[PATCH 2/2] devfreq: rockchip: support rk3399 dmc devfreq

[Lin Huang]

rk3399 do ddr frequency scaling use devfreq framework,
use simple_ondemand policy, and use rk3399 dfi controller
to get ddr busy time.

Signed-off-by: Lin Huang <hl@xxxxxxxxxxxxxx>
---
 drivers/devfreq/Kconfig               |   1 +
 drivers/devfreq/Makefile              |   1 +
 drivers/devfreq/rockchip/Kconfig      |   8 +
 drivers/devfreq/rockchip/Makefile     |   1 +
 drivers/devfreq/rockchip/rk3399_dmc.c | 327 ++++++++++++++++++++++++++++++++++
 5 files changed, 338 insertions(+)
 create mode 100644 drivers/devfreq/rockchip/Kconfig
 create mode 100644 drivers/devfreq/rockchip/Makefile
 create mode 100644 drivers/devfreq/rockchip/rk3399_dmc.c

diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
index 64281bb..acb2a57 100644
--- a/drivers/devfreq/Kconfig
+++ b/drivers/devfreq/Kconfig
@@ -99,5 +99,6 @@ config ARM_TEGRA_DEVFREQ
          operating frequencies and voltages with OPP support.
 
 source "drivers/devfreq/event/Kconfig"
+source "drivers/devfreq/rockchip/Kconfig"
 
 endif # PM_DEVFREQ
diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile
index 5134f9e..d844e23 100644
--- a/drivers/devfreq/Makefile
+++ b/drivers/devfreq/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_DEVFREQ_GOV_USERSPACE)	+= governor_userspace.o
 obj-$(CONFIG_ARM_EXYNOS4_BUS_DEVFREQ)	+= exynos/
 obj-$(CONFIG_ARM_EXYNOS5_BUS_DEVFREQ)	+= exynos/
 obj-$(CONFIG_ARM_TEGRA_DEVFREQ)		+= tegra-devfreq.o
+obj-$(CONFIG_ARCH_ROCKCHIP)		+= rockchip/
 
