1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver for Amlogic A1 SPI flash controller (SPIFC)
4  *
5  * Copyright (c) 2023, SberDevices. All Rights Reserved.
6  *
7  * Author: Martin Kurbanov <mmkurbanov@sberdevices.ru>
8  */
9 
10 #include <linux/bitfield.h>
11 #include <linux/clk.h>
12 #include <linux/device.h>
13 #include <linux/io.h>
14 #include <linux/iopoll.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/of.h>
18 #include <linux/platform_device.h>
19 #include <linux/pm_runtime.h>
20 #include <linux/spi/spi.h>
21 #include <linux/spi/spi-mem.h>
22 #include <linux/types.h>
23 
24 #define SPIFC_A1_AHB_CTRL_REG		0x0
25 #define SPIFC_A1_AHB_BUS_EN		BIT(31)
26 
27 #define SPIFC_A1_USER_CTRL0_REG		0x200
28 #define SPIFC_A1_USER_REQUEST_ENABLE	BIT(31)
29 #define SPIFC_A1_USER_REQUEST_FINISH	BIT(30)
30 #define SPIFC_A1_USER_DATA_UPDATED	BIT(0)
31 
32 #define SPIFC_A1_USER_CTRL1_REG		0x204
33 #define SPIFC_A1_USER_CMD_ENABLE	BIT(30)
34 #define SPIFC_A1_USER_CMD_MODE		GENMASK(29, 28)
35 #define SPIFC_A1_USER_CMD_CODE		GENMASK(27, 20)
36 #define SPIFC_A1_USER_ADDR_ENABLE	BIT(19)
37 #define SPIFC_A1_USER_ADDR_MODE		GENMASK(18, 17)
38 #define SPIFC_A1_USER_ADDR_BYTES	GENMASK(16, 15)
39 #define SPIFC_A1_USER_DOUT_ENABLE	BIT(14)
40 #define SPIFC_A1_USER_DOUT_MODE		GENMASK(11, 10)
41 #define SPIFC_A1_USER_DOUT_BYTES	GENMASK(9, 0)
42 
43 #define SPIFC_A1_USER_CTRL2_REG		0x208
44 #define SPIFC_A1_USER_DUMMY_ENABLE	BIT(31)
45 #define SPIFC_A1_USER_DUMMY_MODE	GENMASK(30, 29)
46 #define SPIFC_A1_USER_DUMMY_CLK_SYCLES	GENMASK(28, 23)
47 
48 #define SPIFC_A1_USER_CTRL3_REG		0x20c
49 #define SPIFC_A1_USER_DIN_ENABLE	BIT(31)
50 #define SPIFC_A1_USER_DIN_MODE		GENMASK(28, 27)
51 #define SPIFC_A1_USER_DIN_BYTES		GENMASK(25, 16)
52 
53 #define SPIFC_A1_USER_ADDR_REG		0x210
54 
55 #define SPIFC_A1_AHB_REQ_CTRL_REG	0x214
56 #define SPIFC_A1_AHB_REQ_ENABLE		BIT(31)
57 
58 #define SPIFC_A1_ACTIMING0_REG		(0x0088 << 2)
59 #define SPIFC_A1_TSLCH			GENMASK(31, 30)
60 #define SPIFC_A1_TCLSH			GENMASK(29, 28)
61 #define SPIFC_A1_TSHWL			GENMASK(20, 16)
62 #define SPIFC_A1_TSHSL2			GENMASK(15, 12)
63 #define SPIFC_A1_TSHSL1			GENMASK(11, 8)
64 #define SPIFC_A1_TWHSL			GENMASK(7, 0)
65 
66 #define SPIFC_A1_DBUF_CTRL_REG		0x240
67 #define SPIFC_A1_DBUF_DIR		BIT(31)
68 #define SPIFC_A1_DBUF_AUTO_UPDATE_ADDR	BIT(30)
69 #define SPIFC_A1_DBUF_ADDR		GENMASK(7, 0)
70 
71 #define SPIFC_A1_DBUF_DATA_REG		0x244
72 
73 #define SPIFC_A1_USER_DBUF_ADDR_REG	0x248
74 
75 #define SPIFC_A1_BUFFER_SIZE		512
76 
77 #define SPIFC_A1_MAX_HZ			200000000
78 #define SPIFC_A1_MIN_HZ			1000000
79 
80 #define SPIFC_A1_USER_CMD(op) ( \
81 	SPIFC_A1_USER_CMD_ENABLE | \
82 	FIELD_PREP(SPIFC_A1_USER_CMD_CODE, (op)->cmd.opcode) | \
83 	FIELD_PREP(SPIFC_A1_USER_CMD_MODE, ilog2((op)->cmd.buswidth)))
84 
85 #define SPIFC_A1_USER_ADDR(op) ( \
86 	SPIFC_A1_USER_ADDR_ENABLE | \
