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v4.6
 
  1/*
  2 * JZ4780 NAND/external memory controller (NEMC)
  3 *
  4 * Copyright (c) 2015 Imagination Technologies
  5 * Author: Alex Smith <alex@alex-smith.me.uk>
  6 *
  7 * This program is free software; you can redistribute it and/or modify it
  8 * under the terms of the GNU General Public License version 2 as published
  9 * by the Free Software Foundation.
 10 */
 11
 12#include <linux/clk.h>
 13#include <linux/init.h>
 
 14#include <linux/math64.h>
 15#include <linux/of.h>
 16#include <linux/of_address.h>
 17#include <linux/of_device.h>
 18#include <linux/of_platform.h>
 19#include <linux/platform_device.h>
 20#include <linux/slab.h>
 21#include <linux/spinlock.h>
 22
 23#include <linux/jz4780-nemc.h>
 24
 25#define NEMC_SMCRn(n)		(0x14 + (((n) - 1) * 4))
 26#define NEMC_NFCSR		0x50
 27
 
 
 28#define NEMC_SMCR_SMT		BIT(0)
 29#define NEMC_SMCR_BW_SHIFT	6
 30#define NEMC_SMCR_BW_MASK	(0x3 << NEMC_SMCR_BW_SHIFT)
 31#define NEMC_SMCR_BW_8		(0 << 6)
 32#define NEMC_SMCR_TAS_SHIFT	8
 33#define NEMC_SMCR_TAS_MASK	(0xf << NEMC_SMCR_TAS_SHIFT)
 34#define NEMC_SMCR_TAH_SHIFT	12
 35#define NEMC_SMCR_TAH_MASK	(0xf << NEMC_SMCR_TAH_SHIFT)
 36#define NEMC_SMCR_TBP_SHIFT	16
 37#define NEMC_SMCR_TBP_MASK	(0xf << NEMC_SMCR_TBP_SHIFT)
 38#define NEMC_SMCR_TAW_SHIFT	20
 39#define NEMC_SMCR_TAW_MASK	(0xf << NEMC_SMCR_TAW_SHIFT)
 40#define NEMC_SMCR_TSTRV_SHIFT	24
 41#define NEMC_SMCR_TSTRV_MASK	(0x3f << NEMC_SMCR_TSTRV_SHIFT)
 42
 43#define NEMC_NFCSR_NFEn(n)	BIT(((n) - 1) << 1)
 44#define NEMC_NFCSR_NFCEn(n)	BIT((((n) - 1) << 1) + 1)
 45#define NEMC_NFCSR_TNFEn(n)	BIT(16 + (n) - 1)
 46
 
 
 
 
 47struct jz4780_nemc {
 48	spinlock_t lock;
 49	struct device *dev;
 
