Re: [PATCH v4 08/20] clk: tegra: pll: Add logic for handling SDM data

From: Benson Leung
Date: Mon May 04 2015 - 19:01:41 EST


On Mon, May 4, 2015 at 9:37 AM, Rhyland Klein <rklein@xxxxxxxxxx> wrote:
> @@ -495,6 +505,28 @@ static int _calc_rate(struct clk_hw *hw, struct tegra_clk_pll_freq_table *cfg,
> return 0;
> }
>
> +static void clk_pll_set_sdm_data(struct clk_hw *hw,
> + struct tegra_clk_pll_freq_table *cfg)
> +{
> + struct tegra_clk_pll *pll = to_clk_pll(hw);
> + u32 val;
> +
> + if (!pll->params->sdm_din_reg)
> + return;
> +
> + if (cfg->sdm_data) {
> + val = pll_readl_sdm_din(pll) & (~sdm_din_mask(pll));
> + val |= sdin_data_to_din(cfg->sdm_data) & sdm_din_mask(pll);
> + pll_writel_sdm_din(val, pll);
> + }
> +
> + val = pll_readl_sdm_ctrl(pll);
> + if (!cfg->sdm_data != !(val & pll->params->sdm_ctrl_en_mask)) {

You can use sdm_en_mask(pll) here.

I'm not super clear about what you're trying to accomplish here with
!cfg->sdm_data != !(val & mask).
Are you just checking if the masked value is different from sdm_data,
but accounting for the integer widths being different (u16 vs u32)?

> + val ^= pll->params->sdm_ctrl_en_mask;

You can use sdm_en_mask(pll) here.

> + pll_writel_sdm_ctrl(val, pll);
> + }
> +}
> +

> @@ -552,6 +586,14 @@ static void _get_pll_mnp(struct tegra_clk_pll *pll,
> cfg->m = (val >> div_nmp->divm_shift) & divm_mask(pll);
> cfg->n = (val >> div_nmp->divn_shift) & divn_mask(pll);
> cfg->p = (val >> div_nmp->divp_shift) & divp_mask(pll);
> +
> + if (pll->params->sdm_din_reg) {
> + if (sdm_en_mask(pll) & pll_readl_sdm_ctrl(pll)) {
> + val = pll_readl_sdm_din(pll);
> + cfg->sdm_data = val & sdm_din_mask(pll);
> + cfg->sdm_data = sdin_din_to_data(cfg->sdm_data);

Maybe this is tighter?

val = pll_readl_sdm_din(pll);
val &= sdm_din_mask(pll);
cfg->sdm_data = sdin_din_to_data(val);

> @@ -697,6 +740,9 @@ static unsigned long clk_pll_recalc_rate(struct clk_hw *hw,
> pdiv = 1;
> }
>
> + if (pll->params->set_gain)
> + pll->params->set_gain(&cfg);
> +

It's not really clear from this commit alone how set_gain relates to
the sdm stuff.

> diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h
> index 8e7361886cf9..eb8103ec335e 100644
> --- a/drivers/clk/tegra/clk.h
> +++ b/drivers/clk/tegra/clk.h
> /**
> @@ -213,6 +215,10 @@ struct tegra_clk_pll_params {
> u32 lock_enable_bit_idx;
> u32 iddq_reg;
> u32 iddq_bit_idx;
> + u32 sdm_din_reg;
> + u32 sdm_din_mask;
> + u32 sdm_ctrl_reg;
> + u32 sdm_ctrl_en_mask;

Please add kerneldoc for these members as well.

> u32 aux_reg;
> u32 dyn_ramp_reg;
> u32 ext_misc_reg[MAX_PLL_MISC_REG_COUNT];
> @@ -227,6 +233,7 @@ struct tegra_clk_pll_params {
> struct div_nmp *div_nmp;
> struct tegra_clk_pll_freq_table *freq_table;
> unsigned long fixed_rate;
> + void (*set_gain)(struct tegra_clk_pll_freq_table *cfg);

This one too.

--
Benson Leung
Software Engineer, Chrom* OS
bleung@xxxxxxxxxxxx
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