clk: meson: mpll: add rw operation

This patch adds new callbacks to the meson-mpll driver to control
and set the pll rate. For this, we also need to add the enable bit and
sdm enable bit. The corresponding parameters are added to mpll data
structure.

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20170309104154.28295-6-jbrunet@baylibre.com

1 files changed, 147 insertions, 5 deletions

diff --git a/drivers/clk/meson/clk-mpll.c b/drivers/clk/meson/clk-mpll.c
index 03af79005ddb..342b85d4e22a 100644
--- a/drivers/clk/meson/clk-mpll.c
+++ b/drivers/clk/meson/clk-mpll.c
@@ -64,16 +64,50 @@
 #include <linux/clk-provider.h>
 #include "clkc.h"
 
-#define SDM_MAX 16384
+#define SDM_DEN 16384
+#define SDM_MIN 1
+#define SDM_MAX 16383
+#define N2_MIN	4
+#define N2_MAX	127
 
 #define to_meson_clk_mpll(_hw) container_of(_hw, struct meson_clk_mpll, hw)
 
+static unsigned long rate_from_params(unsigned long parent_rate,
+				      unsigned long sdm,
+				      unsigned long n2)
+{
+	return (parent_rate * SDM_DEN) / ((SDM_DEN * n2) + sdm);
+}
+
+static void params_from_rate(unsigned long requested_rate,
+			     unsigned long parent_rate,
+			     unsigned long *sdm,
+			     unsigned long *n2)
+{
+	uint64_t div = parent_rate;
+	unsigned long rem = do_div(div, requested_rate);
+
+	if (div < N2_MIN) {
+		*n2 = N2_MIN;
+		*sdm = SDM_MIN;
+	} else if (div > N2_MAX) {
+		*n2 = N2_MAX;
+		*sdm = SDM_MAX;
+	} else {
+		*n2 = div;
+		*sdm = DIV_ROUND_UP(rem * SDM_DEN, requested_rate);
+		if (*sdm < SDM_MIN)
+			*sdm = SDM_MIN;
+		else if (*sdm > SDM_MAX)
+			*sdm = SDM_MAX;
+	}
+}
+
 static unsigned long mpll_recalc_rate(struct clk_hw *hw,
 		unsigned long parent_rate)
 {
 	struct meson_clk_mpll *mpll = to_meson_clk_mpll(hw);
 	struct parm *p;
-	unsigned long rate = 0;
 	unsigned long reg, sdm, n2;
 
 	p = &mpll->sdm;
@@ -84,11 +118,119 @@ static unsigned long mpll_recalc_rate(struct clk_hw *hw,
 	reg = readl(mpll->base + p->reg_off);
 	n2 = PARM_GET(p->width, p->shift, reg);
 
-	rate = (parent_rate * SDM_MAX) / ((SDM_MAX * n2) + sdm);
+	return rate_from_params(parent_rate, sdm, n2);
+}
+
+static long mpll_round_rate(struct clk_hw *hw,
+			    unsigned long rate,
+			    unsigned long *parent_rate)
+{
+	unsigned long sdm, n2;
+
+	params_from_rate(rate, *parent_rate, &sdm, &n2);
+	return rate_from_params(*parent_rate, sdm, n2);
+}
+
+static int mpll_set_rate(struct clk_hw *hw,
+			 unsigned long rate,
+			 unsigned long parent_rate)
+{
+	struct meson_clk_mpll *mpll = to_meson_clk_mpll(hw);
+	struct parm *p;
+	unsigned long reg, sdm, n2;
+	unsigned long flags = 0;
+
+	params_from_rate(rate, parent_rate, &sdm, &n2);
+
+	if (mpll->lock)
+		spin_lock_irqsave(mpll->lock, flags);
+	else
+		__acquire(mpll->lock);
+
+	p = &mpll->sdm;
+	reg = readl(mpll->base + p->reg_off);
+	reg = PARM_SET(p->width, p->shift, reg, sdm);
+	writel(reg, mpll->base + p->reg_off);
+
+	p = &mpll->sdm_en;
+	reg = readl(mpll->base + p->reg_off);
+	reg = PARM_SET(p->width, p->shift, reg, 1);
+	writel(reg, mpll->base + p->reg_off);
+
+	p = &mpll->n2;
+	reg = readl(mpll->base + p->reg_off);
+	reg = PARM_SET(p->width, p->shift, reg, n2);
+	writel(reg, mpll->base + p->reg_off);
+
+	if (mpll->lock)
+		spin_unlock_irqrestore(mpll->lock, flags);
+	else
+		__release(mpll->lock);
 
-	return rate;
+	return 0;
+}
+
+static void mpll_enable_core(struct clk_hw *hw, int enable)
+{
+	struct meson_clk_mpll *mpll = to_meson_clk_mpll(hw);
+	struct parm *p;
+	unsigned long reg;
+	unsigned long flags = 0;
+
+	if (mpll->lock)
+		spin_lock_irqsave(mpll->lock, flags);
+	else
+		__acquire(mpll->lock);
+
+	p = &mpll->en;
+	reg = readl(mpll->base + p->reg_off);
+	reg = PARM_SET(p->width, p->shift, reg, enable ? 1 : 0);
+	writel(reg, mpll->base + p->reg_off);
+
+	if (mpll->lock)
+		spin_unlock_irqrestore(mpll->lock, flags);
+	else
+		__release(mpll->lock);
+}
+
+
+static int mpll_enable(struct clk_hw *hw)
+{
+	mpll_enable_core(hw, 1);
+
+	return 0;
+}
+
+static void mpll_disable(struct clk_hw *hw)
+{
+	mpll_enable_core(hw, 0);
+}
+
+static int mpll_is_enabled(struct clk_hw *hw)
+{
+	struct meson_clk_mpll *mpll = to_meson_clk_mpll(hw);
+	struct parm *p;
+	unsigned long reg;
+	int en;
+
+	p = &mpll->en;
+	reg = readl(mpll->base + p->reg_off);
+	en = PARM_GET(p->width, p->shift, reg);
+
+	return en;
 }
 
 const struct clk_ops meson_clk_mpll_ro_ops = {
-	.recalc_rate = mpll_recalc_rate,
+	.recalc_rate	= mpll_recalc_rate,
+	.round_rate	= mpll_round_rate,
+	.is_enabled	= mpll_is_enabled,
+};
+
+const struct clk_ops meson_clk_mpll_ops = {
+	.recalc_rate	= mpll_recalc_rate,
+	.round_rate	= mpll_round_rate,
+	.set_rate	= mpll_set_rate,
+	.enable		= mpll_enable,
+	.disable	= mpll_disable,
+	.is_enabled	= mpll_is_enabled,
 };