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From:   Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
To:     rafael@kernel.org, rui.zhang@intel.com, daniel.lezcano@linaro.org
Cc:     linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
        Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Subject: [PATCH 2/7] thermal: int340x: processor_thermal: Add interrupt configuration
Date:   Tue, 20 Jun 2023 16:01:45 -0700
Message-Id: <20230620230150.3068704-3-srinivas.pandruvada@linux.intel.com>
In-Reply-To: <20230620230150.3068704-1-srinivas.pandruvada@linux.intel.com>
References: <20230620230150.3068704-1-srinivas.pandruvada@linux.intel.com>
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Some features on this PCI devices require interrupt support. Here
interrupts are enabled/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
involved 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 calling (exported) functions.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
 .../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