xref: /linux/drivers/reset/reset-k230.c (revision 260f6f4fda93c8485c8037865c941b42b9cba5d2)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2022-2024 Canaan Bright Sight Co., Ltd
4  * Copyright (C) 2024-2025 Junhui Liu <junhui.liu@pigmoral.tech>
5  *
6  * The reset management module in the K230 SoC provides reset time control
7  * registers. For RST_TYPE_CPU0, RST_TYPE_CPU1 and RST_TYPE_SW_DONE, the period
8  * during which reset is applied or removed while the clock is stopped can be
9  * set up to 15 * 0.25 = 3.75 µs. For RST_TYPE_HW_DONE, that period can be set
10  * up to 255 * 0.25 = 63.75 µs. For RST_TYPE_FLUSH, the reset bit is
11  * automatically cleared by hardware when flush completes.
12  *
13  * Although this driver does not configure the reset time registers, delays have
14  * been added to the assert, deassert, and reset operations to cover the maximum
15  * reset time. Some reset types include done bits whose toggle does not
16  * unambiguously signal whether hardware reset removal or clock-stop period
17  * expiration occurred first. Delays are therefore retained for types with done
18  * bits to ensure safe timing.
19  *
20  * Reference: K230 Technical Reference Manual V0.3.1
21  * https://kendryte-download.canaan-creative.com/developer/k230/HDK/K230%E7%A1%AC%E4%BB%B6%E6%96%87%E6%A1%A3/K230_Technical_Reference_Manual_V0.3.1_20241118.pdf
22  */
23 
24 #include <linux/cleanup.h>
25 #include <linux/delay.h>
26 #include <linux/io.h>
27 #include <linux/iopoll.h>
28 #include <linux/of.h>
29 #include <linux/platform_device.h>
30 #include <linux/reset-controller.h>
31 #include <linux/spinlock.h>
32 
33 #include <dt-bindings/reset/canaan,k230-rst.h>
34 
35 /**
36  * enum k230_rst_type - K230 reset types
37  * @RST_TYPE_CPU0: Reset type for CPU0
38  *	Automatically clears, has write enable and done bit, active high
39  * @RST_TYPE_CPU1: Reset type for CPU1
40  *	Manually clears, has write enable and done bit, active high
41  * @RST_TYPE_FLUSH: Reset type for CPU L2 cache flush
42  *	Automatically clears, has write enable, no done bit, active high
43  * @RST_TYPE_HW_DONE: Reset type for hardware auto clear
44  *	Automatically clears, no write enable, has done bit, active high
45  * @RST_TYPE_SW_DONE: Reset type for software manual clear
46  *	Manually clears, no write enable and done bit,
47  *	active high if ID is RST_SPI2AXI, otherwise active low
48  */
49 enum k230_rst_type {
50 	RST_TYPE_CPU0,
51 	RST_TYPE_CPU1,
52 	RST_TYPE_FLUSH,
53 	RST_TYPE_HW_DONE,
54 	RST_TYPE_SW_DONE,
55 };
56 
57 struct k230_rst_map {
58 	u32			offset;
59 	enum k230_rst_type	type;
60 	u32			done;
61 	u32			reset;
62 };
63 
64 struct k230_rst {
65 	struct reset_controller_dev	rcdev;
66 	void __iomem			*base;
67 	/* protect register read-modify-write */
68 	spinlock_t			lock;
69 };
70 
