[PATCH 4/8 v2] clocksource/drivers/fttmr010: Use state container

From: Linus Walleij
Date: Thu May 18 2017 - 16:18:40 EST

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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@xxxxxxxxx>
Tested-by: Jonas Jensen <jonas.jensen@xxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
ChangeLog v1->v2:
- Added Jonas' Tested-by, no functional changes.
---
drivers/clocksource/timer-fttmr010.c | 190 +++++++++++++++++++++--------------
1 file 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);
--
2.9.3

Next message: Linus Walleij: "[PATCH 1/8 v2] clocksource/drivers/fttmr010: Fix the clock handling"
Previous message: Linus Walleij: "[PATCH 6/8 v2] clocksource/drivers/fttmr010: Switch to use TIMER2 src"
In reply to: Linus Walleij: "[PATCH 6/8 v2] clocksource/drivers/fttmr010: Switch to use TIMER2 src"
Next in thread: Linus Walleij: "[PATCH 2/8 v2] clocksource/drivers/fttmr010: Merge FTTMR010 DT bindings"
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