xref: /openbmc/linux/drivers/gpio/gpio-sa1100.c (revision fcbd8037)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * linux/arch/arm/mach-sa1100/gpio.c
4  *
5  * Generic SA-1100 GPIO handling
6  */
7 #include <linux/gpio/driver.h>
8 #include <linux/init.h>
9 #include <linux/module.h>
10 #include <linux/io.h>
11 #include <linux/syscore_ops.h>
12 #include <soc/sa1100/pwer.h>
13 #include <mach/hardware.h>
14 #include <mach/irqs.h>
15 
16 struct sa1100_gpio_chip {
17 	struct gpio_chip chip;
18 	void __iomem *membase;
19 	int irqbase;
20 	u32 irqmask;
21 	u32 irqrising;
22 	u32 irqfalling;
23 	u32 irqwake;
24 };
25 
26 #define sa1100_gpio_chip(x) container_of(x, struct sa1100_gpio_chip, chip)
27 
28 enum {
29 	R_GPLR = 0x00,
30 	R_GPDR = 0x04,
31 	R_GPSR = 0x08,
32 	R_GPCR = 0x0c,
33 	R_GRER = 0x10,
34 	R_GFER = 0x14,
35 	R_GEDR = 0x18,
36 	R_GAFR = 0x1c,
37 };
38 
39 static int sa1100_gpio_get(struct gpio_chip *chip, unsigned offset)
40 {
41 	return readl_relaxed(sa1100_gpio_chip(chip)->membase + R_GPLR) &
42 		BIT(offset);
43 }
44 
45 static void sa1100_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
46 {
47 	int reg = value ? R_GPSR : R_GPCR;
48 
49 	writel_relaxed(BIT(offset), sa1100_gpio_chip(chip)->membase + reg);
50 }
51 
52 static int sa1100_get_direction(struct gpio_chip *chip, unsigned offset)
53 {
54 	void __iomem *gpdr = sa1100_gpio_chip(chip)->membase + R_GPDR;
55 
56 	return !(readl_relaxed(gpdr) & BIT(offset));
57 }
58 
59 static int sa1100_direction_input(struct gpio_chip *chip, unsigned offset)
60 {
61 	void __iomem *gpdr = sa1100_gpio_chip(chip)->membase + R_GPDR;
62 	unsigned long flags;
63 
64 	local_irq_save(flags);
65 	writel_relaxed(readl_relaxed(gpdr) & ~BIT(offset), gpdr);
66 	local_irq_restore(flags);
67 
68 	return 0;
69 }
70 
71 static int sa1100_direction_output(struct gpio_chip *chip, unsigned offset, int value)
72 {
73 	void __iomem *gpdr = sa1100_gpio_chip(chip)->membase + R_GPDR;
74 	unsigned long flags;
75 
76 	local_irq_save(flags);
77 	sa1100_gpio_set(chip, offset, value);
78 	writel_relaxed(readl_relaxed(gpdr) | BIT(offset), gpdr);
79 	local_irq_restore(flags);
80 
81 	return 0;
82 }
83 
84 static int sa1100_to_irq(struct gpio_chip *chip, unsigned offset)
85 {
86 	return sa1100_gpio_chip(chip)->irqbase + offset;
87 }
88 
89 static struct sa1100_gpio_chip sa1100_gpio_chip = {
90 	.chip = {
91 		.label			= "gpio",
92 		.get_direction		= sa1100_get_direction,
93 		.direction_input	= sa1100_direction_input,
94 		.direction_output	= sa1100_direction_output,
95 		.set			= sa1100_gpio_set,
96 		.get			= sa1100_gpio_get,
97 		.to_irq			= sa1100_to_irq,
98 		.base			= 0,
99 		.ngpio			= GPIO_MAX + 1,
100 	},
101 	.membase = (void *)&GPLR,
102 	.irqbase = IRQ_GPIO0,
103 };
104 
105 /*
106  * SA1100 GPIO edge detection for IRQs:
107  * IRQs are generated on Falling-Edge, Rising-Edge, or both.
108  * Use this instead of directly setting GRER/GFER.