87 	FIELD_PREP(SPIFC_A1_USER_ADDR_MODE, ilog2((op)->addr.buswidth)) | \
88 	FIELD_PREP(SPIFC_A1_USER_ADDR_BYTES, (op)->addr.nbytes - 1))
89 
90 #define SPIFC_A1_USER_DUMMY(op) ( \
91 	SPIFC_A1_USER_DUMMY_ENABLE | \
92 	FIELD_PREP(SPIFC_A1_USER_DUMMY_MODE, ilog2((op)->dummy.buswidth)) | \
93 	FIELD_PREP(SPIFC_A1_USER_DUMMY_CLK_SYCLES, (op)->dummy.nbytes << 3))
94 
95 #define SPIFC_A1_TSLCH_VAL	FIELD_PREP(SPIFC_A1_TSLCH, 1)
96 #define SPIFC_A1_TCLSH_VAL	FIELD_PREP(SPIFC_A1_TCLSH, 1)
97 #define SPIFC_A1_TSHWL_VAL	FIELD_PREP(SPIFC_A1_TSHWL, 7)
98 #define SPIFC_A1_TSHSL2_VAL	FIELD_PREP(SPIFC_A1_TSHSL2, 7)
99 #define SPIFC_A1_TSHSL1_VAL	FIELD_PREP(SPIFC_A1_TSHSL1, 7)
100 #define SPIFC_A1_TWHSL_VAL	FIELD_PREP(SPIFC_A1_TWHSL, 2)
101 #define SPIFC_A1_ACTIMING0_VAL	(SPIFC_A1_TSLCH_VAL | SPIFC_A1_TCLSH_VAL | \
102 				 SPIFC_A1_TSHWL_VAL | SPIFC_A1_TSHSL2_VAL | \
103 				 SPIFC_A1_TSHSL1_VAL | SPIFC_A1_TWHSL_VAL)
104 
105 struct amlogic_spifc_a1 {
106 	struct spi_controller *ctrl;
107 	struct clk *clk;
108 	struct device *dev;
109 	void __iomem *base;
110 };
111 
112 static int amlogic_spifc_a1_request(struct amlogic_spifc_a1 *spifc, bool read)
113 {
114 	u32 mask = SPIFC_A1_USER_REQUEST_FINISH |
115 		   (read ? SPIFC_A1_USER_DATA_UPDATED : 0);
116 	u32 val;
117 
118 	writel(SPIFC_A1_USER_REQUEST_ENABLE,
119 	       spifc->base + SPIFC_A1_USER_CTRL0_REG);
120 
121 	return readl_poll_timeout(spifc->base + SPIFC_A1_USER_CTRL0_REG,
122 				  val, (val & mask) == mask, 0,
123 				  200 * USEC_PER_MSEC);
124 }
125 
126 static void amlogic_spifc_a1_drain_buffer(struct amlogic_spifc_a1 *spifc,
127 					  char *buf, u32 len)
128 {
129 	u32 data;
130 	const u32 count = len / sizeof(data);
131 	const u32 pad = len % sizeof(data);
132 
133 	writel(SPIFC_A1_DBUF_AUTO_UPDATE_ADDR,
134 	       spifc->base + SPIFC_A1_DBUF_CTRL_REG);
135 	ioread32_rep(spifc->base + SPIFC_A1_DBUF_DATA_REG, buf, count);
136 
137 	if (pad) {
138 		data = readl(spifc->base + SPIFC_A1_DBUF_DATA_REG);
139 		memcpy(buf + len - pad, &data, pad);
140 	}
141 }
142 
143 static void amlogic_spifc_a1_fill_buffer(struct amlogic_spifc_a1 *spifc,
144 					 const char *buf, u32 len)
145 {
146 	u32 data;
147 	const u32 count = len / sizeof(data);
148 	const u32 pad = len % sizeof(data);
149 
150 	writel(SPIFC_A1_DBUF_DIR | SPIFC_A1_DBUF_AUTO_UPDATE_ADDR,
151 	       spifc->base + SPIFC_A1_DBUF_CTRL_REG);
152 	iowrite32_rep(spifc->base + SPIFC_A1_DBUF_DATA_REG, buf, count);
153 
154 	if (pad) {
155 		memcpy(&data, buf + len - pad, pad);
156 		writel(data, spifc->base + SPIFC_A1_DBUF_DATA_REG);
157 	}
158 }
159 
160 static void amlogic_spifc_a1_user_init(struct amlogic_spifc_a1 *spifc)
161 {
162 	writel(0, spifc->base + SPIFC_A1_USER_CTRL0_REG);
163 	writel(0, spifc->base + SPIFC_A1_USER_CTRL1_REG);
164 	writel(0, spifc->base + SPIFC_A1_USER_CTRL2_REG);
165 	writel(0, spifc->base + SPIFC_A1_USER_CTRL3_REG);
