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		512U
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 	u32 curr_speed_hz;
111 };
112 
113 static int amlogic_spifc_a1_request(struct amlogic_spifc_a1 *spifc, bool read)
114 {
115 	u32 mask = SPIFC_A1_USER_REQUEST_FINISH |
116 		   (read ? SPIFC_A1_USER_DATA_UPDATED : 0);
117 	u32 val;
118 
119 	writel(SPIFC_A1_USER_REQUEST_ENABLE,
120 	       spifc->base + SPIFC_A1_USER_CTRL0_REG);
121 
122 	return readl_poll_timeout(spifc->base + SPIFC_A1_USER_CTRL0_REG,
123 				  val, (val & mask) == mask, 0,
124 				  200 * USEC_PER_MSEC);
125 }
126 
127 static void amlogic_spifc_a1_drain_buffer(struct amlogic_spifc_a1 *spifc,
128 					  char *buf, u32 len)
129 {
130 	u32 data;
131 	const u32 count = len / sizeof(data);
132 	const u32 pad = len % sizeof(data);
133 
134 	writel(SPIFC_A1_DBUF_AUTO_UPDATE_ADDR,
135 	       spifc->base + SPIFC_A1_DBUF_CTRL_REG);
136 	ioread32_rep(spifc->base + SPIFC_A1_DBUF_DATA_REG, buf, count);
137 
138 	if (pad) {
139 		data = readl(spifc->base + SPIFC_A1_DBUF_DATA_REG);
140 		memcpy(buf + len - pad, &data, pad);
141 	}
142 }
143 
144 static void amlogic_spifc_a1_fill_buffer(struct amlogic_spifc_a1 *spifc,
145 					 const char *buf, u32 len)
146 {
147 	u32 data;
148 	const u32 count = len / sizeof(data);
149 	const u32 pad = len % sizeof(data);
150 
151 	writel(SPIFC_A1_DBUF_DIR | SPIFC_A1_DBUF_AUTO_UPDATE_ADDR,
152 	       spifc->base + SPIFC_A1_DBUF_CTRL_REG);
153 	iowrite32_rep(spifc->base + SPIFC_A1_DBUF_DATA_REG, buf, count);
154 
155 	if (pad) {
156 		memcpy(&data, buf + len - pad, pad);
157 		writel(data, spifc->base + SPIFC_A1_DBUF_DATA_REG);
158 	}
159 }
160 
161 static void amlogic_spifc_a1_user_init(struct amlogic_spifc_a1 *spifc)
162 {
163 	writel(0, spifc->base + SPIFC_A1_USER_CTRL0_REG);
164 	writel(0, spifc->base + SPIFC_A1_USER_CTRL1_REG);
165 	writel(0, spifc->base + SPIFC_A1_USER_CTRL2_REG);
166 	writel(0, spifc->base + SPIFC_A1_USER_CTRL3_REG);
167 }
168 
169 static void amlogic_spifc_a1_set_cmd(struct amlogic_spifc_a1 *spifc,
170 				     u32 cmd_cfg)
171 {
172 	u32 val;
173 
174 	val = readl(spifc->base + SPIFC_A1_USER_CTRL1_REG);
175 	val &= ~(SPIFC_A1_USER_CMD_MODE | SPIFC_A1_USER_CMD_CODE);
176 	val |= cmd_cfg;
177 	writel(val, spifc->base + SPIFC_A1_USER_CTRL1_REG);
178 }
179 
180 static void amlogic_spifc_a1_set_addr(struct amlogic_spifc_a1 *spifc, u32 addr,
181 				      u32 addr_cfg)
182 {
183 	u32 val;
184 
185 	writel(addr, spifc->base + SPIFC_A1_USER_ADDR_REG);
186 
187 	val = readl(spifc->base + SPIFC_A1_USER_CTRL1_REG);
188 	val &= ~(SPIFC_A1_USER_ADDR_MODE | SPIFC_A1_USER_ADDR_BYTES);
189 	val |= addr_cfg;
