1  // SPDX-License-Identifier: GPL-2.0
2  // Copyright (C) 2022 Microchip Technology Inc.
3  // pci1xxxx gpio driver
4  
5  #include <linux/module.h>
6  #include <linux/spinlock.h>
7  #include <linux/gpio/driver.h>
8  #include <linux/bio.h>
9  #include <linux/mutex.h>
10  #include <linux/kthread.h>
11  #include <linux/interrupt.h>
12  
13  #include "mchp_pci1xxxx_gp.h"
14  
15  #define PCI1XXXX_NR_PINS		93
16  #define PERI_GEN_RESET			0
17  #define OUT_EN_OFFSET(x)		((((x) / 32) * 4) + 0x400)
18  #define INP_EN_OFFSET(x)		((((x) / 32) * 4) + 0x400 + 0x10)
19  #define OUT_OFFSET(x)			((((x) / 32) * 4) + 0x400 + 0x20)
20  #define INP_OFFSET(x)			((((x) / 32) * 4) + 0x400 + 0x30)
21  #define PULLUP_OFFSET(x)		((((x) / 32) * 4) + 0x400 + 0x40)
22  #define PULLDOWN_OFFSET(x)		((((x) / 32) * 4) + 0x400 + 0x50)
23  #define OPENDRAIN_OFFSET(x)		((((x) / 32) * 4) + 0x400 + 0x60)
24  #define WAKEMASK_OFFSET(x)		((((x) / 32) * 4) + 0x400 + 0x70)
25  #define MODE_OFFSET(x)			((((x) / 32) * 4) + 0x400 + 0x80)
26  #define INTR_LO_TO_HI_EDGE_CONFIG(x)	((((x) / 32) * 4) + 0x400 + 0x90)
27  #define INTR_HI_TO_LO_EDGE_CONFIG(x)	((((x) / 32) * 4) + 0x400 + 0xA0)
28  #define INTR_LEVEL_CONFIG_OFFSET(x)	((((x) / 32) * 4) + 0x400 + 0xB0)
29  #define INTR_LEVEL_MASK_OFFSET(x)	((((x) / 32) * 4) + 0x400 + 0xC0)
30  #define INTR_STAT_OFFSET(x)		((((x) / 32) * 4) + 0x400 + 0xD0)
31  #define DEBOUNCE_OFFSET(x)		((((x) / 32) * 4) + 0x400 + 0xE0)
32  #define PIO_GLOBAL_CONFIG_OFFSET	(0x400 + 0xF0)
33  #define PIO_PCI_CTRL_REG_OFFSET	(0x400 + 0xF4)
34  #define INTR_MASK_OFFSET(x)		((((x) / 32) * 4) + 0x400 + 0x100)
35  #define INTR_STATUS_OFFSET(x)		(((x) * 4) + 0x400 + 0xD0)
36  
37  struct pci1xxxx_gpio {
38  	struct auxiliary_device *aux_dev;
39  	void __iomem *reg_base;
40  	struct gpio_chip gpio;
41  	spinlock_t lock;
42  	int irq_base;
43  };
44  
pci1xxxx_gpio_get_direction(struct gpio_chip * gpio,unsigned int nr)45  static int pci1xxxx_gpio_get_direction(struct gpio_chip *gpio, unsigned int nr)
46  {
47  	struct pci1xxxx_gpio *priv = gpiochip_get_data(gpio);
48  	u32 data;
49  	int ret = -EINVAL;
50  
51  	data = readl(priv->reg_base + INP_EN_OFFSET(nr));
52  	if (data & BIT(nr % 32)) {
53  		ret =  1;
54  	} else {
55  		data = readl(priv->reg_base + OUT_EN_OFFSET(nr));
56  		if (data & BIT(nr % 32))
57  			ret =  0;
58  	}
59  
60  	return ret;
61  }
62  
pci1xxx_assign_bit(void __iomem * base_addr,unsigned int reg_offset,unsigned int bitpos,bool set)63  static inline void pci1xxx_assign_bit(void __iomem *base_addr, unsigned int reg_offset,
64  				      unsigned int bitpos, bool set)
65  {
66  	u32 data;
67  
68  	data = readl(base_addr + reg_offset);
69  	if (set)
70  		data |= BIT(bitpos);
