1 // SPDX-License-Identifier: GPL-2.0
3 /* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
4  * Copyright (C) 2018-2020 Linaro Ltd.
13 #include "ipa.h"
18  * DOC: IPA Clocking
20  * The "IPA Clock" manages both the IPA core clock and the interconnects
21  * (buses) the IPA depends on as a single logical entity.  A reference count
23  * Transitions of that count from 0 to 1 result in the clock and interconnects
24  * being enabled, and transitions of the count from 1 to 0 cause them to be
25  * disabled.  We currently operate the core clock at a fixed clock rate, and
26  * all buses at a fixed average and peak bandwidth.  As more advanced IPA
27  * features are enabled, we can make better use of clock and bus scaling.
29  * An IPA clock reference must be held for any access to IPA hardware.
45  * struct ipa_clock - IPA clocking information
47  * @mutex:		Protects clock enable/disable
48  * @core:		IPA core clock
55 	struct mutex mutex; /* protects clock enable/disable */
75 /* Initialize interconnects required for IPA operation */
76 static int ipa_interconnect_init(struct ipa_clock *clock, struct device *dev)  in ipa_interconnect_init()  argument
83 	clock->memory_path = path;  in ipa_interconnect_init()
88 	clock->imem_path = path;  in ipa_interconnect_init()
93 	clock->config_path = path;  in ipa_interconnect_init()
98 	icc_put(clock->imem_path);  in ipa_interconnect_init()
100 	icc_put(clock->memory_path);  in ipa_interconnect_init()
106 static void ipa_interconnect_exit(struct ipa_clock *clock)  in ipa_interconnect_exit()  argument
108 	icc_put(clock->config_path);  in ipa_interconnect_exit()
109 	icc_put(clock->imem_path);  in ipa_interconnect_exit()
110 	icc_put(clock->memory_path);  in ipa_interconnect_exit()
114 static int ipa_interconnect_enable(struct ipa *ipa)  in ipa_interconnect_enable()  argument
116 	struct ipa_clock *clock = ipa->clock;  in ipa_interconnect_enable()  local
119 	ret = icc_set_bw(clock->memory_path, IPA_MEMORY_AVG, IPA_MEMORY_PEAK);  in ipa_interconnect_enable()
123 	ret = icc_set_bw(clock->imem_path, IPA_IMEM_AVG, IPA_IMEM_PEAK);  in ipa_interconnect_enable()
127 	ret = icc_set_bw(clock->config_path, IPA_CONFIG_AVG, IPA_CONFIG_PEAK);  in ipa_interconnect_enable()
134 	(void)icc_set_bw(clock->imem_path, 0, 0);  in ipa_interconnect_enable()
136 	(void)icc_set_bw(clock->memory_path, 0, 0);  in ipa_interconnect_enable()
142 static int ipa_interconnect_disable(struct ipa *ipa)  in ipa_interconnect_disable()  argument
144 	struct ipa_clock *clock = ipa->clock;  in ipa_interconnect_disable()  local
147 	ret = icc_set_bw(clock->memory_path, 0, 0);  in ipa_interconnect_disable()
151 	ret = icc_set_bw(clock->imem_path, 0, 0);  in ipa_interconnect_disable()
155 	ret = icc_set_bw(clock->config_path, 0, 0);  in ipa_interconnect_disable()
162 	(void)icc_set_bw(clock->imem_path, IPA_IMEM_AVG, IPA_IMEM_PEAK);  in ipa_interconnect_disable()
164 	(void)icc_set_bw(clock->memory_path, IPA_MEMORY_AVG, IPA_MEMORY_PEAK);  in ipa_interconnect_disable()
169 /* Turn on IPA clocks, including interconnects */
170 static int ipa_clock_enable(struct ipa *ipa)  in ipa_clock_enable()  argument
174 	ret = ipa_interconnect_enable(ipa);  in ipa_clock_enable()
178 	ret = clk_prepare_enable(ipa->clock->core);  in ipa_clock_enable()
180 		ipa_interconnect_disable(ipa);  in ipa_clock_enable()
186 static void ipa_clock_disable(struct ipa *ipa)  in ipa_clock_disable()  argument
188 	clk_disable_unprepare(ipa->clock->core);  in ipa_clock_disable()
189 	(void)ipa_interconnect_disable(ipa);  in ipa_clock_disable()
192 /* Get an IPA clock reference, but only if the reference count is
193  * already non-zero.  Returns true if the additional reference was
196 bool ipa_clock_get_additional(struct ipa *ipa)  in ipa_clock_get_additional()  argument
198 	return refcount_inc_not_zero(&ipa->clock->count);  in ipa_clock_get_additional()
201 /* Get an IPA clock reference.  If the reference count is non-zero, it is
203  * under protection of the mutex, and if appropriate the IPA clock
204  * is enabled.
