xref: /openbmc/linux/drivers/clk/tegra/clk.c (revision 9a29f5fc)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
4  */
5 
6 #include <linux/clkdev.h>
7 #include <linux/clk.h>
8 #include <linux/clk-provider.h>
9 #include <linux/delay.h>
10 #include <linux/io.h>
11 #include <linux/of.h>
12 #include <linux/of_device.h>
13 #include <linux/clk/tegra.h>
14 #include <linux/platform_device.h>
15 #include <linux/pm_runtime.h>
16 #include <linux/reset-controller.h>
17 #include <linux/string.h>
18 
19 #include <soc/tegra/fuse.h>
20 
21 #include "clk.h"
22 
23 /* Global data of Tegra CPU CAR ops */
24 static struct device_node *tegra_car_np;
25 static struct tegra_cpu_car_ops dummy_car_ops;
26 struct tegra_cpu_car_ops *tegra_cpu_car_ops = &dummy_car_ops;
27 
28 int *periph_clk_enb_refcnt;
29 static int periph_banks;
30 static u32 *periph_state_ctx;
31 static struct clk **clks;
32 static int clk_num;
33 static struct clk_onecell_data clk_data;
34 
35 /* Handlers for SoC-specific reset lines */
36 static int (*special_reset_assert)(unsigned long);
37 static int (*special_reset_deassert)(unsigned long);
38 static unsigned int num_special_reset;
39 
40 static const struct tegra_clk_periph_regs periph_regs[] = {
41 	[0] = {
42 		.enb_reg = CLK_OUT_ENB_L,
43 		.enb_set_reg = CLK_OUT_ENB_SET_L,
44 		.enb_clr_reg = CLK_OUT_ENB_CLR_L,
45 		.rst_reg = RST_DEVICES_L,
46 		.rst_set_reg = RST_DEVICES_SET_L,
47 		.rst_clr_reg = RST_DEVICES_CLR_L,
48 	},
49 	[1] = {
50 		.enb_reg = CLK_OUT_ENB_H,
51 		.enb_set_reg = CLK_OUT_ENB_SET_H,
52 		.enb_clr_reg = CLK_OUT_ENB_CLR_H,
53 		.rst_reg = RST_DEVICES_H,
54 		.rst_set_reg = RST_DEVICES_SET_H,
55 		.rst_clr_reg = RST_DEVICES_CLR_H,
56 	},
57 	[2] = {
58 		.enb_reg = CLK_OUT_ENB_U,
59 		.enb_set_reg = CLK_OUT_ENB_SET_U,
60 		.enb_clr_reg = CLK_OUT_ENB_CLR_U,
61 		.rst_reg = RST_DEVICES_U,
62 		.rst_set_reg = RST_DEVICES_SET_U,
63 		.rst_clr_reg = RST_DEVICES_CLR_U,
64 	},
65 	[3] = {
66 		.enb_reg = CLK_OUT_ENB_V,
67 		.enb_set_reg = CLK_OUT_ENB_SET_V,
68 		.enb_clr_reg = CLK_OUT_ENB_CLR_V,
69 		.rst_reg = RST_DEVICES_V,
70 		.rst_set_reg = RST_DEVICES_SET_V,
71 		.rst_clr_reg = RST_DEVICES_CLR_V,
72 	},
73 	[4] = {
74 		.enb_reg = CLK_OUT_ENB_W,
75 		.enb_set_reg = CLK_OUT_ENB_SET_W,
76 		.enb_clr_reg = CLK_OUT_ENB_CLR_W,
77 		.rst_reg = RST_DEVICES_W,
78 		.rst_set_reg = RST_DEVICES_SET_W,
79 		.rst_clr_reg = RST_DEVICES_CLR_W,
80 	},
81 	[5] = {
82 		.enb_reg = CLK_OUT_ENB_X,
83 		.enb_set_reg = CLK_OUT_ENB_SET_X,
84 		.enb_clr_reg = CLK_OUT_ENB_CLR_X,
85 		.rst_reg = RST_DEVICES_X,
86 		.rst_set_reg = RST_DEVICES_SET_X,
87 		.rst_clr_reg = RST_DEVICES_CLR_X,
88 	},
89 	[6] = {
90 		.enb_reg = CLK_OUT_ENB_Y,
91 		.enb_set_reg = CLK_OUT_ENB_SET_Y,
92 		.enb_clr_reg = CLK_OUT_ENB_CLR_Y,
93 		.rst_reg = RST_DEVICES_Y,
94 		.rst_set_reg = RST_DEVICES_SET_Y,
95 		.rst_clr_reg = RST_DEVICES_CLR_Y,
96 	},
97 };
98 
99 static void __iomem *clk_base;
100 
101 static int tegra_clk_rst_assert(struct reset_controller_dev *rcdev,
102 		unsigned long id)
103 {
104 	/*
105 	 * If peripheral is on the APB bus then we must read the APB bus to
106 	 * flush the write operation in apb bus. This will avoid peripheral
107 	 * access after disabling clock. Since the reset driver has no
108 	 * knowledge of which reset IDs represent which devices, simply do
109 	 * this all the time.
