xref: /openbmc/linux/drivers/devfreq/rk3399_dmc.c (revision de2bdb3d)
1 /*
2  * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd.
3  * Author: Lin Huang <hl@rock-chips.com>
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  */
14 
15 #include <linux/arm-smccc.h>
16 #include <linux/clk.h>
17 #include <linux/delay.h>
18 #include <linux/devfreq.h>
19 #include <linux/devfreq-event.h>
20 #include <linux/interrupt.h>
21 #include <linux/module.h>
22 #include <linux/of.h>
23 #include <linux/platform_device.h>
24 #include <linux/pm_opp.h>
25 #include <linux/regulator/consumer.h>
26 #include <linux/rwsem.h>
27 #include <linux/suspend.h>
28 
29 #include <soc/rockchip/rockchip_sip.h>
30 
31 struct dram_timing {
32 	unsigned int ddr3_speed_bin;
33 	unsigned int pd_idle;
34 	unsigned int sr_idle;
35 	unsigned int sr_mc_gate_idle;
36 	unsigned int srpd_lite_idle;
37 	unsigned int standby_idle;
38 	unsigned int auto_pd_dis_freq;
39 	unsigned int dram_dll_dis_freq;
40 	unsigned int phy_dll_dis_freq;
41 	unsigned int ddr3_odt_dis_freq;
42 	unsigned int ddr3_drv;
43 	unsigned int ddr3_odt;
44 	unsigned int phy_ddr3_ca_drv;
45 	unsigned int phy_ddr3_dq_drv;
46 	unsigned int phy_ddr3_odt;
47 	unsigned int lpddr3_odt_dis_freq;
48 	unsigned int lpddr3_drv;
49 	unsigned int lpddr3_odt;
50 	unsigned int phy_lpddr3_ca_drv;
51 	unsigned int phy_lpddr3_dq_drv;
52 	unsigned int phy_lpddr3_odt;
53 	unsigned int lpddr4_odt_dis_freq;
54 	unsigned int lpddr4_drv;
55 	unsigned int lpddr4_dq_odt;
56 	unsigned int lpddr4_ca_odt;
57 	unsigned int phy_lpddr4_ca_drv;
58 	unsigned int phy_lpddr4_ck_cs_drv;
59 	unsigned int phy_lpddr4_dq_drv;
60 	unsigned int phy_lpddr4_odt;
61 };
62 
63 struct rk3399_dmcfreq {
64 	struct device *dev;
65 	struct devfreq *devfreq;
66 	struct devfreq_simple_ondemand_data ondemand_data;
67 	struct clk *dmc_clk;
68 	struct devfreq_event_dev *edev;
69 	struct mutex lock;
70 	struct dram_timing timing;
71 
72 	/*
73 	 * DDR Converser of Frequency (DCF) is used to implement DDR frequency
74 	 * conversion without the participation of CPU, we will implement and
75 	 * control it in arm trust firmware.
76 	 */
77 	wait_queue_head_t	wait_dcf_queue;
78 	int irq;
79 	int wait_dcf_flag;
80 	struct regulator *vdd_center;
81 	unsigned long rate, target_rate;
82 	unsigned long volt, target_volt;
83 	struct dev_pm_opp *curr_opp;
84 };
85 
86 static int rk3399_dmcfreq_target(struct device *dev, unsigned long *freq,
87 				 u32 flags)
88 {
89 	struct rk3399_dmcfreq *dmcfreq = dev_get_drvdata(dev);
90 	struct dev_pm_opp *opp;
91 	unsigned long old_clk_rate = dmcfreq->rate;
92 	unsigned long target_volt, target_rate;
93 	int err;
94 
95 	rcu_read_lock();
96 	opp = devfreq_recommended_opp(dev, freq, flags);
97 	if (IS_ERR(opp)) {
98 		rcu_read_unlock();
99 		return PTR_ERR(opp);
100 	}
101 
102 	target_rate = dev_pm_opp_get_freq(opp);
103 	target_volt = dev_pm_opp_get_voltage(opp);
104 
105 	dmcfreq->rate = dev_pm_opp_get_freq(dmcfreq->curr_opp);
106 	dmcfreq->volt = dev_pm_opp_get_voltage(dmcfreq->curr_opp);
107 
108 	rcu_read_unlock();
109 
110 	if (dmcfreq->rate == target_rate)
111 		return 0;
112 
113 	mutex_lock(&dmcfreq->lock);
114 
115 	/*
116 	 * If frequency scaling from low to high, adjust voltage first.
