clk: sunxi-ng: Implement factors offsets

The factors we've seen so far all had an offset of one. However, on the
earlier Allwinner SoCs, some factors could have no offset at all, meaning
that the value computed to reach the rate we want to use was the one we had
to program in the registers.

Implement an additional field for the factors that can have such an offset
(linears, not based on a power of two) to specify that offset.

This offset is not linked to the extremums that can be specified in those
structures too. The minimum and maximum are representing the range of
values we can use to try to compute the best rate. The offset comes later
on when we want to set the best value in the registers.

Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

drivers/clk/sunxi-ng/ccu_div.h

@@ -41,6 +41,7 @@ struct ccu_div_internal {
 	u8			width;
 
 	u32			max;
+	u32			offset;
 
 	u32			flags;
 
@@ -58,20 +59,27 @@ struct ccu_div_internal {
 #define _SUNXI_CCU_DIV_TABLE(_shift, _width, _table)			\
 	_SUNXI_CCU_DIV_TABLE_FLAGS(_shift, _width, _table, 0)
 
-#define _SUNXI_CCU_DIV_MAX_FLAGS(_shift, _width, _max, _flags) \
+#define _SUNXI_CCU_DIV_OFFSET_MAX_FLAGS(_shift, _width, _off, _max, _flags) \
 	{								\
 		.shift	= _shift,					\
 		.width	= _width,					\
 		.flags	= _flags,					\
 		.max	= _max,						\
+		.offset	= _off,						\
 	}
 
+#define _SUNXI_CCU_DIV_MAX_FLAGS(_shift, _width, _max, _flags)		\
+	_SUNXI_CCU_DIV_OFFSET_MAX_FLAGS(_shift, _width, 1, _max, _flags)
+
 #define _SUNXI_CCU_DIV_FLAGS(_shift, _width, _flags)			\
 	_SUNXI_CCU_DIV_MAX_FLAGS(_shift, _width, 0, _flags)
 
 #define _SUNXI_CCU_DIV_MAX(_shift, _width, _max)			\
 	_SUNXI_CCU_DIV_MAX_FLAGS(_shift, _width, _max, 0)
 
+#define _SUNXI_CCU_DIV_OFFSET(_shift, _width, _offset)			\
+	_SUNXI_CCU_DIV_OFFSET_MAX_FLAGS(_shift, _width, _offset, 0, 0)
+
 #define _SUNXI_CCU_DIV(_shift, _width)					\
 	_SUNXI_CCU_DIV_FLAGS(_shift, _width, 0)
 

drivers/clk/sunxi-ng/ccu_mp.c

@@ -89,11 +89,14 @@ static unsigned long ccu_mp_recalc_rate(struct clk_hw *hw,
 
 	m = reg >> cmp->m.shift;
 	m &= (1 << cmp->m.width) - 1;
+	m += cmp->m.offset;
+	if (!m)
+		m++;
 
 	p = reg >> cmp->p.shift;
 	p &= (1 << cmp->p.width) - 1;
 
-	return (parent_rate >> p) / (m + 1);
+	return (parent_rate >> p) / m;
 }
 
 static int ccu_mp_determine_rate(struct clk_hw *hw,
@@ -124,9 +127,10 @@ static int ccu_mp_set_rate(struct clk_hw *hw, unsigned long rate,
 	reg = readl(cmp->common.base + cmp->common.reg);
 	reg &= ~GENMASK(cmp->m.width + cmp->m.shift - 1, cmp->m.shift);
 	reg &= ~GENMASK(cmp->p.width + cmp->p.shift - 1, cmp->p.shift);
+	reg |= (m - cmp->m.offset) << cmp->m.shift;
+	reg |= ilog2(p) << cmp->p.shift;
 
-	writel(reg | (ilog2(p) << cmp->p.shift) | ((m - 1) << cmp->m.shift),
-	       cmp->common.base + cmp->common.reg);
+	writel(reg, cmp->common.base + cmp->common.reg);
 
 	spin_unlock_irqrestore(cmp->common.lock, flags);
 

drivers/clk/sunxi-ng/ccu_mult.c

@@ -85,7 +85,7 @@ static unsigned long ccu_mult_recalc_rate(struct clk_hw *hw,
 	ccu_mux_helper_adjust_parent_for_prediv(&cm->common, &cm->mux, -1,
 						&parent_rate);
 
