[PATCH 09/13] AT91: PIT: (Almost) remove the global variables
Maxime Ripard
maxime.ripard at free-electrons.com
Wed Jun 25 06:06:41 PDT 2014
The timer driver is using some global variables to define some variables it has
to use in most of its functions, like the base address.
Use some container_of calls to have a single dynamic (and local) variable to
hold this content.
The only exception is in the !DT case, where the call chain to
at91sam926x_ioremap_pit and then at91sam926x_pit_init as init_time makes it
hard for the moment to pass the physical address of the timer.
Signed-off-by: Maxime Ripard <maxime.ripard at free-electrons.com>
---
arch/arm/mach-at91/at91sam926x_time.c | 179 ++++++++++++++++++++--------------
1 file changed, 108 insertions(+), 71 deletions(-)
diff --git a/arch/arm/mach-at91/at91sam926x_time.c b/arch/arm/mach-at91/at91sam926x_time.c
index 9678ac391a81..f2c463567beb 100644
--- a/arch/arm/mach-at91/at91sam926x_time.c
+++ b/arch/arm/mach-at91/at91sam926x_time.c
@@ -20,6 +20,7 @@
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
+#include <linux/slab.h>
#include <mach/hardware.h>
@@ -39,19 +40,35 @@
#define PIT_CPIV(x) ((x) & AT91_PIT_CPIV)
#define PIT_PICNT(x) (((x) & AT91_PIT_PICNT) >> 20)
-static u32 pit_cycle; /* write-once */
-static u32 pit_cnt; /* access only w/system irq blocked */
-static void __iomem *pit_base_addr __read_mostly;
-static struct clk *mck;
+struct pit_data {
+ struct clock_event_device clkevt;
+ struct clocksource clksrc;
-static inline unsigned int pit_read(unsigned int reg_offset)
+ void __iomem *base;
+ u32 cycle;
+ u32 cnt;
+ unsigned int irq;
+ struct clk *mck;
+};
+
+static inline struct pit_data *clksrc_to_pit_data(struct clocksource *clksrc)
{
- return __raw_readl(pit_base_addr + reg_offset);
+ return container_of(clksrc, struct pit_data, clksrc);
}
-static inline void pit_write(unsigned int reg_offset, unsigned long value)
+static inline struct pit_data *clkevt_to_pit_data(struct clock_event_device *clkevt)
{
- __raw_writel(value, pit_base_addr + reg_offset);
+ return container_of(clkevt, struct pit_data, clkevt);
+}
+
+static inline unsigned int pit_read(void __iomem *base, unsigned int reg_offset)
+{
+ return __raw_readl(base + reg_offset);
+}
+
+static inline void pit_write(void __iomem *base, unsigned int reg_offset, unsigned long value)
+{
+ __raw_writel(value, base + reg_offset);
}
/*
@@ -60,40 +77,35 @@ static inline void pit_write(unsigned int reg_offset, unsigned long value)
*/
static cycle_t read_pit_clk(struct clocksource *cs)
{
+ struct pit_data *data = clksrc_to_pit_data(cs);
unsigned long flags;
u32 elapsed;
u32 t;
raw_local_irq_save(flags);
- elapsed = pit_cnt;
- t = pit_read(AT91_PIT_PIIR);
+ elapsed = data->cnt;
+ t = pit_read(data->base, AT91_PIT_PIIR);
raw_local_irq_restore(flags);
- elapsed += PIT_PICNT(t) * pit_cycle;
+ elapsed += PIT_PICNT(t) * data->cycle;
elapsed += PIT_CPIV(t);
return elapsed;
}
-static struct clocksource pit_clk = {
- .name = "pit",
- .rating = 175,
- .read = read_pit_clk,
- .flags = CLOCK_SOURCE_IS_CONTINUOUS,
-};
-
-
/*
* Clockevent device: interrupts every 1/HZ (== pit_cycles * MCK/16)
*/
static void
pit_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev)
{
+ struct pit_data *data = clkevt_to_pit_data(dev);
+
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
/* update clocksource counter */
- pit_cnt += pit_cycle * PIT_PICNT(pit_read(AT91_PIT_PIVR));
- pit_write(AT91_PIT_MR, (pit_cycle - 1) | AT91_PIT_PITEN