117 	 * If frequency scaling from high to low, adjust frequency first.
118 	 */
119 	if (old_clk_rate < target_rate) {
120 		err = regulator_set_voltage(dmcfreq->vdd_center, target_volt,
121 					    target_volt);
122 		if (err) {
123 			dev_err(dev, "Cannot to set voltage %lu uV\n",
124 				target_volt);
125 			goto out;
126 		}
127 	}
128 	dmcfreq->wait_dcf_flag = 1;
129 
130 	err = clk_set_rate(dmcfreq->dmc_clk, target_rate);
131 	if (err) {
132 		dev_err(dev, "Cannot to set frequency %lu (%d)\n",
133 			target_rate, err);
134 		regulator_set_voltage(dmcfreq->vdd_center, dmcfreq->volt,
135 				      dmcfreq->volt);
136 		goto out;
137 	}
138 
139 	/*
140 	 * Wait until bcf irq happen, it means freq scaling finish in
141 	 * arm trust firmware, use 100ms as timeout time.
142 	 */
143 	if (!wait_event_timeout(dmcfreq->wait_dcf_queue,
144 				!dmcfreq->wait_dcf_flag, HZ / 10))
145 		dev_warn(dev, "Timeout waiting for dcf interrupt\n");
146 
147 	/*
148 	 * Check the dpll rate,
149 	 * There only two result we will get,
150 	 * 1. Ddr frequency scaling fail, we still get the old rate.
151 	 * 2. Ddr frequency scaling sucessful, we get the rate we set.
152 	 */
153 	dmcfreq->rate = clk_get_rate(dmcfreq->dmc_clk);
154 
155 	/* If get the incorrect rate, set voltage to old value. */
156 	if (dmcfreq->rate != target_rate) {
157 		dev_err(dev, "Get wrong ddr frequency, Request frequency %lu,\
158 			Current frequency %lu\n", target_rate, dmcfreq->rate);
159 		regulator_set_voltage(dmcfreq->vdd_center, dmcfreq->volt,
160 				      dmcfreq->volt);
161 		goto out;
162 	} else if (old_clk_rate > target_rate)
163 		err = regulator_set_voltage(dmcfreq->vdd_center, target_volt,
164 					    target_volt);
165 	if (err)
166 		dev_err(dev, "Cannot to set vol %lu uV\n", target_volt);
167 
168 	dmcfreq->curr_opp = opp;
169 out:
170 	mutex_unlock(&dmcfreq->lock);
171 	return err;
172 }
173 
174 static int rk3399_dmcfreq_get_dev_status(struct device *dev,
175 					 struct devfreq_dev_status *stat)
176 {
177 	struct rk3399_dmcfreq *dmcfreq = dev_get_drvdata(dev);
178 	struct devfreq_event_data edata;
179 	int ret = 0;
180 
181 	ret = devfreq_event_get_event(dmcfreq->edev, &edata);
182 	if (ret < 0)
183 		return ret;
184 
185 	stat->current_frequency = dmcfreq->rate;
186 	stat->busy_time = edata.load_count;
187 	stat->total_time = edata.total_count;
188 
189 	return ret;
190 }
191 
192 static int rk3399_dmcfreq_get_cur_freq(struct device *dev, unsigned long *freq)
193 {
194 	struct rk3399_dmcfreq *dmcfreq = dev_get_drvdata(dev);
195 
196 	*freq = dmcfreq->rate;
197 
198 	return 0;
199 }
200 
201 static struct devfreq_dev_profile rk3399_devfreq_dmc_profile = {
202 	.polling_ms	= 200,
203 	.target		= rk3399_dmcfreq_target,
204 	.get_dev_status	= rk3399_dmcfreq_get_dev_status,
205 	.get_cur_freq	= rk3399_dmcfreq_get_cur_freq,
206 };
207 
208 static __maybe_unused int rk3399_dmcfreq_suspend(struct device *dev)
209 {
210 	struct rk3399_dmcfreq *dmcfreq = dev_get_drvdata(dev);
211 	int ret = 0;
212 
213 	ret = devfreq_event_disable_edev(dmcfreq->edev);
214 	if (ret < 0) {