 50	void __iomem *base;
 51	struct clk *clk;
 52	uint32_t clk_period;
 53	unsigned long banks_present;
 54};
 55
 56/**
 57 * jz4780_nemc_num_banks() - count the number of banks referenced by a device
 58 * @dev: device to count banks for, must be a child of the NEMC.
 59 *
 60 * Return: The number of unique NEMC banks referred to by the specified NEMC
 61 * child device. Unique here means that a device that references the same bank
 62 * multiple times in the its "reg" property will only count once.
 63 */
 64unsigned int jz4780_nemc_num_banks(struct device *dev)
 65{
 66	const __be32 *prop;
 67	unsigned int bank, count = 0;
 68	unsigned long referenced = 0;
 69	int i = 0;
 70
 71	while ((prop = of_get_address(dev->of_node, i++, NULL, NULL))) {
 72		bank = of_read_number(prop, 1);
 73		if (!(referenced & BIT(bank))) {
 74			referenced |= BIT(bank);
 75			count++;
 76		}
 77	}
 78
 79	return count;
 80}
 81EXPORT_SYMBOL(jz4780_nemc_num_banks);
 82
 83/**
 84 * jz4780_nemc_set_type() - set the type of device connected to a bank
 85 * @dev: child device of the NEMC.
 86 * @bank: bank number to configure.
 87 * @type: type of device connected to the bank.
 88 */
 89void jz4780_nemc_set_type(struct device *dev, unsigned int bank,
 90			  enum jz4780_nemc_bank_type type)
 91{
 92	struct jz4780_nemc *nemc = dev_get_drvdata(dev->parent);
 93	uint32_t nfcsr;
 94
 95	nfcsr = readl(nemc->base + NEMC_NFCSR);
 96
 97	/* TODO: Support toggle NAND devices. */
 98	switch (type) {
 99	case JZ4780_NEMC_BANK_SRAM:
100		nfcsr &= ~(NEMC_NFCSR_TNFEn(bank) | NEMC_NFCSR_NFEn(bank));
101		break;
102	case JZ4780_NEMC_BANK_NAND:
103		nfcsr &= ~NEMC_NFCSR_TNFEn(bank);
104		nfcsr |= NEMC_NFCSR_NFEn(bank);
105		break;
106	}
107
108	writel(nfcsr, nemc->base + NEMC_NFCSR);
109}
110EXPORT_SYMBOL(jz4780_nemc_set_type);
111
112/**
113 * jz4780_nemc_assert() - (de-)assert a NAND device's chip enable pin
114 * @dev: child device of the NEMC.
115 * @bank: bank number of device.
116 * @assert: whether the chip enable pin should be asserted.
117 *
118 * (De-)asserts the chip enable pin for the NAND device connected to the
119 * specified bank.
120 */
121void jz4780_nemc_assert(struct device *dev, unsigned int bank, bool assert)
122{
123	struct jz4780_nemc *nemc = dev_get_drvdata(dev->parent);
124	uint32_t nfcsr;
125
126	nfcsr = readl(nemc->base + NEMC_NFCSR);
127
128	if (assert)
129		nfcsr |= NEMC_NFCSR_NFCEn(bank);
130	else
131		nfcsr &= ~NEMC_NFCSR_NFCEn(bank);
132
133	writel(nfcsr, nemc->base + NEMC_NFCSR);
134}
135EXPORT_SYMBOL(jz4780_nemc_assert);
136
137static uint32_t jz4780_nemc_clk_period(struct jz4780_nemc *nemc)
138{
139	unsigned long rate;
140
141	rate = clk_get_rate(nemc->clk);
142	if (!rate)
143		return 0;
144
145	/* Return in picoseconds. */
146	return div64_ul(1000000000000ull, rate);
147}
148
149static uint32_t jz4780_nemc_ns_to_cycles(struct jz4780_nemc *nemc, uint32_t ns)
150{
151	return ((ns * 1000) + nemc->clk_period - 1) / nemc->clk_period;
152}
153
154static bool jz4780_nemc_configure_bank(struct jz4780_nemc *nemc,
155				       unsigned int bank,
156				       struct device_node *node)
157{
158	uint32_t smcr, val, cycles;
159
160	/*
161	 * Conversion of tBP and tAW cycle counts to values supported by the
