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-rw-r--r--drivers/clocksource/timer-fttmr010.c459
1 files changed, 459 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-fttmr010.c b/drivers/clocksource/timer-fttmr010.c
new file mode 100644
index 000000000..126fb1f25
--- /dev/null
+++ b/drivers/clocksource/timer-fttmr010.c
@@ -0,0 +1,459 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Faraday Technology FTTMR010 timer driver
+ * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
+ *
+ * Based on a rewrite of arch/arm/mach-gemini/timer.c:
+ * Copyright (C) 2001-2006 Storlink, Corp.
+ * Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
+ */
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/sched_clock.h>
+#include <linux/clk.h>
+#include <linux/slab.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+
+/*
+ * Register definitions common for all the timer variants.
+ */
+#define TIMER1_COUNT (0x00)
+#define TIMER1_LOAD (0x04)
+#define TIMER1_MATCH1 (0x08)
+#define TIMER1_MATCH2 (0x0c)
+#define TIMER2_COUNT (0x10)
+#define TIMER2_LOAD (0x14)
+#define TIMER2_MATCH1 (0x18)
+#define TIMER2_MATCH2 (0x1c)
+#define TIMER3_COUNT (0x20)
+#define TIMER3_LOAD (0x24)
+#define TIMER3_MATCH1 (0x28)
+#define TIMER3_MATCH2 (0x2c)
+#define TIMER_CR (0x30)
+
+/*
+ * Control register set to clear for ast2600 only.
+ */
+#define AST2600_TIMER_CR_CLR (0x3c)
+
+/*
+ * Control register (TMC30) bit fields for fttmr010/gemini/moxart timers.
+ */
+#define TIMER_1_CR_ENABLE BIT(0)
+#define TIMER_1_CR_CLOCK BIT(1)
+#define TIMER_1_CR_INT BIT(2)
+#define TIMER_2_CR_ENABLE BIT(3)
+#define TIMER_2_CR_CLOCK BIT(4)
+#define TIMER_2_CR_INT BIT(5)
+#define TIMER_3_CR_ENABLE BIT(6)
+#define TIMER_3_CR_CLOCK BIT(7)
+#define TIMER_3_CR_INT BIT(8)
+#define TIMER_1_CR_UPDOWN BIT(9)
+#define TIMER_2_CR_UPDOWN BIT(10)
+#define TIMER_3_CR_UPDOWN BIT(11)
+
+/*
+ * Control register (TMC30) bit fields for aspeed ast2400/ast2500 timers.
+ * The aspeed timers move bits around in the control register and lacks
+ * bits for setting the timer to count upwards.
+ */
+#define TIMER_1_CR_ASPEED_ENABLE BIT(0)
+#define TIMER_1_CR_ASPEED_CLOCK BIT(1)
+#define TIMER_1_CR_ASPEED_INT BIT(2)
+#define TIMER_2_CR_ASPEED_ENABLE BIT(4)
+#define TIMER_2_CR_ASPEED_CLOCK BIT(5)
+#define TIMER_2_CR_ASPEED_INT BIT(6)
+#define TIMER_3_CR_ASPEED_ENABLE BIT(8)
+#define TIMER_3_CR_ASPEED_CLOCK BIT(9)
+#define TIMER_3_CR_ASPEED_INT BIT(10)
+
+/*
+ * Interrupt status/mask register definitions for fttmr010/gemini/moxart
+ * timers.
+ * The registers don't exist and they are not needed on aspeed timers
+ * because:
+ * - aspeed timer overflow interrupt is controlled by bits in Control
+ * Register (TMC30).
+ * - aspeed timers always generate interrupt when either one of the
+ * Match registers equals to Status register.