215 		dev_err(dev, "failed to disable the devfreq-event devices\n");
216 		return ret;
217 	}
218 
219 	ret = devfreq_suspend_device(dmcfreq->devfreq);
220 	if (ret < 0) {
221 		dev_err(dev, "failed to suspend the devfreq devices\n");
222 		return ret;
223 	}
224 
225 	return 0;
226 }
227 
228 static __maybe_unused int rk3399_dmcfreq_resume(struct device *dev)
229 {
230 	struct rk3399_dmcfreq *dmcfreq = dev_get_drvdata(dev);
231 	int ret = 0;
232 
233 	ret = devfreq_event_enable_edev(dmcfreq->edev);
234 	if (ret < 0) {
235 		dev_err(dev, "failed to enable the devfreq-event devices\n");
236 		return ret;
237 	}
238 
239 	ret = devfreq_resume_device(dmcfreq->devfreq);
240 	if (ret < 0) {
241 		dev_err(dev, "failed to resume the devfreq devices\n");
242 		return ret;
243 	}
244 	return ret;
245 }
246 
247 static SIMPLE_DEV_PM_OPS(rk3399_dmcfreq_pm, rk3399_dmcfreq_suspend,
248 			 rk3399_dmcfreq_resume);
249 
250 static irqreturn_t rk3399_dmc_irq(int irq, void *dev_id)
251 {
252 	struct rk3399_dmcfreq *dmcfreq = dev_id;
253 	struct arm_smccc_res res;
254 
255 	dmcfreq->wait_dcf_flag = 0;
256 	wake_up(&dmcfreq->wait_dcf_queue);
257 
258 	/* Clear the DCF interrupt */
259 	arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, 0, 0,
260 		      ROCKCHIP_SIP_CONFIG_DRAM_CLR_IRQ,
261 		      0, 0, 0, 0, &res);
262 
263 	return IRQ_HANDLED;
264 }
265 
266 static int of_get_ddr_timings(struct dram_timing *timing,
267 			      struct device_node *np)
268 {
269 	int ret = 0;
270 
271 	ret = of_property_read_u32(np, "rockchip,ddr3_speed_bin",
272 				   &timing->ddr3_speed_bin);
273 	ret |= of_property_read_u32(np, "rockchip,pd_idle",
274 				    &timing->pd_idle);
275 	ret |= of_property_read_u32(np, "rockchip,sr_idle",
276 				    &timing->sr_idle);
277 	ret |= of_property_read_u32(np, "rockchip,sr_mc_gate_idle",
278 				    &timing->sr_mc_gate_idle);
279 	ret |= of_property_read_u32(np, "rockchip,srpd_lite_idle",
280 				    &timing->srpd_lite_idle);
281 	ret |= of_property_read_u32(np, "rockchip,standby_idle",
282 				    &timing->standby_idle);
283 	ret |= of_property_read_u32(np, "rockchip,auto_pd_dis_freq",
284 				    &timing->auto_pd_dis_freq);
285 	ret |= of_property_read_u32(np, "rockchip,dram_dll_dis_freq",
286 				    &timing->dram_dll_dis_freq);
287 	ret |= of_property_read_u32(np, "rockchip,phy_dll_dis_freq",
288 				    &timing->phy_dll_dis_freq);
289 	ret |= of_property_read_u32(np, "rockchip,ddr3_odt_dis_freq",
290 				    &timing->ddr3_odt_dis_freq);
291 	ret |= of_property_read_u32(np, "rockchip,ddr3_drv",
292 				    &timing->ddr3_drv);
293 	ret |= of_property_read_u32(np, "rockchip,ddr3_odt",
294 				    &timing->ddr3_odt);
295 	ret |= of_property_read_u32(np, "rockchip,phy_ddr3_ca_drv",
296 				    &timing->phy_ddr3_ca_drv);
297 	ret |= of_property_read_u32(np, "rockchip,phy_ddr3_dq_drv",
298 				    &timing->phy_ddr3_dq_drv);
299 	ret |= of_property_read_u32(np, "rockchip,phy_ddr3_odt",
300 				    &timing->phy_ddr3_odt);
301 	ret |= of_property_read_u32(np, "rockchip,lpddr3_odt_dis_freq",
302 				    &timing->lpddr3_odt_dis_freq);
303 	ret |= of_property_read_u32(np, "rockchip,lpddr3_drv",
