[PATCH V6 0/4] cpufreq: exynos5440: support for cpufreq driver

[PATCH V6 0/4] cpufreq: exynos5440: support for cpufreq driver

[Amit Daniel Kachhap]

Submitting the V6 version of exynos5440 cpufreq driver. This patchset addresses
all the coding and design concerns raised especially by Viresh.

Changes in V6:
* Used cpufreq post-change notifier call back in case of failure as pointed by
  Viresh.
* Called cpufreq_frequency_table_cpuinfo before calling
  cpufreq_frequency_table_get_attr as pointed by Viresh.
* Used modified API cpufreq_notify_transition.

Changes in V5:
* Removed the unnecessary DT look up entry from mach-exynos5-dt.c.
* Fixed all coding and comments issue raised by Viresh.

Changes in V4:
* Added dev_err logs instead of pr_err.
* Used the devm_ioremap_resource API.
* Implemented several coding guidelines and minor error comments from Sylwester,
  Russell and Viresh.

Changes in V3:
* Converted the driver to probe based as suggested by Viresh. This is also
  beneficial for multiplatform kernel.
* Other coding guidelines related changes.
* Moved the DT node outside cpu0 node as the driver is now a platform
  driver.

Changes in V2:
* Added OPP library support to parse DT parameters.
* Removed a hack to handle interrupts in bootup.
* Implemented other review comments from Viresh and Inder.

All these patches are dependent on Thomas Abraham common clock patches.
(http://www.mail-archive.com/linux-samsung-soc at vger.kernel.org/msg15860.html)
This whole patch series is based on Rafael tree.
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git bleeding-edge

Amit Daniel Kachhap (4):
  cpufreq: exynos: Add cpufreq driver for exynos5440
  cpufreq: exynos: Remove error return even if no soc is found
  arm: exynos: Enable OPP library support for exynos5440
  arm: dts: Add cpufreq controller node for Exynos5440 SoC

 .../bindings/cpufreq/cpufreq-exynos5440.txt        |   28 ++
 arch/arm/boot/dts/exynos5440.dtsi                  |   12 +
 arch/arm/mach-exynos/Kconfig                       |    2 +
 drivers/cpufreq/Kconfig.arm                        |    9 +
 drivers/cpufreq/Makefile                           |    1 +
 drivers/cpufreq/exynos-cpufreq.c                   |    2 +-
 drivers/cpufreq/exynos5440-cpufreq.c               |  479 ++++++++++++++++++++
 7 files changed, 532 insertions(+), 1 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt
 create mode 100644 drivers/cpufreq/exynos5440-cpufreq.c

[PATCH V6 1/4] cpufreq: exynos: Add cpufreq driver for exynos5440

[Amit Daniel Kachhap]

This patch adds dvfs support for exynos5440 SOC. This soc has 4 cores and
they scale at same frequency. The nature of exynos5440 clock controller is
different from previous exynos controllers so not using the common exynos
cpufreq framework. The major difference being interrupt notification for
frequency change. Also, OPP library is used for device tree parsing to get
different parameters like frequency, voltage etc. Since the opp library sorts
the frequency table in ascending order so they are again re-arranged in
descending order. This will have one-to-one mapping with the clock controller
state management logic.

Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
---
 .../bindings/cpufreq/cpufreq-exynos5440.txt        |   28 ++
 drivers/cpufreq/Kconfig.arm                        |    9 +
 drivers/cpufreq/Makefile                           |    1 +
 drivers/cpufreq/exynos5440-cpufreq.c               |  479 ++++++++++++++++++++
 4 files changed, 517 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt
 create mode 100644 drivers/cpufreq/exynos5440-cpufreq.c

diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt
new file mode 100644
index 0000000..caff1a5
--- /dev/null
+++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt
@@ -0,0 +1,28 @@
+
+Exynos5440 cpufreq driver
+-------------------
+
+Exynos5440 SoC cpufreq driver for CPU frequency scaling.
+
+Required properties:
+- interrupts: Interrupt to know the completion of cpu frequency change.
+- operating-points: Table of frequencies and voltage CPU could be transitioned into,
+	in the decreasing order. Frequency should be in KHz units and voltage
+	should be in microvolts.
+
+Optional properties:
+- clock-latency: Clock monitor latency in microsecond.
+
+All the required listed above must be defined under node cpufreq.
+
+Example:
+--------
+	cpufreq at 160000 {
+		compatible = "samsung,exynos5440-cpufreq";
+		reg = <0x160000 0x1000>;
+		interrupts = <0 57 0>;
+		operating-points = <
+				1000000 975000
+				800000  925000>;
+		clock-latency = <100000>;
+	};
diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index f3f3b14..bce2195 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -42,6 +42,15 @@ config ARM_EXYNOS5250_CPUFREQ
 	  This adds the CPUFreq driver for Samsung EXYNOS5250
 	  SoC.
 
