projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| f0b7fabe AS |
1 | /* |
| 2 | * Cirrus Logic CLPS711X clocksource driver | |
| 3 | * | |
| 4 | * Copyright (C) 2014 Alexander Shiyan <[email protected]> | |
| 5 | * | |
| 6 | * This program is free software; you can redistribute it and/or modify | |
| 7 | * it under the terms of the GNU General Public License as published by | |
| 8 | * the Free Software Foundation; either version 2 of the License, or | |
| 9 | * (at your option) any later version. | |
| 10 | */ | |
| 11 | ||
| 12 | #include <linux/clk.h> | |
| 13 | #include <linux/clockchips.h> | |
| 14 | #include <linux/clocksource.h> | |
| 15 | #include <linux/interrupt.h> | |
| 16 | #include <linux/io.h> | |
| 17 | #include <linux/of_address.h> | |
| 18 | #include <linux/of_irq.h> | |
| 19 | #include <linux/sched_clock.h> | |
| 20 | #include <linux/slab.h> | |
| 21 | ||
| 22 | enum { | |
| 23 | CLPS711X_CLKSRC_CLOCKSOURCE, | |
| 24 | CLPS711X_CLKSRC_CLOCKEVENT, | |
| 25 | }; | |
| 26 | ||
| 27 | static void __iomem *tcd; | |
| 28 | ||
| 29 | static u64 notrace clps711x_sched_clock_read(void) | |
| 30 | { | |
| 31 | return ~readw(tcd); | |
| 32 | } | |
| 33 | ||
| 34 | static int __init _clps711x_clksrc_init(struct clk *clock, void __iomem *base) | |
| 35 | { | |
| 36 | unsigned long rate; | |
| 37 | ||
| 38 | if (!base) | |
| 39 | return -ENOMEM; | |
| 40 | if (IS_ERR(clock)) | |
| 41 | return PTR_ERR(clock); | |
| 42 | ||
| 43 | rate = clk_get_rate(clock); | |
| 44 | ||
| 45 | tcd = base; | |
| 46 | ||
| 47 | clocksource_mmio_init(tcd, "clps711x-clocksource", rate, 300, 16, | |
| 48 | clocksource_mmio_readw_down); | |
| 49 | ||
| 50 | sched_clock_register(clps711x_sched_clock_read, 16, rate); | |
| 51 | ||
| 52 | return 0; | |
| 53 | } | |
| 54 | ||
| 55 | static irqreturn_t clps711x_timer_interrupt(int irq, void *dev_id) | |
| 56 | { | |
| 57 | struct clock_event_device *evt = dev_id; | |
| 58 | ||
| 59 | evt->event_handler(evt); | |
| 60 | ||
| 61 | return IRQ_HANDLED; | |
| 62 | } | |
| 63 | ||
| 64 | static void clps711x_clockevent_set_mode(enum clock_event_mode mode, | |
| 65 | struct clock_event_device *evt) | |
| 66 | { | |
| 67 | } | |
| 68 | ||
| 69 | static int __init _clps711x_clkevt_init(struct clk *clock, void __iomem *base, | |
| 70 | unsigned int irq) | |
| 71 | { | |
| 72 | struct clock_event_device *clkevt; | |
| 73 | unsigned long rate; | |
| 74 | ||
| 75 | if (!irq) | |
| 76 | return -EINVAL; | |
| 77 | if (!base) | |
| 78 | return -ENOMEM; | |
| 79 | if (IS_ERR(clock)) | |
| 80 | return PTR_ERR(clock); | |
| 81 | ||
| 82 | clkevt = kzalloc(sizeof(*clkevt), GFP_KERNEL); | |
| 83 | if (!clkevt) | |
| 84 | return -ENOMEM; | |
| 85 | ||
| 86 | rate = clk_get_rate(clock); | |
| 87 | ||
| 88 | /* Set Timer prescaler */ | |
| 89 | writew(DIV_ROUND_CLOSEST(rate, HZ), base); | |
| 90 | ||
| 91 | clkevt->name = "clps711x-clockevent"; | |
| 92 | clkevt->rating = 300; | |
| 93 | clkevt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_C3STOP; | |
| 94 | clkevt->set_mode = clps711x_clockevent_set_mode; | |
| 95 | clkevt->cpumask = cpumask_of(0); | |
| 96 | clockevents_config_and_register(clkevt, HZ, 0, 0); | |
| 97 | ||
| 98 | return request_irq(irq, clps711x_timer_interrupt, IRQF_TIMER, | |
| 99 | "clps711x-timer", clkevt); | |
| 100 | } | |
| 101 | ||
| 102 | void __init clps711x_clksrc_init(void __iomem *tc1_base, void __iomem *tc2_base, | |
| 103 | unsigned int irq) | |
| 104 | { | |
| 105 | struct clk *tc1 = clk_get_sys("clps711x-timer.0", NULL); | |
| 106 | struct clk *tc2 = clk_get_sys("clps711x-timer.1", NULL); | |
| 107 | ||
| 108 | BUG_ON(_clps711x_clksrc_init(tc1, tc1_base)); | |
| 109 | BUG_ON(_clps711x_clkevt_init(tc2, tc2_base, irq)); | |
| 110 | } | |
| 111 | ||
| 112 | #ifdef CONFIG_CLKSRC_OF | |
| 113 | static void __init clps711x_timer_init(struct device_node *np) | |
| 114 | { | |
| 115 | unsigned int irq = irq_of_parse_and_map(np, 0); | |
| 116 | struct clk *clock = of_clk_get(np, 0); | |
| 117 | void __iomem *base = of_iomap(np, 0); | |
| 118 | ||
| 119 | switch (of_alias_get_id(np, "timer")) { | |
| 120 | case CLPS711X_CLKSRC_CLOCKSOURCE: | |
| 121 | BUG_ON(_clps711x_clksrc_init(clock, base)); | |
| 122 | break; | |
| 123 | case CLPS711X_CLKSRC_CLOCKEVENT: | |
| 124 | BUG_ON(_clps711x_clkevt_init(clock, base, irq)); | |
| 125 | break; | |
| 126 | default: | |
| 127 | break; | |
| 128 | } | |
| 129 | } | |
| 130 | CLOCKSOURCE_OF_DECLARE(clps711x, "cirrus,clps711x-timer", clps711x_timer_init); | |
| 131 | #endif |