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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2020 BAIKAL ELECTRONICS, JSC
4  *
5  * Authors:
6  *   Serge Semin <Sergey.Semin@baikalelectronics.ru>
7  *   Dmitry Dunaev <dmitry.dunaev@baikalelectronics.ru>
8  *
9  * Baikal-T1 CCU Dividers clock driver
10  */
11 
12 #define pr_fmt(fmt) "bt1-ccu-div: " fmt
13 
14 #include <linux/kernel.h>
15 #include <linux/printk.h>
16 #include <linux/slab.h>
17 #include <linux/clk-provider.h>
18 #include <linux/reset-controller.h>
19 #include <linux/mfd/syscon.h>
20 #include <linux/of.h>
21 #include <linux/of_address.h>
22 #include <linux/of_platform.h>
23 #include <linux/ioport.h>
24 #include <linux/regmap.h>
25 
26 #include <dt-bindings/clock/bt1-ccu.h>
27 #include <dt-bindings/reset/bt1-ccu.h>
28 
29 #include "ccu-div.h"
30 
31 #define CCU_AXI_MAIN_BASE		0x030
32 #define CCU_AXI_DDR_BASE		0x034
33 #define CCU_AXI_SATA_BASE		0x038
34 #define CCU_AXI_GMAC0_BASE		0x03C
35 #define CCU_AXI_GMAC1_BASE		0x040
36 #define CCU_AXI_XGMAC_BASE		0x044
37 #define CCU_AXI_PCIE_M_BASE		0x048
38 #define CCU_AXI_PCIE_S_BASE		0x04C
39 #define CCU_AXI_USB_BASE		0x050
40 #define CCU_AXI_HWA_BASE		0x054
41 #define CCU_AXI_SRAM_BASE		0x058
42 
43 #define CCU_SYS_SATA_REF_BASE		0x060
44 #define CCU_SYS_APB_BASE		0x064
45 #define CCU_SYS_GMAC0_BASE		0x068
46 #define CCU_SYS_GMAC1_BASE		0x06C
47 #define CCU_SYS_XGMAC_BASE		0x070
48 #define CCU_SYS_USB_BASE		0x074
49 #define CCU_SYS_PVT_BASE		0x078
50 #define CCU_SYS_HWA_BASE		0x07C
51 #define CCU_SYS_UART_BASE		0x084
52 #define CCU_SYS_TIMER0_BASE		0x088
53 #define CCU_SYS_TIMER1_BASE		0x08C
54 #define CCU_SYS_TIMER2_BASE		0x090
55 #define CCU_SYS_WDT_BASE		0x150
56 
57 #define CCU_DIV_VAR_INFO(_id, _name, _pname, _base, _width, _flags, _features) \
58 	{								\
59 		.id = _id,						\
60 		.name = _name,						\
61 		.parent_name = _pname,					\
62 		.base = _base,						\
63 		.type = CCU_DIV_VAR,					\
64 		.width = _width,					\
65 		.flags = _flags,					\
66 		.features = _features					\
67 	}
68 
69 #define CCU_DIV_GATE_INFO(_id, _name, _pname, _base, _divider)	\
70 	{							\
71 		.id = _id,					\
72 		.name = _name,					\
73 		.parent_name = _pname,				\
74 		.base = _base,					\
75 		.type = CCU_DIV_GATE,				\
76 		.divider = _divider				\
77 	}
78 
79 #define CCU_DIV_BUF_INFO(_id, _name, _pname, _base, _flags)	\
80 	{							\
81 		.id = _id,					\
82 		.name = _name,					\
83 		.parent_name = _pname,				\
84 		.base = _base,					\
85 		.type = CCU_DIV_BUF,				\
86 		.flags = _flags					\
87 	}
88 
89 #define CCU_DIV_FIXED_INFO(_id, _name, _pname, _divider)	\
90 	{							\
91 		.id = _id,					\
92 		.name = _name,					\
93 		.parent_name = _pname,				\
