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72ab2f76 JK |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | ||
3 | /* | |
4 | * Copyright 2017-2018 Cadence | |
5 | * | |
6 | * Authors: | |
7 | * Jan Kotas <[email protected]> | |
8 | * Boris Brezillon <[email protected]> | |
9 | */ | |
10 | ||
11 | #include <linux/gpio/driver.h> | |
12 | #include <linux/clk.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/spinlock.h> | |
18 | ||
19 | #define CDNS_GPIO_BYPASS_MODE 0x00 | |
20 | #define CDNS_GPIO_DIRECTION_MODE 0x04 | |
21 | #define CDNS_GPIO_OUTPUT_EN 0x08 | |
22 | #define CDNS_GPIO_OUTPUT_VALUE 0x0c | |
23 | #define CDNS_GPIO_INPUT_VALUE 0x10 | |
24 | #define CDNS_GPIO_IRQ_MASK 0x14 | |
25 | #define CDNS_GPIO_IRQ_EN 0x18 | |
26 | #define CDNS_GPIO_IRQ_DIS 0x1c | |
27 | #define CDNS_GPIO_IRQ_STATUS 0x20 | |
28 | #define CDNS_GPIO_IRQ_TYPE 0x24 | |
29 | #define CDNS_GPIO_IRQ_VALUE 0x28 | |
30 | #define CDNS_GPIO_IRQ_ANY_EDGE 0x2c | |
31 | ||
32 | struct cdns_gpio_chip { | |
33 | struct gpio_chip gc; | |
34 | struct clk *pclk; | |
35 | void __iomem *regs; | |
36 | u32 bypass_orig; | |
37 | }; | |
38 | ||
39 | static int cdns_gpio_request(struct gpio_chip *chip, unsigned int offset) | |
40 | { | |
41 | struct cdns_gpio_chip *cgpio = gpiochip_get_data(chip); | |
42 | unsigned long flags; | |
43 | ||
3c938cc5 | 44 | raw_spin_lock_irqsave(&chip->bgpio_lock, flags); |
72ab2f76 JK |
45 | |
46 | iowrite32(ioread32(cgpio->regs + CDNS_GPIO_BYPASS_MODE) & ~BIT(offset), | |
47 | cgpio->regs + CDNS_GPIO_BYPASS_MODE); | |
48 | ||
3c938cc5 | 49 | raw_spin_unlock_irqrestore(&chip->bgpio_lock, flags); |
72ab2f76 JK |
50 | return 0; |
51 | } | |
52 | ||
53 | static void cdns_gpio_free(struct gpio_chip *chip, unsigned int offset) | |
54 | { | |
55 | struct cdns_gpio_chip *cgpio = gpiochip_get_data(chip); | |
56 | unsigned long flags; | |
57 | ||
3c938cc5 | 58 | raw_spin_lock_irqsave(&chip->bgpio_lock, flags); |
72ab2f76 JK |
59 | |
60 | iowrite32(ioread32(cgpio->regs + CDNS_GPIO_BYPASS_MODE) | | |
61 | (BIT(offset) & cgpio->bypass_orig), | |
62 | cgpio->regs + CDNS_GPIO_BYPASS_MODE); | |
63 | ||
3c938cc5 | 64 | raw_spin_unlock_irqrestore(&chip->bgpio_lock, flags); |
72ab2f76 JK |
65 | } |
66 | ||
67 | static void cdns_gpio_irq_mask(struct irq_data *d) | |
68 | { | |
69 | struct gpio_chip *chip = irq_data_get_irq_chip_data(d); | |
70 | struct cdns_gpio_chip *cgpio = gpiochip_get_data(chip); | |
71 | ||
72 | iowrite32(BIT(d->hwirq), cgpio->regs + CDNS_GPIO_IRQ_DIS); | |
150a9880 | 73 | gpiochip_disable_irq(chip, irqd_to_hwirq(d)); |
72ab2f76 JK |
74 | } |
75 | ||
76 | static void cdns_gpio_irq_unmask(struct irq_data *d) | |
77 | { | |