162	 * hardware (round up to the next supported value).
163	 */
164	static const uint32_t convert_tBP_tAW[] = {
165		0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
166
167		/* 11 - 12 -> 12 cycles */
168		11, 11,
169
170		/* 13 - 15 -> 15 cycles */
171		12, 12, 12,
172
173		/* 16 - 20 -> 20 cycles */
174		13, 13, 13, 13, 13,
175
176		/* 21 - 25 -> 25 cycles */
177		14, 14, 14, 14, 14,
178
179		/* 26 - 31 -> 31 cycles */
180		15, 15, 15, 15, 15, 15
181	};
182
183	smcr = readl(nemc->base + NEMC_SMCRn(bank));
184	smcr &= ~NEMC_SMCR_SMT;
185
186	if (!of_property_read_u32(node, "ingenic,nemc-bus-width", &val)) {
187		smcr &= ~NEMC_SMCR_BW_MASK;
188		switch (val) {
189		case 8:
190			smcr |= NEMC_SMCR_BW_8;
191			break;
192		default:
193			/*
194			 * Earlier SoCs support a 16 bit bus width (the 4780
195			 * does not), until those are properly supported, error.
196			 */
197			dev_err(nemc->dev, "unsupported bus width: %u\n", val);
198			return false;
199		}
200	}
201
202	if (of_property_read_u32(node, "ingenic,nemc-tAS", &val) == 0) {
203		smcr &= ~NEMC_SMCR_TAS_MASK;
204		cycles = jz4780_nemc_ns_to_cycles(nemc, val);
205		if (cycles > 15) {
206			dev_err(nemc->dev, "tAS %u is too high (%u cycles)\n",
207				val, cycles);
208			return false;
209		}
210
211		smcr |= cycles << NEMC_SMCR_TAS_SHIFT;
212	}
213
214	if (of_property_read_u32(node, "ingenic,nemc-tAH", &val) == 0) {
215		smcr &= ~NEMC_SMCR_TAH_MASK;
216		cycles = jz4780_nemc_ns_to_cycles(nemc, val);
217		if (cycles > 15) {
218			dev_err(nemc->dev, "tAH %u is too high (%u cycles)\n",
219				val, cycles);
220			return false;
221		}
222
223		smcr |= cycles << NEMC_SMCR_TAH_SHIFT;
224	}
225
226	if (of_property_read_u32(node, "ingenic,nemc-tBP", &val) == 0) {
227		smcr &= ~NEMC_SMCR_TBP_MASK;
228		cycles = jz4780_nemc_ns_to_cycles(nemc, val);
229		if (cycles > 31) {
230			dev_err(nemc->dev, "tBP %u is too high (%u cycles)\n",
231				val, cycles);
232			return false;
233		}
234
235		smcr |= convert_tBP_tAW[cycles] << NEMC_SMCR_TBP_SHIFT;
236	}
237
238	if (of_property_read_u32(node, "ingenic,nemc-tAW", &val) == 0) {
239		smcr &= ~NEMC_SMCR_TAW_MASK;
240		cycles = jz4780_nemc_ns_to_cycles(nemc, val);
241		if (cycles > 31) {
242			dev_err(nemc->dev, "tAW %u is too high (%u cycles)\n",
243				val, cycles);
244			return false;
245		}
246
247		smcr |= convert_tBP_tAW[cycles] << NEMC_SMCR_TAW_SHIFT;
248	}
249
250	if (of_property_read_u32(node, "ingenic,nemc-tSTRV", &val) == 0) {
251		smcr &= ~NEMC_SMCR_TSTRV_MASK;
252		cycles = jz4780_nemc_ns_to_cycles(nemc, val);
253		if (cycles > 63) {
254			dev_err(nemc->dev, "tSTRV %u is too high (%u cycles)\n",
255				val, cycles);
256			return false;
257		}
258
259		smcr |= cycles << NEMC_SMCR_TSTRV_SHIFT;
260	}
261
262	writel(smcr, nemc->base + NEMC_SMCRn(bank));
263	return true;
264}
265
266static int jz4780_nemc_probe(struct platform_device *pdev)
267{
268	struct device *dev = &pdev->dev;
269	struct jz4780_nemc *nemc;
270	struct resource *res;
271	struct device_node *child;
272	const __be32 *prop;
273	unsigned int bank;
274	unsigned long referenced;
275	int i, ret;
276
277	nemc = devm_kzalloc(dev, sizeof(*nemc), GFP_KERNEL);
278	if (!nemc)
279		return -ENOMEM;
280
 
