Merge tag 'tegra-for-4.3-clk' of...

Merge tag 'tegra-for-4.3-clk' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into clk-next

clk: tegra: Changes for v4.3-rc1

This contains the DFLL driver needed to implement CPU frequency scaling
on Tegra.

Documentation/devicetree/bindings/clock/nvidia,tegra124-dfll.txt

+NVIDIA Tegra124 DFLL FCPU clocksource
+
+This binding uses the common clock binding:
+Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+The DFLL IP block on Tegra is a root clocksource designed for clocking
+the fast CPU cluster. It consists of a free-running voltage controlled
+oscillator connected to the CPU voltage rail (VDD_CPU), and a closed loop
+control module that will automatically adjust the VDD_CPU voltage by
+communicating with an off-chip PMIC either via an I2C bus or via PWM signals.
+Currently only the I2C mode is supported by these bindings.
+
+Required properties:
+- compatible : should be "nvidia,tegra124-dfll"
+- reg : Defines the following set of registers, in the order listed:
+        - registers for the DFLL control logic.
+        - registers for the I2C output logic.
+        - registers for the integrated I2C master controller.
+        - look-up table RAM for voltage register values.
+- interrupts: Should contain the DFLL block interrupt.
+- clocks: Must contain an entry for each entry in clock-names.
+  See clock-bindings.txt for details.
+- clock-names: Must include the following entries:
+  - soc: Clock source for the DFLL control logic.
+  - ref: The closed loop reference clock
+  - i2c: Clock source for the integrated I2C master.
+- resets: Must contain an entry for each entry in reset-names.
+  See ../reset/reset.txt for details.
+- reset-names: Must include the following entries:
+  - dvco: Reset control for the DFLL DVCO.
+- #clock-cells: Must be 0.
+- clock-output-names: Name of the clock output.
+- vdd-cpu-supply: Regulator for the CPU voltage rail that the DFLL
+  hardware will start controlling. The regulator will be queried for
+  the I2C register, control values and supported voltages.
+
+Required properties for the control loop parameters:
+- nvidia,sample-rate: Sample rate of the DFLL control loop.
+- nvidia,droop-ctrl: See the register CL_DVFS_DROOP_CTRL in the TRM.
+- nvidia,force-mode: See the field DFLL_PARAMS_FORCE_MODE in the TRM.
+- nvidia,cf: Numeric value, see the field DFLL_PARAMS_CF_PARAM in the TRM.
+- nvidia,ci: Numeric value, see the field DFLL_PARAMS_CI_PARAM in the TRM.
+- nvidia,cg: Numeric value, see the field DFLL_PARAMS_CG_PARAM in the TRM.
+
+Optional properties for the control loop parameters:
+- nvidia,cg-scale: Boolean value, see the field DFLL_PARAMS_CG_SCALE in the TRM.
+
+Required properties for I2C mode:
+- nvidia,i2c-fs-rate: I2C transfer rate, if using full speed mode.
+
+Example:
+
+clock@0,70110000 {
+        compatible = "nvidia,tegra124-dfll";
+        reg = <0 0x70110000 0 0x100>, /* DFLL control */
+              <0 0x70110000 0 0x100>, /* I2C output control */
+              <0 0x70110100 0 0x100>, /* Integrated I2C controller */
+              <0 0x70110200 0 0x100>; /* Look-up table RAM */
+        interrupts = <GIC_SPI 62 IRQ_TYPE_LEVEL_HIGH>;
+        clocks = <&tegra_car TEGRA124_CLK_DFLL_SOC>,
+                 <&tegra_car TEGRA124_CLK_DFLL_REF>,
+                 <&tegra_car TEGRA124_CLK_I2C5>;
+        clock-names = "soc", "ref", "i2c";
+        resets = <&tegra_car TEGRA124_RST_DFLL_DVCO>;
+        reset-names = "dvco";
+        #clock-cells = <0>;
+        clock-output-names = "dfllCPU_out";
+        vdd-cpu-supply = <&vdd_cpu>;
+        status = "okay";
+
+        nvidia,sample-rate = <12500>;
+        nvidia,droop-ctrl = <0x00000f00>;
+        nvidia,force-mode = <1>;
+        nvidia,cf = <10>;
+        nvidia,ci = <0>;
+        nvidia,cg = <2>;
+
+        nvidia,i2c-fs-rate = <400000>;
+};

