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Subject[PATCH v4 1/2] eeprom: Add IDT 89HPESx EEPROM/CSR driver
Date
  This driver provides an access to EEPROM of IDT PCIe-switches. IDT PCIe-
switches expose a simple SMBus interface to perform IO-operations from/to
EEPROM, which is located at private (so called Master) SMBus. The driver
creates a simple binary sysfs-file to have an access to the EEPROM using
the SMBus-slave interface in the i2c-device susfs-directory:
/sys/bus/i2c/devices/<bus>-<devaddr>/eeprom
In case if read-only flag is specified at dts-node of the device, User-space
applications won't be able to write to the EEPROM sysfs-node.

Additionally IDT 89HPESx SMBus interface has an ability to read/write
values of device CSRs. This driver exposes debugfs-file to perform simple
IO-operations using that ability for just basic debug purpose. Particularly
the next file is created in the specific debugfs-directory:
/sys/kernel/debug/idt_csr/
Format of the debugfs-file value is:
$ cat /sys/kernel/debug/idt_csr/<bus>-<devaddr>/<devname>;
<CSR address>:<CSR value>
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 "<CSR address>" >
/sys/kernel/debug/idt_csr/<bus>-<devaddr>/<devname>
If it wants to change the CSR value as well, the format of the write
operation is:
$ echo "<CSR address>:<CSR value>" > \
/sys/kernel/debug/idt_csr/<bus>-<devaddr>/<devname>;
CSR address and value can be any of hexadecimal, decimal or octal format.

Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
---
drivers/misc/eeprom/Kconfig | 10 +
drivers/misc/eeprom/Makefile | 1 +
drivers/misc/eeprom/idt_89hpesx.c | 1634 +++++++++++++++++++++++++++++++++++++
3 files changed, 1645 insertions(+)
create mode 100644 drivers/misc/eeprom/idt_89hpesx.c

diff --git a/drivers/misc/eeprom/Kconfig b/drivers/misc/eeprom/Kconfig
index c4e41c2..de58762 100644
--- a/drivers/misc/eeprom/Kconfig
+++ b/drivers/misc/eeprom/Kconfig
@@ -100,4 +100,14 @@ config EEPROM_DIGSY_MTC_CFG

If unsure, say N.