166 }
167 
168 static void amlogic_spifc_a1_set_cmd(struct amlogic_spifc_a1 *spifc,
169 				     u32 cmd_cfg)
170 {
171 	u32 val;
172 
173 	val = readl(spifc->base + SPIFC_A1_USER_CTRL1_REG);
174 	val &= ~(SPIFC_A1_USER_CMD_MODE | SPIFC_A1_USER_CMD_CODE);
175 	val |= cmd_cfg;
176 	writel(val, spifc->base + SPIFC_A1_USER_CTRL1_REG);
177 }
178 
179 static void amlogic_spifc_a1_set_addr(struct amlogic_spifc_a1 *spifc, u32 addr,
180 				      u32 addr_cfg)
181 {
182 	u32 val;
183 
184 	writel(addr, spifc->base + SPIFC_A1_USER_ADDR_REG);
185 
186 	val = readl(spifc->base + SPIFC_A1_USER_CTRL1_REG);
187 	val &= ~(SPIFC_A1_USER_ADDR_MODE | SPIFC_A1_USER_ADDR_BYTES);
188 	val |= addr_cfg;
189 	writel(val, spifc->base + SPIFC_A1_USER_CTRL1_REG);
190 }
191 
192 static void amlogic_spifc_a1_set_dummy(struct amlogic_spifc_a1 *spifc,
193 				       u32 dummy_cfg)
194 {
195 	u32 val = readl(spifc->base + SPIFC_A1_USER_CTRL2_REG);
196 
197 	val &= ~(SPIFC_A1_USER_DUMMY_MODE | SPIFC_A1_USER_DUMMY_CLK_SYCLES);
198 	val |= dummy_cfg;
199 	writel(val, spifc->base + SPIFC_A1_USER_CTRL2_REG);
200 }
201 
202 static int amlogic_spifc_a1_read(struct amlogic_spifc_a1 *spifc, void *buf,
203 				 u32 size, u32 mode)
204 {
205 	u32 val = readl(spifc->base + SPIFC_A1_USER_CTRL3_REG);
206 	int ret;
207 
208 	val &= ~(SPIFC_A1_USER_DIN_MODE | SPIFC_A1_USER_DIN_BYTES);
209 	val |= SPIFC_A1_USER_DIN_ENABLE;
210 	val |= FIELD_PREP(SPIFC_A1_USER_DIN_MODE, mode);
211 	val |= FIELD_PREP(SPIFC_A1_USER_DIN_BYTES, size);
212 	writel(val, spifc->base + SPIFC_A1_USER_CTRL3_REG);
213 
214 	ret = amlogic_spifc_a1_request(spifc, true);
215 	if (!ret)
216 		amlogic_spifc_a1_drain_buffer(spifc, buf, size);
217 
218 	return ret;
219 }
220 
221 static int amlogic_spifc_a1_write(struct amlogic_spifc_a1 *spifc,
222 				  const void *buf, u32 size, u32 mode)
223 {
224 	u32 val;
225 
226 	amlogic_spifc_a1_fill_buffer(spifc, buf, size);
227 
228 	val = readl(spifc->base + SPIFC_A1_USER_CTRL1_REG);
229 	val &= ~(SPIFC_A1_USER_DOUT_MODE | SPIFC_A1_USER_DOUT_BYTES);
230 	val |= FIELD_PREP(SPIFC_A1_USER_DOUT_MODE, mode);
231 	val |= FIELD_PREP(SPIFC_A1_USER_DOUT_BYTES, size);
232 	val |= SPIFC_A1_USER_DOUT_ENABLE;
233 	writel(val, spifc->base + SPIFC_A1_USER_CTRL1_REG);
234 
235 	return amlogic_spifc_a1_request(spifc, false);
236 }
237 
238 static int amlogic_spifc_a1_exec_op(struct spi_mem *mem,
239 				    const struct spi_mem_op *op)
240 {
241 	struct amlogic_spifc_a1 *spifc =
242 		spi_controller_get_devdata(mem->spi->controller);
243 	size_t off, nbytes = op->data.nbytes;
244 	u32 cmd_cfg, addr_cfg, dummy_cfg, dmode;
245 	int ret;
246 
247 	amlogic_spifc_a1_user_init(spifc);
248 
249 	cmd_cfg = SPIFC_A1_USER_CMD(op);
250 	amlogic_spifc_a1_set_cmd(spifc, cmd_cfg);
251 
252 	if (op->addr.nbytes) {
253 		addr_cfg = SPIFC_A1_USER_ADDR(op);
