1// SPDX-License-Identifier: GPL-2.0
2/*
3 * ARM PL353 SMC driver
4 *
5 * Copyright (C) 2012 - 2018 Xilinx, Inc
6 * Author: Punnaiah Choudary Kalluri <punnaiah@xilinx.com>
7 * Author: Naga Sureshkumar Relli <nagasure@xilinx.com>
8 */
9
10#include <linux/clk.h>
11#include <linux/io.h>
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/of_platform.h>
15#include <linux/platform_device.h>
16#include <linux/slab.h>
17#include <linux/pl353-smc.h>
18#include <linux/amba/bus.h>
19
20/* Register definitions */
21#define PL353_SMC_MEMC_STATUS_OFFS	0	/* Controller status reg, RO */
22#define PL353_SMC_CFG_CLR_OFFS		0xC	/* Clear config reg, WO */
23#define PL353_SMC_DIRECT_CMD_OFFS	0x10	/* Direct command reg, WO */
24#define PL353_SMC_SET_CYCLES_OFFS	0x14	/* Set cycles register, WO */
25#define PL353_SMC_SET_OPMODE_OFFS	0x18	/* Set opmode register, WO */
26#define PL353_SMC_ECC_STATUS_OFFS	0x400	/* ECC status register */
27#define PL353_SMC_ECC_MEMCFG_OFFS	0x404	/* ECC mem config reg */
28#define PL353_SMC_ECC_MEMCMD1_OFFS	0x408	/* ECC mem cmd1 reg */
29#define PL353_SMC_ECC_MEMCMD2_OFFS	0x40C	/* ECC mem cmd2 reg */
30#define PL353_SMC_ECC_VALUE0_OFFS	0x418	/* ECC value 0 reg */
31
32/* Controller status register specific constants */
33#define PL353_SMC_MEMC_STATUS_RAW_INT_1_SHIFT	6
34
35/* Clear configuration register specific constants */
36#define PL353_SMC_CFG_CLR_INT_CLR_1	0x10
37#define PL353_SMC_CFG_CLR_ECC_INT_DIS_1	0x40
38#define PL353_SMC_CFG_CLR_INT_DIS_1	0x2
39#define PL353_SMC_CFG_CLR_DEFAULT_MASK	(PL353_SMC_CFG_CLR_INT_CLR_1 | \
40					 PL353_SMC_CFG_CLR_ECC_INT_DIS_1 | \
41					 PL353_SMC_CFG_CLR_INT_DIS_1)
42
43/* Set cycles register specific constants */
44#define PL353_SMC_SET_CYCLES_T0_MASK	0xF
45#define PL353_SMC_SET_CYCLES_T0_SHIFT	0
46#define PL353_SMC_SET_CYCLES_T1_MASK	0xF
47#define PL353_SMC_SET_CYCLES_T1_SHIFT	4
48#define PL353_SMC_SET_CYCLES_T2_MASK	0x7
49#define PL353_SMC_SET_CYCLES_T2_SHIFT	8
50#define PL353_SMC_SET_CYCLES_T3_MASK	0x7
51#define PL353_SMC_SET_CYCLES_T3_SHIFT	11
52#define PL353_SMC_SET_CYCLES_T4_MASK	0x7
53#define PL353_SMC_SET_CYCLES_T4_SHIFT	14
54#define PL353_SMC_SET_CYCLES_T5_MASK	0x7
55#define PL353_SMC_SET_CYCLES_T5_SHIFT	17
56#define PL353_SMC_SET_CYCLES_T6_MASK	0xF
57#define PL353_SMC_SET_CYCLES_T6_SHIFT	20
58
59/* ECC status register specific constants */
60#define PL353_SMC_ECC_STATUS_BUSY	BIT(6)
61#define PL353_SMC_ECC_REG_SIZE_OFFS	4
62
63/* ECC memory config register specific constants */
64#define PL353_SMC_ECC_MEMCFG_MODE_MASK	0xC
65#define PL353_SMC_ECC_MEMCFG_MODE_SHIFT	2
66#define PL353_SMC_ECC_MEMCFG_PGSIZE_MASK	0x3
67
68#define PL353_SMC_DC_UPT_NAND_REGS	((4 << 23) |	/* CS: NAND chip */ \
69				 (2 << 21))	/* UpdateRegs operation */
70
71#define PL353_NAND_ECC_CMD1	((0x80)       |	/* Write command */ \
72				 (0 << 8)     |	/* Read command */ \
73				 (0x30 << 16) |	/* Read End command */ \
74				 (1 << 24))	/* Read End command calid */
75
