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/bcma/bcma.h>
15
16#include "bcma_private.h"
17
18#define BCMA_GPIO_MAX_PINS	32
19
20static inline struct bcma_drv_cc *bcma_gpio_get_cc(struct gpio_chip *chip)
21{
22	return container_of(chip, struct bcma_drv_cc, gpio);
23}
24
25static int bcma_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
26{
27	struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
28
29	return !!bcma_chipco_gpio_in(cc, 1 << gpio);
30}
31
32static void bcma_gpio_set_value(struct gpio_chip *chip, unsigned gpio,
33				int value)
34{
35	struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
36
37	bcma_chipco_gpio_out(cc, 1 << gpio, value ? 1 << gpio : 0);
38}
39
40static int bcma_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
41{
42	struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
43
44	bcma_chipco_gpio_outen(cc, 1 << gpio, 0);
45	return 0;
46}
47
48static int bcma_gpio_direction_output(struct gpio_chip *chip, unsigned gpio,
49				      int value)
50{
51	struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
52
53	bcma_chipco_gpio_outen(cc, 1 << gpio, 1 << gpio);
54	bcma_chipco_gpio_out(cc, 1 << gpio, value ? 1 << gpio : 0);
55	return 0;
56}
57
58static int bcma_gpio_request(struct gpio_chip *chip, unsigned gpio)
59{
60	struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
61
62	bcma_chipco_gpio_control(cc, 1 << gpio, 0);
63	/* clear pulldown */
64	bcma_chipco_gpio_pulldown(cc, 1 << gpio, 0);
65	/* Set pullup */
66	bcma_chipco_gpio_pullup(cc, 1 << gpio, 1 << gpio);
67
68	return 0;
69}
70
71static void bcma_gpio_free(struct gpio_chip *chip, unsigned gpio)
72{
73	struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
74
75	/* clear pullup */
76	bcma_chipco_gpio_pullup(cc, 1 << gpio, 0);
77}
78
79#if IS_BUILTIN(CONFIG_BCM47XX) || IS_BUILTIN(CONFIG_ARCH_BCM_5301X)
80
81static void bcma_gpio_irq_unmask(struct irq_data *d)
82{
83	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
84	struct bcma_drv_cc *cc = bcma_gpio_get_cc(gc);
85	int gpio = irqd_to_hwirq(d);
86	u32 val = bcma_chipco_gpio_in(cc, BIT(gpio));
87
88	bcma_chipco_gpio_polarity(cc, BIT(gpio), val);
89	bcma_chipco_gpio_intmask(cc, BIT(gpio), BIT(gpio));
90}
91
92static void bcma_gpio_irq_mask(struct irq_data *d)
93{
94	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
95	struct bcma_drv_cc *cc = bcma_gpio_get_cc(gc);
96	int gpio = irqd_to_hwirq(d);
97
98	bcma_chipco_gpio_intmask(cc, BIT(gpio), 0);
99}
100
101static struct irq_chip bcma_gpio_irq_chip = {
102	.name		= "BCMA-GPIO",
103	.irq_mask	= bcma_gpio_irq_mask,
104	.irq_unmask	= bcma_gpio_irq_unmask,
105};
106
107static irqreturn_t bcma_gpio_irq_handler(int irq, void *dev_id)
108{
109	struct bcma_drv_cc *cc = dev_id;
110	struct gpio_chip *gc = &cc->gpio;
111	u32 val = bcma_cc_read32(cc, BCMA_CC_GPIOIN);
112	u32 mask = bcma_cc_read32(cc, BCMA_CC_GPIOIRQ);
113	u32 pol = bcma_cc_read32(cc, BCMA_CC_GPIOPOL);
114	unsigned long irqs = (val ^ pol) & mask;
115	int gpio;
116
117	if (!irqs)
118		return IRQ_NONE;
119
120	for_each_set_bit(gpio, &irqs, gc->ngpio)
121		generic_handle_irq(irq_find_mapping(gc->irqdomain, gpio));
122	bcma_chipco_gpio_polarity(cc, irqs, val & irqs);
123
124	return IRQ_HANDLED;
125}
126
127static int bcma_gpio_irq_init(struct bcma_drv_cc *cc)
128{
129	struct gpio_chip *chip = &cc->gpio;
130	int hwirq, err;
131
132	if (cc->core->bus->hosttype != BCMA_HOSTTYPE_SOC)
133		return 0;
134
135	hwirq = bcma_core_irq(cc->core, 0);
136	err = request_irq(hwirq, bcma_gpio_irq_handler, IRQF_SHARED, "gpio",
137			  cc);
138	if (err)
139		return err;
140
141	bcma_chipco_gpio_intmask(cc, ~0, 0);
142	bcma_cc_set32(cc, BCMA_CC_IRQMASK, BCMA_CC_IRQ_GPIO);
143
144	err =  gpiochip_irqchip_add(chip,
145				    &bcma_gpio_irq_chip,
146				    0,
147				    handle_simple_irq,
148				    IRQ_TYPE_NONE);
149	if (err) {
150		free_irq(hwirq, cc);
151		return err;
152	}
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->owner		= THIS_MODULE;
191	chip->dev		= bcma_bus_get_host_dev(bus);
192#if IS_BUILTIN(CONFIG_OF)
193	if (cc->core->bus->hosttype == BCMA_HOSTTYPE_SOC)
194		chip->of_node	= cc->core->dev.of_node;
195#endif
196	switch (bus->chipinfo.id) {
197	case BCMA_CHIP_ID_BCM4707:
198	case BCMA_CHIP_ID_BCM5357:
199	case BCMA_CHIP_ID_BCM53572:
200		chip->ngpio	= 32;
201		break;
202	default:
203		chip->ngpio	= 16;
204	}
205
206	/*
207	 * Register SoC GPIO devices with absolute GPIO pin base.
208	 * On MIPS, we don't have Device Tree and we can't use relative (per chip)
209	 * GPIO numbers.
210	 * On some ARM devices, user space may want to access some system GPIO
211	 * pins directly, which is easier to do with a predictable GPIO base.
212	 */
213	if (IS_BUILTIN(CONFIG_BCM47XX) ||
214	    cc->core->bus->hosttype == BCMA_HOSTTYPE_SOC)
215		chip->base		= bus->num * BCMA_GPIO_MAX_PINS;
216	else
217		chip->base		= -1;
218
219	err = gpiochip_add(chip);
220	if (err)
221		return err;
222
223	err = bcma_gpio_irq_init(cc);
224	if (err) {
225		gpiochip_remove(chip);
226		return err;
227	}
228
229	return 0;
230}
231
232int bcma_gpio_unregister(struct bcma_drv_cc *cc)
233{
234	bcma_gpio_irq_exit(cc);
235	gpiochip_remove(&cc->gpio);
236	return 0;
237}
238