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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
4750535b | 2 | /* |
f5bf0ee4 | 3 | * Faraday Technology FTTMR010 timer driver |
4750535b LW |
4 | * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org> |
5 | * | |
6 | * Based on a rewrite of arch/arm/mach-gemini/timer.c: | |
7 | * Copyright (C) 2001-2006 Storlink, Corp. | |
8 | * Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt> | |
9 | */ | |
10 | #include <linux/interrupt.h> | |
11 | #include <linux/io.h> | |
12 | #include <linux/of.h> | |
13 | #include <linux/of_address.h> | |
14 | #include <linux/of_irq.h> | |
4750535b LW |
15 | #include <linux/clockchips.h> |
16 | #include <linux/clocksource.h> | |
17 | #include <linux/sched_clock.h> | |
28e71e2f | 18 | #include <linux/clk.h> |
e7bad212 | 19 | #include <linux/slab.h> |
d0d76d57 | 20 | #include <linux/bitops.h> |
385c98fc | 21 | #include <linux/delay.h> |
4750535b LW |
22 | |
23 | /* | |
24 | * Register definitions for the timers | |
25 | */ | |
26 | #define TIMER1_COUNT (0x00) | |
27 | #define TIMER1_LOAD (0x04) | |
28 | #define TIMER1_MATCH1 (0x08) | |
29 | #define TIMER1_MATCH2 (0x0c) | |
30 | #define TIMER2_COUNT (0x10) | |
31 | #define TIMER2_LOAD (0x14) | |
32 | #define TIMER2_MATCH1 (0x18) | |
33 | #define TIMER2_MATCH2 (0x1c) | |
34 | #define TIMER3_COUNT (0x20) | |
35 | #define TIMER3_LOAD (0x24) | |
36 | #define TIMER3_MATCH1 (0x28) | |
37 | #define TIMER3_MATCH2 (0x2c) | |
38 | #define TIMER_CR (0x30) | |
39 | #define TIMER_INTR_STATE (0x34) | |
40 | #define TIMER_INTR_MASK (0x38) | |
41 | ||
d0d76d57 LW |
42 | #define TIMER_1_CR_ENABLE BIT(0) |
43 | #define TIMER_1_CR_CLOCK BIT(1) | |
44 | #define TIMER_1_CR_INT BIT(2) | |
45 | #define TIMER_2_CR_ENABLE BIT(3) | |
46 | #define TIMER_2_CR_CLOCK BIT(4) | |
47 | #define TIMER_2_CR_INT BIT(5) | |
48 | #define TIMER_3_CR_ENABLE BIT(6) | |
49 | #define TIMER_3_CR_CLOCK BIT(7) | |
50 | #define TIMER_3_CR_INT BIT(8) | |
51 | #define TIMER_1_CR_UPDOWN BIT(9) | |
52 | #define TIMER_2_CR_UPDOWN BIT(10) | |
53 | #define TIMER_3_CR_UPDOWN BIT(11) | |
4750535b | 54 | |
ec14ba1e LW |
55 | /* |
56 | * The Aspeed AST2400 moves bits around in the control register | |
57 | * and lacks bits for setting the timer to count upwards. | |
58 | */ | |
59 | #define TIMER_1_CR_ASPEED_ENABLE BIT(0) | |
60 | #define TIMER_1_CR_ASPEED_CLOCK BIT(1) | |
61 | #define TIMER_1_CR_ASPEED_INT BIT(2) | |
62 | #define TIMER_2_CR_ASPEED_ENABLE BIT(4) | |
63 | #define TIMER_2_CR_ASPEED_CLOCK BIT(5) | |
64 | #define TIMER_2_CR_ASPEED_INT BIT(6) | |
65 | #define TIMER_3_CR_ASPEED_ENABLE BIT(8) | |
66 | #define TIMER_3_CR_ASPEED_CLOCK BIT(9) | |
67 | #define TIMER_3_CR_ASPEED_INT BIT(10) | |
68 | ||
d0d76d57 LW |
69 | #define TIMER_1_INT_MATCH1 BIT(0) |
70 | #define TIMER_1_INT_MATCH2 BIT(1) | |
71 | #define TIMER_1_INT_OVERFLOW BIT(2) | |
72 | #define TIMER_2_INT_MATCH1 BIT(3) | |
73 | #define TIMER_2_INT_MATCH2 BIT(4) | |
74 | #define TIMER_2_INT_OVERFLOW BIT(5) | |
75 | #define TIMER_3_INT_MATCH1 BIT(6) | |
76 | #define TIMER_3_INT_MATCH2 BIT(7) | |
77 | #define TIMER_3_INT_OVERFLOW BIT(8) | |
4750535b LW |
78 | #define TIMER_INT_ALL_MASK 0x1ff |