+config ARM_EXYNOS5440_CPUFREQ
+	def_bool SOC_EXYNOS5440
+	depends on HAVE_CLK && PM_OPP && OF
+	help
+	  This adds the CPUFreq driver for Samsung EXYNOS5440
+	  SoC. The nature of exynos5440 clock controller is
+	  different than previous exynos controllers so not using
+	  the common exynos framework.
+
 config ARM_HIGHBANK_CPUFREQ
 	tristate "Calxeda Highbank-based"
 	depends on ARCH_HIGHBANK
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 5db1f1f..6ad0b91 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -56,6 +56,7 @@ obj-$(CONFIG_ARM_EXYNOS_CPUFREQ)	+= exynos-cpufreq.o
 obj-$(CONFIG_ARM_EXYNOS4210_CPUFREQ)	+= exynos4210-cpufreq.o
 obj-$(CONFIG_ARM_EXYNOS4X12_CPUFREQ)	+= exynos4x12-cpufreq.o
 obj-$(CONFIG_ARM_EXYNOS5250_CPUFREQ)	+= exynos5250-cpufreq.o
+obj-$(CONFIG_ARM_EXYNOS5440_CPUFREQ)	+= exynos5440-cpufreq.o
 obj-$(CONFIG_ARM_HIGHBANK_CPUFREQ)	+= highbank-cpufreq.o
 obj-$(CONFIG_ARM_IMX6Q_CPUFREQ)		+= imx6q-cpufreq.o
 obj-$(CONFIG_ARM_INTEGRATOR)		+= integrator-cpufreq.o
diff --git a/drivers/cpufreq/exynos5440-cpufreq.c b/drivers/cpufreq/exynos5440-cpufreq.c
new file mode 100644
index 0000000..9c37825
--- /dev/null
+++ b/drivers/cpufreq/exynos5440-cpufreq.c
@@ -0,0 +1,479 @@
+/*
+ * Copyright (c) 2013 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * Amit Daniel Kachhap <amit.daniel@samsung.com>
+ *
+ * EXYNOS5440 - 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/clk.h>
+#include <linux/cpu.h>
+#include <linux/cpufreq.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/opp.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+/* Register definitions */
+#define XMU_DVFS_CTRL		0x0060
+#define XMU_PMU_P0_7		0x0064
+#define XMU_C0_3_PSTATE		0x0090
+#define XMU_P_LIMIT		0x00a0
+#define XMU_P_STATUS		0x00a4
+#define XMU_PMUEVTEN		0x00d0
+#define XMU_PMUIRQEN		0x00d4
+#define XMU_PMUIRQ		0x00d8
+
+/* PMU mask and shift definations */
+#define P_VALUE_MASK		0x7
+
+#define XMU_DVFS_CTRL_EN_SHIFT	0
+
+#define P0_7_CPUCLKDEV_SHIFT	21
+#define P0_7_CPUCLKDEV_MASK	0x7
+#define P0_7_ATBCLKDEV_SHIFT	18
+#define P0_7_ATBCLKDEV_MASK	0x7
+#define P0_7_CSCLKDEV_SHIFT	15
+#define P0_7_CSCLKDEV_MASK	0x7
+#define P0_7_CPUEMA_SHIFT	28
+#define P0_7_CPUEMA_MASK	0xf
+#define P0_7_L2EMA_SHIFT	24
+#define P0_7_L2EMA_MASK		0xf
+#define P0_7_VDD_SHIFT		8
+#define P0_7_VDD_MASK		0x7f
+#define P0_7_FREQ_SHIFT		0
+#define P0_7_FREQ_MASK		0xff
+
+#define C0_3_PSTATE_VALID_SHIFT	8
+#define C0_3_PSTATE_CURR_SHIFT	4
+#define C0_3_PSTATE_NEW_SHIFT	0
+
+#define PSTATE_CHANGED_EVTEN_SHIFT	0
+
+#define PSTATE_CHANGED_IRQEN_SHIFT	0
+
+#define PSTATE_CHANGED_SHIFT		0
+
+/* some constant values for clock divider calculation */
+#define CPU_DIV_FREQ_MAX	500
+#define CPU_DBG_FREQ_MAX	375
+#define CPU_ATB_FREQ_MAX	500
+
+#define PMIC_LOW_VOLT		0x30
+#define PMIC_HIGH_VOLT		0x28
+
+#define CPUEMA_HIGH		0x2
+#define CPUEMA_MID		0x4
+#define CPUEMA_LOW		0x7
+
+#define L2EMA_HIGH		0x1
+#define L2EMA_MID		0x3
+#define L2EMA_LOW		0x4
+
+#define DIV_TAB_MAX	2
+/* frequency unit is 20MHZ */
+#define FREQ_UNIT	20
+#define MAX_VOLTAGE	1550000 /* In microvolt */
+#define VOLTAGE_STEP	12500	/* In microvolt */
+
+#define CPUFREQ_NAME		"exynos5440_dvfs"
+#define DEF_TRANS_LATENCY	100000
+
+enum cpufreq_level_index {
+	L0, L1, L2, L3, L4,
+	L5, L6, L7, L8, L9,
+};
+#define CPUFREQ_LEVEL_END	(L7 + 1)
+
+struct exynos_dvfs_data {
+	void __iomem *base;
+	struct resource *mem;
+	int irq;
+	struct clk *cpu_clk;
+	unsigned int cur_frequency;
+	unsigned int latency;
+	struct cpufreq_frequency_table *freq_table;
+	unsigned int freq_count;
+	struct device *dev;
+	bool dvfs_enabled;
+	struct work_struct irq_work;
+};
+
+static struct exynos_dvfs_data *dvfs_info;
+static DEFINE_MUTEX(cpufreq_lock);
+static struct cpufreq_freqs freqs;
+
+static int init_div_table(void)
+{
+	struct cpufreq_frequency_table *freq_tbl = dvfs_info->freq_table;
+	unsigned int tmp, clk_div, ema_div, freq, volt_id;
+	int i = 0;
+	struct opp *opp;
+
+	for (i = 0; freq_tbl[i].frequency != CPUFREQ_TABLE_END; i++) {
+
+		opp = opp_find_freq_exact(dvfs_info->dev,
+					freq_tbl[i].frequency * 1000, true);
+		if (IS_ERR(opp)) {
+			dev_err(dvfs_info->dev,
+				"failed to find valid OPP for %u KHZ\n",
+				freq_tbl[i].frequency);
+			return PTR_ERR(opp);
+		}
+
+		freq = freq_tbl[i].frequency / 1000; /* In MHZ */
+		clk_div = ((freq / CPU_DIV_FREQ_MAX) & P0_7_CPUCLKDEV_MASK)
+					<< P0_7_CPUCLKDEV_SHIFT;
+		clk_div |= ((freq / CPU_ATB_FREQ_MAX) & P0_7_ATBCLKDEV_MASK)
+					<< P0_7_ATBCLKDEV_SHIFT;
+		clk_div |= ((freq / CPU_DBG_FREQ_MAX) & P0_7_CSCLKDEV_MASK)
+					<< P0_7_CSCLKDEV_SHIFT;
+
+		/* Calculate EMA */
+		volt_id = opp_get_voltage(opp);
+		volt_id = (MAX_VOLTAGE - volt_id) / VOLTAGE_STEP;
+		if (volt_id < PMIC_HIGH_VOLT) {
+			ema_div = (CPUEMA_HIGH << P0_7_CPUEMA_SHIFT) |
+				(L2EMA_HIGH << P0_7_L2EMA_SHIFT);
+		} else if (volt_id > PMIC_LOW_VOLT) {
+			ema_div = (CPUEMA_LOW << P0_7_CPUEMA_SHIFT) |
+				(L2EMA_LOW << P0_7_L2EMA_SHIFT);
+		} else {
+			ema_div = (CPUEMA_MID << P0_7_CPUEMA_SHIFT) |
+				(L2EMA_MID << P0_7_L2EMA_SHIFT);
+		}
+
+		tmp = (clk_div | ema_div | (volt_id << P0_7_VDD_SHIFT)
+			| ((freq / FREQ_UNIT) << P0_7_FREQ_SHIFT));
+
+		__raw_writel(tmp, dvfs_info->base + XMU_PMU_P0_7 + 4 * i);
+	}
+
+	return 0;
+}
+
+static void exynos_enable_dvfs(void)
+{
+	unsigned int tmp, i, cpu;
+	struct cpufreq_frequency_table *freq_table = dvfs_info->freq_table;
+	/* Disable DVFS */
+	__raw_writel(0,	dvfs_info->base + XMU_DVFS_CTRL);
+
+	/* Enable PSTATE Change Event */
+	tmp = __raw_readl(dvfs_info->base + XMU_PMUEVTEN);
+	tmp |= (1 << PSTATE_CHANGED_EVTEN_SHIFT);
+	 __raw_writel(tmp, dvfs_info->base + XMU_PMUEVTEN);
+
+	/* Enable PSTATE Change IRQ */
+	tmp = __raw_readl(dvfs_info->base + XMU_PMUIRQEN);
+	tmp |= (1 << PSTATE_CHANGED_IRQEN_SHIFT);
+	 __raw_writel(tmp, dvfs_info->base + XMU_PMUIRQEN);
+
+	/* Set initial performance index */
+	for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++)
+		if (freq_table[i].frequency == dvfs_info->cur_frequency)
+			break;
+
+	if (freq_table[i].frequency == CPUFREQ_TABLE_END) {
+		dev_crit(dvfs_info->dev, "Boot up frequency not supported\n");
+		/* Assign the highest frequency */
+		i = 0;
+		dvfs_info->cur_frequency = freq_table[i].frequency;
+	}
+
+	dev_info(dvfs_info->dev, "Setting dvfs initial frequency = %uKHZ",
+						dvfs_info->cur_frequency);
+
+	for (cpu = 0; cpu < CONFIG_NR_CPUS; cpu++) {
+		tmp = __raw_readl(dvfs_info->base + XMU_C0_3_PSTATE + cpu * 4);
+		tmp &= ~(P_VALUE_MASK << C0_3_PSTATE_NEW_SHIFT);
+		tmp |= (i << C0_3_PSTATE_NEW_SHIFT);
+		__raw_writel(tmp, dvfs_info->base + XMU_C0_3_PSTATE + cpu * 4);
+	}
+
+	/* Enable DVFS */
+	__raw_writel(1 << XMU_DVFS_CTRL_EN_SHIFT,
+				dvfs_info->base + XMU_DVFS_CTRL);
+}
+
+static int exynos_verify_speed(struct cpufreq_policy *policy)
+{
+	return cpufreq_frequency_table_verify(policy,
+					      dvfs_info->freq_table);
+}
+
+static unsigned int exynos_getspeed(unsigned int cpu)
+{
+	return dvfs_info->cur_frequency;
+}
+
+static int exynos_target(struct cpufreq_policy *policy,
+			  unsigned int target_freq,
+			  unsigned int relation)
+{
+	unsigned int index, tmp;
