From d907f4b4a178b7bbc8edc67191f63155d6492b80 Mon Sep 17 00:00:00 2001 From: Rhyland Klein Date: Thu, 18 Jun 2015 17:28:24 -0400 Subject: [PATCH] clk: tegra: pll: Add logic for handling SDM data This adds logic for taking SDM_DIN (Sigma Delta Modulator) setting into the equation to calculate the effective N value for PLL which supports fractional divider. The effective N = NDIV + 1/2 + SDM_DIN/2^13, where NDIV is the integer feedback divider. Reviewed-by: Benson Leung Signed-off-by: Rhyland Klein Signed-off-by: Thierry Reding --- drivers/clk/tegra/clk-pll.c | 66 ++++++++++++++++++++++++++++++++++++- drivers/clk/tegra/clk.h | 15 ++++++++- 2 files changed, 79 insertions(+), 2 deletions(-) diff --git a/drivers/clk/tegra/clk-pll.c b/drivers/clk/tegra/clk-pll.c index 54046266bdfb..20fd2d8dbad3 100644 --- a/drivers/clk/tegra/clk-pll.c +++ b/drivers/clk/tegra/clk-pll.c @@ -187,17 +187,23 @@ #define pll_readl_base(p) pll_readl(p->params->base_reg, p) #define pll_readl_misc(p) pll_readl(p->params->misc_reg, p) #define pll_override_readl(offset, p) readl_relaxed(p->pmc + offset) +#define pll_readl_sdm_din(p) pll_readl(p->params->sdm_din_reg, p) +#define pll_readl_sdm_ctrl(p) pll_readl(p->params->sdm_ctrl_reg, p) #define pll_writel(val, offset, p) writel_relaxed(val, p->clk_base + offset) #define pll_writel_base(val, p) pll_writel(val, p->params->base_reg, p) #define pll_writel_misc(val, p) pll_writel(val, p->params->misc_reg, p) #define pll_override_writel(val, offset, p) writel(val, p->pmc + offset) +#define pll_writel_sdm_din(val, p) pll_writel(val, p->params->sdm_din_reg, p) +#define pll_writel_sdm_ctrl(val, p) pll_writel(val, p->params->sdm_ctrl_reg, p) #define mask(w) ((1 << (w)) - 1) #define divm_mask(p) mask(p->params->div_nmp->divm_width) #define divn_mask(p) mask(p->params->div_nmp->divn_width) #define divp_mask(p) (p->params->flags & TEGRA_PLLU ? PLLU_POST_DIVP_MASK :\ mask(p->params->div_nmp->divp_width)) +#define sdm_din_mask(p) p->params->sdm_din_mask +#define sdm_en_mask(p) p->params->sdm_ctrl_en_mask #define divm_shift(p) (p)->params->div_nmp->divm_shift #define divn_shift(p) (p)->params->div_nmp->divn_shift @@ -211,6 +217,9 @@ #define divn_max(p) (divn_mask(p)) #define divp_max(p) (1 << (divp_mask(p))) +#define sdin_din_to_data(din) ((u16)((din) ? : 0xFFFFU)) +#define sdin_data_to_din(dat) (((dat) == 0xFFFFU) ? 0 : (s16)dat) + static struct div_nmp default_nmp = { .divn_shift = PLL_BASE_DIVN_SHIFT, .divn_width = PLL_BASE_DIVN_WIDTH, @@ -429,6 +438,7 @@ static int _get_table_rate(struct clk_hw *hw, cfg->n = sel->n; cfg->p = sel->p; cfg->cpcon = sel->cpcon; + cfg->sdm_data = sel->sdm_data; return 0; } @@ -495,6 +505,42 @@ static int _calc_rate(struct clk_hw *hw, struct tegra_clk_pll_freq_table *cfg, return 0; } +/* + * SDM (Sigma Delta Modulator) divisor is 16-bit 2's complement signed number + * within (-2^12 ... 