arch/arm/mach-tegra/Kconfig

@@ -8,6 +8,7 @@ menuconfig ARCH_TEGRA
 	select HAVE_ARM_SCU if SMP
 	select HAVE_ARM_TWD if SMP
 	select PINCTRL
+	select PM_OPP
 	select ARCH_HAS_RESET_CONTROLLER
 	select RESET_CONTROLLER
 	select SOC_BUS

drivers/clk/tegra/Makefile

 obj-y					+= clk.o
 obj-y					+= clk-audio-sync.o
+obj-y					+= clk-dfll.o
 obj-y					+= clk-divider.o
 obj-y					+= clk-periph.o
 obj-y					+= clk-periph-gate.o
@@ -16,4 +17,6 @@ obj-$(CONFIG_ARCH_TEGRA_2x_SOC)         += clk-tegra20.o
 obj-$(CONFIG_ARCH_TEGRA_3x_SOC)         += clk-tegra30.o
 obj-$(CONFIG_ARCH_TEGRA_114_SOC)	+= clk-tegra114.o
 obj-$(CONFIG_ARCH_TEGRA_124_SOC)	+= clk-tegra124.o
+obj-$(CONFIG_ARCH_TEGRA_124_SOC)	+= clk-tegra124-dfll-fcpu.o
 obj-$(CONFIG_ARCH_TEGRA_132_SOC)	+= clk-tegra124.o
+obj-y					+= cvb.o

drivers/clk/tegra/clk-dfll.h

+/*
+ * clk-dfll.h - prototypes and macros for the Tegra DFLL clocksource driver
+ * Copyright (C) 2013 NVIDIA Corporation.  All rights reserved.
+ *
+ * Aleksandr Frid <afrid@nvidia.com>
+ * Paul Walmsley <pwalmsley@nvidia.com>
+ *
+ * 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.
+ *
+ * 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.
+ */
+
+#ifndef __DRIVERS_CLK_TEGRA_CLK_DFLL_H
+#define __DRIVERS_CLK_TEGRA_CLK_DFLL_H
+
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/types.h>
+
+/**
+ * struct tegra_dfll_soc_data - SoC-specific hooks/integration for the DFLL driver
+ * @opp_dev: struct device * that holds the OPP table for the DFLL
+ * @min_millivolts: minimum voltage (in mV) that the DFLL can operate
+ * @tune0_low: DFLL tuning register 0 (low voltage range)
+ * @tune0_high: DFLL tuning register 0 (high voltage range)
+ * @tune1: DFLL tuning register 1
+ * @assert_dvco_reset: fn ptr to place the DVCO in reset
+ * @deassert_dvco_reset: fn ptr to release the DVCO reset
+ * @set_clock_trimmers_high: fn ptr to tune clock trimmers for high voltage
+ * @set_clock_trimmers_low: fn ptr to tune clock trimmers for low voltage
+ */
+struct tegra_dfll_soc_data {
+	struct device *dev;
+	unsigned int min_millivolts;
+	u32 tune0_low;
+	u32 tune0_high;
+	u32 tune1;
+	void (*init_clock_trimmers)(void);
+	void (*set_clock_trimmers_high)(void);
+	void (*set_clock_trimmers_low)(void);
+};
+
+int tegra_dfll_register(struct platform_device *pdev,
+			struct tegra_dfll_soc_data *soc);
+int tegra_dfll_unregister(struct platform_device *pdev);
+int tegra_dfll_runtime_suspend(struct device *dev);
+int tegra_dfll_runtime_resume(struct device *dev);
+
+#endif /* __DRIVERS_CLK_TEGRA_CLK_DFLL_H */

drivers/clk/tegra/clk-tegra-super-gen4.c

@@ -43,7 +43,9 @@ static const char *sclk_parents[] = { "clk_m", "pll_c_out1", "pll_p_out4",
 
 static const char *cclk_g_parents[] = { "clk_m", "pll_c", "clk_32k", "pll_m",
 					"pll_p", "pll_p_out4", "unused",
-					"unused", "pll_x" };
+					"unused", "pll_x", "unused", "unused",
+					"unused", "unused", "unused", "unused",
+					"dfllCPU_out" };
 
 static const char *cclk_lp_parents[] = { "clk_m", "pll_c", "clk_32k", "pll_m",
 					 "pll_p", "pll_p_out4", "unused",

