driver_gpio.c

  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 int bcma_gpio_set_value(struct gpio_chip *chip, unsigned int 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	return 0;
 37}
 38
 39static int bcma_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
 40{
 41	struct bcma_drv_cc *cc = gpiochip_get_data(chip);
 42
 43	bcma_chipco_gpio_outen(cc, 1 << gpio, 0);
 44	return 0;
 45}
 46
 47static int bcma_gpio_direction_output(struct gpio_chip *chip, unsigned gpio,
 48				      int value)
 49{
 50	struct bcma_drv_cc *cc = gpiochip_get_data(chip);
 51
 52	bcma_chipco_gpio_outen(cc, 1 << gpio, 1 << gpio);
 53	bcma_chipco_gpio_out(cc, 1 << gpio, value ? 1 << gpio : 0);
 54	return 0;
 55}
 56
 57static int bcma_gpio_request(struct gpio_chip *chip, unsigned gpio)
 58{
 59	struct bcma_drv_cc *cc = gpiochip_get_data(chip);
 60
 61	bcma_chipco_gpio_control(cc, 1 << gpio, 0);
 62	/* clear pulldown */
 63	bcma_chipco_gpio_pulldown(cc, 1 << gpio, 0);
 64	/* Set pullup */
 65	bcma_chipco_gpio_pullup(cc, 1 << gpio, 1 << gpio);
 66
 67	return 0;
 68}
 69
 70static void bcma_gpio_free(struct gpio_chip *chip, unsigned gpio)
 71{
 72	struct bcma_drv_cc *cc = gpiochip_get_data(chip);
 73
 74	/* clear pullup */
 75	bcma_chipco_gpio_pullup(cc, 1 << gpio, 0);
 76}
 77
 78#if IS_BUILTIN(CONFIG_BCM47XX) || IS_BUILTIN(CONFIG_ARCH_BCM_5301X)
 79
 80static void bcma_gpio_irq_unmask(struct irq_data *d)
 81{
 82	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 83	struct bcma_drv_cc *cc = gpiochip_get_data(gc);
 84	int gpio = irqd_to_hwirq(d);
 85	u32 val = bcma_chipco_gpio_in(cc, BIT(gpio));
 86
 87	gpiochip_enable_irq(gc, gpio);
 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 = gpiochip_get_data(gc);
 96	int gpio = irqd_to_hwirq(d);
 97
 98	bcma_chipco_gpio_intmask(cc, BIT(gpio), 0);
 99	gpiochip_disable_irq(gc, gpio);
100}
101
102static const struct irq_chip bcma_gpio_irq_chip = {
103	.name		= "BCMA-GPIO",
104	.irq_mask	= bcma_gpio_irq_mask,
105	.irq_unmask	= bcma_gpio_irq_unmask,
106	.flags		= IRQCHIP_IMMUTABLE,
107	GPIOCHIP_IRQ_RESOURCE_HELPERS,
108};
109
110static irqreturn_t bcma_gpio_irq_handler(int irq, void *dev_id)
111{
112	struct bcma_drv_cc *cc = dev_id;
113	struct gpio_chip *gc = &cc->gpio;
114	u32 val = bcma_cc_read32(cc, BCMA_CC_GPIOIN);
115	u32 mask = bcma_cc_read32(cc, BCMA_CC_GPIOIRQ);
116	u32 pol = bcma_cc_read32(cc, BCMA_CC_GPIOPOL);
117	unsigned long irqs = (val ^ pol) & mask;
118	int gpio;
119
120	if (!irqs)
121		return IRQ_NONE;
122
123	for_each_set_bit(gpio, &irqs, gc->ngpio)
124		generic_handle_domain_irq_safe(gc->irq.domain, gpio);
125	bcma_chipco_gpio_polarity(cc, irqs, val & irqs);
126
127	return IRQ_HANDLED;
128}
129
130static int bcma_gpio_irq_init(struct bcma_drv_cc *cc)
131{
132	struct gpio_chip *chip = &cc->gpio;