71 static const struct k230_rst_map k230_resets[] = {
72 	[RST_CPU0]		= { 0x4,  RST_TYPE_CPU0,    BIT(12), BIT(0) },
73 	[RST_CPU1]		= { 0xc,  RST_TYPE_CPU1,    BIT(12), BIT(0) },
74 	[RST_CPU0_FLUSH]	= { 0x4,  RST_TYPE_FLUSH,   0,       BIT(4) },
75 	[RST_CPU1_FLUSH]	= { 0xc,  RST_TYPE_FLUSH,   0,       BIT(4) },
76 	[RST_AI]		= { 0x14, RST_TYPE_HW_DONE, BIT(31), BIT(0) },
77 	[RST_VPU]		= { 0x1c, RST_TYPE_HW_DONE, BIT(31), BIT(0) },
78 	[RST_HISYS]		= { 0x2c, RST_TYPE_HW_DONE, BIT(4),  BIT(0) },
79 	[RST_HISYS_AHB]		= { 0x2c, RST_TYPE_HW_DONE, BIT(5),  BIT(1) },
80 	[RST_SDIO0]		= { 0x34, RST_TYPE_HW_DONE, BIT(28), BIT(0) },
81 	[RST_SDIO1]		= { 0x34, RST_TYPE_HW_DONE, BIT(29), BIT(1) },
82 	[RST_SDIO_AXI]		= { 0x34, RST_TYPE_HW_DONE, BIT(30), BIT(2) },
83 	[RST_USB0]		= { 0x3c, RST_TYPE_HW_DONE, BIT(28), BIT(0) },
84 	[RST_USB1]		= { 0x3c, RST_TYPE_HW_DONE, BIT(29), BIT(1) },
85 	[RST_USB0_AHB]		= { 0x3c, RST_TYPE_HW_DONE, BIT(30), BIT(0) },
86 	[RST_USB1_AHB]		= { 0x3c, RST_TYPE_HW_DONE, BIT(31), BIT(1) },
87 	[RST_SPI0]		= { 0x44, RST_TYPE_HW_DONE, BIT(28), BIT(0) },
88 	[RST_SPI1]		= { 0x44, RST_TYPE_HW_DONE, BIT(29), BIT(1) },
89 	[RST_SPI2]		= { 0x44, RST_TYPE_HW_DONE, BIT(30), BIT(2) },
90 	[RST_SEC]		= { 0x4c, RST_TYPE_HW_DONE, BIT(31), BIT(0) },
91 	[RST_PDMA]		= { 0x54, RST_TYPE_HW_DONE, BIT(28), BIT(0) },
92 	[RST_SDMA]		= { 0x54, RST_TYPE_HW_DONE, BIT(29), BIT(1) },
93 	[RST_DECOMPRESS]	= { 0x5c, RST_TYPE_HW_DONE, BIT(31), BIT(0) },
94 	[RST_SRAM]		= { 0x64, RST_TYPE_HW_DONE, BIT(28), BIT(0) },
95 	[RST_SHRM_AXIM]		= { 0x64, RST_TYPE_HW_DONE, BIT(30), BIT(2) },
96 	[RST_SHRM_AXIS]		= { 0x64, RST_TYPE_HW_DONE, BIT(31), BIT(3) },
97 	[RST_NONAI2D]		= { 0x6c, RST_TYPE_HW_DONE, BIT(31), BIT(0) },
98 	[RST_MCTL]		= { 0x74, RST_TYPE_HW_DONE, BIT(31), BIT(0) },
99 	[RST_ISP]		= { 0x80, RST_TYPE_HW_DONE, BIT(29), BIT(6) },
100 	[RST_ISP_DW]		= { 0x80, RST_TYPE_HW_DONE, BIT(28), BIT(5) },
101 	[RST_DPU]		= { 0x88, RST_TYPE_HW_DONE, BIT(31), BIT(0) },
102 	[RST_DISP]		= { 0x90, RST_TYPE_HW_DONE, BIT(31), BIT(0) },
103 	[RST_GPU]		= { 0x98, RST_TYPE_HW_DONE, BIT(31), BIT(0) },
104 	[RST_AUDIO]		= { 0xa4, RST_TYPE_HW_DONE, BIT(31), BIT(0) },
105 	[RST_TIMER0]		= { 0x20, RST_TYPE_SW_DONE, 0,       BIT(0) },
106 	[RST_TIMER1]		= { 0x20, RST_TYPE_SW_DONE, 0,       BIT(1) },
107 	[RST_TIMER2]		= { 0x20, RST_TYPE_SW_DONE, 0,       BIT(2) },
108 	[RST_TIMER3]		= { 0x20, RST_TYPE_SW_DONE, 0,       BIT(3) },
109 	[RST_TIMER4]		= { 0x20, RST_TYPE_SW_DONE, 0,       BIT(4) },
110 	[RST_TIMER5]		= { 0x20, RST_TYPE_SW_DONE, 0,       BIT(5) },
111 	[RST_TIMER_APB]		= { 0x20, RST_TYPE_SW_DONE, 0,       BIT(6) },
112 	[RST_HDI]		= { 0x20, RST_TYPE_SW_DONE, 0,       BIT(7) },
113 	[RST_WDT0]		= { 0x20, RST_TYPE_SW_DONE, 0,       BIT(12) },
114 	[RST_WDT1]		= { 0x20, RST_TYPE_SW_DONE, 0,       BIT(13) },
