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path: root/drivers/clocksource/ingenic-sysost.c
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-rw-r--r--drivers/clocksource/ingenic-sysost.c540
1 files changed, 540 insertions, 0 deletions
diff --git a/drivers/clocksource/ingenic-sysost.c b/drivers/clocksource/ingenic-sysost.c
new file mode 100644
index 000000000..cb6fc2f15
--- /dev/null
+++ b/drivers/clocksource/ingenic-sysost.c
@@ -0,0 +1,540 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Ingenic XBurst SoCs SYSOST clocks driver
+ * Copyright (c) 2020 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/sched_clock.h>
+#include <linux/slab.h>
+#include <linux/syscore_ops.h>
+
+#include <dt-bindings/clock/ingenic,sysost.h>
+
+/* OST register offsets */
+#define OST_REG_OSTCCR 0x00
+#define OST_REG_OSTCR 0x08
+#define OST_REG_OSTFR 0x0c
+#define OST_REG_OSTMR 0x10
+#define OST_REG_OST1DFR 0x14
+#define OST_REG_OST1CNT 0x18
+#define OST_REG_OST2CNTL 0x20
+#define OST_REG_OSTCNT2HBUF 0x24
+#define OST_REG_OSTESR 0x34
+#define OST_REG_OSTECR 0x38
+
+/* bits within the OSTCCR register */
+#define OSTCCR_PRESCALE1_MASK 0x3
+#define OSTCCR_PRESCALE2_MASK 0xc
+
+/* bits within the OSTCR register */
+#define OSTCR_OST1CLR BIT(0)
+#define OSTCR_OST2CLR BIT(1)
+
+/* bits within the OSTFR register */
+#define OSTFR_FFLAG BIT(0)
+
+/* bits within the OSTMR register */
+#define OSTMR_FMASK BIT(0)
+
+/* bits within the OSTESR register */
+#define OSTESR_OST1ENS BIT(0)
+#define OSTESR_OST2ENS BIT(1)
+
+/* bits within the OSTECR register */
+#define OSTECR_OST1ENC BIT(0)
+#define OSTECR_OST2ENC BIT(1)
+
+struct ingenic_soc_info {
+ unsigned int num_channels;
+};
+
+struct ingenic_ost_clk_info {
+ struct clk_init_data init_data;
+ u8 ostccr_reg;
+};
+
+struct ingenic_ost_clk {
+ struct clk_hw hw;
+ unsigned int idx;
+ struct ingenic_ost *ost;
+ const struct ingenic_ost_clk_info *info;
+};
+
+struct ingenic_ost {
+ void __iomem *base;
+ const struct ingenic_soc_info *soc_info;
+ struct clk *clk, *percpu_timer_clk, *global_timer_clk;
+ struct clock_event_device cevt;
+ struct clocksource cs;
+ char name[20];
+
+ struct clk_hw_onecell_data *clocks;
+};
+
+static struct ingenic_ost *ingenic_ost;
+
+static inline struct ingenic_ost_clk *to_ost_clk(struct clk_hw *hw)
+{
+ return container_of(hw, struct ingenic_ost_clk, hw);
+}
+
+static unsigned long ingenic_ost_percpu_timer_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct ingenic_ost_clk *ost_clk = to_ost_clk(hw);
+ const struct ingenic_ost_clk_info *info = ost_clk->info;
+ unsigned int prescale;
+
+ prescale = readl(ost_clk->ost->base + info->ostccr_reg);
+
+ prescale = FIELD_GET(OSTCCR_PRESCALE1_MASK, prescale);
+
+ return parent_rate >> (prescale * 2);
+}
+
