[PATCH] Add IDT 89HPESx EEPROM/CSR driver
From: Serge Semin
Date: Sun Oct 02 2016 - 19:16:09 EST
Hello linux folks,
This driver primarily is developed to give an access to EEPROM of IDT
PCIe-switches. Such switches provide a simple SMBus interface to perform
IO-operations from/to EEPROM, which is located at private (also called master)
SMBus of the switches. Using that interface this 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 device dts-node, user-space
applications won't be able to write to the EEPROM sysfs-node.
Additionally IDT 89HPESx SMBus interface provides an ability to write/read
data of device CSRs. This driver exposes corresponding sysfs-file to perform
simple IO operations using that facility for just basic debug purpose.
Particularly next file is created in the device specific sysfs-directory:
/sys/bus/i2c/devices/<bus>-<devaddr>/csr
Format of the sysfs-node is:
$ cat /sys/bus/i2c/devices/<bus>-<devaddr>/csr;
<CSR address>:<CSR value>
So reading the content of the sysfs-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/bus/i2c/devices/<bus>-<devaddr>/csr
If it wants to change the CSR value as well, the format of the write
operation is:
$ echo "<CSR address>:<CSR value>" > \
/sys/bus/i2c/devices/<bus>-<devaddr>/csr;
CSR address and value can be any of hexadecimal, decimal or octal format.
The driver supports the most of the commonly available SMBus operations:
SMBus i2c block, SMBus block, smbus word and byte. The code has been tested
to be built for x32/x64 MIPS architecture and tested on the x32 MIPS machine.
The patch was applied on top of commit c6935931c1894ff857616ff8549b61236a19148f
of master branch of repository
git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
Thanks,
=============================
Serge V. Semin
Leading Programmer
Embedded SW development group
T-platforms
=============================
Signed-off-by: Serge Semin <fancer.lancer@xxxxxxxxx>
---
.../devicetree/bindings/misc/idt_89hpesx.txt | 41 +
drivers/misc/eeprom/Kconfig | 10 +
drivers/misc/eeprom/Makefile | 1 +
drivers/misc/eeprom/idt_89hpesx.c | 1483 ++++++++++++++++++++
4 files changed, 1535 insertions(+)
create mode 100644 Documentation/devicetree/bindings/misc/idt_89hpesx.txt
create mode 100644 drivers/misc/eeprom/idt_89hpesx.c
diff --git a/Documentation/devicetree/bindings/misc/idt_89hpesx.txt b/Documentation/devicetree/bindings/misc/idt_89hpesx.txt
new file mode 100644
index 0000000..469cc93
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/idt_89hpesx.txt
@@ -0,0 +1,41 @@
+EEPROM / CSR SMBus-slave interface of IDT 89HPESx devices
+
+Required properties:
+ - compatible : should be "<manufacturer>,<type>"
+ Basically there is only one manufacturer: idt, but some
+ compatible devices may be produced in future. Following devices
+ are supported: 89hpes8nt2, 89hpes12nt3, 89hpes24nt6ag2,
+ 89hpes32nt8ag2, 89hpes32nt8bg2, 89hpes12nt12g2, 89hpes16nt16g2,
+ 89hpes24nt24g2, 89hpes32nt24ag2, 89hpes32nt24bg2;
+ 89hpes12n3, 89hpes12n3a, 89hpes24n3, 89hpes24n3a;
+ 89hpes32h8, 89hpes32h8g2, 89hpes48h12, 89hpes48h12g2,
+ 89hpes48h12ag2, 89hpes16h16, 89hpes22h16, 89hpes22h16g2,
+ 89hpes34h16, 89hpes34h16g2, 89hpes64h16, 89hpes64h16g2,
+ 89hpes64h16ag2;
+ 89hpes12t3g2, 89hpes24t3g2, 89hpes16t4, 89hpes4t4g2,
+ 89hpes10t4g2, 89hpes16t4g2, 89hpes16t4ag2, 89hpes5t5,
+ 89hpes6t5, 89hpes8t5, 89hpes8t5a, 89hpes24t6, 89hpes6t6g2,
+ 89hpes24t6g2, 89hpes16t7, 89hpes32t8, 89hpes32t8g2,
+ 89hpes48t12, 89hpes48t12g2.
+ Current implementation of the driver doesn't have any device-
+ specific functionalities. But since each of them differs
+ by registers mapping, CSRs read/write restrictions can be
+ added in future.
+ - reg : I2C address of the IDT 89HPES device.
