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
104struct 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
118struct ccu_div_rst_map {
119	unsigned int rst_id;
120	unsigned int clk_id;
121};
122
123struct 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 */
145static 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
182static 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 */
200static 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
257static 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
262static 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
277static 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
309static const struct reset_control_ops ccu_div_rst_ops = {
310	.reset = ccu_div_reset,
311};
312
313static 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
348err_kfree_data:
349	kfree(data);
350
351	return ERR_PTR(ret);
352}
353
354static void ccu_div_free_data(struct ccu_div_data *data)
355{
356	kfree(data->divs);
357
358	kfree(data);
359}
360
361static 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
373static 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
390static 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
439err_hw_unregister:
440	for (--idx; idx >= 0; --idx)
441		ccu_div_hw_unregister(data->divs[idx]);
442
443	return ret;
444}
445
446static 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
456static 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
472static 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
495err_clk_unregister:
496	ccu_div_clk_unregister(data);
497
498err_free_data:
499	ccu_div_free_data(data);
500}
501
502CLK_OF_DECLARE(ccu_axi, "baikal,bt1-ccu-axi", ccu_div_init);
503CLK_OF_DECLARE(ccu_sys, "baikal,bt1-ccu-sys", ccu_div_init);
504