IB/ipath: EEPROM support for 7220 devices, robustness improvements, cleanup

Add support for reading newer card's EEPROMs while continuing to support
older EEPROMs.

Also, add support for the temperature sensor if present.

Signed-off-by: Michael Albaugh <Michael.Albaugh@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 361 insertions, 65 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_eeprom.c b/drivers/infiniband/hw/ipath/ipath_eeprom.c
index e28a42f53769..72f90e8d5f76 100644
--- a/drivers/infiniband/hw/ipath/ipath_eeprom.c
+++ b/drivers/infiniband/hw/ipath/ipath_eeprom.c
@@ -62,6 +62,33 @@
  * accessing eeprom contents from within the kernel, only via sysfs.
  */
 
+/* Added functionality for IBA7220-based cards */
+#define IPATH_EEPROM_DEV_V1 0xA0
+#define IPATH_EEPROM_DEV_V2 0xA2
+#define IPATH_TEMP_DEV 0x98
+#define IPATH_BAD_DEV (IPATH_EEPROM_DEV_V2+2)
+#define IPATH_NO_DEV (0xFF)
+
+/*
+ * The number of I2C chains is proliferating. Table below brings
+ * some order to the madness. The basic principle is that the
+ * table is scanned from the top, and a "probe" is made to the
+ * device probe_dev. If that succeeds, the chain is considered
+ * to be of that type, and dd->i2c_chain_type is set to the index+1
+ * of the entry.
+ * The +1 is so static initialization can mean "unknown, do probe."
+ */
+static struct i2c_chain_desc {
+	u8 probe_dev;	/* If seen at probe, chain is this type */
+	u8 eeprom_dev;	/* Dev addr (if any) for EEPROM */
+	u8 temp_dev;	/* Dev Addr (if any) for Temp-sense */
+} i2c_chains[] = {
+	{ IPATH_BAD_DEV, IPATH_NO_DEV, IPATH_NO_DEV }, /* pre-iba7220 bds */
+	{ IPATH_EEPROM_DEV_V1, IPATH_EEPROM_DEV_V1, IPATH_TEMP_DEV}, /* V1 */
+	{ IPATH_EEPROM_DEV_V2, IPATH_EEPROM_DEV_V2, IPATH_TEMP_DEV}, /* V2 */
+	{ IPATH_NO_DEV }
+};
+
 enum i2c_type {
 	i2c_line_scl = 0,
 	i2c_line_sda
@@ -75,13 +102,6 @@ enum i2c_state {
 #define READ_CMD 1
 #define WRITE_CMD 0
 
-static int eeprom_init;
-
-/*
- * The gpioval manipulation really should be protected by spinlocks
- * or be converted to use atomic operations.
- */
-
 /**
  * i2c_gpio_set - set a GPIO line
  * @dd: the infinipath device
@@ -241,6 +261,27 @@ static int i2c_ackrcv(struct ipath_devdata *dd)
 }
 
 /**
+ * rd_byte - read a byte, leaving ACK, STOP, etc up to caller
+ * @dd: the infinipath device
+ *
+ * Returns byte shifted out of device
+ */
+static int rd_byte(struct ipath_devdata *dd)
+{
+	int bit_cntr, data;
+
+	data = 0;
+
+	for (bit_cntr = 7; bit_cntr >= 0; --bit_cntr) {
+		data <<= 1;
+		scl_out(dd, i2c_line_high);
+		data |= sda_in(dd, 0);
+		scl_out(dd, i2c_line_low);
+	}
+	return data;
+}
+
+/**
  * wr_byte - write a byte, one bit at a time
  * @dd: the infinipath device
  * @data: the byte to write
@@ -331,7 +372,6 @@ static int eeprom_reset(struct ipath_devdata *dd)
 	ipath_cdbg(VERBOSE, "Resetting i2c eeprom; initial gpioout reg "
 		   "is %llx\n", (unsigned long long) *gpioval);
 
