xref: /openbmc/linux/drivers/bcma/driver_gpio.c (revision 55549d6a)
1 /*
2  * Broadcom specific AMBA
3  * GPIO driver
4  *
5  * Copyright 2011, Broadcom Corporation
6  * Copyright 2012, Hauke Mehrtens <hauke@hauke-m.de>
7  *
8  * Licensed under the GNU/GPL. See COPYING for details.
9  */
10 
11 #include <linux/gpio/driver.h>
12 #include <linux/interrupt.h>
13 #include <linux/export.h>
14 #include <linux/property.h>
15 
16 #include <linux/bcma/bcma.h>
17 
18 #include "bcma_private.h"
19 
20 #define BCMA_GPIO_MAX_PINS	32
21 
bcma_gpio_get_value(struct gpio_chip * chip,unsigned gpio)22 static int bcma_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
23 {
24 	struct bcma_drv_cc *cc = gpiochip_get_data(chip);
25 
26 	return !!bcma_chipco_gpio_in(cc, 1 << gpio);
27 }
28 
bcma_gpio_set_value(struct gpio_chip * chip,unsigned gpio,int value)29 static void bcma_gpio_set_value(struct gpio_chip *chip, unsigned gpio,
30 				int value)
31 {
32 	struct bcma_drv_cc *cc = gpiochip_get_data(chip);
33 
34 	bcma_chipco_gpio_out(cc, 1 << gpio, value ? 1 << gpio : 0);
35 }
36 
bcma_gpio_direction_input(struct gpio_chip * chip,unsigned gpio)37 static int bcma_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
38 {
39 	struct bcma_drv_cc *cc = gpiochip_get_data(chip);
40 
41 	bcma_chipco_gpio_outen(cc, 1 << gpio, 0);
42 	return 0;
43 }
44 
bcma_gpio_direction_output(struct gpio_chip * chip,unsigned gpio,int value)45 static int bcma_gpio_direction_output(struct gpio_chip *chip, unsigned gpio,
46 				      int value)
47 {
48 	struct bcma_drv_cc *cc = gpiochip_get_data(chip);
49 
50 	bcma_chipco_gpio_outen(cc, 1 << gpio, 1 << gpio);
51 	bcma_chipco_gpio_out(cc, 1 << gpio, value ? 1 << gpio : 0);
52 	return 0;
53 }
54 
bcma_gpio_request(struct gpio_chip * chip,unsigned gpio)55 static int bcma_gpio_request(struct gpio_chip *chip, unsigned gpio)
56 {
57 	struct bcma_drv_cc *cc = gpiochip_get_data(chip);
58 
59 	bcma_chipco_gpio_control(cc, 1 << gpio, 0);
60 	/* clear pulldown */
61 	bcma_chipco_gpio_pulldown(cc, 1 << gpio, 0);
62 	/* Set pullup */
63 	bcma_chipco_gpio_pullup(cc, 1 << gpio, 1 << gpio);
64 
65 	return 0;
66 }
67 
bcma_gpio_free(struct gpio_chip * chip,unsigned gpio)68 static void bcma_gpio_free(struct gpio_chip *chip, unsigned gpio)
69 {
70 	struct bcma_drv_cc *cc = gpiochip_get_data(chip);
71 
72 	/* clear pullup */
73 	bcma_chipco_gpio_pullup(cc, 1 << gpio, 0);
74 }
75 
76 #if IS_BUILTIN(CONFIG_BCM47XX) || IS_BUILTIN(CONFIG_ARCH_BCM_5301X)
77 
bcma_gpio_irq_unmask(struct irq_data * d)78 static void bcma_gpio_irq_unmask(struct irq_data *d)
79 {
80 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
81 	struct bcma_drv_cc *cc = gpiochip_get_data(gc);
82 	int gpio = irqd_to_hwirq(d);
83 	u32 val = bcma_chipco_gpio_in(cc, BIT(gpio));
84 
85 	gpiochip_enable_irq(gc, gpio);
86 	bcma_chipco_gpio_polarity(cc, BIT(gpio), val);
87 	bcma_chipco_gpio_intmask(cc, BIT(gpio), BIT(gpio));
88 }
89 
bcma_gpio_irq_mask(struct irq_data * d)90 static void bcma_gpio_irq_mask(struct irq_data *d)
91 {
92 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
93 	struct bcma_drv_cc *cc = gpiochip_get_data(gc);
94 	int gpio = irqd_to_hwirq(d);
95 
96 	bcma_chipco_gpio_intmask(cc, BIT(gpio), 0);
97 	gpiochip_disable_irq(gc, gpio);
98 }
99 
100 static const struct irq_chip bcma_gpio_irq_chip = {
101 	.name		= "BCMA-GPIO",
102 	.irq_mask	= bcma_gpio_irq_mask,
103 	.irq_unmask	= bcma_gpio_irq_unmask,
104 	.flags		= IRQCHIP_IMMUTABLE,
105 	GPIOCHIP_IRQ_RESOURCE_HELPERS,
106 };
107 
bcma_gpio_irq_handler(int irq,void * dev_id)108 static irqreturn_t bcma_gpio_irq_handler(int irq, void *dev_id)
109 {
110 	struct bcma_drv_cc *cc = dev_id;
111 	struct gpio_chip *gc = &cc->gpio;