 
 
 
281	spin_lock_init(&nemc->lock);
282	nemc->dev = dev;
283
284	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
285	nemc->base = devm_ioremap_resource(dev, res);
286	if (IS_ERR(nemc->base)) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
287		dev_err(dev, "failed to get I/O memory\n");
288		return PTR_ERR(nemc->base);
289	}
290
291	writel(0, nemc->base + NEMC_NFCSR);
292
293	nemc->clk = devm_clk_get(dev, NULL);
294	if (IS_ERR(nemc->clk)) {
295		dev_err(dev, "failed to get clock\n");
296		return PTR_ERR(nemc->clk);
297	}
298
299	ret = clk_prepare_enable(nemc->clk);
300	if (ret) {
301		dev_err(dev, "failed to enable clock: %d\n", ret);
302		return ret;
303	}
304
305	nemc->clk_period = jz4780_nemc_clk_period(nemc);
306	if (!nemc->clk_period) {
307		dev_err(dev, "failed to calculate clock period\n");
308		clk_disable_unprepare(nemc->clk);
309		return -EINVAL;
310	}
311
312	/*
313	 * Iterate over child devices, check that they do not conflict with
314	 * each other, and register child devices for them. If a child device
315	 * has invalid properties, it is ignored and no platform device is
316	 * registered for it.
317	 */
318	for_each_child_of_node(nemc->dev->of_node, child) {
319		referenced = 0;
320		i = 0;
321		while ((prop = of_get_address(child, i++, NULL, NULL))) {
322			bank = of_read_number(prop, 1);
323			if (bank < 1 || bank >= JZ4780_NEMC_NUM_BANKS) {
324				dev_err(nemc->dev,
325					"%s requests invalid bank %u\n",
326					child->full_name, bank);
327
328				/* Will continue the outer loop below. */
329				referenced = 0;
330				break;
331			}
332
333			referenced |= BIT(bank);
334		}
335
336		if (!referenced) {
337			dev_err(nemc->dev, "%s has no addresses\n",
338				child->full_name);
339			continue;
340		} else if (nemc->banks_present & referenced) {
341			dev_err(nemc->dev, "%s conflicts with another node\n",
342				child->full_name);
343			continue;
344		}
345
346		/* Configure bank parameters. */
347		for_each_set_bit(bank, &referenced, JZ4780_NEMC_NUM_BANKS) {
348			if (!jz4780_nemc_configure_bank(nemc, bank, child)) {
349				referenced = 0;
350				break;
351			}
352		}
353
354		if (referenced) {
355			if (of_platform_device_create(child, NULL, nemc->dev))
356				nemc->banks_present |= referenced;
357		}
358	}
359
360	platform_set_drvdata(pdev, nemc);
361	dev_info(dev, "JZ4780 NEMC initialised\n");
362	return 0;
363}
364
365static int jz4780_nemc_remove(struct platform_device *pdev)
366{
367	struct jz4780_nemc *nemc = platform_get_drvdata(pdev);
368
369	clk_disable_unprepare(nemc->clk);
370	return 0;
371}
372
 
 
 
 
 
 
 
 
373static const struct of_device_id jz4780_nemc_dt_match[] = {
374	{ .compatible = "ingenic,jz4780-nemc" },
 
375	{},
376};
377
378static struct platform_driver jz4780_nemc_driver = {
379	.probe		= jz4780_nemc_probe,
380	.remove		= jz4780_nemc_remove,
381	.driver	= {
382		.name	= "jz4780-nemc",
383		.of_match_table = of_match_ptr(jz4780_nemc_dt_match),
384	},
385};
386
387static int __init jz4780_nemc_init(void)
388{
389	return platform_driver_register(&jz4780_nemc_driver);
390}
391subsys_initcall(jz4780_nemc_init);
v6.13.7
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * JZ4780 NAND/external memory controller (NEMC)
  4 *
  5 * Copyright (c) 2015 Imagination Technologies
  6 * Author: Alex Smith <alex@alex-smith.me.uk>
 
 
 
 
  7 */
  8
  9#include <linux/clk.h>
 10#include <linux/init.h>
 11#include <linux/io.h>
 12#include <linux/math64.h>
 13#include <linux/of.h>
 14#include <linux/of_address.h>
 
