xref: /linux/drivers/gpio/gpio-mpfs.c (revision a50eba1e778ad4da5b6f9ddbbf57dabbea59bc05)
1 // SPDX-License-Identifier: (GPL-2.0)
2 /*
3  * Microchip PolarFire SoC (MPFS) GPIO controller driver
4  *
5  * Copyright (c) 2018-2024 Microchip Technology Inc. and its subsidiaries
6  */
7 
8 #include <linux/clk.h>
9 #include <linux/device.h>
10 #include <linux/errno.h>
11 #include <linux/gpio/driver.h>
12 #include <linux/interrupt.h>
13 #include <linux/of_irq.h>
14 #include <linux/platform_device.h>
15 #include <linux/property.h>
16 #include <linux/regmap.h>
17 #include <linux/spinlock.h>
18 
19 #define MPFS_GPIO_CTRL(i)		(0x4 * (i))
20 #define MPFS_MAX_NUM_GPIO		32
21 #define MPFS_GPIO_EN_INT		BIT(3)
22 #define MPFS_GPIO_EN_OUT_BUF		BIT(2)
23 #define MPFS_GPIO_EN_IN			BIT(1)
24 #define MPFS_GPIO_EN_OUT		BIT(0)
25 #define MPFS_GPIO_DIR_MASK		GENMASK(2, 0)
26 
27 #define MPFS_GPIO_TYPE_INT_EDGE_BOTH	0x80
28 #define MPFS_GPIO_TYPE_INT_EDGE_NEG	0x60
29 #define MPFS_GPIO_TYPE_INT_EDGE_POS	0x40
30 #define MPFS_GPIO_TYPE_INT_LEVEL_LOW	0x20
31 #define MPFS_GPIO_TYPE_INT_LEVEL_HIGH	0x00
32 #define MPFS_GPIO_TYPE_INT_MASK		GENMASK(7, 5)
33 #define MPFS_IRQ_REG			0x80
34 
35 #define MPFS_INP_REG			0x84
36 #define COREGPIO_INP_REG		0x90
37 #define MPFS_OUTP_REG			0x88
38 #define COREGPIO_OUTP_REG		0xA0
39 
40 struct mpfs_gpio_reg_offsets {
41 	u8 inp;
42 	u8 outp;
43 };
44 
45 struct mpfs_gpio_chip {
46 	struct regmap *regs;
47 	const struct mpfs_gpio_reg_offsets *offsets;
48 	struct gpio_chip gc;
49 };
50 
51 static const struct regmap_config mpfs_gpio_regmap_config = {
52 	.reg_bits = 32,
53 	.reg_stride = 4,
54 	.val_bits = 32,
55 	.use_raw_spinlock = true,
56 };
57 
58 static int mpfs_gpio_direction_input(struct gpio_chip *gc, unsigned int gpio_index)
59 {
60 	struct mpfs_gpio_chip *mpfs_gpio = gpiochip_get_data(gc);
61 
62 	regmap_update_bits(mpfs_gpio->regs, MPFS_GPIO_CTRL(gpio_index),
63 			   MPFS_GPIO_DIR_MASK, MPFS_GPIO_EN_IN);
64 
65 	return 0;
66 }
67 
68 static int mpfs_gpio_direction_output(struct gpio_chip *gc, unsigned int gpio_index, int value)
69 {
70 	struct mpfs_gpio_chip *mpfs_gpio = gpiochip_get_data(gc);
71 
72 	regmap_update_bits(mpfs_gpio->regs, MPFS_GPIO_CTRL(gpio_index),
73 			   MPFS_GPIO_DIR_MASK, MPFS_GPIO_EN_OUT | MPFS_GPIO_EN_OUT_BUF);
74 	regmap_update_bits(mpfs_gpio->regs, mpfs_gpio->offsets->outp, BIT(gpio_index),
75 			   value << gpio_index);
76 
77 	return 0;
78 }
79 
80 static int mpfs_gpio_get_direction(struct gpio_chip *gc,
81 				   unsigned int gpio_index)
82 {
83 	struct mpfs_gpio_chip *mpfs_gpio = gpiochip_get_data(gc);
84 	unsigned int gpio_cfg;
85 
86 	regmap_read(mpfs_gpio->regs, MPFS_GPIO_CTRL(gpio_index), &gpio_cfg);
87 	if (gpio_cfg & MPFS_GPIO_EN_IN)
88 		return GPIO_LINE_DIRECTION_IN;
89 
90 	return GPIO_LINE_DIRECTION_OUT;
91 }
92 
93 static int mpfs_gpio_get(struct gpio_chip *gc, unsigned int gpio_index)
94 {
95 	struct mpfs_gpio_chip *mpfs_gpio = gpiochip_get_data(gc);
96 
97 	if (mpfs_gpio_get_direction(gc, gpio_index) == GPIO_LINE_DIRECTION_OUT)
98 		return regmap_test_bits(mpfs_gpio->regs, mpfs_gpio->offsets->outp, BIT(gpio_index));
99 	else
100 		return regmap_test_bits(mpfs_gpio->regs, mpfs_gpio->offsets->inp, BIT(gpio_index));
101 }
