Re: [PATCH 07/19] clk: tegra: dfll: support PWM regulator control

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On 04/12/2018 09:25, Joseph Lo wrote:
> The DFLL hardware supports two modes (I2C and PWM) for voltage control
> when requesting a frequency. In this patch, we introduce PWM mode support.
> 
> To support that, we re-organize the LUT for unifying the table for both
> cases of I2C and PWM mode. And generate that based on regulator info.
> For the PWM-based regulator, we get this info from DT. And do the same as
> the case of I2C LUT, which can help to map the PMIC voltage ID and voltages
> that the regulator supported.
> 
> The other parts are the support code for initializing the DFLL hardware
> to support PWM mode. Also, the register debugfs file is slightly
> reworked to only show the i2c registers when I2C mode is in use.
> 
> Based on the work of Peter De Schrijver <pdeschrijver@xxxxxxxxxx>.
> 
> Signed-off-by: Joseph Lo <josephl@xxxxxxxxxx>
> ---
>  drivers/clk/tegra/clk-dfll.c | 431 ++++++++++++++++++++++++++++++-----
>  1 file changed, 368 insertions(+), 63 deletions(-)
> 
> diff --git a/drivers/clk/tegra/clk-dfll.c b/drivers/clk/tegra/clk-dfll.c
> index 609e363dabf8..c294a2989f31 100644
> --- a/drivers/clk/tegra/clk-dfll.c
> +++ b/drivers/clk/tegra/clk-dfll.c
> @@ -1,7 +1,7 @@
>  /*
>   * clk-dfll.c - Tegra DFLL clock source common code
>   *
> - * Copyright (C) 2012-2014 NVIDIA Corporation. All rights reserved.
> + * Copyright (C) 2012-2018 NVIDIA Corporation. All rights reserved.
>   *
>   * Aleksandr Frid <afrid@xxxxxxxxxx>
>   * Paul Walmsley <pwalmsley@xxxxxxxxxx>
> @@ -47,6 +47,7 @@
>  #include <linux/kernel.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
> +#include <linux/pinctrl/consumer.h>
>  #include <linux/pm_opp.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/regmap.h>
> @@ -243,6 +244,12 @@ enum dfll_tune_range {
>  	DFLL_TUNE_LOW = 1,
>  };
>  
> +
> +enum tegra_dfll_pmu_if {
> +	TEGRA_DFLL_PMU_I2C = 0,
> +	TEGRA_DFLL_PMU_PWM = 1,
> +};
> +
>  /**
>   * struct dfll_rate_req - target DFLL rate request data
>   * @rate: target frequency, after the postscaling
> @@ -294,16 +301,25 @@ struct tegra_dfll {
>  	u32				ci;
>  	u32				cg;
>  	bool				cg_scale;
> +	u32				reg_init_uV;
>  
>  	/* I2C interface parameters */
>  	u32				i2c_fs_rate;
>  	u32				i2c_reg;
>  	u32				i2c_slave_addr;
>  
> -	/* i2c_lut array entries are regulator framework selectors */
> -	unsigned			i2c_lut[MAX_DFLL_VOLTAGES];
> -	int				i2c_lut_size;
> -	u8				lut_min, lut_max, lut_safe;
> +	/* lut array entries are regulator framework selectors or PWM values*/
> +	unsigned			lut[MAX_DFLL_VOLTAGES];
> +	unsigned			lut_uv[MAX_DFLL_VOLTAGES];
> +	int				lut_size;
> +	u8				lut_bottom, lut_min, lut_max, lut_safe;
> +
> +	/* PWM interface */
> +	enum tegra_dfll_pmu_if		pmu_if;
> +	unsigned long			pwm_rate;
> +	struct pinctrl			*pwm_pin;
> +	struct pinctrl_state		*pwm_enable_state;
> +	struct pinctrl_state		*pwm_disable_state;
>  };
>  
>  #define clk_hw_to_dfll(_hw) container_of(_hw, struct tegra_dfll, dfll_clk_hw)
> @@ -489,6 +505,34 @@ static void dfll_set_mode(struct tegra_dfll *td,
>  	dfll_wmb(td);
>  }
>  
> +/*
> + * DVCO rate control
> + */
> +
> +static unsigned long get_dvco_rate_below(struct tegra_dfll *td, u8 out_min)
> +{
> +	struct dev_pm_opp *opp;
> +	unsigned long rate, prev_rate;
> +	int uv, min_uv;
> +
> +	min_uv = td->lut_uv[out_min];
> +	for (rate = 0, prev_rate = 0; ; rate++) {
> +		opp = dev_pm_opp_find_freq_ceil(td->soc->dev, &rate);
> +		if (IS_ERR(opp))
> +			break;
> +
> +		uv = dev_pm_opp_get_voltage(opp);

Can you fix the type of 'uv' here? It should be unsigned long.

Cheers
Jon

-- 
nvpublic



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