Blackfin: add support for cpufreq on SMP systems

Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

arch/blackfin/Kconfig

@@ -1237,7 +1237,6 @@ config PM_BFIN_WAKE_GP
 endmenu
 
 menu "CPU Frequency scaling"
-	depends on !SMP
 
 source "drivers/cpufreq/Kconfig"
 

arch/blackfin/include/asm/time.h

@@ -23,9 +23,7 @@
  */
 
 #ifndef CONFIG_CPU_FREQ
-#define TIME_SCALE 1
-#define __bfin_cycles_off (0)
-#define __bfin_cycles_mod (0)
+# define TIME_SCALE 1
 #else
 /*
  * Blackfin CPU frequency scaling supports max Core Clock 1, 1/2 and 1/4 .
@@ -33,8 +31,11 @@
  * adjust the Core Timer Presale Register. This way we don't lose time.
  */
 #define TIME_SCALE 4
+
+# ifdef CONFIG_CYCLES_CLOCKSOURCE
 extern unsigned long long __bfin_cycles_off;
 extern unsigned int __bfin_cycles_mod;
+# endif
 #endif
 
 #if defined(CONFIG_TICKSOURCE_CORETMR)

arch/blackfin/kernel/time-ts.c

@@ -51,7 +51,11 @@
 
 static notrace cycle_t bfin_read_cycles(struct clocksource *cs)
 {
+#ifdef CONFIG_CPU_FREQ
 	return __bfin_cycles_off + (get_cycles() << __bfin_cycles_mod);
+#else
+	return get_cycles();
+#endif
 }
 
 static struct clocksource bfin_cs_cycles = {

arch/blackfin/mach-common/cpufreq.c

@@ -15,6 +15,8 @@
 #include <asm/time.h>
 #include <asm/dpmc.h>
 
+#define CPUFREQ_CPU 0
+
 /* this is the table of CCLK frequencies, in Hz */
 /* .index is the entry in the auxillary dpm_state_table[] */
 static struct cpufreq_frequency_table bfin_freq_table[] = {
@@ -41,64 +43,114 @@ static struct bfin_dpm_state {
 	unsigned int tscale; /* change the divider on the core timer interrupt */
 } dpm_state_table[3];
 
+#if defined(CONFIG_CYCLES_CLOCKSOURCE)
 /*
-   normalized to maximum frequncy offset for CYCLES,
-   used in time-ts cycles clock source, but could be used
-   somewhere also.
+ * normalized to maximum frequncy offset for CYCLES,
+ * used in time-ts cycles clock source, but could be used
+ * somewhere also.
  */
 unsigned long long __bfin_cycles_off;
 unsigned int __bfin_cycles_mod;
+#endif
 
 /**************************************************************************/
+static void __init bfin_init_tables(unsigned long cclk, unsigned long sclk)
+{
 
-static unsigned int bfin_getfreq_khz(unsigned int cpu)
+	unsigned long csel, min_cclk;
+	int index;
+
+	/* Anomaly 273 seems to still exist on non-BF54x w/dcache turned on */
+#if ANOMALY_05000273 || ANOMALY_05000274 || \
+	(!defined(CONFIG_BF54x) && defined(CONFIG_BFIN_EXTMEM_DCACHEABLE))
+	min_cclk = sclk * 2;
+#else
+	min_cclk = sclk;
+#endif
+	csel = ((bfin_read_PLL_DIV() & CSEL) >> 4);
+
+	for (index = 0;  (cclk >> index) >= min_cclk && csel <= 3; index++, csel++) {
+		bfin_freq_table[index].frequency = cclk >> index;
+		dpm_state_table[index].csel = csel << 4; /* Shift now into PLL_DIV bitpos */
+		dpm_state_table[index].tscale =  (TIME_SCALE / (1 << csel)) - 1;
+
+		pr_debug("cpufreq: freq:%d csel:0x%x tscale:%d\n",
+						 bfin_freq_table[index].frequency,
+						 dpm_state_table[index].csel,
+						 dpm_state_table[index].tscale);
+	}
+	return;
+}
+
+static void bfin_adjust_core_timer(void *info)
 {
-	/* The driver only support single cpu */
-	if (cpu != 0)
-		return -1;
+	unsigned int tscale;
+	unsigned int index = *(unsigned int *)info;
+
+	/* we have to adjust the core timer, because it is using cclk */
+	tscale = dpm_state_table[index].tscale;
+	bfin_write_TSCALE(tscale);
+	return;
+}
 
+static unsigned int bfin_getfreq_khz(unsigned int cpu)
+{
+	/* Both CoreA/B have the same core clock */
 	return get_cclk() / 1000;
 }
 
 
-static int bfin_target(struct cpufreq_policy *policy,
+static int bfin_target(struct cpufreq_policy *poli,
 			unsigned int target_freq, unsigned int relation)
 {
-	unsigned int index, plldiv, tscale;
+	unsigned int index, plldiv, cpu;
 	unsigned long flags, cclk_hz;
 	struct cpufreq_freqs freqs;
+#if defined(CONFIG_CYCLES_CLOCKSOURCE)
 	cycles_t cycles;
+#endif
 
