[PATCH v2] clk: sunxi: predivider handling for factors clock

[Vishnu Patekar <vishnupatekar0510@gmail.com>]

For A31 ahb1 and a83t ahb1 clocks have predivider for certain parent.
To handle this, this patch adds predivider table with parent index,
prediv shift and width, parents with predivider will have nonzero width.

Rate adjustment is moved from clock specific recalc function to generic
factors recalc. Also, adds prediv table for a31.

Signed-off-by: Vishnu Patekar <vishnupatekar0510@gmail.com>
---
 drivers/clk/sunxi/clk-factors.c | 31 +++++++++++++++----------------
 drivers/clk/sunxi/clk-factors.h | 10 +++++++++-
 drivers/clk/sunxi/clk-sunxi.c   | 31 +++++++++----------------------
 3 files changed, 33 insertions(+), 39 deletions(-)

diff --git a/drivers/clk/sunxi/clk-factors.c b/drivers/clk/sunxi/clk-factors.c
index ddefe96..8f3b637 100644
--- a/drivers/clk/sunxi/clk-factors.c
+++ b/drivers/clk/sunxi/clk-factors.c
@@ -45,10 +45,12 @@ static unsigned long clk_factors_recalc_rate(struct clk_hw *hw,
 					     unsigned long parent_rate)
 {
 	u8 n = 1, k = 0, p = 0, m = 0;
+	u8 par_index = 0;
 	u32 reg;
 	unsigned long rate;
 	struct clk_factors *factors = to_clk_factors(hw);
 	const struct clk_factors_config *config = factors->config;
+	const struct clk_factors_prediv *prediv = factors->prediv_config;
 
 	/* Fetch the register value */
 	reg = readl(factors->reg);
@@ -63,24 +65,16 @@ static unsigned long clk_factors_recalc_rate(struct clk_hw *hw,
 	if (config->pwidth != SUNXI_FACTORS_NOT_APPLICABLE)
 		p = FACTOR_GET(config->pshift, config->pwidth, reg);
 
-	if (factors->recalc) {
-		struct factors_request factors_req = {
-			.parent_rate = parent_rate,
-			.n = n,
-			.k = k,
-			.m = m,
-			.p = p,
-		};
-
+	if (prediv) {
 		/* get mux details from mux clk structure */
 		if (factors->mux)
-			factors_req.parent_index =
-				(reg >> factors->mux->shift) &
-				factors->mux->mask;
-
-		factors->recalc(&factors_req);
+			par_index = (reg >> factors->mux->shift) &
+					factors->mux->mask;
 
-		return factors_req.rate;
+		if (prediv[par_index].width != SUNXI_FACTORS_NOT_APPLICABLE) {
+			m = FACTOR_GET(prediv[par_index].shift,
+				prediv[par_index].width, reg);
+		}
 	}
 
 	/* Calculate the rate */
@@ -102,8 +96,12 @@ static int clk_factors_determine_rate(struct clk_hw *hw,
 	for (i = 0; i < num_parents; i++) {
 		struct factors_request factors_req = {
 			.rate = req->rate,
-			.parent_index = i,
 		};
+
+		if (factors->prediv_config)
+			factors_req.prediv_width =
+						factors->prediv_config[i].width;
+
 		parent = clk_hw_get_parent_by_index(hw, i);
 		if (!parent)
 			continue;
@@ -211,6 +209,7 @@ struct clk *sunxi_factors_register(struct device_node *node,
 	/* set up factors properties */
 	factors->reg = reg;
 	factors->config = data->table;
+	factors->prediv_config = data->prediv_table;
 	factors->get_factors = data->getter;
 	factors->recalc = data->recalc;
 	factors->lock = lock;
diff --git a/drivers/clk/sunxi/clk-factors.h b/drivers/clk/sunxi/clk-factors.h
index 1e63c5b..b1b7745 100644
--- a/drivers/clk/sunxi/clk-factors.h
+++ b/drivers/clk/sunxi/clk-factors.h
@@ -18,10 +18,16 @@ struct clk_factors_config {
 	u8 n_start;
 };
 