304 				    &timing->lpddr3_drv);
305 	ret |= of_property_read_u32(np, "rockchip,lpddr3_odt",
306 				    &timing->lpddr3_odt);
307 	ret |= of_property_read_u32(np, "rockchip,phy_lpddr3_ca_drv",
308 				    &timing->phy_lpddr3_ca_drv);
309 	ret |= of_property_read_u32(np, "rockchip,phy_lpddr3_dq_drv",
310 				    &timing->phy_lpddr3_dq_drv);
311 	ret |= of_property_read_u32(np, "rockchip,phy_lpddr3_odt",
312 				    &timing->phy_lpddr3_odt);
313 	ret |= of_property_read_u32(np, "rockchip,lpddr4_odt_dis_freq",
314 				    &timing->lpddr4_odt_dis_freq);
315 	ret |= of_property_read_u32(np, "rockchip,lpddr4_drv",
316 				    &timing->lpddr4_drv);
317 	ret |= of_property_read_u32(np, "rockchip,lpddr4_dq_odt",
318 				    &timing->lpddr4_dq_odt);
319 	ret |= of_property_read_u32(np, "rockchip,lpddr4_ca_odt",
320 				    &timing->lpddr4_ca_odt);
321 	ret |= of_property_read_u32(np, "rockchip,phy_lpddr4_ca_drv",
322 				    &timing->phy_lpddr4_ca_drv);
323 	ret |= of_property_read_u32(np, "rockchip,phy_lpddr4_ck_cs_drv",
324 				    &timing->phy_lpddr4_ck_cs_drv);
325 	ret |= of_property_read_u32(np, "rockchip,phy_lpddr4_dq_drv",
326 				    &timing->phy_lpddr4_dq_drv);
327 	ret |= of_property_read_u32(np, "rockchip,phy_lpddr4_odt",
328 				    &timing->phy_lpddr4_odt);
329 
330 	return ret;
331 }
332 
333 static int rk3399_dmcfreq_probe(struct platform_device *pdev)
334 {
335 	struct arm_smccc_res res;
336 	struct device *dev = &pdev->dev;
337 	struct device_node *np = pdev->dev.of_node;
338 	struct rk3399_dmcfreq *data;
339 	int ret, irq, index, size;
340 	uint32_t *timing;
341 	struct dev_pm_opp *opp;
342 
343 	irq = platform_get_irq(pdev, 0);
344 	if (irq < 0) {
345 		dev_err(&pdev->dev, "Cannot get the dmc interrupt resource\n");
346 		return -EINVAL;
347 	}
348 	data = devm_kzalloc(dev, sizeof(struct rk3399_dmcfreq), GFP_KERNEL);
349 	if (!data)
350 		return -ENOMEM;
351 
352 	mutex_init(&data->lock);
353 
354 	data->vdd_center = devm_regulator_get(dev, "center");
355 	if (IS_ERR(data->vdd_center)) {
356 		dev_err(dev, "Cannot get the regulator \"center\"\n");
357 		return PTR_ERR(data->vdd_center);
358 	}
359 
360 	data->dmc_clk = devm_clk_get(dev, "dmc_clk");
361 	if (IS_ERR(data->dmc_clk)) {
362 		dev_err(dev, "Cannot get the clk dmc_clk\n");
363 		return PTR_ERR(data->dmc_clk);
364 	};
365 
366 	data->irq = irq;
367 	ret = devm_request_irq(dev, irq, rk3399_dmc_irq, 0,
368 			       dev_name(dev), data);
369 	if (ret) {
370 		dev_err(dev, "Failed to request dmc irq: %d\n", ret);
371 		return ret;
372 	}
373 
374 	init_waitqueue_head(&data->wait_dcf_queue);
375 	data->wait_dcf_flag = 0;
376 
377 	data->edev = devfreq_event_get_edev_by_phandle(dev, 0);
378 	if (IS_ERR(data->edev))
379 		return -EPROBE_DEFER;
380 
381 	ret = devfreq_event_enable_edev(data->edev);
382 	if (ret < 0) {
383 		dev_err(dev, "failed to enable devfreq-event devices\n");
384 		return ret;
385 	}
386 
387 	/*
388 	 * Get dram timing and pass it to arm trust firmware,
389 	 * the dram drvier in arm trust firmware will get these
390 	 * timing and to do dram initial.