 # DEVFREQ Event Drivers
 obj-$(CONFIG_PM_DEVFREQ_EVENT)		+= event/
diff --git a/drivers/devfreq/rockchip/Kconfig b/drivers/devfreq/rockchip/Kconfig
new file mode 100644
index 0000000..ceb7f37
--- /dev/null
+++ b/drivers/devfreq/rockchip/Kconfig
@@ -0,0 +1,8 @@
+config ARM_RK3399_DMC_DEVFREQ
+	tristate "ARM RK3399 DMC DEVFREQ Driver"
+	depends on ARCH_ROCKCHIP
+	select PM_OPP
+	select DEVFREQ_GOV_SIMPLE_ONDEMAND
+	help
+	  This adds the DEVFREQ driver for the RK3399 dmc. It sets the frequency
+	  for the memory controller and reads the usage counts from hardware.
diff --git a/drivers/devfreq/rockchip/Makefile b/drivers/devfreq/rockchip/Makefile
new file mode 100644
index 0000000..c62c105
--- /dev/null
+++ b/drivers/devfreq/rockchip/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_ARM_RK3399_DMC_DEVFREQ)	+= rk3399_dmc.o
diff --git a/drivers/devfreq/rockchip/rk3399_dmc.c b/drivers/devfreq/rockchip/rk3399_dmc.c
new file mode 100644
index 0000000..6bf4230
--- /dev/null
+++ b/drivers/devfreq/rockchip/rk3399_dmc.c
@@ -0,0 +1,327 @@
+/*
+ * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/devfreq.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/rwsem.h>
+#include <linux/suspend.h>
+#include <linux/syscore_ops.h>
+#include <soc/rockchip/rk3399-dmc-clk.h>
+
+#define RK3399_DMC_NUM_CH	2
+
+/* DDRMON_CTRL */
+#define DDRMON_CTRL	0x04
+#define LPDDR4_EN	(1 << 4)
+#define HARDWARE_EN	(1 << 3)
+#define LPDDR3_EN	(1 << 2)
+#define SOFTWARE_EN	(1 << 1)
+#define TIME_CNT_EN	(1 << 0)
+
+#define DDRMON_CH0_COUNT_NUM		0x28
+#define DDRMON_CH0_DFI_ACCESS_NUM	0x2c
+#define DDRMON_CH1_COUNT_NUM		0x3c
+#define DDRMON_CH1_DFI_ACCESS_NUM	0x40
+
+struct dmc_usage {
+	u32 access;
+	u32 total;
+};
+
+struct rk3399_dmcfreq {
+	struct device *clk_dev;
+	struct devfreq *devfreq;
+	struct devfreq_simple_ondemand_data ondemand_data;
+	struct clk *dmc_clk;
+	struct regulator *vdd_logic;
+	struct dmc_usage ch_usage[RK3399_DMC_NUM_CH];
+	struct rk3399_dmcclk *dmc_data;
+	struct mutex lock;
+	unsigned long rate, target_rate;
+	unsigned long volt, target_volt;
+};
+
+static struct rk3399_dmcfreq dmcfreq;
+
+static int rk3399_dmcfreq_target(struct device *dev, unsigned long *freq,
+				 u32 flags)
+{
+	struct dev_pm_opp *opp;
+	unsigned long old_clk_rate = dmcfreq.rate;
+	unsigned long target_volt, target_rate;
+	int err;
+
+	rcu_read_lock();
+	opp = devfreq_recommended_opp(dev, freq, flags);
+	if (IS_ERR(opp)) {
+		rcu_read_unlock();
+		return PTR_ERR(opp);
+	}
+	target_rate = dev_pm_opp_get_freq(opp);
+	target_volt = dev_pm_opp_get_voltage(opp);
+
+	opp = devfreq_recommended_opp(dev, &dmcfreq.rate, flags);
+	if (IS_ERR(opp)) {
+		rcu_read_unlock();
+		return PTR_ERR(opp);
+	}
+	dmcfreq.volt = dev_pm_opp_get_voltage(opp);
+	rcu_read_unlock();
+
+	if (dmcfreq.rate == dmcfreq.target_rate)
+		return 0;
+
+	mutex_lock(&dmcfreq.lock);
+
+	if (old_clk_rate < target_rate) {
+		err = regulator_set_voltage(dmcfreq.vdd_logic, target_volt,
+					    target_volt);
+		if (err) {
+			dev_err(dev, "Unable to set vol %lu\n", target_volt);
+			goto out;
+		}
+	}
+
+	err = clk_set_rate(dmcfreq.dmc_clk, target_rate);
+	if (err) {
+		dev_err(dev,
+			"Unable to set freq %lu. Current freq %lu. Error %d\n",
+			target_rate, old_clk_rate, err);
+		regulator_set_voltage(dmcfreq.vdd_logic, dmcfreq.volt,
+				      dmcfreq.volt);
+		goto out;
+	}
+
+	dmcfreq.rate = target_rate;
+
+	if (old_clk_rate > target_rate)
+		err = regulator_set_voltage(dmcfreq.vdd_logic, target_volt,
+					    target_volt);
+	if (err)
+		dev_err(dev, "Unable to set vol %lu\n", target_volt);
+out:
+	mutex_unlock(&dmcfreq.lock);
+	return err;
+}
+
+static void rk3399_dmc_start_hardware_counter(void)
+{
+	void __iomem *ctrl_regs = dmcfreq.dmc_data->ctrl_regs;
+	void __iomem *dfi_regs = dmcfreq.dmc_data->dfi_regs;
+	u32 val;
+	u32 ddr_type;
+
+	/* get ddr type */
+	val = readl_relaxed(ctrl_regs + DENALI_CTL_00);
+	ddr_type = (val >> DRAM_CLASS_SHIFT) & DRAM_CLASS_MASK;
+
+	/* set ddr type to dfi */
+	val = readl_relaxed(dfi_regs + DDRMON_CTRL);
+	if (ddr_type == LPDDR3) {
+		val &= ~LPDDR4_EN;
+		val |= LPDDR3_EN;
+	} else if (ddr_type == LPDDR4) {
+		val &= ~LPDDR3_EN;
+		val |= LPDDR4_EN;
+	} else
+		val &= ~(LPDDR3_EN | LPDDR4_EN);
+
+	/* enable count, use software mode */
+	val &= ~HARDWARE_EN;
+	val |= SOFTWARE_EN;
+
+	writel_relaxed(val, dfi_regs + DDRMON_CTRL);
+}
+
+static void rk3399_dmc_stop_hardware_counter(void)
+{
+	void __iomem *dfi_regs = dmcfreq.dmc_data->dfi_regs;
+	u32 val;
