cpufreq: exynos: Fix driver compilation with ARCH_MULTIPLATFORM

Currently Exynos cpufreq drivers rely on globally mapped
clock controller registers to configure frequency of CPU
cores. This is obviously wrong and will be removed in near
future, but to enable support for multi-platform builds
without introducing a regression it needs to be worked
around.

This patch hacks the code to look for clock controller node
in device tree and map its registers using of_iomap(),
instead of relying on global mapping, so dependencies on
platform headers are removed and the driver can compile
again with multiplatform support.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

1 files changed, 34 insertions, 6 deletions

diff --git a/drivers/cpufreq/exynos4x12-cpufreq.c b/drivers/cpufreq/exynos4x12-cpufreq.c
index 63a3907ce57..351a2074cfe 100644
--- a/drivers/cpufreq/exynos4x12-cpufreq.c
+++ b/drivers/cpufreq/exynos4x12-cpufreq.c
@@ -16,6 +16,8 @@
 #include <linux/io.h>
 #include <linux/slab.h>
 #include <linux/cpufreq.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
 
 #include "exynos-cpufreq.h"
 
@@ -23,6 +25,7 @@ static struct clk *cpu_clk;
 static struct clk *moutcore;
 static struct clk *mout_mpll;
 static struct clk *mout_apll;
+static struct exynos_dvfs_info *cpufreq;
 
 static unsigned int exynos4x12_volt_table[] = {
 	1350000, 1287500, 1250000, 1187500, 1137500, 1087500, 1037500,
@@ -105,19 +108,20 @@ static void exynos4x12_set_clkdiv(unsigned int div_index)
 
 	tmp = apll_freq_4x12[div_index].clk_div_cpu0;
 
-	__raw_writel(tmp, EXYNOS4_CLKDIV_CPU);
+	__raw_writel(tmp, cpufreq->cmu_regs + EXYNOS4_CLKDIV_CPU);
 
-	while (__raw_readl(EXYNOS4_CLKDIV_STATCPU) & 0x11111111)
+	while (__raw_readl(cpufreq->cmu_regs + EXYNOS4_CLKDIV_STATCPU)
+	       & 0x11111111)
 		cpu_relax();
 
 	/* Change Divider - CPU1 */
 	tmp = apll_freq_4x12[div_index].clk_div_cpu1;
 
-	__raw_writel(tmp, EXYNOS4_CLKDIV_CPU1);
+	__raw_writel(tmp, cpufreq->cmu_regs + EXYNOS4_CLKDIV_CPU1);
 
 	do {
 		cpu_relax();
-		tmp = __raw_readl(EXYNOS4_CLKDIV_STATCPU1);
+		tmp = __raw_readl(cpufreq->cmu_regs + EXYNOS4_CLKDIV_STATCPU1);
 	} while (tmp != 0x0);
 }
 
@@ -130,7 +134,7 @@ static void exynos4x12_set_apll(unsigned int index)
 
 	do {
 		cpu_relax();
-		tmp = (__raw_readl(EXYNOS4_CLKMUX_STATCPU)
+		tmp = (__raw_readl(cpufreq->cmu_regs + EXYNOS4_CLKMUX_STATCPU)
 			>> EXYNOS4_CLKSRC_CPU_MUXCORE_SHIFT);
 		tmp &= 0x7;
 	} while (tmp != 0x2);
@@ -142,7 +146,7 @@ static void exynos4x12_set_apll(unsigned int index)
 
 	do {
 		cpu_relax();
-		tmp = __raw_readl(EXYNOS4_CLKMUX_STATCPU);
+		tmp = __raw_readl(cpufreq->cmu_regs + EXYNOS4_CLKMUX_STATCPU);
 		tmp &= EXYNOS4_CLKMUX_STATCPU_MUXCORE_MASK;
 	} while (tmp != (0x1 << EXYNOS4_CLKSRC_CPU_MUXCORE_SHIFT));
 }
@@ -161,8 +165,30 @@ static void exynos4x12_set_frequency(unsigned int old_index,
 
 int exynos4x12_cpufreq_init(struct exynos_dvfs_info *info)
 {
+	struct device_node *np;
 	unsigned long rate;
 
+	/*
+	 * HACK: This is a temporary workaround to get access to clock
+	 * controller registers directly and remove static mappings and
+	 * dependencies on platform headers. It is necessary to enable
+	 * Exynos multi-platform support and will be removed together with
+	 * this whole driver as soon as Exynos gets migrated to use
+	 * cpufreq-cpu0 driver.
+	 */
+	np = of_find_compatible_node(NULL, NULL, "samsung,exynos4412-clock");
+	if (!np) {
+		pr_err("%s: failed to find clock controller DT node\n",
+			__func__);
+		return -ENODEV;
+	}
+
+	info->cmu_regs = of_iomap(np, 0);
+	if (!info->cmu_regs) {
+		pr_err("%s: failed to map CMU registers\n", __func__);
+		return -EFAULT;
+	}
+
 	cpu_clk = clk_get(NULL, "armclk");
 	if (IS_ERR(cpu_clk))
 		return PTR_ERR(cpu_clk);
@@ -194,6 +220,8 @@ int exynos4x12_cpufreq_init(struct exynos_dvfs_info *info)
 	info->freq_table = exynos4x12_freq_table;
 	info->set_freq = exynos4x12_set_frequency;
 
+	cpufreq = info;
+
 	return 0;
 
 err_mout_apll: