summaryrefslogtreecommitdiffstats
path: root/drivers/gpio/gpio-mlxbf2.c
blob: 94d5efce1721c4bf93bc386dffc61274401022eb (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
321
322
323
324
325
326
327
328
329
330
331
332
333
334
// SPDX-License-Identifier: GPL-2.0

#include <linux/acpi.h>
#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/gpio/driver.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/resource.h>
#include <linux/spinlock.h>
#include <linux/types.h>

/*
 * There are 3 YU GPIO blocks:
 * gpio[0]: HOST_GPIO0->HOST_GPIO31
 * gpio[1]: HOST_GPIO32->HOST_GPIO63
 * gpio[2]: HOST_GPIO64->HOST_GPIO69
 */
#define MLXBF2_GPIO_MAX_PINS_PER_BLOCK 32

/*
 * arm_gpio_lock register:
 * bit[31]	lock status: active if set
 * bit[15:0]	set lock
 * The lock is enabled only if 0xd42f is written to this field
 */
#define YU_ARM_GPIO_LOCK_ADDR		0x2801088
#define YU_ARM_GPIO_LOCK_SIZE		0x8
#define YU_LOCK_ACTIVE_BIT(val)		(val >> 31)
#define YU_ARM_GPIO_LOCK_ACQUIRE	0xd42f
#define YU_ARM_GPIO_LOCK_RELEASE	0x0

/*
 * gpio[x] block registers and their offset
 */
#define YU_GPIO_DATAIN			0x04
#define YU_GPIO_MODE1			0x08
#define YU_GPIO_MODE0			0x0c
#define YU_GPIO_DATASET			0x14
#define YU_GPIO_DATACLEAR		0x18
#define YU_GPIO_MODE1_CLEAR		0x50
#define YU_GPIO_MODE0_SET		0x54
#define YU_GPIO_MODE0_CLEAR		0x58

#ifdef CONFIG_PM
struct mlxbf2_gpio_context_save_regs {
	u32 gpio_mode0;
	u32 gpio_mode1;
};
#endif

/* BlueField-2 gpio block context structure. */
struct mlxbf2_gpio_context {
	struct gpio_chip gc;

	/* YU GPIO blocks address */
	void __iomem *gpio_io;

#ifdef CONFIG_PM
	struct mlxbf2_gpio_context_save_regs *csave_regs;
#endif
};

/* BlueField-2 gpio shared structure. */
struct mlxbf2_gpio_param {
	void __iomem *io;
	struct resource *res;
	struct mutex *lock;
};

static struct resource yu_arm_gpio_lock_res = {
	.start = YU_ARM_GPIO_LOCK_ADDR,
	.end   = YU_ARM_GPIO_LOCK_ADDR + YU_ARM_GPIO_LOCK_SIZE - 1,
	.name  = "YU_ARM_GPIO_LOCK",
};

static DEFINE_MUTEX(yu_arm_gpio_lock_mutex);

static struct mlxbf2_gpio_param yu_arm_gpio_lock_param = {
	.res = &yu_arm_gpio_lock_res,
	.lock = &yu_arm_gpio_lock_mutex,
};

/* Request memory region and map yu_arm_gpio_lock resource */
static int mlxbf2_gpio_get_lock_res(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct resource *res;
	resource_size_t size;
	int ret = 0;

	mutex_lock(yu_arm_gpio_lock_param.lock);

	/* Check if the memory map already exists */
	if (yu_arm_gpio_lock_param.io)
		goto exit;

	res = yu_arm_gpio_lock_param.res;
	size = resource_size(res);

	if (!devm_request_mem_region(dev, res->start, size, res->name)) {
		ret = -EFAULT;
		goto exit;
	}

	yu_arm_gpio_lock_param.io = devm_ioremap(dev, res->start, size);
	if (!yu_arm_gpio_lock_param.io)
		ret = -ENOMEM;

exit:
	mutex_unlock(yu_arm_gpio_lock_param.lock);

	return ret;
}

/*
 * Acquire the YU arm_gpio_lock to be able to change the direction
 * mode. If the lock_active bit is already set, return an error.
 */
static int mlxbf2_gpio_lock_acquire(struct mlxbf2_gpio_context *gs)
{
	u32 arm_gpio_lock_val;

	mutex_lock(yu_arm_gpio_lock_param.lock);
	spin_lock(&gs->gc.bgpio_lock);

	arm_gpio_lock_val = readl(yu_arm_gpio_lock_param.io);

	/*
	 * When lock active bit[31] is set, ModeX is write enabled
	 */
	if (YU_LOCK_ACTIVE_BIT(arm_gpio_lock_val)) {
		spin_unlock(&gs->gc.bgpio_lock);
		mutex_unlock(yu_arm_gpio_lock_param.lock);
		return -EINVAL;
	}

	writel(YU_ARM_GPIO_LOCK_ACQUIRE, yu_arm_gpio_lock_param.io);

	return 0;
}

/*
 * Release the YU arm_gpio_lock after changing the direction mode.
 */
static void mlxbf2_gpio_lock_release(struct mlxbf2_gpio_context *gs)
{
	writel(YU_ARM_GPIO_LOCK_RELEASE, yu_arm_gpio_lock_param.io);
	spin_unlock(&gs->gc.bgpio_lock);
	mutex_unlock(yu_arm_gpio_lock_param.lock);
}