76#define PL353_NAND_ECC_CMD2	((0x85)	      |	/* Write col change cmd */ \
77				 (5 << 8)     |	/* Read col change cmd */ \
78				 (0xE0 << 16) |	/* Read col change end cmd */ \
79				 (1 << 24)) /* Read col change end cmd valid */
80#define PL353_NAND_ECC_BUSY_TIMEOUT	(1 * HZ)
81/**
82 * struct pl353_smc_data - Private smc driver structure
83 * @memclk:		Pointer to the peripheral clock
84 * @aclk:		Pointer to the APER clock
85 */
86struct pl353_smc_data {
87	struct clk		*memclk;
88	struct clk		*aclk;
89};
90
91/* SMC virtual register base */
92static void __iomem *pl353_smc_base;
93
94/**
95 * pl353_smc_set_buswidth - Set memory buswidth
96 * @bw: Memory buswidth (8 | 16)
97 * Return: 0 on success or negative errno.
98 */
99int pl353_smc_set_buswidth(unsigned int bw)
100{
101	if (bw != PL353_SMC_MEM_WIDTH_8  && bw != PL353_SMC_MEM_WIDTH_16)
102		return -EINVAL;
103
104	writel(bw, pl353_smc_base + PL353_SMC_SET_OPMODE_OFFS);
105	writel(PL353_SMC_DC_UPT_NAND_REGS, pl353_smc_base +
106	       PL353_SMC_DIRECT_CMD_OFFS);
107
108	return 0;
109}
110EXPORT_SYMBOL_GPL(pl353_smc_set_buswidth);
111
112/**
113 * pl353_smc_set_cycles - Set memory timing parameters
114 * @timings: NAND controller timing parameters
115 *
116 * Sets NAND chip specific timing parameters.
117 */
118void pl353_smc_set_cycles(u32 timings[])
119{
120	/*
121	 * Set write pulse timing. This one is easy to extract:
122	 *
123	 * NWE_PULSE = tWP
124	 */
125	timings[0] &= PL353_SMC_SET_CYCLES_T0_MASK;
126	timings[1] = (timings[1] & PL353_SMC_SET_CYCLES_T1_MASK) <<
127			PL353_SMC_SET_CYCLES_T1_SHIFT;
128	timings[2] = (timings[2]  & PL353_SMC_SET_CYCLES_T2_MASK) <<
129			PL353_SMC_SET_CYCLES_T2_SHIFT;
130	timings[3] = (timings[3]  & PL353_SMC_SET_CYCLES_T3_MASK) <<
131			PL353_SMC_SET_CYCLES_T3_SHIFT;
132	timings[4] = (timings[4] & PL353_SMC_SET_CYCLES_T4_MASK) <<
133			PL353_SMC_SET_CYCLES_T4_SHIFT;
134	timings[5]  = (timings[5]  & PL353_SMC_SET_CYCLES_T5_MASK) <<
135			PL353_SMC_SET_CYCLES_T5_SHIFT;
136	timings[6]  = (timings[6]  & PL353_SMC_SET_CYCLES_T6_MASK) <<
137			PL353_SMC_SET_CYCLES_T6_SHIFT;
138	timings[0] |= timings[1] | timings[2] | timings[3] |
139			timings[4] | timings[5] | timings[6];
140
141	writel(timings[0], pl353_smc_base + PL353_SMC_SET_CYCLES_OFFS);
142	writel(PL353_SMC_DC_UPT_NAND_REGS, pl353_smc_base +
143	       PL353_SMC_DIRECT_CMD_OFFS);
144}
145EXPORT_SYMBOL_GPL(pl353_smc_set_cycles);
146
147/**
148 * pl353_smc_ecc_is_busy - Read ecc busy flag
149 * Return: the ecc_status bit from the ecc_status register. 1 = busy, 0 = idle
150 */
151bool pl353_smc_ecc_is_busy(void)
152{
153	return ((readl(pl353_smc_base + PL353_SMC_ECC_STATUS_OFFS) &
154		  PL353_SMC_ECC_STATUS_BUSY) == PL353_SMC_ECC_STATUS_BUSY);
155}
156EXPORT_SYMBOL_GPL(pl353_smc_ecc_is_busy);
157
158/**
159 * pl353_smc_get_ecc_val - Read ecc_valueN registers
160 * @ecc_reg: Index of the ecc_value reg (0..3)
161 * Return: the content of the requested ecc_value register.
