drivers/bcma/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.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
  22 static 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
  27 static 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
  34 static 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
  42 static 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
  50 static 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
  60 static 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
  73 static 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)
  82 static 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
  92 static 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
 102 static 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
 110 static 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
 116 static 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
 135 static 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
 168 err_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);
 175 err_irq_domain:
 176         return err;
 177 }
 178
 179 static 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
 197 static int bcma_gpio_irq_domain_init(struct bcma_drv_cc *cc)
 198 {
 199         return 0;
 200 }
 201
 202 static void bcma_gpio_irq_domain_exit(struct bcma_drv_cc *cc)
 203 {
 204 }
 205 #endif
 206
 207 int 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_BCM4707:
 230         case BCMA_CHIP_ID_BCM5357:
 231         case BCMA_CHIP_ID_BCM53572:
 232                 chip->ngpio     = 32;
 233                 break;
 234         default:
 235                 chip->ngpio     = 16;
 236         }
 237
 238         /*
 239          * Register SoC GPIO devices with absolute GPIO pin base.
 240          * On MIPS, we don't have Device Tree and we can't use relative (per chip)
 241          * GPIO numbers.
 242          * On some ARM devices, user space may want to access some system GPIO
 243          * pins directly, which is easier to do with a predictable GPIO base.
 244          */
 245         if (IS_BUILTIN(CONFIG_BCM47XX) ||
 246             cc->core->bus->hosttype == BCMA_HOSTTYPE_SOC)
 247                 chip->base              = bus->num * BCMA_GPIO_MAX_PINS;
 248         else
 249                 chip->base              = -1;
 250
 251         err = bcma_gpio_irq_domain_init(cc);
 252         if (err)
 253                 return err;
 254
 255         err = gpiochip_add(chip);
 256         if (err) {
 257                 bcma_gpio_irq_domain_exit(cc);
 258                 return err;
 259         }
 260
 261         return 0;
 262 }
 263
 264 int bcma_gpio_unregister(struct bcma_drv_cc *cc)
 265 {
 266         bcma_gpio_irq_domain_exit(cc);
 267         gpiochip_remove(&cc->gpio);
 268         return 0;
 269 }