+ */
+#define TIMER_INTR_STATE (0x34)
+#define TIMER_INTR_MASK (0x38)
+#define TIMER_1_INT_MATCH1 BIT(0)
+#define TIMER_1_INT_MATCH2 BIT(1)
+#define TIMER_1_INT_OVERFLOW BIT(2)
+#define TIMER_2_INT_MATCH1 BIT(3)
+#define TIMER_2_INT_MATCH2 BIT(4)
+#define TIMER_2_INT_OVERFLOW BIT(5)
+#define TIMER_3_INT_MATCH1 BIT(6)
+#define TIMER_3_INT_MATCH2 BIT(7)
+#define TIMER_3_INT_OVERFLOW BIT(8)
+#define TIMER_INT_ALL_MASK 0x1ff
+
+struct fttmr010 {
+ void __iomem *base;
+ unsigned int tick_rate;
+ bool is_aspeed;
+ u32 t1_enable_val;
+ struct clock_event_device clkevt;
+ int (*timer_shutdown)(struct clock_event_device *evt);
+#ifdef CONFIG_ARM
+ struct delay_timer delay_timer;
+#endif
+};
+
+/*
+ * A local singleton used by sched_clock and delay timer reads, which are
+ * fast and stateless
+ */
+static struct fttmr010 *local_fttmr;
+
+static inline struct fttmr010 *to_fttmr010(struct clock_event_device *evt)
+{
+ return container_of(evt, struct fttmr010, clkevt);
+}
+
+static unsigned long fttmr010_read_current_timer_up(void)
+{
+ return readl(local_fttmr->base + TIMER2_COUNT);
+}
+
+static unsigned long fttmr010_read_current_timer_down(void)
+{
+ return ~readl(local_fttmr->base + TIMER2_COUNT);
+}
+
+static u64 notrace fttmr010_read_sched_clock_up(void)
+{
+ return fttmr010_read_current_timer_up();
+}
+
+static u64 notrace fttmr010_read_sched_clock_down(void)
+{
+ return fttmr010_read_current_timer_down();
+}
+
+static int fttmr010_timer_set_next_event(unsigned long cycles,
+ struct clock_event_device *evt)
+{
+ struct fttmr010 *fttmr010 = to_fttmr010(evt);
+ u32 cr;
+
+ /* Stop */
+ fttmr010->timer_shutdown(evt);
+
+ if (fttmr010->is_aspeed) {
+ /*
+ * ASPEED Timer Controller will load TIMER1_LOAD register
+ * into TIMER1_COUNT register when the timer is re-enabled.
+ */
+ writel(cycles, fttmr010->base + TIMER1_LOAD);
+ } else {
+ /* Setup the match register forward in time */
+ cr = readl(fttmr010->base + TIMER1_COUNT);
+ writel(cr + cycles, fttmr010->base + TIMER1_MATCH1);
+ }
+
+ /* Start */
+ cr = readl(fttmr010->base + TIMER_CR);
+ cr |= fttmr010->t1_enable_val;
+ writel(cr, fttmr010->base + TIMER_CR);
+
+ return 0;
+}
+
+static int ast2600_timer_shutdown(struct clock_event_device *evt)
+{
+ struct fttmr010 *fttmr010 = to_fttmr010(evt);
+
+ /* Stop */
+ writel(fttmr010->t1_enable_val, fttmr010->base + AST2600_TIMER_CR_CLR);
+
+ return 0;
+}
+
+static int fttmr010_timer_shutdown(struct clock_event_device *evt)
+{
+ struct fttmr010 *fttmr010 = to_fttmr010(evt);
+ u32 cr;
+
+ /* Stop */
+ cr = readl(fttmr010->base + TIMER_CR);
+ cr &= ~fttmr010->t1_enable_val;
+ writel(cr, fttmr010->base + TIMER_CR);
+
+ return 0;
+}
+
+static int fttmr010_timer_set_oneshot(struct clock_event_device *evt)
+{
+ struct fttmr010 *fttmr010 = to_fttmr010(evt);
+ u32 cr;
+
+ /* Stop */
+ fttmr010->timer_shutdown(evt);
+
+ /* Setup counter start from 0 or ~0 */
+ writel(0, fttmr010->base + TIMER1_COUNT);
+ if (fttmr010->is_aspeed) {
+ writel(~0, fttmr010->base + TIMER1_LOAD);
+ } else {
+ writel(0, fttmr010->base + TIMER1_LOAD);
+
+ /* Enable interrupt */
+ cr = readl(fttmr010->base + TIMER_INTR_MASK);
+ cr &= ~(TIMER_1_INT_OVERFLOW | TIMER_1_INT_MATCH2);
+ cr |= TIMER_1_INT_MATCH1;
