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 static inline struct bcma_drv_cc *bcma_gpio_get_cc(struct gpio_chip *chip)
  21 {
  22         return container_of(chip, struct bcma_drv_cc, gpio);
  23 }
  24
  25 static int bcma_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
  26 {
  27         struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
  28
  29         return !!bcma_chipco_gpio_in(cc, 1 << gpio);
  30 }
  31
  32 static void bcma_gpio_set_value(struct gpio_chip *chip, unsigned gpio,
  33                                 int value)
  34 {
  35         struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
  36
  37         bcma_chipco_gpio_out(cc, 1 << gpio, value ? 1 << gpio : 0);
  38 }
  39
  40 static int bcma_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
  41 {
  42         struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
  43
  44         bcma_chipco_gpio_outen(cc, 1 << gpio, 0);
  45         return 0;
  46 }
  47
  48 static int bcma_gpio_direction_output(struct gpio_chip *chip, unsigned gpio,
  49                                       int value)
  50 {
  51         struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
  52
  53         bcma_chipco_gpio_outen(cc, 1 << gpio, 1 << gpio);
  54         bcma_chipco_gpio_out(cc, 1 << gpio, value ? 1 << gpio : 0);
  55         return 0;
  56 }
  57
  58 static int bcma_gpio_request(struct gpio_chip *chip, unsigned gpio)
  59 {
  60         struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
  61
  62         bcma_chipco_gpio_control(cc, 1 << gpio, 0);
  63         /* clear pulldown */
  64         bcma_chipco_gpio_pulldown(cc, 1 << gpio, 0);
  65         /* Set pullup */
  66         bcma_chipco_gpio_pullup(cc, 1 << gpio, 1 << gpio);
  67
  68         return 0;
  69 }
  70
  71 static void bcma_gpio_free(struct gpio_chip *chip, unsigned gpio)
  72 {
  73         struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
  74
  75         /* clear pullup */
  76         bcma_chipco_gpio_pullup(cc, 1 << gpio, 0);
  77 }
  78
  79 #if IS_BUILTIN(CONFIG_BCMA_HOST_SOC)
  80 static int bcma_gpio_to_irq(struct gpio_chip *chip, unsigned gpio)
  81 {
  82         struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
  83
  84         if (cc->core->bus->hosttype == BCMA_HOSTTYPE_SOC)
  85                 return irq_find_mapping(cc->irq_domain, gpio);
  86         else
  87                 return -EINVAL;
  88 }
  89
  90 static void bcma_gpio_irq_unmask(struct irq_data *d)
  91 {
  92         struct bcma_drv_cc *cc = irq_data_get_irq_chip_data(d);
  93         int gpio = irqd_to_hwirq(d);
  94         u32 val = bcma_chipco_gpio_in(cc, BIT(gpio));
  95
  96         bcma_chipco_gpio_polarity(cc, BIT(gpio), val);
  97         bcma_chipco_gpio_intmask(cc, BIT(gpio), BIT(gpio));
  98 }
  99
 100 static void bcma_gpio_irq_mask(struct irq_data *d)
 101 {
 102         struct bcma_drv_cc *cc = irq_data_get_irq_chip_data(d);
 103         int gpio = irqd_to_hwirq(d);
 104
 105         bcma_chipco_gpio_intmask(cc, BIT(gpio), 0);
 106 }
 107
 108 static struct irq_chip bcma_gpio_irq_chip = {
 109         .name           = "BCMA-GPIO",
 110         .irq_mask       = bcma_gpio_irq_mask,
 111         .irq_unmask     = bcma_gpio_irq_unmask,
 112 };
 113
 114 static irqreturn_t bcma_gpio_irq_handler(int irq, void *dev_id)
 115 {
 116         struct bcma_drv_cc *cc = dev_id;
 117         u32 val = bcma_cc_read32(cc, BCMA_CC_GPIOIN);
 118         u32 mask = bcma_cc_read32(cc, BCMA_CC_GPIOIRQ);
 119         u32 pol = bcma_cc_read32(cc, BCMA_CC_GPIOPOL);
 120         unsigned long irqs = (val ^ pol) & mask;
 121         int gpio;
 122
 123         if (!irqs)
 124                 return IRQ_NONE;
 125
 126         for_each_set_bit(gpio, &irqs, cc->gpio.ngpio)
 127                 generic_handle_irq(bcma_gpio_to_irq(&cc->gpio, gpio));
 128         bcma_chipco_gpio_polarity(cc, irqs, val & irqs);
 129
 130         return IRQ_HANDLED;
 131 }
 132