 15#include <linux/of_platform.h>
 16#include <linux/platform_device.h>
 17#include <linux/slab.h>
 18#include <linux/spinlock.h>
 19
 20#include <linux/jz4780-nemc.h>
 21
 22#define NEMC_SMCRn(n)		(0x14 + (((n) - 1) * 4))
 23#define NEMC_NFCSR		0x50
 24
 25#define NEMC_REG_LEN		0x54
 26
 27#define NEMC_SMCR_SMT		BIT(0)
 28#define NEMC_SMCR_BW_SHIFT	6
 29#define NEMC_SMCR_BW_MASK	(0x3 << NEMC_SMCR_BW_SHIFT)
 30#define NEMC_SMCR_BW_8		(0 << 6)
 31#define NEMC_SMCR_TAS_SHIFT	8
 32#define NEMC_SMCR_TAS_MASK	(0xf << NEMC_SMCR_TAS_SHIFT)
 33#define NEMC_SMCR_TAH_SHIFT	12
 34#define NEMC_SMCR_TAH_MASK	(0xf << NEMC_SMCR_TAH_SHIFT)
 35#define NEMC_SMCR_TBP_SHIFT	16
 36#define NEMC_SMCR_TBP_MASK	(0xf << NEMC_SMCR_TBP_SHIFT)
 37#define NEMC_SMCR_TAW_SHIFT	20
 38#define NEMC_SMCR_TAW_MASK	(0xf << NEMC_SMCR_TAW_SHIFT)
 39#define NEMC_SMCR_TSTRV_SHIFT	24
 40#define NEMC_SMCR_TSTRV_MASK	(0x3f << NEMC_SMCR_TSTRV_SHIFT)
 41
 42#define NEMC_NFCSR_NFEn(n)	BIT(((n) - 1) << 1)
 43#define NEMC_NFCSR_NFCEn(n)	BIT((((n) - 1) << 1) + 1)
 44#define NEMC_NFCSR_TNFEn(n)	BIT(16 + (n) - 1)
 45
 46struct jz_soc_info {
 47	u8 tas_tah_cycles_max;
 48};
 49
 50struct jz4780_nemc {
 51	spinlock_t lock;
 52	struct device *dev;
 53	const struct jz_soc_info *soc_info;
 54	void __iomem *base;
 55	struct clk *clk;
 56	uint32_t clk_period;
 57	unsigned long banks_present;
 58};
 59
 60/**
 61 * jz4780_nemc_num_banks() - count the number of banks referenced by a device
 62 * @dev: device to count banks for, must be a child of the NEMC.
 63 *
 64 * Return: The number of unique NEMC banks referred to by the specified NEMC
 65 * child device. Unique here means that a device that references the same bank
 66 * multiple times in its "reg" property will only count once.
 67 */
 68unsigned int jz4780_nemc_num_banks(struct device *dev)
 69{
 70	const __be32 *prop;
 71	unsigned int bank, count = 0;
 72	unsigned long referenced = 0;
 73	int i = 0;
 74
 75	while ((prop = of_get_address(dev->of_node, i++, NULL, NULL))) {
 76		bank = of_read_number(prop, 1);
 77		if (!(referenced & BIT(bank))) {
 78			referenced |= BIT(bank);
 79			count++;
 80		}
 81	}
 82
 83	return count;
 84}
 85EXPORT_SYMBOL(jz4780_nemc_num_banks);
 86
 87/**
 88 * jz4780_nemc_set_type() - set the type of device connected to a bank
 89 * @dev: child device of the NEMC.
 90 * @bank: bank number to configure.
 91 * @type: type of device connected to the bank.
 92 */
 93void jz4780_nemc_set_type(struct device *dev, unsigned int bank,
 94			  enum jz4780_nemc_bank_type type)
 95{
 96	struct jz4780_nemc *nemc = dev_get_drvdata(dev->parent);
 97	uint32_t nfcsr;
 98
 99	nfcsr = readl(nemc->base + NEMC_NFCSR);
100
101	/* TODO: Support toggle NAND devices. */
102	switch (type) {
103	case JZ4780_NEMC_BANK_SRAM:
104		nfcsr &= ~(NEMC_NFCSR_TNFEn(bank) | NEMC_NFCSR_NFEn(bank));
105		break;
106	case JZ4780_NEMC_BANK_NAND:
107		nfcsr &= ~NEMC_NFCSR_TNFEn(bank);
