[PATCH 1/8] clk: sunxi: factors: Add m_start parameters

[Maxime Ripard]

Some clocks start incrementing the m factor at 0. Add a parameter to handle
it just like we did for the N factor.

Since the behaviour until now was to assume that the m factor was starting
at 1, we also need to fix the other users.

Signed-off-by: Maxime Ripard <maxime.ripard at free-electrons.com>
---
 drivers/clk/sunxi/clk-factors.c    | 11 ++++++++++-
 drivers/clk/sunxi/clk-factors.h    |  2 ++
 drivers/clk/sunxi/clk-mod0.c       |  2 ++
 drivers/clk/sunxi/clk-sun8i-mbus.c |  2 ++
 drivers/clk/sunxi/clk-sun9i-core.c |  6 ++++++
 drivers/clk/sunxi/clk-sunxi.c      | 10 ++++++++++
 6 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/sunxi/clk-factors.c b/drivers/clk/sunxi/clk-factors.c
index 8c20190a3e9f..100a711c3e3d 100644
--- a/drivers/clk/sunxi/clk-factors.c
+++ b/drivers/clk/sunxi/clk-factors.c
@@ -56,15 +56,24 @@ static unsigned long clk_factors_recalc_rate(struct clk_hw *hw,
 	/* Get each individual factor if applicable */
 	if (config->nwidth != SUNXI_FACTORS_NOT_APPLICABLE)
 		n = FACTOR_GET(config->nshift, config->nwidth, reg);
+
 	if (config->kwidth != SUNXI_FACTORS_NOT_APPLICABLE)
 		k = FACTOR_GET(config->kshift, config->kwidth, reg);
+
 	if (config->mwidth != SUNXI_FACTORS_NOT_APPLICABLE)
 		m = FACTOR_GET(config->mshift, config->mwidth, reg);
+	else
+		/* Make sure we don't get a division by zero */
+		m = 1;
+
 	if (config->pwidth != SUNXI_FACTORS_NOT_APPLICABLE)
 		p = FACTOR_GET(config->pshift, config->pwidth, reg);
 
 	/* Calculate the rate */
-	rate = (parent_rate * (n + config->n_start) * (k + 1) >> p) / (m + 1);
+	rate = parent_rate * (n + config->n_start);
+	rate *= k + 1;
+	rate >>= p;
+	rate /= m + config->m_start;
 
 	return rate;
 }
diff --git a/drivers/clk/sunxi/clk-factors.h b/drivers/clk/sunxi/clk-factors.h
index 171085ab5513..735d756d2923 100644
--- a/drivers/clk/sunxi/clk-factors.h
+++ b/drivers/clk/sunxi/clk-factors.h
@@ -16,6 +16,8 @@ struct clk_factors_config {
 	u8 mwidth;
 	u8 pshift;
 	u8 pwidth;
+
+	u8 m_start;
 	u8 n_start;
 };
 
diff --git a/drivers/clk/sunxi/clk-mod0.c b/drivers/clk/sunxi/clk-mod0.c
index ec8f5a1fca09..eefa9be4078b 100644
--- a/drivers/clk/sunxi/clk-mod0.c
+++ b/drivers/clk/sunxi/clk-mod0.c
@@ -66,6 +66,8 @@ static struct clk_factors_config sun4i_a10_mod0_config = {
 	.mwidth = 4,
 	.pshift = 16,
 	.pwidth = 2,
+
+	.m_start = 1,
 };
 
 static const struct factors_data sun4i_a10_mod0_data = {
diff --git a/drivers/clk/sunxi/clk-sun8i-mbus.c b/drivers/clk/sunxi/clk-sun8i-mbus.c
index 14cd026064bf..66fbf14a0f8a 100644
--- a/drivers/clk/sunxi/clk-sun8i-mbus.c
+++ b/drivers/clk/sunxi/clk-sun8i-mbus.c
@@ -55,6 +55,8 @@ static void sun8i_a23_get_mbus_factors(u32 *freq, u32 parent_rate,
 static struct clk_factors_config sun8i_a23_mbus_config = {
 	.mshift = 0,
 	.mwidth = 3,
+
+	.m_start = 1,
 };
 
 static const struct factors_data sun8i_a23_mbus_data __initconst = {
diff --git a/drivers/clk/sunxi/clk-sun9i-core.c b/drivers/clk/sunxi/clk-sun9i-core.c
index d8da77d72861..97e87ca4a8fc 100644
--- a/drivers/clk/sunxi/clk-sun9i-core.c
+++ b/drivers/clk/sunxi/clk-sun9i-core.c
@@ -78,6 +78,8 @@ static struct clk_factors_config sun9i_a80_pll4_config = {
 	.nwidth = 8,
 	.pshift = 16,
 	.pwidth = 1,
+
+	.m_start = 1,
 };
 
 static const struct factors_data sun9i_a80_pll4_data __initconst = {
@@ -137,6 +139,8 @@ static void sun9i_a80_get_gt_factors(u32 *freq, u32 parent_rate,
 static struct clk_factors_config sun9i_a80_gt_config = {
 	.mshift = 0,
 	.mwidth = 2,
+
+	.m_start = 1,
 };
 
 static const struct factors_data sun9i_a80_gt_data __initconst = {
@@ -294,6 +298,8 @@ static struct clk_factors_config sun9i_a80_apb1_config = {
 	.mwidth = 5,
 	.pshift = 16,
 	.pwidth = 2,
+
+	.m_start = 1,
 };
 
 static const struct factors_data sun9i_a80_apb1_data __initconst = {
diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
index 7e1e2bd189b6..6df869050986 100644
--- a/drivers/clk/sunxi/clk-sunxi.c
+++ b/drivers/clk/sunxi/clk-sunxi.c
@@ -616,6 +616,8 @@ static struct clk_factors_config sun4i_pll1_config = {
 	.mwidth = 2,
 	.pshift = 16,
 	.pwidth = 2,
+
+	.m_start = 1,
 };
 
 static struct clk_factors_config sun6i_a31_pll1_config = {
@@ -625,6 +627,8 @@ static struct clk_factors_config sun6i_a31_pll1_config = {
 	.kwidth = 2,
 	.mshift = 0,
 	.mwidth = 2,
+
+	.m_start = 1,
 	.n_start = 1,
 };
 
@@ -637,6 +641,8 @@ static struct clk_factors_config sun8i_a23_pll1_config = {
 	.mwidth = 2,
 	.pshift = 16,
 	.pwidth = 2,
+
+	.m_start = 1,
 	.n_start = 1,
 };
 
@@ -665,6 +671,8 @@ static struct clk_factors_config sun4i_apb1_config = {
 	.mwidth = 5,
 	.pshift = 16,
 	.pwidth = 2,
+
+	.m_start = 1,
 };
 
 /* user manual says "n" but it's really "p" */
@@ -673,6 +681,8 @@ static struct clk_factors_config sun7i_a20_out_config = {
 	.mwidth = 5,
 	.pshift = 20,
 	.pwidth = 2,
+
+	.m_start = 1,
 };
 
 static const struct factors_data sun4i_pll1_data __initconst = {
-- 
2.3.6