1 files changed, 465 insertions, 0 deletions

diff --git a/drivers/misc/mei/platform-vsc.c b/drivers/misc/mei/platform-vsc.c
new file mode 100644
index 0000000000..8db0fcf24e
--- /dev/null
+++ b/drivers/misc/mei/platform-vsc.c
@@ -0,0 +1,465 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2023, Intel Corporation.
+ * Intel Visual Sensing Controller Interface Linux driver
+ */
+
+#include <linux/align.h>
+#include <linux/cache.h>
+#include <linux/cleanup.h>
+#include <linux/iopoll.h>
+#include <linux/list.h>
+#include <linux/mei.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/overflow.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/timekeeping.h>
+#include <linux/types.h>
+
+#include <asm-generic/bug.h>
+#include <asm-generic/unaligned.h>
+
+#include "mei_dev.h"
+#include "vsc-tp.h"
+
+#define MEI_VSC_DRV_NAME		"intel_vsc"
+
+#define MEI_VSC_MAX_MSG_SIZE		512
+
+#define MEI_VSC_POLL_DELAY_US		(50 * USEC_PER_MSEC)
+#define MEI_VSC_POLL_TIMEOUT_US		(200 * USEC_PER_MSEC)
+
+#define mei_dev_to_vsc_hw(dev)		((struct mei_vsc_hw *)((dev)->hw))
+
+struct mei_vsc_host_timestamp {
+	u64 realtime;
+	u64 boottime;
+};
+
+struct mei_vsc_hw {
+	struct vsc_tp *tp;
+
+	bool fw_ready;
+	bool host_ready;
+
+	atomic_t write_lock_cnt;
+
+	u32 rx_len;
+	u32 rx_hdr;
+
+	/* buffer for tx */
+	char tx_buf[MEI_VSC_MAX_MSG_SIZE + sizeof(struct mei_msg_hdr)] ____cacheline_aligned;
+	/* buffer for rx */
+	char rx_buf[MEI_VSC_MAX_MSG_SIZE + sizeof(struct mei_msg_hdr)] ____cacheline_aligned;
+};
+
+static int mei_vsc_read_helper(struct mei_vsc_hw *hw, u8 *buf,
+			       u32 max_len)
+{
+	struct mei_vsc_host_timestamp ts = {
+		.realtime = ktime_to_ns(ktime_get_real()),
+		.boottime = ktime_to_ns(ktime_get_boottime()),
+	};
+
+	return vsc_tp_xfer(hw->tp, VSC_TP_CMD_READ, &ts, sizeof(ts),
+			   buf, max_len);
+}
+
+static int mei_vsc_write_helper(struct mei_vsc_hw *hw, u8 *buf, u32 len)
+{
+	u8 status;
+
+	return vsc_tp_xfer(hw->tp, VSC_TP_CMD_WRITE, buf, len, &status,
+			   sizeof(status));
+}
+
+static int mei_vsc_fw_status(struct mei_device *mei_dev,
+			     struct mei_fw_status *fw_status)
+{
+	if (!fw_status)
+		return -EINVAL;
+
+	fw_status->count = 0;
+
+	return 0;
+}
+
+static inline enum mei_pg_state mei_vsc_pg_state(struct mei_device *mei_dev)
+{
+	return MEI_PG_OFF;
+}
+
+static void mei_vsc_intr_enable(struct mei_device *mei_dev)
+{
+	struct mei_vsc_hw *hw = mei_dev_to_vsc_hw(mei_dev);
+
+	vsc_tp_intr_enable(hw->tp);
+}
+
+static void mei_vsc_intr_disable(struct mei_device *mei_dev)
+{
+	struct mei_vsc_hw *hw = mei_dev_to_vsc_hw(mei_dev);
+
+	vsc_tp_intr_disable(hw->tp);
+}
+
+/* mei framework requires this ops */
+static void mei_vsc_intr_clear(struct mei_device *mei_dev)
+{
+}
+
+/* wait for pending irq handler */
