2 files changed, 74 insertions, 2 deletions

diff --git a/drivers/clk/meson/clk-pll.c b/drivers/clk/meson/clk-pll.c
index 4adc1e89212c..01341553f50b 100644
--- a/drivers/clk/meson/clk-pll.c
+++ b/drivers/clk/meson/clk-pll.c
@@ -116,6 +116,30 @@ static const struct pll_rate_table *meson_clk_get_pll_settings(struct meson_clk_
 	return NULL;
 }
 
+/* Specific wait loop for GXL/GXM GP0 PLL */
+static int meson_clk_pll_wait_lock_reset(struct meson_clk_pll *pll,
+					 struct parm *p_n)
+{
+	int delay = 100;
+	u32 reg;
+
+	while (delay > 0) {
+		reg = readl(pll->base + p_n->reg_off);
+		writel(reg | MESON_PLL_RESET, pll->base + p_n->reg_off);
+		udelay(10);
+		writel(reg & ~MESON_PLL_RESET, pll->base + p_n->reg_off);
+
+		/* This delay comes from AMLogic tree clk-gp0-gxl driver */
+		mdelay(1);
+
+		reg = readl(pll->base + p_n->reg_off);
+		if (reg & MESON_PLL_LOCK)
+			return 0;
+		delay--;
+	}
+	return -ETIMEDOUT;
+}
+
 static int meson_clk_pll_wait_lock(struct meson_clk_pll *pll,
 				   struct parm *p_n)
 {
@@ -132,6 +156,15 @@ static int meson_clk_pll_wait_lock(struct meson_clk_pll *pll,
 	return -ETIMEDOUT;
 }
 
+static void meson_clk_pll_init_params(struct meson_clk_pll *pll)
+{
+	int i;
+
+	for (i = 0 ; i < pll->params.params_count ; ++i)
+		writel(pll->params.params_table[i].value,
+		       pll->base + pll->params.params_table[i].reg_off);
+}
+
 static int meson_clk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
 				  unsigned long parent_rate)
 {
@@ -151,10 +184,16 @@ static int meson_clk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
 	if (!rate_set)
 		return -EINVAL;
 
+	/* Initialize the PLL in a clean state if specified */
+	if (pll->params.params_count)
+		meson_clk_pll_init_params(pll);
+
 	/* PLL reset */
 	p = &pll->n;
 	reg = readl(pll->base + p->reg_off);
-	writel(reg | MESON_PLL_RESET, pll->base + p->reg_off);
+	/* If no_init_reset is provided, avoid resetting at this point */
+	if (!pll->params.no_init_reset)
+		writel(reg | MESON_PLL_RESET, pll->base + p->reg_off);
 
 	reg = PARM_SET(p->width, p->shift, reg, rate_set->n);
 	writel(reg, pll->base + p->reg_off);
@@ -184,7 +223,17 @@ static int meson_clk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
 	}
 
 	p = &pll->n;
-	ret = meson_clk_pll_wait_lock(pll, p);
+	/* If clear_reset_for_lock is provided, remove the reset bit here */
+	if (pll->params.clear_reset_for_lock) {
+		reg = readl(pll->base + p->reg_off);
+		writel(reg & ~MESON_PLL_RESET, pll->base + p->reg_off);
+	}
+
+	/* If reset_lock_loop, use a special loop including resetting */
+	if (pll->params.reset_lock_loop)
+		ret = meson_clk_pll_wait_lock_reset(pll, p);
+	else
+		ret = meson_clk_pll_wait_lock(pll, p);
 	if (ret) {
 		pr_warn("%s: pll did not lock, trying to restore old rate %lu\n",
 			__func__, old_rate);
diff --git a/drivers/clk/meson/clkc.h b/drivers/clk/meson/clkc.h
index ad254675edd8..b0c9999d03de 100644
--- a/drivers/clk/meson/clkc.h
+++ b/drivers/clk/meson/clkc.h
@@ -62,6 +62,28 @@ struct pll_rate_table {
 		.frac		= (_frac),				\
 	}								\
 
+struct pll_params_table {
+	unsigned int reg_off;
+	unsigned int value;
+};
+
+#define PLL_PARAM(_reg, _val)						\
+	{								\
+		.reg_off	= (_reg),				\
+		.value		= (_val),				\
+	}
+
+struct pll_setup_params {
+	struct pll_params_table *params_table;
+	unsigned int params_count;
+	/* Workaround for GP0, do not reset before configuring */
+	bool no_init_reset;
+	/* Workaround for GP0, unreset right before checking for lock */
+	bool clear_reset_for_lock;
+	/* Workaround for GXL GP0, reset in the lock checking loop */
+	bool reset_lock_loop;
+};
+
 struct meson_clk_pll {
 	struct clk_hw hw;
 	void __iomem *base;
@@ -70,6 +92,7 @@ struct meson_clk_pll {
 	struct parm frac;
 	struct parm od;
 	struct parm od2;
+	const struct pll_setup_params params;
 	const struct pll_rate_table *rate_table;
 	unsigned int rate_count;
 	spinlock_t *lock;