-	if (cpufreq_frequency_table_target(policy, bfin_freq_table,
-		 target_freq, relation, &index))
-		return -EINVAL;
-
-	cclk_hz = bfin_freq_table[index].frequency;
-
-	freqs.old = bfin_getfreq_khz(0);
-	freqs.new = cclk_hz;
-	freqs.cpu = 0;
-
-	pr_debug("cpufreq: changing cclk to %lu; target = %u, oldfreq = %u\n",
-		 cclk_hz, target_freq, freqs.old);
-
-	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
-	local_irq_save_hw(flags);
-		plldiv = (bfin_read_PLL_DIV() & SSEL) | dpm_state_table[index].csel;
-		tscale = dpm_state_table[index].tscale;
-		bfin_write_PLL_DIV(plldiv);
-		/* we have to adjust the core timer, because it is using cclk */
-		bfin_write_TSCALE(tscale);
-		cycles = get_cycles();
-		SSYNC();
-	cycles += 10; /* ~10 cycles we lose after get_cycles() */
-	__bfin_cycles_off += (cycles << __bfin_cycles_mod) - (cycles << index);
-	__bfin_cycles_mod = index;
-	local_irq_restore_hw(flags);
-	/* TODO: just test case for cycles clock source, remove later */
-	pr_debug("cpufreq: done\n");
-	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+	for_each_online_cpu(cpu) {
+		struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
+
+		if (!policy)
+			continue;
+
+		if (cpufreq_frequency_table_target(policy, bfin_freq_table,
+				 target_freq, relation, &index))
+			return -EINVAL;
+
+		cclk_hz = bfin_freq_table[index].frequency;
+
+		freqs.old = bfin_getfreq_khz(0);
+		freqs.new = cclk_hz;
+		freqs.cpu = cpu;
+
+		pr_debug("cpufreq: changing cclk to %lu; target = %u, oldfreq = %u\n",
+			 cclk_hz, target_freq, freqs.old);
+
+		cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+		if (cpu == CPUFREQ_CPU) {
+			local_irq_save_hw(flags);
+			plldiv = (bfin_read_PLL_DIV() & SSEL) |
+						dpm_state_table[index].csel;
+			bfin_write_PLL_DIV(plldiv);
+			on_each_cpu(bfin_adjust_core_timer, &index, 1);
+#if defined(CONFIG_CYCLES_CLOCKSOURCE)
+			cycles = get_cycles();
+			SSYNC();
+			cycles += 10; /* ~10 cycles we lose after get_cycles() */
+			__bfin_cycles_off +=
+			    (cycles << __bfin_cycles_mod) - (cycles << index);
+			__bfin_cycles_mod = index;
+#endif
+			local_irq_restore_hw(flags);
+		}
+		/* TODO: just test case for cycles clock source, remove later */
+		cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+	}
 
+	pr_debug("cpufreq: done\n");
 	return 0;
 }
 
@@ -110,37 +162,16 @@ static int bfin_verify_speed(struct cpufreq_policy *policy)
 static int __init __bfin_cpu_init(struct cpufreq_policy *policy)
 {
 
-	unsigned long cclk, sclk, csel, min_cclk;
-	int index;
-
-	if (policy->cpu != 0)
-		return -EINVAL;
+	unsigned long cclk, sclk;
 
 	cclk = get_cclk() / 1000;
 	sclk = get_sclk() / 1000;
 
-#if ANOMALY_05000273 || ANOMALY_05000274 || \
-	(!defined(CONFIG_BF54x) && defined(CONFIG_BFIN_EXTMEM_DCACHEABLE))
-	min_cclk = sclk * 2;
-#else
-	min_cclk = sclk;
-#endif
-	csel = ((bfin_read_PLL_DIV() & CSEL) >> 4);
-
-	for (index = 0;  (cclk >> index) >= min_cclk && csel <= 3; index++, csel++) {
-		bfin_freq_table[index].frequency = cclk >> index;
-		dpm_state_table[index].csel = csel << 4; /* Shift now into PLL_DIV bitpos */
-		dpm_state_table[index].tscale =  (TIME_SCALE / (1 << csel)) - 1;
-
-		pr_debug("cpufreq: freq:%d csel:0x%x tscale:%d\n",
-						 bfin_freq_table[index].frequency,
-						 dpm_state_table[index].csel,
-						 dpm_state_table[index].tscale);
-	}
+	if (policy->cpu == CPUFREQ_CPU)
+		bfin_init_tables(cclk, sclk);
 
 	policy->cpuinfo.transition_latency = 50000; /* 50us assumed */
 
-	/*Now ,only support one cpu */
 	policy->cur = cclk;
 	cpufreq_frequency_table_get_attr(bfin_freq_table, policy->cpu);
 	return cpufreq_frequency_table_cpuinfo(policy, bfin_freq_table);