162 *
163 * There are four valid ecc_value registers. The argument is truncated to stay
164 * within this valid boundary.
165 */
166u32 pl353_smc_get_ecc_val(int ecc_reg)
167{
168	u32 addr, reg;
169
170	addr = PL353_SMC_ECC_VALUE0_OFFS +
171		(ecc_reg * PL353_SMC_ECC_REG_SIZE_OFFS);
172	reg = readl(pl353_smc_base + addr);
173
174	return reg;
175}
176EXPORT_SYMBOL_GPL(pl353_smc_get_ecc_val);
177
178/**
179 * pl353_smc_get_nand_int_status_raw - Get NAND interrupt status bit
180 * Return: the raw_int_status1 bit from the memc_status register
181 */
182int pl353_smc_get_nand_int_status_raw(void)
183{
184	u32 reg;
185
186	reg = readl(pl353_smc_base + PL353_SMC_MEMC_STATUS_OFFS);
187	reg >>= PL353_SMC_MEMC_STATUS_RAW_INT_1_SHIFT;
188	reg &= 1;
189
190	return reg;
191}
192EXPORT_SYMBOL_GPL(pl353_smc_get_nand_int_status_raw);
193
194/**
195 * pl353_smc_clr_nand_int - Clear NAND interrupt
196 */
197void pl353_smc_clr_nand_int(void)
198{
199	writel(PL353_SMC_CFG_CLR_INT_CLR_1,
200	       pl353_smc_base + PL353_SMC_CFG_CLR_OFFS);
201}
202EXPORT_SYMBOL_GPL(pl353_smc_clr_nand_int);
203
204/**
205 * pl353_smc_set_ecc_mode - Set SMC ECC mode
206 * @mode: ECC mode (BYPASS, APB, MEM)
207 * Return: 0 on success or negative errno.
208 */
209int pl353_smc_set_ecc_mode(enum pl353_smc_ecc_mode mode)
210{
211	u32 reg;
212	int ret = 0;
213
214	switch (mode) {
215	case PL353_SMC_ECCMODE_BYPASS:
216	case PL353_SMC_ECCMODE_APB:
217	case PL353_SMC_ECCMODE_MEM:
218
219		reg = readl(pl353_smc_base + PL353_SMC_ECC_MEMCFG_OFFS);
220		reg &= ~PL353_SMC_ECC_MEMCFG_MODE_MASK;
221		reg |= mode << PL353_SMC_ECC_MEMCFG_MODE_SHIFT;
222		writel(reg, pl353_smc_base + PL353_SMC_ECC_MEMCFG_OFFS);
223
224		break;
225	default:
226		ret = -EINVAL;
227	}
228
229	return ret;
230}
231EXPORT_SYMBOL_GPL(pl353_smc_set_ecc_mode);
232
233/**
234 * pl353_smc_set_ecc_pg_size - Set SMC ECC page size
235 * @pg_sz: ECC page size
236 * Return: 0 on success or negative errno.