115 	[RST_WDT0_APB]		= { 0x20, RST_TYPE_SW_DONE, 0,       BIT(14) },
116 	[RST_WDT1_APB]		= { 0x20, RST_TYPE_SW_DONE, 0,       BIT(15) },
117 	[RST_TS_APB]		= { 0x20, RST_TYPE_SW_DONE, 0,       BIT(16) },
118 	[RST_MAILBOX]		= { 0x20, RST_TYPE_SW_DONE, 0,       BIT(17) },
119 	[RST_STC]		= { 0x20, RST_TYPE_SW_DONE, 0,       BIT(18) },
120 	[RST_PMU]		= { 0x20, RST_TYPE_SW_DONE, 0,       BIT(19) },
121 	[RST_LOSYS_APB]		= { 0x24, RST_TYPE_SW_DONE, 0,       BIT(0) },
122 	[RST_UART0]		= { 0x24, RST_TYPE_SW_DONE, 0,       BIT(1) },
123 	[RST_UART1]		= { 0x24, RST_TYPE_SW_DONE, 0,       BIT(2) },
124 	[RST_UART2]		= { 0x24, RST_TYPE_SW_DONE, 0,       BIT(3) },
125 	[RST_UART3]		= { 0x24, RST_TYPE_SW_DONE, 0,       BIT(4) },
126 	[RST_UART4]		= { 0x24, RST_TYPE_SW_DONE, 0,       BIT(5) },
127 	[RST_I2C0]		= { 0x24, RST_TYPE_SW_DONE, 0,       BIT(6) },
128 	[RST_I2C1]		= { 0x24, RST_TYPE_SW_DONE, 0,       BIT(7) },
129 	[RST_I2C2]		= { 0x24, RST_TYPE_SW_DONE, 0,       BIT(8) },
130 	[RST_I2C3]		= { 0x24, RST_TYPE_SW_DONE, 0,       BIT(9) },
131 	[RST_I2C4]		= { 0x24, RST_TYPE_SW_DONE, 0,       BIT(10) },
132 	[RST_JAMLINK0_APB]	= { 0x24, RST_TYPE_SW_DONE, 0,       BIT(11) },
133 	[RST_JAMLINK1_APB]	= { 0x24, RST_TYPE_SW_DONE, 0,       BIT(12) },
134 	[RST_JAMLINK2_APB]	= { 0x24, RST_TYPE_SW_DONE, 0,       BIT(13) },
135 	[RST_JAMLINK3_APB]	= { 0x24, RST_TYPE_SW_DONE, 0,       BIT(14) },
136 	[RST_CODEC_APB]		= { 0x24, RST_TYPE_SW_DONE, 0,       BIT(17) },
137 	[RST_GPIO_DB]		= { 0x24, RST_TYPE_SW_DONE, 0,       BIT(18) },
138 	[RST_GPIO_APB]		= { 0x24, RST_TYPE_SW_DONE, 0,       BIT(19) },
139 	[RST_ADC]		= { 0x24, RST_TYPE_SW_DONE, 0,       BIT(20) },
140 	[RST_ADC_APB]		= { 0x24, RST_TYPE_SW_DONE, 0,       BIT(21) },
141 	[RST_PWM_APB]		= { 0x24, RST_TYPE_SW_DONE, 0,       BIT(22) },
142 	[RST_SHRM_APB]		= { 0x64, RST_TYPE_SW_DONE, 0,       BIT(1) },
143 	[RST_CSI0]		= { 0x80, RST_TYPE_SW_DONE, 0,       BIT(0) },
144 	[RST_CSI1]		= { 0x80, RST_TYPE_SW_DONE, 0,       BIT(1) },
145 	[RST_CSI2]		= { 0x80, RST_TYPE_SW_DONE, 0,       BIT(2) },
146 	[RST_CSI_DPHY]		= { 0x80, RST_TYPE_SW_DONE, 0,       BIT(3) },
147 	[RST_ISP_AHB]		= { 0x80, RST_TYPE_SW_DONE, 0,       BIT(4) },
148 	[RST_M0]		= { 0x80, RST_TYPE_SW_DONE, 0,       BIT(7) },
149 	[RST_M1]		= { 0x80, RST_TYPE_SW_DONE, 0,       BIT(8) },
150 	[RST_M2]		= { 0x80, RST_TYPE_SW_DONE, 0,       BIT(9) },
151 	[RST_SPI2AXI]		= { 0xa8, RST_TYPE_SW_DONE, 0,       BIT(0) }
152 };
153 
154 static inline struct k230_rst *to_k230_rst(struct reset_controller_dev *rcdev)
155 {
156 	return container_of(rcdev, struct k230_rst, rcdev);
157 }
158 
159 static void k230_rst_clear_done(struct k230_rst *rstc, unsigned long id,
160 				bool write_en)
161 {
162 	const struct k230_rst_map *rmap = &k230_resets[id];
163 	u32 reg;
164 