71  	else
72  		data &= ~BIT(bitpos);
73  	writel(data, base_addr + reg_offset);
74  }
75  
pci1xxxx_gpio_direction_input(struct gpio_chip * gpio,unsigned int nr)76  static int pci1xxxx_gpio_direction_input(struct gpio_chip *gpio, unsigned int nr)
77  {
78  	struct pci1xxxx_gpio *priv = gpiochip_get_data(gpio);
79  	unsigned long flags;
80  
81  	spin_lock_irqsave(&priv->lock, flags);
82  	pci1xxx_assign_bit(priv->reg_base, INP_EN_OFFSET(nr), (nr % 32), true);
83  	pci1xxx_assign_bit(priv->reg_base, OUT_EN_OFFSET(nr), (nr % 32), false);
84  	spin_unlock_irqrestore(&priv->lock, flags);
85  
86  	return 0;
87  }
88  
pci1xxxx_gpio_get(struct gpio_chip * gpio,unsigned int nr)89  static int pci1xxxx_gpio_get(struct gpio_chip *gpio, unsigned int nr)
90  {
91  	struct pci1xxxx_gpio *priv = gpiochip_get_data(gpio);
92  
93  	return (readl(priv->reg_base + INP_OFFSET(nr)) >> (nr % 32)) & 1;
94  }
95  
pci1xxxx_gpio_direction_output(struct gpio_chip * gpio,unsigned int nr,int val)96  static int pci1xxxx_gpio_direction_output(struct gpio_chip *gpio,
97  					  unsigned int nr, int val)
98  {
99  	struct pci1xxxx_gpio *priv = gpiochip_get_data(gpio);
100  	unsigned long flags;
101  	u32 data;
102  
103  	spin_lock_irqsave(&priv->lock, flags);
104  	pci1xxx_assign_bit(priv->reg_base, INP_EN_OFFSET(nr), (nr % 32), false);
105  	pci1xxx_assign_bit(priv->reg_base, OUT_EN_OFFSET(nr), (nr % 32), true);
106  	data = readl(priv->reg_base + OUT_OFFSET(nr));
107  	if (val)
108  		data |= (1 << (nr % 32));
109  	else
110  		data &= ~(1 << (nr % 32));
111  	writel(data, priv->reg_base + OUT_OFFSET(nr));
112  	spin_unlock_irqrestore(&priv->lock, flags);
113  
114  	return 0;
115  }
116  
pci1xxxx_gpio_set(struct gpio_chip * gpio,unsigned int nr,int val)117  static void pci1xxxx_gpio_set(struct gpio_chip *gpio,
118  			      unsigned int nr, int val)
119  {
120  	struct pci1xxxx_gpio *priv = gpiochip_get_data(gpio);
121  	unsigned long flags;
122  
123  	spin_lock_irqsave(&priv->lock, flags);
124  	pci1xxx_assign_bit(priv->reg_base, OUT_OFFSET(nr), (nr % 32), val);
125  	spin_unlock_irqrestore(&priv->lock, flags);
126  }
127  
pci1xxxx_gpio_set_config(struct gpio_chip * gpio,unsigned int offset,unsigned long config)128  static int pci1xxxx_gpio_set_config(struct gpio_chip *gpio, unsigned int offset,
129  				    unsigned long config)
130  {
131  	struct pci1xxxx_gpio *priv = gpiochip_get_data(gpio);
132  	unsigned long flags;
133  	int ret = 0;
134  
135  	spin_lock_irqsave(&priv->lock, flags);
136  	switch (pinconf_to_config_param(config)) {
137  	case PIN_CONFIG_BIAS_PULL_UP:
138  		pci1xxx_assign_bit(priv->reg_base, PULLUP_OFFSET(offset), (offset % 32), true);
139  		break;
140  	case PIN_CONFIG_BIAS_PULL_DOWN:
