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Wed, 05 Jun 2024 21:23:26 +0000 Received: from smtpav06.dal12v.mail.ibm.com (smtpav06.dal12v.mail.ibm.com [10.241.53.105]) by smtprelay03.wdc07v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 455LNNwB23790302 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 5 Jun 2024 21:23:25 GMT Received: from smtpav06.dal12v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 062A058061; Wed, 5 Jun 2024 21:23:23 +0000 (GMT) Received: from smtpav06.dal12v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B5BBD5806A; Wed, 5 Jun 2024 21:23:22 +0000 (GMT) Received: from slate16.aus.stglabs.ibm.com (unknown [9.61.121.242]) by smtpav06.dal12v.mail.ibm.com (Postfix) with ESMTP; Wed, 5 Jun 2024 21:23:22 +0000 (GMT) From: Eddie James To: linux-fsi@lists.ozlabs.org Cc: eajames@linux.ibm.com, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, linux-spi@vger.kernel.org, broonie@kernel.org, andi.shyti@kernel.org, joel@jms.id.au, alistair@popple.id.au, jk@ozlabs.org, andrew@codeconstruct.com.au, linux-aspeed@lists.ozlabs.org, ninad@linux.ibm.com, lakshmiy@us.ibm.com Subject: [PATCH v4 32/40] i2c: fsi: Add interrupt support Date: Wed, 5 Jun 2024 16:23:04 -0500 Message-Id: <20240605212312.349188-33-eajames@linux.ibm.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20240605212312.349188-1-eajames@linux.ibm.com> References: <20240605212312.349188-1-eajames@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-spi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-GUID: Eze2TnuZ5ZbI2cln7BOhaVQHB_SCg28a X-Proofpoint-ORIG-GUID: Eze2TnuZ5ZbI2cln7BOhaVQHB_SCg28a X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.28.16 definitions=2024-06-05_02,2024-06-05_02,2024-05-17_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 mlxlogscore=999 spamscore=0 phishscore=0 malwarescore=0 mlxscore=0 priorityscore=1501 bulkscore=0 impostorscore=0 clxscore=1015 adultscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2405010000 definitions=main-2406050160 Optionally support interrupts from the I2C controller so that the driver can wait rather than poll the status register. Signed-off-by: Eddie James --- drivers/i2c/busses/i2c-fsi.c | 215 ++++++++++++++++++++++++++++++--- include/trace/events/i2c_fsi.h | 45 +++++++ 2 files changed, 245 insertions(+), 15 deletions(-) create mode 100644 include/trace/events/i2c_fsi.h diff --git a/drivers/i2c/busses/i2c-fsi.c b/drivers/i2c/busses/i2c-fsi.c index 614d830419bb8..f8d9bc178ef5b 100644 --- a/drivers/i2c/busses/i2c-fsi.c +++ b/drivers/i2c/busses/i2c-fsi.c @@ -23,6 +23,7 @@ #include #include #include +#include #define FSI_ENGID_I2C 0x7 @@ -87,6 +88,7 @@ #define I2C_INT_STOP_ERR BIT(7) #define I2C_INT_BUSY BIT(6) #define I2C_INT_IDLE BIT(5) +#define I2C_INT_ANY GENMASK(15, 7) /* status register */ #define I2C_STAT_INV_CMD BIT(31) @@ -148,21 +150,35 @@ /* choose timeout length from legacy driver; it's well tested */ #define I2C_ABORT_TIMEOUT msecs_to_jiffies(100) +struct fsi_i2c_port; + struct fsi_i2c_master { struct fsi_device *fsi; + struct fsi_i2c_port *port; struct mutex lock; + wait_queue_head_t wait; u32 clock_div; u8 fifo_size; + bool interrupts; bool skip_stop; + bool abort; }; struct fsi_i2c_port { struct i2c_adapter adapter; struct fsi_i2c_master *master; + struct i2c_msg *msgs; + int nmsgs; + int rc; + int i; u16 port; u16 xfrd; + bool wake; }; +#define CREATE_TRACE_POINTS +#include + static int fsi_i2c_read_reg(struct fsi_device *fsi, unsigned int reg, u32 *data) { @@ -192,7 +208,7 @@ static int fsi_i2c_dev_init(struct fsi_i2c_master *i2c) u32 watermark; int rc; - /* since we use polling, disable interrupts */ + /* start with interrupts disabled */ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_INT_MASK, 0); if (rc) return rc; @@ -236,22 +252,24 @@ static int fsi_i2c_set_port(struct fsi_i2c_port *port) return fsi_i2c_write_reg(fsi, I2C_FSI_RESET_ERR, 0); } -static int fsi_i2c_start(struct