diff options
Diffstat (limited to 'drivers/clocksource/ingenic-sysost.c')
| -rw-r--r-- | drivers/clocksource/ingenic-sysost.c | 540 |
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 0000000000..cb6fc2f152 --- /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); |