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path: root/drivers/clocksource/timer-imx-gpt.c
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-rw-r--r--drivers/clocksource/timer-imx-gpt.c542
1 files changed, 542 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-imx-gpt.c b/drivers/clocksource/timer-imx-gpt.c
new file mode 100644
index 000000000..86c7eb66b
--- /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>
+
+/*
+ * 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;
+ imxtm->irq = irq;
+
+ _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(imx27_timer, "fsl,imx27-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);