108		nfcsr |= NEMC_NFCSR_NFEn(bank);
109		break;
110	}
111
112	writel(nfcsr, nemc->base + NEMC_NFCSR);
113}
114EXPORT_SYMBOL(jz4780_nemc_set_type);
115
116/**
117 * jz4780_nemc_assert() - (de-)assert a NAND device's chip enable pin
118 * @dev: child device of the NEMC.
119 * @bank: bank number of device.
120 * @assert: whether the chip enable pin should be asserted.
121 *
122 * (De-)asserts the chip enable pin for the NAND device connected to the
123 * specified bank.
124 */
125void jz4780_nemc_assert(struct device *dev, unsigned int bank, bool assert)
126{
127	struct jz4780_nemc *nemc = dev_get_drvdata(dev->parent);
128	uint32_t nfcsr;
129
130	nfcsr = readl(nemc->base + NEMC_NFCSR);
131
132	if (assert)
133		nfcsr |= NEMC_NFCSR_NFCEn(bank);
134	else
135		nfcsr &= ~NEMC_NFCSR_NFCEn(bank);
136
137	writel(nfcsr, nemc->base + NEMC_NFCSR);
138}
139EXPORT_SYMBOL(jz4780_nemc_assert);
140
141static uint32_t jz4780_nemc_clk_period(struct jz4780_nemc *nemc)
142{
143	unsigned long rate;
144
145	rate = clk_get_rate(nemc->clk);
146	if (!rate)
147		return 0;
148
149	/* Return in picoseconds. */
150	return div64_ul(1000000000000ull, rate);
151}
152
153static uint32_t jz4780_nemc_ns_to_cycles(struct jz4780_nemc *nemc, uint32_t ns)
154{
155	return ((ns * 1000) + nemc->clk_period - 1) / nemc->clk_period;
156}
157
158static bool jz4780_nemc_configure_bank(struct jz4780_nemc *nemc,
159				       unsigned int bank,
160				       struct device_node *node)
161{
162	uint32_t smcr, val, cycles;
163
164	/*
165	 * Conversion of tBP and tAW cycle counts to values supported by the
166	 * hardware (round up to the next supported value).
167	 */
168	static const u8 convert_tBP_tAW[] = {
169		0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
170
171		/* 11 - 12 -> 12 cycles */
172		11, 11,
173
174		/* 13 - 15 -> 15 cycles */
175		12, 12, 12,
176
177		/* 16 - 20 -> 20 cycles */
178		13, 13, 13, 13, 13,
179
180		/* 21 - 25 -> 25 cycles */
181		14, 14, 14, 14, 14,
182
183		/* 26 - 31 -> 31 cycles */
184		15, 15, 15, 15, 15, 15
185	};
186
187	smcr = readl(nemc->base + NEMC_SMCRn(bank));
188	smcr &= ~NEMC_SMCR_SMT;
189
190	if (!of_property_read_u32(node, "ingenic,nemc-bus-width", &val)) {
191		smcr &= ~NEMC_SMCR_BW_MASK;
192		switch (val) {
193		case 8:
194			smcr |= NEMC_SMCR_BW_8;
195			break;
196		default:
197			/*
198			 * Earlier SoCs support a 16 bit bus width (the 4780
199			 * does not), until those are properly supported, error.
200			 */
201			dev_err(nemc->dev, "unsupported bus width: %u\n", val);
202			return false;
203		}
204	}
205
206	if (of_property_read_u32(node, "ingenic,nemc-tAS", &val) == 0) {
207		smcr &= ~NEMC_SMCR_TAS_MASK;
208		cycles = jz4780_nemc_ns_to_cycles(nemc, val);
209		if (cycles > nemc->soc_info->tas_tah_cycles_max) {
210			dev_err(nemc->dev, "tAS %u is too high (%u cycles)\n",
211				val, cycles);
212			return false;
213		}
214