+
+Optional properties:
+ - read-only : Parameterless property disables writes to the EEPROM
+ - idt,eesize : Size of EEPROM device connected to IDT 89HPES i2c-master bus
+ (default value is 4096 bytes if option isn't specified)
+ - idt,eeaddr : Custom address of EEPROM device
+ (If not specified IDT 89HPESx device will try to communicate
+ with EEPROM sited by default address - 0x50)
+
+Example:
+ idt_pcie_sw@60 {
+ compatible = "idt,89hpes12nt3";
+ reg = <0x60>;
+ read-only;
+ idt,eesize = <65536>;
+ idt,eeaddr = <0x50>;
+ };
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..f95f4f0
--- /dev/null
+++ b/drivers/misc/eeprom/idt_89hpesx.c
@@ -0,0 +1,1483 @@
+/*
+ * 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@xxxxxxxxx>, <Sergey.Semin@xxxxxxxxxxxxxx>
+ */
+/*
+ * 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 another sysfs-file to perform
+ * simple IO operations using that ability for just basic debug purpose.
+ * Particularly next file is created in the device specific sysfs-directory:
+ * /sys/bus/i2c/devices/<bus>-<devaddr>/csr
+ * Format of the sysfs-node is:
+ * $ cat /sys/bus/i2c/devices/<bus>-<devaddr>/csr;
+ * <CSR address>:<CSR value>
+ * So reading the content of the sysfs-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/bus/i2c/devices/<bus>-<devaddr>/csr
+ * If it wants to change the CSR value as well, the format of the write
+ * operation is:
+ * $ echo "<CSR address>:<CSR value>" > \
+ * /sys/bus/i2c/devices/<bus>-<devaddr>/csr;
+ * CSR address and value can be any of hexadecimal, decimal or octal format.
+ */
+
+/*
+ * Note: You can load this module with either option 'dyndbg=+p' or define the
+ * next preprocessor constant
+ */
+/* #define DEBUG */
+
+#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/mod_devicetable.h>
+#include <linux/of.h>
+#include <linux/i2c.h>
+#include <linux/pci_ids.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");
+
+/*
+ * Some common constant used in the driver for better readability:
+ * @SUCCESS: Success of a function execution
+ */
+#define SUCCESS (0)
+
+/*
+ * 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
+ *
+ * @eenode: EEPROM sysfs-node to read/write data to/from EEPROM
+ * @regnode: Register sysfs-node to read/write CSRs
+ */
+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 eenode;
+ struct bin_attribute regnode;
+};
+#define to_pdev_kobj(__kobj) \
+ dev_get_drvdata(container_of(__kobj, struct device, kobj))
+
+/*
+ * 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
+ */
+#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)
+
+/*
+ * 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 < SUCCESS); \
+ __sts; \
+})
+
+/*
+ * Wrapper dev_err/dev_warn/dev_info/dev_dbg macros
+ */
+#define dev_err_idt(pdev, args...) \
+ dev_err(&pdev->client->dev, ## args)
+#define dev_warn_idt(pdev, args...) \
+ dev_warn(&pdev->client->dev, ## args)
+#define dev_info_idt(pdev, args...) \
+ dev_info(&pdev->client->dev, ## args)
+#define dev_dbg_idt(pdev, args...) \
+ dev_dbg(&pdev->client->dev, ## args)
+
+/*===========================================================================
+ * 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 != SUCCESS)
+ return (int)sts;
+ }
+
+ return SUCCESS;
+}
+
+/*
+ * 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 < SUCCESS)
+ return (int)sts;
+
+ seq->data[idx] = (u8)sts;
+ }
+
+ return SUCCESS;
+}
+
+/*
+ * 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 != SUCCESS)
+ 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 != SUCCESS)
+ return (int)sts;
+ }
+
+ return SUCCESS;
+}
+
+/*
+ * 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 < SUCCESS)
+ 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 < SUCCESS)
+ return (int)sts;
+
+ seq->data[idx] = (u8)sts;
+ }
+
+ return SUCCESS;
+}
+
+/*
+ * 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 < SUCCESS ? sts : -ENODATA);
+
+ return SUCCESS;
+}
+
+/*
+ * 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 < SUCCESS ? 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 SUCCESS;
+}
+
+/*===========================================================================
+ * EEPROM IO-operations
+ *===========================================================================
+ */
+
+/*
+ * 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 idt_eeprom_seq eeseq;
+ struct idt_smb_seq smbseq;
+ int ret, retry;
+ 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 != SUCCESS) {
+ dev_err_idt(pdev,
+ "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. Sometimes EEPROM may
+ * respond with NACK if it's busy with writing previous data,
+ * 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;
+ ret = pdev->smb_write(pdev, &smbseq);
+ if (ret != SUCCESS) {
+ dev_err_idt(pdev,
+ "Failed to init mem address 0x%02hhx",
