Re: [PATCH 06/19] clk: tegra: dfll: CVB calculation alignment with the regulator

[Jon Hunter <jonathanh@nvidia.com>]

On 04/12/2018 09:25, Joseph Lo wrote:
> The CVB table contains calibration data for the CPU DFLL based on
> process charaterization. The regulator step and offset parameters depend
> on the regulator supplying vdd-cpu , not on the specific Tegra SKU.
> 
> When using a PWM controlled regulator, the voltage step and offset are
> determined by the regulator type in use. This is specified in DT. When
> using an I2C controlled regulator, we can retrieve them from CPU regulator
> or DT (if specified). Then pass this information to the CVB table
> calculation function.
> 
> Based on the work done of "Peter De Schrijver <pdeschrijver@nvidia.com>"
> and "Alex Frid <afrid@nvidia.com>".
> 
> Signed-off-by: Joseph Lo <josephl@nvidia.com>
> ---
>  drivers/clk/tegra/clk-dfll.h               |  6 +-
>  drivers/clk/tegra/clk-tegra124-dfll-fcpu.c | 65 ++++++++++++++++++++--
>  drivers/clk/tegra/cvb.c                    | 12 ++--
>  drivers/clk/tegra/cvb.h                    |  6 +-
>  4 files changed, 75 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/clk/tegra/clk-dfll.h b/drivers/clk/tegra/clk-dfll.h
> index 83352c8078f2..ecc43cb9b6f1 100644
> --- a/drivers/clk/tegra/clk-dfll.h
> +++ b/drivers/clk/tegra/clk-dfll.h
> @@ -1,6 +1,6 @@
>  /*
>   * clk-dfll.h - prototypes and macros for the Tegra DFLL clocksource driver
> - * Copyright (C) 2013 NVIDIA Corporation.  All rights reserved.
> + * Copyright (C) 2013-2018 NVIDIA Corporation.  All rights reserved.
>   *
>   * Aleksandr Frid <afrid@nvidia.com>
>   * Paul Walmsley <pwalmsley@nvidia.com>
> @@ -22,11 +22,14 @@
>  #include <linux/reset.h>
>  #include <linux/types.h>
>  
> +#include "cvb.h"
> +
>  /**
>   * struct tegra_dfll_soc_data - SoC-specific hooks/integration for the DFLL driver
>   * @dev: struct device * that holds the OPP table for the DFLL
>   * @max_freq: maximum frequency supported on this SoC
>   * @cvb: CPU frequency table for this SoC
> + * @alignment: parameters of the regulator step and offset
>   * @init_clock_trimmers: callback to initialize clock trimmers
>   * @set_clock_trimmers_high: callback to tune clock trimmers for high voltage
>   * @set_clock_trimmers_low: callback to tune clock trimmers for low voltage
> @@ -35,6 +38,7 @@ struct tegra_dfll_soc_data {
>  	struct device *dev;
>  	unsigned long max_freq;
>  	const struct cvb_table *cvb;
> +	struct rail_alignment alignment;
>  
>  	void (*init_clock_trimmers)(void);
>  	void (*set_clock_trimmers_high)(void);
> diff --git a/drivers/clk/tegra/clk-tegra124-dfll-fcpu.c b/drivers/clk/tegra/clk-tegra124-dfll-fcpu.c
> index 1a2cc113e5c8..071a5c674832 100644
> --- a/drivers/clk/tegra/clk-tegra124-dfll-fcpu.c
> +++ b/drivers/clk/tegra/clk-tegra124-dfll-fcpu.c
> @@ -23,6 +23,7 @@
>  #include <linux/init.h>
>  #include <linux/of_device.h>
>  #include <linux/platform_device.h>
> +#include <linux/regulator/consumer.h>
>  #include <soc/tegra/fuse.h>
>  
>  #include "clk.h"
> @@ -50,9 +51,6 @@ static const struct cvb_table tegra124_cpu_cvb_tables[] = {
>  		.process_id = -1,
>  		.min_millivolts = 900,
>  		.max_millivolts = 1260,
> -		.alignment = {
> -			.step_uv = 10000, /* 10mV */
> -		},

What happens for tegra124-jetson-tk1 when we remove this?

>  		.speedo_scale = 100,
>  		.voltage_scale = 1000,
>  		.entries = {
> @@ -105,11 +103,43 @@ static const struct of_device_id tegra124_dfll_fcpu_of_match[] = {
>  	{ },
>  };
>  
> +static void get_alignment_from_dt(struct device *dev,
> +				  struct rail_alignment *align)
> +{
> +	align->step_uv = 0;
> +	align->offset_uv = 0;
> +
> +	if (of_property_read_u32(dev->of_node, "nvidia,align-step-uv",
> +				  &align->step_uv))
> +		align->step_uv = 0;
> +
> +	if (of_property_read_u32(dev->of_node,
> +				"nvidia,align-offset-uv", &align->offset_uv))
> +		align->offset_uv = 0;
> +}
> +
> +static int get_alignment_from_regulator(struct device *dev,
> +					 struct rail_alignment *align)
> +{
> +	struct regulator *reg = devm_regulator_get(dev, "vdd-cpu");
> +
> +	if (IS_ERR(reg))
> +		return PTR_ERR(reg);
> +
> +	align->offset_uv = regulator_list_voltage(reg, 0);
> +	align->step_uv = regulator_get_linear_step(reg);
> +
> +	devm_regulator_put(reg);
> +
> +	return 0;
> +}
> +
>  static int tegra124_dfll_fcpu_probe(struct platform_device *pdev)
>  {
>  	int process_id, speedo_id, speedo_value, err;
>  	struct tegra_dfll_soc_data *soc;
>  	const struct dfll_fcpu_data *fcpu_data;
> +	struct rail_alignment align;
>  
>  	fcpu_data = of_device_get_match_data(&pdev->dev);
>  	if (!fcpu_data)
> @@ -135,12 +165,37 @@ static int tegra124_dfll_fcpu_probe(struct platform_device *pdev)
>  		return -ENODEV;
>  	}
>  
> +	get_alignment_from_dt(&pdev->dev, &align);
> +	if (of_property_read_bool(pdev->dev.of_node, "nvidia,pwm-to-pmic")
> +		 && (!align.step_uv || !align.offset_uv)) {
> +		dev_info(&pdev->dev, "Missing required align data in DT");
> +		return -EINVAL;
> +	} else {