 133 static int bcma_gpio_irq_domain_init(struct bcma_drv_cc *cc)
 134 {
 135         struct gpio_chip *chip = &cc->gpio;
 136         int gpio, hwirq, err;
 137
 138         if (cc->core->bus->hosttype != BCMA_HOSTTYPE_SOC)
 139                 return 0;
 140
 141         cc->irq_domain = irq_domain_add_linear(NULL, chip->ngpio,
 142                                                &irq_domain_simple_ops, cc);
 143         if (!cc->irq_domain) {
 144                 err = -ENODEV;
 145                 goto err_irq_domain;
 146         }
 147         for (gpio = 0; gpio < chip->ngpio; gpio++) {
 148                 int irq = irq_create_mapping(cc->irq_domain, gpio);
 149
 150                 irq_set_chip_data(irq, cc);
 151                 irq_set_chip_and_handler(irq, &bcma_gpio_irq_chip,
 152                                          handle_simple_irq);
 153         }
 154
 155         hwirq = bcma_core_irq(cc->core);
 156         err = request_irq(hwirq, bcma_gpio_irq_handler, IRQF_SHARED, "gpio",
 157                           cc);
 158         if (err)
 159                 goto err_req_irq;
 160
 161         bcma_chipco_gpio_intmask(cc, ~0, 0);
 162         bcma_cc_set32(cc, BCMA_CC_IRQMASK, BCMA_CC_IRQ_GPIO);
 163
 164         return 0;
 165
 166 err_req_irq:
 167         for (gpio = 0; gpio < chip->ngpio; gpio++) {
 168                 int irq = irq_find_mapping(cc->irq_domain, gpio);
 169
 170                 irq_dispose_mapping(irq);
 171         }
 172         irq_domain_remove(cc->irq_domain);
 173 err_irq_domain:
 174         return err;
 175 }
 176
 177 static void bcma_gpio_irq_domain_exit(struct bcma_drv_cc *cc)
 178 {
 179         struct gpio_chip *chip = &cc->gpio;
 180         int gpio;
 181
 182         if (cc->core->bus->hosttype != BCMA_HOSTTYPE_SOC)
 183                 return;
 184
 185         bcma_cc_mask32(cc, BCMA_CC_IRQMASK, ~BCMA_CC_IRQ_GPIO);
 186         free_irq(bcma_core_irq(cc->core), cc);
 187         for (gpio = 0; gpio < chip->ngpio; gpio++) {
 188                 int irq = irq_find_mapping(cc->irq_domain, gpio);
 189
 190                 irq_dispose_mapping(irq);
 191         }
 192         irq_domain_remove(cc->irq_domain);
 193 }
 194 #else
 195 static int bcma_gpio_irq_domain_init(struct bcma_drv_cc *cc)
 196 {
 197         return 0;
 198 }
 199
 200 static void bcma_gpio_irq_domain_exit(struct bcma_drv_cc *cc)
 201 {
 202 }
 203 #endif
 204
 205 int bcma_gpio_init(struct bcma_drv_cc *cc)
 206 {
 207         struct gpio_chip *chip = &cc->gpio;
 208         int err;
 209
 210         chip->label             = "bcma_gpio";
 211         chip->owner             = THIS_MODULE;
 212         chip->request           = bcma_gpio_request;
 213         chip->free              = bcma_gpio_free;
 214         chip->get               = bcma_gpio_get_value;
 215         chip->set               = bcma_gpio_set_value;
 216         chip->direction_input   = bcma_gpio_direction_input;
 217         chip->direction_output  = bcma_gpio_direction_output;
 218 #if IS_BUILTIN(CONFIG_BCMA_HOST_SOC)
 219         chip->to_irq            = bcma_gpio_to_irq;
 220 #endif
 221         chip->ngpio             = 16;
 222         /* There is just one SoC in one device and its GPIO addresses should be
 223          * deterministic to address them more easily. The other buses could get
 224          * a random base number. */
 225         if (cc->core->bus->hosttype == BCMA_HOSTTYPE_SOC)
 226                 chip->base              = 0;
 227         else
 228                 chip->base              = -1;
 229
 230         err = bcma_gpio_irq_domain_init(cc);
 231         if (err)
 232                 return err;
 233
 234         err = gpiochip_add(chip);
 235         if (err) {
 236                 bcma_gpio_irq_domain_exit(cc);
 237                 return err;
 238         }
 239
 240         return 0;
 241 }
 242
 243 int bcma_gpio_unregister(struct bcma_drv_cc *cc)
 244 {
 245         bcma_gpio_irq_domain_exit(cc);
 246         return gpiochip_remove(&cc->gpio);
 247 }