[PATCH V4 10/12] misc: xilinx_sdfec: Add stats & status ioctls

[Dragan Cvetic]

SD-FEC statistic data are:
- count of data interface errors (isr_err_count)
- count of Correctable ECC errors (cecc_count)
- count of Uncorrectable ECC errors (uecc_count)

Add support:
1. clear stats ioctl callback which clears collected
statistic data,
2. get stats ioctl callback which reads a collected
statistic data,
3. set default configuration ioctl callback,
4. start ioctl callback enables SD-FEC HW,
5. stop ioctl callback disables SD-FEC HW.

In a failed state driver enables the following ioctls:
- get status
- get statistics
- clear stats
- set default SD-FEC device configuration

Tested-by: Santhosh Dyavanapally <SDYAVANA@xxxxxxxxxx>
Tested by: Punnaiah Choudary Kalluri <punnaia@xxxxxxxxxx>
Tested-by: Derek Kiernan <derek.kiernan@xxxxxxxxxx>
Tested-by: Dragan Cvetic <dragan.cvetic@xxxxxxxxxx>
Signed-off-by: Derek Kiernan <derek.kiernan@xxxxxxxxxx>
Signed-off-by: Dragan Cvetic <dragan.cvetic@xxxxxxxxxx>
---
 drivers/misc/xilinx_sdfec.c      | 121 +++++++++++++++++++++++++++++++++++++++
 include/uapi/misc/xilinx_sdfec.h |  75 ++++++++++++++++++++++++
 2 files changed, 196 insertions(+)

diff --git a/drivers/misc/xilinx_sdfec.c b/drivers/misc/xilinx_sdfec.c
index 544e746..6e04492 100644
--- a/drivers/misc/xilinx_sdfec.c
+++ b/drivers/misc/xilinx_sdfec.c
@@ -189,6 +189,7 @@ struct xsdfec_clks {
  * @dev: pointer to device struct
  * @state: State of the SDFEC device
  * @config: Configuration of the SDFEC device
+ * @intr_enabled: indicates IRQ enabled
  * @state_updated: indicates State updated by interrupt handler
  * @stats_updated: indicates Stats updated by interrupt handler
  * @isr_err_count: Count of ISR errors
@@ -207,6 +208,7 @@ struct xsdfec_dev {
 	struct device *dev;
 	enum xsdfec_state state;
 	struct xsdfec_config config;
+	bool intr_enabled;
 	bool state_updated;
 	bool stats_updated;
 	atomic_t isr_err_count;
@@ -290,6 +292,26 @@ static int xsdfec_dev_release(struct inode *iptr, struct file *fptr)
 	return 0;
 }
 
+static int xsdfec_get_status(struct xsdfec_dev *xsdfec, void __user *arg)
+{
+	struct xsdfec_status status;
+	int err;
+
+	status.fec_id = xsdfec->config.fec_id;
+	spin_lock_irqsave(&xsdfec->irq_lock, xsdfec->flags);
+	status.state = xsdfec->state;
+	xsdfec->state_updated = false;
+	spin_unlock_irqrestore(&xsdfec->irq_lock, xsdfec->flags);
+	status.activity = (xsdfec_regread(xsdfec, XSDFEC_ACTIVE_ADDR) &
+			   XSDFEC_IS_ACTIVITY_SET);
+
+	err = copy_to_user(arg, &status, sizeof(status));
+	if (err)
+		err = -EFAULT;
+
+	return err;
+}
+
 static int xsdfec_get_config(struct xsdfec_dev *xsdfec, void __user *arg)
 {
 	int err;
@@ -850,6 +872,80 @@ static int xsdfec_cfg_axi_streams(struct xsdfec_dev *xsdfec)
 	return 0;
 }
 