94 		.type = CCU_DIV_FIXED,				\
95 		.divider = _divider				\
96 	}
97 
98 #define CCU_DIV_RST_MAP(_rst_id, _clk_id)	\
99 	{					\
100 		.rst_id = _rst_id,		\
101 		.clk_id = _clk_id		\
102 	}
103 
104 struct ccu_div_info {
105 	unsigned int id;
106 	const char *name;
107 	const char *parent_name;
108 	unsigned int base;
109 	enum ccu_div_type type;
110 	union {
111 		unsigned int width;
112 		unsigned int divider;
113 	};
114 	unsigned long flags;
115 	unsigned long features;
116 };
117 
118 struct ccu_div_rst_map {
119 	unsigned int rst_id;
120 	unsigned int clk_id;
121 };
122 
123 struct ccu_div_data {
124 	struct device_node *np;
125 	struct regmap *sys_regs;
126 
127 	unsigned int divs_num;
128 	const struct ccu_div_info *divs_info;
129 	struct ccu_div **divs;
130 
131 	unsigned int rst_num;
132 	const struct ccu_div_rst_map *rst_map;
133 	struct reset_controller_dev rcdev;
134 };
135 #define to_ccu_div_data(_rcdev) container_of(_rcdev, struct ccu_div_data, rcdev)
136 
137 /*
138  * AXI Main Interconnect (axi_main_clk) and DDR AXI-bus (axi_ddr_clk) clocks
139  * must be left enabled in any case, since former one is responsible for
140  * clocking a bus between CPU cores and the rest of the SoC components, while
141  * the later is clocking the AXI-bus between DDR controller and the Main
142  * Interconnect. So should any of these clocks get to be disabled, the system
143  * will literally stop working. That's why we marked them as critical.
144  */
145 static const struct ccu_div_info axi_info[] = {
146 	CCU_DIV_VAR_INFO(CCU_AXI_MAIN_CLK, "axi_main_clk", "pcie_clk",
147 			 CCU_AXI_MAIN_BASE, 4,
148 			 CLK_IS_CRITICAL, CCU_DIV_RESET_DOMAIN),
149 	CCU_DIV_VAR_INFO(CCU_AXI_DDR_CLK, "axi_ddr_clk", "sata_clk",
150 			 CCU_AXI_DDR_BASE, 4,
151 			 CLK_IS_CRITICAL | CLK_SET_RATE_GATE,
152 			 CCU_DIV_RESET_DOMAIN),
153 	CCU_DIV_VAR_INFO(CCU_AXI_SATA_CLK, "axi_sata_clk", "sata_clk",
154 			 CCU_AXI_SATA_BASE, 4,
155 			 CLK_SET_RATE_GATE, CCU_DIV_RESET_DOMAIN),
156 	CCU_DIV_VAR_INFO(CCU_AXI_GMAC0_CLK, "axi_gmac0_clk", "eth_clk",
157 			 CCU_AXI_GMAC0_BASE, 4,
158 			 CLK_SET_RATE_GATE, CCU_DIV_RESET_DOMAIN),
159 	CCU_DIV_VAR_INFO(CCU_AXI_GMAC1_CLK, "axi_gmac1_clk", "eth_clk",
160 			 CCU_AXI_GMAC1_BASE, 4,
161 			 CLK_SET_RATE_GATE, CCU_DIV_RESET_DOMAIN),
162 	CCU_DIV_VAR_INFO(CCU_AXI_XGMAC_CLK, "axi_xgmac_clk", "eth_clk",
163 			 CCU_AXI_XGMAC_BASE, 4,
164 			 CLK_SET_RATE_GATE, CCU_DIV_RESET_DOMAIN),
165 	CCU_DIV_VAR_INFO(CCU_AXI_PCIE_M_CLK, "axi_pcie_m_clk", "pcie_clk",
166 			 CCU_AXI_PCIE_M_BASE, 4,
167 			 CLK_SET_RATE_GATE, CCU_DIV_RESET_DOMAIN),
168 	CCU_DIV_VAR_INFO(CCU_AXI_PCIE_S_CLK, "axi_pcie_s_clk", "pcie_clk",
169 			 CCU_AXI_PCIE_S_BASE, 4,
170 			 CLK_SET_RATE_GATE, CCU_DIV_RESET_DOMAIN),
