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 return !!(TQMX86_DIR_INPUT_MASK & BIT(offset));
105 }
106
tqmx86_gpio_irq_mask(struct irq_data * data)107 static void tqmx86_gpio_irq_mask(struct irq_data *data)
108 {
109 unsigned int offset = (data->hwirq - TQMX86_NGPO);
110 struct tqmx86_gpio_data *gpio = gpiochip_get_data(
111 irq_data_get_irq_chip_data(data));
112 unsigned long flags;
113 u8 gpiic, mask;
114
115 mask = TQMX86_GPII_MASK << (offset * TQMX86_GPII_BITS);
116
117 raw_spin_lock_irqsave(&gpio->spinlock, flags);
118 gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC);
119 gpiic &= ~mask;
120 tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC);
121 raw_spin_unlock_irqrestore(&gpio->spinlock, flags);
122 }
123
tqmx86_gpio_irq_unmask(struct irq_data * data)124 static void tqmx86_gpio_irq_unmask(struct irq_data *data)
125 {
126 unsigned int offset = (data->hwirq - TQMX86_NGPO);
127 struct tqmx86_gpio_data *gpio = gpiochip_get_data(
128 irq_data_get_irq_chip_data(data));
129 unsigned long flags;
130 u8 gpiic, mask;
131
132 mask = TQMX86_GPII_MASK << (offset * TQMX86_GPII_BITS);
133
134 raw_spin_lock_irqsave(&gpio->spinlock, flags);
135 gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC);
136 gpiic &= ~mask;
137 gpiic |= gpio->irq_type[offset] << (offset * TQMX86_GPII_BITS);
138 tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC);
139 raw_spin_unlock_irqrestore(&gpio->spinlock, flags);
140 }
141
tqmx86_gpio_irq_set_type(struct irq_data * data,unsigned int type)142 static int tqmx86_gpio_irq_set_type(struct irq_data *data, unsigned int type)
143 {
144 struct tqmx86_gpio_data *gpio = gpiochip_get_data(
145 irq_data_get_irq_chip_data(data));
146 unsigned int offset = (data->hwirq - TQMX86_NGPO);
147 unsigned int edge_type = type & IRQF_TRIGGER_MASK;
148 unsigned long flags;
149 u8 new_type, gpiic;
150
151 switch (edge_type) {
152 case IRQ_TYPE_EDGE_RISING:
153 new_type = TQMX86_GPII_RISING;
154 break;
155 case IRQ_TYPE_EDGE_FALLING:
156 new_type = TQMX86_GPII_FALLING;
157 break;
158 case IRQ_TYPE_EDGE_BOTH:
159 new_type = TQMX86_GPII_FALLING | TQMX86_GPII_RISING;
160 break;
161 default:
162 return -EINVAL; /* not supported */
163 }
164
165 gpio->irq_type[offset] = new_type;
166
167 raw_spin_lock_irqsave(&gpio->spinlock, flags);
168 gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC);
169 gpiic &= ~((TQMX86_GPII_MASK) << (offset * TQMX86_GPII_BITS));
170 gpiic |= new_type << (offset * TQMX86_GPII_BITS);
171 tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC);
172 raw_spin_unlock_irqrestore(&gpio->spinlock, flags);
173
174 return 0;
175 }
176
tqmx86_gpio_irq_handler(struct irq_desc * desc)177 static void tqmx86_gpio_irq_handler(struct irq_desc *desc)
178 {
179 struct gpio_chip *chip = irq_desc_get_handler_data(desc);
180 struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip);
181 struct irq_chip *irq_chip = irq_desc_get_chip(desc);
182 unsigned long irq_bits;
183 int i = 0, child_irq;
184 u8 irq_status;
185
186 chained_irq_enter(irq_chip, desc);
187
188 irq_status = tqmx86_gpio_read(gpio, TQMX86_GPIIS);
189 tqmx86_gpio_write(gpio, irq_status, TQMX86_GPIIS);
190
191 irq_bits = irq_status;
192 for_each_set_bit(i, &irq_bits, TQMX86_NGPI) {
193 child_irq = irq_find_mapping(gpio->chip.irq.domain,
194 i + TQMX86_NGPO);
195 generic_handle_irq(child_irq);
196 }
197
198 chained_irq_exit(irq_chip, desc);
