clocksource/drivers/fttmr010: Use state container

This converts the Faraday FTTMR010 to use the state container
design pattern. Take some care to handle the state container
and free:ing of resources as has been done in the Moxa driver.

Cc: Joel Stanley <joel@jms.id.au>
Tested-by: Jonas Jensen <jonas.jensen@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

1 files changed, 116 insertions, 74 deletions

diff --git a/drivers/clocksource/timer-fttmr010.c b/drivers/clocksource/timer-fttmr010.c
index db097db346e3..9ad31489bbef 100644
--- a/drivers/clocksource/timer-fttmr010.c
+++ b/drivers/clocksource/timer-fttmr010.c
@@ -15,6 +15,7 @@
 #include <linux/clocksource.h>
 #include <linux/sched_clock.h>
 #include <linux/clk.h>
+#include <linux/slab.h>
 
 /*
  * Register definitions for the timers
@@ -62,23 +63,35 @@
 #define TIMER_3_INT_OVERFLOW    (1 << 8)
 #define TIMER_INT_ALL_MASK      0x1ff
 
-static unsigned int tick_rate;
-static void __iomem *base;
+struct fttmr010 {
+        void __iomem *base;
+        unsigned int tick_rate;
+        struct clock_event_device clkevt;
+};
+
+/* A local singleton used by sched_clock, which is stateless */
+static struct fttmr010 *local_fttmr;
+
+static inline struct fttmr010 *to_fttmr010(struct clock_event_device *evt)
+{
+        return container_of(evt, struct fttmr010, clkevt);
+}
 
 static u64 notrace fttmr010_read_sched_clock(void)
 {
-        return readl(base + TIMER3_COUNT);
+        return readl(local_fttmr->base + TIMER3_COUNT);
 }
 
 static int fttmr010_timer_set_next_event(unsigned long cycles,
                                        struct clock_event_device *evt)
 {
+        struct fttmr010 *fttmr010 = to_fttmr010(evt);
         u32 cr;
 
         /* Setup the match register */
-        cr = readl(base + TIMER1_COUNT);
-        writel(cr + cycles, base + TIMER1_MATCH1);
-        if (readl(base + TIMER1_COUNT) - cr > cycles)
+        cr = readl(fttmr010->base + TIMER1_COUNT);
+        writel(cr + cycles, fttmr010->base + TIMER1_MATCH1);
+        if (readl(fttmr010->base + TIMER1_COUNT) - cr > cycles)
                 return -ETIME;
 
         return 0;
@@ -86,99 +99,90 @@ static int fttmr010_timer_set_next_event(unsigned long cycles,
 
 static int fttmr010_timer_shutdown(struct clock_event_device *evt)
 {
+        struct fttmr010 *fttmr010 = to_fttmr010(evt);
+        u32 cr;
+
+        /* Stop timer and interrupt. */
+        cr = readl(fttmr010->base + TIMER_CR);
+        cr &= ~(TIMER_1_CR_ENABLE | TIMER_1_CR_INT);
+        writel(cr, fttmr010->base + TIMER_CR);
+
+        return 0;
+}
+
+static int fttmr010_timer_set_oneshot(struct clock_event_device *evt)
+{
+        struct fttmr010 *fttmr010 = to_fttmr010(evt);
         u32 cr;
 
-        /*
-         * Disable also for oneshot: the set_next() call will arm the timer
-         * instead.
-         */
         /* Stop timer and interrupt. */
-        cr = readl(base + TIMER_CR);
+        cr = readl(fttmr010->base + TIMER_CR);
         cr &= ~(TIMER_1_CR_ENABLE | TIMER_1_CR_INT);
-        writel(cr, base + TIMER_CR);
+        writel(cr, fttmr010->base + TIMER_CR);
 
         /* Setup counter start from 0 */
-        writel(0, base + TIMER1_COUNT);
-        writel(0, base + TIMER1_LOAD);
+        writel(0, fttmr010->base + TIMER1_COUNT);
+        writel(0, fttmr010->base + TIMER1_LOAD);
 
-        /* enable interrupt */
-        cr = readl(base + TIMER_INTR_MASK);
+        /* Enable interrupt */
+        cr = readl(fttmr010->base + TIMER_INTR_MASK);
         cr &= ~(TIMER_1_INT_OVERFLOW | TIMER_1_INT_MATCH2);
         cr |= TIMER_1_INT_MATCH1;
-        writel(cr, base + TIMER_INTR_MASK);
+        writel(cr, fttmr010->base + TIMER_INTR_MASK);
 