79 | ||
e7bad212 LW |
80 | struct fttmr010 { |
81 | void __iomem *base; | |
82 | unsigned int tick_rate; | |
ec14ba1e LW |
83 | bool count_down; |
84 | u32 t1_enable_val; | |
e7bad212 | 85 | struct clock_event_device clkevt; |
385c98fc LW |
86 | #ifdef CONFIG_ARM |
87 | struct delay_timer delay_timer; | |
88 | #endif | |
e7bad212 LW |
89 | }; |
90 | ||
385c98fc LW |
91 | /* |
92 | * A local singleton used by sched_clock and delay timer reads, which are | |
93 | * fast and stateless | |
94 | */ | |
e7bad212 LW |
95 | static struct fttmr010 *local_fttmr; |
96 | ||
97 | static inline struct fttmr010 *to_fttmr010(struct clock_event_device *evt) | |
98 | { | |
99 | return container_of(evt, struct fttmr010, clkevt); | |
100 | } | |
4750535b | 101 | |
c4779902 | 102 | static unsigned long fttmr010_read_current_timer_up(void) |
4750535b | 103 | { |
b589da8b | 104 | return readl(local_fttmr->base + TIMER2_COUNT); |
4750535b LW |
105 | } |
106 | ||
c4779902 | 107 | static unsigned long fttmr010_read_current_timer_down(void) |
740e237a LW |
108 | { |
109 | return ~readl(local_fttmr->base + TIMER2_COUNT); | |
110 | } | |
111 | ||
c4779902 | 112 | static u64 notrace fttmr010_read_sched_clock_up(void) |
385c98fc | 113 | { |
c4779902 | 114 | return fttmr010_read_current_timer_up(); |
385c98fc LW |
115 | } |
116 | ||
c4779902 | 117 | static u64 notrace fttmr010_read_sched_clock_down(void) |
385c98fc | 118 | { |
c4779902 | 119 | return fttmr010_read_current_timer_down(); |
385c98fc LW |
120 | } |
121 | ||
f5bf0ee4 | 122 | static int fttmr010_timer_set_next_event(unsigned long cycles, |
4750535b LW |
123 | struct clock_event_device *evt) |
124 | { | |
e7bad212 | 125 | struct fttmr010 *fttmr010 = to_fttmr010(evt); |
4750535b LW |
126 | u32 cr; |
127 | ||
ec14ba1e LW |
128 | /* Stop */ |
129 | cr = readl(fttmr010->base + TIMER_CR); | |
130 | cr &= ~fttmr010->t1_enable_val; | |
131 | writel(cr, fttmr010->base + TIMER_CR); | |
132 | ||
4451d3f5 TR |
133 | if (fttmr010->count_down) { |
134 | /* | |
135 | * ASPEED Timer Controller will load TIMER1_LOAD register | |
136 | * into TIMER1_COUNT register when the timer is re-enabled. | |
137 | */ | |
138 | writel(cycles, fttmr010->base + TIMER1_LOAD); | |
139 | } else { | |
140 | /* Setup the match register forward in time */ | |
141 | cr = readl(fttmr010->base + TIMER1_COUNT); | |
142 | writel(cr + cycles, fttmr010->base + TIMER1_MATCH1); | |
143 | } | |
ec14ba1e LW |
144 | |
145 | /* Start */ | |
146 | cr = readl(fttmr010->base + TIMER_CR); | |
147 | cr |= fttmr010->t1_enable_val; | |
148 | writel(cr, fttmr010->base + TIMER_CR); | |
4750535b LW |
149 | |
150 | return 0; | |
151 | } | |
152 | ||
f5bf0ee4 | 153 | static int fttmr010_timer_shutdown(struct clock_event_device *evt) |
4750535b | 154 | { |
e7bad212 LW |
155 | struct fttmr010 *fttmr010 = to_fttmr010(evt); |
156 | u32 cr; | |
157 | ||
ec14ba1e | 158 | /* Stop */ |
e7bad212 | 159 | cr = readl(fttmr010->base + TIMER_CR); |
ec14ba1e | 160 | cr &= ~fttmr010->t1_enable_val; |
e7bad212 LW |
161 | writel(cr, fttmr010->base + TIMER_CR); |
162 | ||
163 | return 0; | |
164 | } | |
165 | ||
166 | static int fttmr010_timer_set_oneshot(struct clock_event_device *evt) | |
