linux-kernel - [PATCH v6 18/25] clk: tegra: pll: Add logic for SS

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Message-ID: <1434662920-21469-19-git-send-email-rklein@nvidia.com>
Date:	Thu, 18 Jun 2015 17:28:33 -0400
From:	Rhyland Klein <rklein@...dia.com>
To:	Peter De Schrijver <pdeschrijver@...dia.com>,
	Thierry Reding <thierry.reding@...il.com>
CC:	Mike Turquette <mturquette@...aro.org>,
	Stephen Warren <swarren@...dotorg.org>,
	Stephen Boyd <sboyd@...eaurora.org>,
	Alexandre Courbot <gnurou@...il.com>,
	Bill Huang <bilhuang@...dia.com>, Jim Lin <jilin@...dia.com>,
	Benson Leung <bleung@...omium.org>, linux-clk@...r.kernel.org,
	linux-tegra@...r.kernel.org, linux-kernel@...r.kernel.org,
	Rhyland Klein <rklein@...dia.com>
Subject: [PATCH v6 18/25] clk: tegra: pll: Add logic for SS

From: Bill Huang <bilhuang@...dia.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 <bilhuang@...dia.com>
Signed-off-by: Rhyland Klein <rklein@...dia.com>
---
v5:
  - Reorderd Patch so set_defaults logic is present already

 drivers/clk/tegra/clk-pll.c |   25 ++++++++++++++++++++++++-
 drivers/clk/tegra/clk.h     |    4 ++++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/tegra/clk-pll.c b/drivers/clk/tegra/clk-pll.c
index c6cb22cebac1..da356fcc7eeb 100644
--- a/drivers/clk/tegra/clk-pll.c
+++ b/drivers/clk/tegra/clk-pll.c
@@ -649,6 +649,26 @@ 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_reg) {
+		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_reg) {
+		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)
 {
@@ -667,8 +687,10 @@ static int _program_pll(struct clk_hw *hw, struct tegra_clk_pll_freq_table *cfg,
 			return 0;
 	}
 
-	if (state)
+	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);
@@ -681,6 +703,7 @@ 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 d29d095659a2..87239298043c 100644
--- a/drivers/clk/tegra/clk.h
+++ b/drivers/clk/tegra/clk.h
@@ -184,6 +184,8 @@ struct tegra_clk_pll;
  * @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
+ * @ssc_ctrl_reg:		Register offset where SSC settings are
+ * @ssc_ctrl_en_mask:		Mask of SSC enable bit
  * @aux_reg:			AUX register offset
  * @dyn_ramp_reg:		Dynamic ramp control register offset
  * @ext_misc_reg:		Miscellaneous control register offsets
@@ -262,6 +264,8 @@ 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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