+static int xsdfec_start(struct xsdfec_dev *xsdfec)
+{
+	u32 regread;
+
+	regread = xsdfec_regread(xsdfec, XSDFEC_FEC_CODE_ADDR);
+	regread &= 0x1;
+	if (regread != xsdfec->config.code) {
+		dev_dbg(xsdfec->dev,
+			"%s SDFEC HW code does not match driver code, reg %d, code %d",
+			__func__, regread, xsdfec->config.code);
+		return -EINVAL;
+	}
+
+	/* Set AXIS enable */
+	xsdfec_regwrite(xsdfec, XSDFEC_AXIS_ENABLE_ADDR,
+			XSDFEC_AXIS_ENABLE_MASK);
+	/* Done */
+	xsdfec->state = XSDFEC_STARTED;
+	return 0;
+}
+
+static int xsdfec_stop(struct xsdfec_dev *xsdfec)
+{
+	u32 regread;
+
+	if (xsdfec->state != XSDFEC_STARTED)
+		dev_dbg(xsdfec->dev, "Device not started correctly");
+	/* Disable AXIS_ENABLE Input interfaces only */
+	regread = xsdfec_regread(xsdfec, XSDFEC_AXIS_ENABLE_ADDR);
+	regread &= (~XSDFEC_AXIS_IN_ENABLE_MASK);
+	xsdfec_regwrite(xsdfec, XSDFEC_AXIS_ENABLE_ADDR, regread);
+	/* Stop */
+	xsdfec->state = XSDFEC_STOPPED;
+	return 0;
+}
+
+static int xsdfec_clear_stats(struct xsdfec_dev *xsdfec)
+{
+	atomic_set(&xsdfec->isr_err_count, 0);
+	atomic_set(&xsdfec->uecc_count, 0);
+	atomic_set(&xsdfec->cecc_count, 0);
+
+	return 0;
+}
+
+static int xsdfec_get_stats(struct xsdfec_dev *xsdfec, void __user *arg)
+{
+	int err;
+	struct xsdfec_stats user_stats;
+
+	spin_lock_irqsave(&xsdfec->irq_lock, xsdfec->flags);
+	user_stats.isr_err_count = atomic_read(&xsdfec->isr_err_count);
+	user_stats.cecc_count = atomic_read(&xsdfec->cecc_count);
+	user_stats.uecc_count = atomic_read(&xsdfec->uecc_count);
+	xsdfec->stats_updated = false;
+	spin_unlock_irqrestore(&xsdfec->irq_lock, xsdfec->flags);
+
+	err = copy_to_user(arg, &user_stats, sizeof(user_stats));
+	if (err)
+		err = -EFAULT;
+
+	return err;
+}
+
+static int xsdfec_set_default_config(struct xsdfec_dev *xsdfec)
+{
+	/* Ensure registers are aligned with core configuration */
+	xsdfec_regwrite(xsdfec, XSDFEC_FEC_CODE_ADDR, xsdfec->config.code);
+	xsdfec_cfg_axi_streams(xsdfec);
+	update_config_from_hw(xsdfec);
+
+	return 0;
+}
+
 static long xsdfec_dev_ioctl(struct file *fptr, unsigned int cmd,
 			     unsigned long data)
 {
@@ -861,6 +957,13 @@ static long xsdfec_dev_ioctl(struct file *fptr, unsigned int cmd,
 	if (!xsdfec)
 		return rval;
 
+	/* In failed state allow only reset and get status IOCTLs */
+	if (xsdfec->state == XSDFEC_NEEDS_RESET &&
+	    (cmd != XSDFEC_SET_DEFAULT_CONFIG && cmd != XSDFEC_GET_STATUS &&
+	     cmd != XSDFEC_GET_STATS && cmd != XSDFEC_CLEAR_STATS)) {
+		return -EPERM;
+	}
+
 	if (_IOC_TYPE(cmd) != XSDFEC_MAGIC)
 		return -ENOTTY;
 
@@ -872,9 +975,27 @@ static long xsdfec_dev_ioctl(struct file *fptr, unsigned int cmd,
 	}
 