102 
103 static int mpfs_gpio_set(struct gpio_chip *gc, unsigned int gpio_index, int value)
104 {
105 	struct mpfs_gpio_chip *mpfs_gpio = gpiochip_get_data(gc);
106 	int ret;
107 
108 	mpfs_gpio_get(gc, gpio_index);
109 
110 	ret = regmap_update_bits(mpfs_gpio->regs, mpfs_gpio->offsets->outp,
111 				 BIT(gpio_index), value << gpio_index);
112 
113 	mpfs_gpio_get(gc, gpio_index);
114 
115 	return ret;
116 }
117 
118 static int mpfs_gpio_irq_set_type(struct irq_data *data, unsigned int type)
119 {
120 	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
121 	struct mpfs_gpio_chip *mpfs_gpio = gpiochip_get_data(gc);
122 	int gpio_index = irqd_to_hwirq(data) % 32;
123 	u32 interrupt_type;
124 
125 	switch (type) {
126 	case IRQ_TYPE_EDGE_BOTH:
127 		interrupt_type = MPFS_GPIO_TYPE_INT_EDGE_BOTH;
128 		break;
129 	case IRQ_TYPE_EDGE_FALLING:
130 		interrupt_type = MPFS_GPIO_TYPE_INT_EDGE_NEG;
131 		break;
132 	case IRQ_TYPE_EDGE_RISING:
133 		interrupt_type = MPFS_GPIO_TYPE_INT_EDGE_POS;
134 		break;
135 	case IRQ_TYPE_LEVEL_HIGH:
136 		interrupt_type = MPFS_GPIO_TYPE_INT_LEVEL_HIGH;
137 		break;
138 	case IRQ_TYPE_LEVEL_LOW:
139 		interrupt_type = MPFS_GPIO_TYPE_INT_LEVEL_LOW;
140 		break;
141 	}
142 
143 	regmap_update_bits(mpfs_gpio->regs, MPFS_GPIO_CTRL(gpio_index),
144 			   MPFS_GPIO_TYPE_INT_MASK, interrupt_type);
145 
146 	return 0;
147 }
148 
149 static void mpfs_gpio_irq_unmask(struct irq_data *data)
150 {
151 	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
152 	struct mpfs_gpio_chip *mpfs_gpio = gpiochip_get_data(gc);
153 	int gpio_index = irqd_to_hwirq(data) % 32;
154 
155 	gpiochip_enable_irq(gc, gpio_index);
156 	mpfs_gpio_direction_input(gc, gpio_index);
157 	regmap_update_bits(mpfs_gpio->regs, MPFS_GPIO_CTRL(gpio_index),
158 			     MPFS_GPIO_EN_INT, MPFS_GPIO_EN_INT);
159 }
160 
161 static void mpfs_gpio_irq_mask(struct irq_data *data)
162 {
163 	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
164 	struct mpfs_gpio_chip *mpfs_gpio = gpiochip_get_data(gc);
165 	int gpio_index = irqd_to_hwirq(data) % 32;
166 
167 	regmap_update_bits(mpfs_gpio->regs, MPFS_GPIO_CTRL(gpio_index),
168 			   MPFS_GPIO_EN_INT, 0);
169 	gpiochip_disable_irq(gc, gpio_index);
170 }
171 
172 static const struct irq_chip mpfs_gpio_irqchip = {
173 	.name = "MPFS GPIO",
174 	.irq_set_type = mpfs_gpio_irq_set_type,
175 	.irq_mask = mpfs_gpio_irq_mask,
176 	.irq_unmask = mpfs_gpio_irq_unmask,
177 	.flags = IRQCHIP_IMMUTABLE | IRQCHIP_MASK_ON_SUSPEND,
178 	GPIOCHIP_IRQ_RESOURCE_HELPERS,
179 };
180 
181 static void mpfs_gpio_irq_handler(struct irq_desc *desc)
182 {
183 	struct irq_chip *irqchip = irq_desc_get_chip(desc);
184 	struct mpfs_gpio_chip *mpfs_gpio = irq_desc_get_handler_data(desc);
185 	unsigned long status;
186 	u32 val;
187 	int i;
188 
189 	chained_irq_enter(irqchip, desc);
190 
191 	regmap_read(mpfs_gpio->regs, MPFS_IRQ_REG, &val);
192 	status = val;
193 	for_each_set_bit(i, &status, MPFS_MAX_NUM_GPIO) {
194 		regmap_write(mpfs_gpio->regs, MPFS_IRQ_REG, BIT(i));
195 		generic_handle_domain_irq(mpfs_gpio->gc.irq.domain, i);
196 	}
197 
198 	chained_irq_exit(irqchip, desc);
199 }
200 
201 static int mpfs_gpio_probe(struct platform_device *pdev)
202 {
203 	struct device *dev = &pdev->dev;
