Merge tag 'tegra-for-4.3-cpufreq' of git://git.kernel.org/pub/scm/lin…

…ux/kernel/git/tegra/linux into next/drivers

ARM: tegra: CPU frequency scaling for v4.3-rc1

This adds CPU frequency scaling support for Tegra124.

* tag 'tegra-for-4.3-cpufreq' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux:
  cpufreq: Add cpufreq driver for Tegra124
  cpufreq: tegra: Rename tegra-cpufreq to tegra20-cpufreq
  cpufreq: tegra124: Add device tree bindings

Signed-off-by: Olof Johansson <olof@lixom.net>

Documentation/devicetree/bindings/cpufreq/tegra124-cpufreq.txt

@@ -0,0 +1,44 @@
+Tegra124 CPU frequency scaling driver bindings
+----------------------------------------------
+
+Both required and optional properties listed below must be defined
+under node /cpus/cpu@0.
+
+Required properties:
+- clocks: Must contain an entry for each entry in clock-names.
+  See ../clocks/clock-bindings.txt for details.
+- clock-names: Must include the following entries:
+  - cpu_g: Clock mux for the fast CPU cluster.
+  - cpu_lp: Clock mux for the low-power CPU cluster.
+  - pll_x: Fast PLL clocksource.
+  - pll_p: Auxiliary PLL used during fast PLL rate changes.
+  - dfll: Fast DFLL clocksource that also automatically scales CPU voltage.
+- vdd-cpu-supply: Regulator for CPU voltage
+
+Optional properties:
+- clock-latency: Specify the possible maximum transition latency for clock,
+  in unit of nanoseconds.
+
+Example:
+--------
+cpus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	cpu@0 {
+		device_type = "cpu";
+		compatible = "arm,cortex-a15";
+		reg = <0>;
+
+		clocks = <&tegra_car TEGRA124_CLK_CCLK_G>,
+			 <&tegra_car TEGRA124_CLK_CCLK_LP>,
+			 <&tegra_car TEGRA124_CLK_PLL_X>,
+			 <&tegra_car TEGRA124_CLK_PLL_P>,
+			 <&dfll>;
+		clock-names = "cpu_g", "cpu_lp", "pll_x", "pll_p", "dfll";
+		clock-latency = <300000>;
+		vdd-cpu-supply: <&vdd_cpu>;
+	};
+
+	<...>
+};

drivers/cpufreq/Kconfig.arm

@@ -247,12 +247,19 @@ config ARM_SPEAR_CPUFREQ
 	help
 	  This adds the CPUFreq driver support for SPEAr SOCs.
 
-config ARM_TEGRA_CPUFREQ
-	bool "TEGRA CPUFreq support"
+config ARM_TEGRA20_CPUFREQ
+	bool "Tegra20 CPUFreq support"
 	depends on ARCH_TEGRA
 	default y
 	help
-	  This adds the CPUFreq driver support for TEGRA SOCs.
+	  This adds the CPUFreq driver support for Tegra20 SOCs.
+
+config ARM_TEGRA124_CPUFREQ
+	tristate "Tegra124 CPUFreq support"
+	depends on ARCH_TEGRA && CPUFREQ_DT
+	default y
+	help
+	  This adds the CPUFreq driver support for Tegra124 SOCs.
 
 config ARM_PXA2xx_CPUFREQ
 	tristate "Intel PXA2xx CPUfreq driver"

drivers/cpufreq/Makefile

@@ -76,7 +76,8 @@ obj-$(CONFIG_ARM_S5PV210_CPUFREQ)	+= s5pv210-cpufreq.o
 obj-$(CONFIG_ARM_SA1100_CPUFREQ)	+= sa1100-cpufreq.o
 obj-$(CONFIG_ARM_SA1110_CPUFREQ)	+= sa1110-cpufreq.o
 obj-$(CONFIG_ARM_SPEAR_CPUFREQ)		+= spear-cpufreq.o
-obj-$(CONFIG_ARM_TEGRA_CPUFREQ)		+= tegra-cpufreq.o
+obj-$(CONFIG_ARM_TEGRA20_CPUFREQ)	+= tegra20-cpufreq.o
+obj-$(CONFIG_ARM_TEGRA124_CPUFREQ)	+= tegra124-cpufreq.o
 obj-$(CONFIG_ARM_VEXPRESS_SPC_CPUFREQ)	+= vexpress-spc-cpufreq.o
 
 ##################################################################################