110 	 */
111 	tegra_read_chipid();
112 
113 	if (id < periph_banks * 32) {
114 		writel_relaxed(BIT(id % 32),
115 			       clk_base + periph_regs[id / 32].rst_set_reg);
116 		return 0;
117 	} else if (id < periph_banks * 32 + num_special_reset) {
118 		return special_reset_assert(id);
119 	}
120 
121 	return -EINVAL;
122 }
123 
124 static int tegra_clk_rst_deassert(struct reset_controller_dev *rcdev,
125 		unsigned long id)
126 {
127 	if (id < periph_banks * 32) {
128 		writel_relaxed(BIT(id % 32),
129 			       clk_base + periph_regs[id / 32].rst_clr_reg);
130 		return 0;
131 	} else if (id < periph_banks * 32 + num_special_reset) {
132 		return special_reset_deassert(id);
133 	}
134 
135 	return -EINVAL;
136 }
137 
138 static int tegra_clk_rst_reset(struct reset_controller_dev *rcdev,
139 		unsigned long id)
140 {
141 	int err;
142 
143 	err = tegra_clk_rst_assert(rcdev, id);
144 	if (err)
145 		return err;
146 
147 	udelay(1);
148 
149 	return tegra_clk_rst_deassert(rcdev, id);
150 }
151 
152 const struct tegra_clk_periph_regs *get_reg_bank(int clkid)
153 {
154 	int reg_bank = clkid / 32;
155 
156 	if (reg_bank < periph_banks)
157 		return &periph_regs[reg_bank];
158 	else {
159 		WARN_ON(1);
160 		return NULL;
161 	}
162 }
163 
164 void tegra_clk_set_pllp_out_cpu(bool enable)
165 {
166 	u32 val;
167 
168 	val = readl_relaxed(clk_base + CLK_OUT_ENB_Y);
169 	if (enable)
170 		val |= CLK_ENB_PLLP_OUT_CPU;
171 	else
172 		val &= ~CLK_ENB_PLLP_OUT_CPU;
173 
174 	writel_relaxed(val, clk_base + CLK_OUT_ENB_Y);
175 }
176 
177 void tegra_clk_periph_suspend(void)
178 {
179 	unsigned int i, idx;
180 
181 	idx = 0;
182 	for (i = 0; i < periph_banks; i++, idx++)
183 		periph_state_ctx[idx] =
184 			readl_relaxed(clk_base + periph_regs[i].enb_reg);
185 
186 	for (i = 0; i < periph_banks; i++, idx++)
187 		periph_state_ctx[idx] =
188 			readl_relaxed(clk_base + periph_regs[i].rst_reg);
189 }
190 
191 void tegra_clk_periph_resume(void)
192 {
193 	unsigned int i, idx;
194 
195 	idx = 0;
196 	for (i = 0; i < periph_banks; i++, idx++)
197 		writel_relaxed(periph_state_ctx[idx],
198 			       clk_base + periph_regs[i].enb_reg);
199 	/*
200 	 * All non-boot peripherals will be in reset state on resume.
201 	 * Wait for 5us of reset propagation delay before de-asserting
202 	 * the peripherals based on the saved context.
