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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 | ||
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 | { | |
104 | return !!(TQMX86_DIR_INPUT_MASK & BIT(offset)); | |
105 | } | |
106 | ||
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 | ||
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 | ||
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 | ||
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 */ | |
202 | static int __maybe_unused tqmx86_gpio_runtime_suspend(struct device *dev) | |
203 | { | |
204 | return 0; | |
205 | } | |
206 | ||
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 | ||
217 | static int tqmx86_gpio_probe(struct platform_device *pdev) | |
218 | { | |
219 | struct device *dev = &pdev->dev; | |
220 | struct tqmx86_gpio_data *gpio; | |
221 | struct gpio_chip *chip; | |
222 | void __iomem *io_base; | |
223 | struct resource *res; | |
224 | int ret, irq; | |
225 | ||
226 | irq = platform_get_irq(pdev, 0); | |
227 | if (irq < 0) | |
228 | return irq; | |
229 | ||
230 | res = platform_get_resource(pdev, IORESOURCE_IO, 0); | |
231 | if (!res) { | |
232 | dev_err(&pdev->dev, "Cannot get I/O\n"); | |
233 | return -ENODEV; | |
234 | } | |
235 | ||
236 | io_base = devm_ioport_map(&pdev->dev, res->start, resource_size(res)); | |
237 | if (!io_base) | |
238 | return -ENOMEM; | |
239 | ||
240 | gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL); | |
241 | if (!gpio) | |
242 | return -ENOMEM; | |
243 | ||
244 | raw_spin_lock_init(&gpio->spinlock); | |
245 | gpio->io_base = io_base; | |
246 | ||
247 | tqmx86_gpio_write(gpio, (u8)~TQMX86_DIR_INPUT_MASK, TQMX86_GPIODD); | |
248 | ||
249 | platform_set_drvdata(pdev, gpio); | |
250 | ||
251 | chip = &gpio->chip; | |
252 | chip->label = "gpio-tqmx86"; | |
253 | chip->owner = THIS_MODULE; | |
254 | chip->can_sleep = false; | |
255 | chip->base = -1; | |
256 | chip->direction_input = tqmx86_gpio_direction_input; | |
257 | chip->direction_output = tqmx86_gpio_direction_output; | |
258 | chip->get_direction = tqmx86_gpio_get_direction; | |
259 | chip->get = tqmx86_gpio_get; | |
260 | chip->set = tqmx86_gpio_set; | |
261 | chip->ngpio = TQMX86_NGPIO; | |
262 | chip->irq.need_valid_mask = true; | |
263 | chip->parent = pdev->dev.parent; | |
264 | ||
265 | pm_runtime_enable(&pdev->dev); | |
266 | ||
267 | ret = devm_gpiochip_add_data(dev, chip, gpio); | |
268 | if (ret) { | |
269 | dev_err(dev, "Could not register GPIO chip\n"); | |
270 | goto out_pm_dis; | |
271 | } | |
272 | ||
273 | if (irq) { | |
274 | struct irq_chip *irq_chip = &gpio->irq_chip; | |
275 | u8 irq_status; | |
276 | ||
277 | irq_chip->name = chip->label; | |
278 | irq_chip->parent_device = &pdev->dev; | |
279 | irq_chip->irq_mask = tqmx86_gpio_irq_mask; | |
280 | irq_chip->irq_unmask = tqmx86_gpio_irq_unmask; | |
281 | irq_chip->irq_set_type = tqmx86_gpio_irq_set_type; | |
282 | ||
283 | /* Mask all interrupts */ | |
284 | tqmx86_gpio_write(gpio, 0, TQMX86_GPIIC); | |
285 | ||
286 | /* Clear all pending interrupts */ | |
287 | irq_status = tqmx86_gpio_read(gpio, TQMX86_GPIIS); | |
288 | tqmx86_gpio_write(gpio, irq_status, TQMX86_GPIIS); | |
289 | ||
290 | ret = gpiochip_irqchip_add(chip, irq_chip, | |
291 | 0, handle_simple_irq, | |
292 | IRQ_TYPE_EDGE_BOTH); | |
293 | if (ret) { | |
294 | dev_err(dev, "Could not add irq chip\n"); | |
96be65d1 | 295 | goto out_pm_dis; |
b868db94 AL |
296 | } |
297 | ||
298 | gpiochip_set_chained_irqchip(chip, irq_chip, | |
299 | irq, tqmx86_gpio_irq_handler); | |
300 | } | |
301 | ||
302 | /* Only GPIOs 4-7 are valid for interrupts. Clear the others */ | |
303 | clear_bit(0, chip->irq.valid_mask); | |
304 | clear_bit(1, chip->irq.valid_mask); | |
305 | clear_bit(2, chip->irq.valid_mask); | |
306 | clear_bit(3, chip->irq.valid_mask); | |
307 | ||
308 | dev_info(dev, "GPIO functionality initialized with %d pins\n", | |
309 | chip->ngpio); | |
310 | ||
311 | return 0; | |
312 | ||
b868db94 AL |
313 | out_pm_dis: |
314 | pm_runtime_disable(&pdev->dev); | |
315 | ||
316 | return ret; | |
317 | } | |
318 | ||
319 | static struct platform_driver tqmx86_gpio_driver = { | |
320 | .driver = { | |
321 | .name = "tqmx86-gpio", | |
322 | .pm = &tqmx86_gpio_dev_pm_ops, | |
323 | }, | |
324 | .probe = tqmx86_gpio_probe, | |
325 | }; | |
326 | ||
327 | module_platform_driver(tqmx86_gpio_driver); | |
328 | ||
329 | MODULE_DESCRIPTION("TQMx86 PLD GPIO Driver"); | |
330 | MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>"); | |
331 | MODULE_LICENSE("GPL"); | |
332 | MODULE_ALIAS("platform:tqmx86-gpio"); |