[24/29] clocksource/drivers/rockchip_timer: Implement clocksource timer

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 3356ab8..483f3b1 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -81,6 +81,7 @@  config ROCKCHIP_TIMER
 	bool "Rockchip timer driver" if COMPILE_TEST
 	depends on ARM || ARM64
 	select CLKSRC_OF
+	select CLKSRC_MMIO
 	help
 	  Enables the support for the rockchip timer driver.
 
diff --git a/drivers/clocksource/rockchip_timer.c b/drivers/clocksource/rockchip_timer.c
index 23e267a..49c02be 100644
--- a/drivers/clocksource/rockchip_timer.c
+++ b/drivers/clocksource/rockchip_timer.c
@@ -11,6 +11,8 @@ 
 #include <linux/clockchips.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
+#include <linux/sched_clock.h>
+#include <linux/slab.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
@@ -19,6 +21,8 @@ 
 
 #define TIMER_LOAD_COUNT0	0x00
 #define TIMER_LOAD_COUNT1	0x04
+#define TIMER_CURRENT_VALUE0	0x08
+#define TIMER_CURRENT_VALUE1	0x0C
 #define TIMER_CONTROL_REG3288	0x10
 #define TIMER_CONTROL_REG3399	0x1c
 #define TIMER_INT_STATUS	0x18
@@ -29,103 +33,118 @@ 
 #define TIMER_MODE_USER_DEFINED_COUNT		(1 << 1)
 #define TIMER_INT_UNMASK			(1 << 2)
 
-struct bc_timer {
-	struct clock_event_device ce;
+struct rk_timer {
 	void __iomem *base;
 	void __iomem *ctrl;
+	struct clk *clk;
+	struct clk *pclk;
 	u32 freq;
+	int irq;
 };
 
-static struct bc_timer bc_timer;
-
-static inline struct bc_timer *rk_timer(struct clock_event_device *ce)
-{
-	return container_of(ce, struct bc_timer, ce);
-}
+struct rk_clkevt {
+	struct clock_event_device ce;
+	struct rk_timer timer;
+};
 
-static inline void __iomem *rk_base(struct clock_event_device *ce)
-{
-	return rk_timer(ce)->base;
-}
+static struct rk_clkevt *rk_clkevt;
+static struct rk_timer *rk_clksrc;
 
-static inline void __iomem *rk_ctrl(struct clock_event_device *ce)
+static inline struct rk_timer *rk_timer(struct clock_event_device *ce)
 {
-	return rk_timer(ce)->ctrl;
+	return &container_of(ce, struct rk_clkevt, ce)->timer;
 }
 
-static inline void rk_timer_disable(struct clock_event_device *ce)
+static inline void rk_timer_disable(struct rk_timer *timer)
 {
-	writel_relaxed(TIMER_DISABLE, rk_ctrl(ce));
+	writel_relaxed(TIMER_DISABLE, timer->ctrl);
 }
 
-static inline void rk_timer_enable(struct clock_event_device *ce, u32 flags)
+static inline void rk_timer_enable(struct rk_timer *timer, u32 flags)
 {
-	writel_relaxed(TIMER_ENABLE | TIMER_INT_UNMASK | flags,
-		       rk_ctrl(ce));
+	writel_relaxed(TIMER_ENABLE | flags, timer->ctrl);
 }
 
 static void rk_timer_update_counter(unsigned long cycles,
-				    struct clock_event_device *ce)
+				    struct rk_timer *timer)
 {
-	writel_relaxed(cycles, rk_base(ce) + TIMER_LOAD_COUNT0);
-	writel_relaxed(0, rk_base(ce) + TIMER_LOAD_COUNT1);
+	writel_relaxed(cycles, timer->base + TIMER_LOAD_COUNT0);
+	writel_relaxed(0, timer->base + TIMER_LOAD_COUNT1);
 }
 
-static void rk_timer_interrupt_clear(struct clock_event_device *ce)
+static void rk_timer_interrupt_clear(struct rk_timer *timer)
 {
-	writel_relaxed(1, rk_base(ce) + TIMER_INT_STATUS);
+	writel_relaxed(1, timer->base + TIMER_INT_STATUS);
 }
 
 static inline int rk_timer_set_next_event(unsigned long cycles,
 					  struct clock_event_device *ce)
 {
-	rk_timer_disable(ce);
-	rk_timer_update_counter(cycles, ce);
-	rk_timer_enable(ce, TIMER_MODE_USER_DEFINED_COUNT);
+	struct rk_timer *timer = rk_timer(ce);
+
+	rk_timer_disable(timer);
+	rk_timer_update_counter(cycles, timer);
+	rk_timer_enable(timer, TIMER_MODE_USER_DEFINED_COUNT |
+			       TIMER_INT_UNMASK);
 	return 0;
 }
 
