ARM: imx: move timer driver into drivers/clocksource

After the cleanup on imx timer driver, now it's ready to be moved into
drivers/clocksource/.  Let's do it.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>

3 files changed, 549 insertions, 0 deletions

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 51d7865fdddb..618102e5aa2a 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -258,4 +258,10 @@ config CLKSRC_PXA
 	help
 	  This enables OST0 support available on PXA and SA-11x0
 	  platforms.
+
+config CLKSRC_IMX_GPT
+	bool "Clocksource using i.MX GPT" if COMPILE_TEST
+	depends on ARM && CLKDEV_LOOKUP
+	select CLKSRC_MMIO
+
 endmenu
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 5b85f6adb258..fce332cac646 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -51,4 +51,5 @@ obj-$(CONFIG_ARCH_KEYSTONE)		+= timer-keystone.o
 obj-$(CONFIG_ARCH_INTEGRATOR_AP)	+= timer-integrator-ap.o
 obj-$(CONFIG_CLKSRC_VERSATILE)		+= versatile.o
 obj-$(CONFIG_CLKSRC_MIPS_GIC)		+= mips-gic-timer.o
+obj-$(CONFIG_CLKSRC_IMX_GPT)		+= timer-imx-gpt.o
 obj-$(CONFIG_ASM9260_TIMER)		+= asm9260_timer.o
diff --git a/drivers/clocksource/timer-imx-gpt.c b/drivers/clocksource/timer-imx-gpt.c
new file mode 100644
index 000000000000..b4609283085b
--- /dev/null
+++ b/drivers/clocksource/timer-imx-gpt.c
@@ -0,0 +1,542 @@
+/*
+ *  linux/arch/arm/plat-mxc/time.c
+ *
+ *  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)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#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>
+#include <soc/imx/timer.h>
+
+#include <asm/mach/time.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+)
+ */
+
+/* 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;
+	enum clock_event_mode cem;
+	struct irqaction act;
+};
+
+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);
+}
+#define imx21_gpt_irq_disable imx1_gpt_irq_disable
+
+static void imx31_gpt_irq_disable(struct imx_timer *imxtm)
+{
+	writel_relaxed(0, imxtm->base + V2_IR);
+}
+#define imx6dl_gpt_irq_disable imx31_gpt_irq_disable
+
+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);
+}
+#define imx21_gpt_irq_enable imx1_gpt_irq_enable
+
+static void imx31_gpt_irq_enable(struct imx_timer *imxtm)
+{
+	writel_relaxed(1<<0, imxtm->base + V2_IR);
+}
+#define imx6dl_gpt_irq_enable imx31_gpt_irq_enable
+
+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);
+}
+#define imx6dl_gpt_irq_acknowledge imx31_gpt_irq_acknowledge
+
+static void __iomem *sched_clock_reg;
+
+static u64 notrace mxc_read_sched_clock(void)
+{
+	return sched_clock_reg ? readl_relaxed(sched_clock_reg) : 0;
+}
+
+static struct delay_timer imx_delay_timer;
+
+static unsigned long imx_read_current_timer(void)
+{
+	return readl_relaxed(sched_clock_reg);
+}
+
+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;
+
+	imx_delay_timer.read_current_timer = &imx_read_current_timer;
+	imx_delay_timer.freq = c;
+	register_current_timer_delay(&imx_delay_timer);
+
+	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;
+}
+
+#ifdef DEBUG
+static const char *clock_event_mode_label[] = {
+	[CLOCK_EVT_MODE_PERIODIC] = "CLOCK_EVT_MODE_PERIODIC",
+	[CLOCK_EVT_MODE_ONESHOT]  = "CLOCK_EVT_MODE_ONESHOT",
+	[CLOCK_EVT_MODE_SHUTDOWN] = "CLOCK_EVT_MODE_SHUTDOWN",
+	[CLOCK_EVT_MODE_UNUSED]   = "CLOCK_EVT_MODE_UNUSED",
+	[CLOCK_EVT_MODE_RESUME]   = "CLOCK_EVT_MODE_RESUME",
+};
+#endif /* DEBUG */
+
+static void mxc_set_mode(enum clock_event_mode mode,
+				struct clock_event_device *ced)
+{
+	struct imx_timer *imxtm = to_imx_timer(ced);
+	unsigned long flags;
+
+	/*
+	 * The timer interrupt generation is disabled at least
+	 * for enough time to call mxc_set_next_event()
+	 */
+	local_irq_save(flags);
+
+	/* Disable interrupt in GPT module */
+	imxtm->gpt->gpt_irq_disable(imxtm);
+
+	if (mode != imxtm->cem) {
+		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 "mxc_set_mode: changing mode from %s to %s\n",
+		clock_event_mode_label[imxtm->cem],
+		clock_event_mode_label[mode]);
+#endif /* DEBUG */
+
+	/* Remember timer mode */
+	imxtm->cem = mode;
+	local_irq_restore(flags);
+
+	switch (mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		printk(KERN_ERR"mxc_set_mode: Periodic mode is not "
+				"supported for i.MX\n");
+		break;