78 | struct gpio_chip *chip = irq_data_get_irq_chip_data(d); | |
79 | struct cdns_gpio_chip *cgpio = gpiochip_get_data(chip); | |
80 | ||
150a9880 | 81 | gpiochip_enable_irq(chip, irqd_to_hwirq(d)); |
72ab2f76 JK |
82 | iowrite32(BIT(d->hwirq), cgpio->regs + CDNS_GPIO_IRQ_EN); |
83 | } | |
84 | ||
85 | static int cdns_gpio_irq_set_type(struct irq_data *d, unsigned int type) | |
86 | { | |
87 | struct gpio_chip *chip = irq_data_get_irq_chip_data(d); | |
88 | struct cdns_gpio_chip *cgpio = gpiochip_get_data(chip); | |
89 | unsigned long flags; | |
90 | u32 int_value; | |
91 | u32 int_type; | |
92 | u32 mask = BIT(d->hwirq); | |
93 | int ret = 0; | |
94 | ||
3c938cc5 | 95 | raw_spin_lock_irqsave(&chip->bgpio_lock, flags); |
72ab2f76 JK |
96 | |
97 | int_value = ioread32(cgpio->regs + CDNS_GPIO_IRQ_VALUE) & ~mask; | |
98 | int_type = ioread32(cgpio->regs + CDNS_GPIO_IRQ_TYPE) & ~mask; | |
99 | ||
100 | /* | |
101 | * The GPIO controller doesn't have an ACK register. | |
102 | * All interrupt statuses are cleared on a status register read. | |
103 | * Don't support edge interrupts for now. | |
104 | */ | |
105 | ||
106 | if (type == IRQ_TYPE_LEVEL_HIGH) { | |
107 | int_type |= mask; | |
108 | int_value |= mask; | |
109 | } else if (type == IRQ_TYPE_LEVEL_LOW) { | |
110 | int_type |= mask; | |
111 | } else { | |
112 | ret = -EINVAL; | |
113 | goto err_irq_type; | |
114 | } | |
115 | ||
116 | iowrite32(int_value, cgpio->regs + CDNS_GPIO_IRQ_VALUE); | |
117 | iowrite32(int_type, cgpio->regs + CDNS_GPIO_IRQ_TYPE); | |
118 | ||
119 | err_irq_type: | |
3c938cc5 | 120 | raw_spin_unlock_irqrestore(&chip->bgpio_lock, flags); |
72ab2f76 JK |
121 | return ret; |
122 | } | |
123 | ||
124 | static void cdns_gpio_irq_handler(struct irq_desc *desc) | |
125 | { | |
126 | struct gpio_chip *chip = irq_desc_get_handler_data(desc); | |
127 | struct cdns_gpio_chip *cgpio = gpiochip_get_data(chip); | |
128 | struct irq_chip *irqchip = irq_desc_get_chip(desc); | |
129 | unsigned long status; | |
130 | int hwirq; | |
131 | ||
132 | chained_irq_enter(irqchip, desc); | |
133 | ||
134 | status = ioread32(cgpio->regs + CDNS_GPIO_IRQ_STATUS) & | |
135 | ~ioread32(cgpio->regs + CDNS_GPIO_IRQ_MASK); | |
136 | ||
137 | for_each_set_bit(hwirq, &status, chip->ngpio) | |
dbd1c54f | 138 | generic_handle_domain_irq(chip->irq.domain, hwirq); |
72ab2f76 JK |
139 | |
140 | chained_irq_exit(irqchip, desc); | |
141 | } | |
142 | ||
150a9880 | 143 | static const struct irq_chip cdns_gpio_irqchip = { |
72ab2f76 JK |
144 | .name = "cdns-gpio", |
145 | .irq_mask = cdns_gpio_irq_mask, | |
146 | .irq_unmask = cdns_gpio_irq_unmask, | |
150a9880 LW |