drivers/clk/tegra/clk-tegra124-dfll-fcpu.c

+/*
+ * Tegra124 DFLL FCPU clock source driver
+ *
+ * Copyright (C) 2012-2014 NVIDIA Corporation.  All rights reserved.
+ *
+ * Aleksandr Frid <afrid@nvidia.com>
+ * Paul Walmsley <pwalmsley@nvidia.com>
+ *
+ * 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.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/cpu.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <soc/tegra/fuse.h>
+
+#include "clk.h"
+#include "clk-dfll.h"
+#include "cvb.h"
+
+/* Maximum CPU frequency, indexed by CPU speedo id */
+static const unsigned long cpu_max_freq_table[] = {
+	[0] = 2014500000UL,
+	[1] = 2320500000UL,
+	[2] = 2116500000UL,
+	[3] = 2524500000UL,
+};
+
+static const struct cvb_table tegra124_cpu_cvb_tables[] = {
+	{
+		.speedo_id = -1,
+		.process_id = -1,
+		.min_millivolts = 900,
+		.max_millivolts = 1260,
+		.alignment = {
+			.step_uv = 10000, /* 10mV */
+		},
+		.speedo_scale = 100,
+		.voltage_scale = 1000,
+		.cvb_table = {
+			{204000000UL,   {1112619, -29295, 402} },
+			{306000000UL,	{1150460, -30585, 402} },
+			{408000000UL,	{1190122, -31865, 402} },
+			{510000000UL,	{1231606, -33155, 402} },
+			{612000000UL,	{1274912, -34435, 402} },
+			{714000000UL,	{1320040, -35725, 402} },
+			{816000000UL,	{1366990, -37005, 402} },
+			{918000000UL,	{1415762, -38295, 402} },
+			{1020000000UL,	{1466355, -39575, 402} },
+			{1122000000UL,	{1518771, -40865, 402} },
+			{1224000000UL,	{1573009, -42145, 402} },
+			{1326000000UL,	{1629068, -43435, 402} },
+			{1428000000UL,	{1686950, -44715, 402} },
+			{1530000000UL,	{1746653, -46005, 402} },
+			{1632000000UL,	{1808179, -47285, 402} },
+			{1734000000UL,	{1871526, -48575, 402} },
+			{1836000000UL,	{1936696, -49855, 402} },
+			{1938000000UL,	{2003687, -51145, 402} },
+			{2014500000UL,	{2054787, -52095, 402} },
+			{2116500000UL,	{2124957, -53385, 402} },
+			{2218500000UL,	{2196950, -54665, 402} },
+			{2320500000UL,	{2270765, -55955, 402} },
+			{2422500000UL,	{2346401, -57235, 402} },
+			{2524500000UL,	{2437299, -58535, 402} },
+			{0,		{      0,      0,   0} },
+		},
+		.cpu_dfll_data = {
+			.tune0_low = 0x005020ff,
+			.tune0_high = 0x005040ff,
+			.tune1 = 0x00000060,
+		}
+	},
+};
+
+static int tegra124_dfll_fcpu_probe(struct platform_device *pdev)
+{
+	int process_id, speedo_id, speedo_value;
+	struct tegra_dfll_soc_data *soc;
+	const struct cvb_table *cvb;
+
+	process_id = tegra_sku_info.cpu_process_id;
+	speedo_id = tegra_sku_info.cpu_speedo_id;
+	speedo_value = tegra_sku_info.cpu_speedo_value;
+
+	if (speedo_id >= ARRAY_SIZE(cpu_max_freq_table)) {
+		dev_err(&pdev->dev, "unknown max CPU freq for speedo_id=%d\n",
+			speedo_id);
+		return -ENODEV;
+	}
+
+	soc = devm_kzalloc(&pdev->dev, sizeof(*soc), GFP_KERNEL);
+	if (!soc)
+		return -ENOMEM;
+
+	soc->dev = get_cpu_device(0);
+	if (!soc->dev) {
+		dev_err(&pdev->dev, "no CPU0 device\n");
+		return -ENODEV;
+	}
+
+	cvb = tegra_cvb_build_opp_table(tegra124_cpu_cvb_tables,
+					ARRAY_SIZE(tegra124_cpu_cvb_tables),
+					process_id, speedo_id, speedo_value,
+					cpu_max_freq_table[speedo_id],
+					soc->dev);
+	if (IS_ERR(cvb)) {
+		dev_err(&pdev->dev, "couldn't build OPP table: %ld\n",
+			PTR_ERR(cvb));
+		return PTR_ERR(cvb);
+	}
+
+	soc->min_millivolts = cvb->min_millivolts;
+	soc->tune0_low = cvb->cpu_dfll_data.tune0_low;
+	soc->tune0_high = cvb->cpu_dfll_data.tune0_high;
+	soc->tune1 = cvb->cpu_dfll_data.tune1;
+
+	return tegra_dfll_register(pdev, soc);
+}
+
+static const struct of_device_id tegra124_dfll_fcpu_of_match[] = {
+	{ .compatible = "nvidia,tegra124-dfll", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, tegra124_dfll_fcpu_of_match);
+
+static const struct dev_pm_ops tegra124_dfll_pm_ops = {
+	SET_RUNTIME_PM_OPS(tegra_dfll_runtime_suspend,
+			   tegra_dfll_runtime_resume, NULL)
+};
+
+static struct platform_driver tegra124_dfll_fcpu_driver = {
+	.probe = tegra124_dfll_fcpu_probe,
+	.remove = tegra_dfll_unregister,
+	.driver = {
+		.name = "tegra124-dfll",
+		.of_match_table = tegra124_dfll_fcpu_of_match,
+		.pm = &tegra124_dfll_pm_ops,
+	},
+};
+
+static int __init tegra124_dfll_fcpu_init(void)
+{
+	return platform_driver_register(&tegra124_dfll_fcpu_driver);
+}
+module_init(tegra124_dfll_fcpu_init);
+
+static void __exit tegra124_dfll_fcpu_exit(void)
+{
+	platform_driver_unregister(&tegra124_dfll_fcpu_driver);
+}
+module_exit(tegra124_dfll_fcpu_exit);
+
+MODULE_DESCRIPTION("Tegra124 DFLL clock source driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Aleksandr Frid <afrid@nvidia.com>");
+MODULE_AUTHOR("Paul Walmsley <pwalmsley@nvidia.com>");

