1 files changed, 512 insertions, 0 deletions

diff --git a/drivers/clocksource/timer-imx-gpt.c b/drivers/clocksource/timer-imx-gpt.c
new file mode 100644
index 0000000000..6a878d227a
--- /dev/null
+++ b/drivers/clocksource/timer-imx-gpt.c
@@ -0,0 +1,512 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+//  Copyright (C) 2000-2001 Deep Blue Solutions
+//  Copyright (C) 2002 Shane Nay (shane@minirl.com)
+//  Copyright (C) 2006-2007 Pavel Pisa (ppisa@pikron.com)
+//  Copyright (C) 2008 Juergen Beisert (kernel@pengutronix.de)
+
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/clockchips.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/sched_clock.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+/*
+ * There are 4 versions of the timer hardware on Freescale MXC hardware.
+ *  - MX1/MXL
+ *  - MX21, MX27.
+ *  - MX25, MX31, MX35, MX37, MX51, MX6Q(rev1.0)
+ *  - MX6DL, MX6SX, MX6Q(rev1.1+)
+ */
+enum imx_gpt_type {
+	GPT_TYPE_IMX1,		/* i.MX1 */
+	GPT_TYPE_IMX21,		/* i.MX21/27 */
+	GPT_TYPE_IMX31,		/* i.MX31/35/25/37/51/6Q */
+	GPT_TYPE_IMX6DL,	/* i.MX6DL/SX/SL */
+};
+
+/* defines common for all i.MX */
+#define MXC_TCTL		0x00
+#define MXC_TCTL_TEN		(1 << 0) /* Enable module */
+#define MXC_TPRER		0x04
+
+/* MX1, MX21, MX27 */
+#define MX1_2_TCTL_CLK_PCLK1	(1 << 1)
+#define MX1_2_TCTL_IRQEN	(1 << 4)
+#define MX1_2_TCTL_FRR		(1 << 8)
+#define MX1_2_TCMP		0x08
+#define MX1_2_TCN		0x10
+#define MX1_2_TSTAT		0x14
+
+/* MX21, MX27 */
+#define MX2_TSTAT_CAPT		(1 << 1)
+#define MX2_TSTAT_COMP		(1 << 0)
+
+/* MX31, MX35, MX25, MX5, MX6 */
+#define V2_TCTL_WAITEN		(1 << 3) /* Wait enable mode */
+#define V2_TCTL_CLK_IPG		(1 << 6)
+#define V2_TCTL_CLK_PER		(2 << 6)
+#define V2_TCTL_CLK_OSC_DIV8	(5 << 6)
+#define V2_TCTL_FRR		(1 << 9)
+#define V2_TCTL_24MEN		(1 << 10)
+#define V2_TPRER_PRE24M		12
+#define V2_IR			0x0c
+#define V2_TSTAT		0x08
+#define V2_TSTAT_OF1		(1 << 0)
+#define V2_TCN			0x24
+#define V2_TCMP			0x10
+
+#define V2_TIMER_RATE_OSC_DIV8	3000000
+
+struct imx_timer {
+	enum imx_gpt_type type;
+	void __iomem *base;
+	int irq;
+	struct clk *clk_per;
+	struct clk *clk_ipg;
+	const struct imx_gpt_data *gpt;
+	struct clock_event_device ced;
+};
+
+struct imx_gpt_data {
+	int reg_tstat;
+	int reg_tcn;
+	int reg_tcmp;
+	void (*gpt_setup_tctl)(struct imx_timer *imxtm);
+	void (*gpt_irq_enable)(struct imx_timer *imxtm);
+	void (*gpt_irq_disable)(struct imx_timer *imxtm);
+	void (*gpt_irq_acknowledge)(struct imx_timer *imxtm);
+	int (*set_next_event)(unsigned long evt,
+			      struct clock_event_device *ced);
+};
+
+static inline struct imx_timer *to_imx_timer(struct clock_event_device *ced)
+{
