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clocksource/drivers/stm32: Convert the driver to timer_of primitives 

Convert the driver to use the timer_of() helpers. This allows the removal of
a custom private structure, factors out and simplifies the code.

[Daniel Lezcano]: Respin against the critical fix patch and massaged the changelog.

Tested-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1515418139-23276-12-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Benjamin Gaignard 2018-01-08 14:28:51 +01:00 committed by Ingo Molnar
parent e0aeca3d8c
commit d04af4908a
2 changed files with 79 additions and 119 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
drivers/clocksource/Kconfig
View File

@ -269,6 +269,7 @@ config CLKSRC_STM32
bool "Clocksource for STM32 SoCs" if !ARCH_STM32
depends on OF && ARM && (ARCH_STM32 || COMPILE_TEST)
select CLKSRC_MMIO
select TIMER_OF
config CLKSRC_MPS2
bool "Clocksource for MPS2 SoCs" if COMPILE_TEST

197
drivers/clocksource/timer-stm32.c
View File

@ -16,6 +16,9 @@
#include <linux/of_irq.h>
#include <linux/clk.h>
#include <linux/reset.h>
#include <linux/slab.h>
#include "timer-of.h"
#define TIM_CR1 0x00
#define TIM_DIER 0x0c
@ -34,162 +37,118 @@
#define TIM_EGR_UG BIT(0)
struct stm32_clock_event_ddata {
struct clock_event_device evtdev;
unsigned periodic_top;
void __iomem *base;
};
static int stm32_clock_event_shutdown(struct clock_event_device *evtdev)
static int stm32_clock_event_shutdown(struct clock_event_device *clkevt)
{
struct stm32_clock_event_ddata *data =
container_of(evtdev, struct stm32_clock_event_ddata, evtdev);
void *base = data->base;
struct timer_of *to = to_timer_of(clkevt);
writel_relaxed(0, timer_of_base(to) + TIM_CR1);
writel_relaxed(0, base + TIM_CR1);
return 0;
}
static int stm32_clock_event_set_periodic(struct clock_event_device *evtdev)
static int stm32_clock_event_set_periodic(struct clock_event_device *clkevt)
{
struct stm32_clock_event_ddata *data =
container_of(evtdev, struct stm32_clock_event_ddata, evtdev);
void *base = data->base;
struct timer_of *to = to_timer_of(clkevt);
writel_relaxed(timer_of_period(to), timer_of_base(to) + TIM_ARR);
writel_relaxed(TIM_CR1_ARPE | TIM_CR1_CEN, timer_of_base(to) + TIM_CR1);
writel_relaxed(data->periodic_top, base + TIM_ARR);
writel_relaxed(TIM_CR1_ARPE | TIM_CR1_CEN, base + TIM_CR1);
return 0;
}
static int stm32_clock_event_set_next_event(unsigned long evt,
struct clock_event_device *evtdev)
struct clock_event_device *clkevt)
{
struct stm32_clock_event_ddata *data =
container_of(evtdev, struct stm32_clock_event_ddata, evtdev);
struct timer_of *to = to_timer_of(clkevt);
writel_relaxed(evt, data->base + TIM_ARR);
writel_relaxed(evt, timer_of_base(to) + TIM_ARR);
writel_relaxed(TIM_CR1_ARPE | TIM_CR1_OPM | TIM_CR1_CEN,
data->base + TIM_CR1);
timer_of_base(to) + TIM_CR1);
return 0;
}
static irqreturn_t stm32_clock_event_handler(int irq, void *dev_id)
{
struct stm32_clock_event_ddata *data = dev_id;
struct clock_event_device *clkevt = (struct clock_event_device *)dev_id;
struct timer_of *to = to_timer_of(clkevt);
writel_relaxed(0, data->base + TIM_SR);
writel_relaxed(0, timer_of_base(to) + TIM_SR);
data->evtdev.event_handler(&data->evtdev);
clkevt->event_handler(clkevt);
return IRQ_HANDLED;
}
static struct stm32_clock_event_ddata clock_event_ddata = {
.evtdev = {
.name = "stm32 clockevent",
.features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
.set_state_shutdown = stm32_clock_event_shutdown,
.set_state_periodic = stm32_clock_event_set_periodic,
.set_state_oneshot = stm32_clock_event_shutdown,
.tick_resume = stm32_clock_event_shutdown,
.set_next_event = stm32_clock_event_set_next_event,
.rating = 200,
},
};
static int __init stm32_clockevent_init(struct device_node *np)
static void __init stm32_clockevent_init(struct timer_of *to)
{
