[CPUFREQ] powernow-k8: small cleanups / documentation additions (Pavel Machek)

From: Pavel Machek <pavel (AT) ucw.cz>

These are very small cleanups / documentation additions. It avoids
using different names for same fields in different structures.

Updated to latest cpufreq-bk by Dominik Brodowski, and ack'ed by Mark
Langsdorf, Paul Devriendt and Pavel Machek.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Dominik Brodowski <linux@brodo.de>
Signed-off-by: Dave Jones <davej@redhat.com>

arch/i386/kernel/cpu/cpufreq/powernow-k8.c

@@ -18,6 +18,9 @@
  *  Processor information obtained from Chapter 9 (Power and Thermal Management)
  *  of the "BIOS and Kernel Developer's Guide for the AMD Athlon 64 and AMD
  *  Opteron Processors" available for download from www.amd.com
+ *
+ *  Tables for specific CPUs can be infrerred from
+ *	http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/30430.pdf
  */
 
 #include <linux/kernel.h>
@@ -65,7 +68,12 @@ static u32 find_millivolts_from_vid(struct powernow_k8_data *data, u32 vid)
 	return 1550-vid*25;
 }
 
-/* Return the vco fid for an input fid */
+/* Return the vco fid for an input fid
+ *
+ * Each "low" fid has corresponding "high" fid, and you can get to "low" fids
+ * only from corresponding high fids. This returns "high" fid corresponding to
+ * "low" one.
+ */
 static u32 convert_fid_to_vco_fid(u32 fid)
 {
 	if (fid < HI_FID_TABLE_BOTTOM) {
@@ -307,10 +315,7 @@ static int core_voltage_pre_transition(struct powernow_k8_data *data, u32 reqvid
 /* Phase 2 - core frequency transition */
 static int core_frequency_transition(struct powernow_k8_data *data, u32 reqfid)
 {
-	u32 vcoreqfid;
-	u32 vcocurrfid;
-	u32 vcofiddiff;
-	u32 savevid = data->currvid;
+	u32 vcoreqfid, vcocurrfid, vcofiddiff, savevid = data->currvid;
 
 	if ((reqfid < HI_FID_TABLE_BOTTOM) && (data->currfid < HI_FID_TABLE_BOTTOM)) {
 		printk(KERN_ERR PFX "ph2: illegal lo-lo transition 0x%x 0x%x\n",
@@ -498,7 +503,7 @@ static int check_pst_table(struct powernow_k8_data *data, struct pst_s *pst, u8
 		    || (pst[j].fid & 1)
 		    || (j && (pst[j].fid < HI_FID_TABLE_BOTTOM))) {
 			/* Only first fid is allowed to be in "low" range */
-			printk(KERN_ERR PFX "fid %d invalid : 0x%x\n", j, pst[j].fid);
+			printk(KERN_ERR PFX "two low fids - %d : 0x%x\n", j, pst[j].fid);
 			return -EINVAL;
 		}
 		if (pst[j].fid < lastfid)
@@ -618,7 +623,7 @@ static int find_psb_table(struct powernow_k8_data *data)
 			return -ENODEV;
 		}
 
-		data->vstable = psb->voltagestabilizationtime;
+		data->vstable = psb->vstable;
 		dprintk("voltage stabilization time: %d(*20us)\n", data->vstable);
 
 		dprintk("flags2: 0x%x\n", psb->flags2);
@@ -632,8 +637,8 @@ static int find_psb_table(struct powernow_k8_data *data)
 		dprintk("isochronous relief time: %d\n", data->irt);
 		dprintk("maximum voltage step: %d - 0x%x\n", mvs, data->vidmvs);
 
-		dprintk("numpst: 0x%x\n", psb->numpst);
-		cpst = psb->numpst;
+		dprintk("numpst: 0x%x\n", psb->numps);
+		cpst = psb->numps;
 		if ((psb->cpuid == 0x00000fc0) || (psb->cpuid == 0x00000fe0) ){
 			thiscpuid = cpuid_eax(CPUID_PROCESSOR_SIGNATURE);
 			if ((thiscpuid == 0x00000fc0) || (thiscpuid == 0x00000fe0) ) {
@@ -651,7 +656,7 @@ static int find_psb_table(struct powernow_k8_data *data)
 		dprintk("maxvid: 0x%x\n", psb->maxvid);
 		maxvid = psb->maxvid;
 
-		data->numps = psb->numpstates;
+		data->numps = psb->numps;
 		dprintk("numpstates: 0x%x\n", data->numps);
 		return fill_powernow_table(data, (struct pst_s *)(psb+1), maxvid);
 	}

arch/i386/kernel/cpu/cpufreq/powernow-k8.h

@@ -21,8 +21,7 @@ struct powernow_k8_data {
 	u32 plllock; /* pll lock time, units 1 us */
 
 	/* keep track of the current fid / vid */
-	u32 currvid;
-	u32 currfid;
+	u32 currvid, currfid;
 
 	/* the powernow_table includes all frequency and vid/fid pairings:
 	 * fid are the lower 8 bits of the index, vid are the upper 8 bits.
@@ -152,14 +151,14 @@ struct psb_s {
 	u8 signature[10];
 	u8 tableversion;
 	u8 flags1;
-	u16 voltagestabilizationtime;
+	u16 vstable;
 	u8 flags2;
-	u8 numpst;
+	u8 num_tables;
 	u32 cpuid;
 	u8 plllocktime;
 	u8 maxfid;
 	u8 maxvid;
-	u8 numpstates;
+	u8 numps;
 };
 
 /* Pairs of fid/vid values are appended to the version 1.4 PSB table. */