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.h>
12#include <linux/irq.h>
13#include <linux/interrupt.h>
14#include <linux/irqdomain.h>
15#include <linux/export.h>
16#include <linux/bcma/bcma.h>
17
18#include "bcma_private.h"
19
20#define BCMA_GPIO_MAX_PINS	32
21
22static inline struct bcma_drv_cc *bcma_gpio_get_cc(struct gpio_chip *chip)
23{
24	return container_of(chip, struct bcma_drv_cc, gpio);
25}
26
27static int bcma_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
28{
29	struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
30
31	return !!bcma_chipco_gpio_in(cc, 1 << gpio);
32}
33
34static void bcma_gpio_set_value(struct gpio_chip *chip, unsigned gpio,
35				int value)
36{
37	struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
38
39	bcma_chipco_gpio_out(cc, 1 << gpio, value ? 1 << gpio : 0);
40}
41
42static int bcma_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
43{
44	struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
45
46	bcma_chipco_gpio_outen(cc, 1 << gpio, 0);
47	return 0;
48}
49
50static int bcma_gpio_direction_output(struct gpio_chip *chip, unsigned gpio,
51				      int value)
52{
53	struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
54
55	bcma_chipco_gpio_outen(cc, 1 << gpio, 1 << gpio);
56	bcma_chipco_gpio_out(cc, 1 << gpio, value ? 1 << gpio : 0);
57	return 0;
58}
59
60static int bcma_gpio_request(struct gpio_chip *chip, unsigned gpio)
61{
62	struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
63
64	bcma_chipco_gpio_control(cc, 1 << gpio, 0);
65	/* clear pulldown */
66	bcma_chipco_gpio_pulldown(cc, 1 << gpio, 0);
67	/* Set pullup */
68	bcma_chipco_gpio_pullup(cc, 1 << gpio, 1 << gpio);
69
70	return 0;
71}
72
73static void bcma_gpio_free(struct gpio_chip *chip, unsigned gpio)
74{
75	struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
76
77	/* clear pullup */
78	bcma_chipco_gpio_pullup(cc, 1 << gpio, 0);
79}
80
81#if IS_BUILTIN(CONFIG_BCM47XX) || IS_BUILTIN(CONFIG_ARCH_BCM_5301X)
82static int bcma_gpio_to_irq(struct gpio_chip *chip, unsigned gpio)
83{
84	struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
85
86	if (cc->core->bus->hosttype == BCMA_HOSTTYPE_SOC)
87		return irq_find_mapping(cc->irq_domain, gpio);
88	else
89		return -EINVAL;
90}
91
92static void bcma_gpio_irq_unmask(struct irq_data *d)
93{
94	struct bcma_drv_cc *cc = irq_data_get_irq_chip_data(d);
95	int gpio = irqd_to_hwirq(d);
96	u32 val = bcma_chipco_gpio_in(cc, BIT(gpio));
97
98	bcma_chipco_gpio_polarity(cc, BIT(gpio), val);
99	bcma_chipco_gpio_intmask(cc, BIT(gpio), BIT(gpio));
100}
101
102static void bcma_gpio_irq_mask(struct irq_data *d)
103{
104	struct bcma_drv_cc *cc = irq_data_get_irq_chip_data(d);
105	int gpio = irqd_to_hwirq(d);
106
107	bcma_chipco_gpio_intmask(cc, BIT(gpio), 0);
108}
109
110static struct irq_chip bcma_gpio_irq_chip = {
111	.name		= "BCMA-GPIO",
112	.irq_mask	= bcma_gpio_irq_mask,
113	.irq_unmask	= bcma_gpio_irq_unmask,
114};
115
116static irqreturn_t bcma_gpio_irq_handler(int irq, void *dev_id)
117{
118	struct bcma_drv_cc *cc = dev_id;
119	u32 val = bcma_cc_read32(cc, BCMA_CC_GPIOIN);
120	u32 mask = bcma_cc_read32(cc, BCMA_CC_GPIOIRQ);
121	u32 pol = bcma_cc_read32(cc, BCMA_CC_GPIOPOL);
122	unsigned long irqs = (val ^ pol) & mask;
123	int gpio;
124
125	if (!irqs)
126		return IRQ_NONE;
127
128	for_each_set_bit(gpio, &irqs, cc->gpio.ngpio)
129		generic_handle_irq(bcma_gpio_to_irq(&cc->gpio, gpio));
130	bcma_chipco_gpio_polarity(cc, irqs, val & irqs);
131
132	return IRQ_HANDLED;
133}
134
