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b868db94 AL |
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> | |
8e43827b | 18 | #include <linux/seq_file.h> |
b868db94 AL |
19 | #include <linux/slab.h> |
20 | ||
21 | #define TQMX86_NGPIO 8 | |
22 | #define TQMX86_NGPO 4 /* 0-3 - output */ | |
23 | #define TQMX86_NGPI 4 /* 4-7 - input */ | |
24 | #define TQMX86_DIR_INPUT_MASK 0xf0 /* 0-3 - output, 4-7 - input */ | |
25 | ||
26 | #define TQMX86_GPIODD 0 /* GPIO Data Direction Register */ | |
27 | #define TQMX86_GPIOD 1 /* GPIO Data Register */ | |
28 | #define TQMX86_GPIIC 3 /* GPI Interrupt Configuration Register */ | |
29 | #define TQMX86_GPIIS 4 /* GPI Interrupt Status Register */ | |
30 | ||
31 | #define TQMX86_GPII_FALLING BIT(0) | |
32 | #define TQMX86_GPII_RISING BIT(1) | |
33 | #define TQMX86_GPII_MASK (BIT(0) | BIT(1)) | |
34 | #define TQMX86_GPII_BITS 2 | |
35 | ||
36 | struct tqmx86_gpio_data { | |
37 | struct gpio_chip chip; | |
b868db94 AL |
38 | void __iomem *io_base; |
39 | int irq; | |
40 | raw_spinlock_t spinlock; | |
41 | u8 irq_type[TQMX86_NGPI]; | |
42 | }; | |
43 | ||
44 | static u8 tqmx86_gpio_read(struct tqmx86_gpio_data *gd, unsigned int reg) | |
45 | { | |
46 | return ioread8(gd->io_base + reg); | |
47 | } | |
48 | ||
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 | ||
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 | ||
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 | ||
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 | ||
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; | |
18fadd6a AL |
96 | |
97 | tqmx86_gpio_set(chip, offset, value); | |
98 | return 0; | |
b868db94 AL |
99 | } |
100 | ||
101 | static int tqmx86_gpio_get_direction(struct gpio_chip *chip, | |
102 | unsigned int offset) | |
103 | { | |
e42615ec MV |
104 | if (TQMX86_DIR_INPUT_MASK & BIT(offset)) |
105 | return GPIO_LINE_DIRECTION_IN; | |
106 | ||
107 | return GPIO_LINE_DIRECTION_OUT; | |
b868db94 AL |
108 | } |
109 | ||
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); | |
8e43827b | 125 | gpiochip_disable_irq(&gpio->chip, irqd_to_hwirq(data)); |
b868db94 AL |
126 | } |
127 | ||
128 | static void tqmx86_gpio_irq_unmask(struct irq_data *data) | |
129 | { | |
130 | unsigned int offset = (data->hwirq - TQMX86_NGPO); | |
131 | struct tqmx86_gpio_data *gpio = gpiochip_get_data( | |
132 | irq_data_get_irq_chip_data(data)); | |
133 | unsigned long flags; | |
134 | u8 gpiic, mask; | |
135 | ||
136 | mask = TQMX86_GPII_MASK << (offset * TQMX86_GPII_BITS); | |
137 | ||
8e43827b | 138 | gpiochip_enable_irq(&gpio->chip, irqd_to_hwirq(data)); |
b868db94 AL |
139 | raw_spin_lock_irqsave(&gpio->spinlock, flags); |
140 | gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC); | |
141 | gpiic &= ~mask; | |
142 | gpiic |= gpio->irq_type[offset] << (offset * TQMX86_GPII_BITS); | |
143 | tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC); | |
144 | raw_spin_unlock_irqrestore(&gpio->spinlock, flags); | |
145 | } | |
146 | ||
147 | static int tqmx86_gpio_irq_set_type(struct irq_data *data, unsigned int type) | |
148 | { | |
149 | struct tqmx86_gpio_data *gpio = gpiochip_get_data( | |
150 | irq_data_get_irq_chip_data(data)); | |
151 | unsigned int offset = (data->hwirq - TQMX86_NGPO); | |
152 | unsigned int edge_type = type & IRQF_TRIGGER_MASK; | |
153 | unsigned long flags; | |
154 | u8 new_type, gpiic; | |
155 | ||
156 | switch (edge_type) { | |
157 | case IRQ_TYPE_EDGE_RISING: | |
158 | new_type = TQMX86_GPII_RISING; | |
