| // 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); |