clk: at91: fix programmable clk irq handling

The PCKRDY bit is not set until the system clock is enabled.
This patch moves the management of the ready status in the system clock
driver.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: Jean-Jacques Hiblot <jjhiblot@traphandler.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

drivers/clk/at91/clk-programmable.c

@@ -13,12 +13,9 @@
 #include <linux/clk/at91_pmc.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
-#include <linux/of_irq.h>
 #include <linux/io.h>
 #include <linux/wait.h>
 #include <linux/sched.h>
-#include <linux/interrupt.h>
-#include <linux/irq.h>
 
 #include "pmc.h"
 
@@ -38,68 +35,23 @@ struct clk_programmable_layout {
 struct clk_programmable {
 	struct clk_hw hw;
 	struct at91_pmc *pmc;
-	unsigned int irq;
-	wait_queue_head_t wait;
 	u8 id;
-	u8 css;
-	u8 pres;
-	u8 slckmck;
 	const struct clk_programmable_layout *layout;
 };
 
 #define to_clk_programmable(hw) container_of(hw, struct clk_programmable, hw)
 
-
-static irqreturn_t clk_programmable_irq_handler(int irq, void *dev_id)
-{
-	struct clk_programmable *prog = (struct clk_programmable *)dev_id;
-
-	wake_up(&prog->wait);
-
-	return IRQ_HANDLED;
-}
-
-static int clk_programmable_prepare(struct clk_hw *hw)
-{
-	u32 tmp;
-	struct clk_programmable *prog = to_clk_programmable(hw);
-	struct at91_pmc *pmc = prog->pmc;
-	const struct clk_programmable_layout *layout = prog->layout;
-	u8 id = prog->id;
-	u32 mask = PROG_STATUS_MASK(id);
-
-	tmp = prog->css | (prog->pres << layout->pres_shift);
-	if (layout->have_slck_mck && prog->slckmck)
-		tmp |= AT91_PMC_CSSMCK_MCK;
-
-	pmc_write(pmc, AT91_PMC_PCKR(id), tmp);
-
-	while (!(pmc_read(pmc, AT91_PMC_SR) & mask))
-		wait_event(prog->wait, pmc_read(pmc, AT91_PMC_SR) & mask);
-
-	return 0;
-}
-
-static int clk_programmable_is_ready(struct clk_hw *hw)
-{
-	struct clk_programmable *prog = to_clk_programmable(hw);
-	struct at91_pmc *pmc = prog->pmc;
-
-	return !!(pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_PCKR(prog->id));
-}
-
 static unsigned long clk_programmable_recalc_rate(struct clk_hw *hw,
 						  unsigned long parent_rate)
 {
-	u32 tmp;
+	u32 pres;
 	struct clk_programmable *prog = to_clk_programmable(hw);
 	struct at91_pmc *pmc = prog->pmc;
 	const struct clk_programmable_layout *layout = prog->layout;
 
-	tmp = pmc_read(pmc, AT91_PMC_PCKR(prog->id));
-	prog->pres = (tmp >> layout->pres_shift) & PROG_PRES_MASK;
-
-	return parent_rate >> prog->pres;
+	pres = (pmc_read(pmc, AT91_PMC_PCKR(prog->id)) >> layout->pres_shift) &
+	       PROG_PRES_MASK;
+	return parent_rate >> pres;
 }
 
 static long clk_programmable_determine_rate(struct clk_hw *hw,
@@ -146,17 +98,22 @@ static int clk_programmable_set_parent(struct clk_hw *hw, u8 index)
 {
 	struct clk_programmable *prog = to_clk_programmable(hw);
 	const struct clk_programmable_layout *layout = prog->layout;
+	struct at91_pmc *pmc = prog->pmc;
+	u32 tmp = pmc_read(pmc, AT91_PMC_PCKR(prog->id)) & ~layout->css_mask;
+
+	if (layout->have_slck_mck)
+		tmp &= AT91_PMC_CSSMCK_MCK;
+
 	if (index > layout->css_mask) {
 		if (index > PROG_MAX_RM9200_CSS && layout->have_slck_mck) {
-			prog->css = 0;
-			prog->slckmck = 1;
+			tmp |= AT91_PMC_CSSMCK_MCK;
 			return 0;
 		} else {
 			return -EINVAL;
 		}
 	}
 
-	prog->css = index;
+	pmc_write(pmc, AT91_PMC_PCKR(prog->id), tmp | index);
 	return 0;
 }
 
