1 // SPDX-License-Identifier: GPL-2.0
3  * Copyright (c) 2015-2020, NVIDIA CORPORATION.  All rights reserved.
8 #include <linux/clk-provider.h>
57 	value = readl_relaxed(emc->regs + CLK_SOURCE_EMC);  in tegra210_clk_emc_get_parent()
70 	 * CCF assumes that neither the parent nor its rate will change during  in tegra210_clk_emc_recalc_rate()
71 	 * ->set_rate(), so the parent rate passed in here was cached from the  in tegra210_clk_emc_recalc_rate()
72 	 * parent before the ->set_rate() call.  in tegra210_clk_emc_recalc_rate()
75 	 * the parent and/or parent rate have changed as part of the EMC rate  in tegra210_clk_emc_recalc_rate()
76 	 * change sequence. Fix this by overriding the parent clock with what  in tegra210_clk_emc_recalc_rate()
77 	 * we know to be the correct value after the rate change.  in tegra210_clk_emc_recalc_rate()
81 	value = readl_relaxed(emc->regs + CLK_SOURCE_EMC);  in tegra210_clk_emc_recalc_rate()
89 static long tegra210_clk_emc_round_rate(struct clk_hw *hw, unsigned long rate,  in tegra210_clk_emc_round_rate()  argument
93 	struct tegra210_clk_emc_provider *provider = emc->provider;  in tegra210_clk_emc_round_rate()
96 	if (!provider || !provider->configs || provider->num_configs == 0)  in tegra210_clk_emc_round_rate()
99 	for (i = 0; i < provider->num_configs; i++) {  in tegra210_clk_emc_round_rate()
100 		if (provider->configs[i].rate >= rate)  in tegra210_clk_emc_round_rate()
101 			return provider->configs[i].rate;  in tegra210_clk_emc_round_rate()
104 	return provider->configs[i - 1].rate;  in tegra210_clk_emc_round_rate()
110 	struct clk_hw *parent = clk_hw_get_parent_by_index(&emc->hw, index);  in tegra210_clk_emc_find_parent()  local
111 	const char *name = clk_hw_get_name(parent);  in tegra210_clk_emc_find_parent()
118 static int tegra210_clk_emc_set_rate(struct clk_hw *hw, unsigned long rate,  in tegra210_clk_emc_set_rate()  argument
122 	struct tegra210_clk_emc_provider *provider = emc->provider;  in tegra210_clk_emc_set_rate()
124 	struct device *dev = provider->dev;  in tegra210_clk_emc_set_rate()
125 	struct clk_hw *old, *new, *parent;  in tegra210_clk_emc_set_rate()  local
131 	if (!provider->configs || provider->num_configs == 0)  in tegra210_clk_emc_set_rate()
132 		return -EINVAL;  in tegra210_clk_emc_set_rate()
134 	for (i = 0; i < provider->num_configs; i++) {  in tegra210_clk_emc_set_rate()
135 		if (provider->configs[i].rate >= rate) {  in tegra210_clk_emc_set_rate()
136 			config = &provider->configs[i];  in tegra210_clk_emc_set_rate()
141 	if (i == provider->num_configs)  in tegra210_clk_emc_set_rate()
142 		config = &provider->configs[i - 1];  in tegra210_clk_emc_set_rate()
145 	new_idx = FIELD_GET(CLK_SOURCE_EMC_2X_CLK_SRC, config->value);  in tegra210_clk_emc_set_rate()
150 	/* if the rate has changed... */  in tegra210_clk_emc_set_rate()
151 	if (config->parent_rate != clk_hw_get_rate(old)) {  in tegra210_clk_emc_set_rate()
178 				return -EINVAL;  in tegra210_clk_emc_set_rate()
184 		parent = new;  in tegra210_clk_emc_set_rate()
187 		parent = old;  in tegra210_clk_emc_set_rate()
193 		dev_err(dev, "failed to get parent clock for index %u: %d\n",  in tegra210_clk_emc_set_rate()
198 	/* set the new parent clock to the required rate */  in tegra210_clk_emc_set_rate()
199 	if (clk_get_rate(clk) != config->parent_rate) {  in tegra210_clk_emc_set_rate()
200 		err = clk_set_rate(clk, config->parent_rate);  in tegra210_clk_emc_set_rate()
202 			dev_err(dev, "failed to set rate %lu Hz for %pC: %d\n",  in tegra210_clk_emc_set_rate()
203 				config->parent_rate, clk, err);  in tegra210_clk_emc_set_rate()