141  		pci1xxx_assign_bit(priv->reg_base, PULLDOWN_OFFSET(offset), (offset % 32), true);
142  		break;
143  	case PIN_CONFIG_BIAS_DISABLE:
144  		pci1xxx_assign_bit(priv->reg_base, PULLUP_OFFSET(offset), (offset % 32), false);
145  		pci1xxx_assign_bit(priv->reg_base, PULLDOWN_OFFSET(offset), (offset % 32), false);
146  		break;
147  	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
148  		pci1xxx_assign_bit(priv->reg_base, OPENDRAIN_OFFSET(offset), (offset % 32), true);
149  		break;
150  	default:
151  		ret = -EOPNOTSUPP;
152  		break;
153  	}
154  	spin_unlock_irqrestore(&priv->lock, flags);
155  
156  	return ret;
157  }
158  
pci1xxxx_gpio_irq_ack(struct irq_data * data)159  static void pci1xxxx_gpio_irq_ack(struct irq_data *data)
160  {
161  	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
162  	struct pci1xxxx_gpio *priv = gpiochip_get_data(chip);
163  	unsigned int gpio = irqd_to_hwirq(data);
164  	unsigned long flags;
165  
166  	spin_lock_irqsave(&priv->lock, flags);
167  	pci1xxx_assign_bit(priv->reg_base, INTR_STAT_OFFSET(gpio), (gpio % 32), true);
168  	spin_unlock_irqrestore(&priv->lock, flags);
169  }
170  
pci1xxxx_gpio_irq_set_mask(struct irq_data * data,bool set)171  static void pci1xxxx_gpio_irq_set_mask(struct irq_data *data, bool set)
172  {
173  	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
174  	struct pci1xxxx_gpio *priv = gpiochip_get_data(chip);
175  	unsigned int gpio = irqd_to_hwirq(data);
176  	unsigned long flags;
177  
178  	if (!set)
179  		gpiochip_enable_irq(chip, gpio);
180  	spin_lock_irqsave(&priv->lock, flags);
181  	pci1xxx_assign_bit(priv->reg_base, INTR_MASK_OFFSET(gpio), (gpio % 32), set);
182  	spin_unlock_irqrestore(&priv->lock, flags);
183  	if (set)
184  		gpiochip_disable_irq(chip, gpio);
185  }
186  
pci1xxxx_gpio_irq_mask(struct irq_data * data)187  static void pci1xxxx_gpio_irq_mask(struct irq_data *data)
188  {
189  	pci1xxxx_gpio_irq_set_mask(data, true);
190  }
191  
pci1xxxx_gpio_irq_unmask(struct irq_data * data)192  static void pci1xxxx_gpio_irq_unmask(struct irq_data *data)
193  {
194  	pci1xxxx_gpio_irq_set_mask(data, false);
195  }
196  
pci1xxxx_gpio_set_type(struct irq_data * data,unsigned int trigger_type)197  static int pci1xxxx_gpio_set_type(struct irq_data *data, unsigned int trigger_type)
198  {
199  	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
200  	struct pci1xxxx_gpio *priv = gpiochip_get_data(chip);
201  	unsigned int gpio = irqd_to_hwirq(data);
202  	unsigned int bitpos = gpio % 32;
203  
204  	if (trigger_type & IRQ_TYPE_EDGE_FALLING) {
205  		pci1xxx_assign_bit(priv->reg_base, INTR_HI_TO_LO_EDGE_CONFIG(gpio),
206  				   bitpos, false);