167 | { | |
168 | struct fttmr010 *fttmr010 = to_fttmr010(evt); | |
4750535b LW |
169 | u32 cr; |
170 | ||
ec14ba1e | 171 | /* Stop */ |
e7bad212 | 172 | cr = readl(fttmr010->base + TIMER_CR); |
ec14ba1e | 173 | cr &= ~fttmr010->t1_enable_val; |
e7bad212 | 174 | writel(cr, fttmr010->base + TIMER_CR); |
4750535b | 175 | |
ec14ba1e | 176 | /* Setup counter start from 0 or ~0 */ |
e7bad212 | 177 | writel(0, fttmr010->base + TIMER1_COUNT); |
ec14ba1e LW |
178 | if (fttmr010->count_down) |
179 | writel(~0, fttmr010->base + TIMER1_LOAD); | |
180 | else | |
181 | writel(0, fttmr010->base + TIMER1_LOAD); | |
4750535b | 182 | |
e7bad212 LW |
183 | /* Enable interrupt */ |
184 | cr = readl(fttmr010->base + TIMER_INTR_MASK); | |
4750535b LW |
185 | cr &= ~(TIMER_1_INT_OVERFLOW | TIMER_1_INT_MATCH2); |
186 | cr |= TIMER_1_INT_MATCH1; | |
e7bad212 | 187 | writel(cr, fttmr010->base + TIMER_INTR_MASK); |
4750535b | 188 | |
4750535b LW |
189 | return 0; |
190 | } | |
191 | ||
f5bf0ee4 | 192 | static int fttmr010_timer_set_periodic(struct clock_event_device *evt) |
4750535b | 193 | { |
e7bad212 LW |
194 | struct fttmr010 *fttmr010 = to_fttmr010(evt); |
195 | u32 period = DIV_ROUND_CLOSEST(fttmr010->tick_rate, HZ); | |
4750535b LW |
196 | u32 cr; |
197 | ||
ec14ba1e | 198 | /* Stop */ |
e7bad212 | 199 | cr = readl(fttmr010->base + TIMER_CR); |
ec14ba1e | 200 | cr &= ~fttmr010->t1_enable_val; |
e7bad212 | 201 | writel(cr, fttmr010->base + TIMER_CR); |
4750535b | 202 | |
ec14ba1e LW |
203 | /* Setup timer to fire at 1/HZ intervals. */ |
204 | if (fttmr010->count_down) { | |
205 | writel(period, fttmr010->base + TIMER1_LOAD); | |
206 | writel(0, fttmr010->base + TIMER1_MATCH1); | |
207 | } else { | |
208 | cr = 0xffffffff - (period - 1); | |
209 | writel(cr, fttmr010->base + TIMER1_COUNT); | |
210 | writel(cr, fttmr010->base + TIMER1_LOAD); | |
211 | ||
212 | /* Enable interrupt on overflow */ | |
213 | cr = readl(fttmr010->base + TIMER_INTR_MASK); | |
214 | cr &= ~(TIMER_1_INT_MATCH1 | TIMER_1_INT_MATCH2); | |
215 | cr |= TIMER_1_INT_OVERFLOW; | |
216 | writel(cr, fttmr010->base + TIMER_INTR_MASK); | |
217 | } | |
4750535b LW |
218 | |
219 | /* Start the timer */ | |
e7bad212 | 220 | cr = readl(fttmr010->base + TIMER_CR); |
ec14ba1e | 221 | cr |= fttmr010->t1_enable_val; |
e7bad212 | 222 | writel(cr, fttmr010->base + TIMER_CR); |
4750535b LW |
223 | |
224 | return 0; | |
225 | } | |
226 | ||
4750535b LW |
227 | /* |
228 | * IRQ handler for the timer | |
229 | */ | |
f5bf0ee4 | 230 | static irqreturn_t fttmr010_timer_interrupt(int irq, void *dev_id) |
4750535b | 231 | { |
e7bad212 | 232 | struct clock_event_device *evt = dev_id; |
4750535b LW |
233 | |
234 | evt->event_handler(evt); | |
235 | return IRQ_HANDLED; | |
236 | } | |
237 | ||
ef89718a | 238 | static int __init fttmr010_common_init(struct device_node *np, bool is_aspeed) |
4750535b | 239 | { |
e7bad212 | 240 | struct fttmr010 *fttmr010; |
4750535b | 241 | int irq; |
dd98442e LW |
242 | struct clk *clk; |
243 | int ret; | |
ec14ba1e | 244 | u32 val; |
dd98442e LW |
245 | |
246 | /* | |
247 | * These implementations require a clock reference. | |
