clocksource: qcom: Move clocksource code out of mach-msm

We intend to share the clocksource code for MSM platforms between legacy
and multiplatform supported qcom SoCs.

Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Kumar Gala <galak@codeaurora.org>

3 files changed, 333 insertions, 0 deletions

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index cd6950fd8caf..6510ec4f45ff 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -140,3 +140,6 @@ config VF_PIT_TIMER
         bool
         help
           Support for Period Interrupt Timer on Freescale Vybrid Family SoCs.
+
+config CLKSRC_QCOM
+        bool
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index c7ca50a9c232..2e0c0cc0a014 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -32,6 +32,7 @@ obj-$(CONFIG_CLKSRC_EFM32)	+= time-efm32.o
 obj-$(CONFIG_CLKSRC_EXYNOS_MCT) += exynos_mct.o
 obj-$(CONFIG_CLKSRC_SAMSUNG_PWM)        += samsung_pwm_timer.o
 obj-$(CONFIG_VF_PIT_TIMER)      += vf_pit_timer.o
+obj-$(CONFIG_CLKSRC_QCOM)       += qcom-timer.o
 
 obj-$(CONFIG_ARM_ARCH_TIMER)            += arm_arch_timer.o
 obj-$(CONFIG_ARM_GLOBAL_TIMER)          += arm_global_timer.o
diff --git a/drivers/clocksource/qcom-timer.c b/drivers/clocksource/qcom-timer.c
new file mode 100644
index 000000000000..dca829ec859b
--- /dev/null
+++ b/drivers/clocksource/qcom-timer.c
@@ -0,0 +1,329 @@
+/*
+ *
+ * Copyright (C) 2007 Google, Inc.
+ * Copyright (c) 2009-2012,2014, The Linux Foundation. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/cpu.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/sched_clock.h>
+
+#define TIMER_MATCH_VAL                 0x0000
+#define TIMER_COUNT_VAL                 0x0004
+#define TIMER_ENABLE                    0x0008
+#define TIMER_ENABLE_CLR_ON_MATCH_EN    BIT(1)
+#define TIMER_ENABLE_EN                 BIT(0)
+#define TIMER_CLEAR                     0x000C
+#define DGT_CLK_CTL                     0x10
+#define DGT_CLK_CTL_DIV_4               0x3
+#define TIMER_STS_GPT0_CLR_PEND         BIT(10)
+
+#define GPT_HZ 32768
+
+#define MSM_DGT_SHIFT 5
+
+static void __iomem *event_base;
+static void __iomem *sts_base;
+
+static irqreturn_t msm_timer_interrupt(int irq, void *dev_id)
+{
+        struct clock_event_device *evt = dev_id;
+        /* Stop the timer tick */
+        if (evt->mode == CLOCK_EVT_MODE_ONESHOT) {
+                u32 ctrl = readl_relaxed(event_base + TIMER_ENABLE);
+                ctrl &= ~TIMER_ENABLE_EN;
+                writel_relaxed(ctrl, event_base + TIMER_ENABLE);
+        }
+        evt->event_handler(evt);
+        return IRQ_HANDLED;
+}
+
+static int msm_timer_set_next_event(unsigned long cycles,
+                                    struct clock_event_device *evt)
+{
+        u32 ctrl = readl_relaxed(event_base + TIMER_ENABLE);
+
+        ctrl &= ~TIMER_ENABLE_EN;
+        writel_relaxed(ctrl, event_base + TIMER_ENABLE);
+
+        writel_relaxed(ctrl, event_base + TIMER_CLEAR);
+        writel_relaxed(cycles, event_base + TIMER_MATCH_VAL);
+
+        if (sts_base)
+                while (readl_relaxed(sts_base) & TIMER_STS_GPT0_CLR_PEND)
+                        cpu_relax();
+
+        writel_relaxed(ctrl | TIMER_ENABLE_EN, event_base + TIMER_ENABLE);
+        return 0;
+}
+
+static void msm_timer_set_mode(enum clock_event_mode mode,
+                              struct clock_event_device *evt)
+{
+        u32 ctrl;
+
+        ctrl = readl_relaxed(event_base + TIMER_ENABLE);
+        ctrl &= ~(TIMER_ENABLE_EN | TIMER_ENABLE_CLR_ON_MATCH_EN);
+
+        switch (mode) {
+        case CLOCK_EVT_MODE_RESUME:
+        case CLOCK_EVT_MODE_PERIODIC:
+                break;