207  		pci1xxx_assign_bit(priv->reg_base, MODE_OFFSET(gpio),
208  				   bitpos, false);
209  		irq_set_handler_locked(data, handle_edge_irq);
210  	} else {
211  		pci1xxx_assign_bit(priv->reg_base, INTR_HI_TO_LO_EDGE_CONFIG(gpio),
212  				   bitpos, true);
213  	}
214  
215  	if (trigger_type & IRQ_TYPE_EDGE_RISING) {
216  		pci1xxx_assign_bit(priv->reg_base, INTR_LO_TO_HI_EDGE_CONFIG(gpio),
217  				   bitpos, false);
218  		pci1xxx_assign_bit(priv->reg_base, MODE_OFFSET(gpio), bitpos,
219  				   false);
220  		irq_set_handler_locked(data, handle_edge_irq);
221  	} else {
222  		pci1xxx_assign_bit(priv->reg_base, INTR_LO_TO_HI_EDGE_CONFIG(gpio),
223  				   bitpos, true);
224  	}
225  
226  	if (trigger_type & IRQ_TYPE_LEVEL_LOW) {
227  		pci1xxx_assign_bit(priv->reg_base, INTR_LEVEL_CONFIG_OFFSET(gpio),
228  				   bitpos, true);
229  		pci1xxx_assign_bit(priv->reg_base, INTR_LEVEL_MASK_OFFSET(gpio),
230  				   bitpos, false);
231  		pci1xxx_assign_bit(priv->reg_base, MODE_OFFSET(gpio), bitpos,
232  				   true);
233  		irq_set_handler_locked(data, handle_edge_irq);
234  	}
235  
236  	if (trigger_type & IRQ_TYPE_LEVEL_HIGH) {
237  		pci1xxx_assign_bit(priv->reg_base, INTR_LEVEL_CONFIG_OFFSET(gpio),
238  				   bitpos, false);
239  		pci1xxx_assign_bit(priv->reg_base, INTR_LEVEL_MASK_OFFSET(gpio),
240  				   bitpos, false);
241  		pci1xxx_assign_bit(priv->reg_base, MODE_OFFSET(gpio), bitpos,
242  				   true);
243  		irq_set_handler_locked(data, handle_edge_irq);
244  	}
245  
246  	if ((!(trigger_type & IRQ_TYPE_LEVEL_LOW)) && (!(trigger_type & IRQ_TYPE_LEVEL_HIGH)))
247  		pci1xxx_assign_bit(priv->reg_base, INTR_LEVEL_MASK_OFFSET(gpio), bitpos, true);
248  
249  	return true;
250  }
251  
pci1xxxx_gpio_irq_handler(int irq,void * dev_id)252  static irqreturn_t pci1xxxx_gpio_irq_handler(int irq, void *dev_id)
253  {
254  	struct pci1xxxx_gpio *priv = dev_id;
255  	struct gpio_chip *gc =  &priv->gpio;
256  	unsigned long int_status = 0;
257  	unsigned long flags;
258  	u8 pincount;
259  	int bit;
260  	u8 gpiobank;
261  
262  	spin_lock_irqsave(&priv->lock, flags);
263  	pci1xxx_assign_bit(priv->reg_base, PIO_GLOBAL_CONFIG_OFFSET, 16, true);
264  	spin_unlock_irqrestore(&priv->lock, flags);
265  	for (gpiobank = 0; gpiobank < 3; gpiobank++) {
266  		spin_lock_irqsave(&priv->lock, flags);
267  		int_status = readl(priv->reg_base + INTR_STATUS_OFFSET(gpiobank));
268  		spin_unlock_irqrestore(&priv->lock, flags);
269  		if (gpiobank == 2)
270  			pincount = 29;
271  		else
272  			pincount = 32;
273  		for_each_set_bit(bit, &int_status, pincount) {
274  			unsigned int irq;
275  
276  			spin_lock_irqsave(&priv->lock, flags);
277  			writel(BIT(bit), priv->reg_base + INTR_STATUS_OFFSET(gpiobank));
