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