+static unsigned long ingenic_ost_global_timer_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct ingenic_ost_clk *ost_clk = to_ost_clk(hw);
+ const struct ingenic_ost_clk_info *info = ost_clk->info;
+ unsigned int prescale;
+
+ prescale = readl(ost_clk->ost->base + info->ostccr_reg);
+
+ prescale = FIELD_GET(OSTCCR_PRESCALE2_MASK, prescale);
+
+ return parent_rate >> (prescale * 2);
+}
+
+static u8 ingenic_ost_get_prescale(unsigned long rate, unsigned long req_rate)
+{
+ u8 prescale;
+
+ for (prescale = 0; prescale < 2; prescale++)
+ if ((rate >> (prescale * 2)) <= req_rate)
+ return prescale;
+
+ return 2; /* /16 divider */
+}
+
+static long ingenic_ost_round_rate(struct clk_hw *hw, unsigned long req_rate,
+ unsigned long *parent_rate)
+{
+ unsigned long rate = *parent_rate;
+ u8 prescale;
+
+ if (req_rate > rate)
+ return rate;
+
+ prescale = ingenic_ost_get_prescale(rate, req_rate);
+
+ return rate >> (prescale * 2);
+}
+
+static int ingenic_ost_percpu_timer_set_rate(struct clk_hw *hw, unsigned long req_rate,
+ unsigned long parent_rate)
+{
+ struct ingenic_ost_clk *ost_clk = to_ost_clk(hw);
+ const struct ingenic_ost_clk_info *info = ost_clk->info;
+ u8 prescale = ingenic_ost_get_prescale(parent_rate, req_rate);
+ int val;
+
+ val = readl(ost_clk->ost->base + info->ostccr_reg);
+ val &= ~OSTCCR_PRESCALE1_MASK;
+ val |= FIELD_PREP(OSTCCR_PRESCALE1_MASK, prescale);
+ writel(val, ost_clk->ost->base + info->ostccr_reg);
+
+ return 0;
+}
+
+static int ingenic_ost_global_timer_set_rate(struct clk_hw *hw, unsigned long req_rate,
+ unsigned long parent_rate)
+{
+ struct ingenic_ost_clk *ost_clk = to_ost_clk(hw);
+ const struct ingenic_ost_clk_info *info = ost_clk->info;
+ u8 prescale = ingenic_ost_get_prescale(parent_rate, req_rate);
+ int val;
+
+ val = readl(ost_clk->ost->base + info->ostccr_reg);
+ val &= ~OSTCCR_PRESCALE2_MASK;
+ val |= FIELD_PREP(OSTCCR_PRESCALE2_MASK, prescale);
+ writel(val, ost_clk->ost->base + info->ostccr_reg);
+
+ return 0;
+}
+
+static const struct clk_ops ingenic_ost_percpu_timer_ops = {
+ .recalc_rate = ingenic_ost_percpu_timer_recalc_rate,
+ .round_rate = ingenic_ost_round_rate,
+ .set_rate = ingenic_ost_percpu_timer_set_rate,
+};
+
+static const struct clk_ops ingenic_ost_global_timer_ops = {
+ .recalc_rate = ingenic_ost_global_timer_recalc_rate,
+ .round_rate = ingenic_ost_round_rate,
+ .set_rate = ingenic_ost_global_timer_set_rate,
+};
+
+static const char * const ingenic_ost_clk_parents[] = { "ext" };
+
+static const struct ingenic_ost_clk_info x1000_ost_clk_info[] = {
+ [OST_CLK_PERCPU_TIMER] = {
+ .init_data = {
+ .name = "percpu timer",
+ .parent_names = ingenic_ost_clk_parents,
+ .num_parents = ARRAY_SIZE(ingenic_ost_clk_parents),
+ .ops = &ingenic_ost_percpu_timer_ops,
+ .flags = CLK_SET_RATE_UNGATE,
+ },
+ .ostccr_reg = OST_REG_OSTCCR,