-	eeprom_init = 1;
 	/*
 	 * This is to get the i2c into a known state, by first going low,
 	 * then tristate sda (and then tristate scl as first thing
@@ -340,12 +380,17 @@ static int eeprom_reset(struct ipath_devdata *dd)
 	scl_out(dd, i2c_line_low);
 	sda_out(dd, i2c_line_high);
 
+	/* Clock up to 9 cycles looking for SDA hi, then issue START and STOP */
 	while (clock_cycles_left--) {
 		scl_out(dd, i2c_line_high);
 
+		/* SDA seen high, issue START by dropping it while SCL high */
 		if (sda_in(dd, 0)) {
 			sda_out(dd, i2c_line_low);
 			scl_out(dd, i2c_line_low);
+			/* ATMEL spec says must be followed by STOP. */
+			scl_out(dd, i2c_line_high);
+			sda_out(dd, i2c_line_high);
 			ret = 0;
 			goto bail;
 		}
@@ -359,29 +404,121 @@ bail:
 	return ret;
 }
 
-/**
- * ipath_eeprom_read - receives bytes from the eeprom via I2C
- * @dd: the infinipath device
- * @eeprom_offset: address to read from
- * @buffer: where to store result
- * @len: number of bytes to receive
+/*
+ * Probe for I2C device at specified address. Returns 0 for "success"
+ * to match rest of this file.
+ * Leave bus in "reasonable" state for further commands.
  */
+static int i2c_probe(struct ipath_devdata *dd, int devaddr)
+{
+	int ret = 0;
+
+	ret = eeprom_reset(dd);
+	if (ret) {
+		ipath_dev_err(dd, "Failed reset probing device 0x%02X\n",
+			      devaddr);
+		return ret;
+	}
+	/*
+	 * Reset no longer leaves bus in start condition, so normal
+	 * i2c_startcmd() will do.
+	 */
+	ret = i2c_startcmd(dd, devaddr | READ_CMD);
+	if (ret)
+		ipath_cdbg(VERBOSE, "Failed startcmd for device 0x%02X\n",
+			   devaddr);
+	else {
+		/*
+		 * Device did respond. Complete a single-byte read, because some
+		 * devices apparently cannot handle STOP immediately after they
+		 * ACK the start-cmd.
+		 */
+		int data;
+		data = rd_byte(dd);
+		stop_cmd(dd);
+		ipath_cdbg(VERBOSE, "Response from device 0x%02X\n", devaddr);
+	}
+	return ret;
+}
+
+/*
+ * Returns the "i2c type". This is a pointer to a struct that describes
+ * the I2C chain on this board. To minimize impact on struct ipath_devdata,
+ * the (small integer) index into the table is actually memoized, rather
+ * then the pointer.
+ * Memoization is because the type is determined on the first call per chip.
+ * An alternative would be to move type determination to early
+ * init code.
+ */
+static struct i2c_chain_desc *ipath_i2c_type(struct ipath_devdata *dd)
+{
+	int idx;
+
+	/* Get memoized index, from previous successful probes */
+	idx = dd->ipath_i2c_chain_type - 1;
+	if (idx >= 0 && idx < (ARRAY_SIZE(i2c_chains) - 1))
+		goto done;
+
+	idx = 0;
+	while (i2c_chains[idx].probe_dev != IPATH_NO_DEV) {
+		/* if probe succeeds, this is type */
+		if (!i2c_probe(dd, i2c_chains[idx].probe_dev))
+			break;
+		++idx;
+	}
+
+	/*
+	 * Old EEPROM (first entry) may require a reset after probe,
+	 * rather than being able to "start" after "stop"
+	 */
+	if (idx == 0)
+		eeprom_reset(dd);
+
+	if (i2c_chains[idx].probe_dev == IPATH_NO_DEV)
+		idx = -1;
+	else
+		dd->ipath_i2c_chain_type = idx + 1;
+done:
+	return (idx >= 0) ? i2c_chains + idx : NULL;
+}
 
 static int ipath_eeprom_internal_read(struct ipath_devdata *dd,
 					u8 eeprom_offset, void *buffer, int len)
 {
-	/* compiler complains unless initialized */
-	u8 single_byte = 0;
-	int bit_cntr;
 	int ret;
+	struct i2c_chain_desc *icd;
+	u8 *bp = buffer;
 