+ memaddr);
+ goto err_mutex_unlock;
+ }
+
+ /* Perform read operation */
+ smbseq.bytecnt = EEPROM_RD_CNT;
+ eeseq.data = ~data[idx];
+ ret = pdev->smb_read(pdev, &smbseq);
+ if (ret != SUCCESS) {
+ dev_err_idt(pdev,
+ "Failed to read mem address 0x%02hhx",
+ memaddr);
+ goto err_mutex_unlock;
+ }
+ } while (retry-- && (eeseq.cmd & EEPROM_NAERR));
+
+ /* Check whether IDT successfully sent data to EEPROM */
+ if (eeseq.cmd & (EEPROM_NAERR | EEPROM_LAERR | EEPROM_MSS)) {
+ dev_err_idt(pdev, "Communication with EEPROM failed");
+ ret = -EREMOTEIO;
+ goto err_mutex_unlock;
+ }
+ if (eeseq.data != data[idx]) {
+ dev_err_idt(pdev,
+ "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 != SUCCESS)
+ return ret;
+ }
+
+ return SUCCESS;
+}
+
+/*
+ * 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)
+{
+ struct idt_eeprom_seq eeseq;
+ struct idt_smb_seq smbseq;
+ u16 idx;
+ int ret;
+
+ /* Initialize SMBus sequence fields */
+ smbseq.ccode = pdev->iniccode | CCODE_EEPROM;
+ smbseq.data = (u8 *)&eeseq;
+
+ /* Send data one-by-one, checking if it is successfully written */
+ for (idx = 0; idx < len; idx++, memaddr++) {
+ /* Lock IDT SMBus device */
+ mutex_lock(&pdev->smb_mtx);
+
+ /* 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 != SUCCESS) {
+ dev_err_idt(pdev, "Failed to init mem address 0x%02hhx",
+ memaddr);
+ goto err_mutex_unlock;
+ }
+
+ /* Perform read operation (rest of fields stay the same) */
+ smbseq.bytecnt = EEPROM_RD_CNT;
+ ret = pdev->smb_read(pdev, &smbseq);
+ if (ret != SUCCESS) {
+ dev_err_idt(pdev,
+ "Failed to read eeprom address 0x%02hhx",
+ memaddr);
+ ret = -EREMOTEIO;
+ goto err_mutex_unlock;
+ }
+
+ /* Check whether IDT successfully read data from EEPROM */
+ if (eeseq.cmd & (EEPROM_NAERR | EEPROM_LAERR | EEPROM_MSS)) {
+ dev_err_idt(pdev, "Communication with eeprom failed");
+ ret = -EREMOTEIO;
+ goto err_mutex_unlock;
+ }
+
+ /* Save retrieved data */
+ buf[idx] = eeseq.data;
+
+ /* Unlock IDT SMBus device */
+err_mutex_unlock:
+ mutex_unlock(&pdev->smb_mtx);
+ if (ret != SUCCESS)
+ return ret;
+ }
+
+ return SUCCESS;
+}
+
+/*===========================================================================
+ * 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 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 != SUCCESS) {
+ dev_err_idt(pdev, "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 != SUCCESS) {
+ dev_err_idt(pdev, "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 != SUCCESS) {
+ dev_err_idt(pdev, "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_idt(pdev, "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 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 != SUCCESS) {
+ dev_err_idt(pdev, "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 != SUCCESS) {
+ dev_err_idt(pdev, "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_idt(pdev, "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-nodes IO-operations
+ *===========================================================================
+ */
+
+/*
+ * idt_sysfs_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 idt_sysfs_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 = to_pdev_kobj(kobj);
+
+ /* Perform EEPROM write operation */
+ ret = idt_eeprom_write(pdev, (u16)off, (u16)count, (u8 *)buf);
+ return (ret != SUCCESS ? ret : count);
+}
+
+/*
+ * idt_sysfs_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 idt_sysfs_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 = to_pdev_kobj(kobj);
+
+ /* Perform EEPROM read operation */
+ ret = idt_eeprom_read(pdev, (u16)off, (u16)count, (u8 *)buf);
+ return (ret != SUCCESS ? ret : count);
+}
+
+/*
+ * idt_sysfs_csr_store() - CSR sysfs-node write callback
+ * @kobj: Pointer to the kernel object related to the sysfs-node
+ * @attr: Attributes of the file
+ * @buf: Buffer to write data to
+ * @count: Size of the buffer
+ *
+ * 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_sysfs_csr_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct idt_89hpesx_dev *pdev;
+ char *colon_ch, *csraddr_str, *csrval_str;
+ int ret, csraddr_len, csrval_len;
+ u32 csraddr, csrval;
+
+ /* Retrieve driver data */
+ pdev = dev_get_drvdata(dev);
+
+ /* 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 != SUCCESS)
+ 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 != SUCCESS)
+ goto free_csraddr_str;
+
+ ret = idt_csr_write(pdev, (u16)csraddr, csrval);
+ if (ret != SUCCESS)
+ 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);
+
+ return (ret != SUCCESS ? ret : count);
+}
+
+/*
+ * idt_sysfs_csr_show() - CSR sysfs-node read callback
+ * @kobj: Pointer to the kernel object related to the sysfs-node
+ * @attr: Attributes of the file
+ * @buf: Buffer to write data to
+ *
+ * It just prints the pair "0x<reg addr>:0x<value>" to passed buffer.
