From f1bf29634057f56507945589aa40c96c649073ee Mon Sep 17 00:00:00 2001 From: Dean Luick Date: Wed, 3 Feb 2016 14:34:15 -0800 Subject: [PATCH] staging/rdma/hfi1: Fix for generic I2C interface The original I2C interface was geared for QSFP accesses. Modify the interface to behave more like a generic I2C controller such that reads and writes can accept multi-byte offsets. Removed reads following writes and moved reset to top level. Reviewed-by: Easwar Hariharan Reviewed-by: Dean Luick Signed-off-by: Pablo Cacho Signed-off-by: Jubin John Signed-off-by: Doug Ledford --- drivers/staging/rdma/hfi1/debugfs.c | 6 +- drivers/staging/rdma/hfi1/qsfp.c | 88 +++++++++++------- drivers/staging/rdma/hfi1/qsfp.h | 4 + drivers/staging/rdma/hfi1/twsi.c | 134 ++++++++++++---------------- 4 files changed, 122 insertions(+), 110 deletions(-) diff --git a/drivers/staging/rdma/hfi1/debugfs.c b/drivers/staging/rdma/hfi1/debugfs.c index acd2269e9f14..d6dc339fb2a3 100644 --- a/drivers/staging/rdma/hfi1/debugfs.c +++ b/drivers/staging/rdma/hfi1/debugfs.c @@ -463,7 +463,8 @@ static ssize_t __i2c_debugfs_write(struct file *file, const char __user *buf, goto _free; } - i2c_addr = (*ppos >> 16) & 0xff; + /* byte offset format: [offsetSize][i2cAddr][offsetHigh][offsetLow] */ + i2c_addr = (*ppos >> 16) & 0xffff; offset = *ppos & 0xffff; total_written = i2c_write(ppd, target, i2c_addr, offset, buff, count); @@ -517,7 +518,8 @@ static ssize_t __i2c_debugfs_read(struct file *file, char __user *buf, goto _return; } - i2c_addr = (*ppos >> 16) & 0xff; + /* byte offset format: [offsetSize][i2cAddr][offsetHigh][offsetLow] */ + i2c_addr = (*ppos >> 16) & 0xffff; offset = *ppos & 0xffff; total_read = i2c_read(ppd, target, i2c_addr, offset, buff, count); diff --git a/drivers/staging/rdma/hfi1/qsfp.c b/drivers/staging/rdma/hfi1/qsfp.c index 0d2ec972ea9f..0e1a49294d99 100644 --- a/drivers/staging/rdma/hfi1/qsfp.c +++ b/drivers/staging/rdma/hfi1/qsfp.c @@ -71,14 +71,6 @@ static int __i2c_write(struct hfi1_pportdata *ppd, u32 target, int i2c_addr, int ret, cnt; u8 *buff = bp; - /* Make sure TWSI bus is in sane state. */ - ret = hfi1_twsi_reset(dd, target); - if (ret) { - hfi1_dev_porterr(dd, ppd->port, - "I2C interface Reset for write failed\n"); - return -EIO; - } - cnt = 0; while (cnt < len) { int wlen = len - cnt; @@ -106,11 +98,22 @@ int i2c_write(struct hfi1_pportdata *ppd, u32 target, int i2c_addr, int offset, int ret; ret = mutex_lock_interruptible(&dd->qsfp_i2c_mutex); - if (!ret) { - ret = __i2c_write(ppd, target, i2c_addr, offset, bp, len); - mutex_unlock(&dd->qsfp_i2c_mutex); + if (ret) + return ret; + + /* make sure the TWSI bus is in a sane state */ + ret = hfi1_twsi_reset(ppd->dd, target); + if (ret) { + hfi1_dev_porterr(ppd->dd, ppd->port, + "I2C write interface reset failed\n"); + ret = -EIO; + goto done; } + ret = __i2c_write(ppd, target, i2c_addr, offset, bp, len); + +done: + mutex_unlock(&dd->qsfp_i2c_mutex); return ret; } @@ -125,16 +128,6 @@ static int __i2c_read(struct hfi1_pportdata *ppd, u32 target, int