xref: /openbmc/linux/drivers/memory/pl353-smc.c (revision 6b45fbfa)
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	0xC
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  */
86 struct pl353_smc_data {
87 	struct clk		*memclk;
88 	struct clk		*aclk;
89 };
90 
91 /* SMC virtual register base */
92 static 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  */
99 int 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 }
110 EXPORT_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  */
118 void 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 }
145 EXPORT_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  */
151 bool 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 }
156 EXPORT_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  */
166 u32 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 }
176 EXPORT_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  */
182 int 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 }
192 EXPORT_SYMBOL_GPL(pl353_smc_get_nand_int_status_raw);
193 
194 /**
195  * pl353_smc_clr_nand_int - Clear NAND interrupt
196  */
197 void 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 }
202 EXPORT_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  */
209 int 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 }
231 EXPORT_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  */
238 int 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 }
266 EXPORT_SYMBOL_GPL(pl353_smc_set_ecc_pg_size);
267 
268 static 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 
278 static 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 
299 static struct amba_driver pl353_smc_driver;
300 
301 static 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  */
309 static 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 
338 static 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 
349 static 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 		dev_err(&adev->dev, "no matching children\n");
411 		goto out_clk_disable;
412 	}
413 
414 	init = match->data;
415 	if (init)
416 		init(adev, child);
417 	of_platform_device_create(child, NULL, &adev->dev);
418 
419 	return 0;
420 
421 out_clk_disable:
422 	clk_disable_unprepare(pl353_smc->memclk);
423 out_clk_dis_aper:
424 	clk_disable_unprepare(pl353_smc->aclk);
425 
426 	return err;
427 }
428 
429 static void pl353_smc_remove(struct amba_device *adev)
430 {
431 	struct pl353_smc_data *pl353_smc = amba_get_drvdata(adev);
432 
433 	clk_disable_unprepare(pl353_smc->memclk);
434 	clk_disable_unprepare(pl353_smc->aclk);
435 }
436 
437 static const struct amba_id pl353_ids[] = {
438 	{
439 	.id = 0x00041353,
440 	.mask = 0x000fffff,
441 	},
442 	{ 0, 0 },
443 };
444 MODULE_DEVICE_TABLE(amba, pl353_ids);
445 
446 static struct amba_driver pl353_smc_driver = {
447 	.drv = {
448 		.owner = THIS_MODULE,
449 		.name = "pl353-smc",
450 		.pm = &pl353_smc_dev_pm_ops,
451 	},
452 	.id_table = pl353_ids,
453 	.probe = pl353_smc_probe,
454 	.remove = pl353_smc_remove,
455 };
456 
457 module_amba_driver(pl353_smc_driver);
458 
459 MODULE_AUTHOR("Xilinx, Inc.");
460 MODULE_DESCRIPTION("ARM PL353 SMC Driver");
461 MODULE_LICENSE("GPL");
462