190 	writel(val, spifc->base + SPIFC_A1_USER_CTRL1_REG);
191 }
192 
193 static void amlogic_spifc_a1_set_dummy(struct amlogic_spifc_a1 *spifc,
194 				       u32 dummy_cfg)
195 {
196 	u32 val = readl(spifc->base + SPIFC_A1_USER_CTRL2_REG);
197 
198 	val &= ~(SPIFC_A1_USER_DUMMY_MODE | SPIFC_A1_USER_DUMMY_CLK_SYCLES);
199 	val |= dummy_cfg;
200 	writel(val, spifc->base + SPIFC_A1_USER_CTRL2_REG);
201 }
202 
203 static int amlogic_spifc_a1_read(struct amlogic_spifc_a1 *spifc, void *buf,
204 				 u32 size, u32 mode)
205 {
206 	u32 val = readl(spifc->base + SPIFC_A1_USER_CTRL3_REG);
207 	int ret;
208 
209 	val &= ~(SPIFC_A1_USER_DIN_MODE | SPIFC_A1_USER_DIN_BYTES);
210 	val |= SPIFC_A1_USER_DIN_ENABLE;
211 	val |= FIELD_PREP(SPIFC_A1_USER_DIN_MODE, mode);
212 	val |= FIELD_PREP(SPIFC_A1_USER_DIN_BYTES, size);
213 	writel(val, spifc->base + SPIFC_A1_USER_CTRL3_REG);
214 
215 	ret = amlogic_spifc_a1_request(spifc, true);
216 	if (!ret)
217 		amlogic_spifc_a1_drain_buffer(spifc, buf, size);
218 
219 	return ret;
220 }
221 
222 static int amlogic_spifc_a1_write(struct amlogic_spifc_a1 *spifc,
223 				  const void *buf, u32 size, u32 mode)
224 {
225 	u32 val;
226 
227 	amlogic_spifc_a1_fill_buffer(spifc, buf, size);
228 
229 	val = readl(spifc->base + SPIFC_A1_USER_CTRL1_REG);
230 	val &= ~(SPIFC_A1_USER_DOUT_MODE | SPIFC_A1_USER_DOUT_BYTES);
231 	val |= FIELD_PREP(SPIFC_A1_USER_DOUT_MODE, mode);
232 	val |= FIELD_PREP(SPIFC_A1_USER_DOUT_BYTES, size);
233 	val |= SPIFC_A1_USER_DOUT_ENABLE;
234 	writel(val, spifc->base + SPIFC_A1_USER_CTRL1_REG);
235 
236 	return amlogic_spifc_a1_request(spifc, false);
237 }
238 
239 static int amlogic_spifc_a1_set_freq(struct amlogic_spifc_a1 *spifc, u32 freq)
240 {
241 	int ret;
242 
243 	if (freq == spifc->curr_speed_hz)
244 		return 0;
245 
246 	ret = clk_set_rate(spifc->clk, freq);
247 	if (ret)
248 		return ret;
249 
250 	spifc->curr_speed_hz = freq;
251 	return 0;
252 }
253 
254 static int amlogic_spifc_a1_exec_op(struct spi_mem *mem,
255 				    const struct spi_mem_op *op)
256 {
257 	struct amlogic_spifc_a1 *spifc =
258 		spi_controller_get_devdata(mem->spi->controller);
259 	size_t data_size = op->data.nbytes;
260 	int ret;
261 
262 	ret = amlogic_spifc_a1_set_freq(spifc, mem->spi->max_speed_hz);
263 	if (ret)
264 		return ret;
265 
266 	amlogic_spifc_a1_user_init(spifc);
267 	amlogic_spifc_a1_set_cmd(spifc, SPIFC_A1_USER_CMD(op));
268 
269 	if (op->addr.nbytes)
270 		amlogic_spifc_a1_set_addr(spifc, op->addr.val,
271 					  SPIFC_A1_USER_ADDR(op));
272 
273 	if (op->dummy.nbytes)
274 		amlogic_spifc_a1_set_dummy(spifc, SPIFC_A1_USER_DUMMY(op));
275 
276 	if (data_size) {
