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
105struct 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
113static 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
127static 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
144static 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
161static 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
169static 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
180static 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
193static 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
203static 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
222static 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
239static 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
254static 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
294static 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
301static 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
318static 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
323static 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
373static 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
388static 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
410static 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
419static 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
432static 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
441static const struct of_device_id amlogic_spifc_a1_dt_match[] = {
442	{ .compatible = "amlogic,a1-spifc", },
443	{ },
444};
445MODULE_DEVICE_TABLE(of, amlogic_spifc_a1_dt_match);
446#endif /* CONFIG_OF */
447
448static 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};
456module_platform_driver(amlogic_spifc_a1_driver);
457
458MODULE_AUTHOR("Martin Kurbanov <mmkurbanov@sberdevices.ru>");
459MODULE_DESCRIPTION("Amlogic A1 SPIFC driver");
460MODULE_LICENSE("GPL");
461