Re: [PATCH v5 03/10] clk: tegra: Add PLL post divider table

[Prashant Gaikwad <pgaikwad-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>]

On Friday 01 February 2013 03:48 PM, Peter De Schrijver wrote:
> Some PLLs in Tegra114 don't use a power of 2 mapping for the post divider.
> Introduce a table based approach and switch PLLU to it.
>
> Signed-off-by: Peter De Schrijver <pdeschrijver-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> ---

Looks good to me.

Reviewed-by: Prashant Gaikwad <pgaikwad-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>

>   drivers/clk/tegra/clk-pll.c     |   38 ++++++++++++++++++++++++++++++++------
>   drivers/clk/tegra/clk-tegra20.c |    7 +++++++
>   drivers/clk/tegra/clk-tegra30.c |    7 +++++++
>   drivers/clk/tegra/clk.h         |   13 +++++++++++++
>   4 files changed, 59 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/clk/tegra/clk-pll.c b/drivers/clk/tegra/clk-pll.c
> index 3c3a25e..87d2f34 100644
> --- a/drivers/clk/tegra/clk-pll.c
> +++ b/drivers/clk/tegra/clk-pll.c
> @@ -258,6 +258,7 @@ static int _calc_rate(struct clk_hw *hw, struct tegra_clk_pll_freq_table *cfg,
>   		      unsigned long rate, unsigned long parent_rate)
>   {
>   	struct tegra_clk_pll *pll = to_clk_pll(hw);
> +	struct pdiv_map *p_tohw = pll->params->pdiv_tohw;
>   	unsigned long cfreq;
>   	u32 p_div = 0;
>   
> @@ -291,7 +292,6 @@ static int _calc_rate(struct clk_hw *hw, struct tegra_clk_pll_freq_table *cfg,
>   	     cfg->output_rate <<= 1)
>   		p_div++;
>   
> -	cfg->p = p_div;
>   	cfg->m = parent_rate / cfreq;
>   	cfg->n = cfg->output_rate / cfreq;
>   	cfg->cpcon = OUT_OF_TABLE_CPCON;
> @@ -304,8 +304,19 @@ static int _calc_rate(struct clk_hw *hw, struct tegra_clk_pll_freq_table *cfg,
>   		return -EINVAL;
>   	}
>   
> -	if (pll->flags & TEGRA_PLLU)
> -		cfg->p ^= 1;
> +	if (p_tohw) {
> +		p_div = 1 << p_div;
> +		while (p_tohw->pdiv) {
> +			if (p_div <= p_tohw->pdiv) {
> +				cfg->p = p_tohw->hw_val;
> +				break;
> +			}
> +			p_tohw++;
> +		}
> +		if (!p_tohw->pdiv)
> +			return -EINVAL;
> +	} else
> +		cfg->p = p_div;
>   
>   	return 0;
>   }
> @@ -452,8 +463,10 @@ static unsigned long clk_pll_recalc_rate(struct clk_hw *hw,
>   {
>   	struct tegra_clk_pll *pll = to_clk_pll(hw);
>   	struct tegra_clk_pll_freq_table cfg;
> +	struct pdiv_map *p_tohw = pll->params->pdiv_tohw;
>   	u32 val;
>   	u64 rate = parent_rate;
> +	int pdiv;
>   
>   	val = pll_readl_base(pll);
>   
> @@ -472,10 +485,23 @@ static unsigned long clk_pll_recalc_rate(struct clk_hw *hw,
>   
>   	_get_pll_mnp(pll, &cfg);
>   
> -	if (pll->flags & TEGRA_PLLU)
> -		cfg.p ^= 1;
> +	if (p_tohw) {
> +		while (p_tohw->pdiv) {
> +			if (cfg.p == p_tohw->hw_val) {
> +				pdiv = p_tohw->pdiv;