This 'else' clause is not necessary.

> +		if (!align.step_uv) {
> +			dev_info(&pdev->dev,
> +				 "no align data in DT, try from vdd-cpu\n");
> +			err = get_alignment_from_regulator(&pdev->dev, &align);

dev_warn

> +			if (err == -EPROBE_DEFER) {
> +				dev_info(&pdev->dev,
> +					 "defer probe to get vdd-cpu\n");

This dev_info is not necessary.

> +				return -EPROBE_DEFER;
> +			}
> +		}
> +	}
> +
> +	if (!align.step_uv) {
> +		dev_err(&pdev->dev, "missing step uv\n");
> +		return -EINVAL;
> +	}
> +
>  	soc->max_freq = fcpu_data->cpu_max_freq_table[speedo_id];
>  
>  	soc->cvb = tegra_cvb_add_opp_table(soc->dev, fcpu_data->cpu_cvb_tables,
>  					   fcpu_data->cpu_cvb_tables_size,
> -					   process_id, speedo_id, speedo_value,
> -					   soc->max_freq);
> +					   &align, process_id, speedo_id,
> +					   speedo_value, soc->max_freq);
> +	soc->alignment = align;
> +
>  	if (IS_ERR(soc->cvb)) {
>  		dev_err(&pdev->dev, "couldn't add OPP table: %ld\n",
>  			PTR_ERR(soc->cvb));
> diff --git a/drivers/clk/tegra/cvb.c b/drivers/clk/tegra/cvb.c
> index da9e8e7b5ce5..81dcb97a9e0a 100644
> --- a/drivers/clk/tegra/cvb.c
> +++ b/drivers/clk/tegra/cvb.c
> @@ -1,7 +1,7 @@
>  /*
>   * Utility functions for parsing Tegra CVB voltage tables
>   *
> - * Copyright (C) 2012-2014 NVIDIA Corporation.  All rights reserved.
> + * Copyright (C) 2012-2018 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
> @@ -62,9 +62,9 @@ static int round_voltage(int mv, const struct rail_alignment *align, int up)
>  }
>  
>  static int build_opp_table(struct device *dev, const struct cvb_table *table,
> +			   struct rail_alignment *align,
>  			   int speedo_value, unsigned long max_freq)
>  {
> -	const struct rail_alignment *align = &table->alignment;
>  	int i, ret, dfll_mv, min_mv, max_mv;
>  
>  	min_mv = round_voltage(table->min_millivolts, align, UP);
> @@ -109,8 +109,9 @@ static int build_opp_table(struct device *dev, const struct cvb_table *table,
>   */
>  const struct cvb_table *
>  tegra_cvb_add_opp_table(struct device *dev, const struct cvb_table *tables,
> -			size_t count, int process_id, int speedo_id,
> -			int speedo_value, unsigned long max_freq)
> +			size_t count, struct rail_alignment *align,
> +			int process_id, int speedo_id, int speedo_value,
> +			unsigned long max_freq)
>  {
>  	size_t i;
>  	int ret;
> @@ -124,7 +125,8 @@ tegra_cvb_add_opp_table(struct device *dev, const struct cvb_table *tables,
>  		if (table->process_id != -1 && table->process_id != process_id)
>  			continue;
>  
> -		ret = build_opp_table(dev, table, speedo_value, max_freq);
> +		ret = build_opp_table(dev, table, align, speedo_value,
> +				      max_freq);
>  		return ret ? ERR_PTR(ret) : table;
>  	}
>  
> diff --git a/drivers/clk/tegra/cvb.h b/drivers/clk/tegra/cvb.h
> index c1f077993b2a..bcf15a089b93 100644
> --- a/drivers/clk/tegra/cvb.h
> +++ b/drivers/clk/tegra/cvb.h
> @@ -49,7 +49,6 @@ struct cvb_table {
>  
>  	int min_millivolts;
>  	int max_millivolts;
> -	struct rail_alignment alignment;
>  
>  	int speedo_scale;
>  	int voltage_scale;
> @@ -59,8 +58,9 @@ struct cvb_table {
>  
>  const struct cvb_table *
>  tegra_cvb_add_opp_table(struct device *dev, const struct cvb_table *cvb_tables,
> -			size_t count, int process_id, int speedo_id,
> -			int speedo_value, unsigned long max_freq);
> +			size_t count, struct rail_alignment *align,
> +			int process_id, int speedo_id, int speedo_value,
> +			unsigned long max_freq);
>  void tegra_cvb_remove_opp_table(struct device *dev,
>  				const struct cvb_table *table,
>  				unsigned long max_freq);
> 

-- 
nvpublic

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