+
+static int ipath_tempsense_internal_read(struct ipath_devdata *dd, u8 regnum)
+{
+ int ret;
+ struct i2c_chain_desc *icd;
+
+ ret = -ENOENT;
+
+ icd = ipath_i2c_type(dd);
+ if (!icd)
+ goto bail;
+
+ if (icd->temp_dev == IPATH_NO_DEV) {
+ /* tempsense only exists on new, real-I2C boards */
+ ret = -ENXIO;
+ goto bail;
+ }
+
+ if (i2c_startcmd(dd, icd->temp_dev | WRITE_CMD)) {
+ ipath_dbg("Failed tempsense startcmd\n");
+ stop_cmd(dd);
+ ret = -ENXIO;
+ goto bail;
+ }
+ ret = wr_byte(dd, regnum);
+ stop_cmd(dd);
+ if (ret) {
+ ipath_dev_err(dd, "Failed tempsense WR command %02X\n",
+ regnum);
+ ret = -ENXIO;
+ goto bail;
+ }
+ if (i2c_startcmd(dd, icd->temp_dev | READ_CMD)) {
+ ipath_dbg("Failed tempsense RD startcmd\n");
+ stop_cmd(dd);
+ ret = -ENXIO;
+ goto bail;
+ }
+ /*
+ * We can only clock out one byte per command, sensibly
+ */
+ ret = rd_byte(dd);
+ stop_cmd(dd);
+
+bail:
+ return ret;
+}
+
+#define VALID_TS_RD_REG_MASK 0xBF
+
+/**
+ * ipath_tempsense_read - read register of temp sensor via I2C
+ * @dd: the infinipath device
+ * @regnum: register to read from
+ *
+ * returns reg contents (0..255) or < 0 for error
+ */
+int ipath_tempsense_read(struct ipath_devdata *dd, u8 regnum)
+{
+ int ret;
+
+ if (regnum > 7)
+ return -EINVAL;
+
+ /* return a bogus value for (the one) register we do not have */
+ if (!((1 << regnum) & VALID_TS_RD_REG_MASK))
+ return 0;
+
+ ret = mutex_lock_interruptible(&dd->ipath_eep_lock);
+ if (!ret) {
+ ret = ipath_tempsense_internal_read(dd, regnum);
+ mutex_unlock(&dd->ipath_eep_lock);
+ }
+
+ /*
+ * There are three possibilities here:
+ * ret is actual value (0..255)
+ * ret is -ENXIO or -EINVAL from code in this file
+ * ret is -EINTR from mutex_lock_interruptible.
+ */
+ return ret;
+}
+
+static int ipath_tempsense_internal_write(struct ipath_devdata *dd,
+ u8 regnum, u8 data)
+{
+ int ret = -ENOENT;
+ struct i2c_chain_desc *icd;
+
+ icd = ipath_i2c_type(dd);
+ if (!icd)
+ goto bail;
+
+ if (icd->temp_dev == IPATH_NO_DEV) {
+ /* tempsense only exists on new, real-I2C boards */
+ ret = -ENXIO;
+ goto bail;
+ }
+ if (i2c_startcmd(dd, icd->temp_dev | WRITE_CMD)) {
+ ipath_dbg("Failed tempsense startcmd\n");
+ stop_cmd(dd);
+ ret = -ENXIO;
+ goto bail;
+ }
+ ret = wr_byte(dd, regnum);
+ if (ret) {
+ stop_cmd(dd);
+ ipath_dev_err(dd, "Failed to write tempsense command %02X\n",
+ regnum);
+ ret = -ENXIO;
+ goto bail;
+ }
+ ret = wr_byte(dd, data);
+ stop_cmd(dd);
+ ret = i2c_startcmd(dd, icd->temp_dev | READ_CMD);
+ if (ret) {
+ ipath_dev_err(dd, "Failed tempsense data wrt to %02X\n",
+ regnum);
+ ret = -ENXIO;
+ }
+
+bail:
+ return ret;
+}
+
+#define VALID_TS_WR_REG_MASK ((1 << 9) | (1 << 0xB) | (1 << 0xD))
+
+/**
+ * ipath_tempsense_write - write register of temp sensor via I2C
+ * @dd: the infinipath device
+ * @regnum: register to write
+ * @data: data to write
+ *
+ * returns 0 for success or < 0 for error
+ */
+int ipath_tempsense_write(struct ipath_devdata *dd, u8 regnum, u8 data)
+{
+ int ret;
+
+ if (regnum > 15 || !((1 << regnum) & VALID_TS_WR_REG_MASK))
+ return -EINVAL;
+
+ ret = mutex_lock_interruptible(&dd->ipath_eep_lock);
+ if (!ret) {
+ ret = ipath_tempsense_internal_write(dd, regnum, data);
+ mutex_unlock(&dd->ipath_eep_lock);
+ }
+
+ /*
+ * There are three possibilities here:
+ * ret is 0 for success
+ * ret is -ENXIO or -EINVAL from code in this file
+ * ret is -EINTR from mutex_lock_interruptible.
+ */
+ return ret;
+}