drivers/clk/tegra/clk-tegra124.c

@@ -23,6 +23,7 @@
 #include <linux/export.h>
 #include <linux/clk/tegra.h>
 #include <dt-bindings/clock/tegra124-car.h>
+#include <dt-bindings/reset/tegra124-car.h>
 
 #include "clk.h"
 #include "clk-id.h"
@@ -38,6 +39,9 @@
 #define CLK_SOURCE_CSITE 0x1d4
 #define CLK_SOURCE_EMC 0x19c
 
+#define RST_DFLL_DVCO			0x2f4
+#define DVFS_DFLL_RESET_SHIFT		0
+
 #define PLLC_BASE 0x80
 #define PLLC_OUT 0x84
 #define PLLC_MISC2 0x88
@@ -93,6 +97,8 @@
 #define PMC_PLLM_WB0_OVERRIDE 0x1dc
 #define PMC_PLLM_WB0_OVERRIDE_2 0x2b0
 
+#define CCLKG_BURST_POLICY 0x368
+
 #define UTMIP_PLL_CFG2 0x488
 #define UTMIP_PLL_CFG2_STABLE_COUNT(x) (((x) & 0xffff) << 6)
 #define UTMIP_PLL_CFG2_ACTIVE_DLY_COUNT(x) (((x) & 0x3f) << 18)
@@ -125,6 +131,8 @@
 #ifdef CONFIG_PM_SLEEP
 static struct cpu_clk_suspend_context {
 	u32 clk_csite_src;
+	u32 cclkg_burst;
+	u32 cclkg_divider;
 } tegra124_cpu_clk_sctx;
 #endif
 
@@ -1318,12 +1326,22 @@ static void tegra124_cpu_clock_suspend(void)
 	tegra124_cpu_clk_sctx.clk_csite_src =
 				readl(clk_base + CLK_SOURCE_CSITE);
 	writel(3 << 30, clk_base + CLK_SOURCE_CSITE);
+
+	tegra124_cpu_clk_sctx.cclkg_burst =
+				readl(clk_base + CCLKG_BURST_POLICY);
+	tegra124_cpu_clk_sctx.cclkg_divider =
+				readl(clk_base + CCLKG_BURST_POLICY + 4);
 }
 
 static void tegra124_cpu_clock_resume(void)
 {
 	writel(tegra124_cpu_clk_sctx.clk_csite_src,
 				clk_base + CLK_SOURCE_CSITE);
+
+	writel(tegra124_cpu_clk_sctx.cclkg_burst,
+					clk_base + CCLKG_BURST_POLICY);
+	writel(tegra124_cpu_clk_sctx.cclkg_divider,
+					clk_base + CCLKG_BURST_POLICY + 4);
 }
 #endif
 