109  */
110 static void sa1100_update_edge_regs(struct sa1100_gpio_chip *sgc)
111 {
112 	void *base = sgc->membase;
113 	u32 grer, gfer;
114 
115 	grer = sgc->irqrising & sgc->irqmask;
116 	gfer = sgc->irqfalling & sgc->irqmask;
117 
118 	writel_relaxed(grer, base + R_GRER);
119 	writel_relaxed(gfer, base + R_GFER);
120 }
121 
122 static int sa1100_gpio_type(struct irq_data *d, unsigned int type)
123 {
124 	struct sa1100_gpio_chip *sgc = irq_data_get_irq_chip_data(d);
125 	unsigned int mask = BIT(d->hwirq);
126 
127 	if (type == IRQ_TYPE_PROBE) {
128 		if ((sgc->irqrising | sgc->irqfalling) & mask)
129 			return 0;
130 		type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
131 	}
132 
133 	if (type & IRQ_TYPE_EDGE_RISING)
134 		sgc->irqrising |= mask;
135 	else
136 		sgc->irqrising &= ~mask;
137 	if (type & IRQ_TYPE_EDGE_FALLING)
138 		sgc->irqfalling |= mask;
139 	else
140 		sgc->irqfalling &= ~mask;
141 
142 	sa1100_update_edge_regs(sgc);
143 
144 	return 0;
145 }
146 
147 /*
148  * GPIO IRQs must be acknowledged.
149  */
150 static void sa1100_gpio_ack(struct irq_data *d)
151 {
152 	struct sa1100_gpio_chip *sgc = irq_data_get_irq_chip_data(d);
153 
154 	writel_relaxed(BIT(d->hwirq), sgc->membase + R_GEDR);
155 }
156 
157 static void sa1100_gpio_mask(struct irq_data *d)
158 {
159 	struct sa1100_gpio_chip *sgc = irq_data_get_irq_chip_data(d);
160 	unsigned int mask = BIT(d->hwirq);
161 
162 	sgc->irqmask &= ~mask;
163 
164 	sa1100_update_edge_regs(sgc);
165 }
166 
167 static void sa1100_gpio_unmask(struct irq_data *d)
168 {
169 	struct sa1100_gpio_chip *sgc = irq_data_get_irq_chip_data(d);
170 	unsigned int mask = BIT(d->hwirq);
171 
172 	sgc->irqmask |= mask;
173 
174 	sa1100_update_edge_regs(sgc);
175 }
176 
177 static int sa1100_gpio_wake(struct irq_data *d, unsigned int on)
178 {
179 	struct sa1100_gpio_chip *sgc = irq_data_get_irq_chip_data(d);
180 	int ret = sa11x0_gpio_set_wake(d->hwirq, on);
181 	if (!ret) {
182 		if (on)
183 			sgc->irqwake |= BIT(d->hwirq);
184 		else
185 			sgc->irqwake &= ~BIT(d->hwirq);
186 	}
187 	return ret;
188 }
189 
190 /*
191  * This is for GPIO IRQs
192  */
193 static struct irq_chip sa1100_gpio_irq_chip = {
194 	.name		= "GPIO",
195 	.irq_ack	= sa1100_gpio_ack,
196 	.irq_mask	= sa1100_gpio_mask,
197 	.irq_unmask	= sa1100_gpio_unmask,
198 	.irq_set_type	= sa1100_gpio_type,
199 	.irq_set_wake	= sa1100_gpio_wake,
200 };
201 
202 static int sa1100_gpio_irqdomain_map(struct irq_domain *d,
203 		unsigned int irq, irq_hw_number_t hwirq)
204 {
205 	struct sa1100_gpio_chip *sgc = d->host_data;
206 
207 	irq_set_chip_data(irq, sgc);
208 	irq_set_chip_and_handler(irq, &sa1100_gpio_irq_chip, handle_edge_irq);
209 	irq_set_probe(irq);
210 
211 	return 0;
212 }
213 
214 static const struct irq_domain_ops sa1100_gpio_irqdomain_ops = {
215 	.map = sa1100_gpio_irqdomain_map,
216 	.xlate = irq_domain_xlate_onetwocell,
217 };
218 
219 static struct irq_domain *sa1100_gpio_irqdomain;
220 
221 /*
222  * IRQ 0-11 (GPIO) handler.  We enter here with the
223  * irq_controller_lock held, and IRQs disabled.  Decode the IRQ
224  * and call the handler.