+ writel(cr, fttmr010->base + TIMER_INTR_MASK);
+ }
+
+ return 0;
+}
+
+static int fttmr010_timer_set_periodic(struct clock_event_device *evt)
+{
+ struct fttmr010 *fttmr010 = to_fttmr010(evt);
+ u32 period = DIV_ROUND_CLOSEST(fttmr010->tick_rate, HZ);
+ u32 cr;
+
+ /* Stop */
+ fttmr010->timer_shutdown(evt);
+
+ /* Setup timer to fire at 1/HZ intervals. */
+ if (fttmr010->is_aspeed) {
+ writel(period, fttmr010->base + TIMER1_LOAD);
+ } else {
+ cr = 0xffffffff - (period - 1);
+ writel(cr, fttmr010->base + TIMER1_COUNT);
+ writel(cr, fttmr010->base + TIMER1_LOAD);
+
+ /* Enable interrupt on overflow */
+ cr = readl(fttmr010->base + TIMER_INTR_MASK);
+ cr &= ~(TIMER_1_INT_MATCH1 | TIMER_1_INT_MATCH2);
+ cr |= TIMER_1_INT_OVERFLOW;
+ writel(cr, fttmr010->base + TIMER_INTR_MASK);
+ }
+
+ /* Start the timer */
+ cr = readl(fttmr010->base + TIMER_CR);
+ cr |= fttmr010->t1_enable_val;
+ writel(cr, fttmr010->base + TIMER_CR);
+
+ return 0;
+}
+
+/*
+ * IRQ handler for the timer
+ */
+static irqreturn_t fttmr010_timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = dev_id;
+
+ evt->event_handler(evt);
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t ast2600_timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = dev_id;
+ struct fttmr010 *fttmr010 = to_fttmr010(evt);
+
+ writel(0x1, fttmr010->base + TIMER_INTR_STATE);
+
+ evt->event_handler(evt);
+ return IRQ_HANDLED;
+}
+
+static int __init fttmr010_common_init(struct device_node *np,
+ bool is_aspeed, bool is_ast2600)
+{
+ struct fttmr010 *fttmr010;
+ int irq;
+ struct clk *clk;
+ int ret;
+ u32 val;
+
+ /*
+ * These implementations require a clock reference.
+ * FIXME: we currently only support clocking using PCLK
+ * and using EXTCLK is not supported in the driver.
+ */
+ clk = of_clk_get_by_name(np, "PCLK");
+ if (IS_ERR(clk)) {
+ pr_err("could not get PCLK\n");
+ return PTR_ERR(clk);
+ }
+ ret = clk_prepare_enable(clk);
+ if (ret) {
+ pr_err("failed to enable PCLK\n");
+ return ret;
+ }
+
+ fttmr010 = kzalloc(sizeof(*fttmr010), GFP_KERNEL);
+ if (!fttmr010) {
+ ret = -ENOMEM;
+ goto out_disable_clock;
+ }
+ fttmr010->tick_rate = clk_get_rate(clk);
+
+ fttmr010->base = of_iomap(np, 0);
+ if (!fttmr010->base) {
+ pr_err("Can't remap registers\n");
+ ret = -ENXIO;
+ goto out_free;
+ }
+ /* IRQ for timer 1 */
+ irq = irq_of_parse_and_map(np, 0);
+ if (irq <= 0) {
+ pr_err("Can't parse IRQ\n");
+ ret = -EINVAL;
+ goto out_unmap;
+ }
+
+ /*
+ * The Aspeed timers move bits around in the control register.
+ */
+ if (is_aspeed) {
+ fttmr010->t1_enable_val = TIMER_1_CR_ASPEED_ENABLE |
+ TIMER_1_CR_ASPEED_INT;
+ fttmr010->is_aspeed = true;
+ } else {
+ fttmr010->t1_enable_val = TIMER_1_CR_ENABLE | TIMER_1_CR_INT;
+
+ /*
+ * Reset the interrupt mask and status
+ */
+ writel(TIMER_INT_ALL_MASK, fttmr010->base + TIMER_INTR_MASK);
+ writel(0, fttmr010->base + TIMER_INTR_STATE);
+ }
+
+ /*
+ * Enable timer 1 count up, timer 2 count up, except on Aspeed,
+ * where everything just counts down.
+ */
+ if (is_aspeed)
+ val = TIMER_2_CR_ASPEED_ENABLE;
+ else {
+ val = TIMER_2_CR_ENABLE | TIMER_1_CR_UPDOWN |
+ TIMER_2_CR_UPDOWN;
+ }
+ writel(val, fttmr010->base + TIMER_CR);
+
+ /*
+ * Setup free-running clocksource timer (interrupts
+ * disabled.)