@@ -1413,6 +1431,68 @@ static void __init tegra124_clock_apply_init_table(void)
 	tegra_init_from_table(tegra124_init_table, clks, TEGRA124_CLK_CLK_MAX);
 }
 
+/**
+ * tegra124_car_barrier - wait for pending writes to the CAR to complete
+ *
+ * Wait for any outstanding writes to the CAR MMIO space from this CPU
+ * to complete before continuing execution.  No return value.
+ */
+static void tegra124_car_barrier(void)
+{
+	readl_relaxed(clk_base + RST_DFLL_DVCO);
+}
+
+/**
+ * tegra124_clock_assert_dfll_dvco_reset - assert the DFLL's DVCO reset
+ *
+ * Assert the reset line of the DFLL's DVCO.  No return value.
+ */
+void tegra124_clock_assert_dfll_dvco_reset(void)
+{
+	u32 v;
+
+	v = readl_relaxed(clk_base + RST_DFLL_DVCO);
+	v |= (1 << DVFS_DFLL_RESET_SHIFT);
+	writel_relaxed(v, clk_base + RST_DFLL_DVCO);
+	tegra124_car_barrier();
+}
+
+/**
+ * tegra124_clock_deassert_dfll_dvco_reset - deassert the DFLL's DVCO reset
+ *
+ * Deassert the reset line of the DFLL's DVCO, allowing the DVCO to
+ * operate.  No return value.
+ */
+void tegra124_clock_deassert_dfll_dvco_reset(void)
+{
+	u32 v;
+
+	v = readl_relaxed(clk_base + RST_DFLL_DVCO);
+	v &= ~(1 << DVFS_DFLL_RESET_SHIFT);
+	writel_relaxed(v, clk_base + RST_DFLL_DVCO);
+	tegra124_car_barrier();
+}
+
+int tegra124_reset_assert(unsigned long id)
+{
+	if (id == TEGRA124_RST_DFLL_DVCO)
+		tegra124_clock_assert_dfll_dvco_reset();
+	else
+		return -EINVAL;
+
+	return 0;
+}
+
+int tegra124_reset_deassert(unsigned long id)
+{
+	if (id == TEGRA124_RST_DFLL_DVCO)
+		tegra124_clock_deassert_dfll_dvco_reset();
+	else
+		return -EINVAL;
+
+	return 0;
+}
+
 /**
  * tegra132_clock_apply_init_table - initialize clocks on Tegra132 SoCs
  *
@@ -1498,6 +1578,8 @@ static void __init tegra124_132_clock_init_post(struct device_node *np)
 {
 	tegra_super_clk_gen4_init(clk_base, pmc_base, tegra124_clks,
 				  &pll_x_params);
+	tegra_init_special_resets(1, tegra124_reset_assert,
+				  tegra124_reset_deassert);
 	tegra_add_of_provider(np);
 
 	clks[TEGRA124_CLK_EMC] = tegra_clk_register_emc(clk_base, np,

drivers/clk/tegra/clk.c

@@ -50,7 +50,6 @@
 #define RST_DEVICES_L			0x004
 #define RST_DEVICES_H			0x008
 #define RST_DEVICES_U			0x00C
-#define RST_DFLL_DVCO			0x2F4
 #define RST_DEVICES_V			0x358
 #define RST_DEVICES_W			0x35C
 #define RST_DEVICES_X			0x28C
@@ -80,6 +79,11 @@ static struct clk **clks;
 static int clk_num;
 static struct clk_onecell_data clk_data;
 
+/* Handlers for SoC-specific reset lines */
+static int (*special_reset_assert)(unsigned long);
+static int (*special_reset_deassert)(unsigned long);
+static unsigned int num_special_reset;
+
 static struct tegra_clk_periph_regs periph_regs[] = {
 	[0] = {
 		.enb_reg = CLK_OUT_ENB_L,
@@ -153,19 +157,29 @@ static int tegra_clk_rst_assert(struct reset_controller_dev *rcdev,
 	 */
 	tegra_read_chipid();
 