+        case CLOCK_EVT_MODE_ONESHOT:
+                /* Timer is enabled in set_next_event */
+                break;
+        case CLOCK_EVT_MODE_UNUSED:
+        case CLOCK_EVT_MODE_SHUTDOWN:
+                break;
+        }
+        writel_relaxed(ctrl, event_base + TIMER_ENABLE);
+}
+
+static struct clock_event_device __percpu *msm_evt;
+
+static void __iomem *source_base;
+
+static notrace cycle_t msm_read_timer_count(struct clocksource *cs)
+{
+        return readl_relaxed(source_base + TIMER_COUNT_VAL);
+}
+
+static notrace cycle_t msm_read_timer_count_shift(struct clocksource *cs)
+{
+        /*
+         * Shift timer count down by a constant due to unreliable lower bits
+         * on some targets.
+         */
+        return msm_read_timer_count(cs) >> MSM_DGT_SHIFT;
+}
+
+static struct clocksource msm_clocksource = {
+        .name   = "dg_timer",
+        .rating = 300,
+        .read   = msm_read_timer_count,
+        .mask   = CLOCKSOURCE_MASK(32),
+        .flags  = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static int msm_timer_irq;
+static int msm_timer_has_ppi;
+
+static int msm_local_timer_setup(struct clock_event_device *evt)
+{
+        int cpu = smp_processor_id();
+        int err;
+
+        evt->irq = msm_timer_irq;
+        evt->name = "msm_timer";
+        evt->features = CLOCK_EVT_FEAT_ONESHOT;
+        evt->rating = 200;
+        evt->set_mode = msm_timer_set_mode;
+        evt->set_next_event = msm_timer_set_next_event;
+        evt->cpumask = cpumask_of(cpu);
+
+        clockevents_config_and_register(evt, GPT_HZ, 4, 0xffffffff);
+
+        if (msm_timer_has_ppi) {
+                enable_percpu_irq(evt->irq, IRQ_TYPE_EDGE_RISING);
+        } else {
+                err = request_irq(evt->irq, msm_timer_interrupt,
+                                IRQF_TIMER | IRQF_NOBALANCING |
+                                IRQF_TRIGGER_RISING, "gp_timer", evt);
+                if (err)
+                        pr_err("request_irq failed\n");
+        }
+
+        return 0;
+}
+
+static void msm_local_timer_stop(struct clock_event_device *evt)
+{
+        evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt);
+        disable_percpu_irq(evt->irq);
+}
+
+static int msm_timer_cpu_notify(struct notifier_block *self,
+                                           unsigned long action, void *hcpu)
+{
+        /*
+         * Grab cpu pointer in each case to avoid spurious
+         * preemptible warnings
+         */
+        switch (action & ~CPU_TASKS_FROZEN) {
+        case CPU_STARTING:
+                msm_local_timer_setup(this_cpu_ptr(msm_evt));
+                break;
+        case CPU_DYING:
+                msm_local_timer_stop(this_cpu_ptr(msm_evt));
+                break;
+        }
+
+        return NOTIFY_OK;
+}
+
+static struct notifier_block msm_timer_cpu_nb = {
+        .notifier_call = msm_timer_cpu_notify,
+};
+
+static u64 notrace msm_sched_clock_read(void)
+{
+        return msm_clocksource.read(&msm_clocksource);
+}
+
+static void __init msm_timer_init(u32 dgt_hz, int sched_bits, int irq,
+                                  bool percpu)
+{
+        struct clocksource *cs = &msm_clocksource;
+        int res = 0;
+
+        msm_timer_irq = irq;
+        msm_timer_has_ppi = percpu;
+
+        msm_evt = alloc_percpu(struct clock_event_device);
+        if (!msm_evt) {
+                pr_err("memory allocation failed for clockevents\n");
+                goto err;
+        }
+
+        if (percpu)
+                res = request_percpu_irq(irq, msm_timer_interrupt,
+                                         "gp_timer", msm_evt);