 static int rk_timer_shutdown(struct clock_event_device *ce)
 {
-	rk_timer_disable(ce);
+	struct rk_timer *timer = rk_timer(ce);
+
+	rk_timer_disable(timer);
 	return 0;
 }
 
 static int rk_timer_set_periodic(struct clock_event_device *ce)
 {
-	rk_timer_disable(ce);
-	rk_timer_update_counter(rk_timer(ce)->freq / HZ - 1, ce);
-	rk_timer_enable(ce, TIMER_MODE_FREE_RUNNING);
+	struct rk_timer *timer = rk_timer(ce);
+
+	rk_timer_disable(timer);
+	rk_timer_update_counter(timer->freq / HZ - 1, timer);
+	rk_timer_enable(timer, TIMER_MODE_FREE_RUNNING | TIMER_INT_UNMASK);
 	return 0;
 }
 
 static irqreturn_t rk_timer_interrupt(int irq, void *dev_id)
 {
 	struct clock_event_device *ce = dev_id;
+	struct rk_timer *timer = rk_timer(ce);
 
-	rk_timer_interrupt_clear(ce);
+	rk_timer_interrupt_clear(timer);
 
 	if (clockevent_state_oneshot(ce))
-		rk_timer_disable(ce);
+		rk_timer_disable(timer);
 
 	ce->event_handler(ce);
 
 	return IRQ_HANDLED;
 }
 
-static int __init rk_timer_init(struct device_node *np, u32 ctrl_reg)
+static u64 notrace rk_timer_sched_read(void)
+{
+	return ~readl_relaxed(rk_clksrc->base + TIMER_CURRENT_VALUE0);
+}
+
+static int __init
+rk_timer_probe(struct rk_timer *timer, struct device_node *np)
 {
-	struct clock_event_device *ce = &bc_timer.ce;
 	struct clk *timer_clk;
 	struct clk *pclk;
 	int ret = -EINVAL, irq;
+	u32 ctrl_reg = TIMER_CONTROL_REG3288;
 
-	bc_timer.base = of_iomap(np, 0);
-	if (!bc_timer.base) {
+	timer->base = of_iomap(np, 0);
+	if (!timer->base) {
 		pr_err("Failed to get base address for '%s'\n", TIMER_NAME);
 		return -ENXIO;
 	}
-	bc_timer.ctrl = bc_timer.base + ctrl_reg;
+
+	if (of_device_is_compatible(np, "rockchip,rk3399-timer"))
+		ctrl_reg = TIMER_CONTROL_REG3399;
+
+	timer->ctrl = timer->base + ctrl_reg;
 
 	pclk = of_clk_get_by_name(np, "pclk");
 	if (IS_ERR(pclk)) {
@@ -139,6 +158,7 @@  static int __init rk_timer_init(struct device_node *np, u32 ctrl_reg)
 		pr_err("Failed to enable pclk for '%s'\n", TIMER_NAME);
 		goto out_unmap;
 	}
+	timer->pclk = pclk;
 
 	timer_clk = of_clk_get_by_name(np, "timer");
 	if (IS_ERR(timer_clk)) {
@@ -152,8 +172,9 @@  static int __init rk_timer_init(struct device_node *np, u32 ctrl_reg)
 		pr_err("Failed to enable timer clock\n");
 		goto out_timer_clk;
 	}
+	timer->clk = timer_clk;
 
-	bc_timer.freq = clk_get_rate(timer_clk);
+	timer->freq = clk_get_rate(timer_clk);
 
 	irq = irq_of_parse_and_map(np, 0);
 	if (!irq) {
@@ -161,51 +182,126 @@  static int __init rk_timer_init(struct device_node *np, u32 ctrl_reg)
 		pr_err("Failed to map interrupts for '%s'\n", TIMER_NAME);
 		goto out_irq;
 	}
+	timer->irq = irq;
+
+	rk_timer_interrupt_clear(timer);
+	rk_timer_disable(timer);
+	return 0;
+
+out_irq:
+	clk_disable_unprepare(timer_clk);
+out_timer_clk:
+	clk_disable_unprepare(pclk);
+out_unmap:
+	iounmap(timer->base);
+
+	return ret;
+}
+
+static void __init rk_timer_cleanup(struct rk_timer *timer)
+{
+	clk_disable_unprepare(timer->clk);
+	clk_disable_unprepare(timer->pclk);
+	iounmap(timer->base);
+}
+
+static int __init rk_clkevt_init(struct device_node *np)
+{
+	struct clock_event_device *ce;
+	int ret = -EINVAL;
+
+	rk_clkevt = kzalloc(sizeof(struct rk_clkevt), GFP_KERNEL);
+	if (!rk_clkevt) {
+		ret = -ENOMEM;
+		goto out;
+	}
 
