ARM: tegra: clock: Redo clock locking

Give each clock its own lock, and remove all lock traversals from
parent to child clocks to prevent AB-BA deadlocks.

Signed-off-by: Colin Cross <ccross@android.com>
Change-Id: I0afb7d1bca956439b1a4f17bbc6748aaec706b49

1 files changed, 41 insertions, 34 deletions

diff --git a/arch/arm/mach-tegra/tegra2_clocks.c b/arch/arm/mach-tegra/tegra2_clocks.c
index 7f5ed03fa958..8bc46e7e0988 100644
--- a/arch/arm/mach-tegra/tegra2_clocks.c
+++ b/arch/arm/mach-tegra/tegra2_clocks.c
@@ -23,7 +23,7 @@
 #include <linux/spinlock.h>
 #include <linux/delay.h>
 #include <linux/io.h>
-#include <linux/hrtimer.h>
+#include <linux/clk.h>
 
 #include <asm/clkdev.h>
 
@@ -337,12 +337,12 @@ static int tegra2_super_clk_set_parent(struct clk *c, struct clk *p)
 			val |= sel->value << shift;
 
 			if (c->refcnt)
-				clk_enable_locked(p);
+				clk_enable(p);
 
 			clk_writel(val, c->reg);
 
 			if (c->refcnt && c->parent)
-				clk_disable_locked(c->parent);
+				clk_disable(c->parent);
 
 			clk_reparent(c, p);
 			return 0;
@@ -389,31 +389,31 @@ static int tegra2_cpu_clk_set_rate(struct clk *c, unsigned long rate)
 	 * Take an extra reference to the main pll so it doesn't turn
 	 * off when we move the cpu off of it
 	 */
-	clk_enable_locked(c->u.cpu.main);
+	clk_enable(c->u.cpu.main);
 
-	ret = clk_set_parent_locked(c->parent, c->u.cpu.backup);
+	ret = clk_set_parent(c->parent, c->u.cpu.backup);
 	if (ret) {
 		pr_err("Failed to switch cpu to clock %s\n", c->u.cpu.backup->name);
 		goto out;
 	}
 
-	if (rate == c->u.cpu.backup->rate)
+	if (rate == clk_get_rate(c->u.cpu.backup))
 		goto out;
 
-	ret = clk_set_rate_locked(c->u.cpu.main, rate);
+	ret = clk_set_rate(c->u.cpu.main, rate);
 	if (ret) {
 		pr_err("Failed to change cpu pll to %lu\n", rate);
 		goto out;
 	}
 
-	ret = clk_set_parent_locked(c->parent, c->u.cpu.main);
+	ret = clk_set_parent(c->parent, c->u.cpu.main);
 	if (ret) {
 		pr_err("Failed to switch cpu to clock %s\n", c->u.cpu.main->name);
 		goto out;
 	}
 
 out:
-	clk_disable_locked(c->u.cpu.main);
+	clk_disable(c->u.cpu.main);
 	return ret;
 }
 
@@ -465,7 +465,7 @@ static void tegra2_bus_clk_disable(struct clk *c)
 static int tegra2_bus_clk_set_rate(struct clk *c, unsigned long rate)
 {
 	u32 val = clk_readl(c->reg);
-	unsigned long parent_rate = c->parent->rate;
+	unsigned long parent_rate = clk_get_rate(c->parent);
 	int i;
 	for (i = 1; i <= 4; i++) {
 		if (rate == parent_rate / i) {
@@ -539,14 +539,15 @@ static void tegra2_blink_clk_disable(struct clk *c)
 
 static int tegra2_blink_clk_set_rate(struct clk *c, unsigned long rate)
 {
-	if (rate >= c->parent->rate) {
+	unsigned long parent_rate = clk_get_rate(c->parent);
+	if (rate >= parent_rate) {
 		c->div = 1;
 		pmc_writel(0, c->reg);
 	} else {
 		unsigned int on_off;
 		u32 val;
 
-		on_off = DIV_ROUND_UP(c->parent->rate / 8, rate);
+		on_off = DIV_ROUND_UP(parent_rate / 8, rate);
 		c->div = on_off * 8;
 
 		val = (on_off & PMC_BLINK_TIMER_DATA_ON_MASK) <<
@@ -632,7 +633,7 @@ static int tegra2_pll_clk_set_rate(struct clk *c, unsigned long rate)
 
 	pr_debug("%s: %s %lu\n", __func__, c->name, rate);
 
-	input_rate = c->parent->rate;
+	input_rate = clk_get_rate(c->parent);
 	for (sel = c->u.pll.freq_table; sel->input_rate != 0; sel++) {
 		if (sel->input_rate == input_rate && sel->output_rate == rate) {
 			c->mul = sel->n;
@@ -772,9 +773,11 @@ static int tegra2_pll_div_clk_set_rate(struct clk *c, unsigned long rate)
 	u32 val;
 	u32 new_val;
 	int divider_u71;
+	unsigned long parent_rate = clk_get_rate(c->parent);
+
 	pr_debug("%s: %s %lu\n", __func__, c->name, rate);
 	if (c->flags & DIV_U71) {
-		divider_u71 = clk_div71_get_divider(c->parent->rate, rate);
+		divider_u71 = clk_div71_get_divider(parent_rate, rate);
 		if (divider_u71 >= 0) {
 			val = clk_readl(c->reg);
 			new_val = val >> c->reg_shift;
@@ -792,7 +795,7 @@ static int tegra2_pll_div_clk_set_rate(struct clk *c, unsigned long rate)
 			return 0;
 		}
 	} else if (c->flags & DIV_2) {
-		if (c->parent->rate == rate * 2)
+		if (parent_rate == rate * 2)
 			return 0;
 	}
 	return -EINVAL;
@@ -801,15 +804,16 @@ static int tegra2_pll_div_clk_set_rate(struct clk *c, unsigned long rate)
 static long tegra2_pll_div_clk_round_rate(struct clk *c, unsigned long rate)
 {
 	int divider;
+	unsigned long parent_rate = clk_get_rate(c->parent);
 	pr_debug("%s: %s %lu\n", __func__, c->name, rate);
 