+static void mei_vsc_synchronize_irq(struct mei_device *mei_dev)
+{
+	struct mei_vsc_hw *hw = mei_dev_to_vsc_hw(mei_dev);
+
+	vsc_tp_intr_synchronize(hw->tp);
+}
+
+static int mei_vsc_hw_config(struct mei_device *mei_dev)
+{
+	return 0;
+}
+
+static bool mei_vsc_host_is_ready(struct mei_device *mei_dev)
+{
+	struct mei_vsc_hw *hw = mei_dev_to_vsc_hw(mei_dev);
+
+	return hw->host_ready;
+}
+
+static bool mei_vsc_hw_is_ready(struct mei_device *mei_dev)
+{
+	struct mei_vsc_hw *hw = mei_dev_to_vsc_hw(mei_dev);
+
+	return hw->fw_ready;
+}
+
+static int mei_vsc_hw_start(struct mei_device *mei_dev)
+{
+	struct mei_vsc_hw *hw = mei_dev_to_vsc_hw(mei_dev);
+	int ret, rlen;
+	u8 buf;
+
+	hw->host_ready = true;
+
+	vsc_tp_intr_enable(hw->tp);
+
+	ret = read_poll_timeout(mei_vsc_read_helper, rlen,
+				rlen >= 0, MEI_VSC_POLL_DELAY_US,
+				MEI_VSC_POLL_TIMEOUT_US, true,
+				hw, &buf, sizeof(buf));
+	if (ret) {
+		dev_err(mei_dev->dev, "wait fw ready failed: %d\n", ret);
+		return ret;
+	}
+
+	hw->fw_ready = true;
+
+	return 0;
+}
+
+static bool mei_vsc_hbuf_is_ready(struct mei_device *mei_dev)
+{
+	struct mei_vsc_hw *hw = mei_dev_to_vsc_hw(mei_dev);
+
+	return atomic_read(&hw->write_lock_cnt) == 0;
+}
+
+static int mei_vsc_hbuf_empty_slots(struct mei_device *mei_dev)
+{
+	return MEI_VSC_MAX_MSG_SIZE / MEI_SLOT_SIZE;
+}
+
+static u32 mei_vsc_hbuf_depth(const struct mei_device *mei_dev)
+{
+	return MEI_VSC_MAX_MSG_SIZE / MEI_SLOT_SIZE;
+}
+
+static int mei_vsc_write(struct mei_device *mei_dev,
+			 const void *hdr, size_t hdr_len,
+			 const void *data, size_t data_len)
+{
+	struct mei_vsc_hw *hw = mei_dev_to_vsc_hw(mei_dev);
+	char *buf = hw->tx_buf;
+	int ret;
+
+	if (WARN_ON(!hdr || !IS_ALIGNED(hdr_len, 4)))
+		return -EINVAL;
+
+	if (!data || data_len > MEI_VSC_MAX_MSG_SIZE)
+		return -EINVAL;
+
+	atomic_inc(&hw->write_lock_cnt);
+
+	memcpy(buf, hdr, hdr_len);
+	memcpy(buf + hdr_len, data, data_len);
+
+	ret = mei_vsc_write_helper(hw, buf, hdr_len + data_len);
+
+	atomic_dec_if_positive(&hw->write_lock_cnt);
+
+	return ret < 0 ? ret : 0;
+}
+
+static inline u32 mei_vsc_read(const struct mei_device *mei_dev)
+{
+	struct mei_vsc_hw *hw = mei_dev_to_vsc_hw(mei_dev);
+	int ret;
+
+	ret = mei_vsc_read_helper(hw, hw->rx_buf, sizeof(hw->rx_buf));
+	if (ret < 0 || ret < sizeof(u32))
+		return 0;
+	hw->rx_len = ret;
+
+	hw->rx_hdr = get_unaligned_le32(hw->rx_buf);
+
+	return hw->rx_hdr;
+}
+
+static int mei_vsc_count_full_read_slots(struct mei_device *mei_dev)
+{
+	return MEI_VSC_MAX_MSG_SIZE / MEI_SLOT_SIZE;
+}
+
+static int mei_vsc_read_slots(struct mei_device *mei_dev, unsigned char *buf,
+			      unsigned long len)
+{
+	struct mei_vsc_hw *hw = mei_dev_to_vsc_hw(mei_dev);
+	struct mei_msg_hdr *hdr;
+