225  */
226 static void sa1100_gpio_handler(struct irq_desc *desc)
227 {
228 	struct sa1100_gpio_chip *sgc = irq_desc_get_handler_data(desc);
229 	unsigned int irq, mask;
230 	void __iomem *gedr = sgc->membase + R_GEDR;
231 
232 	mask = readl_relaxed(gedr);
233 	do {
234 		/*
235 		 * clear down all currently active IRQ sources.
236 		 * We will be processing them all.
237 		 */
238 		writel_relaxed(mask, gedr);
239 
240 		irq = sgc->irqbase;
241 		do {
242 			if (mask & 1)
243 				generic_handle_irq(irq);
244 			mask >>= 1;
245 			irq++;
246 		} while (mask);
247 
248 		mask = readl_relaxed(gedr);
249 	} while (mask);
250 }
251 
252 static int sa1100_gpio_suspend(void)
253 {
254 	struct sa1100_gpio_chip *sgc = &sa1100_gpio_chip;
255 
256 	/*
257 	 * Set the appropriate edges for wakeup.
258 	 */
259 	writel_relaxed(sgc->irqwake & sgc->irqrising, sgc->membase + R_GRER);
260 	writel_relaxed(sgc->irqwake & sgc->irqfalling, sgc->membase + R_GFER);
261 
262 	/*
263 	 * Clear any pending GPIO interrupts.
264 	 */
265 	writel_relaxed(readl_relaxed(sgc->membase + R_GEDR),
266 		       sgc->membase + R_GEDR);
267 
268 	return 0;
269 }
270 
271 static void sa1100_gpio_resume(void)
272 {
273 	sa1100_update_edge_regs(&sa1100_gpio_chip);
274 }
275 
276 static struct syscore_ops sa1100_gpio_syscore_ops = {
277 	.suspend	= sa1100_gpio_suspend,
278 	.resume		= sa1100_gpio_resume,
279 };
280 
281 static int __init sa1100_gpio_init_devicefs(void)
282 {
283 	register_syscore_ops(&sa1100_gpio_syscore_ops);
284 	return 0;
285 }
286 
287 device_initcall(sa1100_gpio_init_devicefs);
288 
289 static const int sa1100_gpio_irqs[] __initconst = {
290 	/* Install handlers for GPIO 0-10 edge detect interrupts */
291 	IRQ_GPIO0_SC,
292 	IRQ_GPIO1_SC,
293 	IRQ_GPIO2_SC,
294 	IRQ_GPIO3_SC,
295 	IRQ_GPIO4_SC,
296 	IRQ_GPIO5_SC,
297 	IRQ_GPIO6_SC,
298 	IRQ_GPIO7_SC,
299 	IRQ_GPIO8_SC,
300 	IRQ_GPIO9_SC,
301 	IRQ_GPIO10_SC,
302 	/* Install handler for GPIO 11-27 edge detect interrupts */
303 	IRQ_GPIO11_27,
304 };
305 
306 void __init sa1100_init_gpio(void)
307 {
308 	struct sa1100_gpio_chip *sgc = &sa1100_gpio_chip;
309 	int i;
310 
311 	/* clear all GPIO edge detects */
312 	writel_relaxed(0, sgc->membase + R_GFER);
313 	writel_relaxed(0, sgc->membase + R_GRER);
314 	writel_relaxed(-1, sgc->membase + R_GEDR);
315 
316 	gpiochip_add_data(&sa1100_gpio_chip.chip, NULL);
317 
318 	sa1100_gpio_irqdomain = irq_domain_add_simple(NULL,
319 			28, IRQ_GPIO0,
320 			&sa1100_gpio_irqdomain_ops, sgc);
321 
322 	for (i = 0; i < ARRAY_SIZE(sa1100_gpio_irqs); i++)
323 		irq_set_chained_handler_and_data(sa1100_gpio_irqs[i],
324 						 sa1100_gpio_handler, sgc);
325 }
326