From patchwork Mon Jul 10 18:37:59 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eddie James X-Patchwork-Id: 786316 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3x5vCH0m7wz9s0g for ; Tue, 11 Jul 2017 04:39:55 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932108AbdGJSjn (ORCPT ); Mon, 10 Jul 2017 14:39:43 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:47017 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754328AbdGJSiU (ORCPT ); Mon, 10 Jul 2017 14:38:20 -0400 Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v6AIYI0J123108 for ; Mon, 10 Jul 2017 14:38:19 -0400 Received: from e36.co.us.ibm.com (e36.co.us.ibm.com [32.97.110.154]) by mx0b-001b2d01.pphosted.com with ESMTP id 2bm48yj9vk-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 10 Jul 2017 14:38:19 -0400 Received: from localhost by e36.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 10 Jul 2017 12:38:18 -0600 Received: from b03cxnp08028.gho.boulder.ibm.com (9.17.130.20) by e36.co.us.ibm.com (192.168.1.136) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Mon, 10 Jul 2017 12:38:15 -0600 Received: from b03ledav003.gho.boulder.ibm.com (b03ledav003.gho.boulder.ibm.com [9.17.130.234]) by b03cxnp08028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v6AIcEvQ28704824; Mon, 10 Jul 2017 11:38:14 -0700 Received: from b03ledav003.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id E3D7D6A03B; Mon, 10 Jul 2017 12:38:14 -0600 (MDT) Received: from oc3016140333.ibm.com (unknown [9.41.179.225]) by b03ledav003.gho.boulder.ibm.com (Postfix) with ESMTP id 220CB6A03F; Mon, 10 Jul 2017 12:38:14 -0600 (MDT) From: Eddie James To: linux-kernel@vger.kernel.org Cc: linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, wsa@the-dreams.de, robh+dt@kernel.org, gregkh@linuxfoundation.org, jk@ozlabs.org, joel@jms.id.au, andrew@aj.id.au, eajames@linux.vnet.ibm.com, cbostic@linux.vnet.ibm.com, "Edward A. James" Subject: [PATCH v2 3/6] drivers/i2c: Add transfer implementation for FSI algorithm Date: Mon, 10 Jul 2017 13:37:59 -0500 X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1499711882-12918-1-git-send-email-eajames@linux.vnet.ibm.com> References: <1499711882-12918-1-git-send-email-eajames@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17071018-0020-0000-0000-00000C56D08A X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007344; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000214; SDB=6.00885652; UDB=6.00442009; IPR=6.00665801; BA=6.00005464; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00016161; XFM=3.00000015; UTC=2017-07-10 18:38:17 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17071018-0021-0000-0000-00005D2EDD96 Message-Id: <1499711882-12918-4-git-send-email-eajames@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-07-10_08:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1703280000 definitions=main-1707100327 Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org From: "Edward A. James" 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: Edward A. James --- drivers/i2c/busses/i2c-fsi.c | 197 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 195 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-fsi.c b/drivers/i2c/busses/i2c-fsi.c index 4b52147..f86595b 100644 --- a/drivers/i2c/busses/i2c-fsi.c +++ b/drivers/i2c/busses/i2c-fsi.c @@ -13,10 +13,12 @@ #include #include #include +#include #include #include #include #include +#include #define FSI_ENGID_I2C 0x7 @@ -140,6 +142,7 @@ 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, @@ -224,17 +227,207 @@ static int fsi_i2c_set_port(struct fsi_i2c_port *port) return rc; } +static int fsi_i2c_start(struct fsi_i2c_port *port, struct i2c_msg *msg, + bool stop) +{ + int rc; + 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 = SETFIELD(I2C_CMD_ADDR, cmd, msg->addr >> 1); + cmd = SETFIELD(I2C_CMD_LEN, cmd, msg->len); + + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_CMD, &cmd); + + return rc; +} + +static int fsi_i2c_write_fifo(struct fsi_i2c_port *port, struct i2c_msg *msg, + u8 fifo_count) +{ + int write; + int rc = 0; + struct fsi_i2c_master *i2c = port->master; + int bytes_to_write = i2c->fifo_size - fifo_count; + int bytes_remaining = msg->len - port->xfrd; + + if (bytes_to_write > bytes_remaining) + bytes_to_write = bytes_remaining; + + while (bytes_to_write > 0) { + write = bytes_to_write; + /* fsi limited to max 4 byte aligned ops */ + if (bytes_to_write > 4) + write = 4; + else if (write == 3) + write = 2; + + 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 rc; +} + +static int fsi_i2c_read_fifo(struct fsi_i2c_port *port, struct i2c_msg *msg, + u8 fifo_count) +{ + int read; + int rc = 0; + struct fsi_i2c_master *i2c = port->master; + int xfr_remaining = msg->len - port->xfrd; + u32 dummy; + + while (fifo_count) { + read = fifo_count; + /* fsi limited to max 4 byte aligned ops */ + if (fifo_count > 4) + read = 4; + else if (read == 3) + read = 2; + + if (xfr_remaining) { + if (xfr_remaining < read) + read = 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; + } + + fifo_count -= read; + } + + return rc; +} + +static int fsi_i2c_handle_status(struct fsi_i2c_port *port, + struct i2c_msg *msg, u32 status) +{ + int rc; + u8 fifo_count; + struct fsi_i2c_master *i2c = port->master; + u32 dummy = 0; + + if (status & I2C_STAT_ERR) { + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_ERR, &dummy); + if (rc) + return rc; + + if (status & I2C_STAT_NACK) + return -EFAULT; + + return -EIO; + } + + if (status & I2C_STAT_DAT_REQ) { + fifo_count = GETFIELD(I2C_STAT_FIFO_COUNT, status); + + if (msg->flags & I2C_M_RD) + rc = fsi_i2c_read_fifo(port, msg, fifo_count); + else + rc = fsi_i2c_write_fifo(port, msg, fifo_count); + + return rc; + } + + if (status & I2C_STAT_CMD_COMP) { + if (port->xfrd < msg->len) + rc = -ENODATA; + else + rc = msg->len; + + return rc; + } + + return 0; +} + +static int fsi_i2c_wait(struct fsi_i2c_port *port, struct i2c_msg *msg, + unsigned long timeout) +{ + const unsigned long local_timeout = 2; /* jiffies */ + u32 status = 0; + int rc; + + 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; + } + + set_current_state(TASK_UNINTERRUPTIBLE); + schedule_timeout(local_timeout); + timeout = (timeout < local_timeout) ? 0 : + timeout - local_timeout; + } while (timeout); + + return -ETIME; +} + 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; } static u32 fsi_i2c_functionality(struct i2c_adapter *adap)