summaryrefslogtreecommitdiff
path: root/drivers/pinctrl/pinctrl-sti.c
blob: 40341b4eeb756e0ce7725484c0f867d1cfdbfe13 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
/*
 * Pinctrl driver for STMicroelectronics STi SoCs
 *
 *  Copyright (c) 2017
 *  Patrice Chotard <patrice.chotard@st.com>
 *
 * SPDX-License-Identifier:	GPL-2.0
 */

#include <common.h>
#include <bitfield.h>
#include <dm.h>
#include <errno.h>
#include <regmap.h>
#include <syscon.h>
#include <asm/io.h>
#include <dm/pinctrl.h>

DECLARE_GLOBAL_DATA_PTR;

#define MAX_STI_PINCONF_ENTRIES		7
/* Output enable */
#define OE			(1 << 27)
/* Pull Up */
#define PU			(1 << 26)
/* Open Drain */
#define OD			(1 << 25)

/* User-frendly defines for Pin Direction */
		/* oe = 0, pu = 0, od = 0 */
#define IN			(0)
		/* oe = 0, pu = 1, od = 0 */
#define IN_PU			(PU)
		/* oe = 1, pu = 0, od = 0 */
#define OUT			(OE)
		/* oe = 1, pu = 1, od = 0 */
#define OUT_PU			(OE | PU)
		/* oe = 1, pu = 0, od = 1 */
#define BIDIR			(OE | OD)
		/* oe = 1, pu = 1, od = 1 */
#define BIDIR_PU		(OE | PU | OD)

struct sti_pinctrl_platdata {
	struct regmap *regmap;
};

struct sti_pin_desc {
	unsigned char bank;
	unsigned char pin;
	unsigned char alt;
	int dir;
};

/*
 * PIO alternative Function selector
 */
void sti_alternate_select(struct udevice *dev, struct sti_pin_desc *pin_desc)
{
	struct sti_pinctrl_platdata *plat = dev_get_platdata(dev);
	unsigned long sysconf, *sysconfreg;
	int alt = pin_desc->alt;
	int bank = pin_desc->bank;
	int pin = pin_desc->pin;

	sysconfreg = (unsigned long *)plat->regmap->base;

	switch (bank) {
	case 0 ... 5:		/* in "SBC Bank" */
		sysconfreg += bank;
		break;
	case 10 ... 20:		/* in "FRONT Bank" */
		sysconfreg += bank - 10;
		break;
	case 30 ... 35:		/* in "REAR Bank" */
		sysconfreg += bank - 30;
		break;
	case 40 ... 42:		/* in "FLASH Bank" */
		sysconfreg += bank - 40;
		break;
	default:
		BUG();
		return;
	}

	sysconf = readl(sysconfreg);
	sysconf = bitfield_replace(sysconf, pin * 4, 3, alt);
	writel(sysconf, sysconfreg);
}

/* pin configuration */
void sti_pin_configure(struct udevice *dev, struct sti_pin_desc *pin_desc)
{
	struct sti_pinctrl_platdata *plat = dev_get_platdata(dev);
	int bit;
	int oe = 0, pu = 0, od = 0;
	unsigned long *sysconfreg;
	int bank = pin_desc->bank;

	sysconfreg = (unsigned long *)plat->regmap->base + 40;

	/*
	 * NOTE: The PIO configuration for the PIO pins in the
	 * "FLASH Bank" are different from all the other banks!
	 * Specifically, the output-enable pin control register
	 * (SYS_CFG_3040) and the pull-up pin control register
	 * (SYS_CFG_3050), are both classed as being "reserved".
	 * Hence, we do not write to these registers to configure
	 * the OE and PU features for PIOs in this bank. However,
	 * the open-drain pin control register (SYS_CFG_3060)
	 * follows the style of the other banks, and so we can
	 * treat that register normally.
	 *
	 * Being pedantic, we should configure the PU and PD features
	 * in the "FLASH Bank" explicitly instead using the four
	 * SYS_CFG registers: 3080, 3081, 3085, and 3086. However, this
	 * would necessitate passing in the alternate function number
	 * to this function, and adding some horrible complexity here.
	 * Alternatively, we could just perform 4 32-bit "pokes" to
	 * these four SYS_CFG registers early in the initialization.
	 * In practice, these four SYS_CFG registers are correct
	 * after a reset, and U-Boot does not need to change them, so
	 * we (cheat and) rely on these registers being correct.
	 * WARNING: Please be aware of this (pragmatic) behaviour!
	 */
	int flashss = 0;	/* bool: PIO in the Flash Sub-System ? */

	switch (pin_desc->dir) {
	case IN:
		oe = 0; pu = 0; od = 0;
		break;
	case IN_PU:
		oe = 0; pu = 1; od = 0;
		break;
	case OUT:
		oe = 1; pu = 0; od = 0;
		break;
	case BIDIR:
		oe = 1; pu = 0; od = 1;
		break;
	case BIDIR_PU:
		oe = 1; pu = 1; od = 1;
		break;

	default:
		error("%s invalid direction value: 0x%x\n",
		      __func__, pin_desc->dir);
		BUG();
		break;
	}

	switch (bank) {
	case 0 ... 5:		/* in "SBC Bank" */
		sysconfreg += bank / 4;
		break;
	case 10 ... 20:		/* in "FRONT Bank" */
		bank -= 10;
		sysconfreg += bank / 4;
		break;
	case 30 ... 35:		/* in "REAR Bank" */
		bank -= 30;
		sysconfreg += bank / 4;
		break;
	case 40 ... 42:		/* in "FLASH Bank" */
		bank -= 40;
		sysconfreg += bank / 4;
		flashss = 1;	/* pin is in the Flash Sub-System */
		break;
	default:
		BUG();
		return;
	}

	bit = ((bank * 8) + pin_desc->pin) % 32;

