1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * TQ-Systems TQMx86 PLD GPIO driver
4 *
5 * Based on vendor driver by:
6 * Vadim V.Vlasov <vvlasov@dev.rtsoft.ru>
7 */
8
9 #include <linux/bitops.h>
10 #include <linux/errno.h>
11 #include <linux/gpio/driver.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/platform_device.h>
17 #include <linux/pm_runtime.h>
18 #include <linux/slab.h>
19
20 #define TQMX86_NGPIO 8
21 #define TQMX86_NGPO 4 /* 0-3 - output */
22 #define TQMX86_NGPI 4 /* 4-7 - input */
23 #define TQMX86_DIR_INPUT_MASK 0xf0 /* 0-3 - output, 4-7 - input */
24
25 #define TQMX86_GPIODD 0 /* GPIO Data Direction Register */
26 #define TQMX86_GPIOD 1 /* GPIO Data Register */
27 #define TQMX86_GPIIC 3 /* GPI Interrupt Configuration Register */
28 #define TQMX86_GPIIS 4 /* GPI Interrupt Status Register */
29
30 #define TQMX86_GPII_FALLING BIT(0)
31 #define TQMX86_GPII_RISING BIT(1)
32 #define TQMX86_GPII_MASK (BIT(0) | BIT(1))
33 #define TQMX86_GPII_BITS 2
34
35 struct tqmx86_gpio_data {
36 struct gpio_chip chip;
37 struct irq_chip irq_chip;
38 void __iomem *io_base;
39 int irq;
40 raw_spinlock_t spinlock;
41 u8 irq_type[TQMX86_NGPI];
42 };
43
tqmx86_gpio_read(struct tqmx86_gpio_data * gd,unsigned int reg)44 static u8 tqmx86_gpio_read(struct tqmx86_gpio_data *gd, unsigned int reg)
45 {
46 return ioread8(gd->io_base + reg);
47 }
48
tqmx86_gpio_write(struct tqmx86_gpio_data * gd,u8 val,unsigned int reg)49 static void tqmx86_gpio_write(struct tqmx86_gpio_data *gd, u8 val,
50 unsigned int reg)
51 {
52 iowrite8(val, gd->io_base + reg);
53 }
54
tqmx86_gpio_get(struct gpio_chip * chip,unsigned int offset)55 static int tqmx86_gpio_get(struct gpio_chip *chip, unsigned int offset)
56 {
57 struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip);
58
59 return !!(tqmx86_gpio_read(gpio, TQMX86_GPIOD) & BIT(offset));
60 }
61
tqmx86_gpio_set(struct gpio_chip * chip,unsigned int offset,int value)62 static void tqmx86_gpio_set(struct gpio_chip *chip, unsigned int offset,
63 int value)
64 {
65 struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip);
66 unsigned long flags;
67 u8 val;
68
69 raw_spin_lock_irqsave(&gpio->spinlock, flags);
70 val = tqmx86_gpio_read(gpio, TQMX86_GPIOD);
71 if (value)
72 val |= BIT(offset);
73 else
74 val &= ~BIT(offset);
75 tqmx86_gpio_write(gpio, val, TQMX86_GPIOD);
76 raw_spin_unlock_irqrestore(&gpio->spinlock, flags);
77 }
78
tqmx86_gpio_direction_input(struct gpio_chip * chip,unsigned int offset)79 static int tqmx86_gpio_direction_input(struct gpio_chip *chip,
80 unsigned int offset)
81 {
82 /* Direction cannot be changed. Validate is an input. */
83 if (BIT(offset) & TQMX86_DIR_INPUT_MASK)
84 return 0;
85 else
86 return -EINVAL;
87 }
88
tqmx86_gpio_direction_output(struct gpio_chip * chip,unsigned int offset,int value)89 static int tqmx86_gpio_direction_output(struct gpio_chip *chip,
90 unsigned int offset,
91 int value)
92 {
93 /* Direction cannot be changed, validate is an output */
94 if (BIT(offset) & TQMX86_DIR_INPUT_MASK)
95 return -EINVAL;
96
97 tqmx86_gpio_set(chip, offset, value);
98 return 0;
99 }
100
tqmx86_gpio_get_direction(struct gpio_chip * chip,unsigned int offset)101 static int tqmx86_gpio_get_direction(struct gpio_chip *chip,
102 unsigned int offset)
103 {
104 if (TQMX86_DIR_INPUT_MASK & BIT(offset))
105 return GPIO_LINE_DIRECTION_IN;
106
107 return GPIO_LINE_DIRECTION_OUT;
108 }
109
tqmx86_gpio_irq_mask(struct irq_data * data)110 static void tqmx86_gpio_irq_mask(struct irq_data *data)
111 {
112 unsigned int offset = (data->hwirq - TQMX86_NGPO);
113 struct tqmx86_gpio_data *gpio = gpiochip_get_data(
