diff options
Diffstat (limited to 'drivers/accel/qaic/qaic_timesync.c')
-rw-r--r-- | drivers/accel/qaic/qaic_timesync.c | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/drivers/accel/qaic/qaic_timesync.c b/drivers/accel/qaic/qaic_timesync.c new file mode 100644 index 000000000000..769250272c21 --- /dev/null +++ b/drivers/accel/qaic/qaic_timesync.c @@ -0,0 +1,245 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved. */ + +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/math64.h> +#include <linux/mhi.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/time64.h> +#include <linux/timer.h> + +#include "qaic.h" +#include "qaic_timesync.h" + +#define QTIMER_REG_OFFSET 0xa28 +#define QAIC_TIMESYNC_SIGNATURE 0x55aa +#define QAIC_CONV_QTIMER_TO_US(qtimer) (mul_u64_u32_div(qtimer, 10, 192)) + +static unsigned int timesync_delay_ms = 1000; /* 1 sec default */ +module_param(timesync_delay_ms, uint, 0600); +MODULE_PARM_DESC(timesync_delay_ms, "Delay in ms between two consecutive timesync operations"); + +enum qts_msg_type { + QAIC_TS_SYNC_REQ = 1, + QAIC_TS_ACK_TO_HOST, + QAIC_TS_MSG_TYPE_MAX +}; + +/** + * struct qts_hdr - Timesync message header structure. + * @signature: Unique signature to identify the timesync message. + * @reserved_1: Reserved for future use. + * @reserved_2: Reserved for future use. + * @msg_type: sub-type of the timesync message. + * @reserved_3: Reserved for future use. + */ +struct qts_hdr { + __le16 signature; + __le16 reserved_1; + u8 reserved_2; + u8 msg_type; + __le16 reserved_3; +} __packed; + +/** + * struct qts_timeval - Structure to carry time information. + * @tv_sec: Seconds part of the time. + * @tv_usec: uS (microseconds) part of the time. + */ +struct qts_timeval { + __le64 tv_sec; + __le64 tv_usec; +} __packed; + +/** + * struct qts_host_time_sync_msg_data - Structure to denote the timesync message. + * @header: Header of the timesync message. + * @data: Time information. + */ +struct qts_host_time_sync_msg_data { + struct qts_hdr header; + struct qts_timeval data; +} __packed; + +/** + * struct mqts_dev - MHI QAIC Timesync Control device. + * @qdev: Pointer to the root device struct driven by QAIC driver. + * @mhi_dev: Pointer to associated MHI device. + * @timer: Timer handle used for timesync. + * @qtimer_addr: Device QTimer register pointer. + * @buff_in_use: atomic variable to track if the sync_msg buffer is in use. + * @dev: Device pointer to qdev->pdev->dev stored for easy access. + * @sync_msg: Buffer used to send timesync message over MHI. + */ +struct mqts_dev { + struct qaic_device *qdev; + struct mhi_device *mhi_dev; + struct timer_list timer; + void __iomem *qtimer_addr; + atomic_t buff_in_use; + struct device *dev; + struct qts_host_time_sync_msg_data *sync_msg; +}; + +#ifdef readq +static u64 read_qtimer(const volatile void __iomem *addr) +{ + return readq(addr); +} +#else +static u64 read_qtimer(const volatile void __iomem *addr) +{ + u64 low, high; + + low = readl(addr); + high = readl(addr + sizeof(u32)); + return low | (high << 32); +} +#endif + +static void qaic_timesync_ul_xfer_cb(struct mhi_device *mhi_dev, struct mhi_result *mhi_result) +{ + struct mqts_dev *mqtsdev = dev_get_drvdata(&mhi_dev->dev); + + dev_dbg(mqtsdev->dev, "%s status: %d xfer_len: %zu\n", __func__, + mhi_result->transaction_status, mhi_result->bytes_xferd); + + atomic_set(&mqtsdev->buff_in_use, 0); +} + +static void qaic_timesync_dl_xfer_cb(struct mhi_device *mhi_dev, struct mhi_result *mhi_result) +{ + struct mqts_dev *mqtsdev = dev_get_drvdata(&mhi_dev->dev); + + dev_err(mqtsdev->dev, "%s no data expected on dl