204 	struct device_node *node = dev->of_node;
205 	struct mpfs_gpio_chip *mpfs_gpio;
206 	struct gpio_irq_chip *girq;
207 	struct clk *clk;
208 	void __iomem *base;
209 	int ngpios, nirqs, ret;
210 
211 	mpfs_gpio = devm_kzalloc(dev, sizeof(*mpfs_gpio), GFP_KERNEL);
212 	if (!mpfs_gpio)
213 		return -ENOMEM;
214 
215 	mpfs_gpio->offsets = device_get_match_data(&pdev->dev);
216 
217 	base = devm_platform_ioremap_resource(pdev, 0);
218 	if (IS_ERR(base))
219 		return dev_err_probe(dev, PTR_ERR(base), "failed to ioremap memory resource\n");
220 
221 	mpfs_gpio->regs = devm_regmap_init_mmio(dev, base, &mpfs_gpio_regmap_config);
222 	if (IS_ERR(mpfs_gpio->regs))
223 		return dev_err_probe(dev, PTR_ERR(mpfs_gpio->regs),
224 				     "failed to initialise regmap\n");
225 
226 	clk = devm_clk_get_enabled(dev, NULL);
227 	if (IS_ERR(clk))
228 		return dev_err_probe(dev, PTR_ERR(clk), "failed to get and enable clock\n");
229 
230 	ngpios = MPFS_MAX_NUM_GPIO;
231 	device_property_read_u32(dev, "ngpios", &ngpios);
232 	if (ngpios > MPFS_MAX_NUM_GPIO)
233 		ngpios = MPFS_MAX_NUM_GPIO;
234 
235 	mpfs_gpio->gc.direction_input = mpfs_gpio_direction_input;
236 	mpfs_gpio->gc.direction_output = mpfs_gpio_direction_output;
237 	mpfs_gpio->gc.get_direction = mpfs_gpio_get_direction;
238 	mpfs_gpio->gc.get = mpfs_gpio_get;
239 	mpfs_gpio->gc.set = mpfs_gpio_set;
240 	mpfs_gpio->gc.base = -1;
241 	mpfs_gpio->gc.ngpio = ngpios;
242 	mpfs_gpio->gc.label = dev_name(dev);
243 	mpfs_gpio->gc.parent = dev;
244 	mpfs_gpio->gc.owner = THIS_MODULE;
245 
246 	nirqs = of_irq_count(node);
247 	if (nirqs > MPFS_MAX_NUM_GPIO)
248 		return -ENXIO;
249 
250 	if (nirqs) {
251 		girq = &mpfs_gpio->gc.irq;
252 
253 		gpio_irq_chip_set_chip(girq, &mpfs_gpio_irqchip);
254 
255 		girq->num_parents = nirqs;
256 		girq->parents = devm_kcalloc(&pdev->dev, girq->num_parents,
257 					     sizeof(*girq->parents), GFP_KERNEL);
258 		if (!girq->parents)
259 			return -ENOMEM;
260 
261 		for (int i = 0; i < nirqs; i++) {
262 			ret = platform_get_irq(pdev, i);
263 			if (ret < 0)
264 				return ret;
265 
266 			girq->parents[i] = ret;
267 			girq->parent_handler_data = mpfs_gpio;
268 			girq->parent_handler = mpfs_gpio_irq_handler;
269 		}
270 
271 		girq->handler = handle_level_irq;
272 		girq->default_type = IRQ_TYPE_NONE;
273 	}
274 
275 	return devm_gpiochip_add_data(dev, &mpfs_gpio->gc, mpfs_gpio);
276 }
277 
278 static const struct mpfs_gpio_reg_offsets mpfs_reg_offsets = {
279 	.inp = MPFS_INP_REG,
280 	.outp = MPFS_OUTP_REG,
281 };
282 
283 static const struct mpfs_gpio_reg_offsets coregpio_reg_offsets = {
284 	.inp = COREGPIO_INP_REG,
285 	.outp = COREGPIO_OUTP_REG,
286 };
287 
288 static const struct of_device_id mpfs_gpio_of_ids[] = {
289 	{
290 		.compatible = "microchip,mpfs-gpio",
291 		.data = &mpfs_reg_offsets,
292 	}, {
293 		.compatible = "microchip,coregpio-rtl-v3",
294 		.data = &coregpio_reg_offsets,
295 	},
296 	{ /* end of list */ }
297 };
298 
299 static struct platform_driver mpfs_gpio_driver = {
300 	.probe = mpfs_gpio_probe,
301 	.driver = {
302 		.name = "microchip,mpfs-gpio",
303 		.of_match_table = mpfs_gpio_of_ids,
304 	},
305 };
306 builtin_platform_driver(mpfs_gpio_driver);
307