-        /* start the timer */
-        cr = readl(base + TIMER_CR);
+        /* Start the timer */
+        cr = readl(fttmr010->base + TIMER_CR);
         cr |= TIMER_1_CR_ENABLE;
-        writel(cr, base + TIMER_CR);
+        writel(cr, fttmr010->base + TIMER_CR);
 
         return 0;
 }
 
 static int fttmr010_timer_set_periodic(struct clock_event_device *evt)
 {
-        u32 period = DIV_ROUND_CLOSEST(tick_rate, HZ);
+        struct fttmr010 *fttmr010 = to_fttmr010(evt);
+        u32 period = DIV_ROUND_CLOSEST(fttmr010->tick_rate, HZ);
         u32 cr;
 
         /* Stop timer and interrupt */
-        cr = readl(base + TIMER_CR);
+        cr = readl(fttmr010->base + TIMER_CR);
         cr &= ~(TIMER_1_CR_ENABLE | TIMER_1_CR_INT);
-        writel(cr, base + TIMER_CR);
+        writel(cr, fttmr010->base + TIMER_CR);
 
         /* Setup timer to fire at 1/HT intervals. */
         cr = 0xffffffff - (period - 1);
-        writel(cr, base + TIMER1_COUNT);
-        writel(cr, base + TIMER1_LOAD);
+        writel(cr, fttmr010->base + TIMER1_COUNT);
+        writel(cr, fttmr010->base + TIMER1_LOAD);
 
         /* enable interrupt on overflow */
-        cr = readl(base + TIMER_INTR_MASK);
+        cr = readl(fttmr010->base + TIMER_INTR_MASK);
         cr &= ~(TIMER_1_INT_MATCH1 | TIMER_1_INT_MATCH2);
         cr |= TIMER_1_INT_OVERFLOW;
-        writel(cr, base + TIMER_INTR_MASK);
+        writel(cr, fttmr010->base + TIMER_INTR_MASK);
 
         /* Start the timer */
-        cr = readl(base + TIMER_CR);
+        cr = readl(fttmr010->base + TIMER_CR);
         cr |= TIMER_1_CR_ENABLE;
         cr |= TIMER_1_CR_INT;
-        writel(cr, base + TIMER_CR);
+        writel(cr, fttmr010->base + TIMER_CR);
 
         return 0;
 }
 
-/* Use TIMER1 as clock event */
-static struct clock_event_device fttmr010_clockevent = {
-        .name                   = "TIMER1",
-        /* Reasonably fast and accurate clock event */
-        .rating                 = 300,
-        .shift                  = 32,
-        .features               = CLOCK_EVT_FEAT_PERIODIC |
-                                  CLOCK_EVT_FEAT_ONESHOT,
-        .set_next_event         = fttmr010_timer_set_next_event,
-        .set_state_shutdown     = fttmr010_timer_shutdown,
-        .set_state_periodic     = fttmr010_timer_set_periodic,
-        .set_state_oneshot      = fttmr010_timer_shutdown,
-        .tick_resume            = fttmr010_timer_shutdown,
-};
-
 /*
  * IRQ handler for the timer
  */
 static irqreturn_t fttmr010_timer_interrupt(int irq, void *dev_id)
 {
-        struct clock_event_device *evt = &fttmr010_clockevent;
+        struct clock_event_device *evt = dev_id;
 
         evt->event_handler(evt);
         return IRQ_HANDLED;
 }
 
-static struct irqaction fttmr010_timer_irq = {
-        .name           = "Faraday FTTMR010 Timer Tick",
-        .flags          = IRQF_TIMER,
-        .handler        = fttmr010_timer_interrupt,
-};
-
 static int __init fttmr010_timer_init(struct device_node *np)
 {
+        struct fttmr010 *fttmr010;
         int irq;
         struct clk *clk;
         int ret;
@@ -198,53 +202,91 @@ static int __init fttmr010_timer_init(struct device_node *np)
                 pr_err("failed to enable PCLK\n");
                 return ret;
         }
-        tick_rate = clk_get_rate(clk);
 
-        base = of_iomap(np, 0);
-        if (!base) {
+        fttmr010 = kzalloc(sizeof(*fttmr010), GFP_KERNEL);
+        if (!fttmr010) {
+                ret = -ENOMEM;
+                goto out_disable_clock;
+        }
+        fttmr010->tick_rate = clk_get_rate(clk);
+
+        fttmr010->base = of_iomap(np, 0);
+        if (!fttmr010->base) {
                 pr_err("Can't remap registers");
-                return -ENXIO;
+                ret = -ENXIO;
+                goto out_free;
         }
         /* IRQ for timer 1 */
         irq = irq_of_parse_and_map(np, 0);
         if (irq <= 0) {
                 pr_err("Can't parse IRQ");
-                return -EINVAL;
+                ret = -EINVAL;
+                goto out_unmap;
         }
 