> +				break;
> +			}
> +			p_tohw++;
> +		}
> +
> +		if (!p_tohw->pdiv) {
> +			WARN_ON(1);
> +			pdiv = 1;
> +		}
> +	} else
> +		pdiv = 1 << cfg.p;
>   
> -	cfg.m *= 1 << cfg.p;
> +	cfg.m *= pdiv;
>   
>   	rate *= cfg.n;
>   	do_div(rate, cfg.m);
> diff --git a/drivers/clk/tegra/clk-tegra20.c b/drivers/clk/tegra/clk-tegra20.c
> index 30bd3fd..54c6777 100644
> --- a/drivers/clk/tegra/clk-tegra20.c
> +++ b/drivers/clk/tegra/clk-tegra20.c
> @@ -440,6 +440,12 @@ static struct tegra_clk_pll_params pll_d_params = {
>   	.lock_delay = 1000,
>   };
>   
> +static struct pdiv_map pllu_p[] = {
> +	{ .pdiv = 1, .hw_val = 1 },
> +	{ .pdiv = 2, .hw_val = 0 },
> +	{ .pdiv = 0, .hw_val = 0 },
> +};
> +
>   static struct tegra_clk_pll_params pll_u_params = {
>   	.input_min = 2000000,
>   	.input_max = 40000000,
> @@ -452,6 +458,7 @@ static struct tegra_clk_pll_params pll_u_params = {
>   	.lock_bit_idx = PLL_BASE_LOCK,
>   	.lock_enable_bit_idx = PLLDU_MISC_LOCK_ENABLE,
>   	.lock_delay = 1000,
> +	.pdiv_tohw = pllu_p,
>   };
>   
>   static struct tegra_clk_pll_params pll_x_params = {
> diff --git a/drivers/clk/tegra/clk-tegra30.c b/drivers/clk/tegra/clk-tegra30.c
> index 28a2997..078f9b8 100644
> --- a/drivers/clk/tegra/clk-tegra30.c
> +++ b/drivers/clk/tegra/clk-tegra30.c
> @@ -466,6 +466,12 @@ static struct tegra_clk_pll_freq_table pll_d_freq_table[] = {
>   	{ 0, 0, 0, 0, 0, 0 },
>   };
>   
> +static struct pdiv_map pllu_p[] = {
> +	{ .pdiv = 1, .hw_val = 1 },
> +	{ .pdiv = 2, .hw_val = 0 },
> +	{ .pdiv = 0, .hw_val = 0 },
> +};
> +
>   static struct tegra_clk_pll_freq_table pll_u_freq_table[] = {
>   	{ 12000000, 480000000, 960, 12, 0, 12},
>   	{ 13000000, 480000000, 960, 13, 0, 12},
> @@ -639,6 +645,7 @@ static struct tegra_clk_pll_params pll_u_params = {
>   	.lock_bit_idx = PLL_BASE_LOCK,
>   	.lock_enable_bit_idx = PLLDU_MISC_LOCK_ENABLE,
>   	.lock_delay = 1000,
> +	.pdiv_tohw = pllu_p,
>   };
>   
>   static struct tegra_clk_pll_params pll_x_params = {
> diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h
> index 3cff1df..1b9cbcd 100644
> --- a/drivers/clk/tegra/clk.h
> +++ b/drivers/clk/tegra/clk.h
> @@ -117,6 +117,17 @@ struct tegra_clk_pll_freq_table {
>   };
>   
>   /**
> + * struct pdiv_map - map post divider to hw value
> + *
> + * @pdiv:		post divider
> + * @hw_val:		value to be written to the PLL hw
> + */
> +struct pdiv_map {
> +	u8 pdiv;
> +	u8 hw_val;
> +};
> +
> +/**
>    * struct clk_pll_params - PLL parameters
>    *
>    * @input_min:			Minimum input frequency
> @@ -146,6 +157,8 @@ struct tegra_clk_pll_params {
>   	u32		lock_bit_idx;
>   	u32		lock_enable_bit_idx;
>   	int		lock_delay;
> +	int		max_p;
> +	struct pdiv_map *pdiv_tohw;
>   };
>   
>   /**
>