+config EEPROM_IDT_89HPESX
+ tristate "IDT 89HPESx PCIe-swtiches EEPROM / CSR support"
+ depends on I2C && SYSFS
+ help
+ Enable this driver to get read/write access to EEPROM / CSRs
+ over IDT PCIe-swtich i2c-slave interface.
+
+ This driver can also be built as a module. If so, the module
+ will be called idt_89hpesx.
+
endmenu
diff --git a/drivers/misc/eeprom/Makefile b/drivers/misc/eeprom/Makefile
index fc1e81d..90a5262 100644
--- a/drivers/misc/eeprom/Makefile
+++ b/drivers/misc/eeprom/Makefile
@@ -5,3 +5,4 @@ obj-$(CONFIG_EEPROM_MAX6875) += max6875.o
obj-$(CONFIG_EEPROM_93CX6) += eeprom_93cx6.o
obj-$(CONFIG_EEPROM_93XX46) += eeprom_93xx46.o
obj-$(CONFIG_EEPROM_DIGSY_MTC_CFG) += digsy_mtc_eeprom.o
+obj-$(CONFIG_EEPROM_IDT_89HPESX) += idt_89hpesx.o
diff --git a/drivers/misc/eeprom/idt_89hpesx.c b/drivers/misc/eeprom/idt_89hpesx.c
new file mode 100644
index 0000000..664e315
--- /dev/null
+++ b/drivers/misc/eeprom/idt_89hpesx.c
@@ -0,0 +1,1634 @@
+/*
+ * This file is provided under a GPLv2 license. When using or
+ * redistributing this file, you may do so under that license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright (C) 2016 T-Platforms. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, 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, it can be found <http://www.gnu.org/licenses/>.
+ *
+ * The full GNU General Public License is included in this distribution in
+ * the file called "COPYING".
+ *
+ * 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.
+ *
+ * IDT PCIe-switch NTB Linux driver
+ *
+ * Contact Information:
+ * Serge Semin <fancer.lancer@gmail.com>, <Sergey.Semin@t-platforms.ru>
+ */
+/*
+ * 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/<bus>-<devaddr>/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/<bus>-<devaddr>/<devname>;
+ * <CSR address>:<CSR value>
+ * 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 "<CSR address>" > /sys/kernel/debug/idt_csr/<bus>-<devaddr>/<devname>
+ * If it wants to change the CSR value as well, the format of the write
+ * operation is:
+ * $ echo "<CSR address>:<CSR value>" > \
+ * /sys/kernel/debug/idt_csr/<bus>-<devaddr>/<devname>;
+ * CSR address and value can be any of hexadecimal, decimal or octal format.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/sysfs.h>
+#include <linux/debugfs.h>
+#include <linux/mod_devicetable.h>
+#include <linux/of.h>
+#include <linux/i2c.h>
+#include <linux/pci_ids.h>
+#include <linux/delay.h>
+
+#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
+ * @csr_file: CSR read/write debugfs-node
+ */
+struct idt_smb_seq;
+struct idt_89hpesx_dev {
+ u32 eesize;
+ bool eero;
+ u8 eeaddr;
+
+ u8 inieecmd;
+ u8 inicsrcmd;
+ u8 iniccode;
+
+ atomic_t 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 dentry *csr_file;
+};
+
+/*
+ * 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<reg addr>:0x<value>" for saving register address
+ * and writing value to specified DWORD register or "0x<reg addr>" for
+ * just saving register address in order to perform next read operation.
+ *
+ * WARNING No spaces are allowed. Incoming string must be strictly formated as:
+ * "<reg addr>:<value>". 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, csrval_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(sizeof(char)*(csraddr_len + 1), GFP_KERNEL);
+ if (csraddr_str == NULL)
+ return -ENOMEM;
+ /* 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;
+ csrval_len = strnlen(csrval_str, count - csraddr_len);
+ } else /* if (str_colon == NULL) */ {
+ csraddr_str = (char *)buf; /* Just to shut warning up */
+ csraddr_len = strnlen(csraddr_str, count);
+ csrval_str = NULL;
+ csrval_len = 0;
+ }
+
+ /* 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 */
+ 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, (u16)csraddr, csrval);
+ if (ret != 0)
+ goto free_csraddr_str;
+ }
+
+ /* Save CSR address in the data structure for future read operations */
+ atomic_set(&pdev->csr, (int)csraddr);
+
+ /* 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<reg addr>:0x<value>" 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;
+
+ /* Read current CSR address */
+ csraddr = atomic_read(&pdev->csr);
+
+ /* Perform CSR read operation */
+ ret = idt_csr_read(pdev, (u16)csraddr, &csrval);
+ if (ret != 0)
+ return ret;
+
+ /* Shift register address to the left so to have real address */
+ csraddr <<= 2;
+
+ /* Print the "0x<reg addr>:0x<value>" 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;
+}
+
+#ifdef CONFIG_OF
+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 device_node *node)
+{
+ const struct i2c_device_id *id = ee_ids;
+ char devname[I2C_NAME_SIZE];
+
+ /* Retrieve the device name without manufacturer name */
+ if (of_modalias_node(node, devname, sizeof(devname)))
+ return NULL;
+
+ /* Search through the device name */
+ while (id->name[0]) {
+ if (strcmp(devname, id->name) == 0)
+ return id;
+ id++;
+ }
+ return NULL;
+}
+
+/*
+ * idt_get_ofdata() - get IDT i2c-device parameters from device tree