+ },
+
+ [OST_CLK_GLOBAL_TIMER] = {
+ .init_data = {
+ .name = "global timer",
+ .parent_names = ingenic_ost_clk_parents,
+ .num_parents = ARRAY_SIZE(ingenic_ost_clk_parents),
+ .ops = &ingenic_ost_global_timer_ops,
+ .flags = CLK_SET_RATE_UNGATE,
+ },
+ .ostccr_reg = OST_REG_OSTCCR,
+ },
+};
+
+static u64 notrace ingenic_ost_global_timer_read_cntl(void)
+{
+ struct ingenic_ost *ost = ingenic_ost;
+ unsigned int count;
+
+ count = readl(ost->base + OST_REG_OST2CNTL);
+
+ return count;
+}
+
+static u64 notrace ingenic_ost_clocksource_read(struct clocksource *cs)
+{
+ return ingenic_ost_global_timer_read_cntl();
+}
+
+static inline struct ingenic_ost *to_ingenic_ost(struct clock_event_device *evt)
+{
+ return container_of(evt, struct ingenic_ost, cevt);
+}
+
+static int ingenic_ost_cevt_set_state_shutdown(struct clock_event_device *evt)
+{
+ struct ingenic_ost *ost = to_ingenic_ost(evt);
+
+ writel(OSTECR_OST1ENC, ost->base + OST_REG_OSTECR);
+
+ return 0;
+}
+
+static int ingenic_ost_cevt_set_next(unsigned long next,
+ struct clock_event_device *evt)
+{
+ struct ingenic_ost *ost = to_ingenic_ost(evt);
+
+ writel((u32)~OSTFR_FFLAG, ost->base + OST_REG_OSTFR);
+ writel(next, ost->base + OST_REG_OST1DFR);
+ writel(OSTCR_OST1CLR, ost->base + OST_REG_OSTCR);
+ writel(OSTESR_OST1ENS, ost->base + OST_REG_OSTESR);
+ writel((u32)~OSTMR_FMASK, ost->base + OST_REG_OSTMR);
+
+ return 0;
+}
+
+static irqreturn_t ingenic_ost_cevt_cb(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = dev_id;
+ struct ingenic_ost *ost = to_ingenic_ost(evt);
+
+ writel(OSTECR_OST1ENC, ost->base + OST_REG_OSTECR);
+
+ if (evt->event_handler)
+ evt->event_handler(evt);
+
+ return IRQ_HANDLED;
+}
+
+static int __init ingenic_ost_register_clock(struct ingenic_ost *ost,
+ unsigned int idx, const struct ingenic_ost_clk_info *info,
+ struct clk_hw_onecell_data *clocks)
+{
+ struct ingenic_ost_clk *ost_clk;
+ int val, err;
+
+ ost_clk = kzalloc(sizeof(*ost_clk), GFP_KERNEL);
+ if (!ost_clk)
+ return -ENOMEM;
+
+ ost_clk->hw.init = &info->init_data;
+ ost_clk->idx = idx;
+ ost_clk->info = info;
+ ost_clk->ost = ost;
+
+ /* Reset clock divider */
+ val = readl(ost->base + info->ostccr_reg);
+ val &= ~(OSTCCR_PRESCALE1_MASK | OSTCCR_PRESCALE2_MASK);
+ writel(val, ost->base + info->ostccr_reg);
+
+ err = clk_hw_register(NULL, &ost_clk->hw);
+ if (err) {
+ kfree(ost_clk);
+ return err;
+ }
+
+ clocks->hws[idx] = &ost_clk->hw;
+
+ return 0;
+}
+
+static struct clk * __init ingenic_ost_get_clock(struct device_node *np, int id)
+{
+ struct of_phandle_args args;
+
+ args.np = np;
+ args.args_count = 1;
+ args.args[0] = id;
+
+ return of_clk_get_from_provider(&args);
+}
+
+static int __init ingenic_ost_percpu_timer_init(struct device_node *np,
+ struct ingenic_ost *ost)
+{