+	int ret = 0, i;
+	struct cpufreq_frequency_table *freq_table = dvfs_info->freq_table;
+
+	mutex_lock(&cpufreq_lock);
+	freqs.old = dvfs_info->cur_frequency;
+
+	ret = cpufreq_frequency_table_target(policy, freq_table,
+					   target_freq, relation, &index);
+	if (ret)
+		goto out;
+
+	freqs.new = freq_table[index].frequency;
+	freqs.cpu = policy->cpu;
+
+	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
+
+	/* Set the target frequency in all C0_3_PSTATE register */
+	for_each_cpu(i, policy->cpus) {
+		tmp = __raw_readl(dvfs_info->base + XMU_C0_3_PSTATE + i * 4);
+		tmp &= ~(P_VALUE_MASK << C0_3_PSTATE_NEW_SHIFT);
+		tmp |= (index << C0_3_PSTATE_NEW_SHIFT);
+
+		__raw_writel(tmp, dvfs_info->base + XMU_C0_3_PSTATE + i * 4);
+	}
+out:
+	mutex_unlock(&cpufreq_lock);
+	return ret;
+}
+
+static void exynos_cpufreq_work(struct work_struct *work)
+{
+	unsigned int cur_pstate, index;
+	struct cpufreq_policy *policy = cpufreq_cpu_get(0); /* boot CPU */
+	struct cpufreq_frequency_table *freq_table = dvfs_info->freq_table;
+
+	/* Ensure we can access cpufreq structures */
+	if (unlikely(dvfs_info->dvfs_enabled == false))
+		goto skip_work;
+
+	mutex_lock(&cpufreq_lock);
+	freqs.old = dvfs_info->cur_frequency;
+
+	cur_pstate = __raw_readl(dvfs_info->base + XMU_P_STATUS);
+	if (cur_pstate >> C0_3_PSTATE_VALID_SHIFT & 0x1)
+		index = (cur_pstate >> C0_3_PSTATE_CURR_SHIFT) & P_VALUE_MASK;
+	else
+		index = (cur_pstate >> C0_3_PSTATE_NEW_SHIFT) & P_VALUE_MASK;
+
+	if (likely(index < dvfs_info->freq_count)) {
+		freqs.new = freq_table[index].frequency;
+		dvfs_info->cur_frequency = freqs.new;
+	} else {
+		dev_crit(dvfs_info->dev, "New frequency out of range\n");
+		freqs.new = dvfs_info->cur_frequency;
+	}
+	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
+
+	cpufreq_cpu_put(policy);
+	mutex_unlock(&cpufreq_lock);
+skip_work:
+	enable_irq(dvfs_info->irq);
+}
+
+static irqreturn_t exynos_cpufreq_irq(int irq, void *id)
+{
+	unsigned int tmp;
+
+	tmp = __raw_readl(dvfs_info->base + XMU_PMUIRQ);
+	if (tmp >> PSTATE_CHANGED_SHIFT & 0x1) {
+		__raw_writel(tmp, dvfs_info->base + XMU_PMUIRQ);
+		disable_irq_nosync(irq);
+		schedule_work(&dvfs_info->irq_work);
+	}
+	return IRQ_HANDLED;
+}
+
+static void exynos_sort_descend_freq_table(void)
+{
+	struct cpufreq_frequency_table *freq_tbl = dvfs_info->freq_table;
+	int i = 0, index;
+	unsigned int tmp_freq;
+	/*
+	 * Exynos5440 clock controller state logic expects the cpufreq table to
+	 * be in descending order. But the OPP library constructs the table in
+	 * ascending order. So to make the table descending we just need to
+	 * swap the i element with the N - i element.
+	 */
+	for (i = 0; i < dvfs_info->freq_count / 2; i++) {
+		index = dvfs_info->freq_count - i - 1;
+		tmp_freq = freq_tbl[i].frequency;
+		freq_tbl[i].frequency = freq_tbl[index].frequency;
+		freq_tbl[index].frequency = tmp_freq;
+	}
+}
+
+static int exynos_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+	int ret;
+
+	ret = cpufreq_frequency_table_cpuinfo(policy, dvfs_info->freq_table);
+	if (ret) {
+		dev_err(dvfs_info->dev, "Invalid frequency table: %d\n", ret);
+		return ret;
+	}
+
+	policy->cur = dvfs_info->cur_frequency;
+	policy->cpuinfo.transition_latency = dvfs_info->latency;
+	cpumask_setall(policy->cpus);
+
+	cpufreq_frequency_table_get_attr(dvfs_info->freq_table, policy->cpu);
+
+	return 0;
+}
+
+static struct cpufreq_driver exynos_driver = {
+	.flags		= CPUFREQ_STICKY,
+	.verify		= exynos_verify_speed,
+	.target		= exynos_target,
+	.get		= exynos_getspeed,
+	.init		= exynos_cpufreq_cpu_init,
+	.name		= CPUFREQ_NAME,
+};
+
+static const struct of_device_id exynos_cpufreq_match[] = {
+	{
+		.compatible = "samsung,exynos5440-cpufreq",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, exynos_cpufreq_match);
+
+static int exynos_cpufreq_probe(struct platform_device *pdev)
+{
+	int ret = -EINVAL;
+	struct device_node *np;
+	struct resource res;
+
+	np =  pdev->dev.of_node;
+	if (!np)
+		return -ENODEV;
+
+	dvfs_info = devm_kzalloc(&pdev->dev, sizeof(*dvfs_info), GFP_KERNEL);
+	if (!dvfs_info) {
+		ret = -ENOMEM;
+		goto err_put_node;
+	}
+
+	dvfs_info->dev = &pdev->dev;
+
+	ret = of_address_to_resource(np, 0, &res);
+	if (ret)
+		goto err_put_node;
+
+	dvfs_info->base = devm_ioremap_resource(dvfs_info->dev, &res);
+	if (IS_ERR(dvfs_info->base)) {
+		ret = PTR_ERR(dvfs_info->base);
+		goto err_put_node;
+	}
+
+	dvfs_info->irq = irq_of_parse_and_map(np, 0);
+	if (!dvfs_info->irq) {
+		dev_err(dvfs_info->dev, "No cpufreq irq found\n");
+		ret = -ENODEV;
+		goto err_put_node;
+	}
+
+	ret = of_init_opp_table(dvfs_info->dev);
+	if (ret) {
+		dev_err(dvfs_info->dev, "failed to init OPP table: %d\n", ret);
+		goto err_put_node;
+	}
+
+	ret = opp_init_cpufreq_table(dvfs_info->dev, &dvfs_info->freq_table);
+	if (ret) {
+		dev_err(dvfs_info->dev,
+			"failed to init cpufreq table: %d\n", ret);
+		goto err_put_node;
+	}
+	dvfs_info->freq_count = opp_get_opp_count(dvfs_info->dev);
+	exynos_sort_descend_freq_table();
+
+	if (of_property_read_u32(np, "clock-latency", &dvfs_info->latency))
+		dvfs_info->latency = DEF_TRANS_LATENCY;
+
+	dvfs_info->cpu_clk = devm_clk_get(dvfs_info->dev, "armclk");
+	if (IS_ERR(dvfs_info->cpu_clk)) {
+		dev_err(dvfs_info->dev, "Failed to get cpu clock\n");
+		ret = PTR_ERR(dvfs_info->cpu_clk);
+		goto err_free_table;
+	}
+
+	dvfs_info->cur_frequency = clk_get_rate(dvfs_info->cpu_clk);
+	if (!dvfs_info->cur_frequency) {
+		dev_err(dvfs_info->dev, "Failed to get clock rate\n");
+		ret = -EINVAL;
+		goto err_free_table;
+	}
+	dvfs_info->cur_frequency /= 1000;
+
+	INIT_WORK(&dvfs_info->irq_work, exynos_cpufreq_work);
+	ret = devm_request_irq(dvfs_info->dev, dvfs_info->irq,
+				exynos_cpufreq_irq, IRQF_TRIGGER_NONE,
+				CPUFREQ_NAME, dvfs_info);
+	if (ret) {
+		dev_err(dvfs_info->dev, "Failed to register IRQ\n");
+		goto err_free_table;
+	}
+
+	ret = init_div_table();
+	if (ret) {
+		dev_err(dvfs_info->dev, "Failed to initialise div table\n");
+		goto err_free_table;
+	}
+
+	exynos_enable_dvfs();
+	ret = cpufreq_register_driver(&exynos_driver);
+	if (ret) {
+		dev_err(dvfs_info->dev,
+			"%s: failed to register cpufreq driver\n", __func__);
+		goto err_free_table;
+	}
+
+	of_node_put(np);
+	dvfs_info->dvfs_enabled = true;
+	return 0;
+
+err_free_table:
+	opp_free_cpufreq_table(dvfs_info->dev, &dvfs_info->freq_table);
+err_put_node:
+	of_node_put(np);
+	dev_err(dvfs_info->dev, "%s: failed initialization\n", __func__);
+	return ret;
+}
+
+static int exynos_cpufreq_remove(struct platform_device *pdev)
+{
+	cpufreq_unregister_driver(&exynos_driver);
+	opp_free_cpufreq_table(dvfs_info->dev, &dvfs_info->freq_table);
+	return 0;
+}
+
+static struct platform_driver exynos_cpufreq_platdrv = {
+	.driver = {
+		.name	= "exynos5440-cpufreq",
+		.owner	= THIS_MODULE,
+		.of_match_table = exynos_cpufreq_match,
+	},
+	.probe		= exynos_cpufreq_probe,
+	.remove		= exynos_cpufreq_remove,
+};
+module_platform_driver(exynos_cpufreq_platdrv);
+
+MODULE_AUTHOR("Amit Daniel Kachhap <amit.daniel@samsung.com>");
+MODULE_DESCRIPTION("Exynos5440 cpufreq driver");
+MODULE_LICENSE("GPL");
-- 
1.7.1

