diff options
Diffstat (limited to 'drivers/infiniband/hw/hfi1/twsi.c')
| -rw-r--r-- | drivers/infiniband/hw/hfi1/twsi.c | 489 |
1 files changed, 0 insertions, 489 deletions
diff --git a/drivers/infiniband/hw/hfi1/twsi.c b/drivers/infiniband/hw/hfi1/twsi.c deleted file mode 100644 index e82e52a63d35..000000000000 --- a/drivers/infiniband/hw/hfi1/twsi.c +++ /dev/null @@ -1,489 +0,0 @@ -/* - * Copyright(c) 2015, 2016 Intel Corporation. - * - * This file is provided under a dual BSD/GPLv2 license. When using or - * redistributing this file, you may do so under either license. - * - * GPL LICENSE SUMMARY - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of version 2 of the GNU General Public License 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. - * - * BSD LICENSE - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * - * - Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * - Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in - * the documentation and/or other materials provided with the - * distribution. - * - Neither the name of Intel Corporation nor the names of its - * contributors may be used to endorse or promote products derived - * from this software without specific prior written permission. - * - * 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. - * - */ - -#include <linux/delay.h> -#include <linux/pci.h> -#include <linux/vmalloc.h> - -#include "hfi.h" -#include "twsi.h" - -/* - * "Two Wire Serial Interface" support. - * - * Originally written for a not-quite-i2c serial eeprom, which is - * still used on some supported boards. Later boards have added a - * variety of other uses, most board-specific, so the bit-boffing - * part has been split off to this file, while the other parts - * have been moved to chip-specific files. - * - * We have also dropped all pretense of fully generic (e.g. pretend - * we don't know whether '1' is the higher voltage) interface, as - * the restrictions of the generic i2c interface (e.g. no access from - * driver itself) make it unsuitable for this use. - */ - -#define READ_CMD 1 -#define WRITE_CMD 0 - -/** - * i2c_wait_for_writes - wait for a write - * @dd: the hfi1_ib device - * - * We use this instead of udelay directly, so we can make sure - * that previous register writes have been flushed all the way - * to the chip. Since we are delaying anyway, the cost doesn't - * hurt, and makes the bit twiddling more regular - */ -static void i2c_wait_for_writes(struct hfi1_devdata *dd, u32 target) -{ - /* - * implicit read of EXTStatus is as good as explicit - * read of scratch, if all we want to do is flush - * writes. - */ - hfi1_gpio_mod(dd, target, 0, 0, 0); - rmb(); /* inlined, so prevent compiler reordering */ -} - -/* - * QSFP modules are allowed to hold SCL low for 500uSec. Allow twice that - * for "almost compliant" modules - */ -#define SCL_WAIT_USEC 1000 - -/* BUF_WAIT is time bus must be free between STOP or ACK and to next START. - * Should be 20, but some chips need more. - */ -#define TWSI_BUF_WAIT_USEC 60 - -static void scl_out(struct hfi1_devdata *dd, u32 target, u8 bit) -{ - u32 mask; - - udelay(1); - - mask = QSFP_HFI0_I2CCLK; - - /* SCL is meant to be bare-drain, so never set "OUT", just DIR */ - hfi1_gpio_mod(dd, target, 0, bit ? 