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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
32struct cdns_gpio_chip {
33 struct gpio_chip gc;
34 struct clk *pclk;
35 void __iomem *regs;
36 u32 bypass_orig;
37};
38
39static 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
44 spin_lock_irqsave(&chip->bgpio_lock, flags);
45
46 iowrite32(ioread32(cgpio->regs + CDNS_GPIO_BYPASS_MODE) & ~BIT(offset),
47 cgpio->regs + CDNS_GPIO_BYPASS_MODE);
48
49 spin_unlock_irqrestore(&chip->bgpio_lock, flags);
50 return 0;
51}
52
53static 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
58 spin_lock_irqsave(&chip->bgpio_lock, flags);
59
60 iowrite32(ioread32(cgpio->regs + CDNS_GPIO_BYPASS_MODE) |
61 (BIT(offset) & cgpio->bypass_orig),
62 cgpio->regs + CDNS_GPIO_BYPASS_MODE);
63
64 spin_unlock_irqrestore(&chip->bgpio_lock, flags);
65}
66
67static 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);
73}
74
75static void cdns_gpio_irq_unmask(struct irq_data *d)
76{
77 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
78 struct cdns_gpio_chip *cgpio = gpiochip_get_data(chip);
79
80 iowrite32(BIT(d->hwirq), cgpio->regs + CDNS_GPIO_IRQ_EN);
81}
82
83static int cdns_gpio_irq_set_type(struct irq_data *d, unsigned int type)
84{
85 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
86 struct cdns_gpio_chip *cgpio = gpiochip_get_data(chip);
87 unsigned long flags;
88 u32 int_value;
89 u32 int_type;
90 u32 mask = BIT(d->hwirq);
91 int ret = 0;
92
93 spin_lock_irqsave(&chip->bgpio_lock, flags);
94
95 int_value = ioread32(cgpio->regs + CDNS_GPIO_IRQ_VALUE) & ~mask;
96 int_type = ioread32(cgpio->regs + CDNS_GPIO_IRQ_TYPE) & ~mask;
97
98
99
100
101
102
103
104 if (type == IRQ_TYPE_LEVEL_HIGH) {
105 int_type |= mask;
106 int_value |= mask;
107 } else if (type == IRQ_TYPE_LEVEL_LOW) {
108 int_type |= mask;
109 } else {
110 ret = -EINVAL;
111 goto err_irq_type;
112 }
113
114 iowrite32(int_value, cgpio->regs + CDNS_GPIO_IRQ_VALUE);
115 iowrite32(int_type, cgpio->regs + CDNS_GPIO_IRQ_TYPE);
116
117err_irq_type:
118 spin_unlock_irqrestore(&chip->bgpio_lock, flags);
119 return ret;
120}
121
122static void cdns_gpio_irq_handler(struct irq_desc *desc)
123{
124 struct gpio_chip *chip = irq_desc_get_handler_data(desc);
125 struct cdns_gpio_chip *cgpio = gpiochip_get_data(chip);
126 struct irq_chip *irqchip = irq_desc_get_chip(desc);
127 unsigned long status;
128 int hwirq;
129
130 chained_irq_enter(irqchip, desc);
131
132 status = ioread32(cgpio->regs + CDNS_GPIO_IRQ_STATUS) &
133 ~ioread32(cgpio->regs + CDNS_GPIO_IRQ_MASK);
134
135 for_each_set_bit(hwirq, &status, chip->ngpio)
136 generic_handle_domain_irq(chip->irq.domain, hwirq);
137
138 chained_irq_exit(irqchip, desc);
139}
140
141static struct irq_chip cdns_gpio_irqchip = {
142 .name = "cdns-gpio",
143 .irq_mask = cdns_gpio_irq_mask,
144 .irq_unmask = cdns_gpio_irq_unmask,
145 .irq_set_type = cdns_gpio_irq_set_type
146};
147
148static int cdns_gpio_probe(struct platform_device *pdev)
149{
150 struct cdns_gpio_chip *cgpio;
151 int ret, irq;
152 u32 dir_prev;
153 u32 num_gpios = 32;
154
155 cgpio = devm_kzalloc(&pdev->dev, sizeof(*cgpio), GFP_KERNEL);
156 if (!cgpio)
157 return -ENOMEM;
158
159 cgpio->regs = devm_platform_ioremap_resource(pdev, 0);
160 if (IS_ERR(cgpio->regs))
161 return PTR_ERR(cgpio->regs);
162
163 of_property_read_u32(pdev->dev.of_node, "ngpios", &num_gpios);