112 	u32 val = bcma_cc_read32(cc, BCMA_CC_GPIOIN);
113 	u32 mask = bcma_cc_read32(cc, BCMA_CC_GPIOIRQ);
114 	u32 pol = bcma_cc_read32(cc, BCMA_CC_GPIOPOL);
115 	unsigned long irqs = (val ^ pol) & mask;
116 	int gpio;
117 
118 	if (!irqs)
119 		return IRQ_NONE;
120 
121 	for_each_set_bit(gpio, &irqs, gc->ngpio)
122 		generic_handle_domain_irq_safe(gc->irq.domain, gpio);
123 	bcma_chipco_gpio_polarity(cc, irqs, val & irqs);
124 
125 	return IRQ_HANDLED;
126 }
127 
bcma_gpio_irq_init(struct bcma_drv_cc * cc)128 static int bcma_gpio_irq_init(struct bcma_drv_cc *cc)
129 {
130 	struct gpio_chip *chip = &cc->gpio;
131 	struct gpio_irq_chip *girq = &chip->irq;
132 	int hwirq, err;
133 
134 	if (cc->core->bus->hosttype != BCMA_HOSTTYPE_SOC)
135 		return 0;
136 
137 	hwirq = bcma_core_irq(cc->core, 0);
138 	err = request_irq(hwirq, bcma_gpio_irq_handler, IRQF_SHARED, "gpio",
139 			  cc);
140 	if (err)
141 		return err;
142 
143 	bcma_chipco_gpio_intmask(cc, ~0, 0);
144 	bcma_cc_set32(cc, BCMA_CC_IRQMASK, BCMA_CC_IRQ_GPIO);
145 
146 	gpio_irq_chip_set_chip(girq, &bcma_gpio_irq_chip);
147 	/* This will let us handle the parent IRQ in the driver */
148 	girq->parent_handler = NULL;
149 	girq->num_parents = 0;
150 	girq->parents = NULL;
151 	girq->default_type = IRQ_TYPE_NONE;
152 	girq->handler = handle_simple_irq;
153 
154 	return 0;
155 }
156 
bcma_gpio_irq_exit(struct bcma_drv_cc * cc)157 static void bcma_gpio_irq_exit(struct bcma_drv_cc *cc)
158 {
159 	if (cc->core->bus->hosttype != BCMA_HOSTTYPE_SOC)
160 		return;
161 
162 	bcma_cc_mask32(cc, BCMA_CC_IRQMASK, ~BCMA_CC_IRQ_GPIO);
163 	free_irq(bcma_core_irq(cc->core, 0), cc);
164 }
165 #else
bcma_gpio_irq_init(struct bcma_drv_cc * cc)166 static int bcma_gpio_irq_init(struct bcma_drv_cc *cc)
167 {
168 	return 0;
169 }
170 
bcma_gpio_irq_exit(struct bcma_drv_cc * cc)171 static void bcma_gpio_irq_exit(struct bcma_drv_cc *cc)
172 {
173 }
174 #endif
175 
bcma_gpio_init(struct bcma_drv_cc * cc)176 int bcma_gpio_init(struct bcma_drv_cc *cc)
177 {
178 	struct bcma_bus *bus = cc->core->bus;
179 	struct gpio_chip *chip = &cc->gpio;
180 	int err;
181 
182 	chip->label		= "bcma_gpio";
183 	chip->owner		= THIS_MODULE;
184 	chip->request		= bcma_gpio_request;
185 	chip->free		= bcma_gpio_free;
186 	chip->get		= bcma_gpio_get_value;
187 	chip->set		= bcma_gpio_set_value;
188 	chip->direction_input	= bcma_gpio_direction_input;
189 	chip->direction_output	= bcma_gpio_direction_output;
190 	chip->parent		= bus->dev;
191 	chip->fwnode		= dev_fwnode(&cc->core->dev);
192 
193 	switch (bus->chipinfo.id) {
194 	case BCMA_CHIP_ID_BCM4707:
195 	case BCMA_CHIP_ID_BCM5357:
196 	case BCMA_CHIP_ID_BCM53572:
197 	case BCMA_CHIP_ID_BCM53573:
198 	case BCMA_CHIP_ID_BCM47094:
199 		chip->ngpio	= 32;
200 		break;
201 	default:
202 		chip->ngpio	= 16;
203 	}
204 
205 	/*
206 	 * Register SoC GPIO devices with absolute GPIO pin base.
207 	 * On MIPS, we don't have Device Tree and we can't use relative (per chip)
208 	 * GPIO numbers.
209 	 * On some ARM devices, user space may want to access some system GPIO
210 	 * pins directly, which is easier to do with a predictable GPIO base.
211 	 */
212 	if (IS_BUILTIN(CONFIG_BCM47XX) ||
213 	    cc->core->bus->hosttype == BCMA_HOSTTYPE_SOC)
214 		chip->base		= bus->num * BCMA_GPIO_MAX_PINS;
215 	else
216 		chip->base		= -1;
217 
218 	err = bcma_gpio_irq_init(cc);
219 	if (err)
220 		return err;
221 
222 	err = gpiochip_add_data(chip, cc);
223 	if (err) {
224 		bcma_gpio_irq_exit(cc);
225 		return err;
226 	}
227 
228 	return 0;
229 }
230 
bcma_gpio_unregister(struct bcma_drv_cc * cc)231 int bcma_gpio_unregister(struct bcma_drv_cc *cc)
232 {
233 	bcma_gpio_irq_exit(cc);
234 	gpiochip_remove(&cc->gpio);
235 	return 0;
236 }
237