+	case CLOCK_EVT_MODE_ONESHOT:
+	/*
+	 * 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
+	 */
+		local_irq_save(flags);
+		imxtm->gpt->gpt_irq_enable(imxtm);
+		local_irq_restore(flags);
+		break;
+	case CLOCK_EVT_MODE_SHUTDOWN:
+	case CLOCK_EVT_MODE_UNUSED:
+	case CLOCK_EVT_MODE_RESUME:
+		/* Left event sources disabled, no more interrupts appear */
+		break;
+	}
+}
+
+/*
+ * 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;
+	struct irqaction *act = &imxtm->act;
+
+	imxtm->cem = CLOCK_EVT_MODE_UNUSED;
+
+	ced->name = "mxc_timer1";
+	ced->features = CLOCK_EVT_FEAT_ONESHOT;
+	ced->set_mode = mxc_set_mode;
+	ced->set_next_event = imxtm->gpt->set_next_event;
+	ced->rating = 200;
+	ced->cpumask = cpumask_of(0);
+	clockevents_config_and_register(ced, clk_get_rate(imxtm->clk_per),
+					0xff, 0xfffffffe);
+
+	act->name = "i.MX Timer Tick";
+	act->flags = IRQF_TIMER | IRQF_IRQPOLL;
+	act->handler = mxc_timer_interrupt;
+	act->dev_id = ced;
+
+	return setup_irq(imxtm->irq, act);
+}
+
+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);
+}
+#define imx21_gpt_setup_tctl imx1_gpt_setup_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 = imx21_gpt_irq_enable,
+	.gpt_irq_disable = imx21_gpt_irq_disable,
+	.gpt_irq_acknowledge = imx21_gpt_irq_acknowledge,
+	.gpt_setup_tctl = imx21_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 = imx6dl_gpt_irq_enable,
+	.gpt_irq_disable = imx6dl_gpt_irq_disable,
+	.gpt_irq_acknowledge = imx6dl_gpt_irq_acknowledge,
+	.gpt_setup_tctl = imx6dl_gpt_setup_tctl,
+	.set_next_event = v2_set_next_event,
+};
+
+static void __init _mxc_timer_init(struct imx_timer *imxtm)
+{
+	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:
+		BUG();
+	}
+
+	if (IS_ERR(imxtm->clk_per)) {
+		pr_err("i.MX timer: unable to get clk\n");
+		return;
+	}
+
+	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 */
+	mxc_clocksource_init(imxtm);
+	mxc_clockevent_init(imxtm);
+}
+
+void __init mxc_timer_init(unsigned long pbase, int irq, enum imx_gpt_type type)
+{
+	struct imx_timer *imxtm;
+
+	imxtm = kzalloc(sizeof(*imxtm), GFP_KERNEL);
+	BUG_ON(!imxtm);
+
+	imxtm->clk_per = clk_get_sys("imx-gpt.0", "per");
+	imxtm->clk_ipg = clk_get_sys("imx-gpt.0", "ipg");
+
+	imxtm->base = ioremap(pbase, SZ_4K);
+	BUG_ON(!imxtm->base);
+
+	imxtm->type = type;
+
+	_mxc_timer_init(imxtm);
+}
+
+static void __init mxc_timer_init_dt(struct device_node *np,  enum imx_gpt_type type)
+{
+	struct imx_timer *imxtm;
+	static int initialized;
+
+	/* Support one instance only */
+	if (initialized)
+		return;
+
+	imxtm = kzalloc(sizeof(*imxtm), GFP_KERNEL);
+	BUG_ON(!imxtm);
+
+	imxtm->base = of_iomap(np, 0);
+	WARN_ON(!imxtm->base);
+	imxtm->irq = irq_of_parse_and_map(np, 0);
+
+	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;
+
+	_mxc_timer_init(imxtm);
+
+	initialized = 1;
+}
+
+static void __init imx1_timer_init_dt(struct device_node *np)
+{
+	mxc_timer_init_dt(np, GPT_TYPE_IMX1);
+}
+
+static void __init imx21_timer_init_dt(struct device_node *np)
+{
+	mxc_timer_init_dt(np, GPT_TYPE_IMX21);
+}
+
+static void __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;
+
+	mxc_timer_init_dt(np, type);
+}
+
+static void __init imx6dl_timer_init_dt(struct device_node *np)
+{
+	mxc_timer_init_dt(np, GPT_TYPE_IMX6DL);
+}
+
+CLOCKSOURCE_OF_DECLARE(imx1_timer, "fsl,imx1-gpt", imx1_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE(imx21_timer, "fsl,imx21-gpt", imx21_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE(imx31_timer, "fsl,imx31-gpt", imx31_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE(imx25_timer, "fsl,imx25-gpt", imx31_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE(imx50_timer, "fsl,imx50-gpt", imx31_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE(imx51_timer, "fsl,imx51-gpt", imx31_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE(imx53_timer, "fsl,imx53-gpt", imx31_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE(imx6q_timer, "fsl,imx6q-gpt", imx31_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE(imx6dl_timer, "fsl,imx6dl-gpt", imx6dl_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE(imx6sl_timer, "fsl,imx6sl-gpt", imx6dl_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE(imx6sx_timer, "fsl,imx6sx-gpt", imx6dl_timer_init_dt);