237 */
238int pl353_smc_set_ecc_pg_size(unsigned int pg_sz)
239{
240	u32 reg, sz;
241
242	switch (pg_sz) {
243	case 0:
244		sz = 0;
245		break;
246	case SZ_512:
247		sz = 1;
248		break;
249	case SZ_1K:
250		sz = 2;
251		break;
252	case SZ_2K:
253		sz = 3;
254		break;
255	default:
256		return -EINVAL;
257	}
258
259	reg = readl(pl353_smc_base + PL353_SMC_ECC_MEMCFG_OFFS);
260	reg &= ~PL353_SMC_ECC_MEMCFG_PGSIZE_MASK;
261	reg |= sz;
262	writel(reg, pl353_smc_base + PL353_SMC_ECC_MEMCFG_OFFS);
263
264	return 0;
265}
266EXPORT_SYMBOL_GPL(pl353_smc_set_ecc_pg_size);
267
268static int __maybe_unused pl353_smc_suspend(struct device *dev)
269{
270	struct pl353_smc_data *pl353_smc = dev_get_drvdata(dev);
271
272	clk_disable(pl353_smc->memclk);
273	clk_disable(pl353_smc->aclk);
274
275	return 0;
276}
277
278static int __maybe_unused pl353_smc_resume(struct device *dev)
279{
280	int ret;
281	struct pl353_smc_data *pl353_smc = dev_get_drvdata(dev);
282
283	ret = clk_enable(pl353_smc->aclk);
284	if (ret) {
285		dev_err(dev, "Cannot enable axi domain clock.\n");
286		return ret;
287	}
288
289	ret = clk_enable(pl353_smc->memclk);
290	if (ret) {
291		dev_err(dev, "Cannot enable memory clock.\n");
292		clk_disable(pl353_smc->aclk);
293		return ret;
294	}
295
296	return ret;
297}
298
299static struct amba_driver pl353_smc_driver;
300
301static SIMPLE_DEV_PM_OPS(pl353_smc_dev_pm_ops, pl353_smc_suspend,
302			 pl353_smc_resume);
303
304/**
305 * pl353_smc_init_nand_interface - Initialize the NAND interface
306 * @adev: Pointer to the amba_device struct
307 * @nand_node: Pointer to the pl353_nand device_node struct
308 */
309static void pl353_smc_init_nand_interface(struct amba_device *adev,
310					  struct device_node *nand_node)
311{
312	unsigned long timeout;
313
314	pl353_smc_set_buswidth(PL353_SMC_MEM_WIDTH_8);
315	writel(PL353_SMC_CFG_CLR_INT_CLR_1,
316	       pl353_smc_base + PL353_SMC_CFG_CLR_OFFS);
317	writel(PL353_SMC_DC_UPT_NAND_REGS, pl353_smc_base +
318	       PL353_SMC_DIRECT_CMD_OFFS);
319
320	timeout = jiffies + PL353_NAND_ECC_BUSY_TIMEOUT;
321	/* Wait till the ECC operation is complete */
322	do {
323		if (pl353_smc_ecc_is_busy())
324			cpu_relax();
325		else
326			break;
327	} while (!time_after_eq(jiffies, timeout));
328
329	if (time_after_eq(jiffies, timeout))
330		return;
331
332	writel(PL353_NAND_ECC_CMD1,
333	       pl353_smc_base + PL353_SMC_ECC_MEMCMD1_OFFS);
334	writel(PL353_NAND_ECC_CMD2,
335	       pl353_smc_base + PL353_SMC_ECC_MEMCMD2_OFFS);
336}
337
338static const struct of_device_id pl353_smc_supported_children[] = {
339	{
340		.compatible = "cfi-flash"
341	},
342	{
343		.compatible = "arm,pl353-nand-r2p1",
344		.data = pl353_smc_init_nand_interface
345	},
346	{}
347};
348
349static int pl353_smc_probe(struct amba_device *adev, const struct amba_id *id)
350{
351	struct pl353_smc_data *pl353_smc;
352	struct device_node *child;
353	struct resource *res;
354	int err;
