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From:   Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
To:     daniel.lezcano@linaro.org, rafael@kernel.org, rui.zhang@intel.com
Cc:     linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
        Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Subject: [PATCH v2 2/7] thermal: int340x: processor_thermal: Add interrupt configuration
Date:   Mon, 17 Jul 2023 12:54:00 -0700
Message-Id: <20230717195405.730869-3-srinivas.pandruvada@linux.intel.com>
In-Reply-To: <20230717195405.730869-1-srinivas.pandruvada@linux.intel.com>
References: <20230717195405.730869-1-srinivas.pandruvada@linux.intel.com>
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Some features like workload type prediction and power floor events
require interrupt support to avoid polling. Here interrupts are enabled
and disabled via sending mailbox commands. The mailbox command ID is
0x1E for read and 0x1F for write.

The interrupt configuration will require mutex protection as it involves
read-modify-write operation. Since mutex are already used in the mailbox
read/write functions: send_mbox_write_cmd() and send_mbox_read_cmd(),
there will be double locking. But, this can be avoided by moving mutexes
from mailbox read/write processing functions to the callers:
processor_thermal_send_mbox_[read|write]_cmd().

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
v2
Added additional comment in the commit log for the interrupt bit

 .../processor_thermal_device.h                |  2 +
 .../int340x_thermal/processor_thermal_mbox.c  | 85 ++++++++++++++-----
 2 files changed, 68 insertions(+), 19 deletions(-)

diff --git a/drivers/thermal/intel/int340x_thermal/processor_thermal_device.h b/drivers/thermal/intel/int340x_thermal/processor_thermal_device.h
index 7cdeca2edc21..defc919cb020 100644
--- a/drivers/thermal/intel/int340x_thermal/processor_thermal_device.h
+++ b/drivers/thermal/intel/int340x_thermal/processor_thermal_device.h
@@ -91,6 +91,8 @@ void proc_thermal_wlt_req_remove(struct pci_dev *pdev);
 
 int processor_thermal_send_mbox_read_cmd(struct pci_dev *pdev, u16 id, u64 *resp);
 int processor_thermal_send_mbox_write_cmd(struct pci_dev *pdev, u16 id, u32 data);
+int processor_thermal_mbox_interrupt_config(struct pci_dev *pdev, bool enable, int enable_bit,
+					    int time_window);
 int proc_thermal_add(struct device *dev, struct proc_thermal_device *priv);
 void proc_thermal_remove(struct proc_thermal_device *proc_priv);
 int proc_thermal_suspend(struct device *dev);
diff --git a/drivers/thermal/intel/int340x_thermal/processor_thermal_mbox.c b/drivers/thermal/intel/int340x_thermal/processor_thermal_mbox.c
index ec766c5615b7..7ef0af3f5bef 100644
--- a/drivers/thermal/intel/int340x_thermal/processor_thermal_mbox.c
+++ b/drivers/thermal/intel/int340x_thermal/processor_thermal_mbox.c
@@ -45,23 +45,16 @@ static int send_mbox_write_cmd(struct pci_dev *pdev, u16 id, u32 data)
 	int ret;
 
 	proc_priv = pci_get_drvdata(pdev);
-
-	mutex_lock(&mbox_lock);
-
 	ret = wait_for_mbox_ready(proc_priv);
 	if (ret)
-		goto unlock_mbox;
+		return ret;
 
 	writel(data, (proc_priv->mmio_base + MBOX_OFFSET_DATA));
 	/* Write command register */
 	reg_data = BIT_ULL(MBOX_BUSY_BIT) | id;
 	writel(reg_data, (proc_priv->mmio_base + MBOX_OFFSET_INTERFACE));
 
-	ret = wait_for_mbox_ready(proc_priv);
-
-unlock_mbox:
-	mutex_unlock(&mbox_lock);
-	return ret;
+	return wait_for_mbox_ready(proc_priv);
 }
 
 static int send_mbox_read_cmd(struct pci_dev *pdev, u16 id, u64 *resp)
@@ -71,12 +64,9 @@ static int send_mbox_read_cmd(struct pci_dev *pdev, u16 id, u64 *resp)
 	int ret;
 
 	proc_priv = pci_get_drvdata(pdev);
-
-	mutex_lock(&mbox_lock);
-
 	ret = wait_for_mbox_ready(proc_priv);
 	if (ret)
-		goto unlock_mbox;
+		return ret;
 
