intel_pmc_core: Convert to DEFINE_DEBUGFS_ATTRIBUTE

Refactor the code to use the recently introduced
DEFINE_DEBUGFS_ATTRIBUTE() macro to eliminate boilerplate code.
Make the absence of DEBUG_FS a non-fatal error.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-and-tested-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@intel.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>

2 files changed, 11 insertions, 37 deletions

diff --git a/drivers/platform/x86/intel_pmc_core.c b/drivers/platform/x86/intel_pmc_core.c
index 2776bec89c88..d8379cd86516 100644
--- a/drivers/platform/x86/intel_pmc_core.c
+++ b/drivers/platform/x86/intel_pmc_core.c
@@ -23,7 +23,6 @@
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/pci.h>
-#include <linux/seq_file.h>
 
 #include <asm/cpu_device_id.h>
 #include <asm/pmc_core.h>
@@ -77,30 +76,18 @@ int intel_pmc_slp_s0_counter_read(u32 *data)
 }
 EXPORT_SYMBOL_GPL(intel_pmc_slp_s0_counter_read);
 
-#if IS_ENABLED(CONFIG_DEBUG_FS)
-static int pmc_core_dev_state_show(struct seq_file *s, void *unused)
+static int pmc_core_dev_state_get(void *data, u64 *val)
 {
-        struct pmc_dev *pmcdev = s->private;
-        u32 counter_val;
+        struct pmc_dev *pmcdev = data;
+        u32 value;
 
-        counter_val = pmc_core_reg_read(pmcdev,
-                                        SPT_PMC_SLP_S0_RES_COUNTER_OFFSET);
-        seq_printf(s, "%u\n", pmc_core_adjust_slp_s0_step(counter_val));
+        value = pmc_core_reg_read(pmcdev, SPT_PMC_SLP_S0_RES_COUNTER_OFFSET);
+        *val = pmc_core_adjust_slp_s0_step(value);
 
         return 0;
 }
 
-static int pmc_core_dev_state_open(struct inode *inode, struct file *file)
-{
-        return single_open(file, pmc_core_dev_state_show, inode->i_private);
-}
-
-static const struct file_operations pmc_core_dev_state_ops = {
-        .open           = pmc_core_dev_state_open,
-        .read           = seq_read,
-        .llseek         = seq_lseek,
-        .release        = single_release,
-};
+DEFINE_DEBUGFS_ATTRIBUTE(pmc_core_dev_state, pmc_core_dev_state_get, NULL, "%llu\n");
 
 static void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev)
 {
@@ -112,12 +99,12 @@ static int pmc_core_dbgfs_register(struct pmc_dev *pmcdev)
         struct dentry *dir, *file;
 
         dir = debugfs_create_dir("pmc_core", NULL);
-        if (!dir)
+        if (IS_ERR_OR_NULL(dir))
                 return -ENOMEM;
 
         pmcdev->dbgfs_dir = dir;
         file = debugfs_create_file("slp_s0_residency_usec", S_IFREG | S_IRUGO,
-                                   dir, pmcdev, &pmc_core_dev_state_ops);
+                                   dir, pmcdev, &pmc_core_dev_state);
 
         if (!file) {
                 pmc_core_dbgfs_unregister(pmcdev);
@@ -126,16 +113,6 @@ static int pmc_core_dbgfs_register(struct pmc_dev *pmcdev)
 
         return 0;
 }
-#else
-static inline int pmc_core_dbgfs_register(struct pmc_dev *pmcdev)
-{
-        return 0;
-}
-
-static inline void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev)
-{
-}
-#endif /* CONFIG_DEBUG_FS */
 
 static const struct x86_cpu_id intel_pmc_core_ids[] = {
         { X86_VENDOR_INTEL, 6, 0x4e, X86_FEATURE_MWAIT,
@@ -182,10 +159,8 @@ static int pmc_core_probe(struct pci_dev *dev, const struct pci_device_id *id)
         }
 
         err = pmc_core_dbgfs_register(pmcdev);
-        if (err < 0) {
-                dev_err(&dev->dev, "PMC Core: debugfs register failed.\n");
-                return err;
-        }
+        if (err < 0)
+                dev_warn(&dev->dev, "PMC Core: debugfs register failed.\n");
 
         pmc.has_slp_s0_res = true;
         return 0;
diff --git a/drivers/platform/x86/intel_pmc_core.h b/drivers/platform/x86/intel_pmc_core.h
index a9dadaf787c1..e3f671f4d122 100644
--- a/drivers/platform/x86/intel_pmc_core.h
+++ b/drivers/platform/x86/intel_pmc_core.h
@@ -23,6 +23,7 @@
 
 /* Sunrise Point Power Management Controller PCI Device ID */
 #define SPT_PMC_PCI_DEVICE_ID                   0x9d21
+
 #define SPT_PMC_BASE_ADDR_OFFSET                0x48
 #define SPT_PMC_SLP_S0_RES_COUNTER_OFFSET       0x13c
 #define SPT_PMC_MMIO_REG_LEN                    0x100
@@ -42,9 +43,7 @@
 struct pmc_dev {
         u32 base_addr;
         void __iomem *regbase;
-#if IS_ENABLED(CONFIG_DEBUG_FS)
         struct dentry *dbgfs_dir;
-#endif /* CONFIG_DEBUG_FS */
         bool has_slp_s0_res;
 };