147 | .irq_set_type = cdns_gpio_irq_set_type, |
148 | .flags = IRQCHIP_IMMUTABLE, | |
149 | GPIOCHIP_IRQ_RESOURCE_HELPERS, | |
72ab2f76 JK |
150 | }; |
151 | ||
152 | static int cdns_gpio_probe(struct platform_device *pdev) | |
153 | { | |
154 | struct cdns_gpio_chip *cgpio; | |
72ab2f76 JK |
155 | int ret, irq; |
156 | u32 dir_prev; | |
157 | u32 num_gpios = 32; | |
158 | ||
159 | cgpio = devm_kzalloc(&pdev->dev, sizeof(*cgpio), GFP_KERNEL); | |
160 | if (!cgpio) | |
161 | return -ENOMEM; | |
162 | ||
b2c09588 | 163 | cgpio->regs = devm_platform_ioremap_resource(pdev, 0); |
72ab2f76 JK |
164 | if (IS_ERR(cgpio->regs)) |
165 | return PTR_ERR(cgpio->regs); | |
166 | ||
167 | of_property_read_u32(pdev->dev.of_node, "ngpios", &num_gpios); | |
168 | ||
169 | if (num_gpios > 32) { | |
170 | dev_err(&pdev->dev, "ngpios must be less or equal 32\n"); | |
171 | return -EINVAL; | |
172 | } | |
173 | ||
174 | /* | |
175 | * Set all pins as inputs by default, otherwise: | |
176 | * gpiochip_lock_as_irq: | |
177 | * tried to flag a GPIO set as output for IRQ | |
178 | * Generic GPIO driver stores the direction value internally, | |
179 | * so it needs to be changed before bgpio_init() is called. | |
180 | */ | |
181 | dir_prev = ioread32(cgpio->regs + CDNS_GPIO_DIRECTION_MODE); | |
182 | iowrite32(GENMASK(num_gpios - 1, 0), | |
183 | cgpio->regs + CDNS_GPIO_DIRECTION_MODE); | |
184 | ||
185 | ret = bgpio_init(&cgpio->gc, &pdev->dev, 4, | |
186 | cgpio->regs + CDNS_GPIO_INPUT_VALUE, | |
187 | cgpio->regs + CDNS_GPIO_OUTPUT_VALUE, | |
188 | NULL, | |
189 | NULL, | |
190 | cgpio->regs + CDNS_GPIO_DIRECTION_MODE, | |
191 | BGPIOF_READ_OUTPUT_REG_SET); | |
192 | if (ret) { | |
193 | dev_err(&pdev->dev, "Failed to register generic gpio, %d\n", | |
194 | ret); | |
195 | goto err_revert_dir; | |
196 | } | |
197 | ||
198 | cgpio->gc.label = dev_name(&pdev->dev); | |
199 | cgpio->gc.ngpio = num_gpios; | |
200 | cgpio->gc.parent = &pdev->dev; | |
201 | cgpio->gc.base = -1; | |
202 | cgpio->gc.owner = THIS_MODULE; | |
203 | cgpio->gc.request = cdns_gpio_request; | |
204 | cgpio->gc.free = cdns_gpio_free; | |
205 | ||
206 | cgpio->pclk = devm_clk_get(&pdev->dev, NULL); | |
207 | if (IS_ERR(cgpio->pclk)) { | |
208 | ret = PTR_ERR(cgpio->pclk); | |
209 | dev_err(&pdev->dev, | |
210 | "Failed to retrieve peripheral clock, %d\n", ret); | |
211 | goto err_revert_dir; | |
212 | } | |
213 | ||
214 | ret = clk_prepare_enable(cgpio->pclk); | |
215 | if (ret) { | |
216 | dev_err(&pdev->dev, | |
217 | "Failed to enable the peripheral clock, %d\n", ret); | |
218 | goto err_revert_dir; | |
219 | } | |
220 | ||
72ab2f76 | 221 | /* |
607a0dcd | 222 | * Optional irq_chip support |
