From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751716AbeFDVMM (ORCPT ); Mon, 4 Jun 2018 17:12:12 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:40270 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751282AbeFDVMK (ORCPT ); Mon, 4 Jun 2018 17:12:10 -0400 Subject: Re: [PATCH v9 5/7] i2c: fsi: Add transfer implementation To: Peter Rosin , linux-i2c@vger.kernel.org Cc: linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, wsa@the-dreams.de, robh+dt@kernel.org, benh@kernel.crashing.org, joel@jms.id.au, mark.rutland@arm.com, gregkh@linuxfoundation.org, rdunlap@infradead.org, andy.shevchenko@gmail.com References: <1528138850-18259-1-git-send-email-eajames@linux.vnet.ibm.com> <1528138850-18259-6-git-send-email-eajames@linux.vnet.ibm.com> <92b61473-b5bb-ea2e-56ce-5375641c5242@axentia.se> From: Eddie James Date: Mon, 4 Jun 2018 16:12:01 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <92b61473-b5bb-ea2e-56ce-5375641c5242@axentia.se> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-TM-AS-GCONF: 00 x-cbid: 18060421-0064-0000-0000-0000031523DD X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009130; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000265; SDB=6.01042345; UDB=6.00533734; IPR=6.00821476; MB=3.00021461; MTD=3.00000008; XFM=3.00000015; UTC=2018-06-04 21:12:07 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18060421-0065-0000-0000-0000397AAAD6 Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-06-04_14:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1805220000 definitions=main-1806040241 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/04/2018 02:45 PM, Peter Rosin wrote: > On 2018-06-04 21:00, Eddie James wrote: >> Execute I2C transfers from the FSI-attached I2C master. Use polling >> instead of interrupts as we have no hardware IRQ over FSI. >> >> Signed-off-by: Eddie James >> --- >> drivers/i2c/busses/i2c-fsi.c | 195 ++++++++++++++++++++++++++++++++++++++++++- >> 1 file changed, 193 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/i2c/busses/i2c-fsi.c b/drivers/i2c/busses/i2c-fsi.c >> index 101b9c5..4e5964e 100644 >> --- a/drivers/i2c/busses/i2c-fsi.c >> +++ b/drivers/i2c/busses/i2c-fsi.c >> @@ -150,6 +150,7 @@ struct fsi_i2c_port { >> struct i2c_adapter adapter; >> struct fsi_i2c_master *master; >> u16 port; >> + u16 xfrd; >> }; >> >> static int fsi_i2c_read_reg(struct fsi_device *fsi, unsigned int reg, >> @@ -225,6 +226,99 @@ static int fsi_i2c_set_port(struct fsi_i2c_port *port) >> return fsi_i2c_write_reg(fsi, I2C_FSI_RESET_ERR, &dummy); >> } >> >> +static int fsi_i2c_start(struct fsi_i2c_port *port, struct i2c_msg *msg, >> + bool stop) >> +{ >> + struct fsi_i2c_master *i2c = port->master; >> + u32 cmd = I2C_CMD_WITH_START | I2C_CMD_WITH_ADDR; >> + >> + port->xfrd = 0; >> + >> + if (msg->flags & I2C_M_RD) >> + cmd |= I2C_CMD_READ; >> + >> + if (stop || msg->flags & I2C_M_STOP) >> + cmd |= I2C_CMD_WITH_STOP; >> + >> + cmd |= FIELD_PREP(I2C_CMD_ADDR, msg->addr >> 1); >> + cmd |= FIELD_PREP(I2C_CMD_LEN, msg->len); >> + >> + return fsi_i2c_write_reg(i2c->fsi, I2C_FSI_CMD, &cmd); >> +} >> + >> +static int fsi_i2c_get_op_bytes(int op_bytes) >> +{ >> + /* fsi is limited to max 4 byte aligned ops */ >> + if (op_bytes > 4) >> + return 4; >> + else if (op_bytes == 3) >> + return 2; >> + return op_bytes; >> +} >> + >> +static int fsi_i2c_write_fifo(struct fsi_i2c_port *port, struct i2c_msg *msg, >> + u8 fifo_count) >> +{ >> + int write; >> + int rc; >> + struct fsi_i2c_master *i2c = port->master; >> + int bytes_to_write = i2c->fifo_size - fifo_count; >> + int bytes_remaining = msg->len - port->xfrd; >> + >> + bytes_to_write = min(bytes_to_write, bytes_remaining); >> + >> + while (bytes_to_write) { >> + write = fsi_i2c_get_op_bytes(bytes_to_write); >> + >> + rc = fsi_device_write(i2c->fsi, I2C_FSI_FIFO, >> + &msg->buf[port->xfrd], write); >> + if (rc) >> + return rc; >> + >> + port->xfrd += write; >> + bytes_to_write -= write; >> + } >> + >> + return 0; >> +} >> + >> +static int fsi_i2c_read_fifo(struct fsi_i2c_port *port, struct i2c_msg *msg, >> + u8 fifo_count) >> +{ >> + int read; >> + int rc; >> + struct fsi_i2c_master *i2c = port->master; >> + int bytes_to_read; >> + int xfr_remaining = msg->len - port->xfrd; >> + u32 dummy; >> + >> + bytes_to_read = min_t(int, fifo_count, xfr_remaining); >> + >> + while (bytes_to_read) { >> + read = fsi_i2c_get_op_bytes(bytes_to_read); >> + >> + if (xfr_remaining) { >> + rc = fsi_device_read(i2c->fsi, I2C_FSI_FIFO, >> + &msg->buf[port->xfrd], read); >> + if (rc) >> + return rc; >> + >> + port->xfrd += read; >> + xfr_remaining -= read; >> + } else { >> + /* no more buffer but data in fifo, need to clear it */ >> + rc = fsi_device_read(i2c->fsi, I2C_FSI_FIFO, &dummy, >> + read); >> + if (rc) >> + return rc; >> + } >> + >> + bytes_to_read -= read; >> + } >> + >> + return 0; >> +} >> + >> static int fsi_i2c_reset_bus(struct fsi_i2c_master *i2c) >> { >> int i, rc; >> @@ -388,17 +482,114 @@ static int fsi_i2c_abort(struct fsi_i2c_port *port, u32 status) >> return -ETIMEDOUT; >> } >> >> +static int fsi_i2c_handle_status(struct fsi_i2c_port *port, >> + struct i2c_msg *msg, u32 status) >> +{ >> + int rc; >> + u8 fifo_count; >> + >> + if (status & I2C_STAT_ERR) { >> + rc = fsi_i2c_abort(port, status); >> + if (rc) >> + return rc; >> + >> + if (status & I2C_STAT_INV_CMD) >> + return -EINVAL; >> + >> + if (status & (I2C_STAT_PARITY | I2C_STAT_BE_OVERRUN | >> + I2C_STAT_BE_ACCESS)) >> + return -EPROTO; >> + >> + if (status & I2C_STAT_NACK) >> + return -ENXIO; >> + >> + if (status & I2C_STAT_LOST_ARB) >> + return -EAGAIN; >> + >> + if (status & I2C_STAT_STOP_ERR) >> + return -EBADMSG; >> + >> + return -EIO; >> + } >> + >> + if (status & I2C_STAT_DAT_REQ) { >> + fifo_count = FIELD_GET(I2C_STAT_FIFO_COUNT, status); >> + >> + if (msg->flags & I2C_M_RD) >> + return fsi_i2c_read_fifo(port, msg, fifo_count); >> + >> + return fsi_i2c_write_fifo(port, msg, fifo_count); >> + } >> + >> + if (status & I2C_STAT_CMD_COMP) { >> + if (port->xfrd < msg->len) >> + return -ENODATA; >> + >> + return msg->len; >> + } >> + >> + return 0; >> +} >> + >> +static int fsi_i2c_wait(struct fsi_i2c_port *port, struct i2c_msg *msg, >> + unsigned long timeout) >> +{ >> + u32 status = 0; >> + int rc; >> + unsigned long start = jiffies; >> + >> + do { >> + rc = fsi_i2c_read_reg(port->master->fsi, I2C_FSI_STAT, >> + &status); >> + if (rc) >> + return rc; >> + >> + if (status & I2C_STAT_ANY_RESP) { >> + rc = fsi_i2c_handle_status(port, msg, status); >> + if (rc < 0) >> + return rc; >> + >> + /* cmd complete and all data xfrd */ >> + if (rc == msg->len) >> + return 0; >> + >> + /* need to xfr more data, but maybe don't need wait */ >> + continue; >> + } >> + >> + usleep_range(I2C_CMD_SLEEP_MIN_US, I2C_CMD_SLEEP_MAX_US); >> + } while (time_after(start + timeout, jiffies)); >> + >> + return -ETIMEDOUT; >> +} >> + >> static int fsi_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, >> int num) >> { >> - int rc; >> + int i, rc; >> + unsigned long start_time; >> struct fsi_i2c_port *port = adap->algo_data; >> + struct i2c_msg *msg; >> >> rc = fsi_i2c_set_port(port); >> if (rc) >> return rc; >> >> - return -EOPNOTSUPP; >> + for (i = 0; i < num; i++) { >> + msg = msgs + i; >> + start_time = jiffies; >> + >> + rc = fsi_i2c_start(port, msg, i == num - 1); >> + if (rc) >> + return rc; >> + >> + rc = fsi_i2c_wait(port, msg, >> + adap->timeout - (jiffies - start_time)); >> + if (rc) >> + return rc; >> + } >> + >> + return 0; > Zero is not the return value of success for .master_xfer > > Hint, "num" is your friend... > > Cheers, > Peter Good catch, I'll fix that. Thanks, Eddie > >> } >> >> static u32 fsi_i2c_functionality(struct i2c_adapter *adap) >>