[PATCH 2/2] cpufreq: exynos: Add new Exynos3250 cpufreq driver

From: Chanwoo Choi
Date: Thu Apr 17 2014 - 22:21:33 EST

This patch add new Exynos3250 cpufreq driver to support DVFS (Dynamic Voltage
Frequency Scaling). Exynos3250 uses the Cortex-A7 dual cores and has a target
speed of 1.0 GHz. Exynos3250 cpufreq driver has range from 100MHz to 1000MHz.

Signed-off-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
drivers/cpufreq/Kconfig.arm | 11 +++
drivers/cpufreq/Makefile | 1 +
drivers/cpufreq/exynos-cpufreq.c | 4 +-
drivers/cpufreq/exynos-cpufreq.h | 17 ++++
drivers/cpufreq/exynos3250-cpufreq.c | 158 +++++++++++++++++++++++++++++++++++
5 files changed, 190 insertions(+), 1 deletion(-)
create mode 100644 drivers/cpufreq/exynos3250-cpufreq.c

diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index 0e9cce8..8af1bd1 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -28,6 +28,17 @@ config ARM_VEXPRESS_SPC_CPUFREQ
config ARM_EXYNOS_CPUFREQ
bool

+config ARM_EXYNOS3250_CPUFREQ
+ bool "SAMSUNG EXYNOS3250"
+ depends on SOC_EXYNOS3250 && !ARCH_MULTIPLATFORM
+ default y
+ select ARM_EXYNOS_CPUFREQ
+ help
+ This adds the CPUFreq driver for Samsung EXYNOS3250 SoC based on
+ Cortex-A7 dual-core.
+
+ If in doubt, say N.
+
config ARM_EXYNOS4210_CPUFREQ
bool "SAMSUNG EXYNOS4210"
depends on CPU_EXYNOS4210 && !ARCH_MULTIPLATFORM
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 0dbb963..18260bb 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -50,6 +50,7 @@ obj-$(CONFIG_ARM_DT_BL_CPUFREQ) += arm_big_little_dt.o
obj-$(CONFIG_ARCH_DAVINCI_DA850) += davinci-cpufreq.o
obj-$(CONFIG_UX500_SOC_DB8500) += dbx500-cpufreq.o
obj-$(CONFIG_ARM_EXYNOS_CPUFREQ) += exynos-cpufreq.o
+obj-$(CONFIG_ARM_EXYNOS3250_CPUFREQ) += exynos3250-cpufreq.o
obj-$(CONFIG_ARM_EXYNOS4210_CPUFREQ) += exynos4210-cpufreq.o
obj-$(CONFIG_ARM_EXYNOS4X12_CPUFREQ) += exynos4x12-cpufreq.o
obj-$(CONFIG_ARM_EXYNOS5250_CPUFREQ) += exynos5250-cpufreq.o
diff --git a/drivers/cpufreq/exynos-cpufreq.c b/drivers/cpufreq/exynos-cpufreq.c
index 8b4bb4a..e72cc60 100644
--- a/drivers/cpufreq/exynos-cpufreq.c
+++ b/drivers/cpufreq/exynos-cpufreq.c
@@ -166,7 +166,9 @@ static int exynos_cpufreq_probe(struct platform_device *pdev)

exynos_info->dev = &pdev->dev;

- if (soc_is_exynos4210())
+ if (soc_is_exynos3250())
+ ret = exynos3250_cpufreq_init(exynos_info);
+ else if (soc_is_exynos4210())
ret = exynos4210_cpufreq_init(exynos_info);
else if (soc_is_exynos4212() || soc_is_exynos4412())
ret = exynos4x12_cpufreq_init(exynos_info);
diff --git a/drivers/cpufreq/exynos-cpufreq.h b/drivers/cpufreq/exynos-cpufreq.h
index b72ff10..9c5e491 100644
--- a/drivers/cpufreq/exynos-cpufreq.h
+++ b/drivers/cpufreq/exynos-cpufreq.h
@@ -26,6 +26,15 @@ enum cpufreq_level_index {
.mps = ((m) << 16 | (p) << 8 | (s)), \
}