@@ -169,13 +126,9 @@ static u8 clk_programmable_get_parent(struct clk_hw *hw)
 	const struct clk_programmable_layout *layout = prog->layout;
 
 	tmp = pmc_read(pmc, AT91_PMC_PCKR(prog->id));
-	prog->css = tmp & layout->css_mask;
-	ret = prog->css;
-	if (layout->have_slck_mck) {
-		prog->slckmck = !!(tmp & AT91_PMC_CSSMCK_MCK);
-		if (prog->slckmck && !ret)
-			ret = PROG_MAX_RM9200_CSS + 1;
-	}
+	ret = tmp & layout->css_mask;
+	if (layout->have_slck_mck && (tmp & AT91_PMC_CSSMCK_MCK) && !ret)
+		ret = PROG_MAX_RM9200_CSS + 1;
 
 	return ret;
 }
@@ -184,11 +137,15 @@ static int clk_programmable_set_rate(struct clk_hw *hw, unsigned long rate,
 				     unsigned long parent_rate)
 {
 	struct clk_programmable *prog = to_clk_programmable(hw);
+	struct at91_pmc *pmc = prog->pmc;
+	const struct clk_programmable_layout *layout = prog->layout;
 	unsigned long best_rate = parent_rate;
 	unsigned long best_diff;
 	unsigned long new_diff;
 	unsigned long cur_rate;
 	int shift = 0;
+	u32 tmp = pmc_read(pmc, AT91_PMC_PCKR(prog->id)) &
+		  ~(PROG_PRES_MASK << layout->pres_shift);
 
 	if (rate > parent_rate)
 		return parent_rate;
@@ -196,7 +153,7 @@ static int clk_programmable_set_rate(struct clk_hw *hw, unsigned long rate,
 		best_diff = parent_rate - rate;
 
 	if (!best_diff) {
-		prog->pres = shift;
+		pmc_write(pmc, AT91_PMC_PCKR(prog->id), tmp | shift);
 		return 0;
 	}
 
@@ -220,13 +177,13 @@ static int clk_programmable_set_rate(struct clk_hw *hw, unsigned long rate,
 			break;
 	}
 
-	prog->pres = shift;
+	pmc_write(pmc, AT91_PMC_PCKR(prog->id),
+		  tmp | (shift << layout->pres_shift));
+
 	return 0;
 }
 
 static const struct clk_ops programmable_ops = {
-	.prepare = clk_programmable_prepare,
-	.is_prepared = clk_programmable_is_ready,
 	.recalc_rate = clk_programmable_recalc_rate,
 	.determine_rate = clk_programmable_determine_rate,
 	.get_parent = clk_programmable_get_parent,
@@ -235,16 +192,14 @@ static const struct clk_ops programmable_ops = {
 };
 
 static struct clk * __init
-at91_clk_register_programmable(struct at91_pmc *pmc, unsigned int irq,
+at91_clk_register_programmable(struct at91_pmc *pmc,
 			       const char *name, const char **parent_names,
 			       u8 num_parents, u8 id,
 			       const struct clk_programmable_layout *layout)
 {
-	int ret;
 	struct clk_programmable *prog;
 	struct clk *clk = NULL;
 	struct clk_init_data init;
-	char irq_name[11];
 
 	if (id > PROG_ID_MAX)
 		return ERR_PTR(-EINVAL);
@@ -263,14 +218,6 @@ at91_clk_register_programmable(struct at91_pmc *pmc, unsigned int irq,
 	prog->layout = layout;
 	prog->hw.init = &init;
 	prog->pmc = pmc;
-	prog->irq = irq;
-	init_waitqueue_head(&prog->wait);
-	irq_set_status_flags(prog->irq, IRQ_NOAUTOEN);
-	snprintf(irq_name, sizeof(irq_name), "clk-prog%d", id);
-	ret = request_irq(prog->irq, clk_programmable_irq_handler,
-			  IRQF_TRIGGER_HIGH, irq_name, prog);
-	if (ret)
-		return ERR_PTR(ret);
 
 	clk = clk_register(NULL, &prog->hw);
 	if (IS_ERR(clk))
@@ -304,7 +251,6 @@ of_at91_clk_prog_setup(struct device_node *np, struct at91_pmc *pmc,
 	int num;
 	u32 id;
 	int i;
-	unsigned int irq;
 	struct clk *clk;
 	int num_parents;
 	const char *parent_names[PROG_SOURCE_MAX];
@@ -332,11 +278,7 @@ of_at91_clk_prog_setup(struct device_node *np, struct at91_pmc *pmc,
 		if (of_property_read_string(np, "clock-output-names", &name))
 			name = progclknp->name;
 
-		irq = irq_of_parse_and_map(progclknp, 0);
-		if (!irq)
-			continue;
-
-		clk = at91_clk_register_programmable(pmc, irq, name,
+		clk = at91_clk_register_programmable(pmc, name,
 						     parent_names, num_parents,
 						     id, layout);
 		if (IS_ERR(clk))

drivers/clk/at91/clk-system.c

@@ -14,6 +14,11 @@
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/of_irq.h>
+#include <linux/interrupt.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
 
 #include "pmc.h"
 