+ unsigned int timer_virq, channel = OST_CLK_PERCPU_TIMER;
+ unsigned long rate;
+ int err;
+
+ ost->percpu_timer_clk = ingenic_ost_get_clock(np, channel);
+ if (IS_ERR(ost->percpu_timer_clk))
+ return PTR_ERR(ost->percpu_timer_clk);
+
+ err = clk_prepare_enable(ost->percpu_timer_clk);
+ if (err)
+ goto err_clk_put;
+
+ rate = clk_get_rate(ost->percpu_timer_clk);
+ if (!rate) {
+ err = -EINVAL;
+ goto err_clk_disable;
+ }
+
+ timer_virq = of_irq_get(np, 0);
+ if (!timer_virq) {
+ err = -EINVAL;
+ goto err_clk_disable;
+ }
+
+ snprintf(ost->name, sizeof(ost->name), "OST percpu timer");
+
+ err = request_irq(timer_virq, ingenic_ost_cevt_cb, IRQF_TIMER,
+ ost->name, &ost->cevt);
+ if (err)
+ goto err_irq_dispose_mapping;
+
+ ost->cevt.cpumask = cpumask_of(smp_processor_id());
+ ost->cevt.features = CLOCK_EVT_FEAT_ONESHOT;
+ ost->cevt.name = ost->name;
+ ost->cevt.rating = 400;
+ ost->cevt.set_state_shutdown = ingenic_ost_cevt_set_state_shutdown;
+ ost->cevt.set_next_event = ingenic_ost_cevt_set_next;
+
+ clockevents_config_and_register(&ost->cevt, rate, 4, 0xffffffff);
+
+ return 0;
+
+err_irq_dispose_mapping:
+ irq_dispose_mapping(timer_virq);
+err_clk_disable:
+ clk_disable_unprepare(ost->percpu_timer_clk);
+err_clk_put:
+ clk_put(ost->percpu_timer_clk);
+ return err;
+}
+
+static int __init ingenic_ost_global_timer_init(struct device_node *np,
+ struct ingenic_ost *ost)
+{
+ unsigned int channel = OST_CLK_GLOBAL_TIMER;
+ struct clocksource *cs = &ost->cs;
+ unsigned long rate;
+ int err;
+
+ ost->global_timer_clk = ingenic_ost_get_clock(np, channel);
+ if (IS_ERR(ost->global_timer_clk))
+ return PTR_ERR(ost->global_timer_clk);
+
+ err = clk_prepare_enable(ost->global_timer_clk);
+ if (err)
+ goto err_clk_put;
+
+ rate = clk_get_rate(ost->global_timer_clk);
+ if (!rate) {
+ err = -EINVAL;
+ goto err_clk_disable;
+ }
+
+ /* Clear counter CNT registers */
+ writel(OSTCR_OST2CLR, ost->base + OST_REG_OSTCR);
+
+ /* Enable OST channel */
+ writel(OSTESR_OST2ENS, ost->base + OST_REG_OSTESR);
+
+ cs->name = "ingenic-ost";
+ cs->rating = 400;
+ cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
+ cs->mask = CLOCKSOURCE_MASK(32);
+ cs->read = ingenic_ost_clocksource_read;
+
+ err = clocksource_register_hz(cs, rate);
+ if (err)
+ goto err_clk_disable;
+
+ return 0;
+
+err_clk_disable:
+ clk_disable_unprepare(ost->global_timer_clk);
+err_clk_put:
+ clk_put(ost->global_timer_clk);
+ return err;
+}
+
+static const struct ingenic_soc_info x1000_soc_info = {
+ .num_channels = 2,
+};
+
+static const struct of_device_id __maybe_unused ingenic_ost_of_matches[] __initconst = {
+ { .compatible = "ingenic,x1000-ost", .data = &x1000_soc_info },
+ { /* sentinel */ }
+};
+
+static int __init ingenic_ost_probe(struct device_node *np)
+{
+ const struct of_device_id *id = of_match_node(ingenic_ost_of_matches, np);