fsi_i2c_port *port, struct i2c_msg *msg, - bool stop) +static int fsi_i2c_start(struct fsi_i2c_port *port) { u32 cmd = I2C_CMD_WITH_START | I2C_CMD_WITH_ADDR; + struct i2c_msg *msg = &port->msgs[port->i]; port->xfrd = 0; if (msg->flags & I2C_M_RD) cmd |= I2C_CMD_READ; - if (stop || msg->flags & I2C_M_STOP) + if ((port->i == (port->nmsgs - 1)) || (msg->flags & I2C_M_STOP)) cmd |= I2C_CMD_WITH_STOP; cmd |= FIELD_PREP(I2C_CMD_ADDR, msg->addr); cmd |= FIELD_PREP(I2C_CMD_LEN, msg->len); + trace_i2c_fsi_start(port, cmd); + return fsi_i2c_write_reg(port->master->fsi, I2C_FSI_CMD, cmd); } @@ -489,11 +507,38 @@ static int fsi_i2c_abort(struct fsi_i2c_port *port) if (i2c->skip_stop) return 0; + if (i2c->interrupts) { + i2c->abort = true; + port->wake = false; + + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_INT_MASK, I2C_INT_ANY); + if (rc) + return rc; + } + /* write stop command */ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_CMD, cmd); if (rc) return rc; + if (i2c->interrupts) { + rc = wait_event_interruptible_timeout(i2c->wait, port->wake, I2C_ABORT_TIMEOUT); + if (rc > 0) + return port->rc; + + fsi_i2c_write_reg(i2c->fsi, I2C_FSI_INT_MASK, 0); + + if (!rc) { + rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_STAT, &status); + if (!rc && (status & I2C_STAT_CMD_COMP)) + rc = 0; + else + rc = -ETIMEDOUT; + } + + return rc; + } + /* wait until we see command complete in the master */ start = jiffies; do { @@ -564,8 +609,59 @@ static int fsi_i2c_handle_status(struct fsi_i2c_port *port, return 0; } -static int fsi_i2c_wait(struct fsi_i2c_port *port, struct i2c_msg *msg, - unsigned long timeout) +static int fsi_i2c_wait_irq(struct fsi_i2c_port *port, unsigned long timeout) +{ + int rc; + + port->wake = false; + + rc = fsi_i2c_write_reg(port->master->fsi, I2C_FSI_INT_MASK, I2C_INT_ANY); + if (rc) + return rc; + + rc = wait_event_interruptible_timeout(port->master->wait, port->wake, timeout); + if (rc > 0) { + rc = port->rc; + + if (port->master->abort) { + int rc2 = fsi_i2c_abort(port); + + if (rc2) + return rc2; + } + + return rc; + } + + /* + * The interrupt handler should turn off interrupts once it's done, but in this + * case we timed out or were interrupted, so mask them off here. + */ + fsi_i2c_write_reg(port->master->fsi, I2C_FSI_INT_MASK, 0); + + if (!rc) { + u32 status; + + rc = fsi_i2c_read_reg(port->master->fsi, I2C_FSI_STAT, &status); + if (!rc && (status & I2C_STAT_ANY_RESP)) { + rc = fsi_i2c_handle_status(port, &port->msgs[port->i], status); + if (rc < 0) + return rc; + + /* cmd complete and all data xfrd */ + if (rc == port->msgs[port->i].len) + return 0; + + rc = -ETIMEDOUT; + } else { + rc = -ETIMEDOUT; + } + } + + return rc; +} + +static int fsi_i2c_wait_poll(struct fsi_i2c_port *port, unsigned long timeout) { unsigned long start = jiffies; u32 status; @@ -578,12 +674,12 @@ static int fsi_i2c_wait(struct fsi_i2c_port *port, struct i2c_msg *msg, return rc; if (status & I2C_STAT_ANY_RESP) { - rc = fsi_i2c_handle_status(port, msg, status); + rc = fsi_i2c_handle_status(port, &port->msgs[port->i], status); if (rc < 0) return rc; /* cmd complete and all data xfrd */ - if (rc == msg->len) + if (rc == port->msgs[port->i].len) return 0; /* need to xfr more data, but maybe don't need wait */ @@ -601,9 +697,7 @@ static int fsi_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, { struct fsi_i2c_port *port = i2c_get_adapdata(adap); unsigned long start_time; - struct i2c_msg *msg; int rc; - int i; mutex_lock(&port->master->lock); @@ -611,21 +705,28 @@ static int fsi_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, if (rc) goto unlock; - for (i = 0; i < num; i++) { - msg = msgs + i; + port->master->port = port; + port->master->abort = false; + port->msgs = msgs; + port->nmsgs = num; + for (port->i = 0; port->i < num; ++port->i) { start_time = jiffies; - rc = fsi_i2c_start(port, msg, i == num - 1); + rc = fsi_i2c_start(port); if (rc) goto