+#define APLL_FREQ_EXYNOS3(f, a0, a1, a2, a3, a4, a5, b0, b1, b2, m, p, s) \
+ { \
+ .freq = (f) * 1000, \
+ .clk_div_cpu0 = ((a0) | (a1) << 4 | (a2) << 16 | (a3) << 20 | \
+ (a4) << 24 | (a5) << 28), \
+ .clk_div_cpu1 = (b0 << 0 | b1 << 4 | b2 << 8), \
+ .mps = ((m) << 16 | (p) << 8 | (s)), \
+ }
+
struct apll_freq {
unsigned int freq;
u32 clk_div_cpu0;
@@ -44,6 +53,14 @@ struct exynos_dvfs_info {
bool (*need_apll_change)(unsigned int, unsigned int);
};

+#ifdef CONFIG_ARM_EXYNOS3250_CPUFREQ
+extern int exynos3250_cpufreq_init(struct exynos_dvfs_info *);
+#else
+static inline int exynos3250_cpufreq_init(struct exynos_dvfs_info *info)
+{
+ return -EOPNOTSUPP;
+}
+#endif
#ifdef CONFIG_ARM_EXYNOS4210_CPUFREQ
extern int exynos4210_cpufreq_init(struct exynos_dvfs_info *);
#else
diff --git a/drivers/cpufreq/exynos3250-cpufreq.c b/drivers/cpufreq/exynos3250-cpufreq.c
new file mode 100644
index 0000000..71f72b8
--- /dev/null
+++ b/drivers/cpufreq/exynos3250-cpufreq.c
@@ -0,0 +1,158 @@
+/*
+ * Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ * http://www.samsung.com
+ *
+ * EXYNOS3250 - CPU frequency scaling support
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/cpufreq.h>
+
+#include "exynos-cpufreq.h"
+
+static struct clk *cpu_clk;
+static struct clk *mout_core;
+static struct clk *mout_mpll;
+static struct clk *mout_apll;
+
+static unsigned int exynos3250_volt_table[] = {
+ 1050000, 1050000, 1000000, 950000, 900000,
+ 900000, 900000, 900000, 900000, 900000,
+};
+
+static struct cpufreq_frequency_table exynos3250_freq_table[] = {
+ {0, L0, 1000 * 1000},
+ {0, L1, 900 * 1000},
+ {0, L2, 800 * 1000},
+ {0, L3, 700 * 1000},
+ {0, L4, 600 * 1000},
+ {0, L5, 500 * 1000},
+ {0, L6, 400 * 1000},
+ {0, L7, 300 * 1000},
+ {0, L8, 200 * 1000},
+ {0, L9, 100 * 1000},
+ {0, 0, CPUFREQ_TABLE_END},
+};
+
+static struct apll_freq apll_freq_3250[] = {
+ /*
+ * values:
+ * freq
+ * clock divider for CORE, COREM, ATB, PCLK_DBG, APLL, CORE2
+ * clock divider for COPY, HPM, RESERVED
+ * PLL M, P, S
+ */
+ APLL_FREQ_EXYNOS3(1000, 0, 1, 4, 7, 1, 0, 7, 7, 0, 250, 3, 1),
+ APLL_FREQ_EXYNOS3(900, 0, 1, 3, 7, 1, 0, 7, 7, 0, 300, 4, 1),
+ APLL_FREQ_EXYNOS3(800, 0, 1, 3, 7, 1, 0, 7, 7, 0, 200, 3, 1),
+ APLL_FREQ_EXYNOS3(700, 0, 1, 3, 7, 1, 0, 7, 7, 0, 175, 3, 1),
+ APLL_FREQ_EXYNOS3(600, 0, 1, 3, 7, 1, 0, 7, 7, 0, 400, 4, 2),
+ APLL_FREQ_EXYNOS3(500, 0, 1, 3, 7, 1, 0, 7, 7, 0, 250, 3, 2),
+ APLL_FREQ_EXYNOS3(400, 0, 1, 3, 7, 1, 0, 7, 7, 0, 200, 3, 2),
+ APLL_FREQ_EXYNOS3(300, 0, 1, 3, 5, 1, 0, 7, 7, 0, 400, 4, 3),
