1 // SPDX-License-Identifier: GPL-2.0-only
3  * Intel PPS signal Generator Driver
14 #include <linux/io-64-nonatomic-hi-lo.h>
39 #define MAGIC_CONST			(NSEC_PER_SEC - SAFE_TIME_NS)
54 	return readl(tio->base + offset);  in pps_tio_read()
59 	writel(value, tio->base + TIOCTL);  in pps_ctl_write()
64  * higher 32-bit followed by lower 32-bit
68 	hi_lo_writeq(value, tio->base + TIOCOMPV);  in pps_compv_write()
85 	tio->pps_gen->enabled = false;  in pps_tio_disable()
86 	tio->prev_count = 0;  in pps_tio_disable()
97 	tio->pps_gen->enabled = true;  in pps_tio_enable()
127 	pps_compv_write(art - ART_HW_DELAY_CYCLES, tio);  in pps_generate_next_pulse()
137 	guard(spinlock)(&tio->lock);  in hrtimer_callback()
144 	if (tio->prev_count && tio->prev_count == event_count)  in hrtimer_callback()
146 	tio->prev_count = event_count;  in hrtimer_callback()
151 	if (now - expires >= SAFE_TIME_NS)  in hrtimer_callback()
154 	tio->pps_gen->enabled = pps_generate_next_pulse(expires + SAFE_TIME_NS, tio);  in hrtimer_callback()
155 	if (!tio->pps_gen->enabled)  in hrtimer_callback()
162 	dev_err(tio->dev, "Event missed, Disabling Timed I/O");  in hrtimer_callback()
164 	pps_gen_event(tio->pps_gen, PPS_GEN_EVENT_MISSEDPULSE, NULL);  in hrtimer_callback()
170 	struct pps_tio *tio = container_of(pps_gen->info, struct pps_tio, gen_info);  in pps_tio_gen_enable()
173 		dev_err_once(tio->dev, "PPS cannot be used as clock is not related to ART");  in pps_tio_gen_enable()
174 		return -ENODEV;  in pps_tio_gen_enable()
177 	guard(spinlock_irqsave)(&tio->lock);  in pps_tio_gen_enable()
178 	if (enable && !pps_gen->enabled) {  in pps_tio_gen_enable()
180 		hrtimer_start(&tio->timer, first_event(tio), HRTIMER_MODE_ABS);  in pps_tio_gen_enable()
181 	} else if (!enable && pps_gen->enabled) {  in pps_tio_gen_enable()
182 		hrtimer_cancel(&tio->timer);  in pps_tio_gen_enable()
202 	struct device *dev = &pdev->dev;  in pps_gen_tio_probe()
208 		return -ENODEV;  in pps_gen_tio_probe()
213 		return -ENOMEM;  in pps_gen_tio_probe()
215 	tio->gen_info.use_system_clock = true;  in pps_gen_tio_probe()
216 	tio->gen_info.enable = pps_tio_gen_enable;  in pps_gen_tio_probe()
217 	tio->gen_info.get_time = pps_tio_get_time;  in pps_gen_tio_probe()
218 	tio->gen_info.owner = THIS_MODULE;  in pps_gen_tio_probe()
220 	tio->pps_gen = pps_gen_register_source(&tio->gen_info);  in pps_gen_tio_probe()
221 	if (IS_ERR(tio->pps_gen))  in pps_gen_tio_probe()
222 		return PTR_ERR(tio->pps_gen);  in pps_gen_tio_probe()
224 	tio->dev = dev;  in pps_gen_tio_probe()
225 	tio->base = devm_platform_ioremap_resource(pdev, 0);  in pps_gen_tio_probe()
226 	if (IS_ERR(tio->base))  in pps_gen_tio_probe()
227 		return PTR_ERR(tio->base);  in pps_gen_tio_probe()
230 	hrtimer_setup(&tio->timer, hrtimer_callback, CLOCK_REALTIME,  in pps_gen_tio_probe()
232 	spin_lock_init(&tio->lock);  in pps_gen_tio_probe()
242 	hrtimer_cancel(&tio->timer);  in pps_gen_tio_remove()
244 	pps_gen_unregister_source(tio->pps_gen);  in pps_gen_tio_remove()
260 		.name                   = "intel-pps-gen-tio",
271 MODULE_DESCRIPTION("Intel PMC Time-Aware IO Generator Driver");