	/*
	 * set the "Output Enable" pin control
	 * but, do nothing if in the flashSS
	 */
	if (!flashss) {
		if (oe)
			generic_set_bit(bit, sysconfreg);
		else
			generic_clear_bit(bit, sysconfreg);
	}

	sysconfreg += 10;	/* skip to next set of syscfg registers */

	/*
	 * set the "Pull Up" pin control
	 * but, do nothing if in the FlashSS
	 */

	if (!flashss) {
		if (pu)
			generic_set_bit(bit, sysconfreg);
		else
			generic_clear_bit(bit, sysconfreg);
	}

	sysconfreg += 10;	/* skip to next set of syscfg registers */

	/* set the "Open Drain Enable" pin control */
	if (od)
		generic_set_bit(bit, sysconfreg);
	else
		generic_clear_bit(bit, sysconfreg);
}


static int sti_pinctrl_set_state(struct udevice *dev, struct udevice *config)
{
	struct fdtdec_phandle_args args;
	const void *blob = gd->fdt_blob;
	const char *prop_name;
	int node = dev_of_offset(config);
	int property_offset, prop_len;
	int pinconf_node, ret, count;
	const char *bank_name;
	u32 cells[MAX_STI_PINCONF_ENTRIES];

	struct sti_pin_desc pin_desc;

	/* go to next node "st,pins" which contains the pins configuration */
	pinconf_node = fdt_subnode_offset(blob, node, "st,pins");

	/*
	 * parse each pins configuration which looks like :
	 *	pin_name = <bank_phandle pin_nb alt dir rt_type rt_delay rt_clk>
	 */

	fdt_for_each_property_offset(property_offset, blob, pinconf_node) {
		fdt_getprop_by_offset(blob, property_offset, &prop_name,
				      &prop_len);

		/* extract the bank of the pin description */
		ret = fdtdec_parse_phandle_with_args(blob, pinconf_node,
						     prop_name, "#gpio-cells",
						     0, 0, &args);
		if (ret < 0) {
			error("Can't get the gpio bank phandle: %d\n", ret);
			return ret;
		}

		bank_name = fdt_getprop(blob, args.node, "st,bank-name",
					&count);
		if (count < 0) {
			error("Can't find bank-name property %d\n", count);
			return -EINVAL;
		}

		pin_desc.bank = trailing_strtoln(bank_name, NULL);

		count = fdtdec_get_int_array_count(blob, pinconf_node,
						   prop_name, cells,
						   ARRAY_SIZE(cells));
		if (count < 0) {
			error("Bad pin configuration array %d\n", count);
			return -EINVAL;
		}

		if (count > MAX_STI_PINCONF_ENTRIES) {
			error("Unsupported pinconf array count %d\n", count);
			return -EINVAL;
		}

		pin_desc.pin = cells[1];
		pin_desc.alt = cells[2];
		pin_desc.dir = cells[3];

		sti_alternate_select(dev, &pin_desc);
		sti_pin_configure(dev, &pin_desc);
	};

	return 0;
}

static int sti_pinctrl_probe(struct udevice *dev)
{
	struct sti_pinctrl_platdata *plat = dev_get_platdata(dev);
	struct udevice *syscon;
	int err;

	/* get corresponding syscon phandle */
	err = uclass_get_device_by_phandle(UCLASS_SYSCON, dev,
					   "st,syscfg", &syscon);
	if (err) {
		error("unable to find syscon device\n");
		return err;
	}

	plat->regmap = syscon_get_regmap(syscon);
	if (!plat->regmap) {
		error("unable to find regmap\n");
		return -ENODEV;
	}

	return 0;
}

static const struct udevice_id sti_pinctrl_ids[] = {
	{ .compatible = "st,stih407-sbc-pinctrl" },
	{ .compatible = "st,stih407-front-pinctrl" },
	{ .compatible = "st,stih407-rear-pinctrl" },
	{ .compatible = "st,stih407-flash-pinctrl" },
	{ }
};

const struct pinctrl_ops sti_pinctrl_ops = {
	.set_state = sti_pinctrl_set_state,
};

U_BOOT_DRIVER(pinctrl_sti) = {
	.name = "pinctrl_sti",
	.id = UCLASS_PINCTRL,
	.of_match = sti_pinctrl_ids,
	.ops = &sti_pinctrl_ops,
	.probe = sti_pinctrl_probe,
	.platdata_auto_alloc_size = sizeof(struct sti_pinctrl_platdata),
	.ops = &sti_pinctrl_ops,
};