203 	 */
204 	fence_udelay(5, clk_base);
205 
206 	for (i = 0; i < periph_banks; i++, idx++)
207 		writel_relaxed(periph_state_ctx[idx],
208 			       clk_base + periph_regs[i].rst_reg);
209 
210 	fence_udelay(2, clk_base);
211 }
212 
213 static int tegra_clk_periph_ctx_init(int banks)
214 {
215 	periph_state_ctx = kcalloc(2 * banks, sizeof(*periph_state_ctx),
216 				   GFP_KERNEL);
217 	if (!periph_state_ctx)
218 		return -ENOMEM;
219 
220 	return 0;
221 }
222 
223 struct clk ** __init tegra_clk_init(void __iomem *regs, int num, int banks)
224 {
225 	clk_base = regs;
226 
227 	if (WARN_ON(banks > ARRAY_SIZE(periph_regs)))
228 		return NULL;
229 
230 	periph_clk_enb_refcnt = kcalloc(32 * banks,
231 					sizeof(*periph_clk_enb_refcnt),
232 					GFP_KERNEL);
233 	if (!periph_clk_enb_refcnt)
234 		return NULL;
235 
236 	periph_banks = banks;
237 
238 	clks = kcalloc(num, sizeof(struct clk *), GFP_KERNEL);
239 	if (!clks) {
240 		kfree(periph_clk_enb_refcnt);
241 		return NULL;
242 	}
243 
244 	clk_num = num;
245 
246 	if (IS_ENABLED(CONFIG_PM_SLEEP)) {
247 		if (tegra_clk_periph_ctx_init(banks)) {
248 			kfree(periph_clk_enb_refcnt);
249 			kfree(clks);
250 			return NULL;
251 		}
252 	}
253 
254 	return clks;
255 }
256 
257 void __init tegra_init_dup_clks(struct tegra_clk_duplicate *dup_list,
258 				struct clk *clks[], int clk_max)
259 {
260 	struct clk *clk;
261 
262 	for (; dup_list->clk_id < clk_max; dup_list++) {
263 		clk = clks[dup_list->clk_id];
264 		dup_list->lookup.clk = clk;
265 		clkdev_add(&dup_list->lookup);
266 	}
267 }
268 
269 void tegra_init_from_table(struct tegra_clk_init_table *tbl,
270 			   struct clk *clks[], int clk_max)
271 {
272 	struct clk *clk;
273 
274 	for (; tbl->clk_id < clk_max; tbl++) {
275 		clk = clks[tbl->clk_id];
276 		if (IS_ERR_OR_NULL(clk)) {
277 			pr_err("%s: invalid entry %ld in clks array for id %d\n",
278 			       __func__, PTR_ERR(clk), tbl->clk_id);
279 			WARN_ON(1);
280 
281 			continue;
282 		}
283 
284 		if (tbl->parent_id < clk_max) {
285 			struct clk *parent = clks[tbl->parent_id];
286 			if (clk_set_parent(clk, parent)) {
287 				pr_err("%s: Failed to set parent %s of %s\n",
288 				       __func__, __clk_get_name(parent),
289 				       __clk_get_name(clk));
290 				WARN_ON(1);
291 			}
292 		}
293 
294 		if (tbl->rate)
295 			if (clk_set_rate(clk, tbl->rate)) {
296 				pr_err("%s: Failed to set rate %lu of %s\n",
297 				       __func__, tbl->rate,
298 				       __clk_get_name(clk));
299 				WARN_ON(1);
300 			}
301 
302 		if (tbl->state)
303 			if (clk_prepare_enable(clk)) {
304 				pr_err("%s: Failed to enable %s\n", __func__,
305 				       __clk_get_name(clk));
306 				WARN_ON(1);
307 			}
308 	}
309 }
310 
311 static const struct reset_control_ops rst_ops = {
312 	.assert = tegra_clk_rst_assert,
313 	.deassert = tegra_clk_rst_deassert,
314 	.reset = tegra_clk_rst_reset,
315 };
316 
317 static struct reset_controller_dev rst_ctlr = {
318 	.ops = &rst_ops,
319 	.owner = THIS_MODULE,
320 	.of_reset_n_cells = 1,
321 };
322 
323 void __init tegra_add_of_provider(struct device_node *np,
324 				  void *clk_src_onecell_get)
325 {
326 	int i;
327 
328 	tegra_car_np = np;
329 