199 }
200
201 /* Minimal runtime PM is needed by the IRQ subsystem */
tqmx86_gpio_runtime_suspend(struct device * dev)202 static int __maybe_unused tqmx86_gpio_runtime_suspend(struct device *dev)
203 {
204 return 0;
205 }
206
tqmx86_gpio_runtime_resume(struct device * dev)207 static int __maybe_unused tqmx86_gpio_runtime_resume(struct device *dev)
208 {
209 return 0;
210 }
211
212 static const struct dev_pm_ops tqmx86_gpio_dev_pm_ops = {
213 SET_RUNTIME_PM_OPS(tqmx86_gpio_runtime_suspend,
214 tqmx86_gpio_runtime_resume, NULL)
215 };
216
tqmx86_init_irq_valid_mask(struct gpio_chip * chip,unsigned long * valid_mask,unsigned int ngpios)217 static void tqmx86_init_irq_valid_mask(struct gpio_chip *chip,
218 unsigned long *valid_mask,
219 unsigned int ngpios)
220 {
221 /* Only GPIOs 4-7 are valid for interrupts. Clear the others */
222 clear_bit(0, valid_mask);
223 clear_bit(1, valid_mask);
224 clear_bit(2, valid_mask);
225 clear_bit(3, valid_mask);
226 }
227
tqmx86_gpio_probe(struct platform_device * pdev)228 static int tqmx86_gpio_probe(struct platform_device *pdev)
229 {
230 struct device *dev = &pdev->dev;
231 struct tqmx86_gpio_data *gpio;
232 struct gpio_chip *chip;
233 struct gpio_irq_chip *girq;
234 void __iomem *io_base;
235 struct resource *res;
236 int ret, irq;
237
238 irq = platform_get_irq(pdev, 0);
239 if (irq < 0)
240 return irq;
241
242 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
243 if (!res) {
244 dev_err(&pdev->dev, "Cannot get I/O\n");
245 return -ENODEV;
246 }
247
248 io_base = devm_ioport_map(&pdev->dev, res->start, resource_size(res));
249 if (!io_base)
250 return -ENOMEM;
251
252 gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
253 if (!gpio)
254 return -ENOMEM;
255
256 raw_spin_lock_init(&gpio->spinlock);
257 gpio->io_base = io_base;
258
259 tqmx86_gpio_write(gpio, (u8)~TQMX86_DIR_INPUT_MASK, TQMX86_GPIODD);
260
261 platform_set_drvdata(pdev, gpio);
262
263 chip = &gpio->chip;
264 chip->label = "gpio-tqmx86";
265 chip->owner = THIS_MODULE;
266 chip->can_sleep = false;
267 chip->base = -1;
268 chip->direction_input = tqmx86_gpio_direction_input;
269 chip->direction_output = tqmx86_gpio_direction_output;
270 chip->get_direction = tqmx86_gpio_get_direction;
271 chip->get = tqmx86_gpio_get;
272 chip->set = tqmx86_gpio_set;
273 chip->ngpio = TQMX86_NGPIO;
274 chip->parent = pdev->dev.parent;
275
276 pm_runtime_enable(&pdev->dev);
277
278 if (irq) {
279 struct irq_chip *irq_chip = &gpio->irq_chip;
280 u8 irq_status;
281
282 irq_chip->name = chip->label;
283 irq_chip->parent_device = &pdev->dev;
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
312 ret = devm_gpiochip_add_data(dev, chip, gpio);
313 if (ret) {
314 dev_err(dev, "Could not register GPIO chip\n");
315 goto out_pm_dis;
316 }
317
318 dev_info(dev, "GPIO functionality initialized with %d pins\n",
319 chip->ngpio);
320
321 return 0;
322
323 out_pm_dis:
324 pm_runtime_disable(&pdev->dev);
325
326 return ret;
327 }
328
329 static struct platform_driver tqmx86_gpio_driver = {
330 .driver = {
331 .name = "tqmx86-gpio",
332 .pm = &tqmx86_gpio_dev_pm_ops,
333 },
334 .probe = tqmx86_gpio_probe,
335 };
336
337 module_platform_driver(tqmx86_gpio_driver);
338
339 MODULE_DESCRIPTION("TQMx86 PLD GPIO Driver");
340 MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
341 MODULE_LICENSE("GPL");
342 MODULE_ALIAS("platform:tqmx86-gpio");
343