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>

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 035981290d964f4d12e66c4fa1d5ef6b00a27390..b3b4ed9b68742bfbb8219af9c24c9d542d6f02ec 100644 (file)
--- 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 4bfeb9929ab2b0f3b7054668230ceaf1646a677f..3e4ab0770293b9d2fd96ed00722ce46acc0f738f 100644 (file)
--- 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);