171 	CCU_DIV_VAR_INFO(CCU_AXI_USB_CLK, "axi_usb_clk", "sata_clk",
172 			 CCU_AXI_USB_BASE, 4,
173 			 CLK_SET_RATE_GATE, CCU_DIV_RESET_DOMAIN),
174 	CCU_DIV_VAR_INFO(CCU_AXI_HWA_CLK, "axi_hwa_clk", "sata_clk",
175 			 CCU_AXI_HWA_BASE, 4,
176 			 CLK_SET_RATE_GATE, CCU_DIV_RESET_DOMAIN),
177 	CCU_DIV_VAR_INFO(CCU_AXI_SRAM_CLK, "axi_sram_clk", "eth_clk",
178 			 CCU_AXI_SRAM_BASE, 4,
179 			 CLK_SET_RATE_GATE, CCU_DIV_RESET_DOMAIN)
180 };
181 
182 static const struct ccu_div_rst_map axi_rst_map[] = {
183 	CCU_DIV_RST_MAP(CCU_AXI_MAIN_RST, CCU_AXI_MAIN_CLK),
184 	CCU_DIV_RST_MAP(CCU_AXI_DDR_RST, CCU_AXI_DDR_CLK),
185 	CCU_DIV_RST_MAP(CCU_AXI_SATA_RST, CCU_AXI_SATA_CLK),
186 	CCU_DIV_RST_MAP(CCU_AXI_GMAC0_RST, CCU_AXI_GMAC0_CLK),
187 	CCU_DIV_RST_MAP(CCU_AXI_GMAC1_RST, CCU_AXI_GMAC1_CLK),
188 	CCU_DIV_RST_MAP(CCU_AXI_XGMAC_RST, CCU_AXI_XGMAC_CLK),
189 	CCU_DIV_RST_MAP(CCU_AXI_PCIE_M_RST, CCU_AXI_PCIE_M_CLK),
190 	CCU_DIV_RST_MAP(CCU_AXI_PCIE_S_RST, CCU_AXI_PCIE_S_CLK),
191 	CCU_DIV_RST_MAP(CCU_AXI_USB_RST, CCU_AXI_USB_CLK),
192 	CCU_DIV_RST_MAP(CCU_AXI_HWA_RST, CCU_AXI_HWA_CLK),
193 	CCU_DIV_RST_MAP(CCU_AXI_SRAM_RST, CCU_AXI_SRAM_CLK)
194 };
195 
196 /*
197  * APB-bus clock is marked as critical since it's a main communication bus
198  * for the SoC devices registers IO-operations.
199  */
200 static const struct ccu_div_info sys_info[] = {
201 	CCU_DIV_VAR_INFO(CCU_SYS_SATA_CLK, "sys_sata_clk",
202 			 "sata_clk", CCU_SYS_SATA_REF_BASE, 4,
203 			 CLK_SET_RATE_GATE,
204 			 CCU_DIV_SKIP_ONE | CCU_DIV_LOCK_SHIFTED |
205 			 CCU_DIV_RESET_DOMAIN),
206 	CCU_DIV_BUF_INFO(CCU_SYS_SATA_REF_CLK, "sys_sata_ref_clk",
207 			 "sys_sata_clk", CCU_SYS_SATA_REF_BASE,
208 			 CLK_SET_RATE_PARENT),
209 	CCU_DIV_VAR_INFO(CCU_SYS_APB_CLK, "sys_apb_clk",
210 			 "pcie_clk", CCU_SYS_APB_BASE, 5,
211 			 CLK_IS_CRITICAL, CCU_DIV_RESET_DOMAIN),
212 	CCU_DIV_GATE_INFO(CCU_SYS_GMAC0_TX_CLK, "sys_gmac0_tx_clk",
213 			  "eth_clk", CCU_SYS_GMAC0_BASE, 5),
214 	CCU_DIV_FIXED_INFO(CCU_SYS_GMAC0_PTP_CLK, "sys_gmac0_ptp_clk",
215 			   "eth_clk", 10),
216 	CCU_DIV_GATE_INFO(CCU_SYS_GMAC1_TX_CLK, "sys_gmac1_tx_clk",
217 			  "eth_clk", CCU_SYS_GMAC1_BASE, 5),
218 	CCU_DIV_FIXED_INFO(CCU_SYS_GMAC1_PTP_CLK, "sys_gmac1_ptp_clk",
219 			   "eth_clk", 10),
220 	CCU_DIV_GATE_INFO(CCU_SYS_XGMAC_CLK, "sys_xgmac_clk",
221 			  "eth_clk", CCU_SYS_XGMAC_BASE, 1),
222 	CCU_DIV_FIXED_INFO(CCU_SYS_XGMAC_REF_CLK, "sys_xgmac_ref_clk",
223 			   "sys_xgmac_clk", 8),
224 	CCU_DIV_FIXED_INFO(CCU_SYS_XGMAC_PTP_CLK, "sys_xgmac_ptp_clk",
225 			   "sys_xgmac_clk", 8),
226 	CCU_DIV_GATE_INFO(CCU_SYS_USB_CLK, "sys_usb_clk",
227 			  "eth_clk", CCU_SYS_USB_BASE, 10),
228 	CCU_DIV_VAR_INFO(CCU_SYS_PVT_CLK, "sys_pvt_clk",