+ */
+static ssize_t idt_sysfs_csr_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct idt_89hpesx_dev *pdev;
+ u32 csraddr, csrval;
+ int ret;
+
+ /* Retrieve driver data */
+ pdev = dev_get_drvdata(dev);
+
+ /* Read current CSR address */
+ csraddr = atomic_read(&pdev->csr);
+
+ /* Perform CSR read operation */
+ ret = idt_csr_read(pdev, (u16)csraddr, &csrval);
+ if (ret != SUCCESS)
+ return ret;
+
+ /* Shift register address to the left so to have real address */
+ csraddr <<= 2;
+
+ /* Print the "0x<reg addr>:0x<value>" to buffer */
+ return snprintf(buf, PAGE_SIZE, "0x%05x:0x%08x\n",
+ (unsigned int)csraddr, (unsigned int)csrval);
+}
+
+/*
+ * 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 struct bin_attribute eeprom_attribute = {
+ .attr = {
+ .name = "eeprom",
+ .mode = S_IRUGO | S_IWUSR
+ },
+ .size = EEPROM_DEF_SIZE,
+ .write = idt_sysfs_eeprom_write,
+ .read = idt_sysfs_eeprom_read
+};
+
+/*
+ * csr_attribute - CSR sysfs-node attributes
+ */
+static struct device_attribute csr_attribute = {
+ .attr = {
+ .name = "csr",
+ .mode = S_IRUGO | S_IWUSR
+ },
+ .store = idt_sysfs_csr_store,
+ .show = idt_sysfs_csr_show,
+};
+
+/*===========================================================================
+ * Driver init/deinit methods
+ *===========================================================================
+ */
+
+/*
+ * idt_set_defval() - set default device data parameters
+ * @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 = EEPROM_DEF_SIZE;
+ pdev->eero = true;
+ pdev->inieecmd = 0;
+ pdev->eeaddr = EEPROM_DEF_ADDR << 1;
+}
+
+#ifdef CONFIG_OF
+/*
+ * 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)
+{
+ struct device_node *node = pdev->client->dev.of_node;
+ const __be32 *val;
+
+ /* Read dts node parameters */
+ if (node) {
+ /* Get EEPROM size from 'idt,eesize' */
+ val = of_get_property(node, "idt,eesize", NULL);
+ if (val != NULL) {
+ pdev->eesize = be32_to_cpup(val);
+ if (!is_power_of_2(pdev->eesize))
+ dev_warn_idt(pdev,
+ "EEPROM size %u is not power of 2",
+ pdev->eesize);
+ } else /* if (val == NULL) */ {
+ pdev->eesize = EEPROM_DEF_SIZE;
+ dev_warn_idt(pdev,
+ "No EEPROM size, set default %u bytes",
+ pdev->eesize);
+ }
+
+ /* Get custom EEPROM address from 'idt,eeaddr' */
+ val = of_get_property(node, "idt,eeaddr", NULL);
+ if (val != NULL) {
+ pdev->inieecmd = EEPROM_USA;
+ pdev->eeaddr = be32_to_cpup(val) << 1;
+ } else /* if (val != NULL) */ {
+ pdev->inieecmd = 0;
+ pdev->eeaddr = EEPROM_DEF_ADDR << 1;
+ }
+
+ /* Check EEPROM 'read-only' flag */
+ if (of_get_property(node, "read-only", NULL))
+ pdev->eero = true;
+ else /* if (!of_get_property(node, "read-only", NULL)) */
+ pdev->eero = false;
+ } else {
+ dev_warn_idt(pdev, "No dts node, set default values");
+ idt_set_defval(pdev);
+ }
+}
+#else
+static void idt_get_ofdata(struct idt_89hpesx_dev *pdev)
+{
+ dev_warn_idt(pdev, "OF table is unsupported, set default values");
+
+ /* 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_idt(pdev, "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_idt(pdev, "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;
+