-	if (!eeprom_init)
-		eeprom_reset(dd);
-
-	eeprom_offset = (eeprom_offset << 1) | READ_CMD;
+	ret = 1;
+	icd = ipath_i2c_type(dd);
+	if (!icd)
+		goto bail;
 
-	if (i2c_startcmd(dd, eeprom_offset)) {
-		ipath_dbg("Failed startcmd\n");
+	if (icd->eeprom_dev == IPATH_NO_DEV) {
+		/* legacy not-really-I2C */
+		ipath_cdbg(VERBOSE, "Start command only address\n");
+		eeprom_offset = (eeprom_offset << 1) | READ_CMD;
+		ret = i2c_startcmd(dd, eeprom_offset);
+	} else {
+		/* Actual I2C */
+		ipath_cdbg(VERBOSE, "Start command uses devaddr\n");
+		if (i2c_startcmd(dd, icd->eeprom_dev | WRITE_CMD)) {
+			ipath_dbg("Failed EEPROM startcmd\n");
+			stop_cmd(dd);
+			ret = 1;
+			goto bail;
+		}
+		ret = wr_byte(dd, eeprom_offset);
+		stop_cmd(dd);
+		if (ret) {
+			ipath_dev_err(dd, "Failed to write EEPROM address\n");
+			ret = 1;
+			goto bail;
+		}
+		ret = i2c_startcmd(dd, icd->eeprom_dev | READ_CMD);
+	}
+	if (ret) {
+		ipath_dbg("Failed startcmd for dev %02X\n", icd->eeprom_dev);
 		stop_cmd(dd);
 		ret = 1;
 		goto bail;
@@ -392,22 +529,11 @@ static int ipath_eeprom_internal_read(struct ipath_devdata *dd,
 	 * incrementing the address.
 	 */
 	while (len-- > 0) {
-		/* get data */
-		single_byte = 0;
-		for (bit_cntr = 8; bit_cntr; bit_cntr--) {
-			u8 bit;
-			scl_out(dd, i2c_line_high);
-			bit = sda_in(dd, 0);
-			single_byte |= bit << (bit_cntr - 1);
-			scl_out(dd, i2c_line_low);
-		}
-
+		/* get and store data */
+		*bp++ = rd_byte(dd);
 		/* send ack if not the last byte */
 		if (len)
 			send_ack(dd);
-
-		*((u8 *) buffer) = single_byte;
-		buffer++;
 	}
 
 	stop_cmd(dd);
@@ -418,31 +544,40 @@ bail:
 	return ret;
 }
 
-
-/**
- * ipath_eeprom_write - writes data to the eeprom via I2C
- * @dd: the infinipath device
- * @eeprom_offset: where to place data
- * @buffer: data to write
- * @len: number of bytes to write
- */
 static int ipath_eeprom_internal_write(struct ipath_devdata *dd, u8 eeprom_offset,
 				       const void *buffer, int len)
 {
-	u8 single_byte;
 	int sub_len;
 	const u8 *bp = buffer;
 	int max_wait_time, i;
 	int ret;
+	struct i2c_chain_desc *icd;
 
