[PATCH v4 09/20] clk: tegra: pll: Add logic for SS

[Rhyland Klein]

From: Bill Huang <bilhu...@nvidia.com>

Add some logic for Spread Spectrum control. It is used in conjuncture
with SDM fractional dividers. SSC has to be disabled when we configure
the divider settings.

Signed-off-by: Bill Huang <bilhu...@nvidia.com>
---
 drivers/clk/tegra/clk-pll.c |   25 ++++++++++++++++++++++++-
 drivers/clk/tegra/clk.h     |    2 ++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/tegra/clk-pll.c b/drivers/clk/tegra/clk-pll.c
index c64b75185d6b..2a559408cee1 100644
--- a/drivers/clk/tegra/clk-pll.c
+++ b/drivers/clk/tegra/clk-pll.c
@@ -621,6 +621,26 @@ static void _update_pll_cpcon(struct tegra_clk_pll *pll,
        pll_writel_misc(val, pll);
 }
 
+static void pll_clk_start_ss(struct tegra_clk_pll *pll)
+{
+       if (pll->params->defaults_set && pll->params->ssc_ctrl_en_mask) {
+               u32 val = pll_readl(pll->params->ssc_ctrl_reg, pll);
+
+               val |= pll->params->ssc_ctrl_en_mask;
+               pll_writel(val, pll->params->ssc_ctrl_reg, pll);
+       }
+}
+
+static void pll_clk_stop_ss(struct tegra_clk_pll *pll)
+{
+       if (pll->params->defaults_set && pll->params->ssc_ctrl_en_mask) {
+               u32 val = pll_readl(pll->params->ssc_ctrl_reg, pll);
+
+               val &= ~pll->params->ssc_ctrl_en_mask;
+               pll_writel(val, pll->params->ssc_ctrl_reg, pll);
+       }
+}
+
 static int _program_pll(struct clk_hw *hw, struct tegra_clk_pll_freq_table 
*cfg,
                        unsigned long rate)
 {
@@ -629,8 +649,10 @@ static int _program_pll(struct clk_hw *hw, struct 
tegra_clk_pll_freq_table *cfg,
 
        state = clk_pll_is_enabled(hw);
 
-       if (state)
+       if (state) {
+               pll_clk_stop_ss(pll);
                _clk_pll_disable(hw);
+       }
 
        _update_pll_mnp(pll, cfg);
 
@@ -640,6 +662,7 @@ static int _program_pll(struct clk_hw *hw, struct 
tegra_clk_pll_freq_table *cfg,
        if (state) {
                _clk_pll_enable(hw);
                ret = clk_pll_wait_for_lock(pll);
+               pll_clk_start_ss(pll);
        }
 
        return ret;
diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h
index eb8103ec335e..3f92f1ad3961 100644
--- a/drivers/clk/tegra/clk.h
+++ b/drivers/clk/tegra/clk.h
@@ -219,6 +219,8 @@ struct tegra_clk_pll_params {
        u32             sdm_din_mask;
        u32             sdm_ctrl_reg;
        u32             sdm_ctrl_en_mask;
+       u32             ssc_ctrl_reg;
+       u32             ssc_ctrl_en_mask;
        u32             aux_reg;
        u32             dyn_ramp_reg;
        u32             ext_misc_reg[MAX_PLL_MISC_REG_COUNT];
-- 
1.7.9.5

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