355	struct device_node *of_node = adev->dev.of_node;
356	static void (*init)(struct amba_device *adev,
357			    struct device_node *nand_node);
358	const struct of_device_id *match = NULL;
359
360	pl353_smc = devm_kzalloc(&adev->dev, sizeof(*pl353_smc), GFP_KERNEL);
361	if (!pl353_smc)
362		return -ENOMEM;
363
364	/* Get the NAND controller virtual address */
365	res = &adev->res;
366	pl353_smc_base = devm_ioremap_resource(&adev->dev, res);
367	if (IS_ERR(pl353_smc_base))
368		return PTR_ERR(pl353_smc_base);
369
370	pl353_smc->aclk = devm_clk_get(&adev->dev, "apb_pclk");
371	if (IS_ERR(pl353_smc->aclk)) {
372		dev_err(&adev->dev, "aclk clock not found.\n");
373		return PTR_ERR(pl353_smc->aclk);
374	}
375
376	pl353_smc->memclk = devm_clk_get(&adev->dev, "memclk");
377	if (IS_ERR(pl353_smc->memclk)) {
378		dev_err(&adev->dev, "memclk clock not found.\n");
379		return PTR_ERR(pl353_smc->memclk);
380	}
381
382	err = clk_prepare_enable(pl353_smc->aclk);
383	if (err) {
384		dev_err(&adev->dev, "Unable to enable AXI clock.\n");
385		return err;
386	}
387
388	err = clk_prepare_enable(pl353_smc->memclk);
389	if (err) {
390		dev_err(&adev->dev, "Unable to enable memory clock.\n");
391		goto out_clk_dis_aper;
392	}
393
394	amba_set_drvdata(adev, pl353_smc);
395
396	/* clear interrupts */
397	writel(PL353_SMC_CFG_CLR_DEFAULT_MASK,
398	       pl353_smc_base + PL353_SMC_CFG_CLR_OFFS);
399
400	/* Find compatible children. Only a single child is supported */
401	for_each_available_child_of_node(of_node, child) {
402		match = of_match_node(pl353_smc_supported_children, child);
403		if (!match) {
404			dev_warn(&adev->dev, "unsupported child node\n");
405			continue;
406		}
407		break;
408	}
409	if (!match) {
410		err = -ENODEV;
411		dev_err(&adev->dev, "no matching children\n");
412		goto out_clk_disable;
413	}
414
415	init = match->data;
416	if (init)
417		init(adev, child);
418	of_platform_device_create(child, NULL, &adev->dev);
419	of_node_put(child);
420
421	return 0;
422
423out_clk_disable:
424	clk_disable_unprepare(pl353_smc->memclk);
425out_clk_dis_aper:
426	clk_disable_unprepare(pl353_smc->aclk);
427
428	return err;
429}
430
431static void pl353_smc_remove(struct amba_device *adev)
432{
433	struct pl353_smc_data *pl353_smc = amba_get_drvdata(adev);
434
435	clk_disable_unprepare(pl353_smc->memclk);
436	clk_disable_unprepare(pl353_smc->aclk);
437}
438
439static const struct amba_id pl353_ids[] = {
440	{
441	.id = 0x00041353,
442	.mask = 0x000fffff,
443	},
444	{ 0, 0 },
445};
446MODULE_DEVICE_TABLE(amba, pl353_ids);
447
448static struct amba_driver pl353_smc_driver = {
449	.drv = {
450		.owner = THIS_MODULE,
451		.name = "pl353-smc",
452		.pm = &pl353_smc_dev_pm_ops,
453	},
454	.id_table = pl353_ids,
455	.probe = pl353_smc_probe,
456	.remove = pl353_smc_remove,
457};
458
459module_amba_driver(pl353_smc_driver);
460
461MODULE_AUTHOR("Xilinx, Inc.");
462MODULE_DESCRIPTION("ARM PL353 SMC Driver");
463MODULE_LICENSE("GPL");
464