@@ -25,19 +30,48 @@
 struct clk_system {
 	struct clk_hw hw;
 	struct at91_pmc *pmc;
+	unsigned int irq;
+	wait_queue_head_t wait;
 	u8 id;
 };
 
-static int clk_system_enable(struct clk_hw *hw)
+static inline int is_pck(int id)
+{
+	return (id >= 8) && (id <= 15);
+}
+static irqreturn_t clk_system_irq_handler(int irq, void *dev_id)
+{
+	struct clk_system *sys = (struct clk_system *)dev_id;
+
+	wake_up(&sys->wait);
+	disable_irq_nosync(sys->irq);
+
+	return IRQ_HANDLED;
+}
+
+static int clk_system_prepare(struct clk_hw *hw)
 {
 	struct clk_system *sys = to_clk_system(hw);
 	struct at91_pmc *pmc = sys->pmc;
+	u32 mask = 1 << sys->id;
 
-	pmc_write(pmc, AT91_PMC_SCER, 1 << sys->id);
+	pmc_write(pmc, AT91_PMC_SCER, mask);
+
+	if (!is_pck(sys->id))
+		return 0;
+
+	while (!(pmc_read(pmc, AT91_PMC_SR) & mask)) {
+		if (sys->irq) {
+			enable_irq(sys->irq);
+			wait_event(sys->wait,
+				   pmc_read(pmc, AT91_PMC_SR) & mask);
+		} else
+			cpu_relax();
+	}
 	return 0;
 }
 
-static void clk_system_disable(struct clk_hw *hw)
+static void clk_system_unprepare(struct clk_hw *hw)
 {
 	struct clk_system *sys = to_clk_system(hw);
 	struct at91_pmc *pmc = sys->pmc;
@@ -45,27 +79,34 @@ static void clk_system_disable(struct clk_hw *hw)
 	pmc_write(pmc, AT91_PMC_SCDR, 1 << sys->id);
 }
 
-static int clk_system_is_enabled(struct clk_hw *hw)
+static int clk_system_is_prepared(struct clk_hw *hw)
 {
 	struct clk_system *sys = to_clk_system(hw);
 	struct at91_pmc *pmc = sys->pmc;
 
-	return !!(pmc_read(pmc, AT91_PMC_SCSR) & (1 << sys->id));
+	if (!(pmc_read(pmc, AT91_PMC_SCSR) & (1 << sys->id)))
+		return 0;
+
+	if (!is_pck(sys->id))
+		return 1;
+
+	return !!(pmc_read(pmc, AT91_PMC_SR) & (1 << sys->id));
 }
 
 static const struct clk_ops system_ops = {
-	.enable = clk_system_enable,
-	.disable = clk_system_disable,
-	.is_enabled = clk_system_is_enabled,
+	.prepare = clk_system_prepare,
+	.unprepare = clk_system_unprepare,
+	.is_prepared = clk_system_is_prepared,
 };
 
 static struct clk * __init
 at91_clk_register_system(struct at91_pmc *pmc, const char *name,
-			 const char *parent_name, u8 id)
+			 const char *parent_name, u8 id, int irq)
 {
 	struct clk_system *sys;
 	struct clk *clk = NULL;
 	struct clk_init_data init;
+	int ret;
 
 	if (!parent_name || id > SYSTEM_MAX_ID)
 		return ERR_PTR(-EINVAL);
@@ -89,6 +130,15 @@ at91_clk_register_system(struct at91_pmc *pmc, const char *name,
 	sys->id = id;
 	sys->hw.init = &init;
 	sys->pmc = pmc;
+	sys->irq = irq;
+	if (irq) {
+		init_waitqueue_head(&sys->wait);
+		irq_set_status_flags(sys->irq, IRQ_NOAUTOEN);
+		ret = request_irq(sys->irq, clk_system_irq_handler,
+				IRQF_TRIGGER_HIGH, name, sys);
+		if (ret)
+			return ERR_PTR(ret);
+	}
 
 	clk = clk_register(NULL, &sys->hw);
 	if (IS_ERR(clk))
@@ -101,6 +151,7 @@ static void __init
 of_at91_clk_sys_setup(struct device_node *np, struct at91_pmc *pmc)
 {
 	int num;
+	int irq = 0;
 	u32 id;
 	struct clk *clk;
 	const char *name;
@@ -118,9 +169,12 @@ of_at91_clk_sys_setup(struct device_node *np, struct at91_pmc *pmc)
 		if (of_property_read_string(np, "clock-output-names", &name))
 			name = sysclknp->name;
 
+		if (is_pck(id))
+			irq = irq_of_parse_and_map(sysclknp, 0);
+
 		parent_name = of_clk_get_parent_name(sysclknp, 0);
 
-		clk = at91_clk_register_system(pmc, name, parent_name, id);
+		clk = at91_clk_register_system(pmc, name, parent_name, id, irq);
 		if (IS_ERR(clk))
 			continue;