+	hdr = (struct mei_msg_hdr *)&hw->rx_hdr;
+	if (len != hdr->length || hdr->length + sizeof(*hdr) != hw->rx_len)
+		return -EINVAL;
+
+	memcpy(buf, hw->rx_buf + sizeof(*hdr), len);
+
+	return 0;
+}
+
+static bool mei_vsc_pg_in_transition(struct mei_device *mei_dev)
+{
+	return mei_dev->pg_event >= MEI_PG_EVENT_WAIT &&
+	       mei_dev->pg_event <= MEI_PG_EVENT_INTR_WAIT;
+}
+
+static bool mei_vsc_pg_is_enabled(struct mei_device *mei_dev)
+{
+	return false;
+}
+
+static int mei_vsc_hw_reset(struct mei_device *mei_dev, bool intr_enable)
+{
+	struct mei_vsc_hw *hw = mei_dev_to_vsc_hw(mei_dev);
+
+	vsc_tp_reset(hw->tp);
+
+	vsc_tp_intr_disable(hw->tp);
+
+	return vsc_tp_init(hw->tp, mei_dev->dev);
+}
+
+static const struct mei_hw_ops mei_vsc_hw_ops = {
+	.fw_status = mei_vsc_fw_status,
+	.pg_state = mei_vsc_pg_state,
+
+	.host_is_ready = mei_vsc_host_is_ready,
+	.hw_is_ready = mei_vsc_hw_is_ready,
+	.hw_reset = mei_vsc_hw_reset,
+	.hw_config = mei_vsc_hw_config,
+	.hw_start = mei_vsc_hw_start,
+
+	.pg_in_transition = mei_vsc_pg_in_transition,
+	.pg_is_enabled = mei_vsc_pg_is_enabled,
+
+	.intr_clear = mei_vsc_intr_clear,
+	.intr_enable = mei_vsc_intr_enable,
+	.intr_disable = mei_vsc_intr_disable,
+	.synchronize_irq = mei_vsc_synchronize_irq,
+
+	.hbuf_free_slots = mei_vsc_hbuf_empty_slots,
+	.hbuf_is_ready = mei_vsc_hbuf_is_ready,
+	.hbuf_depth = mei_vsc_hbuf_depth,
+	.write = mei_vsc_write,
+
+	.rdbuf_full_slots = mei_vsc_count_full_read_slots,
+	.read_hdr = mei_vsc_read,
+	.read = mei_vsc_read_slots,
+};
+
+static void mei_vsc_event_cb(void *context)
+{
+	struct mei_device *mei_dev = context;
+	struct mei_vsc_hw *hw = mei_dev_to_vsc_hw(mei_dev);
+	struct list_head cmpl_list;
+	s32 slots;
+	int ret;
+
+	if (mei_dev->dev_state == MEI_DEV_RESETTING ||
+	    mei_dev->dev_state == MEI_DEV_INITIALIZING)
+		return;
+
+	INIT_LIST_HEAD(&cmpl_list);
+
+	guard(mutex)(&mei_dev->device_lock);
+
+	while (vsc_tp_need_read(hw->tp)) {
+		/* check slots available for reading */
+		slots = mei_count_full_read_slots(mei_dev);
+
+		ret = mei_irq_read_handler(mei_dev, &cmpl_list, &slots);
+		if (ret) {
+			if (ret != -ENODATA) {
+				if (mei_dev->dev_state != MEI_DEV_RESETTING &&
+				    mei_dev->dev_state != MEI_DEV_POWER_DOWN)
+					schedule_work(&mei_dev->reset_work);
+			}
+
+			return;
+		}
+	}
+
+	mei_dev->hbuf_is_ready = mei_hbuf_is_ready(mei_dev);
+	ret = mei_irq_write_handler(mei_dev, &cmpl_list);
+	if (ret)
+		dev_err(mei_dev->dev, "dispatch write request failed: %d\n", ret);
+
+	mei_dev->hbuf_is_ready = mei_hbuf_is_ready(mei_dev);
+	mei_irq_compl_handler(mei_dev, &cmpl_list);
+}
+
+static int mei_vsc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mei_device *mei_dev;
+	struct mei_vsc_hw *hw;
+	struct vsc_tp *tp;
