[PATCH v3 09/20] clk: tegra: pll: Add logic for SS

From: Rhyland Klein
Date: Fri May 01 2015 - 14:59:07 EST


From: Bill Huang <bilhuang@xxxxxxxxxx>

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 <bilhuang@xxxxxxxxxx>
---
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 ef5754f64622..f3c1f07d5332 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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