xref: /openbmc/linux/drivers/clk/tegra/clk.c (revision 6f69e2a3)
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/clk/tegra.h>
13 #include <linux/reset-controller.h>
14 
15 #include <soc/tegra/fuse.h>
16 
17 #include "clk.h"
18 
19 /* Global data of Tegra CPU CAR ops */
20 static struct tegra_cpu_car_ops dummy_car_ops;
21 struct tegra_cpu_car_ops *tegra_cpu_car_ops = &dummy_car_ops;
22 
23 int *periph_clk_enb_refcnt;
24 static int periph_banks;
25 static u32 *periph_state_ctx;
26 static struct clk **clks;
27 static int clk_num;
28 static struct clk_onecell_data clk_data;
29 
30 /* Handlers for SoC-specific reset lines */
31 static int (*special_reset_assert)(unsigned long);
32 static int (*special_reset_deassert)(unsigned long);
33 static unsigned int num_special_reset;
34 
35 static const struct tegra_clk_periph_regs periph_regs[] = {
36 	[0] = {
37 		.enb_reg = CLK_OUT_ENB_L,
38 		.enb_set_reg = CLK_OUT_ENB_SET_L,
39 		.enb_clr_reg = CLK_OUT_ENB_CLR_L,
40 		.rst_reg = RST_DEVICES_L,
41 		.rst_set_reg = RST_DEVICES_SET_L,
42 		.rst_clr_reg = RST_DEVICES_CLR_L,
43 	},
44 	[1] = {
45 		.enb_reg = CLK_OUT_ENB_H,
46 		.enb_set_reg = CLK_OUT_ENB_SET_H,
47 		.enb_clr_reg = CLK_OUT_ENB_CLR_H,
48 		.rst_reg = RST_DEVICES_H,
49 		.rst_set_reg = RST_DEVICES_SET_H,
50 		.rst_clr_reg = RST_DEVICES_CLR_H,
51 	},
52 	[2] = {
53 		.enb_reg = CLK_OUT_ENB_U,
54 		.enb_set_reg = CLK_OUT_ENB_SET_U,
55 		.enb_clr_reg = CLK_OUT_ENB_CLR_U,
56 		.rst_reg = RST_DEVICES_U,
57 		.rst_set_reg = RST_DEVICES_SET_U,
58 		.rst_clr_reg = RST_DEVICES_CLR_U,
59 	},
60 	[3] = {
61 		.enb_reg = CLK_OUT_ENB_V,
62 		.enb_set_reg = CLK_OUT_ENB_SET_V,
63 		.enb_clr_reg = CLK_OUT_ENB_CLR_V,
64 		.rst_reg = RST_DEVICES_V,
65 		.rst_set_reg = RST_DEVICES_SET_V,
66 		.rst_clr_reg = RST_DEVICES_CLR_V,
67 	},
68 	[4] = {
69 		.enb_reg = CLK_OUT_ENB_W,
70 		.enb_set_reg = CLK_OUT_ENB_SET_W,
71 		.enb_clr_reg = CLK_OUT_ENB_CLR_W,
72 		.rst_reg = RST_DEVICES_W,
73 		.rst_set_reg = RST_DEVICES_SET_W,
74 		.rst_clr_reg = RST_DEVICES_CLR_W,
75 	},
76 	[5] = {
77 		.enb_reg = CLK_OUT_ENB_X,
78 		.enb_set_reg = CLK_OUT_ENB_SET_X,
79 		.enb_clr_reg = CLK_OUT_ENB_CLR_X,
80 		.rst_reg = RST_DEVICES_X,
81 		.rst_set_reg = RST_DEVICES_SET_X,
82 		.rst_clr_reg = RST_DEVICES_CLR_X,
83 	},
84 	[6] = {
85 		.enb_reg = CLK_OUT_ENB_Y,
86 		.enb_set_reg = CLK_OUT_ENB_SET_Y,
87 		.enb_clr_reg = CLK_OUT_ENB_CLR_Y,
88 		.rst_reg = RST_DEVICES_Y,
89 		.rst_set_reg = RST_DEVICES_SET_Y,
90 		.rst_clr_reg = RST_DEVICES_CLR_Y,
91 	},
92 };
93 
94 static void __iomem *clk_base;
95 
96 static int tegra_clk_rst_assert(struct reset_controller_dev *rcdev,
97 		unsigned long id)
98 {
99 	/*
100 	 * If peripheral is on the APB bus then we must read the APB bus to
101 	 * flush the write operation in apb bus. This will avoid peripheral
102 	 * access after disabling clock. Since the reset driver has no
103 	 * knowledge of which reset IDs represent which devices, simply do
104 	 * this all the time.