- | AT91_PIT_PITIEN);
+ data->cnt += data->cycle * PIT_PICNT(pit_read(data->base, AT91_PIT_PIVR));
+ pit_write(data->base, AT91_PIT_MR,
+ (data->cycle - 1) | AT91_PIT_PITEN | AT91_PIT_PITIEN);
break;
case CLOCK_EVT_MODE_ONESHOT:
BUG();
@@ -101,7 +113,8 @@ pit_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev)
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_UNUSED:
/* disable irq, leaving the clocksource active */
- pit_write(AT91_PIT_MR, (pit_cycle - 1) | AT91_PIT_PITEN);
+ pit_write(data->base, AT91_PIT_MR,
+ (data->cycle - 1) | AT91_PIT_PITEN);
break;
case CLOCK_EVT_MODE_RESUME:
break;
@@ -110,44 +123,40 @@ pit_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev)
static void at91sam926x_pit_suspend(struct clock_event_device *cedev)
{
+ struct pit_data *data = clkevt_to_pit_data(cedev);
+
/* Disable timer */
- pit_write(AT91_PIT_MR, 0);
+ pit_write(data->base, AT91_PIT_MR, 0);
}
-static void at91sam926x_pit_reset(void)
+static void at91sam926x_pit_reset(struct pit_data *data)
{
/* Disable timer and irqs */
- pit_write(AT91_PIT_MR, 0);
+ pit_write(data->base, AT91_PIT_MR, 0);
/* Clear any pending interrupts, wait for PIT to stop counting */
- while (PIT_CPIV(pit_read(AT91_PIT_PIVR)) != 0)
+ while (PIT_CPIV(pit_read(data->base, AT91_PIT_PIVR)) != 0)
cpu_relax();
/* Start PIT but don't enable IRQ */
- pit_write(AT91_PIT_MR, (pit_cycle - 1) | AT91_PIT_PITEN);
+ pit_write(data->base, AT91_PIT_MR,
+ (data->cycle - 1) | AT91_PIT_PITEN);
}
static void at91sam926x_pit_resume(struct clock_event_device *cedev)
{
- at91sam926x_pit_reset();
-}
-
-static struct clock_event_device pit_clkevt = {
- .name = "pit",
- .features = CLOCK_EVT_FEAT_PERIODIC,
- .shift = 32,
- .rating = 100,
- .set_mode = pit_clkevt_mode,
- .suspend = at91sam926x_pit_suspend,
- .resume = at91sam926x_pit_resume,
-};
+ struct pit_data *data = clkevt_to_pit_data(cedev);
+ at91sam926x_pit_reset(data);
+}
/*
* IRQ handler for the timer.
*/
static irqreturn_t at91sam926x_pit_interrupt(int irq, void *dev_id)
{
+ struct pit_data *data = dev_id;
+
/*
* irqs should be disabled here, but as the irq is shared they are only
* guaranteed to be off if the timer irq is registered first.
@@ -155,15 +164,15 @@ static irqreturn_t at91sam926x_pit_interrupt(int irq, void *dev_id)
WARN_ON_ONCE(!irqs_disabled());
/* The PIT interrupt may be disabled, and is shared */
- if ((pit_clkevt.mode == CLOCK_EVT_MODE_PERIODIC)
- && (pit_read(AT91_PIT_SR) & AT91_PIT_PITS)) {
+ if ((data->clkevt.mode == CLOCK_EVT_MODE_PERIODIC) &&
+ (pit_read(data->base, AT91_PIT_SR) & AT91_PIT_PITS)) {
unsigned nr_ticks;
/* Get number of ticks performed before irq, and ack it */
- nr_ticks = PIT_PICNT(pit_read(AT91_PIT_PIVR));
+ nr_ticks = PIT_PICNT(pit_read(data->base, AT91_PIT_PIVR));
do {
- pit_cnt += pit_cycle;
- pit_clkevt.event_handler(&pit_clkevt);
+ data->cnt += data->cycle;
+ data->clkevt.event_handler(&data->clkevt);
nr_ticks--;
} while (nr_ticks);
@@ -176,7 +185,7 @@ static irqreturn_t at91sam926x_pit_interrupt(int irq, void *dev_id)
/*
* Set up both clocksource and clockevent support.
*/
-static void __init at91sam926x_pit_common_init(unsigned int pit_irq)
+static void __init at91sam926x_pit_common_init(struct pit_data *data)
{
unsigned long pit_rate;
unsigned bits;
@@ -186,67 +195,95 @@ static void __init at91sam926x_pit_common_init(unsigned int pit_irq)
* Use our actual MCK to figure out how many MCK/16 ticks per
* 1/HZ period (instead of a compile-time constant LATCH).