i2c_addr, int stuck = 0; u8 *buff = bp; - /* Make sure TWSI bus is in sane state. */ - ret = hfi1_twsi_reset(dd, target); - if (ret) { - hfi1_dev_porterr(dd, ppd->port, - "I2C interface Reset for read failed\n"); - ret = -EIO; - stuck = 1; - goto exit; - } - cnt = 0; while (cnt < len) { int rlen = len - cnt; @@ -178,11 +171,22 @@ int i2c_read(struct hfi1_pportdata *ppd, u32 target, int i2c_addr, int offset, int ret; ret = mutex_lock_interruptible(&dd->qsfp_i2c_mutex); - if (!ret) { - ret = __i2c_read(ppd, target, i2c_addr, offset, bp, len); - mutex_unlock(&dd->qsfp_i2c_mutex); + if (ret) + return ret; + + /* make sure the TWSI bus is in a sane state */ + ret = hfi1_twsi_reset(ppd->dd, target); + if (ret) { + hfi1_dev_porterr(ppd->dd, ppd->port, + "I2C read interface reset failed\n"); + ret = -EIO; + goto done; } + ret = __i2c_read(ppd, target, i2c_addr, offset, bp, len); + +done: + mutex_unlock(&dd->qsfp_i2c_mutex); return ret; } @@ -203,6 +207,15 @@ int qsfp_write(struct hfi1_pportdata *ppd, u32 target, int addr, void *bp, if (ret) return ret; + /* make sure the TWSI bus is in a sane state */ + ret = hfi1_twsi_reset(ppd->dd, target); + if (ret) { + hfi1_dev_porterr(ppd->dd, ppd->port, + "QSFP write interface reset failed\n"); + mutex_unlock(&ppd->dd->qsfp_i2c_mutex); + return -EIO; + } + while (count < len) { /* * Set the qsfp page based on a zero-based addresss @@ -210,8 +223,8 @@ int qsfp_write(struct hfi1_pportdata *ppd, u32 target, int addr, void *bp, */ page = (u8)(addr / QSFP_PAGESIZE); - ret = __i2c_write(ppd, target, QSFP_DEV, - QSFP_PAGE_SELECT_BYTE_OFFS, &page, 1); + ret = __i2c_write(ppd, target, QSFP_DEV | QSFP_OFFSET_SIZE, + QSFP_PAGE_SELECT_BYTE_OFFS, &page, 1); if (ret != 1) { hfi1_dev_porterr( ppd->dd, @@ -227,8 +240,8 @@ int qsfp_write(struct hfi1_pportdata *ppd, u32 target, int addr, void *bp, if (((addr % QSFP_RW_BOUNDARY) + nwrite) > QSFP_RW_BOUNDARY) nwrite = QSFP_RW_BOUNDARY - (addr % QSFP_RW_BOUNDARY); - ret = __i2c_write(ppd, target, QSFP_DEV, offset, bp + count, - nwrite); + ret = __i2c_write(ppd, target, QSFP_DEV | QSFP_OFFSET_SIZE, + offset, bp + count, nwrite); if (ret <= 0) /* stop on error or nothing written */ break; @@ -260,14 +273,23 @@ int qsfp_read(struct hfi1_pportdata *ppd, u32 target, int addr, void *bp, if (ret) return ret; + /* make sure the TWSI bus is in a sane state */ + ret = hfi1_twsi_reset(ppd->dd, target); + if (ret) { + hfi1_dev_porterr(ppd->dd, ppd->port, + "QSFP read interface reset failed\n"); + mutex_unlock(&ppd->dd->qsfp_i2c_mutex); + return -EIO; + } + while (count < len) { /* * Set the qsfp page based on a zero-based address * and a page size of QSFP_PAGESIZE bytes. */ page = (u8)(addr / QSFP_PAGESIZE); - ret = __i2c_write(ppd, target, QSFP_DEV, - QSFP_PAGE_SELECT_BYTE_OFFS, &page, 1); + ret = __i2c_write(ppd, target, QSFP_DEV | QSFP_OFFSET_SIZE, + QSFP_PAGE_SELECT_BYTE_OFFS, &page, 1); if (ret != 1) { hfi1_dev_porterr( ppd->dd, @@ -283,8 +305,10 @@ int qsfp_read(struct hfi1_pportdata *ppd, u32 target, int addr, void *bp, if (((addr % QSFP_RW_BOUNDARY) + nread) > QSFP_RW_BOUNDARY) nread = QSFP_RW_BOUNDARY - (addr % QSFP_RW_BOUNDARY); - ret = __i2c_read(ppd, target, QSFP_DEV, offset, bp + count, - nread); + /* QSFPs require a 5-10msec delay after write operations */ + mdelay(5); + ret = __i2c_read(ppd, target, QSFP_DEV | QSFP_OFFSET_SIZE, + offset, bp + count, nread); if (ret <= 0) /* stop on error or nothing read */ break; diff --git a/drivers/staging/rdma/hfi1/qsfp.h b/drivers/staging/rdma/hfi1/qsfp.h index b1b9e4a2329f..af59a43b2d5f 100644 --- a/drivers/staging/rdma/hfi1/qsfp.h +++ b/drivers/staging/rdma/hfi1/qsfp.h @@ -70,6 +70,10 @@ /* Reads/writes cannot cross 128 byte boundaries */ #define QSFP_RW_BOUNDARY 128 +/* number of bytes in i2c offset for QSFP devices */ +#define __QSFP_OFFSET_SIZE 1 /* num address bytes */ +#define QSFP_OFFSET_SIZE (__QSFP_OFFSET_SIZE << 8) /* shifted value */ + /* Defined fields that Intel requires of qualified cables */ /* Byte 0 is Identifier, not checked */ /* Byte 1 is reserved "status MSB" */ diff --git a/drivers/staging/rdma/hfi1/twsi.c b/drivers/staging/rdma/hfi1/twsi.c index ea54fd2700ad..7c579b343844 100644 --- a/drivers/staging/rdma/hfi1/twsi.c +++ b/drivers/staging/rdma/hfi1/twsi.c @@ -365,17 +365,25 @@ static int twsi_wr(struct hfi1_devdata *dd, u32 target, int data, int flags) * HFI1_TWSI_NO_DEV and does the correct operation for the legacy part, * which responded to all TWSI device codes, interpreting them as * address within device. On all other devices found on board handled by - * this driver, the device is followed by a one-byte "address" which selects + * this driver, the device is followed by a N-byte "address" which selects * the "register" or "offset" within the device from which data should * be read. */ int hfi1_twsi_blk_rd(struct hfi1_devdata *dd, u32 target, int dev, int addr, void *buffer, int len) { - int ret; u8 *bp = buffer; + int ret = 1; + int i; + int offset_size; + + /* obtain the offset size, strip it from the device address */ + offset_size = (dev >> 8) & 0xff; + dev &= 0xff; - ret = 1; + /* allow at most a 2 byte offset */ + if (offset_size > 2) + goto bail; if (dev == HFI1_TWSI_NO_DEV) { /* legacy not-really-I2C */ @@ -383,34 +391,29 @@ int hfi1_twsi_blk_rd(struct hfi1_devdata *dd, u32 target, int dev, int addr, ret = twsi_wr(dd, target, addr, HFI1_TWSI_START); } else { /* Actual I2C */ - ret = twsi_wr(dd, target, dev | WRITE_CMD, HFI1_TWSI_START); - if (ret) { - stop_cmd(dd, target); - ret = 1; - goto bail; - } - /* - * SFF spec claims we do _not_ stop after the addr - * but simply issue a start with the "read" dev-addr. - * Since we are implicitly waiting for ACK here, - * we need t_buf (nominally 20uSec) before that start, - * and cannot rely on the delay built in to the STOP - */ - ret = twsi_wr(dd, target, addr, 0); - udelay(TWSI_BUF_WAIT_USEC); + if (offset_size) { + ret = twsi_wr(dd, target, + dev | WRITE_CMD, HFI1_TWSI_START); + if (ret) { + stop_cmd(dd, target); + goto bail; + } - if (ret) { - dd_dev_err(dd, - "Failed to write