+	return container_of(ced, struct imx_timer, ced);
+}
+
+static void imx1_gpt_irq_disable(struct imx_timer *imxtm)
+{
+	unsigned int tmp;
+
+	tmp = readl_relaxed(imxtm->base + MXC_TCTL);
+	writel_relaxed(tmp & ~MX1_2_TCTL_IRQEN, imxtm->base + MXC_TCTL);
+}
+
+static void imx31_gpt_irq_disable(struct imx_timer *imxtm)
+{
+	writel_relaxed(0, imxtm->base + V2_IR);
+}
+
+static void imx1_gpt_irq_enable(struct imx_timer *imxtm)
+{
+	unsigned int tmp;
+
+	tmp = readl_relaxed(imxtm->base + MXC_TCTL);
+	writel_relaxed(tmp | MX1_2_TCTL_IRQEN, imxtm->base + MXC_TCTL);
+}
+
+static void imx31_gpt_irq_enable(struct imx_timer *imxtm)
+{
+	writel_relaxed(1<<0, imxtm->base + V2_IR);
+}
+
+static void imx1_gpt_irq_acknowledge(struct imx_timer *imxtm)
+{
+	writel_relaxed(0, imxtm->base + MX1_2_TSTAT);
+}
+
+static void imx21_gpt_irq_acknowledge(struct imx_timer *imxtm)
+{
+	writel_relaxed(MX2_TSTAT_CAPT | MX2_TSTAT_COMP,
+				imxtm->base + MX1_2_TSTAT);
+}
+
+static void imx31_gpt_irq_acknowledge(struct imx_timer *imxtm)
+{
+	writel_relaxed(V2_TSTAT_OF1, imxtm->base + V2_TSTAT);
+}
+
+static void __iomem *sched_clock_reg;
+
+static u64 notrace mxc_read_sched_clock(void)
+{
+	return sched_clock_reg ? readl_relaxed(sched_clock_reg) : 0;
+}
+
+#if defined(CONFIG_ARM)
+static struct delay_timer imx_delay_timer;
+
+static unsigned long imx_read_current_timer(void)
+{
+	return readl_relaxed(sched_clock_reg);
+}
+#endif
+
+static int __init mxc_clocksource_init(struct imx_timer *imxtm)
+{
+	unsigned int c = clk_get_rate(imxtm->clk_per);
+	void __iomem *reg = imxtm->base + imxtm->gpt->reg_tcn;
+
+#if defined(CONFIG_ARM)
+	imx_delay_timer.read_current_timer = &imx_read_current_timer;
+	imx_delay_timer.freq = c;
+	register_current_timer_delay(&imx_delay_timer);
+#endif
+
+	sched_clock_reg = reg;
+
+	sched_clock_register(mxc_read_sched_clock, 32, c);
+	return clocksource_mmio_init(reg, "mxc_timer1", c, 200, 32,
+			clocksource_mmio_readl_up);
+}
+
+/* clock event */
+
+static int mx1_2_set_next_event(unsigned long evt,
+			      struct clock_event_device *ced)
+{
+	struct imx_timer *imxtm = to_imx_timer(ced);
+	unsigned long tcmp;
+
+	tcmp = readl_relaxed(imxtm->base + MX1_2_TCN) + evt;
+
+	writel_relaxed(tcmp, imxtm->base + MX1_2_TCMP);
+
+	return (int)(tcmp - readl_relaxed(imxtm->base + MX1_2_TCN)) < 0 ?
+				-ETIME : 0;
+}
+
+static int v2_set_next_event(unsigned long evt,
+			      struct clock_event_device *ced)
+{
+	struct imx_timer *imxtm = to_imx_timer(ced);
+	unsigned long tcmp;
+
+	tcmp = readl_relaxed(imxtm->base + V2_TCN) + evt;
+
+	writel_relaxed(tcmp, imxtm->base + V2_TCMP);
+
+	return evt < 0x7fffffff &&
+		(int)(tcmp - readl_relaxed(imxtm->base + V2_TCN)) < 0 ?
