[v2,2/4] drivers: clk: st: PLL rate change implementation for DVFS

diff --git a/drivers/clk/st/clkgen-mux.c b/drivers/clk/st/clkgen-mux.c
index 4f7f6c0..5dc5ce2 100644
--- a/drivers/clk/st/clkgen-mux.c
+++ b/drivers/clk/st/clkgen-mux.c
@@ -17,6 +17,7 @@ 
 #include <linux/of_address.h>
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
+#include "clkgen.h"
 
 static DEFINE_SPINLOCK(clkgena_divmux_lock);
 static DEFINE_SPINLOCK(clkgenf_lock);
@@ -576,6 +577,7 @@  static struct clkgen_mux_data stih415_a9_mux_data = {
 	.offset = 0,
 	.shift = 1,
 	.width = 2,
+	.lock = &clkgen_a9_lock,
 };
 static struct clkgen_mux_data stih416_a9_mux_data = {
 	.offset = 0,
@@ -586,6 +588,7 @@  static struct clkgen_mux_data stih407_a9_mux_data = {
 	.offset = 0x1a4,
 	.shift = 0,
 	.width = 2,
+	.lock = &clkgen_a9_lock,
 };
 
 static const struct of_device_id mux_of_match[] = {
diff --git a/drivers/clk/st/clkgen-pll.c b/drivers/clk/st/clkgen-pll.c
index 7ee485d..94e5a0b 100644
--- a/drivers/clk/st/clkgen-pll.c
+++ b/drivers/clk/st/clkgen-pll.c
@@ -23,6 +23,7 @@ 
 #include "clkgen.h"
 
 static DEFINE_SPINLOCK(clkgena_c32_odf_lock);
+DEFINE_SPINLOCK(clkgen_a9_lock);
 
 /*
  * Common PLL configuration register bits for PLL800 and PLL1600 C65
@@ -39,6 +40,7 @@  static DEFINE_SPINLOCK(clkgena_c32_odf_lock);
 #define C32_IDF_MASK (0x7)
 #define C32_ODF_MASK (0x3f)
 #define C32_LDF_MASK (0x7f)
+#define C32_CP_MASK (0x1f)
 
 #define C32_MAX_ODFS (4)
 
@@ -51,15 +53,20 @@  struct clkgen_pll_data {
 	struct clkgen_field pdiv;
 	struct clkgen_field idf;
 	struct clkgen_field ldf;
+	struct clkgen_field cp;
 	unsigned int num_odfs;
 	struct clkgen_field odf[C32_MAX_ODFS];
 	struct clkgen_field odf_gate[C32_MAX_ODFS];
+	bool switch2pll_en;
+	struct clkgen_field switch2pll;
+	spinlock_t *lock;
 	const struct clk_ops *ops;
 };
 
 static const struct clk_ops st_pll1600c65_ops;
 static const struct clk_ops st_pll800c65_ops;
 static const struct clk_ops stm_pll3200c32_ops;
+static const struct clk_ops stm_pll3200c32_a9_ops;
 static const struct clk_ops st_pll1200c32_ops;
 
 static const struct clkgen_pll_data st_pll1600c65_ax = {
@@ -242,7 +249,11 @@  static const struct clkgen_pll_data st_pll3200c32_407_a9 = {
 	.num_odfs = 1,
 	.odf		= { CLKGEN_FIELD(0x1b0, C32_ODF_MASK,		8) },
 	.odf_gate	= { CLKGEN_FIELD(0x1ac, 0x1,			28) },
-	.ops		= &stm_pll3200c32_ops,
+	.switch2pll_en	= true,
+	.cp		= CLKGEN_FIELD(0x1a8,	C32_CP_MASK,		1),
+	.switch2pll	= CLKGEN_FIELD(0x1a4,	0x1,			1),
+	.lock = &clkgen_a9_lock,
+	.ops		= &stm_pll3200c32_a9_ops,
 };
 
 /**
@@ -268,10 +279,26 @@  struct clkgen_pll {
 	struct clk_hw		hw;
 	struct clkgen_pll_data	*data;
 	void __iomem		*regs_base;
+	spinlock_t	*lock;
+
+	u32 ndiv;
+	u32 idf;
+	u32 odf;
+	u32 cp;
 };
 
 #define to_clkgen_pll(_hw) container_of(_hw, struct clkgen_pll, hw)
 
+struct stm_pll {
+	unsigned long mdiv;
+	unsigned long ndiv;
+	unsigned long pdiv;
+	unsigned long odf;
+	unsigned long idf;
+	unsigned long ldf;
+	unsigned long cp;
+};
+
 static int clkgen_pll_is_locked(struct clk_hw *hw)
 {
 	struct clkgen_pll *pll = to_clkgen_pll(hw);
@@ -303,8 +330,12 @@  static int __clkgen_pll_enable(struct clk_hw *hw)
 	ret = readl_relaxed_poll_timeout(base + field->offset, reg,
 			!!((reg >> field->shift) & field->mask),  0, 10000);
 
-	if (!ret)
+	if (!ret) {
+		if (pll->data->switch2pll_en)
+			CLKGEN_WRITE(pll, switch2pll, 0);
+
 		pr_debug("%s:%s enabled\n", __clk_get_name(hw->clk), __func__);
+	}
 
 	return ret;
 }
@@ -333,6 +364,9 @@  static void __clkgen_pll_disable(struct clk_hw *hw)
 	if (!clkgen_pll_is_enabled(hw))
 		return;
 
+	if (pll->data->switch2pll_en)
+		CLKGEN_WRITE(pll, switch2pll, 1);
+
 	CLKGEN_WRITE(pll, pdn_ctrl, 1);
 
 	pr_debug("%s:%s disabled\n", __clk_get_name(hw->clk), __func__);
@@ -403,6 +437,67 @@  static unsigned long recalc_stm_pll1600c65(struct clk_hw *hw,
 	return rate;
 }
 
+static int clk_pll3200c32_get_params(unsigned long input, unsigned long output,
+			  struct stm_pll *pll)
+{
+	unsigned long i, n;
+	unsigned long deviation = ~0;
+	unsigned long new_freq;
+	long new_deviation;
+	/* Charge pump table: highest ndiv value for cp=6 to 25 */
+	static const unsigned char cp_table[] = {
+		48, 56, 64, 72, 80, 88, 96, 104, 112, 120,
+		128, 136, 144, 152, 160, 168, 176, 184, 192
+	};
+
+	/* Output clock range: 800Mhz to 1600Mhz */
+	if (output < 800000000 || output > 1600000000)
+		return -EINVAL;
+
+	input /= 1000;
+	output /= 1000;
+
+	for (i = 1; i <= 7 && deviation; i++) {
+		n = i * output / (2 * input);
+
+		/* Checks */
+		if (n < 8)
+			continue;
+		if (n > 200)
+			break;
+
+		new_freq = (input * 2 * n) / i;
+
+		new_deviation = abs(new_freq - output);
+
+		if (!new_deviation || new_deviation < deviation) {
+			pll->idf  = i;
+			pll->ndiv = n;
+			deviation = new_deviation;
+		}
+	}
+
+	if (deviation == ~0) /* No solution found */
+		return -EINVAL;
+
+	/* Computing recommended charge pump value */
+	for (pll->cp = 6; pll->ndiv > cp_table[pll->cp-6]; (pll->cp)++)
+		;
+
+	return 0;
+}
+
+static int clk_pll3200c32_get_rate(unsigned long input, struct stm_pll *pll,
+			unsigned long *rate)
+{
+	if (!pll->idf)
+		pll->idf = 1;
+
+	*rate = ((2 * (input / 1000) * pll->ndiv) / pll->idf) * 1000;
+
+	return 0;
+}
+
 static unsigned long recalc_stm_pll3200c32(struct clk_hw *hw,
 		unsigned long parent_rate)
 {
@@ -425,6 +520,70 @@  static unsigned long recalc_stm_pll3200c32(struct clk_hw *hw,
 	return rate;
 }
 
+static long round_rate_stm_pll3200c32(struct clk_hw *hw, unsigned long rate,
+		unsigned long *prate)
+{
+	struct stm_pll params;
+
+	if (!clk_pll3200c32_get_params(*prate, rate, &params))
+		clk_pll3200c32_get_rate(*prate, &params, &rate);
+	else {
+		pr_debug("%s: %s rate %ld Invalid\n", __func__,
+			 __clk_get_name(hw->clk), rate);
+		return 0;
+	}
+
+	pr_debug("%s: %s new rate %ld [ndiv=%u] [idf=%u]\n",
+		 __func__, __clk_get_name(hw->clk),
+		 rate, (unsigned int)params.ndiv,
+		 (unsigned int)params.idf);
+
+	return rate;
+}
+
+static int set_rate_stm_pll3200c32(struct clk_hw *hw, unsigned long rate,
+				unsigned long parent_rate)
+{
+	struct clkgen_pll *pll = to_clkgen_pll(hw);
+	struct stm_pll params;
+	long hwrate = 0;
+	unsigned long flags = 0;
+
+	if (!rate || !parent_rate)
+		return -EINVAL;
+
+	if (!clk_pll3200c32_get_params(parent_rate, rate, &params))
+		clk_pll3200c32_get_rate(parent_rate, &params, &hwrate);
+
+	pr_debug("%s: %s new rate %ld [ndiv=0x%x] [idf=0x%x]\n",
+		 __func__, __clk_get_name(hw->clk),
+		 hwrate, (unsigned int)params.ndiv,
+		 (unsigned int)params.idf);
+
+	if (!hwrate)
+		return -EINVAL;
+
+	pll->ndiv = params.ndiv;
+	pll->idf = params.idf;
+	pll->cp = params.cp;
+
+	clkgen_pll_disable(hw);
+
+	if (pll->lock)
+		spin_lock_irqsave(pll->lock, flags);
+
+	CLKGEN_WRITE(pll, ndiv, pll->ndiv);
+	CLKGEN_WRITE(pll, idf, pll->idf);
+	CLKGEN_WRITE(pll, cp, pll->cp);
+
+	if (pll->lock)
+		spin_unlock_irqrestore(pll->lock, flags);
+
+	clkgen_pll_enable(hw);
+
+	return 0;
+}
+
 static unsigned long recalc_stm_pll1200c32(struct clk_hw *hw,
 		unsigned long parent_rate)
 {
@@ -473,6 +632,15 @@  static const struct clk_ops stm_pll3200c32_ops = {
 	.recalc_rate	= recalc_stm_pll3200c32,
 };
 
