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Message-ID: <20150430101225.GU3097@tbergstrom-lnx.Nvidia.com>
Date: Thu, 30 Apr 2015 13:12:25 +0300
From: Peter De Schrijver <pdeschrijver@...dia.com>
To: Rhyland Klein <rklein@...dia.com>
CC: Mike Turquette <mturquette@...aro.org>,
Stephen Warren <swarren@...dotorg.org>,
Stephen Boyd <sboyd@...eaurora.org>,
Thierry Reding <thierry.reding@...il.com>,
Alexandre Courbot <gnurou@...il.com>,
<linux-clk@...r.kernel.org>, <linux-tegra@...r.kernel.org>,
<linux-kernel@...r.kernel.org>, Bill Huang <bilhuang@...dia.com>
Subject: Re: [PATCH v2 16/19] clk: tegra: pll: Add Set_default logic
On Wed, Apr 29, 2015 at 01:21:46PM -0400, Rhyland Klein wrote:
> From: Bill Huang <bilhuang@...dia.com>
>
> Add logic which (if specified for a pll) can verify that a PLL is set
> to the proper default value and if not can set it. This can be
> specified per PLL as each will have different default values.
>
Why can't we just set the default values at init time?
> Signed-off-by: Bill Huang <bilhuang@...dia.com>
> ---
> v2:
> - Remove MACRO for PLL_MISC_CHECK_DEFAULT as suggested, and instead
> the tegra210 driver will include an inline version of this function.
>
> drivers/clk/tegra/clk-pll.c | 46 ++++++++++++++++++++++++++++++++-----------
> drivers/clk/tegra/clk.h | 2 ++
> 2 files changed, 37 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/clk/tegra/clk-pll.c b/drivers/clk/tegra/clk-pll.c
> index 00f0e621533a..28a2376cd8a7 100644
> --- a/drivers/clk/tegra/clk-pll.c
> +++ b/drivers/clk/tegra/clk-pll.c
> @@ -658,15 +658,28 @@ static int _program_pll(struct clk_hw *hw, struct tegra_clk_pll_freq_table *cfg,
> unsigned long rate)
> {
> struct tegra_clk_pll *pll = to_clk_pll(hw);
> + struct tegra_clk_pll_freq_table old_cfg;
> int state, ret = 0;
>
> state = clk_pll_is_enabled(hw);
>
> + _get_pll_mnp(pll, &old_cfg);
> +
> + if (state && pll->params->defaults_set && pll->params->dyn_ramp &&
> + (cfg->m == old_cfg.m) && (cfg->p == old_cfg.p)) {
> + ret = pll->params->dyn_ramp(pll, cfg);
> + if (!ret)
> + return 0;
> + }
> +
> if (state) {
> pll_clk_stop_ss(pll);
> _clk_pll_disable(hw);
> }
>
> + if (!pll->params->defaults_set && pll->params->set_defaults)
> + pll->params->set_defaults(pll);
> +
> _update_pll_mnp(pll, cfg);
>
> if (pll->params->flags & TEGRA_PLL_HAS_CPCON)
> @@ -1526,6 +1539,9 @@ static struct clk *_tegra_clk_register_pll(struct tegra_clk_pll *pll,
> if (!pll->params->calc_rate)
> pll->params->calc_rate = _calc_rate;
>
> + if (pll->params->set_defaults)
> + pll->params->set_defaults(pll);
> +
> /* Data in .init is copied by clk_register(), so stack variable OK */
> pll->hw.init = &init;
>
> @@ -1644,7 +1660,6 @@ struct clk *tegra_clk_register_pllxc(const char *name, const char *parent_name,
> struct tegra_clk_pll *pll;
> struct clk *clk, *parent;
> unsigned long parent_rate;
> - int err;
> u32 val, val_iddq;
>
> parent = __clk_lookup(parent_name);
> @@ -1665,18 +1680,27 @@ struct clk *tegra_clk_register_pllxc(const char *name, const char *parent_name,
> pll_params->vco_min = pll_params->adjust_vco(pll_params,
> parent_rate);
>
> - err = _setup_dynamic_ramp(pll_params, clk_base, parent_rate);
> - if (err)
> - return ERR_PTR(err);
> + /*
> + * If the pll has a set_defaults callback, it will take care of
> + * configuring dynamic ramping and setting IDDQ in that path.
> + */
> + if (!pll_params->set_defaults) {
> + int err;
>
> - val = readl_relaxed(clk_base + pll_params->base_reg);
> - val_iddq = readl_relaxed(clk_base + pll_params->iddq_reg);
> + err = _setup_dynamic_ramp(pll_params, clk_base, parent_rate);
> + if (err)
> + return ERR_PTR(err);
>
> - if (val & PLL_BASE_ENABLE)
> - WARN_ON(val_iddq & BIT(pll_params->iddq_bit_idx));
> - else {
> - val_iddq |= BIT(pll_params->iddq_bit_idx);
> - writel_relaxed(val_iddq, clk_base + pll_params->iddq_reg);
> + val = readl_relaxed(clk_base + pll_params->base_reg);
> + val_iddq = readl_relaxed(clk_base + pll_params->iddq_reg);
> +
> + if (val & PLL_BASE_ENABLE)
> + WARN_ON(val_iddq & BIT(pll_params->iddq_bit_idx));
> + else {
> + val_iddq |= BIT(pll_params->iddq_bit_idx);
> + writel_relaxed(val_iddq,
> + clk_base + pll_params->iddq_reg);
> + }
> }
>
> pll = _tegra_init_pll(clk_base, pmc, pll_params, lock);
> diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h
> index 850521d42be6..84c417576c18 100644
> --- a/drivers/clk/tegra/clk.h
> +++ b/drivers/clk/tegra/clk.h
> @@ -239,6 +239,7 @@ struct tegra_clk_pll_params {
> int stepb_shift;
> int lock_delay;
> int max_p;
> + bool defaults_set;
> struct pdiv_map *pdiv_tohw;
> struct div_nmp *div_nmp;
> struct tegra_clk_pll_freq_table *freq_table;
> @@ -254,6 +255,7 @@ struct tegra_clk_pll_params {
> unsigned long parent_rate);
> int (*dyn_ramp)(struct tegra_clk_pll *pll,
> struct tegra_clk_pll_freq_table *cfg);
> + void (*set_defaults)(struct tegra_clk_pll *pll);
> };
>
> #define TEGRA_PLL_USE_LOCK BIT(0)
> --
> 1.7.9.5
>
--
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