes12n3a", }, { .compatible = "idt,89hpes24n3", }, { .compatible = "idt,89hpes24n3a", }, { .compatible = "idt,89hpes32h8", }, { .compatible = "idt,89hpes32h8g2", }, { .compatible = "idt,89hpes48h12", }, { .compatible = "idt,89hpes48h12g2", }, { .compatible = "idt,89hpes48h12ag2", }, { .compatible = "idt,89hpes16h16", }, { .compatible = "idt,89hpes22h16", }, { .compatible = "idt,89hpes22h16g2", }, { .compatible = "idt,89hpes34h16", }, { .compatible = "idt,89hpes34h16g2", }, { .compatible = "idt,89hpes64h16", }, { .compatible = "idt,89hpes64h16g2", }, { .compatible = "idt,89hpes64h16ag2", }, { .compatible = "idt,89hpes12t3g2", }, { .compatible = "idt,89hpes24t3g2", }, { .compatible = "idt,89hpes16t4", }, { .compatible = "idt,89hpes4t4g2", }, { .compatible = "idt,89hpes10t4g2", }, { .compatible = "idt,89hpes16t4g2", }, { .compatible = "idt,89hpes16t4ag2", }, { .compatible = "idt,89hpes5t5", }, { .compatible = "idt,89hpes6t5", }, { .compatible = "idt,89hpes8t5", }, { .compatible = "idt,89hpes8t5a", }, { .compatible = "idt,89hpes24t6", }, { .compatible = "idt,89hpes6t6g2", }, { .compatible = "idt,89hpes24t6g2", }, { .compatible = "idt,89hpes16t7", }, { .compatible = "idt,89hpes32t8", }, { .compatible = "idt,89hpes32t8g2", }, { .compatible = "idt,89hpes48t12", }, { .compatible = "idt,89hpes48t12g2", }, { }, }; MODULE_DEVICE_TABLE(of, idt_of_match); /* * idt_driver - IDT 89HPESx driver structure */ static struct i2c_driver idt_driver = { .driver = { .name = IDT_NAME, .of_match_table = idt_of_match, }, .probe = idt_probe, .remove = idt_remove, .id_table = idt_ids, }; /* * idt_init() - IDT 89HPESx driver init() callback method */ static int __init idt_init(void) { /* Create Debugfs directory first */ if (debugfs_initialized()) csr_dbgdir = debugfs_create_dir("idt_csr", NULL); /* Add new i2c-device driver */ return i2c_add_driver(&idt_driver); } module_init(idt_init); /* * idt_exit() - IDT 89HPESx driver exit() callback method */ static void __exit idt_exit(void) { /* Discard debugfs directory and all files if any */ debugfs_remove_recursive(csr_dbgdir); /* Unregister i2c-device driver */ i2c_del_driver(&idt_driver); } module_exit(idt_exit);