229 			 "ref_clk", CCU_SYS_PVT_BASE, 5,
230 			 CLK_SET_RATE_GATE, 0),
231 	CCU_DIV_VAR_INFO(CCU_SYS_HWA_CLK, "sys_hwa_clk",
232 			 "sata_clk", CCU_SYS_HWA_BASE, 4,
233 			 CLK_SET_RATE_GATE, 0),
234 	CCU_DIV_VAR_INFO(CCU_SYS_UART_CLK, "sys_uart_clk",
235 			 "eth_clk", CCU_SYS_UART_BASE, 17,
236 			 CLK_SET_RATE_GATE, 0),
237 	CCU_DIV_FIXED_INFO(CCU_SYS_I2C1_CLK, "sys_i2c1_clk",
238 			   "eth_clk", 10),
239 	CCU_DIV_FIXED_INFO(CCU_SYS_I2C2_CLK, "sys_i2c2_clk",
240 			   "eth_clk", 10),
241 	CCU_DIV_FIXED_INFO(CCU_SYS_GPIO_CLK, "sys_gpio_clk",
242 			   "ref_clk", 25),
243 	CCU_DIV_VAR_INFO(CCU_SYS_TIMER0_CLK, "sys_timer0_clk",
244 			 "ref_clk", CCU_SYS_TIMER0_BASE, 17,
245 			 CLK_SET_RATE_GATE, 0),
246 	CCU_DIV_VAR_INFO(CCU_SYS_TIMER1_CLK, "sys_timer1_clk",
247 			 "ref_clk", CCU_SYS_TIMER1_BASE, 17,
248 			 CLK_SET_RATE_GATE, 0),
249 	CCU_DIV_VAR_INFO(CCU_SYS_TIMER2_CLK, "sys_timer2_clk",
250 			 "ref_clk", CCU_SYS_TIMER2_BASE, 17,
251 			 CLK_SET_RATE_GATE, 0),
252 	CCU_DIV_VAR_INFO(CCU_SYS_WDT_CLK, "sys_wdt_clk",
253 			 "eth_clk", CCU_SYS_WDT_BASE, 17,
254 			 CLK_SET_RATE_GATE, CCU_DIV_SKIP_ONE_TO_THREE)
255 };
256 
257 static const struct ccu_div_rst_map sys_rst_map[] = {
258 	CCU_DIV_RST_MAP(CCU_SYS_SATA_REF_RST, CCU_SYS_SATA_REF_CLK),
259 	CCU_DIV_RST_MAP(CCU_SYS_APB_RST, CCU_SYS_APB_CLK),
260 };
261 
ccu_div_find_desc(struct ccu_div_data * data,unsigned int clk_id)262 static struct ccu_div *ccu_div_find_desc(struct ccu_div_data *data,
263 					 unsigned int clk_id)
264 {
265 	struct ccu_div *div;
266 	int idx;
267 
268 	for (idx = 0; idx < data->divs_num; ++idx) {
269 		div = data->divs[idx];
270 		if (div && div->id == clk_id)
271 			return div;
272 	}
273 
274 	return ERR_PTR(-EINVAL);
275 }
276 
ccu_div_reset(struct reset_controller_dev * rcdev,unsigned long rst_id)277 static int ccu_div_reset(struct reset_controller_dev *rcdev,
278 			 unsigned long rst_id)
279 {
280 	struct ccu_div_data *data = to_ccu_div_data(rcdev);
281 	const struct ccu_div_rst_map *map;
282 	struct ccu_div *div;
283 	int idx, ret;
284 
285 	for (idx = 0, map = data->rst_map; idx < data->rst_num; ++idx, ++map) {
286 		if (map->rst_id == rst_id)
287 			break;
288 	}
289 	if (idx == data->rst_num) {
290 		pr_err("Invalid reset ID %lu specified\n", rst_id);
291 		return -EINVAL;
292 	}
293 
294 	div = ccu_div_find_desc(data, map->clk_id);
295 	if (IS_ERR(div)) {
296 		pr_err("Invalid clock ID %d in mapping\n", map->clk_id);
297 		return PTR_ERR(div);
298 	}
299 
300 	ret = ccu_div_reset_domain(div);
301 	if (ret) {
302 		pr_err("Reset isn't supported by divider %s\n",
303 			clk_hw_get_name(ccu_div_get_clk_hw(div)));
304 	}
305 
306 	return ret;
307 }
308 
309 static const struct reset_control_ops ccu_div_rst_ops = {
