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/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
  20 static 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
  27 static 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
  35 static 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
  43 static 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
  53 static 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
  66 static 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
  76 static 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
  87 static 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
  96 static 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
 102 static 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
 122 static 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
 151 static 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
 160 static int bcma_gpio_irq_init(struct bcma_drv_cc *cc)
 161 {
 162         return 0;
 163 }
 164
 165 static void bcma_gpio_irq_exit(struct bcma_drv_cc *cc)
 166 {
 167 }
 168 #endif
 169
 170 int 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
 227 int bcma_gpio_unregister(struct bcma_drv_cc *cc)
 228 {
 229         bcma_gpio_irq_exit(cc);
 230         gpiochip_remove(&cc->gpio);
 231         return 0;
 232 }