+				-ETIME : 0;
+}
+
+static int mxc_shutdown(struct clock_event_device *ced)
+{
+	struct imx_timer *imxtm = to_imx_timer(ced);
+	u32 tcn;
+
+	/* Disable interrupt in GPT module */
+	imxtm->gpt->gpt_irq_disable(imxtm);
+
+	tcn = readl_relaxed(imxtm->base + imxtm->gpt->reg_tcn);
+	/* Set event time into far-far future */
+	writel_relaxed(tcn - 3, imxtm->base + imxtm->gpt->reg_tcmp);
+
+	/* Clear pending interrupt */
+	imxtm->gpt->gpt_irq_acknowledge(imxtm);
+
+#ifdef DEBUG
+	printk(KERN_INFO "%s: changing mode\n", __func__);
+#endif /* DEBUG */
+
+	return 0;
+}
+
+static int mxc_set_oneshot(struct clock_event_device *ced)
+{
+	struct imx_timer *imxtm = to_imx_timer(ced);
+
+	/* Disable interrupt in GPT module */
+	imxtm->gpt->gpt_irq_disable(imxtm);
+
+	if (!clockevent_state_oneshot(ced)) {
+		u32 tcn = readl_relaxed(imxtm->base + imxtm->gpt->reg_tcn);
+		/* Set event time into far-far future */
+		writel_relaxed(tcn - 3, imxtm->base + imxtm->gpt->reg_tcmp);
+
+		/* Clear pending interrupt */
+		imxtm->gpt->gpt_irq_acknowledge(imxtm);
+	}
+
+#ifdef DEBUG
+	printk(KERN_INFO "%s: changing mode\n", __func__);
+#endif /* DEBUG */
+
+	/*
+	 * Do not put overhead of interrupt enable/disable into
+	 * mxc_set_next_event(), the core has about 4 minutes
+	 * to call mxc_set_next_event() or shutdown clock after
+	 * mode switching
+	 */
+	imxtm->gpt->gpt_irq_enable(imxtm);
+
+	return 0;
+}
+
+/*
+ * IRQ handler for the timer
+ */
+static irqreturn_t mxc_timer_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *ced = dev_id;
+	struct imx_timer *imxtm = to_imx_timer(ced);
+	uint32_t tstat;
+
+	tstat = readl_relaxed(imxtm->base + imxtm->gpt->reg_tstat);
+
+	imxtm->gpt->gpt_irq_acknowledge(imxtm);
+
+	ced->event_handler(ced);
+
+	return IRQ_HANDLED;
+}
+
+static int __init mxc_clockevent_init(struct imx_timer *imxtm)
+{
+	struct clock_event_device *ced = &imxtm->ced;
+
+	ced->name = "mxc_timer1";
+	ced->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_DYNIRQ;
+	ced->set_state_shutdown = mxc_shutdown;
+	ced->set_state_oneshot = mxc_set_oneshot;
+	ced->tick_resume = mxc_shutdown;
+	ced->set_next_event = imxtm->gpt->set_next_event;
+	ced->rating = 200;
+	ced->cpumask = cpumask_of(0);
+	ced->irq = imxtm->irq;
+	clockevents_config_and_register(ced, clk_get_rate(imxtm->clk_per),
+					0xff, 0xfffffffe);
+
+	return request_irq(imxtm->irq, mxc_timer_interrupt,
+			   IRQF_TIMER | IRQF_IRQPOLL, "i.MX Timer Tick", ced);
+}
+
+static void imx1_gpt_setup_tctl(struct imx_timer *imxtm)
+{
+	u32 tctl_val;
+
+	tctl_val = MX1_2_TCTL_FRR | MX1_2_TCTL_CLK_PCLK1 | MXC_TCTL_TEN;
+	writel_relaxed(tctl_val, imxtm->base + MXC_TCTL);
+}
+
+static void imx31_gpt_setup_tctl(struct imx_timer *imxtm)
+{
+	u32 tctl_val;
+
+	tctl_val = V2_TCTL_FRR | V2_TCTL_WAITEN | MXC_TCTL_TEN;
+	if (clk_get_rate(imxtm->clk_per) == V2_TIMER_RATE_OSC_DIV8)
