[PATCH v4 3/4] clocksource/drivers/renesas-ostm: Convert to timer_of

From: Geert Uytterhoeven
Date: Wed Oct 16 2019 - 10:47:57 EST


Convert the Renesas OSTM driver to use the timer_of framework.
This reduces the driver object size by 367 bytes (with gcc 7.4.0).

Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
v4:
- New.

As ARCH_MULTIPLATFORM selects TIMER_OF, timer-of.o was already included,
and thus this conversion does not come with the additional cost of
including timer-of.o:

text data bss dec hex filename
1081 0 0 1081 439 drivers/clocksource/timer-of.o

However, on RZ/A SoCs, timer-of.o was unused before, so this does incur
a theoretical size increase...

Note that the OSTM driver needs TIMER_PROBE (selected by TIMER_OF)
regardless, as it relies on TIMER_OF_DECLARE().
---
drivers/clocksource/Kconfig | 1 +
drivers/clocksource/renesas-ostm.c | 189 +++++++++++------------------
2 files changed, 73 insertions(+), 117 deletions(-)

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index f35a53ce8988a80c..5fdd76cb1768117e 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -528,6 +528,7 @@ config SH_TIMER_MTU2
config RENESAS_OSTM
bool "Renesas OSTM timer driver" if COMPILE_TEST
select CLKSRC_MMIO
+ select TIMER_OF
help
Enables the support for the Renesas OSTM.

diff --git a/drivers/clocksource/renesas-ostm.c b/drivers/clocksource/renesas-ostm.c
index 37c39b901bb12b38..46012d905604bc43 100644
--- a/drivers/clocksource/renesas-ostm.c
+++ b/drivers/clocksource/renesas-ostm.c
@@ -6,14 +6,14 @@
* Copyright (C) 2017 Chris Brandt
*/

-#include <linux/of_address.h>
-#include <linux/of_irq.h>
#include <linux/clk.h>
#include <linux/clockchips.h>
#include <linux/interrupt.h>
#include <linux/sched_clock.h>
#include <linux/slab.h>

+#include "timer-of.h"
+
/*
* The OSTM contains independent channels.
* The first OSTM channel probed will be set up as a free running
@@ -24,12 +24,6 @@
* driven clock event.
*/

-struct ostm_device {
- void __iomem *base;
- unsigned long ticks_per_jiffy;
- struct clock_event_device ced;
-};
-
static void __iomem *system_clock; /* For sched_clock() */

/* OSTM REGISTERS */
@@ -47,41 +41,32 @@ static void __iomem *system_clock; /* For sched_clock() */
#define CTL_ONESHOT 0x02
#define CTL_FREERUN 0x02

-static struct ostm_device *ced_to_ostm(struct clock_event_device *ced)
-{
- return container_of(ced, struct ostm_device, ced);
-}
-
-static void ostm_timer_stop(struct ostm_device *ostm)
+static void ostm_timer_stop(struct timer_of *to)
{
- if (readb(ostm->base + OSTM_TE) & TE) {
- writeb(TT, ostm->base + OSTM_TT);
+ if (readb(timer_of_base(to) + OSTM_TE) & TE) {
+ writeb(TT, timer_of_base(to) + OSTM_TT);

/*
* Read back the register simply to confirm the write operation
* has completed since I/O writes can sometimes get queued by
* the bus architecture.
*/
- while (readb(ostm->base + OSTM_TE) & TE)
+ while (readb(timer_of_base(to) + OSTM_TE) & TE)
;
}
}

-static int __init ostm_init_clksrc(struct ostm_device *ostm, unsigned long rate)
+static int __init ostm_init_clksrc(struct timer_of *to)
{
- /*
- * irq not used (clock sources don't use interrupts)
- */
-
- ostm_timer_stop(ostm);
+ ostm_timer_stop(to);

- writel(0, ostm->base + OSTM_CMP);
- writeb(CTL_FREERUN, ostm->base + OSTM_CTL);
- writeb(TS, ostm->base + OSTM_TS);
+ writel(0, timer_of_base(to) + OSTM_CMP);
+ writeb(CTL_FREERUN, timer_of_base(to) + OSTM_CTL);
+ writeb(TS, timer_of_base(to) + OSTM_TS);