159 | break; | |
160 | case IRQ_TYPE_EDGE_FALLING: | |
161 | new_type = TQMX86_GPII_FALLING; | |
162 | break; | |
163 | case IRQ_TYPE_EDGE_BOTH: | |
164 | new_type = TQMX86_GPII_FALLING | TQMX86_GPII_RISING; | |
165 | break; | |
166 | default: | |
167 | return -EINVAL; /* not supported */ | |
168 | } | |
169 | ||
170 | gpio->irq_type[offset] = new_type; | |
171 | ||
172 | raw_spin_lock_irqsave(&gpio->spinlock, flags); | |
173 | gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC); | |
174 | gpiic &= ~((TQMX86_GPII_MASK) << (offset * TQMX86_GPII_BITS)); | |
175 | gpiic |= new_type << (offset * TQMX86_GPII_BITS); | |
176 | tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC); | |
177 | raw_spin_unlock_irqrestore(&gpio->spinlock, flags); | |
178 | ||
179 | return 0; | |
180 | } | |
181 | ||
182 | static void tqmx86_gpio_irq_handler(struct irq_desc *desc) | |
183 | { | |
184 | struct gpio_chip *chip = irq_desc_get_handler_data(desc); | |
185 | struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip); | |
186 | struct irq_chip *irq_chip = irq_desc_get_chip(desc); | |
187 | unsigned long irq_bits; | |
dbd1c54f | 188 | int i = 0; |
b868db94 AL |
189 | u8 irq_status; |
190 | ||
191 | chained_irq_enter(irq_chip, desc); | |
192 | ||
193 | irq_status = tqmx86_gpio_read(gpio, TQMX86_GPIIS); | |
194 | tqmx86_gpio_write(gpio, irq_status, TQMX86_GPIIS); | |
195 | ||
196 | irq_bits = irq_status; | |
dbd1c54f MZ |
197 | for_each_set_bit(i, &irq_bits, TQMX86_NGPI) |
198 | generic_handle_domain_irq(gpio->chip.irq.domain, | |
199 | i + TQMX86_NGPO); | |
b868db94 AL |
200 | |
201 | chained_irq_exit(irq_chip, desc); | |
202 | } | |
203 | ||
204 | /* Minimal runtime PM is needed by the IRQ subsystem */ | |
205 | static int __maybe_unused tqmx86_gpio_runtime_suspend(struct device *dev) | |
206 | { | |
207 | return 0; | |
208 | } | |
209 | ||
210 | static int __maybe_unused tqmx86_gpio_runtime_resume(struct device *dev) | |
211 | { | |
212 | return 0; | |
213 | } | |
214 | ||
215 | static const struct dev_pm_ops tqmx86_gpio_dev_pm_ops = { | |
216 | SET_RUNTIME_PM_OPS(tqmx86_gpio_runtime_suspend, | |
217 | tqmx86_gpio_runtime_resume, NULL) | |
218 | }; | |
219 | ||
5fbe5b58 LW |
220 | static void tqmx86_init_irq_valid_mask(struct gpio_chip *chip, |
221 | unsigned long *valid_mask, | |
222 | unsigned int ngpios) | |
223 | { | |
224 | /* Only GPIOs 4-7 are valid for interrupts. Clear the others */ | |
225 | clear_bit(0, valid_mask); | |
226 | clear_bit(1, valid_mask); | |
227 | clear_bit(2, valid_mask); | |
228 | clear_bit(3, valid_mask); | |
229 | } | |
230 | ||
8e43827b LW |
231 | static void tqmx86_gpio_irq_print_chip(struct irq_data *d, struct seq_file *p) |
232 | { | |
233 | struct gpio_chip *gc = irq_data_get_irq_chip_data(d); | |
234 | ||
235 | seq_printf(p, gc->label); | |
236 | } | |
237 | ||
238 | static const struct irq_chip tqmx86_gpio_irq_chip = { | |
239 | .irq_mask = tqmx86_gpio_irq_mask, | |
240 | .irq_unmask = tqmx86_gpio_irq_unmask, | |
241 | .irq_set_type = tqmx86_gpio_irq_set_type, | |
242 | .irq_print_chip = tqmx86_gpio_irq_print_chip, | |
243 | .flags = IRQCHIP_IMMUTABLE, | |
244 | GPIOCHIP_IRQ_RESOURCE_HELPERS, | |
245 | }; | |
246 | ||
b868db94 AL |
247 | static int tqmx86_gpio_probe(struct platform_device *pdev) |
248 | { | |
249 | struct device *dev = &pdev->dev; | |
250 | struct tqmx86_gpio_data *gpio; | |
251 | struct gpio_chip *chip; | |
74639d66 | 252 | struct gpio_irq_chip *girq; |
b868db94 AL |
253 | void __iomem *io_base; |
254 | struct resource *res; | |