114 irq_data_get_irq_chip_data(data));
115 unsigned long flags;
116 u8 gpiic, mask;
117
118 mask = TQMX86_GPII_MASK << (offset * TQMX86_GPII_BITS);
119
120 raw_spin_lock_irqsave(&gpio->spinlock, flags);
121 gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC);
122 gpiic &= ~mask;
123 tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC);
124 raw_spin_unlock_irqrestore(&gpio->spinlock, flags);
125 }
126
tqmx86_gpio_irq_unmask(struct irq_data * data)127 static void tqmx86_gpio_irq_unmask(struct irq_data *data)
128 {
129 unsigned int offset = (data->hwirq - TQMX86_NGPO);
130 struct tqmx86_gpio_data *gpio = gpiochip_get_data(
131 irq_data_get_irq_chip_data(data));
132 unsigned long flags;
133 u8 gpiic, mask;
134
135 mask = TQMX86_GPII_MASK << (offset * TQMX86_GPII_BITS);
136
137 raw_spin_lock_irqsave(&gpio->spinlock, flags);
138 gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC);
139 gpiic &= ~mask;
140 gpiic |= gpio->irq_type[offset] << (offset * TQMX86_GPII_BITS);
141 tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC);
142 raw_spin_unlock_irqrestore(&gpio->spinlock, flags);
143 }
144
tqmx86_gpio_irq_set_type(struct irq_data * data,unsigned int type)145 static int tqmx86_gpio_irq_set_type(struct irq_data *data, unsigned int type)
146 {
147 struct tqmx86_gpio_data *gpio = gpiochip_get_data(
148 irq_data_get_irq_chip_data(data));
149 unsigned int offset = (data->hwirq - TQMX86_NGPO);
150 unsigned int edge_type = type & IRQF_TRIGGER_MASK;
151 unsigned long flags;
152 u8 new_type, gpiic;
153
154 switch (edge_type) {
155 case IRQ_TYPE_EDGE_RISING:
156 new_type = TQMX86_GPII_RISING;
157 break;
158 case IRQ_TYPE_EDGE_FALLING:
159 new_type = TQMX86_GPII_FALLING;
160 break;
161 case IRQ_TYPE_EDGE_BOTH:
162 new_type = TQMX86_GPII_FALLING | TQMX86_GPII_RISING;
163 break;
164 default:
165 return -EINVAL; /* not supported */
166 }
167
168 gpio->irq_type[offset] = new_type;
169
170 raw_spin_lock_irqsave(&gpio->spinlock, flags);
171 gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC);
172 gpiic &= ~((TQMX86_GPII_MASK) << (offset * TQMX86_GPII_BITS));
173 gpiic |= new_type << (offset * TQMX86_GPII_BITS);
174 tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC);
175 raw_spin_unlock_irqrestore(&gpio->spinlock, flags);
176
177 return 0;
178 }
179
tqmx86_gpio_irq_handler(struct irq_desc * desc)180 static void tqmx86_gpio_irq_handler(struct irq_desc *desc)
181 {
182 struct gpio_chip *chip = irq_desc_get_handler_data(desc);
183 struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip);
184 struct irq_chip *irq_chip = irq_desc_get_chip(desc);
185 unsigned long irq_bits;
186 int i = 0;
187 u8 irq_status;
188
189 chained_irq_enter(irq_chip, desc);
190
191 irq_status = tqmx86_gpio_read(gpio, TQMX86_GPIIS);
192 tqmx86_gpio_write(gpio, irq_status, TQMX86_GPIIS);
193
194 irq_bits = irq_status;
195 for_each_set_bit(i, &irq_bits, TQMX86_NGPI)
196 generic_handle_domain_irq(gpio->chip.irq.domain,
197 i + TQMX86_NGPO);
198
199 chained_irq_exit(irq_chip, desc);
200 }
201
202 /* Minimal runtime PM is needed by the IRQ subsystem */
tqmx86_gpio_runtime_suspend(struct device * dev)203 static int __maybe_unused tqmx86_gpio_runtime_suspend(struct device *dev)
204 {
205 return 0;
206 }
207
tqmx86_gpio_runtime_resume(struct device * dev)208 static int __maybe_unused tqmx86_gpio_runtime_resume(struct device *dev)
209 {
210 return 0;
211 }
212
213 static const struct dev_pm_ops tqmx86_gpio_dev_pm_ops = {
214 SET_RUNTIME_PM_OPS(tqmx86_gpio_runtime_suspend,
215 tqmx86_gpio_runtime_resume, NULL)
216 };
217