278  			spin_unlock_irqrestore(&priv->lock, flags);
279  			irq = irq_find_mapping(gc->irq.domain, (bit + (gpiobank * 32)));
280  			generic_handle_irq(irq);
281  		}
282  	}
283  	spin_lock_irqsave(&priv->lock, flags);
284  	pci1xxx_assign_bit(priv->reg_base, PIO_GLOBAL_CONFIG_OFFSET, 16, false);
285  	spin_unlock_irqrestore(&priv->lock, flags);
286  
287  	return IRQ_HANDLED;
288  }
289  
290  static const struct irq_chip pci1xxxx_gpio_irqchip = {
291  	.name = "pci1xxxx_gpio",
292  	.irq_ack = pci1xxxx_gpio_irq_ack,
293  	.irq_mask = pci1xxxx_gpio_irq_mask,
294  	.irq_unmask = pci1xxxx_gpio_irq_unmask,
295  	.irq_set_type = pci1xxxx_gpio_set_type,
296  	.flags = IRQCHIP_IMMUTABLE,
297  	GPIOCHIP_IRQ_RESOURCE_HELPERS,
298  };
299  
pci1xxxx_gpio_suspend(struct device * dev)300  static int pci1xxxx_gpio_suspend(struct device *dev)
301  {
302  	struct pci1xxxx_gpio *priv = dev_get_drvdata(dev);
303  	unsigned long flags;
304  
305  	spin_lock_irqsave(&priv->lock, flags);
306  	pci1xxx_assign_bit(priv->reg_base, PIO_GLOBAL_CONFIG_OFFSET,
307  			   16, true);
308  	pci1xxx_assign_bit(priv->reg_base, PIO_GLOBAL_CONFIG_OFFSET,
309  			   17, false);
310  	pci1xxx_assign_bit(priv->reg_base, PERI_GEN_RESET, 16, true);
311  	spin_unlock_irqrestore(&priv->lock, flags);
312  
313  	return 0;
314  }
315  
pci1xxxx_gpio_resume(struct device * dev)316  static int pci1xxxx_gpio_resume(struct device *dev)
317  {
318  	struct pci1xxxx_gpio *priv = dev_get_drvdata(dev);
319  	unsigned long flags;
320  
321  	spin_lock_irqsave(&priv->lock, flags);
322  	pci1xxx_assign_bit(priv->reg_base, PIO_GLOBAL_CONFIG_OFFSET,
323  			   17, true);
324  	pci1xxx_assign_bit(priv->reg_base, PIO_GLOBAL_CONFIG_OFFSET,
325  			   16, false);
326  	pci1xxx_assign_bit(priv->reg_base, PERI_GEN_RESET, 16, false);
327  	spin_unlock_irqrestore(&priv->lock, flags);
328  
329  	return 0;
330  }
331  
pci1xxxx_gpio_setup(struct pci1xxxx_gpio * priv,int irq)332  static int pci1xxxx_gpio_setup(struct pci1xxxx_gpio *priv, int irq)
333  {
334  	struct gpio_chip *gchip = &priv->gpio;
335  	struct gpio_irq_chip *girq;
336  	int retval;
337  
338  	gchip->label = dev_name(&priv->aux_dev->dev);
339  	gchip->parent = &priv->aux_dev->dev;
340  	gchip->owner = THIS_MODULE;
341  	gchip->direction_input = pci1xxxx_gpio_direction_input;
342  	gchip->direction_output = pci1xxxx_gpio_direction_output;
343  	gchip->get_direction = pci1xxxx_gpio_get_direction;
344  	gchip->get = pci1xxxx_gpio_get;
345  	gchip->set = pci1xxxx_gpio_set;
346  	gchip->set_config = pci1xxxx_gpio_set_config;
347  	gchip->dbg_show = NULL;
348  	gchip->base = -1;
349  	gchip->ngpio =  PCI1XXXX_NR_PINS;
350  	gchip->can_sleep = false;
351  