struct stm32_clock_event_ddata *data = &clock_event_ddata;
struct clk *clk;
struct reset_control *rstc;
unsigned long rate, max_delta;
int irq, ret, bits, prescaler = 1;
unsigned long max_delta;
int prescaler;
data = kmemdup(&clock_event_ddata, sizeof(*data), GFP_KERNEL);
if (!data)
to->clkevt.name = "stm32_clockevent";
to->clkevt.features = CLOCK_EVT_FEAT_PERIODIC;
to->clkevt.set_state_shutdown = stm32_clock_event_shutdown;
to->clkevt.set_state_periodic = stm32_clock_event_set_periodic;
to->clkevt.set_state_oneshot = stm32_clock_event_shutdown;
to->clkevt.tick_resume = stm32_clock_event_shutdown;
to->clkevt.set_next_event = stm32_clock_event_set_next_event;
/* Detect whether the timer is 16 or 32 bits */
writel_relaxed(~0U, timer_of_base(to) + TIM_ARR);
max_delta = readl_relaxed(timer_of_base(to) + TIM_ARR);
if (max_delta == ~0U) {
prescaler = 1;
to->clkevt.rating = 250;
} else {
prescaler = 1024;
to->clkevt.rating = 100;
}
writel_relaxed(0, timer_of_base(to) + TIM_ARR);
writel_relaxed(prescaler - 1, timer_of_base(to) + TIM_PSC);
writel_relaxed(TIM_EGR_UG, timer_of_base(to) + TIM_EGR);
writel_relaxed(0, timer_of_base(to) + TIM_SR);
writel_relaxed(TIM_DIER_UIE, timer_of_base(to) + TIM_DIER);
/* Adjust rate and period given the prescaler value */
to->of_clk.rate = DIV_ROUND_CLOSEST(to->of_clk.rate, prescaler);
to->of_clk.period = DIV_ROUND_UP(to->of_clk.rate, HZ);
clockevents_config_and_register(&to->clkevt,
timer_of_rate(to), 0x1, max_delta);
pr_info("%pOF: STM32 clockevent driver initialized (%d bits)\n",
to->np, max_delta == UINT_MAX ? 32 : 16);
}
static int __init stm32_timer_init(struct device_node *node)
{
struct reset_control *rstc;
struct timer_of *to;
int ret;
to = kzalloc(sizeof(*to), GFP_KERNEL);
if (!to)
return -ENOMEM;
clk = of_clk_get(np, 0);
if (IS_ERR(clk)) {
ret = PTR_ERR(clk);
pr_err("failed to get clock for clockevent (%d)\n", ret);
goto err_clk_get;
}
to->flags = TIMER_OF_IRQ | TIMER_OF_CLOCK | TIMER_OF_BASE;
to->of_irq.handler = stm32_clock_event_handler;
ret = clk_prepare_enable(clk);
if (ret) {
pr_err("failed to enable timer clock for clockevent (%d)\n",
ret);
goto err_clk_enable;
}
ret = timer_of_init(node, to);
if (ret)
goto err;
rate = clk_get_rate(clk);
rstc = of_reset_control_get(np, NULL);
rstc = of_reset_control_get(node, NULL);
if (!IS_ERR(rstc)) {
reset_control_assert(rstc);
reset_control_deassert(rstc);
}
data->base = of_iomap(np, 0);
if (!data->base) {
ret = -ENXIO;
pr_err("failed to map registers for clockevent\n");
goto err_iomap;
}
irq = irq_of_parse_and_map(np, 0);
if (!irq) {
ret = -EINVAL;
pr_err("%pOF: failed to get irq.\n", np);
goto err_get_irq;
}
/* Detect whether the timer is 16 or 32 bits */
writel_relaxed(~0U, data->base + TIM_ARR);
max_delta = readl_relaxed(data->base + TIM_ARR);
if (max_delta == ~0U) {
prescaler = 1;
bits = 32;
} else {
prescaler = 1024;
bits = 16;
}
writel_relaxed(0, data->base + TIM_ARR);
writel_relaxed(prescaler - 1, data->base + TIM_PSC);
writel_relaxed(TIM_EGR_UG, data->base + TIM_EGR);
writel_relaxed(0, data->base + TIM_SR);
writel_relaxed(TIM_DIER_UIE, data->base + TIM_DIER);
data->periodic_top = DIV_ROUND_CLOSEST(rate, prescaler * HZ);
clockevents_config_and_register(&data->evtdev,
DIV_ROUND_CLOSEST(rate, prescaler),
0x1, max_delta);
ret = request_irq(irq, stm32_clock_event_handler, IRQF_TIMER,
"stm32 clockevent", data);
if (ret) {
pr_err("%pOF: failed to request irq.\n", np);
goto err_get_irq;
}
pr_info("%pOF: STM32 clockevent driver initialized (%d bits)\n",
np, bits);
return ret;
err_get_irq:
iounmap(data->base);
err_iomap:
clk_disable_unprepare(clk);
err_clk_enable:
clk_put(clk);
err_clk_get:
kfree(data);
stm32_clockevent_init(to);
return 0;
err:
kfree(to);
return ret;
}
TIMER_OF_DECLARE(stm32, "st,stm32-timer", stm32_clockevent_init);
TIMER_OF_DECLARE(stm32, "st,stm32-timer", stm32_timer_init);