[PATCH V6 1/4] cpufreq: exynos: Add cpufreq driver for exynos5440

[Viresh Kumar]

On 8 April 2013 13:47, Amit Daniel Kachhap <amit.daniel@samsung.com> wrote:

> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
> index f3f3b14..bce2195 100644
> --- a/drivers/cpufreq/Kconfig.arm
> +++ b/drivers/cpufreq/Kconfig.arm
> @@ -42,6 +42,15 @@ config ARM_EXYNOS5250_CPUFREQ
>           This adds the CPUFreq driver for Samsung EXYNOS5250
>           SoC.
>
> +config ARM_EXYNOS5440_CPUFREQ
> +       def_bool SOC_EXYNOS5440
> +       depends on HAVE_CLK && PM_OPP && OF

Don't you need a depend on your Soc or mach or arch? Don't send another
version for this now.. Just send a new patch over this patchset.

> diff --git a/drivers/cpufreq/exynos5440-cpufreq.c b/drivers/cpufreq/exynos5440-cpufreq.c

> +static int exynos_target(struct cpufreq_policy *policy,
> +                         unsigned int target_freq,
> +                         unsigned int relation)
> +{
> +       unsigned int index, tmp;
> +       int ret = 0, i;
> +       struct cpufreq_frequency_table *freq_table = dvfs_info->freq_table;
> +
> +       mutex_lock(&cpufreq_lock);
> +       freqs.old = dvfs_info->cur_frequency;
> +
> +       ret = cpufreq_frequency_table_target(policy, freq_table,
> +                                          target_freq, relation, &index);
> +       if (ret)
> +               goto out;
> +

Move freqs.old = *** here.

> +       freqs.new = freq_table[index].frequency;
> +       freqs.cpu = policy->cpu;

You don't need this. Below call takes care of it.

Rest is fine.. Just resend this patch with all above issues fixed and i will Ack
it without any further reviews :)

Don't wait for few days for doing this, send it right now. :)

[PATCH V6 1/4] cpufreq: exynos: Add cpufreq driver for exynos5440

[Viresh Kumar]

On 8 April 2013 14:17, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> On 8 April 2013 13:47, Amit Daniel Kachhap <amit.daniel@samsung.com> wrote:
>
>> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
>> index f3f3b14..bce2195 100644
>> --- a/drivers/cpufreq/Kconfig.arm
>> +++ b/drivers/cpufreq/Kconfig.arm
>> @@ -42,6 +42,15 @@ config ARM_EXYNOS5250_CPUFREQ
>>           This adds the CPUFreq driver for Samsung EXYNOS5250
>>           SoC.
>>
>> +config ARM_EXYNOS5440_CPUFREQ
>> +       def_bool SOC_EXYNOS5440
>> +       depends on HAVE_CLK && PM_OPP && OF
>
> Don't you need a depend on your Soc or mach or arch? Don't send another
> version for this now.. Just send a new patch over this patchset.

Sorry, i overlooked def_bool... This comments stands invalid.

[RESEND PATCH V6 1/4] cpufreq: exynos: Add cpufreq driver for exynos5440

[Amit Daniel Kachhap]

This patch adds dvfs support for exynos5440 SOC. This soc has 4 cores and
they scale at same frequency. The nature of exynos5440 clock controller is
different from previous exynos controllers so not using the common exynos
cpufreq framework. The major difference being interrupt notification for
frequency change. Also, OPP library is used for device tree parsing to get
different parameters like frequency, voltage etc. Since the opp library sorts
the frequency table in ascending order so they are again re-arranged in
descending order. This will have one-to-one mapping with the clock controller
state management logic.

Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
---

Re-sending this patch with a minor comment from Viresh about the correct usage
of cpufreq_notify_transition API. 

 .../bindings/cpufreq/cpufreq-exynos5440.txt        |   28 ++
 drivers/cpufreq/Kconfig.arm                        |    9 +
 drivers/cpufreq/Makefile                           |    1 +
 drivers/cpufreq/exynos5440-cpufreq.c               |  478 ++++++++++++++++++++
 4 files changed, 516 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt
 create mode 100644 drivers/cpufreq/exynos5440-cpufreq.c

diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt
new file mode 100644
index 0000000..caff1a5
--- /dev/null
+++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt
@@ -0,0 +1,28 @@
+
+Exynos5440 cpufreq driver
+-------------------
+
+Exynos5440 SoC cpufreq driver for CPU frequency scaling.
+
+Required properties:
+- interrupts: Interrupt to know the completion of cpu frequency change.
+- operating-points: Table of frequencies and voltage CPU could be transitioned into,
+	in the decreasing order. Frequency should be in KHz units and voltage
+	should be in microvolts.
+
+Optional properties:
+- clock-latency: Clock monitor latency in microsecond.
+
+All the required listed above must be defined under node cpufreq.
+
+Example:
+--------
+	cpufreq at 160000 {
+		compatible = "samsung,exynos5440-cpufreq";
+		reg = <0x160000 0x1000>;
+		interrupts = <0 57 0>;
+		operating-points = <
+				1000000 975000
+				800000  925000>;
+		clock-latency = <100000>;
+	};
diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index f3f3b14..bce2195 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -42,6 +42,15 @@ config ARM_EXYNOS5250_CPUFREQ
 	  This adds the CPUFreq driver for Samsung EXYNOS5250
 	  SoC.
 