+	if (id < periph_banks * 32) {
 		writel_relaxed(BIT(id % 32),
 			       clk_base + periph_regs[id / 32].rst_set_reg);
-
 		return 0;
+	} else if (id < periph_banks * 32 + num_special_reset) {
+		return special_reset_assert(id);
+	}
+
+	return -EINVAL;
 }
 
 static int tegra_clk_rst_deassert(struct reset_controller_dev *rcdev,
 		unsigned long id)
 {
+	if (id < periph_banks * 32) {
 		writel_relaxed(BIT(id % 32),
 			       clk_base + periph_regs[id / 32].rst_clr_reg);
-
 		return 0;
+	} else if (id < periph_banks * 32 + num_special_reset) {
+		return special_reset_deassert(id);
+	}
+
+	return -EINVAL;
 }
 
 struct tegra_clk_periph_regs *get_reg_bank(int clkid)
@@ -287,10 +301,19 @@ void __init tegra_add_of_provider(struct device_node *np)
 	of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
 
 	rst_ctlr.of_node = np;
-	rst_ctlr.nr_resets = periph_banks * 32;
+	rst_ctlr.nr_resets = periph_banks * 32 + num_special_reset;
 	reset_controller_register(&rst_ctlr);
 }
 
+void __init tegra_init_special_resets(unsigned int num,
+				      int (*assert)(unsigned long),
+				      int (*deassert)(unsigned long))
+{
+	num_special_reset = num;
+	special_reset_assert = assert;
+	special_reset_deassert = deassert;
+}
+
 void __init tegra_register_devclks(struct tegra_devclk *dev_clks, int num)
 {
 	int i;

drivers/clk/tegra/clk.h

@@ -591,6 +591,9 @@ struct tegra_devclk {
 	char		*con_id;
 };
 
+void tegra_init_special_resets(unsigned int num, int (*assert)(unsigned long),
+			       int (*deassert)(unsigned long));
+
 void tegra_init_from_table(struct tegra_clk_init_table *tbl,
 		struct clk *clks[], int clk_max);
 

drivers/clk/tegra/cvb.c

+/*
+ * Utility functions for parsing Tegra CVB voltage tables
+ *
+ * Copyright (C) 2012-2014 NVIDIA Corporation.  All rights reserved.
+ *
+ * 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.
+ *
+ * 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.
+ *
+ */
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/pm_opp.h>
+
+#include "cvb.h"
+
+/* cvb_mv = ((c2 * speedo / s_scale + c1) * speedo / s_scale + c0) */
+static inline int get_cvb_voltage(int speedo, int s_scale,
+				  const struct cvb_coefficients *cvb)
+{
+	int mv;
+
+	/* apply only speedo scale: output mv = cvb_mv * v_scale */
+	mv = DIV_ROUND_CLOSEST(cvb->c2 * speedo, s_scale);
+	mv = DIV_ROUND_CLOSEST((mv + cvb->c1) * speedo, s_scale) + cvb->c0;
+	return mv;
+}
+
+static int round_cvb_voltage(int mv, int v_scale,
+			     const struct rail_alignment *align)
+{
+	/* combined: apply voltage scale and round to cvb alignment step */
+	int uv;
+	int step = (align->step_uv ? : 1000) * v_scale;
+	int offset = align->offset_uv * v_scale;
+
+	uv = max(mv * 1000, offset) - offset;
+	uv = DIV_ROUND_UP(uv, step) * align->step_uv + align->offset_uv;
+	return uv / 1000;
+}
+
+enum {
+	DOWN,
+	UP
+};
+
+static int round_voltage(int mv, const struct rail_alignment *align, int up)
+{
+	if (align->step_uv) {
+		int uv;
+
+		uv = max(mv * 1000, align->offset_uv) - align->offset_uv;
+		uv = (uv + (up ? align->step_uv - 1 : 0)) / align->step_uv;
+		return (uv * align->step_uv + align->offset_uv) / 1000;
+	}
+	return mv;
+}
+
+static int build_opp_table(const struct cvb_table *d,
+			   int speedo_value,
+			   unsigned long max_freq,
+			   struct device *opp_dev)
+{
+	int i, ret, dfll_mv, min_mv, max_mv;
+	const struct cvb_table_freq_entry *table = NULL;
+	const struct rail_alignment *align = &d->alignment;
+
+	min_mv = round_voltage(d->min_millivolts, align, UP);
+	max_mv = round_voltage(d->max_millivolts, align, DOWN);
+
+	for (i = 0; i < MAX_DVFS_FREQS; i++) {
+		table = &d->cvb_table[i];
+		if (!table->freq || (table->freq > max_freq))
+			break;
+
+		/*
+		 * FIXME after clk_round_rate/clk_determine_rate prototypes
+		 * have been updated
+		 */
+		if (table->freq & (1<<31))
+			continue;
+
+		dfll_mv = get_cvb_voltage(
+			speedo_value, d->speedo_scale, &table->coefficients);
+		dfll_mv = round_cvb_voltage(dfll_mv, d->voltage_scale, align);
+		dfll_mv = clamp(dfll_mv, min_mv, max_mv);
+
+		ret = dev_pm_opp_add(opp_dev, table->freq, dfll_mv * 1000);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * tegra_cvb_build_opp_table - build OPP table from Tegra CVB tables
+ * @cvb_tables: array of CVB tables
+ * @sz: size of the previously mentioned array
+ * @process_id: process id of the HW module
+ * @speedo_id: speedo id of the HW module
+ * @speedo_value: speedo value of the HW module
+ * @max_rate: highest safe clock rate
+ * @opp_dev: the struct device * for which the OPP table is built
+ *
+ * On Tegra, a CVB table encodes the relationship between operating voltage
+ * and safe maximal frequency for a given module (e.g. GPU or CPU). This
+ * function calculates the optimal voltage-frequency operating points
+ * for the given arguments and exports them via the OPP library for the
+ * given @opp_dev. Returns a pointer to the struct cvb_table that matched
+ * or an ERR_PTR on failure.
+ */
+const struct cvb_table *tegra_cvb_build_opp_table(
+		const struct cvb_table *cvb_tables,
+		size_t sz, int process_id,
+		int speedo_id, int speedo_value,
+		unsigned long max_rate,
+		struct device *opp_dev)
+{
+	int i, ret;
+
+	for (i = 0; i < sz; i++) {
+		const struct cvb_table *d = &cvb_tables[i];
+
+		if (d->speedo_id != -1 && d->speedo_id != speedo_id)
+			continue;
+		if (d->process_id != -1 && d->process_id != process_id)
+			continue;
+
+		ret = build_opp_table(d, speedo_value, max_rate, opp_dev);
+		return ret ? ERR_PTR(ret) : d;
+	}
+
+	return ERR_PTR(-EINVAL);
+}

