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
22static 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
29static 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
37static 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
45static 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
55static 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
68static 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
78static 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
90static 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
100static 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
108static 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
128static 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
157static 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
166static int bcma_gpio_irq_init(struct bcma_drv_cc *cc)
167{
168	return 0;
169}
170
171static void bcma_gpio_irq_exit(struct bcma_drv_cc *cc)
172{
173}
174#endif
175
176int 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
231int 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