+		tctl_val |= V2_TCTL_CLK_OSC_DIV8;
+	else
+		tctl_val |= V2_TCTL_CLK_PER;
+
+	writel_relaxed(tctl_val, imxtm->base + MXC_TCTL);
+}
+
+static void imx6dl_gpt_setup_tctl(struct imx_timer *imxtm)
+{
+	u32 tctl_val;
+
+	tctl_val = V2_TCTL_FRR | V2_TCTL_WAITEN | MXC_TCTL_TEN;
+	if (clk_get_rate(imxtm->clk_per) == V2_TIMER_RATE_OSC_DIV8) {
+		tctl_val |= V2_TCTL_CLK_OSC_DIV8;
+		/* 24 / 8 = 3 MHz */
+		writel_relaxed(7 << V2_TPRER_PRE24M, imxtm->base + MXC_TPRER);
+		tctl_val |= V2_TCTL_24MEN;
+	} else {
+		tctl_val |= V2_TCTL_CLK_PER;
+	}
+
+	writel_relaxed(tctl_val, imxtm->base + MXC_TCTL);
+}
+
+static const struct imx_gpt_data imx1_gpt_data = {
+	.reg_tstat = MX1_2_TSTAT,
+	.reg_tcn = MX1_2_TCN,
+	.reg_tcmp = MX1_2_TCMP,
+	.gpt_irq_enable = imx1_gpt_irq_enable,
+	.gpt_irq_disable = imx1_gpt_irq_disable,
+	.gpt_irq_acknowledge = imx1_gpt_irq_acknowledge,
+	.gpt_setup_tctl = imx1_gpt_setup_tctl,
+	.set_next_event = mx1_2_set_next_event,
+};
+
+static const struct imx_gpt_data imx21_gpt_data = {
+	.reg_tstat = MX1_2_TSTAT,
+	.reg_tcn = MX1_2_TCN,
+	.reg_tcmp = MX1_2_TCMP,
+	.gpt_irq_enable = imx1_gpt_irq_enable,
+	.gpt_irq_disable = imx1_gpt_irq_disable,
+	.gpt_irq_acknowledge = imx21_gpt_irq_acknowledge,
+	.gpt_setup_tctl = imx1_gpt_setup_tctl,
+	.set_next_event = mx1_2_set_next_event,
+};
+
+static const struct imx_gpt_data imx31_gpt_data = {
+	.reg_tstat = V2_TSTAT,
+	.reg_tcn = V2_TCN,
+	.reg_tcmp = V2_TCMP,
+	.gpt_irq_enable = imx31_gpt_irq_enable,
+	.gpt_irq_disable = imx31_gpt_irq_disable,
+	.gpt_irq_acknowledge = imx31_gpt_irq_acknowledge,
+	.gpt_setup_tctl = imx31_gpt_setup_tctl,
+	.set_next_event = v2_set_next_event,
+};
+
+static const struct imx_gpt_data imx6dl_gpt_data = {
+	.reg_tstat = V2_TSTAT,
+	.reg_tcn = V2_TCN,
+	.reg_tcmp = V2_TCMP,
+	.gpt_irq_enable = imx31_gpt_irq_enable,
+	.gpt_irq_disable = imx31_gpt_irq_disable,
+	.gpt_irq_acknowledge = imx31_gpt_irq_acknowledge,
+	.gpt_setup_tctl = imx6dl_gpt_setup_tctl,
+	.set_next_event = v2_set_next_event,
+};
+
+static int __init _mxc_timer_init(struct imx_timer *imxtm)
+{
+	int ret;
+
+	switch (imxtm->type) {
+	case GPT_TYPE_IMX1:
+		imxtm->gpt = &imx1_gpt_data;
+		break;
+	case GPT_TYPE_IMX21:
+		imxtm->gpt = &imx21_gpt_data;
+		break;
+	case GPT_TYPE_IMX31:
+		imxtm->gpt = &imx31_gpt_data;
+		break;
+	case GPT_TYPE_IMX6DL:
+		imxtm->gpt = &imx6dl_gpt_data;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (IS_ERR(imxtm->clk_per)) {
+		pr_err("i.MX timer: unable to get clk\n");
+		return PTR_ERR(imxtm->clk_per);
+	}
+
+	if (!IS_ERR(imxtm->clk_ipg))
+		clk_prepare_enable(imxtm->clk_ipg);
+
+	clk_prepare_enable(imxtm->clk_per);
+
+	/*
+	 * Initialise to a known state (all timers off, and timing reset)
+	 */
+
+	writel_relaxed(0, imxtm->base + MXC_TCTL);
+	writel_relaxed(0, imxtm->base + MXC_TPRER); /* see datasheet note */