+ /* 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_idt(pdev, "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_idt(pdev, "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_idt(pdev, "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_idt(pdev, "Use slow byte SMBus read op");
+ } else /* no supported smbus read operations */ {
+ dev_err_idt(pdev, "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_idt(pdev, "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_idt(pdev, "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_idt(pdev, "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_idt(pdev, "Use slow byte SMBus write op");
+ } else /* no supported smbus write operations */ {
+ dev_err_idt(pdev, "No supported SMBus write op");
+ return -EPFNOSUPPORT;
+ }
+
+ /* Initialize IDT SMBus slave interface mutex */
+ mutex_init(&pdev->smb_mtx);
+
+ dev_dbg_idt(pdev, "SMBus functionality successfully checked");
+
+ return SUCCESS;
+}
+
+/*
+ * 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)
+{
+ u32 viddid;
+ int ret;
+
+ /* Read VID and DID directly from IDT memory space */
+ ret = idt_csr_read(pdev, IDT_VIDDID_CSR, &viddid);
+ if (ret != SUCCESS) {
+ dev_err_idt(pdev, "Failed to read VID/DID");
+ return ret;
+ }
+
+ /* Check whether it's IDT device */
+ if ((viddid & IDT_VID_MASK) != PCI_VENDOR_ID_IDT) {
+ dev_err_idt(pdev, "Got unsupported VID/DID: 0x%08x", viddid);
+ return -ENODEV;
+ }
+
+ dev_info_idt(pdev, "Found IDT 89HPES device VID:0x%04x, DID:0x%04x",
+ (viddid & IDT_VID_MASK), (viddid >> 16));
+
+ return SUCCESS;
+}
+
+/*
+ * 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;
+
+ /* In case of read-only EEPROM get rid of write ability */
+ if (pdev->eero) {
+ eeprom_attribute.attr.mode &= ~S_IWUSR;
+ eeprom_attribute.write = NULL;
+ }
+ /* Create EEPROM sysfs file */
+ eeprom_attribute.size = pdev->eesize;
+ ret = sysfs_create_bin_file(&dev->kobj, &eeprom_attribute);
+ if (ret != SUCCESS) {
+ dev_err_idt(pdev, "Failed to create EEPROM sysfs-node");
+ return ret;
+ }
+
+ /* Create CSR sysfs file */
+ ret = sysfs_create_file(&dev->kobj, &csr_attribute.attr);
+ if (ret != SUCCESS) {
+ dev_err_idt(pdev, "Failed to create CSR sysfs-node");
+ sysfs_remove_bin_file(&dev->kobj, &eeprom_attribute);
+ return ret;
+ }
+
+ dev_dbg_idt(pdev, "Sysfs-files created");
+
+ return SUCCESS;
+}
+
+/*
+ * 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;
+
+ /* Remove CSR sysfs file */
+ sysfs_remove_file(&dev->kobj, &csr_attribute.attr);
+
+ /* Remove EEPROM sysfs file */
+ sysfs_remove_bin_file(&dev->kobj, &eeprom_attribute);
+
+ dev_dbg_idt(pdev, "Sysfs-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 != SUCCESS)
+ goto err_free_pdev;
+
+ /* Check whether it is truly IDT 89HPESx device */
+ ret = idt_check_dev(pdev);
+ if (ret != SUCCESS)
+ goto err_free_pdev;
+
+ /* Create sysfs files */
+ ret = idt_create_sysfs_files(pdev);
+ if (ret != SUCCESS)
+ goto err_free_pdev;
+
+ dev_dbg_idt(pdev, "IDT %s device probed", id->name);
+
+ return SUCCESS;
+
+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 sysfs files first */
+ idt_remove_sysfs_files(pdev);
+
+ /* Discard driver data structure */
+ idt_free_pdev(pdev);
+
+ dev_dbg_idt(pdev, "IDT 89HPESx device removed");
+
+ return SUCCESS;
+}
+
+/*
+ * 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,
+};
+module_i2c_driver(idt_driver);
+
--
2.6.6