-	return parent_rate * (val + 1);
+	return parent_rate * (val + cm->mult.offset);
 }
 
 static int ccu_mult_determine_rate(struct clk_hw *hw,
@@ -121,9 +121,9 @@ static int ccu_mult_set_rate(struct clk_hw *hw, unsigned long rate,
 
 	reg = readl(cm->common.base + cm->common.reg);
 	reg &= ~GENMASK(cm->mult.width + cm->mult.shift - 1, cm->mult.shift);
+	reg |= ((_cm.mult - cm->mult.offset) << cm->mult.shift);
 
-	writel(reg | ((_cm.mult - 1) << cm->mult.shift),
-	       cm->common.base + cm->common.reg);
+	writel(reg, cm->common.base + cm->common.reg);
 
 	spin_unlock_irqrestore(cm->common.lock, flags);
 

drivers/clk/sunxi-ng/ccu_mult.h

@@ -6,20 +6,28 @@
 #include "ccu_mux.h"
 
 struct ccu_mult_internal {
+	u8	offset;
 	u8	shift;
 	u8	width;
 	u8	min;
 };
 
-#define _SUNXI_CCU_MULT_MIN(_shift, _width, _min)	\
-	{						\
-		.shift	= _shift,			\
-		.width	= _width,			\
-		.min	= _min,				\
+#define _SUNXI_CCU_MULT_OFFSET_MIN(_shift, _width, _offset, _min)	\
+	{								\
+		.min	= _min,						\
+		.offset	= _offset,					\
+		.shift	= _shift,					\
+		.width	= _width,					\
 	}
 
+#define _SUNXI_CCU_MULT_MIN(_shift, _width, _min)	\
+	_SUNXI_CCU_MULT_OFFSET_MIN(_shift, _width, 1, _min)
+
+#define _SUNXI_CCU_MULT_OFFSET(_shift, _width, _offset)	\
+	_SUNXI_CCU_MULT_OFFSET_MIN(_shift, _width, _offset, 1)
+
 #define _SUNXI_CCU_MULT(_shift, _width)		\
-	_SUNXI_CCU_MULT_MIN(_shift, _width, 1)
+	_SUNXI_CCU_MULT_OFFSET_MIN(_shift, _width, 1, 1)
 
 struct ccu_mult {
 	u32			enable;

drivers/clk/sunxi-ng/ccu_nk.c

@@ -76,12 +76,17 @@ static unsigned long ccu_nk_recalc_rate(struct clk_hw *hw,
 
 	n = reg >> nk->n.shift;
 	n &= (1 << nk->n.width) - 1;
+	n += nk->n.offset;
+	if (!n)
+		n++;
 
 	k = reg >> nk->k.shift;
 	k &= (1 << nk->k.width) - 1;
+	k += nk->k.offset;
+	if (!k)
+		k++;
 
-	rate = parent_rate * (n + 1) * (k + 1);
-
+	rate = parent_rate * n * k;
 	if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
 		rate /= nk->fixed_post_div;
 
@@ -135,8 +140,9 @@ static int ccu_nk_set_rate(struct clk_hw *hw, unsigned long rate,
 	reg &= ~GENMASK(nk->n.width + nk->n.shift - 1, nk->n.shift);
 	reg &= ~GENMASK(nk->k.width + nk->k.shift - 1, nk->k.shift);
 
-	writel(reg | ((_nk.k - 1) << nk->k.shift) | ((_nk.n - 1) << nk->n.shift),
-	       nk->common.base + nk->common.reg);
+	reg |= (_nk.k - nk->k.offset) << nk->k.shift;
+	reg |= (_nk.n - nk->n.offset) << nk->n.shift;
+	writel(reg, nk->common.base + nk->common.reg);
 
 	spin_unlock_irqrestore(nk->common.lock, flags);
 

drivers/clk/sunxi-ng/ccu_nkm.c

@@ -82,14 +82,23 @@ static unsigned long ccu_nkm_recalc_rate(struct clk_hw *hw,
 
 	n = reg >> nkm->n.shift;
 	n &= (1 << nkm->n.width) - 1;
+	n += nkm->n.offset;
+	if (!n)
+		n++;
 
 	k = reg >> nkm->k.shift;
 	k &= (1 << nkm->k.width) - 1;
+	k += nkm->k.offset;
+	if (!k)
+		k++;
 
 	m = reg >> nkm->m.shift;
 	m &= (1 << nkm->m.width) - 1;
+	m += nkm->m.offset;
+	if (!m)
+		m++;
 