+config ARM_EXYNOS5440_CPUFREQ
+	def_bool SOC_EXYNOS5440
+	depends on HAVE_CLK && PM_OPP && OF
+	help
+	  This adds the CPUFreq driver for Samsung EXYNOS5440
+	  SoC. The nature of exynos5440 clock controller is
+	  different than previous exynos controllers so not using
+	  the common exynos framework.
+
 config ARM_HIGHBANK_CPUFREQ
 	tristate "Calxeda Highbank-based"
 	depends on ARCH_HIGHBANK
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 5db1f1f..6ad0b91 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -56,6 +56,7 @@ obj-$(CONFIG_ARM_EXYNOS_CPUFREQ)	+= exynos-cpufreq.o
 obj-$(CONFIG_ARM_EXYNOS4210_CPUFREQ)	+= exynos4210-cpufreq.o
 obj-$(CONFIG_ARM_EXYNOS4X12_CPUFREQ)	+= exynos4x12-cpufreq.o
 obj-$(CONFIG_ARM_EXYNOS5250_CPUFREQ)	+= exynos5250-cpufreq.o
+obj-$(CONFIG_ARM_EXYNOS5440_CPUFREQ)	+= exynos5440-cpufreq.o
 obj-$(CONFIG_ARM_HIGHBANK_CPUFREQ)	+= highbank-cpufreq.o
 obj-$(CONFIG_ARM_IMX6Q_CPUFREQ)		+= imx6q-cpufreq.o
 obj-$(CONFIG_ARM_INTEGRATOR)		+= integrator-cpufreq.o
diff --git a/drivers/cpufreq/exynos5440-cpufreq.c b/drivers/cpufreq/exynos5440-cpufreq.c
new file mode 100644
index 0000000..ead7ed4
--- /dev/null
+++ b/drivers/cpufreq/exynos5440-cpufreq.c
@@ -0,0 +1,478 @@
+/*
+ * Copyright (c) 2013 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * Amit Daniel Kachhap <amit.daniel@samsung.com>
+ *
+ * EXYNOS5440 - 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/clk.h>
+#include <linux/cpu.h>
+#include <linux/cpufreq.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/opp.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+/* Register definitions */
+#define XMU_DVFS_CTRL		0x0060
+#define XMU_PMU_P0_7		0x0064
+#define XMU_C0_3_PSTATE		0x0090
+#define XMU_P_LIMIT		0x00a0
+#define XMU_P_STATUS		0x00a4
+#define XMU_PMUEVTEN		0x00d0
+#define XMU_PMUIRQEN		0x00d4
+#define XMU_PMUIRQ		0x00d8
+
+/* PMU mask and shift definations */
+#define P_VALUE_MASK		0x7
+
+#define XMU_DVFS_CTRL_EN_SHIFT	0
+
+#define P0_7_CPUCLKDEV_SHIFT	21
+#define P0_7_CPUCLKDEV_MASK	0x7
+#define P0_7_ATBCLKDEV_SHIFT	18
+#define P0_7_ATBCLKDEV_MASK	0x7
+#define P0_7_CSCLKDEV_SHIFT	15
+#define P0_7_CSCLKDEV_MASK	0x7
+#define P0_7_CPUEMA_SHIFT	28
+#define P0_7_CPUEMA_MASK	0xf
+#define P0_7_L2EMA_SHIFT	24
+#define P0_7_L2EMA_MASK		0xf
+#define P0_7_VDD_SHIFT		8
+#define P0_7_VDD_MASK		0x7f
+#define P0_7_FREQ_SHIFT		0
+#define P0_7_FREQ_MASK		0xff
+
+#define C0_3_PSTATE_VALID_SHIFT	8
+#define C0_3_PSTATE_CURR_SHIFT	4
+#define C0_3_PSTATE_NEW_SHIFT	0
+
+#define PSTATE_CHANGED_EVTEN_SHIFT	0
+
+#define PSTATE_CHANGED_IRQEN_SHIFT	0
+
+#define PSTATE_CHANGED_SHIFT		0
+
+/* some constant values for clock divider calculation */
+#define CPU_DIV_FREQ_MAX	500
+#define CPU_DBG_FREQ_MAX	375
+#define CPU_ATB_FREQ_MAX	500
+
+#define PMIC_LOW_VOLT		0x30
+#define PMIC_HIGH_VOLT		0x28
+
+#define CPUEMA_HIGH		0x2
+#define CPUEMA_MID		0x4
+#define CPUEMA_LOW		0x7
+
+#define L2EMA_HIGH		0x1
+#define L2EMA_MID		0x3
+#define L2EMA_LOW		0x4
+
+#define DIV_TAB_MAX	2
+/* frequency unit is 20MHZ */
+#define FREQ_UNIT	20
+#define MAX_VOLTAGE	1550000 /* In microvolt */
+#define VOLTAGE_STEP	12500	/* In microvolt */
+
+#define CPUFREQ_NAME		"exynos5440_dvfs"
+#define DEF_TRANS_LATENCY	100000
+
+enum cpufreq_level_index {
+	L0, L1, L2, L3, L4,
+	L5, L6, L7, L8, L9,
+};
+#define CPUFREQ_LEVEL_END	(L7 + 1)
+
+struct exynos_dvfs_data {
+	void __iomem *base;
+	struct resource *mem;
+	int irq;
+	struct clk *cpu_clk;
+	unsigned int cur_frequency;
+	unsigned int latency;
+	struct cpufreq_frequency_table *freq_table;
+	unsigned int freq_count;
+	struct device *dev;
+	bool dvfs_enabled;
+	struct work_struct irq_work;
+};
+
+static struct exynos_dvfs_data *dvfs_info;
+static DEFINE_MUTEX(cpufreq_lock);
+static struct cpufreq_freqs freqs;
+
+static int init_div_table(void)
+{
+	struct cpufreq_frequency_table *freq_tbl = dvfs_info->freq_table;
+	unsigned int tmp, clk_div, ema_div, freq, volt_id;
+	int i = 0;
+	struct opp *opp;
+
+	for (i = 0; freq_tbl[i].frequency != CPUFREQ_TABLE_END; i++) {
+
+		opp = opp_find_freq_exact(dvfs_info->dev,
+					freq_tbl[i].frequency * 1000, true);
+		if (IS_ERR(opp)) {
+			dev_err(dvfs_info->dev,
+				"failed to find valid OPP for %u KHZ\n",
+				freq_tbl[i].frequency);
+			return PTR_ERR(opp);
+		}
+
+		freq = freq_tbl[i].frequency / 1000; /* In MHZ */
+		clk_div = ((freq / CPU_DIV_FREQ_MAX) & P0_7_CPUCLKDEV_MASK)
+					<< P0_7_CPUCLKDEV_SHIFT;
+		clk_div |= ((freq / CPU_ATB_FREQ_MAX) & P0_7_ATBCLKDEV_MASK)
+					<< P0_7_ATBCLKDEV_SHIFT;
+		clk_div |= ((freq / CPU_DBG_FREQ_MAX) & P0_7_CSCLKDEV_MASK)
+					<< P0_7_CSCLKDEV_SHIFT;
+
+		/* Calculate EMA */
+		volt_id = opp_get_voltage(opp);
+		volt_id = (MAX_VOLTAGE - volt_id) / VOLTAGE_STEP;
+		if (volt_id < PMIC_HIGH_VOLT) {
+			ema_div = (CPUEMA_HIGH << P0_7_CPUEMA_SHIFT) |
+				(L2EMA_HIGH << P0_7_L2EMA_SHIFT);
+		} else if (volt_id > PMIC_LOW_VOLT) {
+			ema_div = (CPUEMA_LOW << P0_7_CPUEMA_SHIFT) |
+				(L2EMA_LOW << P0_7_L2EMA_SHIFT);
+		} else {
+			ema_div = (CPUEMA_MID << P0_7_CPUEMA_SHIFT) |
+				(L2EMA_MID << P0_7_L2EMA_SHIFT);
+		}
+
+		tmp = (clk_div | ema_div | (volt_id << P0_7_VDD_SHIFT)
+			| ((freq / FREQ_UNIT) << P0_7_FREQ_SHIFT));
+
+		__raw_writel(tmp, dvfs_info->base + XMU_PMU_P0_7 + 4 * i);
+	}
+
+	return 0;
+}
+
+static void exynos_enable_dvfs(void)
+{
+	unsigned int tmp, i, cpu;
+	struct cpufreq_frequency_table *freq_table = dvfs_info->freq_table;
+	/* Disable DVFS */
+	__raw_writel(0,	dvfs_info->base + XMU_DVFS_CTRL);
+
+	/* Enable PSTATE Change Event */
+	tmp = __raw_readl(dvfs_info->base + XMU_PMUEVTEN);
+	tmp |= (1 << PSTATE_CHANGED_EVTEN_SHIFT);
+	 __raw_writel(tmp, dvfs_info->base + XMU_PMUEVTEN);
+
+	/* Enable PSTATE Change IRQ */
+	tmp = __raw_readl(dvfs_info->base + XMU_PMUIRQEN);
+	tmp |= (1 << PSTATE_CHANGED_IRQEN_SHIFT);
+	 __raw_writel(tmp, dvfs_info->base + XMU_PMUIRQEN);
+
+	/* Set initial performance index */
+	for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++)
+		if (freq_table[i].frequency == dvfs_info->cur_frequency)
+			break;
+
+	if (freq_table[i].frequency == CPUFREQ_TABLE_END) {
+		dev_crit(dvfs_info->dev, "Boot up frequency not supported\n");
+		/* Assign the highest frequency */
+		i = 0;
+		dvfs_info->cur_frequency = freq_table[i].frequency;
+	}
+
+	dev_info(dvfs_info->dev, "Setting dvfs initial frequency = %uKHZ",
+						dvfs_info->cur_frequency);
+
+	for (cpu = 0; cpu < CONFIG_NR_CPUS; cpu++) {
+		tmp = __raw_readl(dvfs_info->base + XMU_C0_3_PSTATE + cpu * 4);
+		tmp &= ~(P_VALUE_MASK << C0_3_PSTATE_NEW_SHIFT);
+		tmp |= (i << C0_3_PSTATE_NEW_SHIFT);
+		__raw_writel(tmp, dvfs_info->base + XMU_C0_3_PSTATE + cpu * 4);
+	}
+
+	/* Enable DVFS */
+	__raw_writel(1 << XMU_DVFS_CTRL_EN_SHIFT,
+				dvfs_info->base + XMU_DVFS_CTRL);
+}
+
+static int exynos_verify_speed(struct cpufreq_policy *policy)
+{
+	return cpufreq_frequency_table_verify(policy,
+					      dvfs_info->freq_table);
+}
+
+static unsigned int exynos_getspeed(unsigned int cpu)
+{
+	return dvfs_info->cur_frequency;
+}
+
+static int exynos_target(struct cpufreq_policy *policy,
+			  unsigned int target_freq,
+			  unsigned int relation)
+{