+
+	imxtm->gpt->gpt_setup_tctl(imxtm);
+
+	/* init and register the timer to the framework */
+	ret = mxc_clocksource_init(imxtm);
+	if (ret)
+		return ret;
+
+	return mxc_clockevent_init(imxtm);
+}
+
+static int __init mxc_timer_init_dt(struct device_node *np,  enum imx_gpt_type type)
+{
+	struct imx_timer *imxtm;
+	static int initialized;
+	int ret;
+
+	/* Support one instance only */
+	if (initialized)
+		return 0;
+
+	imxtm = kzalloc(sizeof(*imxtm), GFP_KERNEL);
+	if (!imxtm)
+		return -ENOMEM;
+
+	imxtm->base = of_iomap(np, 0);
+	if (!imxtm->base) {
+		ret = -ENXIO;
+		goto err_kfree;
+	}
+
+	imxtm->irq = irq_of_parse_and_map(np, 0);
+	if (imxtm->irq <= 0) {
+		ret = -EINVAL;
+		goto err_kfree;
+	}
+
+	imxtm->clk_ipg = of_clk_get_by_name(np, "ipg");
+
+	/* Try osc_per first, and fall back to per otherwise */
+	imxtm->clk_per = of_clk_get_by_name(np, "osc_per");
+	if (IS_ERR(imxtm->clk_per))
+		imxtm->clk_per = of_clk_get_by_name(np, "per");
+
+	imxtm->type = type;
+
+	ret = _mxc_timer_init(imxtm);
+	if (ret)
+		goto err_kfree;
+
+	initialized = 1;
+
+	return 0;
+
+err_kfree:
+	kfree(imxtm);
+	return ret;
+}
+
+static int __init imx1_timer_init_dt(struct device_node *np)
+{
+	return mxc_timer_init_dt(np, GPT_TYPE_IMX1);
+}
+
+static int __init imx21_timer_init_dt(struct device_node *np)
+{
+	return mxc_timer_init_dt(np, GPT_TYPE_IMX21);
+}
+
+static int __init imx31_timer_init_dt(struct device_node *np)
+{
+	enum imx_gpt_type type = GPT_TYPE_IMX31;
+
+	/*
+	 * We were using the same compatible string for i.MX6Q/D and i.MX6DL/S
+	 * GPT device, while they actually have different programming model.
+	 * This is a workaround to keep the existing i.MX6DL/S DTBs continue
+	 * working with the new kernel.
+	 */
+	if (of_machine_is_compatible("fsl,imx6dl"))
+		type = GPT_TYPE_IMX6DL;
+
+	return mxc_timer_init_dt(np, type);
+}
+
+static int __init imx6dl_timer_init_dt(struct device_node *np)
+{
+	return mxc_timer_init_dt(np, GPT_TYPE_IMX6DL);
+}
+
+TIMER_OF_DECLARE(imx1_timer, "fsl,imx1-gpt", imx1_timer_init_dt);
+TIMER_OF_DECLARE(imx21_timer, "fsl,imx21-gpt", imx21_timer_init_dt);
+TIMER_OF_DECLARE(imx27_timer, "fsl,imx27-gpt", imx21_timer_init_dt);
+TIMER_OF_DECLARE(imx31_timer, "fsl,imx31-gpt", imx31_timer_init_dt);
+TIMER_OF_DECLARE(imx25_timer, "fsl,imx25-gpt", imx31_timer_init_dt);
+TIMER_OF_DECLARE(imx50_timer, "fsl,imx50-gpt", imx31_timer_init_dt);
+TIMER_OF_DECLARE(imx51_timer, "fsl,imx51-gpt", imx31_timer_init_dt);
+TIMER_OF_DECLARE(imx53_timer, "fsl,imx53-gpt", imx31_timer_init_dt);
+TIMER_OF_DECLARE(imx6q_timer, "fsl,imx6q-gpt", imx31_timer_init_dt);
+TIMER_OF_DECLARE(imx6dl_timer, "fsl,imx6dl-gpt", imx6dl_timer_init_dt);
+TIMER_OF_DECLARE(imx6sl_timer, "fsl,imx6sl-gpt", imx6dl_timer_init_dt);
+TIMER_OF_DECLARE(imx6sx_timer, "fsl,imx6sx-gpt", imx6dl_timer_init_dt);