207  * after the clock is running and endpoints are resumed.
209 void ipa_clock_get(struct ipa *ipa)  in ipa_clock_get()  argument
211 	struct ipa_clock *clock = ipa->clock;  in ipa_clock_get()  local
214 	/* If the clock is running, just bump the reference count */  in ipa_clock_get()
215 	if (ipa_clock_get_additional(ipa))  in ipa_clock_get()
219 	mutex_lock(&clock->mutex);  in ipa_clock_get()
222 	if (ipa_clock_get_additional(ipa))  in ipa_clock_get()
225 	ret = ipa_clock_enable(ipa);  in ipa_clock_get()
227 		dev_err(&ipa->pdev->dev, "error %d enabling IPA clock\n", ret);  in ipa_clock_get()
231 	refcount_set(&clock->count, 1);  in ipa_clock_get()
234 	mutex_unlock(&clock->mutex);  in ipa_clock_get()
237 /* Attempt to remove an IPA clock reference.  If this represents the
238  * last reference, disable the IPA clock under protection of the mutex.
240 void ipa_clock_put(struct ipa *ipa)  in ipa_clock_put()  argument
242 	struct ipa_clock *clock = ipa->clock;  in ipa_clock_put()  local
245 	if (!refcount_dec_and_mutex_lock(&clock->count, &clock->mutex))  in ipa_clock_put()
248 	ipa_clock_disable(ipa);  in ipa_clock_put()
250 	mutex_unlock(&clock->mutex);  in ipa_clock_put()
253 /* Return the current IPA core clock rate */
254 u32 ipa_clock_rate(struct ipa *ipa)  in ipa_clock_rate()  argument
256 	return ipa->clock ? (u32)clk_get_rate(ipa->clock->core) : 0;  in ipa_clock_rate()
259 /* Initialize IPA clocking */
262 	struct ipa_clock *clock;  in ipa_clock_init()  local
268 		dev_err(dev, "error %ld getting core clock\n", PTR_ERR(clk));  in ipa_clock_init()
274 		dev_err(dev, "error %d setting core clock rate to %lu\n",  in ipa_clock_init()
279 	clock = kzalloc(sizeof(*clock), GFP_KERNEL);  in ipa_clock_init()
280 	if (!clock) {  in ipa_clock_init()
281 		ret = -ENOMEM;  in ipa_clock_init()
284 	clock->core = clk;  in ipa_clock_init()
286 	ret = ipa_interconnect_init(clock, dev);  in ipa_clock_init()
290 	mutex_init(&clock->mutex);  in ipa_clock_init()
291 	refcount_set(&clock->count, 0);  in ipa_clock_init()
293 	return clock;  in ipa_clock_init()
296 	kfree(clock);  in ipa_clock_init()
304 void ipa_clock_exit(struct ipa_clock *clock)  in ipa_clock_exit()  argument
306 	struct clk *clk = clock->core;  in ipa_clock_exit()
308 	WARN_ON(refcount_read(&clock->count) != 0);  in ipa_clock_exit()
309 	mutex_destroy(&clock->mutex);  in ipa_clock_exit()
310 	ipa_interconnect_exit(clock);  in ipa_clock_exit()
311 	kfree(clock);  in ipa_clock_exit()