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1// SPDX-License-Identifier: GPL-2.0-only
2/**
3 * timer-ti-32k.c - OMAP2 32k Timer Support
4 *
5 * Copyright (C) 2009 Nokia Corporation
6 *
7 * Update to use new clocksource/clockevent layers
8 * Author: Kevin Hilman, MontaVista Software, Inc. <source@mvista.com>
9 * Copyright (C) 2007 MontaVista Software, Inc.
10 *
11 * Original driver:
12 * Copyright (C) 2005 Nokia Corporation
13 * Author: Paul Mundt <paul.mundt@nokia.com>
14 * Juha Yrjölä <juha.yrjola@nokia.com>
15 * OMAP Dual-mode timer framework support by Timo Teras
16 *
17 * Some parts based off of TI's 24xx code:
18 *
19 * Copyright (C) 2004-2009 Texas Instruments, Inc.
20 *
21 * Roughly modelled after the OMAP1 MPU timer code.
22 * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
23 *
24 * Copyright (C) 2015 Texas Instruments Incorporated - https://www.ti.com
25 */
26
27#include <linux/clk.h>
28#include <linux/init.h>
29#include <linux/time.h>
30#include <linux/sched_clock.h>
31#include <linux/clocksource.h>
32#include <linux/of.h>
33#include <linux/of_address.h>
34
35/*
36 * 32KHz clocksource ... always available, on pretty most chips except
37 * OMAP 730 and 1510. Other timers could be used as clocksources, with
38 * higher resolution in free-running counter modes (e.g. 12 MHz xtal),
39 * but systems won't necessarily want to spend resources that way.
40 */
41
42#define OMAP2_32KSYNCNT_REV_OFF 0x0
43#define OMAP2_32KSYNCNT_REV_SCHEME (0x3 << 30)
44#define OMAP2_32KSYNCNT_CR_OFF_LOW 0x10
45#define OMAP2_32KSYNCNT_CR_OFF_HIGH 0x30
46
47struct ti_32k {
48 void __iomem *base;
49 void __iomem *counter;
50 struct clocksource cs;
51};
52
53static inline struct ti_32k *to_ti_32k(struct clocksource *cs)
54{
55 return container_of(cs, struct ti_32k, cs);
56}
57
58static u64 notrace ti_32k_read_cycles(struct clocksource *cs)
59{
60 struct ti_32k *ti = to_ti_32k(cs);
61
62 return (u64)readl_relaxed(ti->counter);
63}
64
65static struct ti_32k ti_32k_timer = {
66 .cs = {
67 .name = "32k_counter",
68 .rating = 250,
69 .read = ti_32k_read_cycles,
70 .mask = CLOCKSOURCE_MASK(32),
71 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
72 },
73};
74
75static u64 notrace omap_32k_read_sched_clock(void)
76{
77 return ti_32k_read_cycles(&ti_32k_timer.cs);
78}
79
80static void __init ti_32k_timer_enable_clock(struct device_node *np,
81 const char *name)
82{
83 struct clk *clock;
84 int error;
85
86 clock = of_clk_get_by_name(np->parent, name);
87 if (IS_ERR(clock)) {
88 /* Only some SoCs have a separate interface clock */
89 if (PTR_ERR(clock) == -EINVAL && !strncmp("ick", name, 3))
90 return;
91
92 pr_warn("%s: could not get clock %s %li\n",
93 __func__, name, PTR_ERR(clock));
94 return;
95 }
96
97 error = clk_prepare_enable(clock);
98 if (error) {
99 pr_warn("%s: could not enable %s: %i\n",
100 __func__, name, error);
101 return;
102 }
103}
104
105static void __init ti_32k_timer_module_init(struct device_node *np,
106 void __iomem *base)
107{
108 void __iomem *sysc = base + 4;
109
110 if (!of_device_is_compatible(np->parent, "ti,sysc"))
111 return;
112
113 ti_32k_timer_enable_clock(np, "fck");
114 ti_32k_timer_enable_clock(np, "ick");
115
116 /*
117 * Force idle module as wkup domain is active with MPU.
118 * No need to tag the module disabled for ti-sysc probe.
119 */
120 writel_relaxed(0, sysc);
121}
122
123static int __init ti_32k_timer_init(struct device_node *np)
124{
125 int ret;
126
127 ti_32k_timer.base = of_iomap(np, 0);
128 if (!ti_32k_timer.base) {
129 pr_err("Can't ioremap 32k timer base\n");
130 return -ENXIO;
131 }
132
133 if (!of_machine_is_compatible("ti,am43"))
134 ti_32k_timer.cs.flags |= CLOCK_SOURCE_SUSPEND_NONSTOP;
135
136 ti_32k_timer.counter = ti_32k_timer.base;
137 ti_32k_timer_module_init(np, ti_32k_timer.base);
138
139 /*
140 * 32k sync Counter IP register offsets vary between the highlander
141 * version and the legacy ones.
142 *
143 * The 'SCHEME' bits(30-31) of the revision register is used to identify
144 * the version.
