diff options
author | Rhyland Klein <rklein@nvidia.com> | 2015-06-18 17:28:25 -0400 |
---|---|---|
committer | Thierry Reding <treding@nvidia.com> | 2015-11-20 18:05:03 +0100 |
commit | 407254da291c03c32109881ca8cbda5607714a8f (patch) | |
tree | e21fc008d1751f0ca5499e7728d9766c4ee95384 /drivers/clk/tegra | |
parent | d907f4b4a178b7bbc8edc67191f63155d6492b80 (diff) | |
download | linux-407254da291c03c32109881ca8cbda5607714a8f.tar.bz2 |
clk: tegra: pll: Add logic for out-of-table rates for T210
For Tegra210, the logic to calculate out-of-table rates is different
from previous generations. Add callbacks that can be overridden to
allow for different ways of calculating rates. Default to
_cal_rate when not specified.
This patch also includes a new flag which is used to set which method
of fixed_mdiv calculation is used. The new method for calculating the
fixed divider value for M can be more accurate especially when
fractional dividers are in play. This allows for older chipsets to use
the existing logic and new generations to use a newer version which
may work better for them.
Based on original work by Aleksandr Frid <afrid@nvidia.com>
Reviewed-by: Benson Leung <bleung@chromium.org>
Signed-off-by: Rhyland Klein <rklein@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Diffstat (limited to 'drivers/clk/tegra')
-rw-r--r-- | drivers/clk/tegra/clk-pll.c | 24 | ||||
-rw-r--r-- | drivers/clk/tegra/clk.h | 13 |
2 files changed, 35 insertions, 2 deletions
diff --git a/drivers/clk/tegra/clk-pll.c b/drivers/clk/tegra/clk-pll.c index 20fd2d8dbad3..fb3e3f67586c 100644 --- a/drivers/clk/tegra/clk-pll.c +++ b/drivers/clk/tegra/clk-pll.c @@ -678,7 +678,7 @@ static int clk_pll_set_rate(struct clk_hw *hw, unsigned long rate, } if (_get_table_rate(hw, &cfg, rate, parent_rate) && - _calc_rate(hw, &cfg, rate, parent_rate)) { + pll->params->calc_rate(hw, &cfg, rate, parent_rate)) { pr_err("%s: Failed to set %s rate %lu\n", __func__, clk_hw_get_name(hw), rate); WARN_ON(1); @@ -713,7 +713,7 @@ static long clk_pll_round_rate(struct clk_hw *hw, unsigned long rate, return clk_hw_get_rate(hw); if (_get_table_rate(hw, &cfg, rate, *prate) && - _calc_rate(hw, &cfg, rate, *prate)) + pll->params->calc_rate(hw, &cfg, rate, *prate)) return -EINVAL; return cfg.output_rate; @@ -903,12 +903,28 @@ const struct clk_ops tegra_clk_plle_ops = { static int _pll_fixed_mdiv(struct tegra_clk_pll_params *pll_params, unsigned long parent_rate) { + u16 mdiv = parent_rate / pll_params->cf_min; + + if (pll_params->flags & TEGRA_MDIV_NEW) + return (!pll_params->mdiv_default ? mdiv : + min(mdiv, pll_params->mdiv_default)); + + if (pll_params->mdiv_default) + return pll_params->mdiv_default; + if (parent_rate > pll_params->cf_max) return 2; else return 1; } +u16 tegra_pll_get_fixed_mdiv(struct clk_hw *hw, unsigned long input_rate) +{ + struct tegra_clk_pll *pll = to_clk_pll(hw); + + return (u16)_pll_fixed_mdiv(pll->params, input_rate); +} + static unsigned long _clip_vco_min(unsigned long vco_min, unsigned long parent_rate) { @@ -1483,6 +1499,10 @@ static struct clk *_tegra_clk_register_pll(struct tegra_clk_pll *pll, init.parent_names = (parent_name ? &parent_name : NULL); init.num_parents = (parent_name ? 1 : 0); + /* Default to _calc_rate if unspecified */ + if (!pll->params->calc_rate) + pll->params->calc_rate = _calc_rate; + /* Data in .init is copied by clk_register(), so stack variable OK */ pll->hw.init = &init; diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h index 72368e1ed46a..ae09a3139df2 100644 --- a/drivers/clk/tegra/clk.h +++ b/drivers/clk/tegra/clk.h @@ -194,8 +194,12 @@ struct div_nmp { * @div_nmp: offsets and widths on n, m and p fields * @freq_table: array of frequencies supported by PLL * @fixed_rate: PLL rate if it is fixed + * @mdiv_default: Default value for fixed mdiv for this PLL + * @round_p_to_pdiv: Callback used to round p to the closed pdiv * @set_gain: Callback to adjust N div for SDM enabled * PLL's based on fractional divider value. + * @calc_rate: Callback used to change how out of table + * rates (dividers and multipler) are calculated. * * Flags: * TEGRA_PLL_USE_LOCK - This flag indicated to use lock bits for @@ -217,6 +221,8 @@ struct div_nmp { * base register. * TEGRA_PLL_BYPASS - PLL has bypass bit * TEGRA_PLL_HAS_LOCK_ENABLE - PLL has bit to enable lock monitoring + * TEGRA_MDIV_NEW - Switch to new method for calculating fixed mdiv + * it may be more accurate (especially if SDM present) */ struct tegra_clk_pll_params { unsigned long input_min; @@ -251,7 +257,12 @@ struct tegra_clk_pll_params { struct div_nmp *div_nmp; struct tegra_clk_pll_freq_table *freq_table; unsigned long fixed_rate; + u16 mdiv_default; + u32 (*round_p_to_pdiv)(u32 p, u32 *pdiv); void (*set_gain)(struct tegra_clk_pll_freq_table *cfg); + int (*calc_rate)(struct clk_hw *hw, + struct tegra_clk_pll_freq_table *cfg, + unsigned long rate, unsigned long parent_rate); }; #define TEGRA_PLL_USE_LOCK BIT(0) @@ -265,6 +276,7 @@ struct tegra_clk_pll_params { #define TEGRA_PLL_LOCK_MISC BIT(8) #define TEGRA_PLL_BYPASS BIT(9) #define TEGRA_PLL_HAS_LOCK_ENABLE BIT(10) +#define TEGRA_MDIV_NEW BIT(11) /** * struct tegra_clk_pll - Tegra PLL clock @@ -690,5 +702,6 @@ void tegra114_clock_deassert_dfll_dvco_reset(void); typedef void (*tegra_clk_apply_init_table_func)(void); extern tegra_clk_apply_init_table_func tegra_clk_apply_init_table; int tegra_pll_wait_for_lock(struct tegra_clk_pll *pll); +u16 tegra_pll_get_fixed_mdiv(struct clk_hw *hw, unsigned long input_rate); #endif /* TEGRA_CLK_H */ |