+	unsigned int index, tmp;
+	int ret = 0, i;
+	struct cpufreq_frequency_table *freq_table = dvfs_info->freq_table;
+
+	mutex_lock(&cpufreq_lock);
+
+	ret = cpufreq_frequency_table_target(policy, freq_table,
+					   target_freq, relation, &index);
+	if (ret)
+		goto out;
+
+	freqs.old = dvfs_info->cur_frequency;
+	freqs.new = freq_table[index].frequency;
+
+	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
+
+	/* Set the target frequency in all C0_3_PSTATE register */
+	for_each_cpu(i, policy->cpus) {
+		tmp = __raw_readl(dvfs_info->base + XMU_C0_3_PSTATE + i * 4);
+		tmp &= ~(P_VALUE_MASK << C0_3_PSTATE_NEW_SHIFT);
+		tmp |= (index << C0_3_PSTATE_NEW_SHIFT);
+
+		__raw_writel(tmp, dvfs_info->base + XMU_C0_3_PSTATE + i * 4);
+	}
+out:
+	mutex_unlock(&cpufreq_lock);
+	return ret;
+}
+
+static void exynos_cpufreq_work(struct work_struct *work)
+{
+	unsigned int cur_pstate, index;
+	struct cpufreq_policy *policy = cpufreq_cpu_get(0); /* boot CPU */
+	struct cpufreq_frequency_table *freq_table = dvfs_info->freq_table;
+
+	/* Ensure we can access cpufreq structures */
+	if (unlikely(dvfs_info->dvfs_enabled == false))
+		goto skip_work;
+
+	mutex_lock(&cpufreq_lock);
+	freqs.old = dvfs_info->cur_frequency;
+
+	cur_pstate = __raw_readl(dvfs_info->base + XMU_P_STATUS);
+	if (cur_pstate >> C0_3_PSTATE_VALID_SHIFT & 0x1)
+		index = (cur_pstate >> C0_3_PSTATE_CURR_SHIFT) & P_VALUE_MASK;
+	else
+		index = (cur_pstate >> C0_3_PSTATE_NEW_SHIFT) & P_VALUE_MASK;
+
+	if (likely(index < dvfs_info->freq_count)) {
+		freqs.new = freq_table[index].frequency;
+		dvfs_info->cur_frequency = freqs.new;
+	} else {
+		dev_crit(dvfs_info->dev, "New frequency out of range\n");
+		freqs.new = dvfs_info->cur_frequency;
+	}
+	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
+
+	cpufreq_cpu_put(policy);
+	mutex_unlock(&cpufreq_lock);
+skip_work:
+	enable_irq(dvfs_info->irq);
+}
+
+static irqreturn_t exynos_cpufreq_irq(int irq, void *id)
+{
+	unsigned int tmp;
+
+	tmp = __raw_readl(dvfs_info->base + XMU_PMUIRQ);
+	if (tmp >> PSTATE_CHANGED_SHIFT & 0x1) {
+		__raw_writel(tmp, dvfs_info->base + XMU_PMUIRQ);
+		disable_irq_nosync(irq);
+		schedule_work(&dvfs_info->irq_work);
+	}
+	return IRQ_HANDLED;
+}
+
+static void exynos_sort_descend_freq_table(void)
+{
+	struct cpufreq_frequency_table *freq_tbl = dvfs_info->freq_table;
+	int i = 0, index;
+	unsigned int tmp_freq;
+	/*
+	 * Exynos5440 clock controller state logic expects the cpufreq table to
+	 * be in descending order. But the OPP library constructs the table in
+	 * ascending order. So to make the table descending we just need to
+	 * swap the i element with the N - i element.
+	 */
+	for (i = 0; i < dvfs_info->freq_count / 2; i++) {
+		index = dvfs_info->freq_count - i - 1;
+		tmp_freq = freq_tbl[i].frequency;
+		freq_tbl[i].frequency = freq_tbl[index].frequency;
+		freq_tbl[index].frequency = tmp_freq;
+	}
+}
+
+static int exynos_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+	int ret;
+
+	ret = cpufreq_frequency_table_cpuinfo(policy, dvfs_info->freq_table);
+	if (ret) {
+		dev_err(dvfs_info->dev, "Invalid frequency table: %d\n", ret);
+		return ret;
+	}
+
+	policy->cur = dvfs_info->cur_frequency;
+	policy->cpuinfo.transition_latency = dvfs_info->latency;
+	cpumask_setall(policy->cpus);
+
+	cpufreq_frequency_table_get_attr(dvfs_info->freq_table, policy->cpu);
+
+	return 0;
+}
+
+static struct cpufreq_driver exynos_driver = {
+	.flags		= CPUFREQ_STICKY,
+	.verify		= exynos_verify_speed,
+	.target		= exynos_target,
+	.get		= exynos_getspeed,
+	.init		= exynos_cpufreq_cpu_init,
+	.name		= CPUFREQ_NAME,
+};
+
+static const struct of_device_id exynos_cpufreq_match[] = {
+	{
+		.compatible = "samsung,exynos5440-cpufreq",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, exynos_cpufreq_match);
+
+static int exynos_cpufreq_probe(struct platform_device *pdev)
+{
+	int ret = -EINVAL;
+	struct device_node *np;
+	struct resource res;
+
+	np =  pdev->dev.of_node;
+	if (!np)
+		return -ENODEV;
+
+	dvfs_info = devm_kzalloc(&pdev->dev, sizeof(*dvfs_info), GFP_KERNEL);
+	if (!dvfs_info) {
+		ret = -ENOMEM;
+		goto err_put_node;
+	}
+
+	dvfs_info->dev = &pdev->dev;
+
+	ret = of_address_to_resource(np, 0, &res);
+	if (ret)
+		goto err_put_node;
+
+	dvfs_info->base = devm_ioremap_resource(dvfs_info->dev, &res);
+	if (IS_ERR(dvfs_info->base)) {
+		ret = PTR_ERR(dvfs_info->base);
+		goto err_put_node;
+	}
+
+	dvfs_info->irq = irq_of_parse_and_map(np, 0);
+	if (!dvfs_info->irq) {
+		dev_err(dvfs_info->dev, "No cpufreq irq found\n");
+		ret = -ENODEV;
+		goto err_put_node;
+	}
+
+	ret = of_init_opp_table(dvfs_info->dev);
+	if (ret) {
+		dev_err(dvfs_info->dev, "failed to init OPP table: %d\n", ret);
+		goto err_put_node;
+	}
+
+	ret = opp_init_cpufreq_table(dvfs_info->dev, &dvfs_info->freq_table);
+	if (ret) {
+		dev_err(dvfs_info->dev,
+			"failed to init cpufreq table: %d\n", ret);
+		goto err_put_node;
+	}
+	dvfs_info->freq_count = opp_get_opp_count(dvfs_info->dev);
+	exynos_sort_descend_freq_table();
+
+	if (of_property_read_u32(np, "clock-latency", &dvfs_info->latency))
+		dvfs_info->latency = DEF_TRANS_LATENCY;
+
+	dvfs_info->cpu_clk = devm_clk_get(dvfs_info->dev, "armclk");
+	if (IS_ERR(dvfs_info->cpu_clk)) {
+		dev_err(dvfs_info->dev, "Failed to get cpu clock\n");
+		ret = PTR_ERR(dvfs_info->cpu_clk);
+		goto err_free_table;
+	}
+
+	dvfs_info->cur_frequency = clk_get_rate(dvfs_info->cpu_clk);
+	if (!dvfs_info->cur_frequency) {
+		dev_err(dvfs_info->dev, "Failed to get clock rate\n");
+		ret = -EINVAL;
+		goto err_free_table;
+	}
+	dvfs_info->cur_frequency /= 1000;
+
+	INIT_WORK(&dvfs_info->irq_work, exynos_cpufreq_work);
+	ret = devm_request_irq(dvfs_info->dev, dvfs_info->irq,
+				exynos_cpufreq_irq, IRQF_TRIGGER_NONE,
+				CPUFREQ_NAME, dvfs_info);
+	if (ret) {
+		dev_err(dvfs_info->dev, "Failed to register IRQ\n");
+		goto err_free_table;
+	}
+
+	ret = init_div_table();
+	if (ret) {
+		dev_err(dvfs_info->dev, "Failed to initialise div table\n");
+		goto err_free_table;
+	}
+
+	exynos_enable_dvfs();
+	ret = cpufreq_register_driver(&exynos_driver);
+	if (ret) {
+		dev_err(dvfs_info->dev,
+			"%s: failed to register cpufreq driver\n", __func__);
+		goto err_free_table;
+	}
+
+	of_node_put(np);
+	dvfs_info->dvfs_enabled = true;
+	return 0;
+
+err_free_table:
+	opp_free_cpufreq_table(dvfs_info->dev, &dvfs_info->freq_table);
+err_put_node:
+	of_node_put(np);
+	dev_err(dvfs_info->dev, "%s: failed initialization\n", __func__);
+	return ret;
+}
+
+static int exynos_cpufreq_remove(struct platform_device *pdev)
+{
+	cpufreq_unregister_driver(&exynos_driver);
+	opp_free_cpufreq_table(dvfs_info->dev, &dvfs_info->freq_table);
+	return 0;
+}
+
+static struct platform_driver exynos_cpufreq_platdrv = {
+	.driver = {
+		.name	= "exynos5440-cpufreq",
+		.owner	= THIS_MODULE,
+		.of_match_table = exynos_cpufreq_match,
+	},
+	.probe		= exynos_cpufreq_probe,
+	.remove		= exynos_cpufreq_remove,
+};
+module_platform_driver(exynos_cpufreq_platdrv);
+
+MODULE_AUTHOR("Amit Daniel Kachhap <amit.daniel@samsung.com>");
+MODULE_DESCRIPTION("Exynos5440 cpufreq driver");
+MODULE_LICENSE("GPL");
-- 
1.7.1