164
165 if (num_gpios > 32) {
166 dev_err(&pdev->dev, "ngpios must be less or equal 32\n");
167 return -EINVAL;
168 }
169
170
171
172
173
174
175
176
177 dir_prev = ioread32(cgpio->regs + CDNS_GPIO_DIRECTION_MODE);
178 iowrite32(GENMASK(num_gpios - 1, 0),
179 cgpio->regs + CDNS_GPIO_DIRECTION_MODE);
180
181 ret = bgpio_init(&cgpio->gc, &pdev->dev, 4,
182 cgpio->regs + CDNS_GPIO_INPUT_VALUE,
183 cgpio->regs + CDNS_GPIO_OUTPUT_VALUE,
184 NULL,
185 NULL,
186 cgpio->regs + CDNS_GPIO_DIRECTION_MODE,
187 BGPIOF_READ_OUTPUT_REG_SET);
188 if (ret) {
189 dev_err(&pdev->dev, "Failed to register generic gpio, %d\n",
190 ret);
191 goto err_revert_dir;
192 }
193
194 cgpio->gc.label = dev_name(&pdev->dev);
195 cgpio->gc.ngpio = num_gpios;
196 cgpio->gc.parent = &pdev->dev;
197 cgpio->gc.base = -1;
198 cgpio->gc.owner = THIS_MODULE;
199 cgpio->gc.request = cdns_gpio_request;
200 cgpio->gc.free = cdns_gpio_free;
201
202 cgpio->pclk = devm_clk_get(&pdev->dev, NULL);
203 if (IS_ERR(cgpio->pclk)) {
204 ret = PTR_ERR(cgpio->pclk);
205 dev_err(&pdev->dev,
206 "Failed to retrieve peripheral clock, %d\n", ret);
207 goto err_revert_dir;
208 }
209
210 ret = clk_prepare_enable(cgpio->pclk);
211 if (ret) {
212 dev_err(&pdev->dev,
213 "Failed to enable the peripheral clock, %d\n", ret);
214 goto err_revert_dir;
215 }
216
217
218
219
220 irq = platform_get_irq(pdev, 0);
221 if (irq >= 0) {
222 struct gpio_irq_chip *girq;
223
224 girq = &cgpio->gc.irq;
225 girq->chip = &cdns_gpio_irqchip;
226 girq->parent_handler = cdns_gpio_irq_handler;
227 girq->num_parents = 1;
228 girq->parents = devm_kcalloc(&pdev->dev, 1,
229 sizeof(*girq->parents),
230 GFP_KERNEL);
231 if (!girq->parents) {
232 ret = -ENOMEM;
233 goto err_disable_clk;
234 }
235 girq->parents[0] = irq;
236 girq->default_type = IRQ_TYPE_NONE;
237 girq->handler = handle_level_irq;
238 }
239
240 ret = devm_gpiochip_add_data(&pdev->dev, &cgpio->gc, cgpio);
241 if (ret < 0) {
242 dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
243 goto err_disable_clk;
244 }
245
246 cgpio->bypass_orig = ioread32(cgpio->regs + CDNS_GPIO_BYPASS_MODE);
247
248
249
250
251 iowrite32(GENMASK(num_gpios - 1, 0),
252 cgpio->regs + CDNS_GPIO_OUTPUT_EN);
253 iowrite32(0, cgpio->regs + CDNS_GPIO_BYPASS_MODE);
254
255 platform_set_drvdata(pdev, cgpio);
256 return 0;
257
258err_disable_clk:
259 clk_disable_unprepare(cgpio->pclk);
260
261err_revert_dir:
262 iowrite32(dir_prev, cgpio->regs + CDNS_GPIO_DIRECTION_MODE);
263
264 return ret;
265}
266
267static int cdns_gpio_remove(struct platform_device *pdev)
268{
269 struct cdns_gpio_chip *cgpio = platform_get_drvdata(pdev);
270
271 iowrite32(cgpio->bypass_orig, cgpio->regs + CDNS_GPIO_BYPASS_MODE);
272 clk_disable_unprepare(cgpio->pclk);
273
274 return 0;
275}
276
277static const struct of_device_id cdns_of_ids[] = {
278 { .compatible = "cdns,gpio-r1p02" },
279 { },
280};
281MODULE_DEVICE_TABLE(of, cdns_of_ids);
282
283static struct platform_driver cdns_gpio_driver = {
284 .driver = {
285 .name = "cdns-gpio",
286 .of_match_table = cdns_of_ids,
287 },
288 .probe = cdns_gpio_probe,
289 .remove = cdns_gpio_remove,
290};
291module_platform_driver(cdns_gpio_driver);
292
293MODULE_AUTHOR("Jan Kotas <jank@cadence.com>");
294MODULE_DESCRIPTION("Cadence GPIO driver");
295MODULE_LICENSE("GPL v2");
296MODULE_ALIAS("platform:cdns-gpio");
297