165 	guard(spinlock_irqsave)(&rstc->lock);
166 
167 	reg = readl(rstc->base + rmap->offset);
168 	reg |= rmap->done; /* write 1 to clear */
169 	if (write_en)
170 		reg |= rmap->done << 16;
171 	writel(reg, rstc->base + rmap->offset);
172 }
173 
174 static int k230_rst_wait_and_clear_done(struct k230_rst *rstc, unsigned long id,
175 					bool write_en)
176 {
177 	const struct k230_rst_map *rmap = &k230_resets[id];
178 	u32 reg;
179 	int ret;
180 
181 	ret = readl_poll_timeout(rstc->base + rmap->offset, reg,
182 				 reg & rmap->done, 10, 1000);
183 	if (ret) {
184 		dev_err(rstc->rcdev.dev, "Wait for reset done timeout\n");
185 		return ret;
186 	}
187 
188 	k230_rst_clear_done(rstc, id, write_en);
189 
190 	return 0;
191 }
192 
193 static void k230_rst_update(struct k230_rst *rstc, unsigned long id,
194 			    bool assert, bool write_en, bool active_low)
195 {
196 	const struct k230_rst_map *rmap = &k230_resets[id];
197 	u32 reg;
198 
199 	guard(spinlock_irqsave)(&rstc->lock);
200 
201 	reg = readl(rstc->base + rmap->offset);
202 	if (assert ^ active_low)
203 		reg |= rmap->reset;
204 	else
205 		reg &= ~rmap->reset;
206 	if (write_en)
207 		reg |= rmap->reset << 16;
208 	writel(reg, rstc->base + rmap->offset);
209 }
210 
211 static int k230_rst_assert(struct reset_controller_dev *rcdev, unsigned long id)
212 {
213 	struct k230_rst *rstc = to_k230_rst(rcdev);
214 
215 	switch (k230_resets[id].type) {
216 	case RST_TYPE_CPU1:
217 		k230_rst_update(rstc, id, true, true, false);
218 		break;
219 	case RST_TYPE_SW_DONE:
220 		k230_rst_update(rstc, id, true, false,
221 				id == RST_SPI2AXI ? false : true);
222 		break;
223 	case RST_TYPE_CPU0:
224 	case RST_TYPE_FLUSH:
225 	case RST_TYPE_HW_DONE:
226 		return -EOPNOTSUPP;
227 	}
228 
229 	/*
230 	 * The time period when reset is applied but the clock is stopped for
231 	 * RST_TYPE_CPU1 and RST_TYPE_SW_DONE can be set up to 3.75us. Delay
232 	 * 10us to ensure proper reset timing.
233 	 */
234 	udelay(10);
235 
236 	return 0;
237 }
238 
239 static int k230_rst_deassert(struct reset_controller_dev *rcdev,
240 			     unsigned long id)
241 {
242 	struct k230_rst *rstc = to_k230_rst(rcdev);
243 	int ret = 0;
244 
245 	switch (k230_resets[id].type) {
246 	case RST_TYPE_CPU1:
247 		k230_rst_update(rstc, id, false, true, false);
248 		ret = k230_rst_wait_and_clear_done(rstc, id, true);
249 		break;
250 	case RST_TYPE_SW_DONE:
251 		k230_rst_update(rstc, id, false, false,
252 				id == RST_SPI2AXI ? false : true);
253 		break;
254 	case RST_TYPE_CPU0:
255 	case RST_TYPE_FLUSH:
256 	case RST_TYPE_HW_DONE:
257 		return -EOPNOTSUPP;
258 	}
259 
260 	/*
261 	 * The time period when reset is removed but the clock is stopped for
262 	 * RST_TYPE_CPU1 and RST_TYPE_SW_DONE can be set up to 3.75us. Delay
263 	 * 10us to ensure proper reset timing.