/*
 * mode0 and mode1 are both locked by the gpio_lock field.
 *
 * Together, mode0 and mode1 define the gpio Mode dependeing also
 * on Reg_DataOut.
 *
 * {mode1,mode0}:{Reg_DataOut=0,Reg_DataOut=1}->{DataOut=0,DataOut=1}
 *
 * {0,0}:Reg_DataOut{0,1}->{Z,Z} Input PAD
 * {0,1}:Reg_DataOut{0,1}->{0,1} Full drive Output PAD
 * {1,0}:Reg_DataOut{0,1}->{0,Z} 0-set PAD to low, 1-float
 * {1,1}:Reg_DataOut{0,1}->{Z,1} 0-float, 1-set PAD to high
 */

/*
 * Set input direction:
 * {mode1,mode0} = {0,0}
 */
static int mlxbf2_gpio_direction_input(struct gpio_chip *chip,
				       unsigned int offset)
{
	struct mlxbf2_gpio_context *gs = gpiochip_get_data(chip);
	int ret;

	/*
	 * Although the arm_gpio_lock was set in the probe function, check again
	 * if it is still enabled to be able to write to the ModeX registers.
	 */
	ret = mlxbf2_gpio_lock_acquire(gs);
	if (ret < 0)
		return ret;

	writel(BIT(offset), gs->gpio_io + YU_GPIO_MODE0_CLEAR);
	writel(BIT(offset), gs->gpio_io + YU_GPIO_MODE1_CLEAR);

	mlxbf2_gpio_lock_release(gs);

	return ret;
}

/*
 * Set output direction:
 * {mode1,mode0} = {0,1}
 */
static int mlxbf2_gpio_direction_output(struct gpio_chip *chip,
					unsigned int offset,
					int value)
{
	struct mlxbf2_gpio_context *gs = gpiochip_get_data(chip);
	int ret = 0;

	/*
	 * Although the arm_gpio_lock was set in the probe function,
	 * check again it is still enabled to be able to write to the
	 * ModeX registers.
	 */
	ret = mlxbf2_gpio_lock_acquire(gs);
	if (ret < 0)
		return ret;

	writel(BIT(offset), gs->gpio_io + YU_GPIO_MODE1_CLEAR);
	writel(BIT(offset), gs->gpio_io + YU_GPIO_MODE0_SET);

	mlxbf2_gpio_lock_release(gs);

	return ret;
}

/* BlueField-2 GPIO driver initialization routine. */
static int
mlxbf2_gpio_probe(struct platform_device *pdev)
{
	struct mlxbf2_gpio_context *gs;
	struct device *dev = &pdev->dev;
	struct gpio_chip *gc;
	struct resource *res;
	unsigned int npins;
	int ret;

	gs = devm_kzalloc(dev, sizeof(*gs), GFP_KERNEL);
	if (!gs)
		return -ENOMEM;

	/* YU GPIO block address */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res)
		return -ENODEV;

	gs->gpio_io = devm_ioremap(dev, res->start, resource_size(res));
	if (!gs->gpio_io)
		return -ENOMEM;

	ret = mlxbf2_gpio_get_lock_res(pdev);
	if (ret) {
		dev_err(dev, "Failed to get yu_arm_gpio_lock resource\n");
		return ret;
	}

	if (device_property_read_u32(dev, "npins", &npins))
		npins = MLXBF2_GPIO_MAX_PINS_PER_BLOCK;

	gc = &gs->gc;

	ret = bgpio_init(gc, dev, 4,
			gs->gpio_io + YU_GPIO_DATAIN,
			gs->gpio_io + YU_GPIO_DATASET,
			gs->gpio_io + YU_GPIO_DATACLEAR,
			NULL,
			NULL,
			0);

	gc->direction_input = mlxbf2_gpio_direction_input;
	gc->direction_output = mlxbf2_gpio_direction_output;
	gc->ngpio = npins;
	gc->owner = THIS_MODULE;

	platform_set_drvdata(pdev, gs);

	ret = devm_gpiochip_add_data(dev, &gs->gc, gs);
	if (ret) {
		dev_err(dev, "Failed adding memory mapped gpiochip\n");
		return ret;
	}

	return 0;
}

#ifdef CONFIG_PM
static int mlxbf2_gpio_suspend(struct platform_device *pdev,
				pm_message_t state)
{
	struct mlxbf2_gpio_context *gs = platform_get_drvdata(pdev);

	gs->csave_regs->gpio_mode0 = readl(gs->gpio_io +
		YU_GPIO_MODE0);
	gs->csave_regs->gpio_mode1 = readl(gs->gpio_io +
		YU_GPIO_MODE1);

	return 0;
}

static int mlxbf2_gpio_resume(struct platform_device *pdev)
{
	struct mlxbf2_gpio_context *gs = platform_get_drvdata(pdev);

	writel(gs->csave_regs->gpio_mode0, gs->gpio_io +
		YU_GPIO_MODE0);
	writel(gs->csave_regs->gpio_mode1, gs->gpio_io +
		YU_GPIO_MODE1);

	return 0;
}
#endif

static const struct acpi_device_id mlxbf2_gpio_acpi_match[] = {
	{ "MLNXBF22", 0 },
	{},
};
MODULE_DEVICE_TABLE(acpi, mlxbf2_gpio_acpi_match);

static struct platform_driver mlxbf2_gpio_driver = {
	.driver = {
		.name = "mlxbf2_gpio",
		.acpi_match_table = ACPI_PTR(mlxbf2_gpio_acpi_match),
	},
	.probe    = mlxbf2_gpio_probe,
#ifdef CONFIG_PM
	.suspend  = mlxbf2_gpio_suspend,
	.resume   = mlxbf2_gpio_resume,
#endif
};

module_platform_driver(mlxbf2_gpio_driver);

MODULE_DESCRIPTION("Mellanox BlueField-2 GPIO Driver");
MODULE_AUTHOR("Mellanox Technologies");
MODULE_LICENSE("GPL v2");