248 | * FIXME: we currently only support clocking using PCLK | |
249 | * and using EXTCLK is not supported in the driver. | |
250 | */ | |
251 | clk = of_clk_get_by_name(np, "PCLK"); | |
252 | if (IS_ERR(clk)) { | |
253 | pr_err("could not get PCLK\n"); | |
254 | return PTR_ERR(clk); | |
255 | } | |
256 | ret = clk_prepare_enable(clk); | |
257 | if (ret) { | |
258 | pr_err("failed to enable PCLK\n"); | |
259 | return ret; | |
260 | } | |
4750535b | 261 | |
e7bad212 LW |
262 | fttmr010 = kzalloc(sizeof(*fttmr010), GFP_KERNEL); |
263 | if (!fttmr010) { | |
264 | ret = -ENOMEM; | |
265 | goto out_disable_clock; | |
266 | } | |
267 | fttmr010->tick_rate = clk_get_rate(clk); | |
268 | ||
269 | fttmr010->base = of_iomap(np, 0); | |
270 | if (!fttmr010->base) { | |
1893428b | 271 | pr_err("Can't remap registers\n"); |
e7bad212 LW |
272 | ret = -ENXIO; |
273 | goto out_free; | |
4750535b LW |
274 | } |
275 | /* IRQ for timer 1 */ | |
276 | irq = irq_of_parse_and_map(np, 0); | |
277 | if (irq <= 0) { | |
1893428b | 278 | pr_err("Can't parse IRQ\n"); |
e7bad212 LW |
279 | ret = -EINVAL; |
280 | goto out_unmap; | |
4750535b LW |
281 | } |
282 | ||
ec14ba1e LW |
283 | /* |
284 | * The Aspeed AST2400 moves bits around in the control register, | |
285 | * otherwise it works the same. | |
286 | */ | |
ef89718a | 287 | if (is_aspeed) { |
ec14ba1e LW |
288 | fttmr010->t1_enable_val = TIMER_1_CR_ASPEED_ENABLE | |
289 | TIMER_1_CR_ASPEED_INT; | |
290 | /* Downward not available */ | |
291 | fttmr010->count_down = true; | |
292 | } else { | |
293 | fttmr010->t1_enable_val = TIMER_1_CR_ENABLE | TIMER_1_CR_INT; | |
294 | } | |
295 | ||
4750535b LW |
296 | /* |
297 | * Reset the interrupt mask and status | |
298 | */ | |
e7bad212 LW |
299 | writel(TIMER_INT_ALL_MASK, fttmr010->base + TIMER_INTR_MASK); |
300 | writel(0, fttmr010->base + TIMER_INTR_STATE); | |
ec14ba1e LW |
301 | |
302 | /* | |
303 | * Enable timer 1 count up, timer 2 count up, except on Aspeed, | |
304 | * where everything just counts down. | |
305 | */ | |
ef89718a | 306 | if (is_aspeed) |
ec14ba1e LW |
307 | val = TIMER_2_CR_ASPEED_ENABLE; |
308 | else { | |
309 | val = TIMER_2_CR_ENABLE; | |
310 | if (!fttmr010->count_down) | |
311 | val |= TIMER_1_CR_UPDOWN | TIMER_2_CR_UPDOWN; | |
312 | } | |
313 | writel(val, fttmr010->base + TIMER_CR); | |
4750535b LW |
314 | |
315 | /* | |
316 | * Setup free-running clocksource timer (interrupts | |
317 | * disabled.) | |
318 | */ | |
e7bad212 | 319 | local_fttmr = fttmr010; |
b589da8b | 320 | writel(0, fttmr010->base + TIMER2_COUNT); |
b589da8b LW |
321 | writel(0, fttmr010->base + TIMER2_MATCH1); |
322 | writel(0, fttmr010->base + TIMER2_MATCH2); | |
ec14ba1e LW |
323 | |
324 | if (fttmr010->count_down) { | |
325 | writel(~0, fttmr010->base + TIMER2_LOAD); | |
326 | clocksource_mmio_init(fttmr010->base + TIMER2_COUNT, | |
327 | "FTTMR010-TIMER2", | |
328 | fttmr010->tick_rate, | |
329 | 300, 32, clocksource_mmio_readl_down); | |
740e237a LW |
330 | sched_clock_register(fttmr010_read_sched_clock_down, 32, |
331 | fttmr010->tick_rate); | |
ec14ba1e LW |
332 | } else { |
333 | writel(0, fttmr010->base + TIMER2_LOAD); | |
334 | clocksource_mmio_init(fttmr010->base + TIMER2_COUNT, | |