264 	 */
265 	udelay(10);
266 
267 	return ret;
268 }
269 
270 static int k230_rst_reset(struct reset_controller_dev *rcdev, unsigned long id)
271 {
272 	struct k230_rst *rstc = to_k230_rst(rcdev);
273 	const struct k230_rst_map *rmap = &k230_resets[id];
274 	u32 reg;
275 	int ret = 0;
276 
277 	switch (rmap->type) {
278 	case RST_TYPE_CPU0:
279 		k230_rst_clear_done(rstc, id, true);
280 		k230_rst_update(rstc, id, true, true, false);
281 		ret = k230_rst_wait_and_clear_done(rstc, id, true);
282 
283 		/*
284 		 * The time period when reset is applied and removed but the
285 		 * clock is stopped for RST_TYPE_CPU0 can be set up to 7.5us.
286 		 * Delay 10us to ensure proper reset timing.
287 		 */
288 		udelay(10);
289 
290 		break;
291 	case RST_TYPE_FLUSH:
292 		k230_rst_update(rstc, id, true, true, false);
293 
294 		/* Wait flush request bit auto cleared by hardware */
295 		ret = readl_poll_timeout(rstc->base + rmap->offset, reg,
296 					!(reg & rmap->reset), 10, 1000);
297 		if (ret)
298 			dev_err(rcdev->dev, "Wait for flush done timeout\n");
299 
300 		break;
301 	case RST_TYPE_HW_DONE:
302 		k230_rst_clear_done(rstc, id, false);
303 		k230_rst_update(rstc, id, true, false, false);
304 		ret = k230_rst_wait_and_clear_done(rstc, id, false);
305 
306 		/*
307 		 * The time period when reset is applied and removed but the
308 		 * clock is stopped for RST_TYPE_HW_DONE can be set up to
309 		 * 127.5us. Delay 200us to ensure proper reset timing.
310 		 */
311 		fsleep(200);
312 
313 		break;
314 	case RST_TYPE_CPU1:
315 	case RST_TYPE_SW_DONE:
316 		k230_rst_assert(rcdev, id);
317 		ret = k230_rst_deassert(rcdev, id);
318 		break;
319 	}
320 
321 	return ret;
322 }
323 
324 static const struct reset_control_ops k230_rst_ops = {
325 	.reset		= k230_rst_reset,
326 	.assert		= k230_rst_assert,
327 	.deassert	= k230_rst_deassert,
328 };
329 
330 static int k230_rst_probe(struct platform_device *pdev)
331 {
332 	struct device *dev = &pdev->dev;
333 	struct k230_rst *rstc;
334 
335 	rstc = devm_kzalloc(dev, sizeof(*rstc), GFP_KERNEL);
336 	if (!rstc)
337 		return -ENOMEM;
338 
339 	rstc->base = devm_platform_ioremap_resource(pdev, 0);
340 	if (IS_ERR(rstc->base))
341 		return PTR_ERR(rstc->base);
342 
343 	spin_lock_init(&rstc->lock);
344 
345 	rstc->rcdev.dev		= dev;
346 	rstc->rcdev.owner	= THIS_MODULE;
347 	rstc->rcdev.ops		= &k230_rst_ops;
348 	rstc->rcdev.nr_resets	= ARRAY_SIZE(k230_resets);
349 	rstc->rcdev.of_node	= dev->of_node;
350 
351 	return devm_reset_controller_register(dev, &rstc->rcdev);
352 }
353 
354 static const struct of_device_id k230_rst_match[] = {
355 	{ .compatible = "canaan,k230-rst", },
356 	{ /* sentinel */ }
357 };
358 MODULE_DEVICE_TABLE(of, k230_rst_match);
359 
360 static struct platform_driver k230_rst_driver = {
361 	.probe = k230_rst_probe,
362 	.driver = {
363 		.name = "k230-rst",
364 		.of_match_table = k230_rst_match,
365 	}
366 };
367 module_platform_driver(k230_rst_driver);
368 
369 MODULE_AUTHOR("Junhui Liu <junhui.liu@pigmoral.tech>");
370 MODULE_DESCRIPTION("Canaan K230 reset driver");
371 MODULE_LICENSE("GPL");
372