330 	for (i = 0; i < clk_num; i++) {
331 		if (IS_ERR(clks[i])) {
332 			pr_err
333 			    ("Tegra clk %d: register failed with %ld\n",
334 			     i, PTR_ERR(clks[i]));
335 		}
336 		if (!clks[i])
337 			clks[i] = ERR_PTR(-EINVAL);
338 	}
339 
340 	clk_data.clks = clks;
341 	clk_data.clk_num = clk_num;
342 	of_clk_add_provider(np, clk_src_onecell_get, &clk_data);
343 
344 	rst_ctlr.of_node = np;
345 	rst_ctlr.nr_resets = periph_banks * 32 + num_special_reset;
346 	reset_controller_register(&rst_ctlr);
347 }
348 
349 void __init tegra_init_special_resets(unsigned int num,
350 				      int (*assert)(unsigned long),
351 				      int (*deassert)(unsigned long))
352 {
353 	num_special_reset = num;
354 	special_reset_assert = assert;
355 	special_reset_deassert = deassert;
356 }
357 
358 void tegra_register_devclks(struct tegra_devclk *dev_clks, int num)
359 {
360 	int i;
361 
362 	for (i = 0; i < num; i++, dev_clks++)
363 		clk_register_clkdev(clks[dev_clks->dt_id], dev_clks->con_id,
364 				dev_clks->dev_id);
365 
366 	for (i = 0; i < clk_num; i++) {
367 		if (!IS_ERR_OR_NULL(clks[i]))
368 			clk_register_clkdev(clks[i], __clk_get_name(clks[i]),
369 				"tegra-clk-debug");
370 	}
371 }
372 
373 struct clk ** __init tegra_lookup_dt_id(int clk_id,
374 					struct tegra_clk *tegra_clk)
375 {
376 	if (tegra_clk[clk_id].present)
377 		return &clks[tegra_clk[clk_id].dt_id];
378 	else
379 		return NULL;
380 }
381 
382 static struct device_node *tegra_clk_get_of_node(struct clk_hw *hw)
383 {
384 	struct device_node *np;
385 	char *node_name;
386 
387 	node_name = kstrdup(hw->init->name, GFP_KERNEL);
388 	if (!node_name)
389 		return NULL;
390 
391 	strreplace(node_name, '_', '-');
392 
393 	for_each_child_of_node(tegra_car_np, np) {
394 		if (!strcmp(np->name, node_name))
395 			break;
396 	}
397 
398 	kfree(node_name);
399 
400 	return np;
401 }
402 
403 struct clk *tegra_clk_dev_register(struct clk_hw *hw)
404 {
405 	struct platform_device *pdev, *parent;
406 	const char *dev_name = NULL;
407 	struct device *dev = NULL;
408 	struct device_node *np;
409 
410 	np = tegra_clk_get_of_node(hw);
411 
412 	if (!of_device_is_available(np))
413 		goto put_node;
414 
415 	dev_name = kasprintf(GFP_KERNEL, "tegra_clk_%s", hw->init->name);
416 	if (!dev_name)
417 		goto put_node;
418 
419 	parent = of_find_device_by_node(tegra_car_np);
420 	if (parent) {
421 		pdev = of_platform_device_create(np, dev_name, &parent->dev);
422 		put_device(&parent->dev);
423 
424 		if (!pdev) {
425 			pr_err("%s: failed to create device for %pOF\n",
426 			       __func__, np);
427 			goto free_name;
428 		}
429 
430 		dev = &pdev->dev;
431 		pm_runtime_enable(dev);
432 	} else {
433 		WARN(1, "failed to find device for %pOF\n", tegra_car_np);
434 	}
435 
436 free_name:
437 	kfree(dev_name);
438 put_node:
439 	of_node_put(np);
440 
441 	return clk_register(dev, hw);
442 }
443 
444 tegra_clk_apply_init_table_func tegra_clk_apply_init_table;
445 
446 static int __init tegra_clocks_apply_init_table(void)
447 {
448 	if (!tegra_clk_apply_init_table)
449 		return 0;
450 
451 	tegra_clk_apply_init_table();
452 
453 	return 0;
454 }
455 arch_initcall(tegra_clocks_apply_init_table);
456