215		smcr |= cycles << NEMC_SMCR_TAS_SHIFT;
216	}
217
218	if (of_property_read_u32(node, "ingenic,nemc-tAH", &val) == 0) {
219		smcr &= ~NEMC_SMCR_TAH_MASK;
220		cycles = jz4780_nemc_ns_to_cycles(nemc, val);
221		if (cycles > nemc->soc_info->tas_tah_cycles_max) {
222			dev_err(nemc->dev, "tAH %u is too high (%u cycles)\n",
223				val, cycles);
224			return false;
225		}
226
227		smcr |= cycles << NEMC_SMCR_TAH_SHIFT;
228	}
229
230	if (of_property_read_u32(node, "ingenic,nemc-tBP", &val) == 0) {
231		smcr &= ~NEMC_SMCR_TBP_MASK;
232		cycles = jz4780_nemc_ns_to_cycles(nemc, val);
233		if (cycles > 31) {
234			dev_err(nemc->dev, "tBP %u is too high (%u cycles)\n",
235				val, cycles);
236			return false;
237		}
238
239		smcr |= convert_tBP_tAW[cycles] << NEMC_SMCR_TBP_SHIFT;
240	}
241
242	if (of_property_read_u32(node, "ingenic,nemc-tAW", &val) == 0) {
243		smcr &= ~NEMC_SMCR_TAW_MASK;
244		cycles = jz4780_nemc_ns_to_cycles(nemc, val);
245		if (cycles > 31) {
246			dev_err(nemc->dev, "tAW %u is too high (%u cycles)\n",
247				val, cycles);
248			return false;
249		}
250
251		smcr |= convert_tBP_tAW[cycles] << NEMC_SMCR_TAW_SHIFT;
252	}
253
254	if (of_property_read_u32(node, "ingenic,nemc-tSTRV", &val) == 0) {
255		smcr &= ~NEMC_SMCR_TSTRV_MASK;
256		cycles = jz4780_nemc_ns_to_cycles(nemc, val);
257		if (cycles > 63) {
258			dev_err(nemc->dev, "tSTRV %u is too high (%u cycles)\n",
259				val, cycles);
260			return false;
261		}
262
263		smcr |= cycles << NEMC_SMCR_TSTRV_SHIFT;
264	}
265
266	writel(smcr, nemc->base + NEMC_SMCRn(bank));
267	return true;
268}
269
270static int jz4780_nemc_probe(struct platform_device *pdev)
271{
272	struct device *dev = &pdev->dev;
273	struct jz4780_nemc *nemc;
274	struct resource *res;
275	struct device_node *child;
276	const __be32 *prop;
277	unsigned int bank;
278	unsigned long referenced;
279	int i, ret;
280
281	nemc = devm_kzalloc(dev, sizeof(*nemc), GFP_KERNEL);
282	if (!nemc)
283		return -ENOMEM;
284
285	nemc->soc_info = device_get_match_data(dev);
286	if (!nemc->soc_info)
287		return -EINVAL;
288
289	spin_lock_init(&nemc->lock);
290	nemc->dev = dev;
291
292	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
293	if (!res)
294		return -EINVAL;
295
296	/*
297	 * The driver currently only uses the registers up to offset
298	 * NEMC_REG_LEN. Since the EFUSE registers are in the middle of the
299	 * NEMC registers, we only request the registers we will use for now;
300	 * that way the EFUSE driver can probe too.
301	 */
302	if (!devm_request_mem_region(dev, res->start, NEMC_REG_LEN, dev_name(dev))) {
303		dev_err(dev, "unable to request I/O memory region\n");
304		return -EBUSY;
305	}
306
307	nemc->base = devm_ioremap(dev, res->start, NEMC_REG_LEN);
308	if (!nemc->base) {
309		dev_err(dev, "failed to get I/O memory\n");
310		return -ENOMEM;
311	}
312
313	writel(0, nemc->base + NEMC_NFCSR);
314
315	nemc->clk = devm_clk_get(dev, NULL);