352  	retval = devm_request_threaded_irq(&priv->aux_dev->dev, irq,
353  					   NULL, pci1xxxx_gpio_irq_handler,
354  					   IRQF_ONESHOT, "PCI1xxxxGPIO", priv);
355  
356  	if (retval)
357  		return retval;
358  
359  	girq = &priv->gpio.irq;
360  	gpio_irq_chip_set_chip(girq, &pci1xxxx_gpio_irqchip);
361  	girq->parent_handler = NULL;
362  	girq->num_parents = 0;
363  	girq->parents = NULL;
364  	girq->default_type = IRQ_TYPE_NONE;
365  	girq->handler = handle_bad_irq;
366  
367  	return 0;
368  }
369  
pci1xxxx_gpio_probe(struct auxiliary_device * aux_dev,const struct auxiliary_device_id * id)370  static int pci1xxxx_gpio_probe(struct auxiliary_device *aux_dev,
371  			       const struct auxiliary_device_id *id)
372  
373  {
374  	struct auxiliary_device_wrapper *aux_dev_wrapper;
375  	struct gp_aux_data_type *pdata;
376  	struct pci1xxxx_gpio *priv;
377  	int retval;
378  
379  	aux_dev_wrapper = (struct auxiliary_device_wrapper *)
380  			  container_of(aux_dev, struct auxiliary_device_wrapper, aux_dev);
381  
382  	pdata = &aux_dev_wrapper->gp_aux_data;
383  
384  	if (!pdata)
385  		return -EINVAL;
386  
387  	priv = devm_kzalloc(&aux_dev->dev, sizeof(struct pci1xxxx_gpio), GFP_KERNEL);
388  	if (!priv)
389  		return -ENOMEM;
390  
391  	spin_lock_init(&priv->lock);
392  	priv->aux_dev = aux_dev;
393  
394  	if (!devm_request_mem_region(&aux_dev->dev, pdata->region_start, 0x800, aux_dev->name))
395  		return -EBUSY;
396  
397  	priv->reg_base = devm_ioremap(&aux_dev->dev, pdata->region_start, 0x800);
398  	if (!priv->reg_base)
399  		return -ENOMEM;
400  
401  	writel(0x0264, (priv->reg_base + 0x400 + 0xF0));
402  
403  	retval = pci1xxxx_gpio_setup(priv, pdata->irq_num);
404  
405  	if (retval < 0)
406  		return retval;
407  
408  	dev_set_drvdata(&aux_dev->dev, priv);
409  
410  	return devm_gpiochip_add_data(&aux_dev->dev, &priv->gpio, priv);
411  }
412  
413  static DEFINE_SIMPLE_DEV_PM_OPS(pci1xxxx_gpio_pm_ops, pci1xxxx_gpio_suspend, pci1xxxx_gpio_resume);
414  
415  static const struct auxiliary_device_id pci1xxxx_gpio_auxiliary_id_table[] = {
416  	{.name = "mchp_pci1xxxx_gp.gp_gpio"},
417  	{}
418  };
419  MODULE_DEVICE_TABLE(auxiliary, pci1xxxx_gpio_auxiliary_id_table);
420  
421  static struct auxiliary_driver pci1xxxx_gpio_driver = {
422  	.driver = {
423  		.name = "PCI1xxxxGPIO",
424  		.pm = &pci1xxxx_gpio_pm_ops,
425  		},
426  	.probe = pci1xxxx_gpio_probe,
427  	.id_table = pci1xxxx_gpio_auxiliary_id_table
428  };
429  module_auxiliary_driver(pci1xxxx_gpio_driver);
430  
431  MODULE_DESCRIPTION("Microchip Technology Inc. PCI1xxxx GPIO controller");
432  MODULE_AUTHOR("Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>");
433  MODULE_LICENSE("GPL");
434