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
bcma_gpio_get_value(struct gpio_chip * chip,unsigned gpio)22 static 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
bcma_gpio_set_value(struct gpio_chip * chip,unsigned gpio,int value)29 static 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
bcma_gpio_direction_input(struct gpio_chip * chip,unsigned gpio)37 static 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
bcma_gpio_direction_output(struct gpio_chip * chip,unsigned gpio,int value)45 static 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
bcma_gpio_request(struct gpio_chip * chip,unsigned gpio)55 static 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
bcma_gpio_free(struct gpio_chip * chip,unsigned gpio)68 static 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
bcma_gpio_irq_unmask(struct irq_data * d)78 static 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
bcma_gpio_irq_mask(struct irq_data * d)90 static 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
100 static 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
bcma_gpio_irq_handler(int irq,void * dev_id)108 static 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
bcma_gpio_irq_init(struct bcma_drv_cc * cc)128 static 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
bcma_gpio_irq_exit(struct bcma_drv_cc * cc)157 static 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
bcma_gpio_irq_init(struct bcma_drv_cc * cc)166 static int bcma_gpio_irq_init(struct bcma_drv_cc *cc)
167 {
168 return 0;
169 }
170
bcma_gpio_irq_exit(struct bcma_drv_cc * cc)171 static void bcma_gpio_irq_exit(struct bcma_drv_cc *cc)
172 {
173 }
174 #endif
175
bcma_gpio_init(struct bcma_drv_cc * cc)176 int 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
bcma_gpio_unregister(struct bcma_drv_cc * cc)231 int 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