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 } 248