 	if (c->flags & DIV_U71) {
-		divider = clk_div71_get_divider(c->parent->rate, rate);
+		divider = clk_div71_get_divider(parent_rate, rate);
 		if (divider < 0)
 			return divider;
-		return c->parent->rate * 2 / (divider + 2);
+		return parent_rate * 2 / (divider + 2);
 	} else if (c->flags & DIV_2) {
-		return c->parent->rate / 2;
+		return parent_rate / 2;
 	}
 	return -EINVAL;
 }
@@ -923,12 +927,12 @@ static int tegra2_periph_clk_set_parent(struct clk *c, struct clk *p)
 			val |= (sel->value) << PERIPH_CLK_SOURCE_SHIFT;
 
 			if (c->refcnt)
-				clk_enable_locked(p);
+				clk_enable(p);
 
 			clk_writel(val, c->reg);
 
 			if (c->refcnt && c->parent)
-				clk_disable_locked(c->parent);
+				clk_disable(c->parent);
 
 			clk_reparent(c, p);
 			return 0;
@@ -942,9 +946,10 @@ static int tegra2_periph_clk_set_rate(struct clk *c, unsigned long rate)
 {
 	u32 val;
 	int divider;
-	pr_debug("%s: %lu\n", __func__, rate);
+	unsigned long parent_rate = clk_get_rate(c->parent);
+
 	if (c->flags & DIV_U71) {
-		divider = clk_div71_get_divider(c->parent->rate, rate);
+		divider = clk_div71_get_divider(parent_rate, rate);
 		if (divider >= 0) {
 			val = clk_readl(c->reg);
 			val &= ~PERIPH_CLK_SOURCE_DIVU71_MASK;
@@ -955,7 +960,7 @@ static int tegra2_periph_clk_set_rate(struct clk *c, unsigned long rate)
 			return 0;
 		}
 	} else if (c->flags & DIV_U16) {
-		divider = clk_div16_get_divider(c->parent->rate, rate);
+		divider = clk_div16_get_divider(parent_rate, rate);
 		if (divider >= 0) {
 			val = clk_readl(c->reg);
 			val &= ~PERIPH_CLK_SOURCE_DIVU16_MASK;
@@ -965,7 +970,7 @@ static int tegra2_periph_clk_set_rate(struct clk *c, unsigned long rate)
 			c->mul = 1;
 			return 0;
 		}
-	} else if (c->parent->rate <= rate) {
+	} else if (parent_rate <= rate) {
 		c->div = 1;
 		c->mul = 1;
 		return 0;
@@ -977,19 +982,20 @@ static long tegra2_periph_clk_round_rate(struct clk *c,
 	unsigned long rate)
 {
 	int divider;
+	unsigned long parent_rate = clk_get_rate(c->parent);
 	pr_debug("%s: %s %lu\n", __func__, c->name, rate);
 
 	if (c->flags & DIV_U71) {
-		divider = clk_div71_get_divider(c->parent->rate, rate);
+		divider = clk_div71_get_divider(parent_rate, rate);
 		if (divider < 0)
 			return divider;
 
-		return c->parent->rate * 2 / (divider + 2);
+		return parent_rate * 2 / (divider + 2);
 	} else if (c->flags & DIV_U16) {
-		divider = clk_div16_get_divider(c->parent->rate, rate);
+		divider = clk_div16_get_divider(parent_rate, rate);
 		if (divider < 0)
 			return divider;
-		return c->parent->rate / (divider + 1);
+		return parent_rate / (divider + 1);
 	}
 	return -EINVAL;
 }
@@ -1017,7 +1023,7 @@ static void tegra2_clk_double_init(struct clk *c)
 
 static int tegra2_clk_double_set_rate(struct clk *c, unsigned long rate)
 {
-	if (rate != 2 * c->parent->rate)
+	if (rate != 2 * clk_get_rate(c->parent))
 		return -EINVAL;
 	c->mul = 2;
 	c->div = 1;
@@ -1068,12 +1074,12 @@ static int tegra2_audio_sync_clk_set_parent(struct clk *c, struct clk *p)
 			val |= sel->value;
 
 			if (c->refcnt)
-				clk_enable_locked(p);
+				clk_enable(p);
 
 			clk_writel(val, c->reg);
 
 			if (c->refcnt && c->parent)
-				clk_disable_locked(c->parent);
+				clk_disable(c->parent);
 
 			clk_reparent(c, p);
 			return 0;
@@ -1134,12 +1140,13 @@ static void tegra_clk_shared_bus_update(struct clk *bus)
 	struct clk *c;
 	unsigned long rate = bus->u.shared_bus.min_rate;
 
-	list_for_each_entry(c, &bus->u.shared_bus.list, u.shared_bus_user.node)
+	list_for_each_entry(c, &bus->u.shared_bus.list,
+			u.shared_bus_user.node) {
 		if (c->u.shared_bus_user.enabled)
 			rate = max(c->u.shared_bus_user.rate, rate);
+	}
 
-	if (rate != bus->rate)
-		clk_set_rate_locked(bus, rate);
+	clk_set_rate(bus, rate);
 };
 
 static void tegra_clk_shared_bus_init(struct clk *c)