+	int ret;
+
+	tp = *(struct vsc_tp **)dev_get_platdata(dev);
+	if (!tp)
+		return dev_err_probe(dev, -ENODEV, "no platform data\n");
+
+	mei_dev = devm_kzalloc(dev, size_add(sizeof(*mei_dev), sizeof(*hw)),
+			       GFP_KERNEL);
+	if (!mei_dev)
+		return -ENOMEM;
+
+	mei_device_init(mei_dev, dev, false, &mei_vsc_hw_ops);
+	mei_dev->fw_f_fw_ver_supported = 0;
+	mei_dev->kind = "ivsc";
+
+	hw = mei_dev_to_vsc_hw(mei_dev);
+	atomic_set(&hw->write_lock_cnt, 0);
+	hw->tp = tp;
+
+	platform_set_drvdata(pdev, mei_dev);
+
+	vsc_tp_register_event_cb(tp, mei_vsc_event_cb, mei_dev);
+
+	ret = mei_start(mei_dev);
+	if (ret) {
+		dev_err_probe(dev, ret, "init hw failed\n");
+		goto err_cancel;
+	}
+
+	ret = mei_register(mei_dev, dev);
+	if (ret)
+		goto err_stop;
+
+	pm_runtime_enable(mei_dev->dev);
+
+	return 0;
+
+err_stop:
+	mei_stop(mei_dev);
+
+err_cancel:
+	mei_cancel_work(mei_dev);
+
+	mei_disable_interrupts(mei_dev);
+
+	return ret;
+}
+
+static int mei_vsc_remove(struct platform_device *pdev)
+{
+	struct mei_device *mei_dev = platform_get_drvdata(pdev);
+
+	pm_runtime_disable(mei_dev->dev);
+
+	mei_stop(mei_dev);
+
+	mei_disable_interrupts(mei_dev);
+
+	mei_deregister(mei_dev);
+
+	return 0;
+}
+
+static int mei_vsc_suspend(struct device *dev)
+{
+	struct mei_device *mei_dev = dev_get_drvdata(dev);
+	struct mei_vsc_hw *hw = mei_dev_to_vsc_hw(mei_dev);
+
+	mei_stop(mei_dev);
+
+	mei_disable_interrupts(mei_dev);
+
+	vsc_tp_free_irq(hw->tp);
+
+	return 0;
+}
+
+static int mei_vsc_resume(struct device *dev)
+{
+	struct mei_device *mei_dev = dev_get_drvdata(dev);
+	struct mei_vsc_hw *hw = mei_dev_to_vsc_hw(mei_dev);
+	int ret;
+
+	ret = vsc_tp_request_irq(hw->tp);
+	if (ret)
+		return ret;
+
+	ret = mei_restart(mei_dev);
+	if (ret)
+		goto err_free;
+
+	/* start timer if stopped in suspend */
+	schedule_delayed_work(&mei_dev->timer_work, HZ);
+
+	return 0;
+
+err_free:
+	vsc_tp_free_irq(hw->tp);
+
+	return ret;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(mei_vsc_pm_ops, mei_vsc_suspend, mei_vsc_resume);
+
+static const struct platform_device_id mei_vsc_id_table[] = {
+	{ MEI_VSC_DRV_NAME },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, mei_vsc_id_table);
+
+static struct platform_driver mei_vsc_drv = {
+	.probe = mei_vsc_probe,
+	.remove = mei_vsc_remove,
+	.id_table = mei_vsc_id_table,
+	.driver = {
+		.name = MEI_VSC_DRV_NAME,
+		.pm = &mei_vsc_pm_ops,
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+	},
+};
+module_platform_driver(mei_vsc_drv);
+
+MODULE_AUTHOR("Wentong Wu <wentong.wu@intel.com>");
+MODULE_AUTHOR("Zhifeng Wang <zhifeng.wang@intel.com>");
+MODULE_DESCRIPTION("Intel Visual Sensing Controller Interface");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(VSC_TP);