72ab2f76 JK |
223 | */ |
224 | irq = platform_get_irq(pdev, 0); | |
225 | if (irq >= 0) { | |
607a0dcd LW |
226 | struct gpio_irq_chip *girq; |
227 | ||
228 | girq = &cgpio->gc.irq; | |
150a9880 | 229 | gpio_irq_chip_set_chip(girq, &cdns_gpio_irqchip); |
607a0dcd LW |
230 | girq->parent_handler = cdns_gpio_irq_handler; |
231 | girq->num_parents = 1; | |
232 | girq->parents = devm_kcalloc(&pdev->dev, 1, | |
233 | sizeof(*girq->parents), | |
234 | GFP_KERNEL); | |
235 | if (!girq->parents) { | |
236 | ret = -ENOMEM; | |
72ab2f76 JK |
237 | goto err_disable_clk; |
238 | } | |
607a0dcd LW |
239 | girq->parents[0] = irq; |
240 | girq->default_type = IRQ_TYPE_NONE; | |
241 | girq->handler = handle_level_irq; | |
242 | } | |
243 | ||
244 | ret = devm_gpiochip_add_data(&pdev->dev, &cgpio->gc, cgpio); | |
245 | if (ret < 0) { | |
246 | dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret); | |
247 | goto err_disable_clk; | |
72ab2f76 JK |
248 | } |
249 | ||
250 | cgpio->bypass_orig = ioread32(cgpio->regs + CDNS_GPIO_BYPASS_MODE); | |
251 | ||
252 | /* | |
253 | * Enable gpio outputs, ignored for input direction | |
254 | */ | |
255 | iowrite32(GENMASK(num_gpios - 1, 0), | |
256 | cgpio->regs + CDNS_GPIO_OUTPUT_EN); | |
257 | iowrite32(0, cgpio->regs + CDNS_GPIO_BYPASS_MODE); | |
258 | ||
259 | platform_set_drvdata(pdev, cgpio); | |
260 | return 0; | |
261 | ||
262 | err_disable_clk: | |
263 | clk_disable_unprepare(cgpio->pclk); | |
264 | ||
265 | err_revert_dir: | |
266 | iowrite32(dir_prev, cgpio->regs + CDNS_GPIO_DIRECTION_MODE); | |
267 | ||
268 | return ret; | |
269 | } | |
270 | ||
271 | static int cdns_gpio_remove(struct platform_device *pdev) | |
272 | { | |
273 | struct cdns_gpio_chip *cgpio = platform_get_drvdata(pdev); | |
274 | ||
275 | iowrite32(cgpio->bypass_orig, cgpio->regs + CDNS_GPIO_BYPASS_MODE); | |
276 | clk_disable_unprepare(cgpio->pclk); | |
277 | ||
278 | return 0; | |
279 | } | |
280 | ||
281 | static const struct of_device_id cdns_of_ids[] = { | |
282 | { .compatible = "cdns,gpio-r1p02" }, | |
283 | { /* sentinel */ }, | |
284 | }; | |
1e948b17 | 285 | MODULE_DEVICE_TABLE(of, cdns_of_ids); |
72ab2f76 JK |
286 | |
287 | static struct platform_driver cdns_gpio_driver = { | |
288 | .driver = { | |
289 | .name = "cdns-gpio", | |
290 | .of_match_table = cdns_of_ids, | |
291 | }, | |
292 | .probe = cdns_gpio_probe, | |
293 | .remove = cdns_gpio_remove, | |
294 | }; | |
295 | module_platform_driver(cdns_gpio_driver); | |
296 | ||
297 | MODULE_AUTHOR("Jan Kotas <[email protected]>"); | |
298 | MODULE_DESCRIPTION("Cadence GPIO driver"); | |
299 | MODULE_LICENSE("GPL v2"); | |
300 | MODULE_ALIAS("platform:cdns-gpio"); |