[RESEND PATCH V6 1/4] cpufreq: exynos: Add cpufreq driver for exynos5440

[Nishanth Menon]

Hi,
On Mon, Apr 8, 2013 at 4:57 AM, Amit Daniel Kachhap
<amit.daniel@samsung.com> wrote:
> +
> +static int init_div_table(void)
> +{
> +       struct cpufreq_frequency_table *freq_tbl = dvfs_info->freq_table;
> +       unsigned int tmp, clk_div, ema_div, freq, volt_id;
> +       int i = 0;
> +       struct opp *opp;
> +
> +       for (i = 0; freq_tbl[i].frequency != CPUFREQ_TABLE_END; i++) {
> +
> +               opp = opp_find_freq_exact(dvfs_info->dev,
> +                                       freq_tbl[i].frequency * 1000, true);
> +               if (IS_ERR(opp)) {
> +                       dev_err(dvfs_info->dev,
> +                               "failed to find valid OPP for %u KHZ\n",
> +                               freq_tbl[i].frequency);
> +                       return PTR_ERR(opp);
> +               }
please use RCU read locks.

> +
> +               freq = freq_tbl[i].frequency / 1000; /* In MHZ */
> +               clk_div = ((freq / CPU_DIV_FREQ_MAX) & P0_7_CPUCLKDEV_MASK)
> +                                       << P0_7_CPUCLKDEV_SHIFT;
> +               clk_div |= ((freq / CPU_ATB_FREQ_MAX) & P0_7_ATBCLKDEV_MASK)
> +                                       << P0_7_ATBCLKDEV_SHIFT;
> +               clk_div |= ((freq / CPU_DBG_FREQ_MAX) & P0_7_CSCLKDEV_MASK)
> +                                       << P0_7_CSCLKDEV_SHIFT;
> +
> +               /* Calculate EMA */
> +               volt_id = opp_get_voltage(opp);
Please use RCU read locks as documented for OPP library.

Regards,
Nishanth Menon

[RESEND PATCH V6 1/4] cpufreq: exynos: Add cpufreq driver for exynos5440

[Rafael J. Wysocki]

On Thursday, April 11, 2013 06:23:52 PM Nishanth Menon wrote:
> Hi,
> On Mon, Apr 8, 2013 at 4:57 AM, Amit Daniel Kachhap
> <amit.daniel@samsung.com> wrote:
> > +
> > +static int init_div_table(void)
> > +{
> > +       struct cpufreq_frequency_table *freq_tbl = dvfs_info->freq_table;
> > +       unsigned int tmp, clk_div, ema_div, freq, volt_id;
> > +       int i = 0;
> > +       struct opp *opp;
> > +
> > +       for (i = 0; freq_tbl[i].frequency != CPUFREQ_TABLE_END; i++) {
> > +
> > +               opp = opp_find_freq_exact(dvfs_info->dev,
> > +                                       freq_tbl[i].frequency * 1000, true);
> > +               if (IS_ERR(opp)) {
> > +                       dev_err(dvfs_info->dev,
> > +                               "failed to find valid OPP for %u KHZ\n",
> > +                               freq_tbl[i].frequency);
> > +                       return PTR_ERR(opp);
> > +               }
> please use RCU read locks.
> 
> > +
> > +               freq = freq_tbl[i].frequency / 1000; /* In MHZ */
> > +               clk_div = ((freq / CPU_DIV_FREQ_MAX) & P0_7_CPUCLKDEV_MASK)
> > +                                       << P0_7_CPUCLKDEV_SHIFT;
> > +               clk_div |= ((freq / CPU_ATB_FREQ_MAX) & P0_7_ATBCLKDEV_MASK)
> > +                                       << P0_7_ATBCLKDEV_SHIFT;
> > +               clk_div |= ((freq / CPU_DBG_FREQ_MAX) & P0_7_CSCLKDEV_MASK)
> > +                                       << P0_7_CSCLKDEV_SHIFT;
> > +
> > +               /* Calculate EMA */
> > +               volt_id = opp_get_voltage(opp);
> Please use RCU read locks as documented for OPP library.

Argh.  I overlooked that and the series has been applied already.  Care to send
a fix against linux-pm.git/linux-next?

Rafael


-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.

[RESEND PATCH V6 1/4] cpufreq: exynos: Add cpufreq driver for exynos5440

[amit daniel kachhap]

Hi Rafael,

On Fri, Apr 12, 2013 at 4:49 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> On Thursday, April 11, 2013 06:23:52 PM Nishanth Menon wrote:
>> Hi,
>> On Mon, Apr 8, 2013 at 4:57 AM, Amit Daniel Kachhap
>> <amit.daniel@samsung.com> wrote:
>> > +
>> > +static int init_div_table(void)
>> > +{
>> > +       struct cpufreq_frequency_table *freq_tbl = dvfs_info->freq_table;
>> > +       unsigned int tmp, clk_div, ema_div, freq, volt_id;
>> > +       int i = 0;
>> > +       struct opp *opp;
>> > +
>> > +       for (i = 0; freq_tbl[i].frequency != CPUFREQ_TABLE_END; i++) {
>> > +
>> > +               opp = opp_find_freq_exact(dvfs_info->dev,
>> > +                                       freq_tbl[i].frequency * 1000, true);
>> > +               if (IS_ERR(opp)) {
>> > +                       dev_err(dvfs_info->dev,
>> > +                               "failed to find valid OPP for %u KHZ\n",
>> > +                               freq_tbl[i].frequency);
>> > +                       return PTR_ERR(opp);
>> > +               }
>> please use RCU read locks.
>>
>> > +
>> > +               freq = freq_tbl[i].frequency / 1000; /* In MHZ */
>> > +               clk_div = ((freq / CPU_DIV_FREQ_MAX) & P0_7_CPUCLKDEV_MASK)
>> > +                                       << P0_7_CPUCLKDEV_SHIFT;
>> > +               clk_div |= ((freq / CPU_ATB_FREQ_MAX) & P0_7_ATBCLKDEV_MASK)
>> > +                                       << P0_7_ATBCLKDEV_SHIFT;
>> > +               clk_div |= ((freq / CPU_DBG_FREQ_MAX) & P0_7_CSCLKDEV_MASK)
>> > +                                       << P0_7_CSCLKDEV_SHIFT;
>> > +
>> > +               /* Calculate EMA */
>> > +               volt_id = opp_get_voltage(opp);
>> Please use RCU read locks as documented for OPP library.
>
> Argh.  I overlooked that and the series has been applied already.  Care to send
> a fix against linux-pm.git/linux-next?