133	struct gpio_irq_chip *girq = &chip->irq;
134	int hwirq, err;
135
136	if (cc->core->bus->hosttype != BCMA_HOSTTYPE_SOC)
137		return 0;
138
139	hwirq = bcma_core_irq(cc->core, 0);
140	err = request_irq(hwirq, bcma_gpio_irq_handler, IRQF_SHARED, "gpio",
141			  cc);
142	if (err)
143		return err;
144
145	bcma_chipco_gpio_intmask(cc, ~0, 0);
146	bcma_cc_set32(cc, BCMA_CC_IRQMASK, BCMA_CC_IRQ_GPIO);
147
148	gpio_irq_chip_set_chip(girq, &bcma_gpio_irq_chip);
149	/* This will let us handle the parent IRQ in the driver */
150	girq->parent_handler = NULL;
151	girq->num_parents = 0;
152	girq->parents = NULL;
153	girq->default_type = IRQ_TYPE_NONE;
154	girq->handler = handle_simple_irq;
155
156	return 0;
157}
158
159static void bcma_gpio_irq_exit(struct bcma_drv_cc *cc)
160{
161	if (cc->core->bus->hosttype != BCMA_HOSTTYPE_SOC)
162		return;
163
164	bcma_cc_mask32(cc, BCMA_CC_IRQMASK, ~BCMA_CC_IRQ_GPIO);
165	free_irq(bcma_core_irq(cc->core, 0), cc);
166}
167#else
168static int bcma_gpio_irq_init(struct bcma_drv_cc *cc)
169{
170	return 0;
171}
172
173static void bcma_gpio_irq_exit(struct bcma_drv_cc *cc)
174{
175}
176#endif
177
178int bcma_gpio_init(struct bcma_drv_cc *cc)
179{
180	struct bcma_bus *bus = cc->core->bus;
181	struct gpio_chip *chip = &cc->gpio;
182	int err;
183
184	chip->label		= "bcma_gpio";
185	chip->owner		= THIS_MODULE;
186	chip->request		= bcma_gpio_request;
187	chip->free		= bcma_gpio_free;
188	chip->get		= bcma_gpio_get_value;
189	chip->set		= bcma_gpio_set_value;
190	chip->direction_input	= bcma_gpio_direction_input;
191	chip->direction_output	= bcma_gpio_direction_output;
192	chip->parent		= bus->dev;
193	chip->fwnode		= dev_fwnode(&cc->core->dev);
194
195	switch (bus->chipinfo.id) {
196	case BCMA_CHIP_ID_BCM4707:
197	case BCMA_CHIP_ID_BCM5357:
198	case BCMA_CHIP_ID_BCM53572:
199	case BCMA_CHIP_ID_BCM53573:
200	case BCMA_CHIP_ID_BCM47094:
201		chip->ngpio	= 32;
202		break;
203	default:
204		chip->ngpio	= 16;
205	}
206
207	/*
208	 * Register SoC GPIO devices with absolute GPIO pin base.
209	 * On MIPS, we don't have Device Tree and we can't use relative (per chip)
210	 * GPIO numbers.
211	 * On some ARM devices, user space may want to access some system GPIO
212	 * pins directly, which is easier to do with a predictable GPIO base.
213	 */
214	if (IS_BUILTIN(CONFIG_BCM47XX) ||
215	    cc->core->bus->hosttype == BCMA_HOSTTYPE_SOC)
216		chip->base		= bus->num * BCMA_GPIO_MAX_PINS;
217	else
218		chip->base		= -1;
219
220	err = bcma_gpio_irq_init(cc);
221	if (err)
222		return err;
223
224	err = gpiochip_add_data(chip, cc);
225	if (err) {
226		bcma_gpio_irq_exit(cc);
227		return err;
228	}
229
230	return 0;
231}
232
233int bcma_gpio_unregister(struct bcma_drv_cc *cc)
234{
235	bcma_gpio_irq_exit(cc);
236	gpiochip_remove(&cc->gpio);
237	return 0;
238}