ARM: at91: PIT: (Almost) remove the global variables
authorMaxime Ripard <maxime.ripard@free-electrons.com>
Tue, 1 Jul 2014 09:33:23 +0000 (11:33 +0200)
committerNicolas Ferre <nicolas.ferre@atmel.com>
Wed, 3 Sep 2014 08:55:44 +0000 (10:55 +0200)
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@free-electrons.com>
Acked-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
arch/arm/mach-at91/at91sam926x_time.c

index e476474cb05e1d16fb51b7169c83ce3b27760225..9abb289dce72996afd9e3402278589971868dd74 100644 (file)
@@ -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>
 
 #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 = DIV_ROUND_CLOSEST(pit_rate, HZ);
-       WARN_ON(((pit_cycle - 1) & ~AT91_PIT_PIV) != 0);
+       pit_rate = clk_get_rate(data->mck) / 16;
+       data->cycle = DIV_ROUND_CLOSEST(pit_rate, 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)