310 	.reset = ccu_div_reset,
311 };
312 
ccu_div_create_data(struct device_node * np)313 static struct ccu_div_data *ccu_div_create_data(struct device_node *np)
314 {
315 	struct ccu_div_data *data;
316 	int ret;
317 
318 	data = kzalloc(sizeof(*data), GFP_KERNEL);
319 	if (!data)
320 		return ERR_PTR(-ENOMEM);
321 
322 	data->np = np;
323 	if (of_device_is_compatible(np, "baikal,bt1-ccu-axi")) {
324 		data->divs_num = ARRAY_SIZE(axi_info);
325 		data->divs_info = axi_info;
326 		data->rst_num = ARRAY_SIZE(axi_rst_map);
327 		data->rst_map = axi_rst_map;
328 	} else if (of_device_is_compatible(np, "baikal,bt1-ccu-sys")) {
329 		data->divs_num = ARRAY_SIZE(sys_info);
330 		data->divs_info = sys_info;
331 		data->rst_num = ARRAY_SIZE(sys_rst_map);
332 		data->rst_map = sys_rst_map;
333 	} else {
334 		pr_err("Incompatible DT node '%s' specified\n",
335 			of_node_full_name(np));
336 		ret = -EINVAL;
337 		goto err_kfree_data;
338 	}
339 
340 	data->divs = kcalloc(data->divs_num, sizeof(*data->divs), GFP_KERNEL);
341 	if (!data->divs) {
342 		ret = -ENOMEM;
343 		goto err_kfree_data;
344 	}
345 
346 	return data;
347 
348 err_kfree_data:
349 	kfree(data);
350 
351 	return ERR_PTR(ret);
352 }
353 
ccu_div_free_data(struct ccu_div_data * data)354 static void ccu_div_free_data(struct ccu_div_data *data)
355 {
356 	kfree(data->divs);
357 
358 	kfree(data);
359 }
360 
ccu_div_find_sys_regs(struct ccu_div_data * data)361 static int ccu_div_find_sys_regs(struct ccu_div_data *data)
362 {
363 	data->sys_regs = syscon_node_to_regmap(data->np->parent);
364 	if (IS_ERR(data->sys_regs)) {
365 		pr_err("Failed to find syscon regs for '%s'\n",
366 			of_node_full_name(data->np));
367 		return PTR_ERR(data->sys_regs);
368 	}
369 
370 	return 0;
371 }
372 
ccu_div_of_clk_hw_get(struct of_phandle_args * clkspec,void * priv)373 static struct clk_hw *ccu_div_of_clk_hw_get(struct of_phandle_args *clkspec,
374 					    void *priv)
375 {
376 	struct ccu_div_data *data = priv;
377 	struct ccu_div *div;
378 	unsigned int clk_id;
379 
380 	clk_id = clkspec->args[0];
381 	div = ccu_div_find_desc(data, clk_id);
382 	if (IS_ERR(div)) {
383 		pr_info("Invalid clock ID %d specified\n", clk_id);
384 		return ERR_CAST(div);
385 	}
386 
387 	return ccu_div_get_clk_hw(div);
388 }
389 
ccu_div_clk_register(struct ccu_div_data * data)390 static int ccu_div_clk_register(struct ccu_div_data *data)
391 {
392 	int idx, ret;
393 
394 	for (idx = 0; idx < data->divs_num; ++idx) {
395 		const struct ccu_div_info *info = &data->divs_info[idx];
396 		struct ccu_div_init_data init = {0};
397 
398 		init.id = info->id;
399 		init.name = info->name;
400 		init.parent_name = info->parent_name;
401 		init.np = data->np;