unlock; - rc = fsi_i2c_wait(port, msg, - adap->timeout - (jiffies - start_time)); + if (port->master->interrupts) + rc = fsi_i2c_wait_irq(port, adap->timeout - (jiffies - start_time)); + else + rc = fsi_i2c_wait_poll(port, adap->timeout - (jiffies - start_time)); if (rc) goto unlock; } unlock: + port->msgs = NULL; + port->master->port = NULL; mutex_unlock(&port->master->lock); return rc ? : num; } @@ -636,6 +737,85 @@ static u32 fsi_i2c_functionality(struct i2c_adapter *adap) I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA; } +static irqreturn_t fsi_i2c_irq(int irq, void *data) +{ + struct fsi_i2c_master *i2c = data; + struct fsi_i2c_port *port; + struct i2c_msg *msg; + u32 status; + int rc; + + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_INT_MASK, 0); + if (rc) + return IRQ_NONE; + + if (!i2c->port) + return IRQ_HANDLED; + + port = i2c->port; + rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_STAT, &status); + if (rc) + goto wake; + + trace_i2c_fsi_irq(port, status); + + if (i2c->abort) { + if (status & I2C_STAT_CMD_COMP) { + port->wake = true; + goto done; + } else { + rc = fsi_i2c_error_status_to_rc(status); + goto wake; + } + } + + if (status & I2C_STAT_ERR) { + i2c->abort = true; + i2c->skip_stop = status & I2C_STAT_SKIP_STOP; + rc = fsi_i2c_error_status_to_rc(status); + goto wake; + } + + if (!port->msgs || port->i >= port->nmsgs) { + rc = -ENODEV; + goto wake; + } + + msg = &port->msgs[port->i]; + if (status & I2C_STAT_DAT_REQ) { + u8 fifo_count = FIELD_GET(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); + } else if (status & I2C_STAT_CMD_COMP) { + if (port->xfrd < msg->len) { + rc = -ENODATA; + } else { + ++port->i; + if (port->i < port->nmsgs) { + rc = fsi_i2c_start(port); + } else { + port->wake = true; + goto done; + } + } + } + + if (!rc) + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_INT_MASK, I2C_INT_ANY); + +wake: + if (rc) + port->wake = true; +done: + port->rc = rc; + if (port->wake) + wake_up_interruptible_all(&i2c->wait); + return IRQ_HANDLED; +} + static struct i2c_bus_recovery_info fsi_i2c_bus_recovery_info = { .recover_bus = i2c_generic_scl_recovery, .get_scl = fsi_i2c_get_scl, @@ -683,6 +863,7 @@ static int fsi_i2c_probe(struct device *dev) return -ENOMEM; mutex_init(&i2c->lock); + init_waitqueue_head(&i2c->wait); i2c->fsi = to_fsi_dev(dev); i2c->clock_div = I2C_DEFAULT_CLK_DIV; @@ -706,6 +887,10 @@ static int fsi_i2c_probe(struct device *dev) if (rc) return rc; + rc = fsi_device_request_irq(i2c->fsi, fsi_i2c_irq, i2c); + if (!rc) + i2c->interrupts = true; + ports = FIELD_GET(I2C_STAT_MAX_PORT, stat) + 1; dev_dbg(dev, "I2C master has %d ports\n", ports); diff --git a/include/trace/events/i2c_fsi.h b/include/trace/events/i2c_fsi.h new file mode 100644 index 0000000000000..ac49ae9be356b --- /dev/null +++ b/include/trace/events/i2c_fsi.h @@ -0,0 +1,45 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#undef TRACE_SYSTEM +#define TRACE_SYSTEM i2c_fsi + +#if !defined(_TRACE_I2C_FSI_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_I2C_FSI_H + +#include + +TRACE_EVENT(i2c_fsi_irq, + TP_PROTO(const struct fsi_i2c_port *port, uint32_t status), + TP_ARGS(port, status), + TP_STRUCT__entry( + __field(int, bus) + __field(int, msg_idx) + __field(uint32_t, status) + ), + TP_fast_assign( + __entry->bus = port->adapter.nr; + __entry->msg_idx = port->i; + __entry->status = status; + ), + TP_printk("i2c-%d [%d] status:%08x", __entry->bus, __entry->msg_idx, __entry->status) +); + +TRACE_EVENT(i2c_fsi_start, + TP_PROTO(const struct fsi_i2c_port *port, uint32_t command), + TP_ARGS(port, command), + TP_STRUCT__entry( + __field(int, bus) + __field(int, msg_idx) + __field(uint32_t, command) + ), + TP_fast_assign( + __entry->bus = port->adapter.nr; + __entry->msg_idx = port->i; + __entry->command = command; + ), + TP_printk("i2c-%d [%d] command:%08x", __entry->bus, __entry->msg_idx, __entry->command) +); + +#endif + +#include