-	return parent_rate * (n + 1) * (k + 1) / (m + 1);
+	return parent_rate * n  * k / m;
 }
 
 static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux,
@@ -145,10 +154,9 @@ static int ccu_nkm_set_rate(struct clk_hw *hw, unsigned long rate,
 	reg &= ~GENMASK(nkm->k.width + nkm->k.shift - 1, nkm->k.shift);
 	reg &= ~GENMASK(nkm->m.width + nkm->m.shift - 1, nkm->m.shift);
 
-	reg |= (_nkm.n - 1) << nkm->n.shift;
-	reg |= (_nkm.k - 1) << nkm->k.shift;
-	reg |= (_nkm.m - 1) << nkm->m.shift;
-
+	reg |= (_nkm.n - nkm->n.offset) << nkm->n.shift;
+	reg |= (_nkm.k - nkm->k.offset) << nkm->k.shift;
+	reg |= (_nkm.m - nkm->m.offset) << nkm->m.shift;
 	writel(reg, nkm->common.base + nkm->common.reg);
 
 	spin_unlock_irqrestore(nkm->common.lock, flags);

drivers/clk/sunxi-ng/ccu_nkmp.c

@@ -88,17 +88,26 @@ static unsigned long ccu_nkmp_recalc_rate(struct clk_hw *hw,
 
 	n = reg >> nkmp->n.shift;
 	n &= (1 << nkmp->n.width) - 1;
+	n += nkmp->n.offset;
+	if (!n)
+		n++;
 
 	k = reg >> nkmp->k.shift;
 	k &= (1 << nkmp->k.width) - 1;
+	k += nkmp->k.offset;
+	if (!k)
+		k++;
 
 	m = reg >> nkmp->m.shift;
 	m &= (1 << nkmp->m.width) - 1;
+	m += nkmp->m.offset;
+	if (!m)
+		m++;
 
 	p = reg >> nkmp->p.shift;
 	p &= (1 << nkmp->p.width) - 1;
 
-	return (parent_rate * (n + 1) * (k + 1) >> p) / (m + 1);
+	return parent_rate * n * k >> p / m;
 }
 
 static long ccu_nkmp_round_rate(struct clk_hw *hw, unsigned long rate,
@@ -148,9 +157,9 @@ static int ccu_nkmp_set_rate(struct clk_hw *hw, unsigned long rate,
 	reg &= ~GENMASK(nkmp->m.width + nkmp->m.shift - 1, nkmp->m.shift);
 	reg &= ~GENMASK(nkmp->p.width + nkmp->p.shift - 1, nkmp->p.shift);
 
-	reg |= (_nkmp.n - 1) << nkmp->n.shift;
-	reg |= (_nkmp.k - 1) << nkmp->k.shift;
-	reg |= (_nkmp.m - 1) << nkmp->m.shift;
+	reg |= (_nkmp.n - nkmp->n.offset) << nkmp->n.shift;
+	reg |= (_nkmp.k - nkmp->k.offset) << nkmp->k.shift;
+	reg |= (_nkmp.m - nkmp->m.offset) << nkmp->m.shift;
 	reg |= ilog2(_nkmp.p) << nkmp->p.shift;
 
 	writel(reg, nkmp->common.base + nkmp->common.reg);

drivers/clk/sunxi-ng/ccu_nm.c

@@ -80,11 +80,17 @@ static unsigned long ccu_nm_recalc_rate(struct clk_hw *hw,
 
 	n = reg >> nm->n.shift;
 	n &= (1 << nm->n.width) - 1;
+	n += nm->n.offset;
+	if (!n)
+		n++;
 
 	m = reg >> nm->m.shift;
 	m &= (1 << nm->m.width) - 1;
+	m += nm->m.offset;
+	if (!m)
+		m++;
 
-	return parent_rate * (n + 1) / (m + 1);
+	return parent_rate * n / m;
 }
 
 static long ccu_nm_round_rate(struct clk_hw *hw, unsigned long rate,
@@ -129,8 +135,9 @@ static int ccu_nm_set_rate(struct clk_hw *hw, unsigned long rate,
 	reg &= ~GENMASK(nm->n.width + nm->n.shift - 1, nm->n.shift);
 	reg &= ~GENMASK(nm->m.width + nm->m.shift - 1, nm->m.shift);
 
-	writel(reg | ((_nm.m - 1) << nm->m.shift) | ((_nm.n - 1) << nm->n.shift),
-	       nm->common.base + nm->common.reg);
+	reg |= (_nm.n - nm->n.offset) << nm->n.shift;
+	reg |= (_nm.m - nm->m.offset) << nm->m.shift;
+	writel(reg, nm->common.base + nm->common.reg);
 
 	spin_unlock_irqrestore(nm->common.lock, flags);