2^12-1) range. Represented in PLL data structure as + * unsigned 16-bit value, with "0" divisor mapped to 0xFFFF. Data "0" is used + * to indicate that SDM is disabled. + * + * Effective ndiv value when SDM is enabled: ndiv + 1/2 + sdm_din/2^13 + */ +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; + bool enabled; + + 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); + enabled = (val & sdm_en_mask(pll)); + + if (cfg->sdm_data == 0 && enabled) + val &= ~pll->params->sdm_ctrl_en_mask; + + if (cfg->sdm_data != 0 && !enabled) + val |= pll->params->sdm_ctrl_en_mask; + + pll_writel_sdm_ctrl(val, pll); +} + static void _update_pll_mnp(struct tegra_clk_pll *pll, struct tegra_clk_pll_freq_table *cfg) { @@ -527,6 +573,8 @@ static void _update_pll_mnp(struct tegra_clk_pll *pll, (cfg->p << divp_shift(pll)); pll_writel_base(val, pll); + + clk_pll_set_sdm_data(&pll->hw, cfg); } } @@ -552,6 +600,14 @@ 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); + val &= sdm_din_mask(pll); + cfg->sdm_data = sdin_din_to_data(val); + } + } } } @@ -633,7 +689,8 @@ static int clk_pll_set_rate(struct clk_hw *hw, unsigned long rate, _get_pll_mnp(pll, &old_cfg); - if (old_cfg.m != cfg.m || old_cfg.n != cfg.n || old_cfg.p != cfg.p) + if (old_cfg.m != cfg.m || old_cfg.n != cfg.n || old_cfg.p != cfg.p || + old_cfg.sdm_data != cfg.sdm_data) ret = _program_pll(hw, &cfg, rate); if (pll->lock) @@ -697,6 +754,9 @@ static unsigned long clk_pll_recalc_rate(struct clk_hw *hw, pdiv = 1; } + if (pll->params->set_gain) + pll->params->set_gain(&cfg); + cfg.m *= pdiv; rate *= cfg.n; @@ -978,6 +1038,7 @@ static int clk_pllxc_set_rate(struct clk_hw *hw, unsigned long rate, static long clk_pll_ramp_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *prate) { + struct tegra_clk_pll *pll = to_clk_pll(hw); struct tegra_clk_pll_freq_table cfg; int ret, p_div; u64 output_rate = *prate; @@ -990,6 +1051,9 @@ static long clk_pll_ramp_round_rate(struct clk_hw *hw, unsigned long rate, if (p_div < 0) return p_div; + if (pll->params->set_gain) + pll->params->set_gain(&cfg); + output_rate *= cfg.n; do_div(output_rate, cfg.m * p_div); diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h index 488ee677e15b..72368e1ed46a 100644 --- a/drivers/clk/tegra/clk.h +++ b/drivers/clk/tegra/clk.h @@ -110,14 +110,16 @@ struct clk *tegra_clk_register_mc(const char *name, const char *parent_name, * @m: input divider * @p: post divider * @cpcon: charge pump current + * @sdm_data: fraction divider setting (0 = disabled) */ struct tegra_clk_pll_freq_table { unsigned long input_rate; unsigned long output_rate; - u16 n; + u32 n; u16 m; u8 p; u8 cpcon; + u16 sdm_data; }; /** @@ -174,6 +176,10 @@ struct div_nmp { * @lock_enable_bit_idx: Bit index to enable PLL lock * @iddq_reg: PLL IDDQ register offset * @iddq_bit_idx: Bit index to enable PLL IDDQ + * @sdm_din_reg: Register offset where SDM settings are + * @sdm_din_mask: Mask of SDM divider bits + * @sdm_ctrl_reg: Register offset where SDM enable is + * @sdm_ctrl_en_mask: Mask of SDM enable bit * @aux_reg: AUX register offset * @dyn_ramp_reg: Dynamic ramp control register offset * @ext_misc_reg: Miscellaneous control register offsets @@ -188,6 +194,8 @@ 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 + * @set_gain: Callback to adjust N div for SDM enabled + * PLL's based on fractional divider value. * * Flags: * TEGRA_PLL_USE_LOCK - This flag indicated to use lock bits for @@ -225,6 +233,10 @@ 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; u32 aux_reg; u32 dyn_ramp_reg; u32 ext_misc_reg[MAX_PLL_MISC_REG_COUNT]; @@ -239,6 +251,7 @@ 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); }; #define TEGRA_PLL_USE_LOCK BIT(0)