-	if (!eeprom_init)
-		eeprom_reset(dd);
+	ret = 1;
+	icd = ipath_i2c_type(dd);
+	if (!icd)
+		goto bail;
 
 	while (len > 0) {
-		if (i2c_startcmd(dd, (eeprom_offset << 1) | WRITE_CMD)) {
-			ipath_dbg("Failed to start cmd offset %u\n",
-				  eeprom_offset);
-			goto failed_write;
+		if (icd->eeprom_dev == IPATH_NO_DEV) {
+			if (i2c_startcmd(dd,
+					 (eeprom_offset << 1) | WRITE_CMD)) {
+				ipath_dbg("Failed to start cmd offset %u\n",
+					eeprom_offset);
+				goto failed_write;
+			}
+		} else {
+			/* Real I2C */
+			if (i2c_startcmd(dd, icd->eeprom_dev | WRITE_CMD)) {
+				ipath_dbg("Failed EEPROM startcmd\n");
+				goto failed_write;
+			}
+			ret = wr_byte(dd, eeprom_offset);
+			if (ret) {
+				ipath_dev_err(dd, "Failed to write EEPROM "
+					      "address\n");
+				goto failed_write;
+			}
 		}
 
 		sub_len = min(len, 4);
@@ -468,9 +603,11 @@ static int ipath_eeprom_internal_write(struct ipath_devdata *dd, u8 eeprom_offse
 		 * the writes have completed.   We do this inline to avoid
 		 * the debug prints that are in the real read routine
 		 * if the startcmd fails.
+		 * We also use the proper device address, so it doesn't matter
+		 * whether we have real eeprom_dev. legacy likes any address.
 		 */
 		max_wait_time = 100;
-		while (i2c_startcmd(dd, READ_CMD)) {
+		while (i2c_startcmd(dd, icd->eeprom_dev | READ_CMD)) {
 			stop_cmd(dd);
 			if (!--max_wait_time) {
 				ipath_dbg("Did not get successful read to "
@@ -478,15 +615,8 @@ static int ipath_eeprom_internal_write(struct ipath_devdata *dd, u8 eeprom_offse
 				goto failed_write;
 			}
 		}
-		/* now read the zero byte */
-		for (i = single_byte = 0; i < 8; i++) {
-			u8 bit;
-			scl_out(dd, i2c_line_high);
-			bit = sda_in(dd, 0);
-			scl_out(dd, i2c_line_low);
-			single_byte <<= 1;
-			single_byte |= bit;
-		}
+		/* now read (and ignore) the resulting byte */
+		rd_byte(dd);
 		stop_cmd(dd);
 	}
 
@@ -501,9 +631,12 @@ bail:
 	return ret;
 }
 
-/*
- * The public entry-points ipath_eeprom_read() and ipath_eeprom_write()
- * are now just wrappers around the internal functions.
+/**
+ * ipath_eeprom_read - receives bytes from the eeprom via I2C
+ * @dd: the infinipath device
+ * @eeprom_offset: address to read from
+ * @buffer: where to store result
+ * @len: number of bytes to receive
  */
 int ipath_eeprom_read(struct ipath_devdata *dd, u8 eeprom_offset,
 			void *buff, int len)
@@ -519,6 +652,13 @@ int ipath_eeprom_read(struct ipath_devdata *dd, u8 eeprom_offset,
 	return ret;
 }
 
+/**
+ * ipath_eeprom_write - writes data to the eeprom via I2C
+ * @dd: the infinipath device
+ * @eeprom_offset: where to place data
+ * @buffer: data to write
+ * @len: number of bytes to write
+ */
 int ipath_eeprom_write(struct ipath_devdata *dd, u8 eeprom_offset,
 			const void *buff, int len)
 {
@@ -820,7 +960,7 @@ int ipath_update_eeprom_log(struct ipath_devdata *dd)
 	 * if we log an hour at 31 minutes, then we would need to set
 	 * active_time to -29 to accurately count the _next_ hour.
 	 */
-	if (new_time > 3600) {
+	if (new_time >= 3600) {
 		new_hrs = new_time / 3600;
 		atomic_sub((new_hrs * 3600), &dd->ipath_active_time);
 		new_hrs += dd->ipath_eep_hrs;
@@ -885,3 +1025,159 @@ void ipath_inc_eeprom_err(struct ipath_devdata *dd, u32 eidx, u32 incr)
 	spin_unlock_irqrestore(&dd->ipath_eep_st_lock, flags);
 	return;
 }
+
+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;
+}