*/
- pit_rate = clk_get_rate(mck) / 16;
- pit_cycle = (pit_rate + HZ/2) / HZ;
- WARN_ON(((pit_cycle - 1) & ~AT91_PIT_PIV) != 0);
+ pit_rate = clk_get_rate(data->mck) / 16;
+ data->cycle = (pit_rate + HZ/2) / HZ;
+ WARN_ON(((data->cycle - 1) & ~AT91_PIT_PIV) != 0);
/* Initialize and enable the timer */
- at91sam926x_pit_reset();
+ at91sam926x_pit_reset(data);
/*
* Register clocksource. The high order bits of PIV are unused,
* so this isn't a 32-bit counter unless we get clockevent irqs.
*/
- bits = 12 /* PICNT */ + ilog2(pit_cycle) /* PIV */;
- pit_clk.mask = CLOCKSOURCE_MASK(bits);
- clocksource_register_hz(&pit_clk, pit_rate);
+ bits = 12 /* PICNT */ + ilog2(data->cycle) /* PIV */;
+ data->clksrc.mask = CLOCKSOURCE_MASK(bits);
+ data->clksrc.name = "pit";
+ data->clksrc.rating = 175;
+ data->clksrc.read = read_pit_clk,
+ data->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS,
+ clocksource_register_hz(&data->clksrc, pit_rate);
/* Set up irq handler */
- ret = request_irq(pit_irq, at91sam926x_pit_interrupt,
+ ret = request_irq(data->irq, at91sam926x_pit_interrupt,
IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL,
- "at91_tick", pit_base_addr);
+ "at91_tick", data);
if (ret)
panic(pr_fmt("Unable to setup IRQ\n"));
/* Set up and register clockevents */
- pit_clkevt.mult = div_sc(pit_rate, NSEC_PER_SEC, pit_clkevt.shift);
- pit_clkevt.cpumask = cpumask_of(0);
- clockevents_register_device(&pit_clkevt);
+ data->clkevt.name = "pit";
+ data->clkevt.features = CLOCK_EVT_FEAT_PERIODIC;
+ data->clkevt.shift = 32;
+ data->clkevt.mult = div_sc(pit_rate, NSEC_PER_SEC, data->clkevt.shift);
+ data->clkevt.rating = 100;
+ data->clkevt.cpumask = cpumask_of(0);
+
+ data->clkevt.set_mode = pit_clkevt_mode;
+ data->clkevt.resume = at91sam926x_pit_resume;
+ data->clkevt.suspend = at91sam926x_pit_suspend;
+ clockevents_register_device(&data->clkevt);
}
static void __init at91sam926x_pit_dt_init(struct device_node *node)
{
- unsigned int irq;
+ struct pit_data *data;
- pit_base_addr = of_iomap(node, 0);
- if (!pit_base_addr)
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ panic(pr_fmt("Unable to allocate memory\n"));
+
+ data->base = of_iomap(node, 0);
+ if (!data->base)
panic(pr_fmt("Could not map PIT address\n"));
- mck = of_clk_get(node, 0);
- if (IS_ERR(mck))
+ data->mck = of_clk_get(node, 0);
+ if (IS_ERR(data->mck))
/* Fallback on clkdev for !CCF-based boards */
- mck = clk_get(NULL, "mck");
+ data->mck = clk_get(NULL, "mck");
- if (IS_ERR(mck))
+ if (IS_ERR(data->mck))
panic(pr_fmt("Unable to get mck clk\n"));
/* Get the interrupts property */
- irq = irq_of_parse_and_map(node, 0);
- if (!irq)
+ data->irq = irq_of_parse_and_map(node, 0);
+ if (!data->irq)
panic(pr_fmt("Unable to get IRQ from DT\n"));
- at91sam926x_pit_common_init(irq);
+ at91sam926x_pit_common_init(data);
}
CLOCKSOURCE_OF_DECLARE(at91sam926x_pit, "atmel,at91sam9260-pit",
at91sam926x_pit_dt_init);
+static void __iomem *pit_base_addr;
+
void __init at91sam926x_pit_init(void)
{
- mck = clk_get(NULL, "mck");
- if (IS_ERR(mck))
+ struct pit_data *data;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ panic(pr_fmt("Unable to allocate memory\n"));
+
+ data->base = pit_base_addr;
+
+ data->mck = clk_get(NULL, "mck");
+ if (IS_ERR(data->mck))
panic(pr_fmt("Unable to get mck clk\n"));
- at91sam926x_pit_common_init(NR_IRQS_LEGACY + AT91_ID_SYS);
+ data->irq = NR_IRQS_LEGACY + AT91_ID_SYS;
+
+ at91sam926x_pit_common_init(data);
}
void __init at91sam926x_ioremap_pit(u32 addr)
--
2.0.0
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