[PATCH v2 3/5] clk: samsung: Add set_rate() clk_ops for PLL35xx

[vikas.sajjan@linaro.org (Vikas Sajjan)]

From: Yadwinder Singh Brar <yadi.brar@samsung.com>

This patch add set_rate() and round_rate() for PLL35xx

Signed-off-by: Yadwinder Singh Brar <yadi.brar@samsung.com>
---
 drivers/clk/samsung/clk-pll.c |  103 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 102 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/samsung/clk-pll.c b/drivers/clk/samsung/clk-pll.c
index 4b3b3f5..1fba7ef 100644
--- a/drivers/clk/samsung/clk-pll.c
+++ b/drivers/clk/samsung/clk-pll.c
@@ -27,6 +27,36 @@ struct samsung_clk_pll {
 #define pll_writel(pll, val, offset)					\
 		__raw_writel(val, (void __iomem *)(pll->base + (offset)));
 
+static const struct samsung_pll_rate_table *samsung_get_pll_settings(
+				struct samsung_clk_pll *pll, unsigned long rate)
+{
+	const struct samsung_pll_rate_table  *rate_table = pll->rate_table;
+	int i;
+
+	for (i = 0; i < pll->rate_count; i++) {
+		if (rate == rate_table[i].rate)
+			return &rate_table[i];
+	}
+
+	return NULL;
+}
+
+static long samsung_pll_round_rate(struct clk_hw *hw,
+			unsigned long drate, unsigned long *prate)
+{
+	struct samsung_clk_pll *pll = to_clk_pll(hw);
+	const struct samsung_pll_rate_table *rate_table = pll->rate_table;
+	int i;
+
+	/* Assumming rate_table is in descending order */
+	for (i = 0; i < pll->rate_count; i++) {
+		if (drate >= rate_table[i].rate)
+			return rate_table[i].rate;
+	}
+
+	/* return minimum supported value */
+	return rate_table[i - 1].rate;
+}
 /*
  * PLL35xx Clock Type
  */
@@ -34,12 +64,17 @@ struct samsung_clk_pll {
 #define PLL35XX_CON0_OFFSET             0x100
 #define PLL35XX_CON1_OFFSET             0x104
 
+/* Maximum lock time can be 270 * PDIV cycles */
+#define PLL35XX_LOCK_FACTOR	270
+
 #define PLL35XX_MDIV_MASK       (0x3FF)
 #define PLL35XX_PDIV_MASK       (0x3F)
 #define PLL35XX_SDIV_MASK       (0x7)
+#define PLL35XX_LOCK_STAT_MASK  (0x1)
 #define PLL35XX_MDIV_SHIFT      (16)
 #define PLL35XX_PDIV_SHIFT      (8)
 #define PLL35XX_SDIV_SHIFT      (0)
+#define PLL35XX_LOCK_STAT_SHIFT (29)
 
 static unsigned long samsung_pll35xx_recalc_rate(struct clk_hw *hw,
 				unsigned long parent_rate)
@@ -59,8 +94,70 @@ static unsigned long samsung_pll35xx_recalc_rate(struct clk_hw *hw,
 	return (unsigned long)fvco;
 }
 
+static inline bool samsung_pll35xx_mp_change(u32 mdiv, u32 pdiv, u32 pll_con)
+{
+	if ((mdiv != ((pll_con >> PLL35XX_MDIV_SHIFT) & PLL35XX_MDIV_MASK)) ||
+		(pdiv != ((pll_con >> PLL35XX_PDIV_SHIFT) & PLL35XX_PDIV_MASK)))
+		return 1;
+	else
+		return 0;
+}
+
+static int samsung_pll35xx_set_rate(struct clk_hw *hw, unsigned long drate,
+					unsigned long prate)
+{
+	struct samsung_clk_pll *pll = to_clk_pll(hw);
+	const struct samsung_pll_rate_table *rate;
+	u32 tmp;
+
+	/* Get required rate settings from table */
+	rate = samsung_get_pll_settings(pll, drate);
+	if (!rate) {
+		pr_err("%s: Invalid rate : %lu for pll clk %s\n", __func__,
+			drate, __clk_get_name(hw->clk));
+		return -EINVAL;
+	}
+
+	tmp = pll_readl(pll, PLL35XX_CON0_OFFSET);
+
+	if (!(samsung_pll35xx_mp_change(rate->mdiv, rate->pdiv, tmp))) {
+		/* If only s change, change just s value only*/
+		tmp &= ~(PLL35XX_SDIV_MASK << PLL35XX_SDIV_SHIFT);
+		tmp |= rate->sdiv << PLL35XX_SDIV_SHIFT;
+		pll_writel(pll, tmp, PLL35XX_CON0_OFFSET);
+	} else {
+		/* Set PLL lock time. */
+		pll_writel(pll, rate->pdiv * PLL35XX_LOCK_FACTOR,
+				PLL35XX_LOCK_OFFSET);
+
+		/* Change PLL PMS values */
+		tmp &= ~((PLL35XX_MDIV_MASK << PLL35XX_MDIV_SHIFT) |
+				(PLL35XX_PDIV_MASK << PLL35XX_PDIV_SHIFT) |
+				(PLL35XX_SDIV_MASK << PLL35XX_SDIV_SHIFT));
+		tmp |= (rate->mdiv << PLL35XX_MDIV_SHIFT) |
+				(rate->pdiv << PLL35XX_PDIV_SHIFT) |
+				(rate->sdiv << PLL35XX_SDIV_SHIFT);
+		pll_writel(pll, tmp, PLL35XX_CON0_OFFSET);
+
+		/* wait_lock_time */
+		do {
+			cpu_relax();
+			tmp = pll_readl(pll, PLL35XX_CON0_OFFSET);
+		} while (!(tmp & (PLL35XX_LOCK_STAT_MASK
+				<< PLL35XX_LOCK_STAT_SHIFT)));
+	}
+
+	return 0;
+}
+
 static const struct clk_ops samsung_pll35xx_clk_ops = {
 	.recalc_rate = samsung_pll35xx_recalc_rate,
+	.round_rate = samsung_pll_round_rate,
+	.set_rate = samsung_pll35xx_set_rate,
+};
+
+static const struct clk_ops samsung_pll35xx_clk_min_ops = {
+	.recalc_rate = samsung_pll35xx_recalc_rate,
 };
 
 struct clk * __init samsung_clk_register_pll35xx(const char *name,
@@ -79,11 +176,15 @@ struct clk * __init samsung_clk_register_pll35xx(const char *name,
 	}
 
 	init.name = name;
-	init.ops = &samsung_pll35xx_clk_ops;
 	init.flags = CLK_GET_RATE_NOCACHE;
 	init.parent_names = &pname;
 	init.num_parents = 1;
 
+	if (rate_table && rate_count)
+		init.ops = &samsung_pll35xx_clk_ops;
+	else
+		init.ops = &samsung_pll35xx_clk_min_ops;
+
 	pll->hw.init = &init;
 	pll->base = base;
 	pll->rate_table = rate_table;
-- 
1.7.9.5