diff options
Diffstat (limited to 'drivers/clocksource/timer-of.c')
| -rw-r--r-- | drivers/clocksource/timer-of.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-of.c b/drivers/clocksource/timer-of.c new file mode 100644 index 000000000000..f6e7491c873c --- /dev/null +++ b/drivers/clocksource/timer-of.c @@ -0,0 +1,171 @@ +/* + * Copyright (c) 2017, Linaro Ltd. All rights reserved. + * + * Author: Daniel Lezcano <[email protected]> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>. + */ +#include <linux/clk.h> +#include <linux/interrupt.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/slab.h> + +#include "timer-of.h" + +static __init void timer_irq_exit(struct of_timer_irq *of_irq) +{ + struct timer_of *to = container_of(of_irq, struct timer_of, of_irq); + + struct clock_event_device *clkevt = &to->clkevt; + + of_irq->percpu ? free_percpu_irq(of_irq->irq, clkevt) : + free_irq(of_irq->irq, clkevt); +} + +static __init int timer_irq_init(struct device_node *np, + struct of_timer_irq *of_irq) +{ + int ret; + struct timer_of *to = container_of(of_irq, struct timer_of, of_irq); + struct clock_event_device *clkevt = &to->clkevt; + + of_irq->irq = of_irq->name ? of_irq_get_byname(np, of_irq->name): + irq_of_parse_and_map(np, of_irq->index); + if (!of_irq->irq) { + pr_err("Failed to map interrupt for %s\n", np->full_name); + return -EINVAL; + } + + ret = of_irq->percpu ? + request_percpu_irq(of_irq->irq, of_irq->handler, + np->full_name, clkevt) : + request_irq(of_irq->irq, of_irq->handler, + of_irq->flags ? of_irq->flags : IRQF_TIMER, + np->full_name, clkevt); + if (ret) { + pr_err("Failed to request irq %d for %s\n", of_irq->irq, + np->full_name); + return ret; + } + + clkevt->irq = of_irq->irq; + + return 0; +} + +static __init void timer_clk_exit(struct of_timer_clk *of_clk) +{ + of_clk->rate = 0; + clk_disable_unprepare(of_clk->clk); + clk_put(of_clk->clk); +} + +static __init int timer_clk_init(struct device_node *np, + struct of_timer_clk *of_clk) +{ + int ret; + + of_clk->clk = of_clk->name ? of_clk_get_by_name(np, of_clk->name) : + of_clk_get(np, of_clk->index); + if (IS_ERR(of_clk->clk)) { + pr_err("Failed to get clock for %s\n", np->full_name); + return PTR_ERR(of_clk->clk); + } + + ret = clk_prepare_enable(of_clk->clk); + if (ret) { + pr_err("Failed for enable clock for %s\n", np->full_name); + goto out_clk_put; + } + + of_clk->rate = clk_get_rate(of_clk->clk); + if (!of_clk->rate) { + ret = -EINVAL; + pr_err("Failed to get clock rate for %s\n", np->full_name); + goto out_clk_disable; + } + + of_clk->period = DIV_ROUND_UP(of_clk->rate, HZ); +out: + return ret; + +out_clk_disable: + clk_disable_unprepare(of_clk->clk); +out_clk_put: + clk_put(of_clk->clk); + + goto out; +} + +static __init void timer_base_exit(struct of_timer_base *of_base) +{ + iounmap(of_base->base); +} + +static __init int timer_base_init(struct device_node *np, + struct of_timer_base *of_base) +{ + const char *name = of_base->name ? of_base->name : np->full_name; + + of_base->base = of_io_request_and_map(np, of_base->index, name); + if (!of_base->base) { + pr_err("Failed to iomap (%s)\n", name); + return -ENXIO; + } + + return 0; +} + +int __init timer_of_init(struct device_node *np, struct timer_of *to) +{ + int ret = -EINVAL; + int flags = 0; + + if (to->flags & TIMER_OF_BASE) { + ret = timer_base_init(np, &to->of_base); + if (ret) + goto out_fail; + flags |= TIMER_OF_BASE; + } + + if (to->flags & TIMER_OF_CLOCK) { + ret = timer_clk_init(np, &to->of_clk); + if (ret) + goto out_fail; + flags |= TIMER_OF_CLOCK; + } + + if (to->flags & TIMER_OF_IRQ) { + ret = timer_irq_init(np, &to->of_irq); + if (ret) + goto out_fail; + flags |= TIMER_OF_IRQ; + } + + if (!to->clkevt.name) + to->clkevt.name = np->name; + return ret; + +out_fail: + if (flags & TIMER_OF_IRQ) + timer_irq_exit(&to->of_irq); + + if (flags & TIMER_OF_CLOCK) + timer_clk_exit(&to->of_clk); + + if (flags & TIMER_OF_BASE) + timer_base_exit(&to->of_base); + return ret; +} |