316	if (IS_ERR(nemc->clk)) {
317		dev_err(dev, "failed to get clock\n");
318		return PTR_ERR(nemc->clk);
319	}
320
321	ret = clk_prepare_enable(nemc->clk);
322	if (ret) {
323		dev_err(dev, "failed to enable clock: %d\n", ret);
324		return ret;
325	}
326
327	nemc->clk_period = jz4780_nemc_clk_period(nemc);
328	if (!nemc->clk_period) {
329		dev_err(dev, "failed to calculate clock period\n");
330		clk_disable_unprepare(nemc->clk);
331		return -EINVAL;
332	}
333
334	/*
335	 * Iterate over child devices, check that they do not conflict with
336	 * each other, and register child devices for them. If a child device
337	 * has invalid properties, it is ignored and no platform device is
338	 * registered for it.
339	 */
340	for_each_child_of_node(nemc->dev->of_node, child) {
341		referenced = 0;
342		i = 0;
343		while ((prop = of_get_address(child, i++, NULL, NULL))) {
344			bank = of_read_number(prop, 1);
345			if (bank < 1 || bank >= JZ4780_NEMC_NUM_BANKS) {
346				dev_err(nemc->dev,
347					"%pOF requests invalid bank %u\n",
348					child, bank);
349
350				/* Will continue the outer loop below. */
351				referenced = 0;
352				break;
353			}
354
355			referenced |= BIT(bank);
356		}
357
358		if (!referenced) {
359			dev_err(nemc->dev, "%pOF has no addresses\n",
360				child);
361			continue;
362		} else if (nemc->banks_present & referenced) {
363			dev_err(nemc->dev, "%pOF conflicts with another node\n",
364				child);
365			continue;
366		}
367
368		/* Configure bank parameters. */
369		for_each_set_bit(bank, &referenced, JZ4780_NEMC_NUM_BANKS) {
370			if (!jz4780_nemc_configure_bank(nemc, bank, child)) {
371				referenced = 0;
372				break;
373			}
374		}
375
376		if (referenced) {
377			if (of_platform_device_create(child, NULL, nemc->dev))
378				nemc->banks_present |= referenced;
379		}
380	}
381
382	platform_set_drvdata(pdev, nemc);
383	dev_info(dev, "JZ4780 NEMC initialised\n");
384	return 0;
385}
386
387static void jz4780_nemc_remove(struct platform_device *pdev)
388{
389	struct jz4780_nemc *nemc = platform_get_drvdata(pdev);
390
391	clk_disable_unprepare(nemc->clk);
 
392}
393
394static const struct jz_soc_info jz4740_soc_info = {
395	.tas_tah_cycles_max = 7,
396};
397
398static const struct jz_soc_info jz4780_soc_info = {
399	.tas_tah_cycles_max = 15,
400};
401
402static const struct of_device_id jz4780_nemc_dt_match[] = {
403	{ .compatible = "ingenic,jz4740-nemc", .data = &jz4740_soc_info, },
404	{ .compatible = "ingenic,jz4780-nemc", .data = &jz4780_soc_info, },
405	{},
406};
407
408static struct platform_driver jz4780_nemc_driver = {
409	.probe		= jz4780_nemc_probe,
410	.remove		= jz4780_nemc_remove,
411	.driver	= {
412		.name	= "jz4780-nemc",
413		.of_match_table = of_match_ptr(jz4780_nemc_dt_match),
414	},
415};
416
417static int __init jz4780_nemc_init(void)
418{
419	return platform_driver_register(&jz4780_nemc_driver);
420}
421subsys_initcall(jz4780_nemc_init);