105 	 */
106 	tegra_read_chipid();
107 
108 	if (id < periph_banks * 32) {
109 		writel_relaxed(BIT(id % 32),
110 			       clk_base + periph_regs[id / 32].rst_set_reg);
111 		return 0;
112 	} else if (id < periph_banks * 32 + num_special_reset) {
113 		return special_reset_assert(id);
114 	}
115 
116 	return -EINVAL;
117 }
118 
119 static int tegra_clk_rst_deassert(struct reset_controller_dev *rcdev,
120 		unsigned long id)
121 {
122 	if (id < periph_banks * 32) {
123 		writel_relaxed(BIT(id % 32),
124 			       clk_base + periph_regs[id / 32].rst_clr_reg);
125 		return 0;
126 	} else if (id < periph_banks * 32 + num_special_reset) {
127 		return special_reset_deassert(id);
128 	}
129 
130 	return -EINVAL;
131 }
132 
133 static int tegra_clk_rst_reset(struct reset_controller_dev *rcdev,
134 		unsigned long id)
135 {
136 	int err;
137 
138 	err = tegra_clk_rst_assert(rcdev, id);
139 	if (err)
140 		return err;
141 
142 	udelay(1);
143 
144 	return tegra_clk_rst_deassert(rcdev, id);
145 }
146 
147 const struct tegra_clk_periph_regs *get_reg_bank(int clkid)
148 {
149 	int reg_bank = clkid / 32;
150 
151 	if (reg_bank < periph_banks)
152 		return &periph_regs[reg_bank];
153 	else {
154 		WARN_ON(1);
155 		return NULL;
156 	}
157 }
158 
159 void tegra_clk_set_pllp_out_cpu(bool enable)
160 {
161 	u32 val;
162 
163 	val = readl_relaxed(clk_base + CLK_OUT_ENB_Y);
164 	if (enable)
165 		val |= CLK_ENB_PLLP_OUT_CPU;
166 	else
167 		val &= ~CLK_ENB_PLLP_OUT_CPU;
168 
169 	writel_relaxed(val, clk_base + CLK_OUT_ENB_Y);
170 }
171 
172 void tegra_clk_periph_suspend(void)
173 {
174 	unsigned int i, idx;
175 
176 	idx = 0;
177 	for (i = 0; i < periph_banks; i++, idx++)
178 		periph_state_ctx[idx] =
179 			readl_relaxed(clk_base + periph_regs[i].enb_reg);
180 
181 	for (i = 0; i < periph_banks; i++, idx++)
182 		periph_state_ctx[idx] =
183 			readl_relaxed(clk_base + periph_regs[i].rst_reg);
184 }
185 
186 void tegra_clk_periph_resume(void)
187 {
188 	unsigned int i, idx;
189 
190 	idx = 0;
191 	for (i = 0; i < periph_banks; i++, idx++)
192 		writel_relaxed(periph_state_ctx[idx],
193 			       clk_base + periph_regs[i].enb_reg);
194 	/*
195 	 * All non-boot peripherals will be in reset state on resume.
196 	 * Wait for 5us of reset propagation delay before de-asserting
197 	 * the peripherals based on the saved context.
198 	 */
199 	fence_udelay(5, clk_base);
200 
201 	for (i = 0; i < periph_banks; i++, idx++)
202 		writel_relaxed(periph_state_ctx[idx],
203 			       clk_base + periph_regs[i].rst_reg);
204 
205 	fence_udelay(2, clk_base);
206 }
207 
208 static int tegra_clk_periph_ctx_init(int banks)
209 {
210 	periph_state_ctx = kcalloc(2 * banks, sizeof(*periph_state_ctx),
211 				   GFP_KERNEL);
212 	if (!periph_state_ctx)
213 		return -ENOMEM;
214 
215 	return 0;
216 }
217 
218 struct clk ** __init tegra_clk_init(void __iomem *regs, int num, int banks)
219 {
220 	clk_base = regs;
221 
222 	if (WARN_ON(banks > ARRAY_SIZE(periph_regs)))
223 		return NULL;
224 
225 	periph_clk_enb_refcnt = kcalloc(32 * banks,
226 					sizeof(*periph_clk_enb_refcnt),
227 					GFP_KERNEL);
228 	if (!periph_clk_enb_refcnt)
229 		return NULL;
230 
231 	periph_banks = banks;
232 
233 	clks = kcalloc(num, sizeof(struct clk *), GFP_KERNEL);
234 	if (!clks)
235 		kfree(periph_clk_enb_refcnt);
236 
237 	clk_num = num;
238 
239 	if (IS_ENABLED(CONFIG_PM_SLEEP)) {
240 		if (tegra_clk_periph_ctx_init(banks)) {
241 			kfree(periph_clk_enb_refcnt);
242 			kfree(clks);
243 			return NULL;
244 		}
245 	}
246 
247 	return clks;
248 }
249 
250 void __init tegra_init_dup_clks(struct tegra_clk_duplicate *dup_list,