+ APLL_FREQ_EXYNOS3(200, 0, 1, 3, 3, 1, 0, 7, 7, 0, 200, 3, 3),
+ APLL_FREQ_EXYNOS3(100, 0, 1, 1, 1, 1, 0, 7, 7, 0, 200, 3, 4),
+};
+
+static void exynos3250_set_clkdiv(unsigned int div_index)
+{
+ unsigned int tmp;
+
+ /* Change Divider - CPU0 */
+ tmp = apll_freq_3250[div_index].clk_div_cpu0;
+
+ __raw_writel(tmp, EXYNOS4_CLKDIV_CPU);
+
+ while (__raw_readl(EXYNOS4_CLKDIV_STATCPU) & 0x11111111)
+ cpu_relax();
+
+ /* Change Divider - CPU1 */
+ tmp = apll_freq_3250[div_index].clk_div_cpu1;
+
+ __raw_writel(tmp, EXYNOS4_CLKDIV_CPU1);
+
+ while (__raw_readl(EXYNOS4_CLKDIV_STATCPU1) & 0x111)
+ cpu_relax();
+}
+
+static void exynos3250_set_apll(unsigned int index)
+{
+ unsigned int tmp, freq = apll_freq_3250[index].freq * 1000;
+ struct clk *clk;
+
+ clk = clk_get_parent(mout_apll);
+
+ /* MUX_CORE_SEL = MPLL, ARMCLK uses MPLL for lock time */
+ clk_set_parent(mout_core, mout_mpll);
+ do {
+ cpu_relax();
+ tmp = (__raw_readl(EXYNOS4_CLKMUX_STATCPU)
+ >> EXYNOS4_CLKSRC_CPU_MUXCORE_SHIFT);
+ tmp &= 0x7;
+ } while (tmp != 0x2);
+
+ clk_set_rate(clk, freq);
+
+ /* MUX_CORE_SEL = APLL */
+ clk_set_parent(mout_core, mout_apll);
+ do {
+ cpu_relax();
+ tmp = __raw_readl(EXYNOS4_CLKMUX_STATCPU);
+ tmp &= EXYNOS4_CLKMUX_STATCPU_MUXCORE_MASK;
+ } while (tmp != (0x1 << EXYNOS4_CLKSRC_CPU_MUXCORE_SHIFT));
+}
+
+static void exynos3250_set_frequency(unsigned int old_index,
+ unsigned int new_index)
+{
+ if (old_index > new_index) {
+ exynos3250_set_clkdiv(new_index);
+ exynos3250_set_apll(new_index);
+ } else if (old_index < new_index) {
+ exynos3250_set_apll(new_index);
+ exynos3250_set_clkdiv(new_index);
+ }
+}
+
+int exynos3250_cpufreq_init(struct exynos_dvfs_info *info)
+{
+ unsigned long rate;
+
+ cpu_clk = devm_clk_get(info->dev, "div_core2");
+ if (IS_ERR(cpu_clk))
+ return PTR_ERR(cpu_clk);
+
+ mout_core = devm_clk_get(info->dev, "mout_core");
+ if (IS_ERR(mout_core))
+ return PTR_ERR(mout_core);
+
+ mout_mpll = devm_clk_get(info->dev, "mout_mpll_user_c");
+ if (IS_ERR(mout_mpll))
+ return PTR_ERR(mout_mpll);
+ rate = clk_get_rate(mout_mpll) / 1000;
+
+ mout_apll = devm_clk_get(info->dev, "mout_apll");
+ if (IS_ERR(mout_apll))
+ return PTR_ERR(mout_apll);
+
+ info->mpll_freq_khz = rate;
+ info->pll_safe_idx = L2;
+ info->cpu_clk = cpu_clk;
+
+ info->volt_table = exynos3250_volt_table;
+ info->freq_table = exynos3250_freq_table;
+ info->set_freq = exynos3250_set_frequency;
+
+ return 0;
+}
+EXPORT_SYMBOL(exynos3250_cpufreq_init);
--
1.8.0

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