255 | int ret, irq; | |
256 | ||
9b87f435 MS |
257 | irq = platform_get_irq_optional(pdev, 0); |
258 | if (irq < 0 && irq != -ENXIO) | |
b868db94 AL |
259 | return irq; |
260 | ||
261 | res = platform_get_resource(pdev, IORESOURCE_IO, 0); | |
262 | if (!res) { | |
263 | dev_err(&pdev->dev, "Cannot get I/O\n"); | |
264 | return -ENODEV; | |
265 | } | |
266 | ||
267 | io_base = devm_ioport_map(&pdev->dev, res->start, resource_size(res)); | |
268 | if (!io_base) | |
269 | return -ENOMEM; | |
270 | ||
271 | gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL); | |
272 | if (!gpio) | |
273 | return -ENOMEM; | |
274 | ||
275 | raw_spin_lock_init(&gpio->spinlock); | |
276 | gpio->io_base = io_base; | |
277 | ||
278 | tqmx86_gpio_write(gpio, (u8)~TQMX86_DIR_INPUT_MASK, TQMX86_GPIODD); | |
279 | ||
b868db94 AL |
280 | chip = &gpio->chip; |
281 | chip->label = "gpio-tqmx86"; | |
282 | chip->owner = THIS_MODULE; | |
283 | chip->can_sleep = false; | |
284 | chip->base = -1; | |
285 | chip->direction_input = tqmx86_gpio_direction_input; | |
286 | chip->direction_output = tqmx86_gpio_direction_output; | |
287 | chip->get_direction = tqmx86_gpio_get_direction; | |
288 | chip->get = tqmx86_gpio_get; | |
289 | chip->set = tqmx86_gpio_set; | |
290 | chip->ngpio = TQMX86_NGPIO; | |
b868db94 AL |
291 | chip->parent = pdev->dev.parent; |
292 | ||
293 | pm_runtime_enable(&pdev->dev); | |
294 | ||
9b87f435 | 295 | if (irq > 0) { |
b868db94 AL |
296 | u8 irq_status; |
297 | ||
b868db94 AL |
298 | /* Mask all interrupts */ |
299 | tqmx86_gpio_write(gpio, 0, TQMX86_GPIIC); | |
300 | ||
301 | /* Clear all pending interrupts */ | |
302 | irq_status = tqmx86_gpio_read(gpio, TQMX86_GPIIS); | |
303 | tqmx86_gpio_write(gpio, irq_status, TQMX86_GPIIS); | |
304 | ||
74639d66 | 305 | girq = &chip->irq; |
8e43827b | 306 | gpio_irq_chip_set_chip(girq, &tqmx86_gpio_irq_chip); |
74639d66 LW |
307 | girq->parent_handler = tqmx86_gpio_irq_handler; |
308 | girq->num_parents = 1; | |
309 | girq->parents = devm_kcalloc(&pdev->dev, 1, | |
310 | sizeof(*girq->parents), | |
311 | GFP_KERNEL); | |
312 | if (!girq->parents) { | |
313 | ret = -ENOMEM; | |
96be65d1 | 314 | goto out_pm_dis; |
b868db94 | 315 | } |
74639d66 LW |
316 | girq->parents[0] = irq; |
317 | girq->default_type = IRQ_TYPE_NONE; | |
318 | girq->handler = handle_simple_irq; | |
5fbe5b58 | 319 | girq->init_valid_mask = tqmx86_init_irq_valid_mask; |
21a9acc1 DM |
320 | |
321 | irq_domain_set_pm_device(girq->domain, dev); | |
74639d66 | 322 | } |
b868db94 | 323 | |
74639d66 LW |
324 | ret = devm_gpiochip_add_data(dev, chip, gpio); |
325 | if (ret) { | |
326 | dev_err(dev, "Could not register GPIO chip\n"); | |
327 | goto out_pm_dis; | |
b868db94 AL |
328 | } |
329 | ||
b868db94 AL |
330 | dev_info(dev, "GPIO functionality initialized with %d pins\n", |
331 | chip->ngpio); | |
332 | ||
333 | return 0; | |
334 | ||
b868db94 AL |
335 | out_pm_dis: |
336 | pm_runtime_disable(&pdev->dev); | |
337 | ||
338 | return ret; | |
339 | } | |
340 | ||
341 | static struct platform_driver tqmx86_gpio_driver = { | |
342 | .driver = { | |
343 | .name = "tqmx86-gpio", | |
344 | .pm = &tqmx86_gpio_dev_pm_ops, | |
345 | }, | |
346 | .probe = tqmx86_gpio_probe, | |
347 | }; | |
348 | ||
349 | module_platform_driver(tqmx86_gpio_driver); | |
350 | ||
351 | MODULE_DESCRIPTION("TQMx86 PLD GPIO Driver"); | |
352 | MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>"); | |
353 | MODULE_LICENSE("GPL"); | |
354 | MODULE_ALIAS("platform:tqmx86-gpio"); |