251 				struct clk *clks[], int clk_max)
252 {
253 	struct clk *clk;
254 
255 	for (; dup_list->clk_id < clk_max; dup_list++) {
256 		clk = clks[dup_list->clk_id];
257 		dup_list->lookup.clk = clk;
258 		clkdev_add(&dup_list->lookup);
259 	}
260 }
261 
262 void __init tegra_init_from_table(struct tegra_clk_init_table *tbl,
263 				  struct clk *clks[], int clk_max)
264 {
265 	struct clk *clk;
266 
267 	for (; tbl->clk_id < clk_max; tbl++) {
268 		clk = clks[tbl->clk_id];
269 		if (IS_ERR_OR_NULL(clk)) {
270 			pr_err("%s: invalid entry %ld in clks array for id %d\n",
271 			       __func__, PTR_ERR(clk), tbl->clk_id);
272 			WARN_ON(1);
273 
274 			continue;
275 		}
276 
277 		if (tbl->parent_id < clk_max) {
278 			struct clk *parent = clks[tbl->parent_id];
279 			if (clk_set_parent(clk, parent)) {
280 				pr_err("%s: Failed to set parent %s of %s\n",
281 				       __func__, __clk_get_name(parent),
282 				       __clk_get_name(clk));
283 				WARN_ON(1);
284 			}
285 		}
286 
287 		if (tbl->rate)
288 			if (clk_set_rate(clk, tbl->rate)) {
289 				pr_err("%s: Failed to set rate %lu of %s\n",
290 				       __func__, tbl->rate,
291 				       __clk_get_name(clk));
292 				WARN_ON(1);
293 			}
294 
295 		if (tbl->state)
296 			if (clk_prepare_enable(clk)) {
297 				pr_err("%s: Failed to enable %s\n", __func__,
298 				       __clk_get_name(clk));
299 				WARN_ON(1);
300 			}
301 	}
302 }
303 
304 static const struct reset_control_ops rst_ops = {
305 	.assert = tegra_clk_rst_assert,
306 	.deassert = tegra_clk_rst_deassert,
307 	.reset = tegra_clk_rst_reset,
308 };
309 
310 static struct reset_controller_dev rst_ctlr = {
311 	.ops = &rst_ops,
312 	.owner = THIS_MODULE,
313 	.of_reset_n_cells = 1,
314 };
315 
316 void __init tegra_add_of_provider(struct device_node *np,
317 				  void *clk_src_onecell_get)
318 {
319 	int i;
320 
321 	for (i = 0; i < clk_num; i++) {
322 		if (IS_ERR(clks[i])) {
323 			pr_err
324 			    ("Tegra clk %d: register failed with %ld\n",
325 			     i, PTR_ERR(clks[i]));
326 		}
327 		if (!clks[i])
328 			clks[i] = ERR_PTR(-EINVAL);
329 	}
330 
331 	clk_data.clks = clks;
332 	clk_data.clk_num = clk_num;
333 	of_clk_add_provider(np, clk_src_onecell_get, &clk_data);
334 
335 	rst_ctlr.of_node = np;
336 	rst_ctlr.nr_resets = periph_banks * 32 + num_special_reset;
337 	reset_controller_register(&rst_ctlr);
338 }
339 
340 void __init tegra_init_special_resets(unsigned int num,
341 				      int (*assert)(unsigned long),
342 				      int (*deassert)(unsigned long))
343 {
344 	num_special_reset = num;
345 	special_reset_assert = assert;
346 	special_reset_deassert = deassert;
347 }
348 
349 void __init tegra_register_devclks(struct tegra_devclk *dev_clks, int num)
350 {
351 	int i;
352 
353 	for (i = 0; i < num; i++, dev_clks++)
354 		clk_register_clkdev(clks[dev_clks->dt_id], dev_clks->con_id,
355 				dev_clks->dev_id);
356 
357 	for (i = 0; i < clk_num; i++) {
358 		if (!IS_ERR_OR_NULL(clks[i]))
359 			clk_register_clkdev(clks[i], __clk_get_name(clks[i]),
360 				"tegra-clk-debug");
361 	}
362 }
363 
364 struct clk ** __init tegra_lookup_dt_id(int clk_id,
365 					struct tegra_clk *tegra_clk)
366 {
367 	if (tegra_clk[clk_id].present)
368 		return &clks[tegra_clk[clk_id].dt_id];
369 	else
370 		return NULL;
371 }
372 
373 tegra_clk_apply_init_table_func tegra_clk_apply_init_table;
374 
375 static int __init tegra_clocks_apply_init_table(void)
376 {
377 	if (!tegra_clk_apply_init_table)
378 		return 0;
379 
380 	tegra_clk_apply_init_table();
381 
382 	return 0;
383 }
384 arch_initcall(tegra_clocks_apply_init_table);
385