208 	/* enable the new parent clock */  in tegra210_clk_emc_set_rate()
209 	if (parent != old) {  in tegra210_clk_emc_set_rate()
212 			dev_err(dev, "failed to enable parent clock %pC: %d\n",  in tegra210_clk_emc_set_rate()
218 	/* update the EMC source configuration to reflect the new parent */  in tegra210_clk_emc_set_rate()
219 	config->value &= ~CLK_SOURCE_EMC_2X_CLK_SRC;  in tegra210_clk_emc_set_rate()
220 	config->value |= FIELD_PREP(CLK_SOURCE_EMC_2X_CLK_SRC, index);  in tegra210_clk_emc_set_rate()
223 	 * Finally, switch the EMC programming with both old and new parent  in tegra210_clk_emc_set_rate()
226 	err = provider->set_rate(dev, config);  in tegra210_clk_emc_set_rate()
228 		dev_err(dev, "failed to set EMC rate to %lu Hz: %d\n", rate,  in tegra210_clk_emc_set_rate()
233 		 * longer need the new parent to be enabled.  in tegra210_clk_emc_set_rate()
235 		if (parent != old)  in tegra210_clk_emc_set_rate()
241 	/* reparent to new parent clock and disable the old parent clock */  in tegra210_clk_emc_set_rate()
242 	if (parent != old) {  in tegra210_clk_emc_set_rate()
247 				"failed to get parent clock for index %u: %d\n",  in tegra210_clk_emc_set_rate()
252 		clk_hw_reparent(hw, parent);  in tegra210_clk_emc_set_rate()
275 		return ERR_PTR(-ENOMEM);  in tegra210_clk_register_emc()
277 	emc->regs = regs;  in tegra210_clk_register_emc()
284 	emc->hw.init = &init;  in tegra210_clk_register_emc()
286 	clk = clk_register(NULL, &emc->hw);  in tegra210_clk_register_emc()
300 	struct device *dev = provider->dev;  in tegra210_clk_emc_attach()
304 	if (!try_module_get(provider->owner))  in tegra210_clk_emc_attach()
305 		return -ENODEV;  in tegra210_clk_emc_attach()
307 	for (i = 0; i < provider->num_configs; i++) {  in tegra210_clk_emc_attach()
308 		struct tegra210_clk_emc_config *config = &provider->configs[i];  in tegra210_clk_emc_attach()
309 		struct clk_hw *parent;  in tegra210_clk_emc_attach()  local
313 		div = FIELD_GET(CLK_SOURCE_EMC_2X_CLK_DIVISOR, config->value);  in tegra210_clk_emc_attach()
314 		src = FIELD_GET(CLK_SOURCE_EMC_2X_CLK_SRC, config->value);  in tegra210_clk_emc_attach()
318 			dev_err(dev, "invalid odd divider %u for rate %lu Hz\n",  in tegra210_clk_emc_attach()
319 				div, config->rate);  in tegra210_clk_emc_attach()
320 			err = -EINVAL;  in tegra210_clk_emc_attach()
324 		same_freq = config->value & CLK_SOURCE_EMC_MC_EMC_SAME_FREQ;  in tegra210_clk_emc_attach()
326 		if (same_freq != config->same_freq) {  in tegra210_clk_emc_attach()
328 				"ambiguous EMC to MC ratio for rate %lu Hz\n",  in tegra210_clk_emc_attach()
329 				config->rate);  in tegra210_clk_emc_attach()
330 			err = -EINVAL;  in tegra210_clk_emc_attach()
334 		parent = clk_hw_get_parent_by_index(hw, src);  in tegra210_clk_emc_attach()
335 		config->parent = src;  in tegra210_clk_emc_attach()
338 			config->parent_rate = config->rate * (1 + div / 2);  in tegra210_clk_emc_attach()
340 			unsigned long rate = config->rate * (1 + div / 2);  in tegra210_clk_emc_attach()  local
342 			config->parent_rate = clk_hw_get_rate(parent);  in tegra210_clk_emc_attach()
344 			if (config->parent_rate != rate) {  in tegra210_clk_emc_attach()
346 					"rate %lu Hz does not match input\n",  in tegra210_clk_emc_attach()
347 					config->rate);  in tegra210_clk_emc_attach()
348 				err = -EINVAL;  in tegra210_clk_emc_attach()
354 	emc->provider = provider;  in tegra210_clk_emc_attach()
359 	module_put(provider->owner);  in tegra210_clk_emc_attach()
368 	module_put(emc->provider->owner);  in tegra210_clk_emc_detach()
369 	emc->provider = NULL;  in tegra210_clk_emc_detach()