+ * @pdev: Pointer to the driver data
+ */
+static void idt_get_ofdata(struct idt_89hpesx_dev *pdev)
+{
+ const struct device_node *node = pdev->client->dev.of_node;
+ struct device *dev = &pdev->client->dev;
+
+ /* Read dts node parameters */
+ if (node) {
+ const struct i2c_device_id *ee_id = NULL;
+ struct device_node *child;
+ const __be32 *addr_be;
+ int len;
+
+ /* Walk through all child nodes looking for compatible one */
+ for_each_available_child_of_node(node, child) {
+ ee_id = idt_ee_match_id(child);
+ if (IS_ERR_OR_NULL(ee_id)) {
+ dev_warn(dev, "Skip unsupported child node %s",
+ child->full_name);
+ continue;
+ } else
+ break;
+ }
+
+ /* If there is no child EEPROM device, then set zero size */
+ if (!ee_id) {
+ idt_set_defval(pdev);
+ return;
+ }
+
+ /* Retrieve EEPROM size */
+ pdev->eesize = (u32)ee_id->driver_data;
+
+ /* Get custom EEPROM address from 'reg' attribute */
+ addr_be = of_get_property(child, "reg", &len);
+ if (!addr_be || (len < sizeof(*addr_be))) {
+ dev_warn(dev, "No reg on %s, use default address %d",
+ child->full_name, EEPROM_DEF_ADDR);
+ pdev->inieecmd = 0;
+ pdev->eeaddr = EEPROM_DEF_ADDR << 1;
+ } else {
+ pdev->inieecmd = EEPROM_USA;
+ pdev->eeaddr = be32_to_cpup(addr_be) << 1;
+ }
+
+ /* Check EEPROM 'read-only' flag */
+ if (of_get_property(child, "read-only", NULL))
+ pdev->eero = true;
+ else /* if (!of_get_property(node, "read-only", NULL)) */
+ pdev->eero = false;
+
+ dev_dbg(dev, "EEPROM of %u bytes found by %hhu",
+ pdev->eesize, pdev->eeaddr);
+ } else {
+ dev_warn(dev, "No dts node, EEPROM access disabled");
+ idt_set_defval(pdev);
+ }
+}
+#else
+static void idt_get_ofdata(struct idt_89hpesx_dev *pdev)
+{
+ struct device *dev = &pdev->client->dev;
+
+ dev_warn(dev, "OF table is unsupported, EEPROM access disabled");
+
+ /* Nothing we can do, just set the default values */
+ idt_set_defval(pdev);
+}
+#endif /* CONFIG_OF */
+
+/*
+ * 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 OF nodes information */
+ idt_get_ofdata(pdev);
+
+ /* Initialize basic CSR CMD field - use full DWORD-sized r/w ops */
+ pdev->inicsrcmd = CSR_DWE;
+ atomic_set(&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;
+ }
+
+ dev_dbg(&client->dev, "IDT 89HPESx data created");
+
+ 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);
+
+ /* Just free memory allocated for data */
+ devm_kfree(&pdev->client->dev, pdev);
+
+ dev_dbg(&pdev->client->dev, "IDT 89HPESx data discarded");
+}
+
+/*
+ * 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);
+
+ dev_dbg(dev, "SMBus functionality successfully checked");
+
+ 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) {
+ kfree(pdev->ee_file);
+ dev_err(dev, "Failed to create EEPROM sysfs-node");
+ return ret;
+ }
+
+ dev_dbg(dev, "Sysfs-files created");
+
+ 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);
+
+ /* Free memory allocated for bin_attribute structure */
+ kfree(pdev->ee_file);
+
+ dev_dbg(dev, "Sysfs-files removed");
+}
+
+/*
+ * idt_create_dbgfs_files() - create debugfs files
+ * @pdev: Pointer to the driver data
+ * Return status of operation
+ */
+#define CSRNAME_LEN ((size_t)32)
+static int idt_create_dbgfs_files(struct idt_89hpesx_dev *pdev)
+{
+ struct device *dev = &pdev->client->dev;
+ struct i2c_client *cli = pdev->client;
+ char fname[CSRNAME_LEN];
+
+ /* Initialize basic value of CSR debugfs dentries */
+ pdev->csr_dir = NULL;
+ pdev->csr_file = NULL;
+
+ /* Return failure if root directory doesn't exist */
+ if (!csr_dbgdir) {
+ dev_dbg(dev, "No Debugfs root directory");
+ return -EINVAL;
+ }
+
+ /* 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);
+ if (IS_ERR_OR_NULL(pdev->csr_dir)) {
+ dev_err(dev, "Failed to create CSR node directory");
+ return -EINVAL;
+ }
+
+ /* Create Debugfs file for CSR read/write operations */
+ pdev->csr_file = debugfs_create_file(cli->name, 0600,
+ pdev->csr_dir, pdev, &csr_dbgfs_ops);
+ if (IS_ERR_OR_NULL(pdev->csr_file)) {
+ dev_err(dev, "Failed to create CSR dbgfs-node");
+ debugfs_remove_recursive(pdev->csr_dir);
+ return -EINVAL;
+ }
+
+ dev_dbg(dev, "Debugfs-files created");
+
+ return 0;
+}
+
+/*
+ * 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);
+
+ dev_dbg(&pdev->client->dev, "Debugfs-files removed");
+}
+
+/*
+ * 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 */
+ (void)idt_create_dbgfs_files(pdev);
+
+ dev_dbg(&client->dev, "IDT %s device probed", id->name);
+
+ 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);
+
+ dev_dbg(&client->dev, "IDT 89HPESx device removed");
+
+ 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);
+
+/*
+ * idt_driver - IDT 89HPESx driver structure
+ */
+static struct i2c_driver idt_driver = {
+ .driver = {
+ .name = IDT_NAME,
+ .owner = THIS_MODULE,
+ },
+ .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);
--
2.6.6
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  Last update: 2016-12-13 15:24    [W:0.252 / U:0.296 seconds]
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