add new system file

hc

2024-02-20 102a0743326a03cd1a1202ceda21e175b7d3575c

 kernel/drivers/platform/x86/intel_scu_ipc.c
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@@ -19,6 +19,7 @@
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 #include <linux/init.h>
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 #include <linux/interrupt.h>
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 #include <linux/io.h>
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+#include <linux/iopoll.h>
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 #include <linux/module.h>
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 #include <linux/slab.h>
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@@ -232,19 +233,15 @@
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 /* Wait till scu status is busy */
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 static inline int busy_loop(struct intel_scu_ipc_dev *scu)
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 {
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-	unsigned long end = jiffies + IPC_TIMEOUT;
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+	u8 status;
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+	int err;
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-	do {
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-		u32 status;
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+	err = readx_poll_timeout(ipc_read_status, scu, status, !(status & IPC_STATUS_BUSY),
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+				 100, jiffies_to_usecs(IPC_TIMEOUT));
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+	if (err)
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+		return err;
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-		status = ipc_read_status(scu);
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-		if (!(status & IPC_STATUS_BUSY))
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-			return (status & IPC_STATUS_ERR) ? -EIO : 0;
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-
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-		usleep_range(50, 100);
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-	} while (time_before(jiffies, end));
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-
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-	return -ETIMEDOUT;
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+	return (status & IPC_STATUS_ERR) ? -EIO : 0;
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 }
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 /* Wait till ipc ioc interrupt is received or timeout in 10 HZ */
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@@ -252,10 +249,12 @@
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 {
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 	int status;
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-	if (!wait_for_completion_timeout(&scu->cmd_complete, IPC_TIMEOUT))
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-		return -ETIMEDOUT;
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+	wait_for_completion_timeout(&scu->cmd_complete, IPC_TIMEOUT);
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 	status = ipc_read_status(scu);
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+	if (status & IPC_STATUS_BUSY)
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+		return -ETIMEDOUT;
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+
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 	if (status & IPC_STATUS_ERR)
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 		return -EIO;
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@@ -265,6 +264,24 @@
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 static int intel_scu_ipc_check_status(struct intel_scu_ipc_dev *scu)
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 {
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 	return scu->irq > 0 ? ipc_wait_for_interrupt(scu) : busy_loop(scu);
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+}
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+
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+static struct intel_scu_ipc_dev *intel_scu_ipc_get(struct intel_scu_ipc_dev *scu)
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+{
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+	u8 status;
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+
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+	if (!scu)
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+		scu = ipcdev;
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+	if (!scu)
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+		return ERR_PTR(-ENODEV);
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+
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+	status = ipc_read_status(scu);
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+	if (status & IPC_STATUS_BUSY) {
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+		dev_dbg(&scu->dev, "device is busy\n");
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+		return ERR_PTR(-EBUSY);
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+	}
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+
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+	return scu;
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 }
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 /* Read/Write power control(PMIC in Langwell, MSIC in PenWell) registers */
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@@ -280,11 +297,10 @@
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 	memset(cbuf, 0, sizeof(cbuf));
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 	mutex_lock(&ipclock);
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-	if (!scu)
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-		scu = ipcdev;
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-	if (!scu) {
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+	scu = intel_scu_ipc_get(scu);
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+	if (IS_ERR(scu)) {
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 		mutex_unlock(&ipclock);
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-		return -ENODEV;
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+		return PTR_ERR(scu);
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 	}
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 	for (nc = 0; nc < count; nc++, offset += 2) {
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@@ -439,13 +455,12 @@
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 	int err;
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 	mutex_lock(&ipclock);
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-	if (!scu)
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-		scu = ipcdev;
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-	if (!scu) {
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+	scu = intel_scu_ipc_get(scu);
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+	if (IS_ERR(scu)) {
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 		mutex_unlock(&ipclock);
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-		return -ENODEV;
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+		return PTR_ERR(scu);
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 	}
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-	scu = ipcdev;
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+
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 	cmdval = sub << 12 | cmd;
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 	ipc_command(scu, cmdval);
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 	err = intel_scu_ipc_check_status(scu);
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@@ -485,11 +500,10 @@
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 		return -EINVAL;
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 	mutex_lock(&ipclock);
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-	if (!scu)
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-		scu = ipcdev;
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-	if (!scu) {
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+	scu = intel_scu_ipc_get(scu);
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+	if (IS_ERR(scu)) {
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 		mutex_unlock(&ipclock);
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-		return -ENODEV;
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+		return PTR_ERR(scu);
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 	}
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 	memcpy(inbuf, in, inlen);
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@@ -583,7 +597,6 @@
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 	scu->dev.parent = parent;
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 	scu->dev.class = &intel_scu_ipc_class;
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 	scu->dev.release = intel_scu_ipc_release;
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-	dev_set_name(&scu->dev, "intel_scu_ipc");
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 	if (!request_mem_region(scu_data->mem.start, resource_size(&scu_data->mem),
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 				"intel_scu_ipc")) {
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@@ -612,6 +625,7 @@
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 	 * After this point intel_scu_ipc_release() takes care of
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 	 * releasing the SCU IPC resources once refcount drops to zero.
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 	 */
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+	dev_set_name(&scu->dev, "intel_scu_ipc");
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 	err = device_register(&scu->dev);
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 	if (err) {
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 		put_device(&scu->dev);