         /*
          * Reset the interrupt mask and status
          */
-        writel(TIMER_INT_ALL_MASK, base + TIMER_INTR_MASK);
-        writel(0, base + TIMER_INTR_STATE);
-        writel(TIMER_DEFAULT_FLAGS, base + TIMER_CR);
+        writel(TIMER_INT_ALL_MASK, fttmr010->base + TIMER_INTR_MASK);
+        writel(0, fttmr010->base + TIMER_INTR_STATE);
+        writel(TIMER_DEFAULT_FLAGS, fttmr010->base + TIMER_CR);
 
         /*
          * Setup free-running clocksource timer (interrupts
          * disabled.)
          */
-        writel(0, base + TIMER3_COUNT);
-        writel(0, base + TIMER3_LOAD);
-        writel(0, base + TIMER3_MATCH1);
-        writel(0, base + TIMER3_MATCH2);
-        clocksource_mmio_init(base + TIMER3_COUNT,
-                              "fttmr010_clocksource", tick_rate,
+        local_fttmr = fttmr010;
+        writel(0, fttmr010->base + TIMER3_COUNT);
+        writel(0, fttmr010->base + TIMER3_LOAD);
+        writel(0, fttmr010->base + TIMER3_MATCH1);
+        writel(0, fttmr010->base + TIMER3_MATCH2);
+        clocksource_mmio_init(fttmr010->base + TIMER3_COUNT,
+                              "FTTMR010-TIMER3",
+                              fttmr010->tick_rate,
                               300, 32, clocksource_mmio_readl_up);
-        sched_clock_register(fttmr010_read_sched_clock, 32, tick_rate);
+        sched_clock_register(fttmr010_read_sched_clock, 32,
+                             fttmr010->tick_rate);
 
         /*
-         * Setup clockevent timer (interrupt-driven.)
+         * Setup clockevent timer (interrupt-driven) on timer 1.
          */
-        writel(0, base + TIMER1_COUNT);
-        writel(0, base + TIMER1_LOAD);
-        writel(0, base + TIMER1_MATCH1);
-        writel(0, base + TIMER1_MATCH2);
-        setup_irq(irq, &fttmr010_timer_irq);
-        fttmr010_clockevent.cpumask = cpumask_of(0);
-        clockevents_config_and_register(&fttmr010_clockevent, tick_rate,
+        writel(0, fttmr010->base + TIMER1_COUNT);
+        writel(0, fttmr010->base + TIMER1_LOAD);
+        writel(0, fttmr010->base + TIMER1_MATCH1);
+        writel(0, fttmr010->base + TIMER1_MATCH2);
+        ret = request_irq(irq, fttmr010_timer_interrupt, IRQF_TIMER,
+                          "FTTMR010-TIMER1", &fttmr010->clkevt);
+        if (ret) {
+                pr_err("FTTMR010-TIMER1 no IRQ\n");
+                goto out_unmap;
+        }
+
+        fttmr010->clkevt.name = "FTTMR010-TIMER1";
+        /* Reasonably fast and accurate clock event */
+        fttmr010->clkevt.rating = 300;
+        fttmr010->clkevt.features = CLOCK_EVT_FEAT_PERIODIC |
+                CLOCK_EVT_FEAT_ONESHOT;
+        fttmr010->clkevt.set_next_event = fttmr010_timer_set_next_event;
+        fttmr010->clkevt.set_state_shutdown = fttmr010_timer_shutdown;
+        fttmr010->clkevt.set_state_periodic = fttmr010_timer_set_periodic;
+        fttmr010->clkevt.set_state_oneshot = fttmr010_timer_set_oneshot;
+        fttmr010->clkevt.tick_resume = fttmr010_timer_shutdown;
+        fttmr010->clkevt.cpumask = cpumask_of(0);
+        fttmr010->clkevt.irq = irq;
+        clockevents_config_and_register(&fttmr010->clkevt,
+                                        fttmr010->tick_rate,
                                         1, 0xffffffff);
 
         return 0;
+
+out_unmap:
+        iounmap(fttmr010->base);
+out_free:
+        kfree(fttmr010);
+out_disable_clock:
+        clk_disable_unprepare(clk);
+
+        return ret;
 }
 CLOCKSOURCE_OF_DECLARE(fttmr010, "faraday,fttmr010", fttmr010_timer_init);
 CLOCKSOURCE_OF_DECLARE(gemini, "cortina,gemini-timer", fttmr010_timer_init);