335 | "FTTMR010-TIMER2", | |
336 | fttmr010->tick_rate, | |
337 | 300, 32, clocksource_mmio_readl_up); | |
740e237a LW |
338 | sched_clock_register(fttmr010_read_sched_clock_up, 32, |
339 | fttmr010->tick_rate); | |
ec14ba1e | 340 | } |
4750535b LW |
341 | |
342 | /* | |
e7bad212 | 343 | * Setup clockevent timer (interrupt-driven) on timer 1. |
4750535b | 344 | */ |
e7bad212 LW |
345 | writel(0, fttmr010->base + TIMER1_COUNT); |
346 | writel(0, fttmr010->base + TIMER1_LOAD); | |
347 | writel(0, fttmr010->base + TIMER1_MATCH1); | |
348 | writel(0, fttmr010->base + TIMER1_MATCH2); | |
349 | ret = request_irq(irq, fttmr010_timer_interrupt, IRQF_TIMER, | |
350 | "FTTMR010-TIMER1", &fttmr010->clkevt); | |
351 | if (ret) { | |
352 | pr_err("FTTMR010-TIMER1 no IRQ\n"); | |
353 | goto out_unmap; | |
354 | } | |
355 | ||
356 | fttmr010->clkevt.name = "FTTMR010-TIMER1"; | |
357 | /* Reasonably fast and accurate clock event */ | |
358 | fttmr010->clkevt.rating = 300; | |
359 | fttmr010->clkevt.features = CLOCK_EVT_FEAT_PERIODIC | | |
360 | CLOCK_EVT_FEAT_ONESHOT; | |
361 | fttmr010->clkevt.set_next_event = fttmr010_timer_set_next_event; | |
362 | fttmr010->clkevt.set_state_shutdown = fttmr010_timer_shutdown; | |
363 | fttmr010->clkevt.set_state_periodic = fttmr010_timer_set_periodic; | |
364 | fttmr010->clkevt.set_state_oneshot = fttmr010_timer_set_oneshot; | |
365 | fttmr010->clkevt.tick_resume = fttmr010_timer_shutdown; | |
366 | fttmr010->clkevt.cpumask = cpumask_of(0); | |
367 | fttmr010->clkevt.irq = irq; | |
368 | clockevents_config_and_register(&fttmr010->clkevt, | |
369 | fttmr010->tick_rate, | |
4750535b LW |
370 | 1, 0xffffffff); |
371 | ||
385c98fc LW |
372 | #ifdef CONFIG_ARM |
373 | /* Also use this timer for delays */ | |
374 | if (fttmr010->count_down) | |
375 | fttmr010->delay_timer.read_current_timer = | |
376 | fttmr010_read_current_timer_down; | |
377 | else | |
378 | fttmr010->delay_timer.read_current_timer = | |
379 | fttmr010_read_current_timer_up; | |
380 | fttmr010->delay_timer.freq = fttmr010->tick_rate; | |
381 | register_current_timer_delay(&fttmr010->delay_timer); | |
382 | #endif | |
383 | ||
4750535b | 384 | return 0; |
e7bad212 LW |
385 | |
386 | out_unmap: | |
387 | iounmap(fttmr010->base); | |
388 | out_free: | |
389 | kfree(fttmr010); | |
390 | out_disable_clock: | |
391 | clk_disable_unprepare(clk); | |
392 | ||
393 | return ret; | |
4750535b | 394 | } |
ef89718a DL |
395 | |
396 | static __init int aspeed_timer_init(struct device_node *np) | |
397 | { | |
398 | return fttmr010_common_init(np, true); | |
399 | } | |
400 | ||
401 | static __init int fttmr010_timer_init(struct device_node *np) | |
402 | { | |
403 | return fttmr010_common_init(np, false); | |
404 | } | |
405 | ||
17273395 DL |
406 | TIMER_OF_DECLARE(fttmr010, "faraday,fttmr010", fttmr010_timer_init); |
407 | TIMER_OF_DECLARE(gemini, "cortina,gemini-timer", fttmr010_timer_init); | |
408 | TIMER_OF_DECLARE(moxart, "moxa,moxart-timer", fttmr010_timer_init); | |
409 | TIMER_OF_DECLARE(ast2400, "aspeed,ast2400-timer", aspeed_timer_init); | |
410 | TIMER_OF_DECLARE(ast2500, "aspeed,ast2500-timer", aspeed_timer_init); |