277 		u32 mode = ilog2(op->data.buswidth);
278 
279 		writel(0, spifc->base + SPIFC_A1_USER_DBUF_ADDR_REG);
280 
281 		if (op->data.dir == SPI_MEM_DATA_IN)
282 			ret = amlogic_spifc_a1_read(spifc, op->data.buf.in,
283 						    data_size, mode);
284 		else
285 			ret = amlogic_spifc_a1_write(spifc, op->data.buf.out,
286 						     data_size, mode);
287 	} else {
288 		ret = amlogic_spifc_a1_request(spifc, false);
289 	}
290 
291 	return ret;
292 }
293 
294 static int amlogic_spifc_a1_adjust_op_size(struct spi_mem *mem,
295 					   struct spi_mem_op *op)
296 {
297 	op->data.nbytes = min(op->data.nbytes, SPIFC_A1_BUFFER_SIZE);
298 	return 0;
299 }
300 
301 static void amlogic_spifc_a1_hw_init(struct amlogic_spifc_a1 *spifc)
302 {
303 	u32 regv;
304 
305 	regv = readl(spifc->base + SPIFC_A1_AHB_REQ_CTRL_REG);
306 	regv &= ~(SPIFC_A1_AHB_REQ_ENABLE);
307 	writel(regv, spifc->base + SPIFC_A1_AHB_REQ_CTRL_REG);
308 
309 	regv = readl(spifc->base + SPIFC_A1_AHB_CTRL_REG);
310 	regv &= ~(SPIFC_A1_AHB_BUS_EN);
311 	writel(regv, spifc->base + SPIFC_A1_AHB_CTRL_REG);
312 
313 	writel(SPIFC_A1_ACTIMING0_VAL, spifc->base + SPIFC_A1_ACTIMING0_REG);
314 
315 	writel(0, spifc->base + SPIFC_A1_USER_DBUF_ADDR_REG);
316 }
317 
318 static const struct spi_controller_mem_ops amlogic_spifc_a1_mem_ops = {
319 	.exec_op = amlogic_spifc_a1_exec_op,
320 	.adjust_op_size = amlogic_spifc_a1_adjust_op_size,
321 };
322 
323 static int amlogic_spifc_a1_probe(struct platform_device *pdev)
324 {
325 	struct spi_controller *ctrl;
326 	struct amlogic_spifc_a1 *spifc;
327 	int ret;
328 
329 	ctrl = devm_spi_alloc_host(&pdev->dev, sizeof(*spifc));
330 	if (!ctrl)
331 		return -ENOMEM;
332 
333 	spifc = spi_controller_get_devdata(ctrl);
334 	platform_set_drvdata(pdev, spifc);
335 
336 	spifc->dev = &pdev->dev;
337 	spifc->ctrl = ctrl;
338 
339 	spifc->base = devm_platform_ioremap_resource(pdev, 0);
340 	if (IS_ERR(spifc->base))
341 		return PTR_ERR(spifc->base);
342 
343 	spifc->clk = devm_clk_get_enabled(spifc->dev, NULL);
344 	if (IS_ERR(spifc->clk))
345 		return dev_err_probe(spifc->dev, PTR_ERR(spifc->clk),
346 				     "unable to get clock\n");
347 
348 	amlogic_spifc_a1_hw_init(spifc);
349 
350 	pm_runtime_set_autosuspend_delay(spifc->dev, 500);
351 	pm_runtime_use_autosuspend(spifc->dev);
352 	devm_pm_runtime_enable(spifc->dev);
353 
354 	ctrl->num_chipselect = 1;
355 	ctrl->dev.of_node = pdev->dev.of_node;
356 	ctrl->bits_per_word_mask = SPI_BPW_MASK(8);
357 	ctrl->auto_runtime_pm = true;
358 	ctrl->mem_ops = &amlogic_spifc_a1_mem_ops;
359 	ctrl->min_speed_hz = SPIFC_A1_MIN_HZ;
360 	ctrl->max_speed_hz = SPIFC_A1_MAX_HZ;