+	ret = rk_timer_probe(&rk_clkevt->timer, np);
+	if (ret)
+		goto out_probe;
+
+	ce = &rk_clkevt->ce;
 	ce->name = TIMER_NAME;
 	ce->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT |
 		       CLOCK_EVT_FEAT_DYNIRQ;
 	ce->set_next_event = rk_timer_set_next_event;
 	ce->set_state_shutdown = rk_timer_shutdown;
 	ce->set_state_periodic = rk_timer_set_periodic;
-	ce->irq = irq;
+	ce->irq = rk_clkevt->timer.irq;
 	ce->cpumask = cpu_possible_mask;
 	ce->rating = 250;
 
-	rk_timer_interrupt_clear(ce);
-	rk_timer_disable(ce);
-
-	ret = request_irq(irq, rk_timer_interrupt, IRQF_TIMER, TIMER_NAME, ce);
+	ret = request_irq(rk_clkevt->timer.irq, rk_timer_interrupt, IRQF_TIMER,
+			  TIMER_NAME, ce);
 	if (ret) {
-		pr_err("Failed to initialize '%s': %d\n", TIMER_NAME, ret);
+		pr_err("Failed to initialize '%s': %d\n",
+			TIMER_NAME, ret);
 		goto out_irq;
 	}
 
-	clockevents_config_and_register(ce, bc_timer.freq, 1, UINT_MAX);
-
+	clockevents_config_and_register(&rk_clkevt->ce,
+					rk_clkevt->timer.freq, 1, UINT_MAX);
 	return 0;
 
 out_irq:
-	clk_disable_unprepare(timer_clk);
-out_timer_clk:
-	clk_disable_unprepare(pclk);
-out_unmap:
-	iounmap(bc_timer.base);
-
+	rk_timer_cleanup(&rk_clkevt->timer);
+out_probe:
+	kfree(rk_clkevt);
+out:
+	/* Leave rk_clkevt not NULL to prevent future init */
+	rk_clkevt = ERR_PTR(ret);
 	return ret;
 }
 
-static int __init rk3288_timer_init(struct device_node *np)
+static int __init rk_clksrc_init(struct device_node *np)
 {
-	return rk_timer_init(np, TIMER_CONTROL_REG3288);
+	int ret = -EINVAL;
+
+	rk_clksrc = kzalloc(sizeof(struct rk_timer), GFP_KERNEL);
+	if (!rk_clksrc) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	ret = rk_timer_probe(rk_clksrc, np);
+	if (ret)
+		goto out_probe;
+
+	rk_timer_update_counter(UINT_MAX, rk_clksrc);
+	rk_timer_enable(rk_clksrc, 0);
+
+	ret = clocksource_mmio_init(rk_clksrc->base + TIMER_CURRENT_VALUE0,
+		TIMER_NAME, rk_clksrc->freq, 250, 32,
+		clocksource_mmio_readl_down);
+	if (ret) {
+		pr_err("Failed to register clocksource");
+		goto out_clocksource;
+	}
+
+	sched_clock_register(rk_timer_sched_read, 32, rk_clksrc->freq);
+	return 0;
+
+out_clocksource:
+	rk_timer_cleanup(rk_clksrc);
+out_probe:
+	kfree(rk_clksrc);
+out:
+	/* Leave rk_clksrc not NULL to prevent future init */
+	rk_clksrc = ERR_PTR(ret);
+	return ret;
 }
 
-static int __init rk3399_timer_init(struct device_node *np)
+static int __init rk_timer_init(struct device_node *np)
 {
-	return rk_timer_init(np, TIMER_CONTROL_REG3399);
+	if (!rk_clkevt)
+		return rk_clkevt_init(np);
+
+	if (!rk_clksrc)
+		return rk_clksrc_init(np);
+
+	pr_err("Too many timer definitions for '%s'\n", TIMER_NAME);
+	return -EINVAL;
 }
 
-CLOCKSOURCE_OF_DECLARE(rk3288_timer, "rockchip,rk3288-timer",
-		       rk3288_timer_init);
-CLOCKSOURCE_OF_DECLARE(rk3399_timer, "rockchip,rk3399-timer",
-		       rk3399_timer_init);
+CLOCKSOURCE_OF_DECLARE(rk3288_timer, "rockchip,rk3288-timer", rk_timer_init);
+CLOCKSOURCE_OF_DECLARE(rk3399_timer, "rockchip,rk3399-timer", rk_timer_init);