391 	 */
392 	if (!of_get_ddr_timings(&data->timing, np)) {
393 		timing = &data->timing.ddr3_speed_bin;
394 		size = sizeof(struct dram_timing) / 4;
395 		for (index = 0; index < size; index++) {
396 			arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, *timing++, index,
397 				      ROCKCHIP_SIP_CONFIG_DRAM_SET_PARAM,
398 				      0, 0, 0, 0, &res);
399 			if (res.a0) {
400 				dev_err(dev, "Failed to set dram param: %ld\n",
401 					res.a0);
402 				return -EINVAL;
403 			}
404 		}
405 	}
406 
407 	arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, 0, 0,
408 		      ROCKCHIP_SIP_CONFIG_DRAM_INIT,
409 		      0, 0, 0, 0, &res);
410 
411 	/*
412 	 * We add a devfreq driver to our parent since it has a device tree node
413 	 * with operating points.
414 	 */
415 	if (dev_pm_opp_of_add_table(dev)) {
416 		dev_err(dev, "Invalid operating-points in device tree.\n");
417 		rcu_read_unlock();
418 		return -EINVAL;
419 	}
420 
421 	of_property_read_u32(np, "upthreshold",
422 			     &data->ondemand_data.upthreshold);
423 	of_property_read_u32(np, "downdifferential",
424 			     &data->ondemand_data.downdifferential);
425 
426 	data->rate = clk_get_rate(data->dmc_clk);
427 
428 	rcu_read_lock();
429 	opp = devfreq_recommended_opp(dev, &data->rate, 0);
430 	if (IS_ERR(opp)) {
431 		rcu_read_unlock();
432 		return PTR_ERR(opp);
433 	}
434 	rcu_read_unlock();
435 	data->curr_opp = opp;
436 
437 	rk3399_devfreq_dmc_profile.initial_freq = data->rate;
438 
439 	data->devfreq = devfreq_add_device(dev,
440 					   &rk3399_devfreq_dmc_profile,
441 					   "simple_ondemand",
442 					   &data->ondemand_data);
443 	if (IS_ERR(data->devfreq))
444 		return PTR_ERR(data->devfreq);
445 	devm_devfreq_register_opp_notifier(dev, data->devfreq);
446 
447 	data->dev = dev;
448 	platform_set_drvdata(pdev, data);
449 
450 	return 0;
451 }
452 
453 static const struct of_device_id rk3399dmc_devfreq_of_match[] = {
454 	{ .compatible = "rockchip,rk3399-dmc" },
455 	{ },
456 };
457 
458 static struct platform_driver rk3399_dmcfreq_driver = {
459 	.probe	= rk3399_dmcfreq_probe,
460 	.driver = {
461 		.name	= "rk3399-dmc-freq",
462 		.pm	= &rk3399_dmcfreq_pm,
463 		.of_match_table = rk3399dmc_devfreq_of_match,
464 	},
465 };
466 module_platform_driver(rk3399_dmcfreq_driver);
467 
468 MODULE_LICENSE("GPL v2");
469 MODULE_AUTHOR("Lin Huang <hl@rock-chips.com>");
470 MODULE_DESCRIPTION("RK3399 dmcfreq driver with devfreq framework");
471