+ struct ingenic_ost *ost;
+ unsigned int i;
+ int ret;
+
+ ost = kzalloc(sizeof(*ost), GFP_KERNEL);
+ if (!ost)
+ return -ENOMEM;
+
+ ost->base = of_io_request_and_map(np, 0, of_node_full_name(np));
+ if (IS_ERR(ost->base)) {
+ pr_err("%s: Failed to map OST registers\n", __func__);
+ ret = PTR_ERR(ost->base);
+ goto err_free_ost;
+ }
+
+ ost->clk = of_clk_get_by_name(np, "ost");
+ if (IS_ERR(ost->clk)) {
+ ret = PTR_ERR(ost->clk);
+ pr_crit("%s: Cannot get OST clock\n", __func__);
+ goto err_free_ost;
+ }
+
+ ret = clk_prepare_enable(ost->clk);
+ if (ret) {
+ pr_crit("%s: Unable to enable OST clock\n", __func__);
+ goto err_put_clk;
+ }
+
+ ost->soc_info = id->data;
+
+ ost->clocks = kzalloc(struct_size(ost->clocks, hws, ost->soc_info->num_channels),
+ GFP_KERNEL);
+ if (!ost->clocks) {
+ ret = -ENOMEM;
+ goto err_clk_disable;
+ }
+
+ ost->clocks->num = ost->soc_info->num_channels;
+
+ for (i = 0; i < ost->clocks->num; i++) {
+ ret = ingenic_ost_register_clock(ost, i, &x1000_ost_clk_info[i], ost->clocks);
+ if (ret) {
+ pr_crit("%s: Cannot register clock %d\n", __func__, i);
+ goto err_unregister_ost_clocks;
+ }
+ }
+
+ ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, ost->clocks);
+ if (ret) {
+ pr_crit("%s: Cannot add OF clock provider\n", __func__);
+ goto err_unregister_ost_clocks;
+ }
+
+ ingenic_ost = ost;
+
+ return 0;
+
+err_unregister_ost_clocks:
+ for (i = 0; i < ost->clocks->num; i++)
+ if (ost->clocks->hws[i])
+ clk_hw_unregister(ost->clocks->hws[i]);
+ kfree(ost->clocks);
+err_clk_disable:
+ clk_disable_unprepare(ost->clk);
+err_put_clk:
+ clk_put(ost->clk);
+err_free_ost:
+ kfree(ost);
+ return ret;
+}
+
+static int __init ingenic_ost_init(struct device_node *np)
+{
+ struct ingenic_ost *ost;
+ unsigned long rate;
+ int ret;
+
+ ret = ingenic_ost_probe(np);
+ if (ret) {
+ pr_crit("%s: Failed to initialize OST clocks: %d\n", __func__, ret);
+ return ret;
+ }
+
+ of_node_clear_flag(np, OF_POPULATED);
+
+ ost = ingenic_ost;
+ if (IS_ERR(ost))
+ return PTR_ERR(ost);
+
+ ret = ingenic_ost_global_timer_init(np, ost);
+ if (ret) {
+ pr_crit("%s: Unable to init global timer: %x\n", __func__, ret);
+ goto err_free_ingenic_ost;
+ }
+
+ ret = ingenic_ost_percpu_timer_init(np, ost);
+ if (ret)
+ goto err_ost_global_timer_cleanup;
+
+ /* Register the sched_clock at the end as there's no way to undo it */
+ rate = clk_get_rate(ost->global_timer_clk);
+ sched_clock_register(ingenic_ost_global_timer_read_cntl, 32, rate);
+
+ return 0;
+
+err_ost_global_timer_cleanup:
+ clocksource_unregister(&ost->cs);
+ clk_disable_unprepare(ost->global_timer_clk);
+ clk_put(ost->global_timer_clk);
+err_free_ingenic_ost:
+ kfree(ost);
+ return ret;
+}
+
+TIMER_OF_DECLARE(x1000_ost, "ingenic,x1000-ost", ingenic_ost_init);