135static int bcma_gpio_irq_domain_init(struct bcma_drv_cc *cc)
136{
137	struct gpio_chip *chip = &cc->gpio;
138	int gpio, hwirq, err;
139
140	if (cc->core->bus->hosttype != BCMA_HOSTTYPE_SOC)
141		return 0;
142
143	cc->irq_domain = irq_domain_add_linear(NULL, chip->ngpio,
144					       &irq_domain_simple_ops, cc);
145	if (!cc->irq_domain) {
146		err = -ENODEV;
147		goto err_irq_domain;
148	}
149	for (gpio = 0; gpio < chip->ngpio; gpio++) {
150		int irq = irq_create_mapping(cc->irq_domain, gpio);
151
152		irq_set_chip_data(irq, cc);
153		irq_set_chip_and_handler(irq, &bcma_gpio_irq_chip,
154					 handle_simple_irq);
155	}
156
157	hwirq = bcma_core_irq(cc->core, 0);
158	err = request_irq(hwirq, bcma_gpio_irq_handler, IRQF_SHARED, "gpio",
159			  cc);
160	if (err)
161		goto err_req_irq;
162
163	bcma_chipco_gpio_intmask(cc, ~0, 0);
164	bcma_cc_set32(cc, BCMA_CC_IRQMASK, BCMA_CC_IRQ_GPIO);
165
166	return 0;
167
168err_req_irq:
169	for (gpio = 0; gpio < chip->ngpio; gpio++) {
170		int irq = irq_find_mapping(cc->irq_domain, gpio);
171
172		irq_dispose_mapping(irq);
173	}
174	irq_domain_remove(cc->irq_domain);
175err_irq_domain:
176	return err;
177}
178
179static void bcma_gpio_irq_domain_exit(struct bcma_drv_cc *cc)
180{
181	struct gpio_chip *chip = &cc->gpio;
182	int gpio;
183
184	if (cc->core->bus->hosttype != BCMA_HOSTTYPE_SOC)
185		return;
186
187	bcma_cc_mask32(cc, BCMA_CC_IRQMASK, ~BCMA_CC_IRQ_GPIO);
188	free_irq(bcma_core_irq(cc->core, 0), cc);
189	for (gpio = 0; gpio < chip->ngpio; gpio++) {
190		int irq = irq_find_mapping(cc->irq_domain, gpio);
191
192		irq_dispose_mapping(irq);
193	}
194	irq_domain_remove(cc->irq_domain);
195}
196#else
197static int bcma_gpio_irq_domain_init(struct bcma_drv_cc *cc)
198{
199	return 0;
200}
201
202static void bcma_gpio_irq_domain_exit(struct bcma_drv_cc *cc)
203{
204}
205#endif
206
207int bcma_gpio_init(struct bcma_drv_cc *cc)
208{
209	struct bcma_bus *bus = cc->core->bus;
210	struct gpio_chip *chip = &cc->gpio;
211	int err;
212
213	chip->label		= "bcma_gpio";
214	chip->owner		= THIS_MODULE;
215	chip->request		= bcma_gpio_request;
216	chip->free		= bcma_gpio_free;
217	chip->get		= bcma_gpio_get_value;
218	chip->set		= bcma_gpio_set_value;
219	chip->direction_input	= bcma_gpio_direction_input;
220	chip->direction_output	= bcma_gpio_direction_output;
221#if IS_BUILTIN(CONFIG_BCM47XX) || IS_BUILTIN(CONFIG_ARCH_BCM_5301X)
222	chip->to_irq		= bcma_gpio_to_irq;
223#endif
224#if IS_BUILTIN(CONFIG_OF)
225	if (cc->core->bus->hosttype == BCMA_HOSTTYPE_SOC)
226		chip->of_node	= cc->core->dev.of_node;
227#endif
228	switch (bus->chipinfo.id) {
229	case BCMA_CHIP_ID_BCM5357:
230	case BCMA_CHIP_ID_BCM53572:
231		chip->ngpio	= 32;
232		break;
233	default:
234		chip->ngpio	= 16;
235	}
236
237	/*
238	 * On MIPS we register GPIO devices (LEDs, buttons) using absolute GPIO
239	 * pin numbers. We don't have Device Tree there and we can't really use
240	 * relative (per chip) numbers.
241	 * So let's use predictable base for BCM47XX and "random" for all other.
242	 */
243#if IS_BUILTIN(CONFIG_BCM47XX)
244	chip->base		= bus->num * BCMA_GPIO_MAX_PINS;
245#else
246	chip->base		= -1;
247#endif
248
249	err = bcma_gpio_irq_domain_init(cc);
250	if (err)
251		return err;
252
253	err = gpiochip_add(chip);
254	if (err) {
255		bcma_gpio_irq_domain_exit(cc);
256		return err;
257	}
258
259	return 0;
260}
261
262int bcma_gpio_unregister(struct bcma_drv_cc *cc)
263{
264	bcma_gpio_irq_domain_exit(cc);
265	gpiochip_remove(&cc->gpio);
266	return 0;
267}
268