 	switch (cmd) {
+	case XSDFEC_START_DEV:
+		rval = xsdfec_start(xsdfec);
+		break;
+	case XSDFEC_STOP_DEV:
+		rval = xsdfec_stop(xsdfec);
+		break;
+	case XSDFEC_CLEAR_STATS:
+		rval = xsdfec_clear_stats(xsdfec);
+		break;
+	case XSDFEC_GET_STATS:
+		rval = xsdfec_get_stats(xsdfec, arg);
+		break;
+	case XSDFEC_GET_STATUS:
+		rval = xsdfec_get_status(xsdfec, arg);
+		break;
 	case XSDFEC_GET_CONFIG:
 		rval = xsdfec_get_config(xsdfec, arg);
 		break;
+	case XSDFEC_SET_DEFAULT_CONFIG:
+		rval = xsdfec_set_default_config(xsdfec);
+		break;
 	case XSDFEC_SET_IRQ:
 		rval = xsdfec_set_irq(xsdfec, arg);
 		break;
diff --git a/include/uapi/misc/xilinx_sdfec.h b/include/uapi/misc/xilinx_sdfec.h
index 890930d..08f26c8 100644
--- a/include/uapi/misc/xilinx_sdfec.h
+++ b/include/uapi/misc/xilinx_sdfec.h
@@ -242,6 +242,21 @@ struct xsdfec_config {
 };
 
 /**
+ * struct xsdfec_stats - Stats retrived by ioctl XSDFEC_GET_STATS. Used
+ *			 to buffer atomic_t variables from struct
+ *			 xsdfec_dev. Counts are accumulated until
+ *			 the user clears them.
+ * @isr_err_count: Count of ISR errors
+ * @cecc_count: Count of Correctable ECC errors (SBE)
+ * @uecc_count: Count of Uncorrectable ECC errors (MBE)
+ */
+struct xsdfec_stats {
+	__u32 isr_err_count;
+	__u32 cecc_count;
+	__u32 uecc_count;
+};
+
+/**
  * struct xsdfec_ldpc_param_table_sizes - Used to store sizes of SD-FEC table
  *					  entries for an individual LPDC code
  *					  parameter.
@@ -260,6 +275,32 @@ struct xsdfec_ldpc_param_table_sizes {
  */
 #define XSDFEC_MAGIC 'f'
 /**
+ * DOC: XSDFEC_START_DEV
+ *
+ * @Description
+ *
+ * ioctl to start SD-FEC core
+ *
+ * This fails if the XSDFEC_SET_ORDER ioctl has not been previously called
+ */
+#define XSDFEC_START_DEV _IO(XSDFEC_MAGIC, 0)
+/**
+ * DOC: XSDFEC_STOP_DEV
+ *
+ * @Description
+ *
+ * ioctl to stop the SD-FEC core
+ */
+#define XSDFEC_STOP_DEV _IO(XSDFEC_MAGIC, 1)
+/**
+ * DOC: XSDFEC_GET_STATUS
+ *
+ * @Description
+ *
+ * ioctl that returns status of SD-FEC core
+ */
+#define XSDFEC_GET_STATUS _IOR(XSDFEC_MAGIC, 2, struct xsdfec_status)
+/**
  * DOC: XSDFEC_SET_IRQ
  * @Parameters
  *
@@ -378,4 +419,38 @@ struct xsdfec_ldpc_param_table_sizes {
  * ioctl that determines if SD-FEC is processing data
  */
 #define XSDFEC_IS_ACTIVE _IOR(XSDFEC_MAGIC, 10, bool)
+/**
+ * DOC: XSDFEC_CLEAR_STATS
+ *
+ * @Description
+ *
+ * ioctl that clears error stats collected during interrupts
+ */
+#define XSDFEC_CLEAR_STATS _IO(XSDFEC_MAGIC, 11)
+/**
+ * DOC: XSDFEC_GET_STATS
+ * @Parameters
+ *
+ * @struct xsdfec_stats *
+ *	Pointer to the &struct xsdfec_stats that will contain the updated stats
+ *	values
+ *
+ * @Description
+ *
+ * ioctl that returns SD-FEC core stats
+ *
+ * This can only be used when the driver is in the XSDFEC_STOPPED state
+ */
+#define XSDFEC_GET_STATS _IOR(XSDFEC_MAGIC, 12, struct xsdfec_stats)
+/**
+ * DOC: XSDFEC_SET_DEFAULT_CONFIG
+ *
+ * @Description
+ *
+ * ioctl that returns SD-FEC core to default config, use after a reset
+ *
+ * This can only be used when the driver is in the XSDFEC_STOPPED state
+ */
+#define XSDFEC_SET_DEFAULT_CONFIG _IO(XSDFEC_MAGIC, 13)
+
 #endif /* __XILINX_SDFEC_H__ */
-- 
2.7.4