0 : mask, mask); - - /* - * Allow for slow slaves by simple - * delay for falling edge, sampling on rise. - */ - if (!bit) { - udelay(2); - } else { - int rise_usec; - - for (rise_usec = SCL_WAIT_USEC; rise_usec > 0; rise_usec -= 2) { - if (mask & hfi1_gpio_mod(dd, target, 0, 0, 0)) - break; - udelay(2); - } - if (rise_usec <= 0) - dd_dev_err(dd, "SCL interface stuck low > %d uSec\n", - SCL_WAIT_USEC); - } - i2c_wait_for_writes(dd, target); -} - -static u8 scl_in(struct hfi1_devdata *dd, u32 target, int wait) -{ - u32 read_val, mask; - - mask = QSFP_HFI0_I2CCLK; - /* SCL is meant to be bare-drain, so never set "OUT", just DIR */ - hfi1_gpio_mod(dd, target, 0, 0, mask); - read_val = hfi1_gpio_mod(dd, target, 0, 0, 0); - if (wait) - i2c_wait_for_writes(dd, target); - return (read_val & mask) >> GPIO_SCL_NUM; -} - -static void sda_out(struct hfi1_devdata *dd, u32 target, u8 bit) -{ - u32 mask; - - mask = QSFP_HFI0_I2CDAT; - - /* SDA is meant to be bare-drain, so never set "OUT", just DIR */ - hfi1_gpio_mod(dd, target, 0, bit ? 0 : mask, mask); - - i2c_wait_for_writes(dd, target); - udelay(2); -} - -static u8 sda_in(struct hfi1_devdata *dd, u32 target, int wait) -{ - u32 read_val, mask; - - mask = QSFP_HFI0_I2CDAT; - /* SDA is meant to be bare-drain, so never set "OUT", just DIR */ - hfi1_gpio_mod(dd, target, 0, 0, mask); - read_val = hfi1_gpio_mod(dd, target, 0, 0, 0); - if (wait) - i2c_wait_for_writes(dd, target); - return (read_val & mask) >> GPIO_SDA_NUM; -} - -/** - * i2c_ackrcv - see if ack following write is true - * @dd: the hfi1_ib device - */ -static int i2c_ackrcv(struct hfi1_devdata *dd, u32 target) -{ - u8 ack_received; - - /* AT ENTRY SCL = LOW */ - /* change direction, ignore data */ - ack_received = sda_in(dd, target, 1); - scl_out(dd, target, 1); - ack_received = sda_in(dd, target, 1) == 0; - scl_out(dd, target, 0); - return ack_received; -} - -static void stop_cmd(struct hfi1_devdata *dd, u32 target); - -/** - * rd_byte - read a byte, sending STOP on last, else ACK - * @dd: the hfi1_ib device - * - * Returns byte shifted out of device - */ -static int rd_byte(struct hfi1_devdata *dd, u32 target, int last) -{ - int bit_cntr, data; - - data = 0; - - for (bit_cntr = 7; bit_cntr >= 0; --bit_cntr) { - data <<= 1; - scl_out(dd, target, 1); - data |= sda_in(dd, target, 0); - scl_out(dd, target, 0); - } - if (last) { - scl_out(dd, target, 1); - stop_cmd(dd, target); - } else { - sda_out(dd, target, 0); - scl_out(dd, target, 1); - scl_out(dd, target, 0); - sda_out(dd, target, 1); - } - return data; -} - -/** - * wr_byte - write a byte, one bit at a time - * @dd: the hfi1_ib device - * @data: the byte to write - * - * Returns 0 if we got the following ack, otherwise 1 - */ -static int wr_byte(struct hfi1_devdata *dd, u32 target, u8 data) -{ - int bit_cntr; - u8 bit; - - for (bit_cntr = 7; bit_cntr >= 0; bit_cntr--) { - bit = (data >> bit_cntr) & 1; - sda_out(dd, target, bit); - scl_out(dd, target, 1); - scl_out(dd, target, 0); - } - return (!i2c_ackrcv(dd, target)) ? 1 : 0; -} - -/* - * issue TWSI start sequence: - * (both clock/data high, clock high, data low while clock is high) - */ -static void start_seq(struct hfi1_devdata *dd, u32 target) -{ - sda_out(dd, target, 1); - scl_out(dd, target, 1); - sda_out(dd, target, 0); - udelay(1); - scl_out(dd, target, 0); -} - -/** - * stop_seq - transmit the stop sequence - * @dd: the hfi1_ib device - * - * (both clock/data low, clock high, data high while clock is high) - */ -static void stop_seq(struct hfi1_devdata *dd, u32 target) -{ - scl_out(dd, target, 0); - sda_out(dd, target, 0); - scl_out(dd, target, 1); - sda_out(dd, target, 1); -} - -/** - * stop_cmd - transmit the stop condition - * @dd: the hfi1_ib device - * - * (both clock/data low, clock high, data high while clock is high) - */ -static void stop_cmd(struct hfi1_devdata *dd, u32 target) -{ - stop_seq(dd, target); - udelay(TWSI_BUF_WAIT_USEC); -} - -/** - * hfi1_twsi_reset - reset I2C communication - * @dd: the hfi1_ib device - * returns 0 if ok, -EIO on error - */ -int hfi1_twsi_reset(struct hfi1_devdata *dd, u32 target) -{ - int clock_cycles_left = 9; - u32 mask; - - /* Both SCL and SDA should be high. If not, there - * is something wrong. - */ - mask = QSFP_HFI0_I2CCLK | QSFP_HFI0_I2CDAT; - - /* - * Force pins to desired innocuous state. - * This is the default power-on state with out=0 and dir=0, - * So tri-stated and should be floating high (barring HW problems) - */ - hfi1_gpio_mod(dd, target, 0, 0, mask); - - /* Check if SCL is low, if it is low then we have a slave device - * misbehaving and there is not much we can do. - */ - if (!scl_in(dd, target, 0)) - return -EIO; - - /* Check if SDA is low, if it is low then we have to clock SDA - * up to 9 times for the device to release the bus - */ - while (clock_cycles_left--) { - if (sda_in(dd, target, 0)) - return 0; - scl_out(dd, target, 0); - scl_out(dd, target, 1); - } - - return -EIO; -} - -#define HFI1_TWSI_START 0x100 -#define HFI1_TWSI_STOP 0x200 - -/* Write byte to TWSI, optionally prefixed with START or suffixed with - * STOP. - * returns 0 if OK (ACK received), else != 0 - */ -static int twsi_wr(struct hfi1_devdata *dd, u32 target, int data, int flags) -{ - int ret = 1; - - if (flags & HFI1_TWSI_START) - start_seq(dd, target); - - /* Leaves SCL low (from i2c_ackrcv()) */ - ret = wr_byte(dd, target, data); - - if (flags & HFI1_TWSI_STOP) - stop_cmd(dd, target); - return ret; -} - -/* Added functionality for IBA7220-based cards */ -#define HFI1_TEMP_DEV 0x98 - -/* - * hfi1_twsi_blk_rd - * General interface for data transfer from twsi devices. - * One vestige of its former role is that it recognizes a device - * 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 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) -{ - 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; - - /* allow at most a 2 byte offset */ - if (offset_size > 2) - goto bail; - - if (dev == HFI1_TWSI_NO_DEV) { - /* legacy not-really-I2C */ - addr = (addr << 1) | READ_CMD; - ret = twsi_wr(dd, target, addr, HFI1_TWSI_START); - } else { - /* Actual I2C */ - if (offset_size) { - ret = twsi_wr(dd, target, - dev | WRITE_CMD, HFI1_TWSI_START); - if (ret) { - stop_cmd(dd, target); - 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); - goto bail; - } - - /* - * block devices keeps clocking data out as long as we ack, - * automatically incrementing the address. Some have "pages" - * whose boundaries will not be crossed, but the handling - * of these is left to the caller, who is in a better - * position to know. - */ - while (len-- > 0) { - /* - * Get and store data, sending ACK if length remaining, - * else STOP - */ - *bp++ = rd_byte(dd, target, !len); - } - - ret = 0; - -bail: - return ret; -} - -/* - * hfi1_twsi_blk_wr - * General interface for data transfer to twsi devices. - * One vestige of its former role is that it recognizes a device - * 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 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) -{ - const 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; - - /* allow at most a 2 byte offset */ - if (offset_size > 2) - goto bail; - - 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; - } - - 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; - } - } - - for (i = 0; i < len; i++) - if (twsi_wr(dd, target, *bp++, 0)) - goto failed_write; - - ret = 0; - -failed_write: - stop_cmd(dd, target); - -bail: - return ret; -} |