+static const struct clk_ops stm_pll3200c32_a9_ops = {
+	.enable		= clkgen_pll_enable,
+	.disable	= clkgen_pll_disable,
+	.is_enabled	= clkgen_pll_is_enabled,
+	.recalc_rate	= recalc_stm_pll3200c32,
+	.round_rate	= round_rate_stm_pll3200c32,
+	.set_rate	= set_rate_stm_pll3200c32,
+};
+
 static const struct clk_ops st_pll1200c32_ops = {
 	.enable		= clkgen_pll_enable,
 	.disable	= clkgen_pll_disable,
@@ -483,7 +651,7 @@  static const struct clk_ops st_pll1200c32_ops = {
 static struct clk * __init clkgen_pll_register(const char *parent_name,
 				struct clkgen_pll_data	*pll_data,
 				void __iomem *reg,
-				const char *clk_name)
+				const char *clk_name, spinlock_t *lock)
 {
 	struct clkgen_pll *pll;
 	struct clk *clk;
@@ -590,7 +758,7 @@  static void __init clkgena_c65_pll_setup(struct device_node *np)
 	 */
 	clk_data->clks[0] = clkgen_pll_register(parent_name,
 			(struct clkgen_pll_data *) &st_pll1600c65_ax,
-			reg + CLKGENAx_PLL0_OFFSET, clk_name);
+			reg + CLKGENAx_PLL0_OFFSET, clk_name, NULL);
 
 	if (IS_ERR(clk_data->clks[0]))
 		goto err;
@@ -619,7 +787,7 @@  static void __init clkgena_c65_pll_setup(struct device_node *np)
 	 */
 	clk_data->clks[2] = clkgen_pll_register(parent_name,
 			(struct clkgen_pll_data *) &st_pll800c65_ax,
-			reg + CLKGENAx_PLL1_OFFSET, clk_name);
+			reg + CLKGENAx_PLL1_OFFSET, clk_name, NULL);
 
 	if (IS_ERR(clk_data->clks[2]))
 		goto err;
@@ -646,7 +814,7 @@  static struct clk * __init clkgen_odf_register(const char *parent_name,
 	struct clk_gate *gate;
 	struct clk_divider *div;
 
-	flags = CLK_GET_RATE_NOCACHE | CLK_SET_RATE_GATE;
+	flags = CLK_GET_RATE_NOCACHE | CLK_SET_RATE_PARENT;
 
 	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
 	if (!gate)
@@ -754,7 +922,8 @@  static void __init clkgen_c32_pll_setup(struct device_node *np)
 	if (!pll_base)
 		return;
 
-	clk = clkgen_pll_register(parent_name, data, pll_base, np->name);
+	clk = clkgen_pll_register(parent_name, data, pll_base, np->name,
+				  data->lock);
 	if (IS_ERR(clk))
 		return;
 
@@ -843,7 +1012,7 @@  static void __init clkgengpu_c32_pll_setup(struct device_node *np)
 	/*
 	 * PLL 1200MHz output
 	 */
-	clk = clkgen_pll_register(parent_name, data, reg, clk_name);
+	clk = clkgen_pll_register(parent_name, data, reg, clk_name, data->lock);
 
 	if (!IS_ERR(clk))
 		of_clk_add_provider(np, of_clk_src_simple_get, clk);
diff --git a/drivers/clk/st/clkgen.h b/drivers/clk/st/clkgen.h
index 35c8632..f7ec2d9 100644
--- a/drivers/clk/st/clkgen.h
+++ b/drivers/clk/st/clkgen.h
@@ -9,6 +9,8 @@  Copyright (C) 2014 STMicroelectronics
 #ifndef __CLKGEN_INFO_H
 #define __CLKGEN_INFO_H
 
+extern spinlock_t clkgen_a9_lock;
+
 struct clkgen_field {
 	unsigned int offset;
 	unsigned int mask;