361 	ctrl->mode_bits = (SPI_RX_DUAL | SPI_TX_DUAL |
362 			   SPI_RX_QUAD | SPI_TX_QUAD);
363 
364 	ret = devm_spi_register_controller(spifc->dev, ctrl);
365 	if (ret)
366 		return dev_err_probe(spifc->dev, ret,
367 				     "failed to register spi controller\n");
368 
369 	return 0;
370 }
371 
372 #ifdef CONFIG_PM_SLEEP
373 static int amlogic_spifc_a1_suspend(struct device *dev)
374 {
375 	struct amlogic_spifc_a1 *spifc = dev_get_drvdata(dev);
376 	int ret;
377 
378 	ret = spi_controller_suspend(spifc->ctrl);
379 	if (ret)
380 		return ret;
381 
382 	if (!pm_runtime_suspended(dev))
383 		clk_disable_unprepare(spifc->clk);
384 
385 	return 0;
386 }
387 
388 static int amlogic_spifc_a1_resume(struct device *dev)
389 {
390 	struct amlogic_spifc_a1 *spifc = dev_get_drvdata(dev);
391 	int ret = 0;
392 
393 	if (!pm_runtime_suspended(dev)) {
394 		ret = clk_prepare_enable(spifc->clk);
395 		if (ret)
396 			return ret;
397 	}
398 
399 	amlogic_spifc_a1_hw_init(spifc);
400 
401 	ret = spi_controller_resume(spifc->ctrl);
402 	if (ret)
403 		clk_disable_unprepare(spifc->clk);
404 
405 	return ret;
406 }
407 #endif /* CONFIG_PM_SLEEP */
408 
409 #ifdef CONFIG_PM
410 static int amlogic_spifc_a1_runtime_suspend(struct device *dev)
411 {
412 	struct amlogic_spifc_a1 *spifc = dev_get_drvdata(dev);
413 
414 	clk_disable_unprepare(spifc->clk);
415 
416 	return 0;
417 }
418 
419 static int amlogic_spifc_a1_runtime_resume(struct device *dev)
420 {
421 	struct amlogic_spifc_a1 *spifc = dev_get_drvdata(dev);
422 	int ret;
423 
424 	ret = clk_prepare_enable(spifc->clk);
425 	if (!ret)
426 		amlogic_spifc_a1_hw_init(spifc);
427 
428 	return ret;
429 }
430 #endif /* CONFIG_PM */
431 
432 static const struct dev_pm_ops amlogic_spifc_a1_pm_ops = {
433 	SET_SYSTEM_SLEEP_PM_OPS(amlogic_spifc_a1_suspend,
434 				amlogic_spifc_a1_resume)
435 	SET_RUNTIME_PM_OPS(amlogic_spifc_a1_runtime_suspend,
436 			   amlogic_spifc_a1_runtime_resume,
437 			   NULL)
438 };
439 
440 #ifdef CONFIG_OF
441 static const struct of_device_id amlogic_spifc_a1_dt_match[] = {
442 	{ .compatible = "amlogic,a1-spifc", },
443 	{ },
444 };
445 MODULE_DEVICE_TABLE(of, amlogic_spifc_a1_dt_match);
446 #endif /* CONFIG_OF */
447 
448 static struct platform_driver amlogic_spifc_a1_driver = {
449 	.probe	= amlogic_spifc_a1_probe,
450 	.driver	= {
451 		.name		= "amlogic-spifc-a1",
452 		.of_match_table	= of_match_ptr(amlogic_spifc_a1_dt_match),
453 		.pm		= &amlogic_spifc_a1_pm_ops,
454 	},
455 };
456 module_platform_driver(amlogic_spifc_a1_driver);
457 
458 MODULE_AUTHOR("Martin Kurbanov <mmkurbanov@sberdevices.ru>");
459 MODULE_DESCRIPTION("Amlogic A1 SPIFC driver");
460 MODULE_LICENSE("GPL");
461