tqmx86_init_irq_valid_mask(struct gpio_chip * chip,unsigned long * valid_mask,unsigned int ngpios)218 static void tqmx86_init_irq_valid_mask(struct gpio_chip *chip,
219 unsigned long *valid_mask,
220 unsigned int ngpios)
221 {
222 /* Only GPIOs 4-7 are valid for interrupts. Clear the others */
223 clear_bit(0, valid_mask);
224 clear_bit(1, valid_mask);
225 clear_bit(2, valid_mask);
226 clear_bit(3, valid_mask);
227 }
228
tqmx86_gpio_probe(struct platform_device * pdev)229 static int tqmx86_gpio_probe(struct platform_device *pdev)
230 {
231 struct device *dev = &pdev->dev;
232 struct tqmx86_gpio_data *gpio;
233 struct gpio_chip *chip;
234 struct gpio_irq_chip *girq;
235 void __iomem *io_base;
236 struct resource *res;
237 int ret, irq;
238
239 irq = platform_get_irq_optional(pdev, 0);
240 if (irq < 0 && irq != -ENXIO)
241 return irq;
242
243 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
244 if (!res) {
245 dev_err(&pdev->dev, "Cannot get I/O\n");
246 return -ENODEV;
247 }
248
249 io_base = devm_ioport_map(&pdev->dev, res->start, resource_size(res));
250 if (!io_base)
251 return -ENOMEM;
252
253 gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
254 if (!gpio)
255 return -ENOMEM;
256
257 raw_spin_lock_init(&gpio->spinlock);
258 gpio->io_base = io_base;
259
260 tqmx86_gpio_write(gpio, (u8)~TQMX86_DIR_INPUT_MASK, TQMX86_GPIODD);
261
262 platform_set_drvdata(pdev, gpio);
263
264 chip = &gpio->chip;
265 chip->label = "gpio-tqmx86";
266 chip->owner = THIS_MODULE;
267 chip->can_sleep = false;
268 chip->base = -1;
269 chip->direction_input = tqmx86_gpio_direction_input;
270 chip->direction_output = tqmx86_gpio_direction_output;
271 chip->get_direction = tqmx86_gpio_get_direction;
272 chip->get = tqmx86_gpio_get;
273 chip->set = tqmx86_gpio_set;
274 chip->ngpio = TQMX86_NGPIO;
275 chip->parent = pdev->dev.parent;
276
277 pm_runtime_enable(&pdev->dev);
278
279 if (irq > 0) {
280 struct irq_chip *irq_chip = &gpio->irq_chip;
281 u8 irq_status;
282
283 irq_chip->name = chip->label;
284 irq_chip->irq_mask = tqmx86_gpio_irq_mask;
285 irq_chip->irq_unmask = tqmx86_gpio_irq_unmask;
286 irq_chip->irq_set_type = tqmx86_gpio_irq_set_type;
287
288 /* Mask all interrupts */
289 tqmx86_gpio_write(gpio, 0, TQMX86_GPIIC);
290
291 /* Clear all pending interrupts */
292 irq_status = tqmx86_gpio_read(gpio, TQMX86_GPIIS);
293 tqmx86_gpio_write(gpio, irq_status, TQMX86_GPIIS);
294
295 girq = &chip->irq;
296 girq->chip = irq_chip;
297 girq->parent_handler = tqmx86_gpio_irq_handler;
298 girq->num_parents = 1;
299 girq->parents = devm_kcalloc(&pdev->dev, 1,
300 sizeof(*girq->parents),
301 GFP_KERNEL);
302 if (!girq->parents) {
303 ret = -ENOMEM;
304 goto out_pm_dis;
305 }
306 girq->parents[0] = irq;
307 girq->default_type = IRQ_TYPE_NONE;
308 girq->handler = handle_simple_irq;
309 girq->init_valid_mask = tqmx86_init_irq_valid_mask;
310
311 irq_domain_set_pm_device(girq->domain, dev);
312 }
313
314 ret = devm_gpiochip_add_data(dev, chip, gpio);
315 if (ret) {
316 dev_err(dev, "Could not register GPIO chip\n");
317 goto out_pm_dis;
318 }
319
320 dev_info(dev, "GPIO functionality initialized with %d pins\n",
321 chip->ngpio);
322
323 return 0;
324
325 out_pm_dis:
326 pm_runtime_disable(&pdev->dev);
327
328 return ret;
329 }
330
331 static struct platform_driver tqmx86_gpio_driver = {
332 .driver = {
333 .name = "tqmx86-gpio",
334 .pm = &tqmx86_gpio_dev_pm_ops,
335 },
336 .probe = tqmx86_gpio_probe,
337 };
338
339 module_platform_driver(tqmx86_gpio_driver);
340
341 MODULE_DESCRIPTION("TQMx86 PLD GPIO Driver");
342 MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
343 MODULE_LICENSE("GPL");
344 MODULE_ALIAS("platform:tqmx86-gpio");
345