402 		init.type = info->type;
403 		init.flags = info->flags;
404 		init.features = info->features;
405 
406 		if (init.type == CCU_DIV_VAR) {
407 			init.base = info->base;
408 			init.sys_regs = data->sys_regs;
409 			init.width = info->width;
410 		} else if (init.type == CCU_DIV_GATE) {
411 			init.base = info->base;
412 			init.sys_regs = data->sys_regs;
413 			init.divider = info->divider;
414 		} else if (init.type == CCU_DIV_BUF) {
415 			init.base = info->base;
416 			init.sys_regs = data->sys_regs;
417 		} else {
418 			init.divider = info->divider;
419 		}
420 
421 		data->divs[idx] = ccu_div_hw_register(&init);
422 		if (IS_ERR(data->divs[idx])) {
423 			ret = PTR_ERR(data->divs[idx]);
424 			pr_err("Couldn't register divider '%s' hw\n",
425 				init.name);
426 			goto err_hw_unregister;
427 		}
428 	}
429 
430 	ret = of_clk_add_hw_provider(data->np, ccu_div_of_clk_hw_get, data);
431 	if (ret) {
432 		pr_err("Couldn't register dividers '%s' clock provider\n",
433 			of_node_full_name(data->np));
434 		goto err_hw_unregister;
435 	}
436 
437 	return 0;
438 
439 err_hw_unregister:
440 	for (--idx; idx >= 0; --idx)
441 		ccu_div_hw_unregister(data->divs[idx]);
442 
443 	return ret;
444 }
445 
ccu_div_clk_unregister(struct ccu_div_data * data)446 static void ccu_div_clk_unregister(struct ccu_div_data *data)
447 {
448 	int idx;
449 
450 	of_clk_del_provider(data->np);
451 
452 	for (idx = 0; idx < data->divs_num; ++idx)
453 		ccu_div_hw_unregister(data->divs[idx]);
454 }
455 
ccu_div_rst_register(struct ccu_div_data * data)456 static int ccu_div_rst_register(struct ccu_div_data *data)
457 {
458 	int ret;
459 
460 	data->rcdev.ops = &ccu_div_rst_ops;
461 	data->rcdev.of_node = data->np;
462 	data->rcdev.nr_resets = data->rst_num;
463 
464 	ret = reset_controller_register(&data->rcdev);
465 	if (ret)
466 		pr_err("Couldn't register divider '%s' reset controller\n",
467 			of_node_full_name(data->np));
468 
469 	return ret;
470 }
471 
ccu_div_init(struct device_node * np)472 static void ccu_div_init(struct device_node *np)
473 {
474 	struct ccu_div_data *data;
475 	int ret;
476 
477 	data = ccu_div_create_data(np);
478 	if (IS_ERR(data))
479 		return;
480 
481 	ret = ccu_div_find_sys_regs(data);
482 	if (ret)
483 		goto err_free_data;
484 
485 	ret = ccu_div_clk_register(data);
486 	if (ret)
487 		goto err_free_data;
488 
489 	ret = ccu_div_rst_register(data);
490 	if (ret)
491 		goto err_clk_unregister;
492 
493 	return;
494 
495 err_clk_unregister:
496 	ccu_div_clk_unregister(data);
497 
498 err_free_data:
499 	ccu_div_free_data(data);
500 }
501 
502 CLK_OF_DECLARE(ccu_axi, "baikal,bt1-ccu-axi", ccu_div_init);
503 CLK_OF_DECLARE(ccu_sys, "baikal,bt1-ccu-sys", ccu_div_init);
504