[PATCH v2 3/4] clk: at91: fix programmable clk irq handling

From: Jean-Jacques Hiblot
Date: Wed Feb 05 2014 - 03:41:43 EST


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@xxxxxxxxxxx>
Signed-off-by: Jean-Jacques Hiblot <jjhiblot@xxxxxxxxxxxxxxx>
---
drivers/clk/at91/clk-programmable.c | 108 +++++++++---------------------------
drivers/clk/at91/clk-system.c | 74 ++++++++++++++++++++----
2 files changed, 89 insertions(+), 93 deletions(-)

diff --git a/drivers/clk/at91/clk-programmable.c b/drivers/clk/at91/clk-programmable.c
index eff7016..7bcc725 100644
--- a/drivers/clk/at91/clk-programmable.c
+++ b/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))
diff --git a/drivers/clk/at91/clk-system.c b/drivers/clk/at91/clk-system.c
index a98557b..82c5f44 100644
--- a/drivers/clk/at91/clk-system.c
+++ b/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);
@@ -90,6 +131,15 @@ 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))
@@ -102,6 +152,7 @@ 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;
@@ -119,9 +170,12 @@ 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;

--
1.8.5.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/