+ */
+ local_fttmr = fttmr010;
+ writel(0, fttmr010->base + TIMER2_COUNT);
+ writel(0, fttmr010->base + TIMER2_MATCH1);
+ writel(0, fttmr010->base + TIMER2_MATCH2);
+
+ if (fttmr010->is_aspeed) {
+ writel(~0, fttmr010->base + TIMER2_LOAD);
+ clocksource_mmio_init(fttmr010->base + TIMER2_COUNT,
+ "FTTMR010-TIMER2",
+ fttmr010->tick_rate,
+ 300, 32, clocksource_mmio_readl_down);
+ sched_clock_register(fttmr010_read_sched_clock_down, 32,
+ fttmr010->tick_rate);
+ } else {
+ writel(0, fttmr010->base + TIMER2_LOAD);
+ clocksource_mmio_init(fttmr010->base + TIMER2_COUNT,
+ "FTTMR010-TIMER2",
+ fttmr010->tick_rate,
+ 300, 32, clocksource_mmio_readl_up);
+ sched_clock_register(fttmr010_read_sched_clock_up, 32,
+ fttmr010->tick_rate);
+ }
+
+ /*
+ * Setup clockevent timer (interrupt-driven) on timer 1.
+ */
+ writel(0, fttmr010->base + TIMER1_COUNT);
+ writel(0, fttmr010->base + TIMER1_LOAD);
+ writel(0, fttmr010->base + TIMER1_MATCH1);
+ writel(0, fttmr010->base + TIMER1_MATCH2);
+
+ if (is_ast2600) {
+ fttmr010->timer_shutdown = ast2600_timer_shutdown;
+ ret = request_irq(irq, ast2600_timer_interrupt,
+ IRQF_TIMER, "FTTMR010-TIMER1",
+ &fttmr010->clkevt);
+ } else {
+ fttmr010->timer_shutdown = fttmr010_timer_shutdown;
+ ret = request_irq(irq, fttmr010_timer_interrupt,
+ IRQF_TIMER, "FTTMR010-TIMER1",
+ &fttmr010->clkevt);
+ }
+ if (ret) {
+ pr_err("FTTMR010-TIMER1 no IRQ\n");
+ goto out_unmap;
+ }
+
+ fttmr010->clkevt.name = "FTTMR010-TIMER1";
+ /* Reasonably fast and accurate clock event */
+ fttmr010->clkevt.rating = 300;
+ fttmr010->clkevt.features = CLOCK_EVT_FEAT_PERIODIC |
+ CLOCK_EVT_FEAT_ONESHOT;
+ fttmr010->clkevt.set_next_event = fttmr010_timer_set_next_event;
+ fttmr010->clkevt.set_state_shutdown = fttmr010->timer_shutdown;
+ fttmr010->clkevt.set_state_periodic = fttmr010_timer_set_periodic;
+ fttmr010->clkevt.set_state_oneshot = fttmr010_timer_set_oneshot;
+ fttmr010->clkevt.tick_resume = fttmr010->timer_shutdown;
+ fttmr010->clkevt.cpumask = cpumask_of(0);
+ fttmr010->clkevt.irq = irq;
+ clockevents_config_and_register(&fttmr010->clkevt,
+ fttmr010->tick_rate,
+ 1, 0xffffffff);
+
+#ifdef CONFIG_ARM
+ /* Also use this timer for delays */
+ if (fttmr010->is_aspeed)
+ fttmr010->delay_timer.read_current_timer =
+ fttmr010_read_current_timer_down;
+ else
+ fttmr010->delay_timer.read_current_timer =
+ fttmr010_read_current_timer_up;
+ fttmr010->delay_timer.freq = fttmr010->tick_rate;
+ register_current_timer_delay(&fttmr010->delay_timer);
+#endif
+
+ return 0;
+
+out_unmap:
+ iounmap(fttmr010->base);
+out_free:
+ kfree(fttmr010);
+out_disable_clock:
+ clk_disable_unprepare(clk);
+
+ return ret;
+}
+
+static __init int ast2600_timer_init(struct device_node *np)
+{
+ return fttmr010_common_init(np, true, true);
+}
+
+static __init int aspeed_timer_init(struct device_node *np)
+{
+ return fttmr010_common_init(np, true, false);
+}
+
+static __init int fttmr010_timer_init(struct device_node *np)
+{
+ return fttmr010_common_init(np, false, false);
+}
+
+TIMER_OF_DECLARE(fttmr010, "faraday,fttmr010", fttmr010_timer_init);
+TIMER_OF_DECLARE(gemini, "cortina,gemini-timer", fttmr010_timer_init);
+TIMER_OF_DECLARE(moxart, "moxa,moxart-timer", fttmr010_timer_init);
+TIMER_OF_DECLARE(ast2400, "aspeed,ast2400-timer", aspeed_timer_init);
+TIMER_OF_DECLARE(ast2500, "aspeed,ast2500-timer", aspeed_timer_init);
+TIMER_OF_DECLARE(ast2600, "aspeed,ast2600-timer", ast2600_timer_init);