Add support to enable/disable the alpha pll using hwfsm

Signed-off-by: Rajendra Nayak <rna...@codeaurora.org>
---
 drivers/clk/qcom/clk-alpha-pll.c | 109 ++++++++++++++++++++++++++++++++++-----
 drivers/clk/qcom/clk-alpha-pll.h |   1 +
 2 files changed, 98 insertions(+), 12 deletions(-)

diff --git a/drivers/clk/qcom/clk-alpha-pll.c b/drivers/clk/qcom/clk-alpha-pll.c
index e6a03ea..bae31f9 100644
--- a/drivers/clk/qcom/clk-alpha-pll.c
+++ b/drivers/clk/qcom/clk-alpha-pll.c
@@ -62,9 +62,10 @@
 #define to_clk_alpha_pll_postdiv(_hw) container_of(to_clk_regmap(_hw), \
                                           struct clk_alpha_pll_postdiv, clkr)
 
-static int wait_for_pll(struct clk_alpha_pll *pll)
+static int wait_for_pll(struct clk_alpha_pll *pll, u32 mask, bool inverse,
+                       const char *action)
 {
-       u32 val, mask, off;
+       u32 val, off;
        int count;
        int ret;
        const char *name = clk_hw_get_name(&pll->clkr.hw);
@@ -74,26 +75,101 @@ static int wait_for_pll(struct clk_alpha_pll *pll)
        if (ret)
                return ret;
 
-       if (val & PLL_VOTE_FSM_ENA)
-               mask = PLL_ACTIVE_FLAG;
-       else
-               mask = PLL_LOCK_DET;
-
-       /* Wait for pll to enable. */
        for (count = 100; count > 0; count--) {
                ret = regmap_read(pll->clkr.regmap, off + PLL_MODE, &val);
                if (ret)
                        return ret;
-               if ((val & mask) == mask)
+               if (inverse && (val & mask))
+                       return 0;
+               else if ((val & mask) == mask)
                        return 0;
 
                udelay(1);
        }
 
-       WARN(1, "%s didn't enable after voting for it!\n", name);
+       WARN(1, "%s failed to %s!\n", name, action);
        return -ETIMEDOUT;
 }
 
+static int wait_for_pll_enable(struct clk_alpha_pll *pll, u32 mask)
+{
+       return wait_for_pll(pll, mask, 0, "enable");
+}
+
+static int wait_for_pll_disable(struct clk_alpha_pll *pll, u32 mask)
+{
+       return wait_for_pll(pll, mask, 1, "disable");
+}
+
+static int wait_for_pll_offline(struct clk_alpha_pll *pll, u32 mask)
+{
+       return wait_for_pll(pll, mask, 0, "offline");
+}
+
+/* alpha pll with hwfsm support */
+#define PLL_OFFLINE_REQ                BIT(7)
+#define PLL_FSM_ENA            BIT(20)
+#define PLL_OFFLINE_ACK                BIT(28)
+#define PLL_ACTIVE_FLAG                BIT(30)
+
+static int clk_alpha_pll_hwfsm_enable(struct clk_hw *hw)
+{
+       int ret;
+       u32 val, off;
+       struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
+
+       off = pll->offset;
+       ret = regmap_read(pll->clkr.regmap, off + PLL_MODE, &val);
+       if (ret)
+               return ret;
+
+       /* Enable HW FSM mode, clear OFFLINE request */
+       val |= PLL_FSM_ENA;
+       val &= ~PLL_OFFLINE_REQ;
+       ret = regmap_write(pll->clkr.regmap, off + PLL_MODE, val);
+       if (ret)
+               return ret;
+
+       /* Make sure enable request goes through before waiting for update */
+       mb();
+
+       ret = wait_for_pll_enable(pll, PLL_ACTIVE_FLAG);
+       if (ret)
+               return ret;
+
+       return 0;
+}
+
+static void clk_alpha_pll_hwfsm_disable(struct clk_hw *hw)
+{
+       int ret;
+       u32 val, off;
+       struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
+
+       off = pll->offset;
+       ret = regmap_read(pll->clkr.regmap, off + PLL_MODE, &val);
+       if (ret)
+               return;
+
+       /* Request PLL_OFFLINE and wait for ack */
+       ret = regmap_update_bits(pll->clkr.regmap, off + PLL_MODE,
+                                PLL_OFFLINE_REQ, PLL_OFFLINE_REQ);
+       if (ret)
+               return;
+
+       ret = wait_for_pll_offline(pll, PLL_OFFLINE_ACK);
+       if (ret)
+               return;
+
+       /* Disable hwfsm */
+       ret = regmap_update_bits(pll->clkr.regmap, off + PLL_MODE,
+                                PLL_FSM_ENA, 0);
+       if (ret)
+               return;
+
+       wait_for_pll_disable(pll, PLL_ACTIVE_FLAG);
+}
+
 static int clk_alpha_pll_enable(struct clk_hw *hw)
 {
        int ret;
@@ -112,7 +188,7 @@ static int clk_alpha_pll_enable(struct clk_hw *hw)
                ret = clk_enable_regmap(hw);
                if (ret)
                        return ret;
-               return wait_for_pll(pll);
+               return wait_for_pll_enable(pll, PLL_ACTIVE_FLAG);
        }
 
        /* Skip if already enabled */
@@ -136,7 +212,7 @@ static int clk_alpha_pll_enable(struct clk_hw *hw)
        if (ret)
                return ret;
 
-       ret = wait_for_pll(pll);
+       ret = wait_for_pll_enable(pll, PLL_LOCK_DET);
        if (ret)
                return ret;
 
@@ -300,6 +376,15 @@ const struct clk_ops clk_alpha_pll_ops = {
 };
 EXPORT_SYMBOL_GPL(clk_alpha_pll_ops);
 
+const struct clk_ops clk_alpha_pll_hwfsm_ops = {
+       .enable = clk_alpha_pll_hwfsm_enable,
+       .disable = clk_alpha_pll_hwfsm_disable,
+       .recalc_rate = clk_alpha_pll_recalc_rate,
+       .round_rate = clk_alpha_pll_round_rate,
+       .set_rate = clk_alpha_pll_set_rate,
+};
+EXPORT_SYMBOL_GPL(clk_alpha_pll_hwfsm_ops);
+
 static unsigned long
 clk_alpha_pll_postdiv_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
 {
diff --git a/drivers/clk/qcom/clk-alpha-pll.h b/drivers/clk/qcom/clk-alpha-pll.h
index 90ce201..f78bf4c 100644
--- a/drivers/clk/qcom/clk-alpha-pll.h
+++ b/drivers/clk/qcom/clk-alpha-pll.h
@@ -52,6 +52,7 @@ struct clk_alpha_pll_postdiv {
 };
 
 extern const struct clk_ops clk_alpha_pll_ops;
+extern const struct clk_ops clk_alpha_pll_hwfsm_ops;
 extern const struct clk_ops clk_alpha_pll_postdiv_ops;
 
 #endif
-- 
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