145 */
146 if (readl_relaxed(ti_32k_timer.base + OMAP2_32KSYNCNT_REV_OFF) &
147 OMAP2_32KSYNCNT_REV_SCHEME)
148 ti_32k_timer.counter += OMAP2_32KSYNCNT_CR_OFF_HIGH;
149 else
150 ti_32k_timer.counter += OMAP2_32KSYNCNT_CR_OFF_LOW;
151
152 pr_info("OMAP clocksource: 32k_counter at 32768 Hz\n");
153
154 ret = clocksource_register_hz(&ti_32k_timer.cs, 32768);
155 if (ret) {
156 pr_err("32k_counter: can't register clocksource\n");
157 return ret;
158 }
159
160 sched_clock_register(omap_32k_read_sched_clock, 32, 32768);
161
162 return 0;
163}
164TIMER_OF_DECLARE(ti_32k_timer, "ti,omap-counter32k",
165 ti_32k_timer_init);
1/**
2 * timer-ti-32k.c - OMAP2 32k Timer Support
3 *
4 * Copyright (C) 2009 Nokia Corporation
5 *
6 * Update to use new clocksource/clockevent layers
7 * Author: Kevin Hilman, MontaVista Software, Inc. <source@mvista.com>
8 * Copyright (C) 2007 MontaVista Software, Inc.
9 *
10 * Original driver:
11 * Copyright (C) 2005 Nokia Corporation
12 * Author: Paul Mundt <paul.mundt@nokia.com>
13 * Juha Yrjölä <juha.yrjola@nokia.com>
14 * OMAP Dual-mode timer framework support by Timo Teras
15 *
16 * Some parts based off of TI's 24xx code:
17 *
18 * Copyright (C) 2004-2009 Texas Instruments, Inc.
19 *
20 * Roughly modelled after the OMAP1 MPU timer code.
21 * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
22 *
23 * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
24 *
25 * This program is free software: you can redistribute it and/or modify
26 * it under the terms of the GNU General Public License version 2 of
27 * the License as published by the Free Software Foundation.
28 *
29 * This program is distributed in the hope that it will be useful,
30 * but WITHOUT ANY WARRANTY; without even the implied warranty of
31 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
32 * GNU General Public License for more details.
33 *
34 * You should have received a copy of the GNU General Public License
35 * along with this program. If not, see <http://www.gnu.org/licenses/>.
36 */
37
38#include <linux/init.h>
39#include <linux/time.h>
40#include <linux/sched_clock.h>
41#include <linux/clocksource.h>
42#include <linux/of.h>
43#include <linux/of_address.h>
44
45/*
46 * 32KHz clocksource ... always available, on pretty most chips except
47 * OMAP 730 and 1510. Other timers could be used as clocksources, with
48 * higher resolution in free-running counter modes (e.g. 12 MHz xtal),
49 * but systems won't necessarily want to spend resources that way.
50 */
51
52#define OMAP2_32KSYNCNT_REV_OFF 0x0
53#define OMAP2_32KSYNCNT_REV_SCHEME (0x3 << 30)
54#define OMAP2_32KSYNCNT_CR_OFF_LOW 0x10
55#define OMAP2_32KSYNCNT_CR_OFF_HIGH 0x30
56
57struct ti_32k {
58 void __iomem *base;
59 void __iomem *counter;
60 struct clocksource cs;
61};
62
63static inline struct ti_32k *to_ti_32k(struct clocksource *cs)
64{
65 return container_of(cs, struct ti_32k, cs);
66}
67
68static cycle_t ti_32k_read_cycles(struct clocksource *cs)
69{
70 struct ti_32k *ti = to_ti_32k(cs);
71
72 return (cycle_t)readl_relaxed(ti->counter);
73}
74
75static struct ti_32k ti_32k_timer = {
76 .cs = {
77 .name = "32k_counter",
78 .rating = 250,
79 .read = ti_32k_read_cycles,
80 .mask = CLOCKSOURCE_MASK(32),
81 .flags = CLOCK_SOURCE_IS_CONTINUOUS |
82 CLOCK_SOURCE_SUSPEND_NONSTOP,
83 },
84};
85
86static u64 notrace omap_32k_read_sched_clock(void)
87{
88 return ti_32k_read_cycles(&ti_32k_timer.cs);
89}
90
91static void __init ti_32k_timer_init(struct device_node *np)
92{
93 int ret;
94
95 ti_32k_timer.base = of_iomap(np, 0);
96 if (!ti_32k_timer.base) {
97 pr_err("Can't ioremap 32k timer base\n");
98 return;
99 }
100
101 ti_32k_timer.counter = ti_32k_timer.base;
102
103 /*
104 * 32k sync Counter IP register offsets vary between the highlander
105 * version and the legacy ones.
106 *
107 * The 'SCHEME' bits(30-31) of the revision register is used to identify
108 * the version.
109 */
110 if (readl_relaxed(ti_32k_timer.base + OMAP2_32KSYNCNT_REV_OFF) &
111 OMAP2_32KSYNCNT_REV_SCHEME)
112 ti_32k_timer.counter += OMAP2_32KSYNCNT_CR_OFF_HIGH;
113 else
114 ti_32k_timer.counter += OMAP2_32KSYNCNT_CR_OFF_LOW;
115
116 ret = clocksource_register_hz(&ti_32k_timer.cs, 32768);
117 if (ret) {
118 pr_err("32k_counter: can't register clocksource\n");
119 return;
120 }
121
122 sched_clock_register(omap_32k_read_sched_clock, 32, 32768);
123 pr_info("OMAP clocksource: 32k_counter at 32768 Hz\n");
124}
125CLOCKSOURCE_OF_DECLARE(ti_32k_timer, "ti,omap-counter32k",
126 ti_32k_timer_init);