254 		amlogic_spifc_a1_set_addr(spifc, op->addr.val, addr_cfg);
255 	}
256 
257 	if (op->dummy.nbytes) {
258 		dummy_cfg = SPIFC_A1_USER_DUMMY(op);
259 		amlogic_spifc_a1_set_dummy(spifc, dummy_cfg);
260 	}
261 
262 	if (!op->data.nbytes)
263 		return amlogic_spifc_a1_request(spifc, false);
264 
265 	dmode = ilog2(op->data.buswidth);
266 	off = 0;
267 
268 	do {
269 		size_t block_size = min_t(size_t, nbytes, SPIFC_A1_BUFFER_SIZE);
270 
271 		amlogic_spifc_a1_set_cmd(spifc, cmd_cfg);
272 
273 		if (op->addr.nbytes)
274 			amlogic_spifc_a1_set_addr(spifc, op->addr.val + off,
275 						  addr_cfg);
276 
277 		if (op->dummy.nbytes)
278 			amlogic_spifc_a1_set_dummy(spifc, dummy_cfg);
279 
280 		writel(0, spifc->base + SPIFC_A1_USER_DBUF_ADDR_REG);
281 
282 		if (op->data.dir == SPI_MEM_DATA_IN)
283 			ret = amlogic_spifc_a1_read(spifc,
284 						    op->data.buf.in + off,
285 						    block_size, dmode);
286 		else
287 			ret = amlogic_spifc_a1_write(spifc,
288 						     op->data.buf.out + off,
289 						     block_size, dmode);
290 
291 		nbytes -= block_size;
292 		off += block_size;
293 	} while (nbytes != 0 && !ret);
294 
295 	return ret;
296 }
297 
298 static void amlogic_spifc_a1_hw_init(struct amlogic_spifc_a1 *spifc)
299 {
300 	u32 regv;
301 
302 	regv = readl(spifc->base + SPIFC_A1_AHB_REQ_CTRL_REG);
303 	regv &= ~(SPIFC_A1_AHB_REQ_ENABLE);
304 	writel(regv, spifc->base + SPIFC_A1_AHB_REQ_CTRL_REG);
305 
306 	regv = readl(spifc->base + SPIFC_A1_AHB_CTRL_REG);
307 	regv &= ~(SPIFC_A1_AHB_BUS_EN);
308 	writel(regv, spifc->base + SPIFC_A1_AHB_CTRL_REG);
309 
310 	writel(SPIFC_A1_ACTIMING0_VAL, spifc->base + SPIFC_A1_ACTIMING0_REG);
311 
312 	writel(0, spifc->base + SPIFC_A1_USER_DBUF_ADDR_REG);
313 }
314 
315 static const struct spi_controller_mem_ops amlogic_spifc_a1_mem_ops = {
316 	.exec_op = amlogic_spifc_a1_exec_op,
317 };
318 
319 static int amlogic_spifc_a1_probe(struct platform_device *pdev)
320 {
321 	struct spi_controller *ctrl;
322 	struct amlogic_spifc_a1 *spifc;
323 	int ret;
324 
325 	ctrl = devm_spi_alloc_master(&pdev->dev, sizeof(*spifc));
326 	if (!ctrl)
327 		return -ENOMEM;
328 
329 	spifc = spi_controller_get_devdata(ctrl);
330 	platform_set_drvdata(pdev, spifc);
331 
332 	spifc->dev = &pdev->dev;
333 	spifc->ctrl = ctrl;
334 
335 	spifc->base = devm_platform_ioremap_resource(pdev, 0);
336 	if (IS_ERR(spifc->base))
337 		return PTR_ERR(spifc->base);
338 
339 	spifc->clk = devm_clk_get_enabled(spifc->dev, NULL);
340 	if (IS_ERR(spifc->clk))
341 		return dev_err_probe(spifc->dev, PTR_ERR(spifc->clk),
342 				     "unable to get clock\n");
343 
344 	amlogic_spifc_a1_hw_init(spifc);
345 
346 	pm_runtime_set_autosuspend_delay(spifc->dev, 500);
347 	pm_runtime_use_autosuspend(spifc->dev);
348 	devm_pm_runtime_enable(spifc->dev);
349 
350 	ctrl->num_chipselect = 1;
351 	ctrl->dev.of_node = pdev->dev.of_node;
352 	ctrl->bits_per_word_mask = SPI_BPW_MASK(8);