channel\n", __func__); +} + +static void qaic_timesync_timer(struct timer_list *t) +{ + struct mqts_dev *mqtsdev = from_timer(mqtsdev, t, timer); + struct qts_host_time_sync_msg_data *sync_msg; + u64 device_qtimer_us; + u64 device_qtimer; + u64 host_time_us; + u64 offset_us; + u64 host_sec; + int ret; + + if (atomic_read(&mqtsdev->buff_in_use)) { + dev_dbg(mqtsdev->dev, "%s buffer not free, schedule next cycle\n", __func__); + goto mod_timer; + } + atomic_set(&mqtsdev->buff_in_use, 1); + + sync_msg = mqtsdev->sync_msg; + sync_msg->header.signature = cpu_to_le16(QAIC_TIMESYNC_SIGNATURE); + sync_msg->header.msg_type = QAIC_TS_SYNC_REQ; + /* Read host UTC time and convert to uS*/ + host_time_us = div_u64(ktime_get_real_ns(), NSEC_PER_USEC); + device_qtimer = read_qtimer(mqtsdev->qtimer_addr); + device_qtimer_us = QAIC_CONV_QTIMER_TO_US(device_qtimer); + /* Offset between host UTC and device time */ + offset_us = host_time_us - device_qtimer_us; + + host_sec = div_u64(offset_us, USEC_PER_SEC); + sync_msg->data.tv_usec = cpu_to_le64(offset_us - host_sec * USEC_PER_SEC); + sync_msg->data.tv_sec = cpu_to_le64(host_sec); + ret = mhi_queue_buf(mqtsdev->mhi_dev, DMA_TO_DEVICE, sync_msg, sizeof(*sync_msg), MHI_EOT); + if (ret && (ret != -EAGAIN)) { + dev_err(mqtsdev->dev, "%s unable to queue to mhi:%d\n", __func__, ret); + return; + } else if (ret == -EAGAIN) { + atomic_set(&mqtsdev->buff_in_use, 0); + } + +mod_timer: + ret = mod_timer(t, jiffies + msecs_to_jiffies(timesync_delay_ms)); + if (ret) + dev_err(mqtsdev->dev, "%s mod_timer error:%d\n", __func__, ret); +} + +static int qaic_timesync_probe(struct mhi_device *mhi_dev, const struct mhi_device_id *id) +{ + struct qaic_device *qdev = pci_get_drvdata(to_pci_dev(mhi_dev->mhi_cntrl->cntrl_dev)); + struct mqts_dev *mqtsdev; + struct timer_list *timer; + int ret; + + mqtsdev = kzalloc(sizeof(*mqtsdev), GFP_KERNEL); + if (!mqtsdev) { + ret = -ENOMEM; + goto out; + } + + timer = &mqtsdev->timer; + mqtsdev->mhi_dev = mhi_dev; + mqtsdev->qdev = qdev; + mqtsdev->dev = &qdev->pdev->dev; + + mqtsdev->sync_msg = kzalloc(sizeof(*mqtsdev->sync_msg), GFP_KERNEL); + if (!mqtsdev->sync_msg) { + ret = -ENOMEM; + goto free_mqts_dev; + } + atomic_set(&mqtsdev->buff_in_use, 0); + + ret = mhi_prepare_for_transfer(mhi_dev); + if (ret) + goto free_sync_msg; + + /* Qtimer register pointer */ + mqtsdev->qtimer_addr = qdev->bar_0 + QTIMER_REG_OFFSET; + timer_setup(timer, qaic_timesync_timer, 0); + timer->expires = jiffies + msecs_to_jiffies(timesync_delay_ms); + add_timer(timer); + dev_set_drvdata(&mhi_dev->dev, mqtsdev); + + return 0; + +free_sync_msg: + kfree(mqtsdev->sync_msg); +free_mqts_dev: + kfree(mqtsdev); +out: + return ret; +}; + +static void qaic_timesync_remove(struct mhi_device *mhi_dev) +{ + struct mqts_dev *mqtsdev = dev_get_drvdata(&mhi_dev->dev); + + del_timer_sync(&mqtsdev->timer); + mhi_unprepare_from_transfer(mqtsdev->mhi_dev); + kfree(mqtsdev->sync_msg); + kfree(mqtsdev); +} + +static const struct mhi_device_id qaic_timesync_match_table[] = { + { .chan = "QAIC_TIMESYNC_PERIODIC"}, + {}, +}; + +MODULE_DEVICE_TABLE(mhi, qaic_timesync_match_table); + +static struct mhi_driver qaic_timesync_driver = { + .id_table = qaic_timesync_match_table, + .remove = qaic_timesync_remove, + .probe = qaic_timesync_probe, + .ul_xfer_cb = qaic_timesync_ul_xfer_cb, + .dl_xfer_cb = qaic_timesync_dl_xfer_cb, + .driver = { + .name = "qaic_timesync_periodic", + }, +}; + +int qaic_timesync_init(void) +{ + return mhi_driver_register(&qaic_timesync_driver); +} + +void qaic_timesync_deinit(void) +{ + mhi_driver_unregister(&qaic_timesync_driver); +} |