+
+        if (res) {
+                pr_err("request_percpu_irq failed\n");
+        } else {
+                res = register_cpu_notifier(&msm_timer_cpu_nb);
+                if (res) {
+                        free_percpu_irq(irq, msm_evt);
+                        goto err;
+                }
+
+                /* Immediately configure the timer on the boot CPU */
+                msm_local_timer_setup(__this_cpu_ptr(msm_evt));
+        }
+
+err:
+        writel_relaxed(TIMER_ENABLE_EN, source_base + TIMER_ENABLE);
+        res = clocksource_register_hz(cs, dgt_hz);
+        if (res)
+                pr_err("clocksource_register failed\n");
+        sched_clock_register(msm_sched_clock_read, sched_bits, dgt_hz);
+}
+
+#ifdef CONFIG_OF
+static void __init msm_dt_timer_init(struct device_node *np)
+{
+        u32 freq;
+        int irq;
+        struct resource res;
+        u32 percpu_offset;
+        void __iomem *base;
+        void __iomem *cpu0_base;
+
+        base = of_iomap(np, 0);
+        if (!base) {
+                pr_err("Failed to map event base\n");
+                return;
+        }
+
+        /* We use GPT0 for the clockevent */
+        irq = irq_of_parse_and_map(np, 1);
+        if (irq <= 0) {
+                pr_err("Can't get irq\n");
+                return;
+        }
+
+        /* We use CPU0's DGT for the clocksource */
+        if (of_property_read_u32(np, "cpu-offset", &percpu_offset))
+                percpu_offset = 0;
+
+        if (of_address_to_resource(np, 0, &res)) {
+                pr_err("Failed to parse DGT resource\n");
+                return;
+        }
+
+        cpu0_base = ioremap(res.start + percpu_offset, resource_size(&res));
+        if (!cpu0_base) {
+                pr_err("Failed to map source base\n");
+                return;
+        }
+
+        if (of_property_read_u32(np, "clock-frequency", &freq)) {
+                pr_err("Unknown frequency\n");
+                return;
+        }
+
+        event_base = base + 0x4;
+        sts_base = base + 0x88;
+        source_base = cpu0_base + 0x24;
+        freq /= 4;
+        writel_relaxed(DGT_CLK_CTL_DIV_4, source_base + DGT_CLK_CTL);
+
+        msm_timer_init(freq, 32, irq, !!percpu_offset);
+}
+CLOCKSOURCE_OF_DECLARE(kpss_timer, "qcom,kpss-timer", msm_dt_timer_init);
+CLOCKSOURCE_OF_DECLARE(scss_timer, "qcom,scss-timer", msm_dt_timer_init);
+#endif
+
+static int __init msm_timer_map(phys_addr_t addr, u32 event, u32 source,
+                                u32 sts)
+{
+        void __iomem *base;
+
+        base = ioremap(addr, SZ_256);
+        if (!base) {
+                pr_err("Failed to map timer base\n");
+                return -ENOMEM;
+        }
+        event_base = base + event;
+        source_base = base + source;
+        if (sts)
+                sts_base = base + sts;
+
+        return 0;
+}
+
+void __init msm7x01_timer_init(void)
+{
+        struct clocksource *cs = &msm_clocksource;
+
+        if (msm_timer_map(0xc0100000, 0x0, 0x10, 0x0))
+                return;
+        cs->read = msm_read_timer_count_shift;
+        cs->mask = CLOCKSOURCE_MASK((32 - MSM_DGT_SHIFT));
+        /* 600 KHz */
+        msm_timer_init(19200000 >> MSM_DGT_SHIFT, 32 - MSM_DGT_SHIFT, 7,
+                        false);
+}
+
+void __init msm7x30_timer_init(void)
+{
+        if (msm_timer_map(0xc0100000, 0x4, 0x24, 0x80))
+                return;
+        msm_timer_init(24576000 / 4, 32, 1, false);
+}
+
+void __init qsd8x50_timer_init(void)
+{
+        if (msm_timer_map(0xAC100000, 0x0, 0x10, 0x34))
+                return;
+        msm_timer_init(19200000 / 4, 32, 7, false);
+}