353 	ctrl->auto_runtime_pm = true;
354 	ctrl->mem_ops = &amlogic_spifc_a1_mem_ops;
355 	ctrl->min_speed_hz = SPIFC_A1_MIN_HZ;
356 	ctrl->max_speed_hz = SPIFC_A1_MAX_HZ;
357 	ctrl->mode_bits = (SPI_RX_DUAL | SPI_TX_DUAL |
358 			   SPI_RX_QUAD | SPI_TX_QUAD);
359 
360 	ret = devm_spi_register_controller(spifc->dev, ctrl);
361 	if (ret)
362 		return dev_err_probe(spifc->dev, ret,
363 				     "failed to register spi controller\n");
364 
365 	return 0;
366 }
367 
368 #ifdef CONFIG_PM_SLEEP
369 static int amlogic_spifc_a1_suspend(struct device *dev)
370 {
371 	struct amlogic_spifc_a1 *spifc = dev_get_drvdata(dev);
372 	int ret;
373 
374 	ret = spi_controller_suspend(spifc->ctrl);
375 	if (ret)
376 		return ret;
377 
378 	if (!pm_runtime_suspended(dev))
379 		clk_disable_unprepare(spifc->clk);
380 
381 	return 0;
382 }
383 
384 static int amlogic_spifc_a1_resume(struct device *dev)
385 {
386 	struct amlogic_spifc_a1 *spifc = dev_get_drvdata(dev);
387 	int ret = 0;
388 
389 	if (!pm_runtime_suspended(dev)) {
390 		ret = clk_prepare_enable(spifc->clk);
391 		if (ret)
392 			return ret;
393 	}
394 
395 	amlogic_spifc_a1_hw_init(spifc);
396 
397 	ret = spi_controller_resume(spifc->ctrl);
398 	if (ret)
399 		clk_disable_unprepare(spifc->clk);
400 
401 	return ret;
402 }
403 #endif /* CONFIG_PM_SLEEP */
404 
405 #ifdef CONFIG_PM
406 static int amlogic_spifc_a1_runtime_suspend(struct device *dev)
407 {
408 	struct amlogic_spifc_a1 *spifc = dev_get_drvdata(dev);
409 
410 	clk_disable_unprepare(spifc->clk);
411 
412 	return 0;
413 }
414 
415 static int amlogic_spifc_a1_runtime_resume(struct device *dev)
416 {
417 	struct amlogic_spifc_a1 *spifc = dev_get_drvdata(dev);
418 	int ret;
419 
420 	ret = clk_prepare_enable(spifc->clk);
421 	if (!ret)
422 		amlogic_spifc_a1_hw_init(spifc);
423 
424 	return ret;
425 }
426 #endif /* CONFIG_PM */
427 
428 static const struct dev_pm_ops amlogic_spifc_a1_pm_ops = {
429 	SET_SYSTEM_SLEEP_PM_OPS(amlogic_spifc_a1_suspend,
430 				amlogic_spifc_a1_resume)
431 	SET_RUNTIME_PM_OPS(amlogic_spifc_a1_runtime_suspend,
432 			   amlogic_spifc_a1_runtime_resume,
433 			   NULL)
434 };
435 
436 #ifdef CONFIG_OF
437 static const struct of_device_id amlogic_spifc_a1_dt_match[] = {
438 	{ .compatible = "amlogic,a1-spifc", },
439 	{ },
440 };
441 MODULE_DEVICE_TABLE(of, amlogic_spifc_a1_dt_match);
442 #endif /* CONFIG_OF */
443 
444 static struct platform_driver amlogic_spifc_a1_driver = {
445 	.probe	= amlogic_spifc_a1_probe,
446 	.driver	= {
447 		.name		= "amlogic-spifc-a1",
448 		.of_match_table	= of_match_ptr(amlogic_spifc_a1_dt_match),
449 		.pm		= &amlogic_spifc_a1_pm_ops,
450 	},
451 };
452 module_platform_driver(amlogic_spifc_a1_driver);
453 
454 MODULE_AUTHOR("Martin Kurbanov <mmkurbanov@sberdevices.ru>");
455 MODULE_DESCRIPTION("Amlogic A1 SPIFC driver");
456 MODULE_LICENSE("GPL");
457