interface read addr %02X\n", - addr); - ret = 1; - goto bail; + for (i = 0; i < offset_size; i++) { + ret = twsi_wr(dd, target, + (addr >> (i * 8)) & 0xff, 0); + udelay(TWSI_BUF_WAIT_USEC); + if (ret) { + dd_dev_err(dd, "Failed to write byte %d of offset 0x%04X\n", + i, addr); + goto bail; + } + } } ret = twsi_wr(dd, target, dev | READ_CMD, HFI1_TWSI_START); } if (ret) { stop_cmd(dd, target); - ret = 1; goto bail; } @@ -442,76 +445,55 @@ bail: * HFI1_TWSI_NO_DEV and does the correct operation for the legacy part, * which responded to all TWSI device codes, interpreting them as * address within device. On all other devices found on board handled by - * this driver, the device is followed by a one-byte "address" which selects + * this driver, the device is followed by a N-byte "address" which selects * the "register" or "offset" within the device to which data should * be written. */ int hfi1_twsi_blk_wr(struct hfi1_devdata *dd, u32 target, int dev, int addr, const void *buffer, int len) { - int sub_len; const u8 *bp = buffer; - int max_wait_time, i; int ret = 1; + int i; + int offset_size; - while (len > 0) { - if (dev == HFI1_TWSI_NO_DEV) { - if (twsi_wr(dd, target, (addr << 1) | WRITE_CMD, - HFI1_TWSI_START)) { - goto failed_write; - } - } else { - /* Real I2C */ - if (twsi_wr(dd, target, - dev | WRITE_CMD, HFI1_TWSI_START)) - goto failed_write; - ret = twsi_wr(dd, target, addr, 0); - if (ret) { - dd_dev_err(dd, - "Failed to write interface write addr %02X\n", - addr); - goto failed_write; - } - } + /* obtain the offset size, strip it from the device address */ + offset_size = (dev >> 8) & 0xff; + dev &= 0xff; - sub_len = min(len, 4); - addr += sub_len; - len -= sub_len; - - for (i = 0; i < sub_len; i++) - if (twsi_wr(dd, target, *bp++, 0)) - goto failed_write; + /* allow at most a 2 byte offset */ + if (offset_size > 2) + goto bail; - stop_cmd(dd, target); + if (dev == HFI1_TWSI_NO_DEV) { + if (twsi_wr(dd, target, (addr << 1) | WRITE_CMD, + HFI1_TWSI_START)) { + goto failed_write; + } + } else { + /* Real I2C */ + if (twsi_wr(dd, target, dev | WRITE_CMD, HFI1_TWSI_START)) + goto failed_write; + } - /* - * Wait for write complete by waiting for a successful - * read (the chip replies with a zero after the write - * cmd completes, and before it writes to the eeprom. - * The startcmd for the read will fail the ack until - * 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 (twsi_wr(dd, target, - dev | READ_CMD, HFI1_TWSI_START)) { - stop_cmd(dd, target); - if (!--max_wait_time) - goto failed_write; + for (i = 0; i < offset_size; i++) { + ret = twsi_wr(dd, target, (addr >> (i * 8)) & 0xff, 0); + udelay(TWSI_BUF_WAIT_USEC); + if (ret) { + dd_dev_err(dd, "Failed to write byte %d of offset 0x%04X\n", + i, addr); + goto bail; } - /* now read (and ignore) the resulting byte */ - rd_byte(dd, target, 1); } + for (i = 0; i < len; i++) + if (twsi_wr(dd, target, *bp++, 0)) + goto failed_write; + ret = 0; - goto bail; failed_write: stop_cmd(dd, target); - ret = 1; bail: return ret; -- 2.20.1