+
+	val = readl_relaxed(dfi_regs + DDRMON_CTRL);
+	val &= ~SOFTWARE_EN;
+	writel_relaxed(val, dfi_regs + DDRMON_CTRL);
+}
+
+static int rk3399_dmc_get_busier_ch(void)
+{
+	u32 tmp, max = 0;
+	u32 i, busier_ch = 0;
+	void __iomem *dfi_regs = dmcfreq.dmc_data->dfi_regs;
+
+	rk3399_dmc_stop_hardware_counter();
+
+	/* Find out which channel is busier */
+	for (i = 0; i < RK3399_DMC_NUM_CH; i++) {
+		dmcfreq.ch_usage[i].access = readl_relaxed(dfi_regs +
+				DDRMON_CH0_DFI_ACCESS_NUM + i * 20);
+		dmcfreq.ch_usage[i].total = readl_relaxed(dfi_regs +
+				DDRMON_CH0_COUNT_NUM + i * 20);
+		tmp = dmcfreq.ch_usage[i].access;
+		if (tmp > max) {
+			busier_ch = i;
+			max = tmp;
+		}
+	}
+	rk3399_dmc_start_hardware_counter();
+
+	return busier_ch;
+}
+
+static int rk3399_dmcfreq_get_dev_status(struct device *dev,
+					 struct devfreq_dev_status *stat)
+{
+	int busier_ch;
+
+	busier_ch = rk3399_dmc_get_busier_ch();
+	stat->current_frequency = dmcfreq.rate;
+	stat->busy_time = dmcfreq.ch_usage[busier_ch].access;
+	stat->total_time = dmcfreq.ch_usage[busier_ch].total;
+
+	return 0;
+}
+
+static int rk3399_dmcfreq_get_cur_freq(struct device *dev, unsigned long *freq)
+{
+	*freq = dmcfreq.rate;
+	return 0;
+}
+
+static void rk3399_dmcfreq_exit(struct device *dev)
+{
+	devfreq_unregister_opp_notifier(dmcfreq.clk_dev, dmcfreq.devfreq);
+}
+
+static struct devfreq_dev_profile rk3399_devfreq_dmc_profile = {
+	.polling_ms	= 200,
+	.target		= rk3399_dmcfreq_target,
+	.get_dev_status	= rk3399_dmcfreq_get_dev_status,
+	.get_cur_freq	= rk3399_dmcfreq_get_cur_freq,
+	.exit		= rk3399_dmcfreq_exit,
+};
+
+static __maybe_unused int rk3399_dmcfreq_suspend(struct device *dev)
+{
+	unsigned long freq = ULONG_MAX;
+
+	dev_info(dmcfreq.clk_dev, "suspending DVFS and going to max freq\n");
+	devfreq_suspend_device(dmcfreq.devfreq);
+	rk3399_dmc_stop_hardware_counter();
+	rk3399_dmcfreq_target(dmcfreq.clk_dev, &freq, 0);
+
+	return 0;
+}
+
+static __maybe_unused int rk3399_dmcfreq_resume(struct device *dev)
+{
+	dev_info(dmcfreq.clk_dev, "resuming DVFS\n");
+	rk3399_dmc_start_hardware_counter();
+	devfreq_resume_device(dmcfreq.devfreq);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(rk3399_dmcfreq_pm, rk3399_dmcfreq_suspend,
+			 rk3399_dmcfreq_resume);
+
+static void rk3399_dmcfreq_shutdown(void)
+{
+	devfreq_suspend_device(dmcfreq.devfreq);
+}
+
+static struct syscore_ops rk3399_dmcfreq_syscore_ops = {
+	.shutdown = rk3399_dmcfreq_shutdown,
+};
+
+static int rk3399_dmcfreq_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+
+	dmcfreq.clk_dev = dev->parent;
+	mutex_init(&dmcfreq.lock);
+
+	dmcfreq.dmc_data =
+		(struct rk3399_dmcclk *)dev_get_drvdata(dmcfreq.clk_dev);
+
+	dmcfreq.vdd_logic = regulator_get(dmcfreq.clk_dev, "logic");
+	if (IS_ERR(dmcfreq.vdd_logic)) {
+		dev_err(dev, "Cannot get the regulator \"vdd_logic\"\n");
+		return PTR_ERR(dmcfreq.vdd_logic);
+	}
+
+	dmcfreq.dmc_clk = devm_clk_get(dev, "dmc_clk");
+	if (IS_ERR(dmcfreq.dmc_clk)) {
+		dev_err(dev, "Cannot get the clk dmc_clk\n");
+		return PTR_ERR(dmcfreq.dmc_clk);
+	};
+
+	/*
+	 * We add a devfreq driver to our parent since it has a device tree node
+	 * with operating points.
+	 */
+	if (dev_pm_opp_of_add_table(dmcfreq.clk_dev)) {
+		dev_err(dev, "Invalid operating-points in device tree.\n");
+		return -EINVAL;
+	}
+
+	of_property_read_u32(dmcfreq.clk_dev->of_node, "upthreshold",
+				&dmcfreq.ondemand_data.upthreshold);
+
+	of_property_read_u32(dmcfreq.clk_dev->of_node, "downdifferential",
+				&dmcfreq.ondemand_data.downdifferential);
+
+	dmcfreq.devfreq = devfreq_add_device(dmcfreq.clk_dev,
+					     &rk3399_devfreq_dmc_profile,
+					     "simple_ondemand",
+					     &dmcfreq.ondemand_data);
+	if (IS_ERR(dmcfreq.devfreq))
+		return PTR_ERR(dmcfreq.devfreq);
+
+	devfreq_register_opp_notifier(dmcfreq.clk_dev, dmcfreq.devfreq);
+
+	register_syscore_ops(&rk3399_dmcfreq_syscore_ops);
+
+	return 0;
+}
+
+static int rk3399_dmcfreq_remove(struct platform_device *pdev)
+{
+	devfreq_remove_device(dmcfreq.devfreq);
+	regulator_put(dmcfreq.vdd_logic);
+
+	return 0;
+}
+
+static struct platform_driver rk3399_dmcfreq_driver = {
+	.probe	= rk3399_dmcfreq_probe,
+	.remove	= rk3399_dmcfreq_remove,
+	.driver = {
+		.name	= "rk3399-dmc-freq",
+		.pm	= &rk3399_dmcfreq_pm,
+	},
+};
+module_platform_driver(rk3399_dmcfreq_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("RK3399 dmcfreq driver with devfreq framework");
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/