- return clocksource_mmio_init(ostm->base + OSTM_CNT,
- "ostm", rate,
- 300, 32, clocksource_mmio_readl_up);
+ return clocksource_mmio_init(timer_of_base(to) + OSTM_CNT, "ostm",
+ timer_of_rate(to), 300, 32,
+ clocksource_mmio_readl_up);
}

static u64 notrace ostm_read_sched_clock(void)
@@ -89,87 +74,75 @@ static u64 notrace ostm_read_sched_clock(void)
return readl(system_clock);
}

-static void __init ostm_init_sched_clock(struct ostm_device *ostm,
- unsigned long rate)
+static void __init ostm_init_sched_clock(struct timer_of *to)
{
- system_clock = ostm->base + OSTM_CNT;
- sched_clock_register(ostm_read_sched_clock, 32, rate);
+ system_clock = timer_of_base(to) + OSTM_CNT;
+ sched_clock_register(ostm_read_sched_clock, 32, timer_of_rate(to));
}

static int ostm_clock_event_next(unsigned long delta,
- struct clock_event_device *ced)
+ struct clock_event_device *ced)
{
- struct ostm_device *ostm = ced_to_ostm(ced);
+ struct timer_of *to = to_timer_of(ced);

- ostm_timer_stop(ostm);
+ ostm_timer_stop(to);

- writel(delta, ostm->base + OSTM_CMP);
- writeb(CTL_ONESHOT, ostm->base + OSTM_CTL);
- writeb(TS, ostm->base + OSTM_TS);
+ writel(delta, timer_of_base(to) + OSTM_CMP);
+ writeb(CTL_ONESHOT, timer_of_base(to) + OSTM_CTL);
+ writeb(TS, timer_of_base(to) + OSTM_TS);

return 0;
}

static int ostm_shutdown(struct clock_event_device *ced)
{
- struct ostm_device *ostm = ced_to_ostm(ced);
+ struct timer_of *to = to_timer_of(ced);

- ostm_timer_stop(ostm);
+ ostm_timer_stop(to);

return 0;
}
static int ostm_set_periodic(struct clock_event_device *ced)
{
- struct ostm_device *ostm = ced_to_ostm(ced);
+ struct timer_of *to = to_timer_of(ced);

if (clockevent_state_oneshot(ced) || clockevent_state_periodic(ced))
- ostm_timer_stop(ostm);
+ ostm_timer_stop(to);

- writel(ostm->ticks_per_jiffy - 1, ostm->base + OSTM_CMP);
- writeb(CTL_PERIODIC, ostm->base + OSTM_CTL);
- writeb(TS, ostm->base + OSTM_TS);
+ writel(timer_of_period(to) - 1, timer_of_base(to) + OSTM_CMP);
+ writeb(CTL_PERIODIC, timer_of_base(to) + OSTM_CTL);
+ writeb(TS, timer_of_base(to) + OSTM_TS);

return 0;
}

static int ostm_set_oneshot(struct clock_event_device *ced)
{
- struct ostm_device *ostm = ced_to_ostm(ced);
+ struct timer_of *to = to_timer_of(ced);

- ostm_timer_stop(ostm);
+ ostm_timer_stop(to);

return 0;
}

static irqreturn_t ostm_timer_interrupt(int irq, void *dev_id)
{
- struct ostm_device *ostm = dev_id;
+ struct clock_event_device *ced = dev_id;

- if (clockevent_state_oneshot(&ostm->ced))
- ostm_timer_stop(ostm);
+ if (clockevent_state_oneshot(ced))
+ ostm_timer_stop(to_timer_of(ced));