drivers/clk/tegra/cvb.h

+/*
+ * Utility functions for parsing Tegra CVB voltage tables
+ *
+ * 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.
+ *
+ * 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.
+ *
+ */
+
+#ifndef __DRIVERS_CLK_TEGRA_CVB_H
+#define __DRIVERS_CLK_TEGRA_CVB_H
+
+#include <linux/types.h>
+
+struct device;
+
+#define MAX_DVFS_FREQS	40
+
+struct rail_alignment {
+	int offset_uv;
+	int step_uv;
+};
+
+struct cvb_coefficients {
+	int c0;
+	int c1;
+	int c2;
+};
+
+struct cvb_table_freq_entry {
+	unsigned long freq;
+	struct cvb_coefficients coefficients;
+};
+
+struct cvb_cpu_dfll_data {
+	u32 tune0_low;
+	u32 tune0_high;
+	u32 tune1;
+};
+
+struct cvb_table {
+	int speedo_id;
+	int process_id;
+
+	int min_millivolts;
+	int max_millivolts;
+	struct rail_alignment alignment;
+
+	int speedo_scale;
+	int voltage_scale;
+	struct cvb_table_freq_entry cvb_table[MAX_DVFS_FREQS];
+	struct cvb_cpu_dfll_data cpu_dfll_data;
+};
+
+const struct cvb_table *tegra_cvb_build_opp_table(
+		const struct cvb_table *cvb_tables,
+		size_t sz, int process_id,
+		int speedo_id, int speedo_value,
+		unsigned long max_rate,
+		struct device *opp_dev);
+
+#endif

include/dt-bindings/reset/tegra124-car.h

+/*
+ * This header provides Tegra124-specific constants for binding
+ * nvidia,tegra124-car.
+ */
+
+#ifndef _DT_BINDINGS_RESET_TEGRA124_CAR_H
+#define _DT_BINDINGS_RESET_TEGRA124_CAR_H
+
+#define TEGRA124_RESET(x)		(6 * 32 + (x))
+#define TEGRA124_RST_DFLL_DVCO		TEGRA124_RESET(0)
+
+#endif	/* _DT_BINDINGS_RESET_TEGRA124_CAR_H */