 	/* Write command register */
 	reg_data = BIT_ULL(MBOX_BUSY_BIT) | id;
@@ -84,28 +74,85 @@ static int send_mbox_read_cmd(struct pci_dev *pdev, u16 id, u64 *resp)
 
 	ret = wait_for_mbox_ready(proc_priv);
 	if (ret)
-		goto unlock_mbox;
+		return ret;
 
 	if (id == MBOX_CMD_WORKLOAD_TYPE_READ)
 		*resp = readl(proc_priv->mmio_base + MBOX_OFFSET_DATA);
 	else
 		*resp = readq(proc_priv->mmio_base + MBOX_OFFSET_DATA);
 
-unlock_mbox:
-	mutex_unlock(&mbox_lock);
-	return ret;
+	return 0;
 }
 
 int processor_thermal_send_mbox_read_cmd(struct pci_dev *pdev, u16 id, u64 *resp)
 {
-	return send_mbox_read_cmd(pdev, id, resp);
+	int ret;
+
+	mutex_lock(&mbox_lock);
+	ret = send_mbox_read_cmd(pdev, id, resp);
+	mutex_unlock(&mbox_lock);
+
+	return ret;
 }
 EXPORT_SYMBOL_NS_GPL(processor_thermal_send_mbox_read_cmd, INT340X_THERMAL);
 
 int processor_thermal_send_mbox_write_cmd(struct pci_dev *pdev, u16 id, u32 data)
 {
-	return send_mbox_write_cmd(pdev, id, data);
+	int ret;
+
+	mutex_lock(&mbox_lock);
+	ret = send_mbox_write_cmd(pdev, id, data);
+	mutex_unlock(&mbox_lock);
+
+	return ret;
 }
 EXPORT_SYMBOL_NS_GPL(processor_thermal_send_mbox_write_cmd, INT340X_THERMAL);
 
+#define MBOX_CAMARILLO_RD_INTR_CONFIG	0x1E
+#define MBOX_CAMARILLO_WR_INTR_CONFIG	0x1F
+#define WLT_TW_MASK			GENMASK_ULL(30, 24)
+#define SOC_PREDICTION_TW_SHIFT		24
+
+int processor_thermal_mbox_interrupt_config(struct pci_dev *pdev, bool enable,
+					    int enable_bit, int time_window)
+{
+	u64 data;
+	int ret;
+
+	if (!pdev)
+		return -ENODEV;
+
+	mutex_lock(&mbox_lock);
+
+	/* Do read modify write for MBOX_CAMARILLO_RD_INTR_CONFIG */
+
+	ret = send_mbox_read_cmd(pdev, MBOX_CAMARILLO_RD_INTR_CONFIG,  &data);
+	if (ret) {
+		dev_err(&pdev->dev, "MBOX_CAMARILLO_RD_INTR_CONFIG failed\n");
+		goto unlock;
+	}
+
+	if (time_window >= 0) {
+		data &= ~WLT_TW_MASK;
+
+		/* Program notification delay */
+		data |= (time_window << SOC_PREDICTION_TW_SHIFT);
+	}
+
+	if (enable)
+		data |= BIT(enable_bit);
+	else
+		data &= ~BIT(enable_bit);
+
+	ret = send_mbox_write_cmd(pdev, MBOX_CAMARILLO_WR_INTR_CONFIG, data);
+	if (ret)
+		dev_err(&pdev->dev, "MBOX_CAMARILLO_WR_INTR_CONFIG failed\n");
+
+unlock:
+	mutex_unlock(&mbox_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(processor_thermal_mbox_interrupt_config, INT340X_THERMAL);
+
 MODULE_LICENSE("GPL v2");
-- 
2.38.1