[PATCH 04/12] clocksource/drivers/stm32: Convert the driver to timer-of
Daniel Lezcano
daniel.lezcano at linaro.org
Thu Jan 4 04:50:20 PST 2018
From: Benjamin Gaignard <benjamin.gaignard at st.com>
Convert the driver to use the timer_of helpers. This allows to remove custom
proprietary structure, factors out and simplifies the code.
[Daniel Lezcano] : Respin against the critical fix patch and massaged the
changelog.
Signed-off-by: Benjamin Gaignard <benjamin.gaignard at st.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano at linaro.org>
---
drivers/clocksource/Kconfig | 1 +
drivers/clocksource/timer-stm32.c | 187 +++++++++++++++-----------------------
2 files changed, 74 insertions(+), 114 deletions(-)
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 9a6b087..786db7a 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -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
diff --git a/drivers/clocksource/timer-stm32.c b/drivers/clocksource/timer-stm32.c
index 4bfeb99..3e4ab07 100644
--- a/drivers/clocksource/timer-stm32.c
+++ b/drivers/clocksource/timer-stm32.c
@@ -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;
-
- data = kmemdup(&clock_event_ddata, sizeof(*data), GFP_KERNEL);
- if (!data)
- 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;
- }
-
- ret = clk_prepare_enable(clk);
- if (ret) {
- pr_err("failed to enable timer clock for clockevent (%d)\n",
- ret);
- goto err_clk_enable;
- }
-
- rate = clk_get_rate(clk);
-
- rstc = of_reset_control_get(np, 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;
- }
+ unsigned long max_delta;
+ int prescaler;
- 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;
- }
+ 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, data->base + TIM_ARR);
- max_delta = readl_relaxed(data->base + TIM_ARR);
+ 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;
- bits = 32;
+ to->clkevt.rating = 250;
} else {
prescaler = 1024;
- bits = 16;
+ to->clkevt.rating = 100;
}
- writel_relaxed(0, data->base + TIM_ARR);
+ writel_relaxed(0, timer_of_base(to) + 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);
+ 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);
- data->periodic_top = DIV_ROUND_CLOSEST(rate, prescaler * HZ);
+ /* 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(&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;
- }
+ clockevents_config_and_register(&to->clkevt,
+ timer_of_rate(to), 0x1, max_delta);
pr_info("%pOF: STM32 clockevent driver initialized (%d bits)\n",
- np, bits);
+ to->np, max_delta == UINT_MAX ? 32 : 16);
+}
- return ret;
+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;
+
+ to->flags = TIMER_OF_IRQ | TIMER_OF_CLOCK | TIMER_OF_BASE;
+ to->of_irq.handler = stm32_clock_event_handler;
+
+ ret = timer_of_init(node, to);
+ if (ret)
+ goto err;
-err_get_irq:
- iounmap(data->base);
-err_iomap:
- clk_disable_unprepare(clk);
-err_clk_enable:
- clk_put(clk);
-err_clk_get:
- kfree(data);
+ rstc = of_reset_control_get(node, NULL);
+ if (!IS_ERR(rstc)) {
+ reset_control_assert(rstc);
+ reset_control_deassert(rstc);
+ }
+
+ 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);
--
2.7.4
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