drivers/cpufreq/tegra124-cpufreq.c

@@ -0,0 +1,214 @@
+/*
+ * Tegra 124 cpufreq driver
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that 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.
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+
+#include <linux/clk.h>
+#include <linux/cpufreq-dt.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/regulator/consumer.h>
+#include <linux/types.h>
+
+struct tegra124_cpufreq_priv {
+	struct regulator *vdd_cpu_reg;
+	struct clk *cpu_clk;
+	struct clk *pllp_clk;
+	struct clk *pllx_clk;
+	struct clk *dfll_clk;
+	struct platform_device *cpufreq_dt_pdev;
+};
+
+static int tegra124_cpu_switch_to_dfll(struct tegra124_cpufreq_priv *priv)
+{
+	struct clk *orig_parent;
+	int ret;
+
+	ret = clk_set_rate(priv->dfll_clk, clk_get_rate(priv->cpu_clk));
+	if (ret)
+		return ret;
+
+	orig_parent = clk_get_parent(priv->cpu_clk);
+	clk_set_parent(priv->cpu_clk, priv->pllp_clk);
+
+	ret = clk_prepare_enable(priv->dfll_clk);
+	if (ret)
+		goto out;
+
+	clk_set_parent(priv->cpu_clk, priv->dfll_clk);
+
+	return 0;
+
+out:
+	clk_set_parent(priv->cpu_clk, orig_parent);
+
+	return ret;
+}
+
+static void tegra124_cpu_switch_to_pllx(struct tegra124_cpufreq_priv *priv)
+{
+	clk_set_parent(priv->cpu_clk, priv->pllp_clk);
+	clk_disable_unprepare(priv->dfll_clk);
+	regulator_sync_voltage(priv->vdd_cpu_reg);
+	clk_set_parent(priv->cpu_clk, priv->pllx_clk);
+}
+
+static struct cpufreq_dt_platform_data cpufreq_dt_pd = {
+	.independent_clocks = false,
+};
+
+static int tegra124_cpufreq_probe(struct platform_device *pdev)
+{
+	struct tegra124_cpufreq_priv *priv;
+	struct device_node *np;
+	struct device *cpu_dev;
+	struct platform_device_info cpufreq_dt_devinfo = {};
+	int ret;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	cpu_dev = get_cpu_device(0);
+	if (!cpu_dev)
+		return -ENODEV;
+
+	np = of_cpu_device_node_get(0);
+	if (!np)
+		return -ENODEV;
+
+	priv->vdd_cpu_reg = regulator_get(cpu_dev, "vdd-cpu");
+	if (IS_ERR(priv->vdd_cpu_reg)) {
+		ret = PTR_ERR(priv->vdd_cpu_reg);
+		goto out_put_np;
+	}
+
+	priv->cpu_clk = of_clk_get_by_name(np, "cpu_g");
+	if (IS_ERR(priv->cpu_clk)) {
+		ret = PTR_ERR(priv->cpu_clk);
+		goto out_put_vdd_cpu_reg;
+	}
+
+	priv->dfll_clk = of_clk_get_by_name(np, "dfll");
+	if (IS_ERR(priv->dfll_clk)) {
+		ret = PTR_ERR(priv->dfll_clk);
+		goto out_put_cpu_clk;
+	}
+
+	priv->pllx_clk = of_clk_get_by_name(np, "pll_x");
+	if (IS_ERR(priv->pllx_clk)) {
+		ret = PTR_ERR(priv->pllx_clk);
+		goto out_put_dfll_clk;
+	}
+
+	priv->pllp_clk = of_clk_get_by_name(np, "pll_p");
+	if (IS_ERR(priv->pllp_clk)) {
+		ret = PTR_ERR(priv->pllp_clk);
+		goto out_put_pllx_clk;
+	}
+
+	ret = tegra124_cpu_switch_to_dfll(priv);
+	if (ret)
+		goto out_put_pllp_clk;
+
+	cpufreq_dt_devinfo.name = "cpufreq-dt";
+	cpufreq_dt_devinfo.parent = &pdev->dev;
+	cpufreq_dt_devinfo.data = &cpufreq_dt_pd;
+	cpufreq_dt_devinfo.size_data = sizeof(cpufreq_dt_pd);
+
+	priv->cpufreq_dt_pdev =
+		platform_device_register_full(&cpufreq_dt_devinfo);
+	if (IS_ERR(priv->cpufreq_dt_pdev)) {
+		ret = PTR_ERR(priv->cpufreq_dt_pdev);
+		goto out_switch_to_pllx;
+	}
+
+	platform_set_drvdata(pdev, priv);
+
+	return 0;
+
+out_switch_to_pllx:
+	tegra124_cpu_switch_to_pllx(priv);
+out_put_pllp_clk:
+	clk_put(priv->pllp_clk);
+out_put_pllx_clk:
+	clk_put(priv->pllx_clk);
+out_put_dfll_clk:
+	clk_put(priv->dfll_clk);
+out_put_cpu_clk:
+	clk_put(priv->cpu_clk);
+out_put_vdd_cpu_reg:
+	regulator_put(priv->vdd_cpu_reg);
+out_put_np:
+	of_node_put(np);
+
+	return ret;
+}
+
+static int tegra124_cpufreq_remove(struct platform_device *pdev)
+{
+	struct tegra124_cpufreq_priv *priv = platform_get_drvdata(pdev);
+
+	platform_device_unregister(priv->cpufreq_dt_pdev);
+	tegra124_cpu_switch_to_pllx(priv);
+
+	clk_put(priv->pllp_clk);
+	clk_put(priv->pllx_clk);
+	clk_put(priv->dfll_clk);
+	clk_put(priv->cpu_clk);
+	regulator_put(priv->vdd_cpu_reg);
+
+	return 0;
+}
+
+static struct platform_driver tegra124_cpufreq_platdrv = {
+	.driver.name	= "cpufreq-tegra124",
+	.probe		= tegra124_cpufreq_probe,
+	.remove		= tegra124_cpufreq_remove,
+};
+
+static int __init tegra_cpufreq_init(void)
+{
+	int ret;
+	struct platform_device *pdev;
+
+	if (!of_machine_is_compatible("nvidia,tegra124"))
+		return -ENODEV;
+
+	/*
+	 * Platform driver+device required for handling EPROBE_DEFER with
+	 * the regulator and the DFLL clock
+	 */
+	ret = platform_driver_register(&tegra124_cpufreq_platdrv);
+	if (ret)
+		return ret;
+
+	pdev = platform_device_register_simple("cpufreq-tegra124", -1, NULL, 0);
+	if (IS_ERR(pdev)) {
+		platform_driver_unregister(&tegra124_cpufreq_platdrv);
+		return PTR_ERR(pdev);
+	}
+
+	return 0;
+}
+module_init(tegra_cpufreq_init);
+
+MODULE_AUTHOR("Tuomas Tynkkynen <ttynkkynen@nvidia.com>");
+MODULE_DESCRIPTION("cpufreq driver for NVIDIA Tegra124");
+MODULE_LICENSE("GPL v2");