/* notify clockevent layer */
- if (ostm->ced.event_handler)
- ostm->ced.event_handler(&ostm->ced);
+ if (ced->event_handler)
+ ced->event_handler(ced);

return IRQ_HANDLED;
}

-static int __init ostm_init_clkevt(struct ostm_device *ostm, int irq,
- unsigned long rate)
+static int __init ostm_init_clkevt(struct timer_of *to)
{
- struct clock_event_device *ced = &ostm->ced;
- int ret = -ENXIO;
-
- ret = request_irq(irq, ostm_timer_interrupt,
- IRQF_TIMER | IRQF_IRQPOLL,
- "ostm", ostm);
- if (ret) {
- pr_err("ostm: failed to request irq\n");
- return ret;
- }
+ struct clock_event_device *ced = &to->clkevt;

- ced->name = "ostm";
ced->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC;
ced->set_state_shutdown = ostm_shutdown;
ced->set_state_periodic = ostm_set_periodic;
@@ -178,79 +151,61 @@ static int __init ostm_init_clkevt(struct ostm_device *ostm, int irq,
ced->shift = 32;
ced->rating = 300;
ced->cpumask = cpumask_of(0);
- clockevents_config_and_register(ced, rate, 0xf, 0xffffffff);
+ clockevents_config_and_register(ced, timer_of_rate(to), 0xf,
+ 0xffffffff);

return 0;
}

static int __init ostm_init(struct device_node *np)
{
- struct ostm_device *ostm;
- int ret = -EFAULT;
- struct clk *ostm_clk = NULL;
- int irq;
- unsigned long rate;
-
- ostm = kzalloc(sizeof(*ostm), GFP_KERNEL);
- if (!ostm)
- return -ENOMEM;
-
- ostm->base = of_iomap(np, 0);
- if (!ostm->base) {
- pr_err("ostm: failed to remap I/O memory\n");
- goto err;
- }
-
- irq = irq_of_parse_and_map(np, 0);
- if (irq < 0) {
- pr_err("ostm: Failed to get irq\n");
- goto err;
- }
+ struct timer_of *to;
+ int ret;

- ostm_clk = of_clk_get(np, 0);
- if (IS_ERR(ostm_clk)) {
- pr_err("ostm: Failed to get clock\n");
- ostm_clk = NULL;
- goto err;
- }
+ to = kzalloc(sizeof(*to), GFP_KERNEL);
+ if (!to)
+ return -ENOMEM;

- ret = clk_prepare_enable(ostm_clk);
- if (ret) {
- pr_err("ostm: Failed to enable clock\n");
- goto err;
+ to->flags = TIMER_OF_BASE | TIMER_OF_CLOCK;
+ if (system_clock) {
+ /*
+ * clock sources don't use interrupts, clock events do
+ */
+ to->flags |= TIMER_OF_IRQ;
+ to->of_irq.flags = IRQF_TIMER | IRQF_IRQPOLL;
+ to->of_irq.handler = ostm_timer_interrupt;
}

- rate = clk_get_rate(ostm_clk);
- ostm->ticks_per_jiffy = DIV_ROUND_CLOSEST(rate, HZ);
+ ret = timer_of_init(np, to);
+ if (ret)
+ goto err_free;

/*
* First probed device will be used as system clocksource. Any
* additional devices will be used as clock events.
*/
if (!system_clock) {
- ret = ostm_init_clksrc(ostm, rate);
-
- if (!ret) {
- ostm_init_sched_clock(ostm, rate);
- pr_info("ostm: used for clocksource\n");
- }
+ ret = ostm_init_clksrc(to);
+ if (ret)
+ goto err_cleanup;

+ ostm_init_sched_clock(to);
+ pr_info("ostm: used for clocksource\n");
} else {
- ret = ostm_init_clkevt(ostm, irq, rate);
+ ret = ostm_init_clkevt(to);
+ if (ret)
+ goto err_cleanup;

- if (!ret)
- pr_info("ostm: used for clock events\n");
- }
-
-err:
- if (ret) {
- clk_disable_unprepare(ostm_clk);
- iounmap(ostm->base);
- kfree(ostm);
- return ret;
+ pr_info("ostm: used for clock events\n");
}

return 0;
+
+err_cleanup:
+ timer_of_cleanup(to);
+err_free:
+ kfree(to);
+ return ret;
}

TIMER_OF_DECLARE(ostm, "renesas,ostm", ostm_init);
--
2.17.1