+struct clk_factors_prediv {
+	u8 parent_index;
+	u8 shift;
+	u8 width;
+};
+
 struct factors_request {
 	unsigned long rate;
 	unsigned long parent_rate;
-	u8 parent_index;
+	u8 prediv_width;
 	u8 n;
 	u8 k;
 	u8 m;
@@ -33,6 +39,7 @@ struct factors_data {
 	int mux;
 	int muxmask;
 	const struct clk_factors_config *table;
+	const struct clk_factors_prediv *prediv_table;
 	void (*getter)(struct factors_request *req);
 	void (*recalc)(struct factors_request *req);
 	const char *name;
@@ -42,6 +49,7 @@ struct clk_factors {
 	struct clk_hw hw;
 	void __iomem *reg;
 	const struct clk_factors_config *config;
+	const struct clk_factors_prediv *prediv_config;
 	void (*get_factors)(struct factors_request *req);
 	void (*recalc)(struct factors_request *req);
 	spinlock_t *lock;
diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
index 91de0a0..5a5f26b 100644
--- a/drivers/clk/sunxi/clk-sunxi.c
+++ b/drivers/clk/sunxi/clk-sunxi.c
@@ -282,8 +282,6 @@ static void sun5i_a13_get_ahb_factors(struct factors_request *req)
 	req->p = div;
 }
 
-#define SUN6I_AHB1_PARENT_PLL6	3
-
 /**
  * sun6i_a31_get_ahb_factors() - calculates m, p factors for AHB
  * AHB rate is calculated as follows
@@ -307,7 +305,7 @@ static void sun6i_get_ahb1_factors(struct factors_request *req)
 	div = DIV_ROUND_UP(req->parent_rate, req->rate);
 
 	/* calculate pre-divider if parent is pll6 */
-	if (req->parent_index == SUN6I_AHB1_PARENT_PLL6) {
+	if (req->prediv_width) {
 		if (div < 4)
 			calcp = 0;
 		else if (div / 2 < 4)
@@ -329,22 +327,6 @@ static void sun6i_get_ahb1_factors(struct factors_request *req)
 }
 
 /**
- * sun6i_ahb1_recalc() - calculates AHB clock rate from m, p factors and
- *			 parent index
- */
-static void sun6i_ahb1_recalc(struct factors_request *req)
-{
-	req->rate = req->parent_rate;
-
-	/* apply pre-divider first if parent is pll6 */
-	if (req->parent_index == SUN6I_AHB1_PARENT_PLL6)
-		req->rate /= req->m + 1;
-
-	/* clk divider */
-	req->rate >>= req->p;
-}
-
-/**
  * sun4i_get_apb1_factors() - calculates m, p factors for APB1
  * APB1 rate is calculated as follows
  * rate = (parent_rate >> p) / (m + 1);
@@ -474,12 +456,17 @@ static const struct clk_factors_config sun5i_a13_ahb_config = {
 };
 
 static const struct clk_factors_config sun6i_ahb1_config = {
-	.mshift = 6,
-	.mwidth = 2,
 	.pshift = 4,
 	.pwidth = 2,
 };
 
+static const struct clk_factors_prediv sun6i_ahb1_prediv[] = {
+	{.parent_index = 0, .shift = 0, .width = 0 },	/* LOSC  */
+	{.parent_index = 1, .shift = 0, .width = 0 },	/* OSC24MHz */
+	{.parent_index = 2, .shift = 0, .width = 0 },	/* AXI */
+	{.parent_index = 3, .shift = 6, .width = 2 }	/* PLL6/Pre_div */
+};
+
 static const struct clk_factors_config sun4i_apb1_config = {
 	.mshift = 0,
 	.mwidth = 5,
@@ -551,8 +538,8 @@ static const struct factors_data sun6i_ahb1_data __initconst = {
 	.mux = 12,
 	.muxmask = BIT(1) | BIT(0),
 	.table = &sun6i_ahb1_config,
+	.prediv_table = sun6i_ahb1_prediv,
 	.getter = sun6i_get_ahb1_factors,
-	.recalc = sun6i_ahb1_recalc,
 };
 
 static const struct factors_data sun4i_apb1_data __initconst = {
-- 
1.9.1