cpufreq: exynos4x12: Use the common clock framework to set APLL clock rate

In the exynos4x12_set_apll() function, the APLL frequency is set with
direct register manipulation.

Such approach is not allowed in the common clock framework. The frequency
is changed, but the corresponding clock value is not updated. This causes
wrong frequency read from cpufreq's cpuinfo_cur_freq sysfs attribute.

Also direct manipulation with PLL's S parameter has been removed. It is
already done at PLL35xx code.

Tested at:
- Exynos4412 - Trats2 board (linux 3.12-rc4)

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Reviewed-by: Yadwinder Singh Brar <yadi.brar@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/exynos4x12-cpufreq.c

@@ -128,9 +128,9 @@ static void exynos4x12_set_clkdiv(unsigned int div_index)
 
 static void exynos4x12_set_apll(unsigned int index)
 {
-	unsigned int tmp, pdiv;
+	unsigned int tmp, freq = apll_freq_4x12[index].freq;
 
-	/* 1. MUX_CORE_SEL = MPLL, ARMCLK uses MPLL for lock time */
+	/* MUX_CORE_SEL = MPLL, ARMCLK uses MPLL for lock time */
 	clk_set_parent(moutcore, mout_mpll);
 
 	do {
@@ -140,24 +140,9 @@ static void exynos4x12_set_apll(unsigned int index)
 		tmp &= 0x7;
 	} while (tmp != 0x2);
 
-	/* 2. Set APLL Lock time */
-	pdiv = ((apll_freq_4x12[index].mps >> 8) & 0x3f);
+	clk_set_rate(mout_apll, freq * 1000);
 
-	__raw_writel((pdiv * 250), EXYNOS4_APLL_LOCK);
-
-	/* 3. Change PLL PMS values */
-	tmp = __raw_readl(EXYNOS4_APLL_CON0);
-	tmp &= ~((0x3ff << 16) | (0x3f << 8) | (0x7 << 0));
-	tmp |= apll_freq_4x12[index].mps;
-	__raw_writel(tmp, EXYNOS4_APLL_CON0);
-
-	/* 4. wait_lock_time */
-	do {
-		cpu_relax();
-		tmp = __raw_readl(EXYNOS4_APLL_CON0);
-	} while (!(tmp & (0x1 << EXYNOS4_APLLCON0_LOCKED_SHIFT)));
-
-	/* 5. MUX_CORE_SEL = APLL */
+	/* MUX_CORE_SEL = APLL */
 	clk_set_parent(moutcore, mout_apll);
 
 	do {
@@ -167,52 +152,15 @@ static void exynos4x12_set_apll(unsigned int index)
 	} while (tmp != (0x1 << EXYNOS4_CLKSRC_CPU_MUXCORE_SHIFT));
 }
 
-static bool exynos4x12_pms_change(unsigned int old_index, unsigned int new_index)
-{
-	unsigned int old_pm = apll_freq_4x12[old_index].mps >> 8;
-	unsigned int new_pm = apll_freq_4x12[new_index].mps >> 8;
-
-	return (old_pm == new_pm) ? 0 : 1;
-}
-
 static void exynos4x12_set_frequency(unsigned int old_index,
 				  unsigned int new_index)
 {
-	unsigned int tmp;
-
 	if (old_index > new_index) {
-		if (!exynos4x12_pms_change(old_index, new_index)) {
-			/* 1. Change the system clock divider values */
-			exynos4x12_set_clkdiv(new_index);
-			/* 2. Change just s value in apll m,p,s value */
-			tmp = __raw_readl(EXYNOS4_APLL_CON0);
-			tmp &= ~(0x7 << 0);
-			tmp |= apll_freq_4x12[new_index].mps & 0x7;
-			__raw_writel(tmp, EXYNOS4_APLL_CON0);
-
-		} else {
-			/* Clock Configuration Procedure */
-			/* 1. Change the system clock divider values */
-			exynos4x12_set_clkdiv(new_index);
-			/* 2. Change the apll m,p,s value */
-			exynos4x12_set_apll(new_index);
-		}
+		exynos4x12_set_clkdiv(new_index);
+		exynos4x12_set_apll(new_index);
 	} else if (old_index < new_index) {
-		if (!exynos4x12_pms_change(old_index, new_index)) {
-			/* 1. Change just s value in apll m,p,s value */
-			tmp = __raw_readl(EXYNOS4_APLL_CON0);
-			tmp &= ~(0x7 << 0);
-			tmp |= apll_freq_4x12[new_index].mps & 0x7;
-			__raw_writel(tmp, EXYNOS4_APLL_CON0);
-			/* 2. Change the system clock divider values */
-			exynos4x12_set_clkdiv(new_index);
-		} else {
-			/* Clock Configuration Procedure */
-			/* 1. Change the apll m,p,s value */
-			exynos4x12_set_apll(new_index);
-			/* 2. Change the system clock divider values */
-			exynos4x12_set_clkdiv(new_index);
-		}
+		exynos4x12_set_apll(new_index);
+		exynos4x12_set_clkdiv(new_index);
 	}
 }
 
@@ -250,7 +198,6 @@ int exynos4x12_cpufreq_init(struct exynos_dvfs_info *info)
 	info->volt_table = exynos4x12_volt_table;
 	info->freq_table = exynos4x12_freq_table;
 	info->set_freq = exynos4x12_set_frequency;
-	info->need_apll_change = exynos4x12_pms_change;
 
 	return 0;