Will submit a patch with RCU lock changes.

Thanks,
Amit Daniel
>
> Rafael
>
>
> --
> I speak only for myself.
> Rafael J. Wysocki, Intel Open Source Technology Center.
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH V6 1/4] cpufreq: exynos: Add cpufreq driver for exynos5440

[amit daniel kachhap]

On Mon, Apr 8, 2013 at 2:46 PM, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> On 8 April 2013 14:17, Viresh Kumar <viresh.kumar@linaro.org> wrote:
>> On 8 April 2013 13:47, Amit Daniel Kachhap <amit.daniel@samsung.com> wrote:
>>
>>> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
>>> index f3f3b14..bce2195 100644
>>> --- a/drivers/cpufreq/Kconfig.arm
>>> +++ b/drivers/cpufreq/Kconfig.arm
>>> @@ -42,6 +42,15 @@ config ARM_EXYNOS5250_CPUFREQ
>>>           This adds the CPUFreq driver for Samsung EXYNOS5250
>>>           SoC.
>>>
>>> +config ARM_EXYNOS5440_CPUFREQ
>>> +       def_bool SOC_EXYNOS5440
>>> +       depends on HAVE_CLK && PM_OPP && OF
>>
>> Don't you need a depend on your Soc or mach or arch? Don't send another
>> version for this now.. Just send a new patch over this patchset.
>
> Sorry, i overlooked def_bool... This comments stands invalid.
Ok, I resend this patch addressing all comments.

Thanks,
Amit
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH V6 2/4] cpufreq: exynos: Remove error return even if no soc is found

[Amit Daniel Kachhap]

This patch helps to have single binary for exynos5440 and previous
exynos soc's. This change is needed for adding exynos5440 cpufreq driver
which does not uses exynos-cpufreq common file and adds it own driver.

Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
---
 drivers/cpufreq/exynos-cpufreq.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/cpufreq/exynos-cpufreq.c b/drivers/cpufreq/exynos-cpufreq.c
index c0c4ce5..475b4f6 100644
--- a/drivers/cpufreq/exynos-cpufreq.c
+++ b/drivers/cpufreq/exynos-cpufreq.c
@@ -294,7 +294,7 @@ static int __init exynos_cpufreq_init(void)
 	else if (soc_is_exynos5250())
 		ret = exynos5250_cpufreq_init(exynos_info);
 	else
-		pr_err("%s: CPU type not found\n", __func__);
+		return 0;
 
 	if (ret)
 		goto err_vdd_arm;
-- 
1.7.1

[PATCH V6 3/4] arm: exynos: Enable OPP library support for exynos5440

[Amit Daniel Kachhap]

The OPP library support is needed for exynos5440 cpu frequency
dynamic scaling driver.

Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
---
 arch/arm/mach-exynos/Kconfig |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-exynos/Kconfig b/arch/arm/mach-exynos/Kconfig
index 70f94c8..d5dde07 100644
--- a/arch/arm/mach-exynos/Kconfig
+++ b/arch/arm/mach-exynos/Kconfig
@@ -72,10 +72,12 @@ config SOC_EXYNOS5440
 	bool "SAMSUNG EXYNOS5440"
 	default y
 	depends on ARCH_EXYNOS5
+	select ARCH_HAS_OPP
 	select ARM_ARCH_TIMER
 	select AUTO_ZRELADDR
 	select PINCTRL
 	select PINCTRL_EXYNOS5440
+	select PM_OPP
 	help
 	  Enable EXYNOS5440 SoC support
 
-- 
1.7.1

[PATCH V6 4/4] arm: dts: Add cpufreq controller node for Exynos5440 SoC

[Amit Daniel Kachhap]

Add cpufreq controller device node for Exynos5440 SoC for passing
parameters like controller base address, interrupt and cpufreq
table. This node is added outside cpu0 as this driver is now a platform
driver and a new device structure is needed.

Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
---
 arch/arm/boot/dts/exynos5440.dtsi |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/arch/arm/boot/dts/exynos5440.dtsi b/arch/arm/boot/dts/exynos5440.dtsi
index 9a99755..94074ea 100644
--- a/arch/arm/boot/dts/exynos5440.dtsi
+++ b/arch/arm/boot/dts/exynos5440.dtsi
@@ -63,6 +63,18 @@
 
 	};
 
+	cpufreq at 160000 {
+		compatible = "samsung,exynos5440-cpufreq";
+		reg = <0x160000 0x1000>;
+		interrupts = <0 57 0>;
+		operating-points = <
+				/* KHz	  uV */
+				1200000 1025000
+				1000000 975000
+				800000  925000
+		>;
+	};
+
 	serial at B0000 {
 		compatible = "samsung,exynos4210-uart";
 		reg = <0xB0000 0x1000>;
-- 
1.7.1

[PATCH V6 0/4] cpufreq: exynos5440: support for cpufreq driver

[Viresh Kumar]

On 8 April 2013 13:47, Amit Daniel Kachhap <amit.daniel@samsung.com> wrote:
> Submitting the V6 version of exynos5440 cpufreq driver. This patchset addresses
> all the coding and design concerns raised especially by Viresh.
>
> Changes in V6:
> * Used cpufreq post-change notifier call back in case of failure as pointed by
>   Viresh.
> * Called cpufreq_frequency_table_cpuinfo before calling
>   cpufreq_frequency_table_get_attr as pointed by Viresh.
> * Used modified API cpufreq_notify_transition.
>
> Changes in V5:
> * Removed the unnecessary DT look up entry from mach-exynos5-dt.c.
> * Fixed all coding and comments issue raised by Viresh.
>
> Changes in V4:
> * Added dev_err logs instead of pr_err.
> * Used the devm_ioremap_resource API.
> * Implemented several coding guidelines and minor error comments from Sylwester,
>   Russell and Viresh.
>
> Changes in V3:
> * Converted the driver to probe based as suggested by Viresh. This is also
>   beneficial for multiplatform kernel.
> * Other coding guidelines related changes.
> * Moved the DT node outside cpu0 node as the driver is now a platform
>   driver.
>
> Changes in V2:
> * Added OPP library support to parse DT parameters.
> * Removed a hack to handle interrupts in bootup.
> * Implemented other review comments from Viresh and Inder.
>
> All these patches are dependent on Thomas Abraham common clock patches.
> (http://www.mail-archive.com/linux-samsung-soc at vger.kernel.org/msg15860.html)
> This whole patch series is based on Rafael tree.
> git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git bleeding-edge
>
> Amit Daniel Kachhap (4):
>   cpufreq: exynos: Add cpufreq driver for exynos5440
>   cpufreq: exynos: Remove error return even if no soc is found
>   arm: exynos: Enable OPP library support for exynos5440
>   arm: dts: Add cpufreq controller node for Exynos5440 SoC
>
>  .../bindings/cpufreq/cpufreq-exynos5440.txt        |   28 ++
>  arch/arm/boot/dts/exynos5440.dtsi                  |   12 +
>  arch/arm/mach-exynos/Kconfig                       |    2 +
>  drivers/cpufreq/Kconfig.arm                        |    9 +
>  drivers/cpufreq/Makefile                           |    1 +
>  drivers/cpufreq/exynos-cpufreq.c                   |    2 +-
>  drivers/cpufreq/exynos5440-cpufreq.c               |  479 ++++++++++++++++++++
>  7 files changed, 532 insertions(+), 1 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt
>  create mode 100644 drivers/cpufreq/exynos5440-cpufreq.c

With the resent of 1/4,

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>