drivers/gpio/gpio-ftgpio010.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Faraday Technolog FTGPIO010 gpiochip and interrupt routines
   4  * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
   5  *
   6  * Based on arch/arm/mach-gemini/gpio.c:
   7  * Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
   8  *
   9  * Based on plat-mxc/gpio.c:
  10  * MXC GPIO support. (c) 2008 Daniel Mack <daniel@caiaq.de>
  11  * Copyright 2008 Juergen Beisert, kernel@pengutronix.de
  12  */
  13 #include <linux/gpio/driver.h>
  14 #include <linux/io.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/of_gpio.h>
  18 #include <linux/bitops.h>
  19
  20 /* GPIO registers definition */
  21 #define GPIO_DATA_OUT           0x00
  22 #define GPIO_DATA_IN            0x04
  23 #define GPIO_DIR                0x08
  24 #define GPIO_DATA_SET           0x10
  25 #define GPIO_DATA_CLR           0x14
  26 #define GPIO_PULL_EN            0x18
  27 #define GPIO_PULL_TYPE          0x1C
  28 #define GPIO_INT_EN             0x20
  29 #define GPIO_INT_STAT           0x24
  30 #define GPIO_INT_MASK           0x2C
  31 #define GPIO_INT_CLR            0x30
  32 #define GPIO_INT_TYPE           0x34
  33 #define GPIO_INT_BOTH_EDGE      0x38
  34 #define GPIO_INT_LEVEL          0x3C
  35 #define GPIO_DEBOUNCE_EN        0x40
  36 #define GPIO_DEBOUNCE_PRESCALE  0x44
  37
  38 /**
  39  * struct ftgpio_gpio - Gemini GPIO state container
  40  * @dev: containing device for this instance
  41  * @gc: gpiochip for this instance
  42  */
  43 struct ftgpio_gpio {
  44         struct device *dev;
  45         struct gpio_chip gc;
  46         void __iomem *base;
  47 };
  48
  49 static void ftgpio_gpio_ack_irq(struct irq_data *d)
  50 {
  51         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
  52         struct ftgpio_gpio *g = gpiochip_get_data(gc);
  53
  54         writel(BIT(irqd_to_hwirq(d)), g->base + GPIO_INT_CLR);
  55 }
  56
  57 static void ftgpio_gpio_mask_irq(struct irq_data *d)
  58 {
  59         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
  60         struct ftgpio_gpio *g = gpiochip_get_data(gc);
  61         u32 val;
  62
  63         val = readl(g->base + GPIO_INT_EN);
  64         val &= ~BIT(irqd_to_hwirq(d));
  65         writel(val, g->base + GPIO_INT_EN);
  66 }
  67
  68 static void ftgpio_gpio_unmask_irq(struct irq_data *d)
  69 {
  70         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
  71         struct ftgpio_gpio *g = gpiochip_get_data(gc);
  72         u32 val;
  73
  74         val = readl(g->base + GPIO_INT_EN);
  75         val |= BIT(irqd_to_hwirq(d));
  76         writel(val, g->base + GPIO_INT_EN);
  77 }
  78
  79 static int ftgpio_gpio_set_irq_type(struct irq_data *d, unsigned int type)
  80 {
  81         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
  82         struct ftgpio_gpio *g = gpiochip_get_data(gc);
  83         u32 mask = BIT(irqd_to_hwirq(d));
  84         u32 reg_both, reg_level, reg_type;
  85
  86         reg_type = readl(g->base + GPIO_INT_TYPE);
  87         reg_level = readl(g->base + GPIO_INT_LEVEL);
  88         reg_both = readl(g->base + GPIO_INT_BOTH_EDGE);
  89
  90         switch (type) {
  91         case IRQ_TYPE_EDGE_BOTH:
  92                 irq_set_handler_locked(d, handle_edge_irq);
  93                 reg_type &= ~mask;
  94                 reg_both |= mask;
  95                 break;
  96         case IRQ_TYPE_EDGE_RISING:
  97                 irq_set_handler_locked(d, handle_edge_irq);
  98                 reg_type &= ~mask;
  99                 reg_both &= ~mask;
 100                 reg_level &= ~mask;
 101                 break;
 102         case IRQ_TYPE_EDGE_FALLING:
 103                 irq_set_handler_locked(d, handle_edge_irq);
 104                 reg_type &= ~mask;
 105                 reg_both &= ~mask;
 106                 reg_level |= mask;
 107                 break;
 108         case IRQ_TYPE_LEVEL_HIGH:
 109                 irq_set_handler_locked(d, handle_level_irq);
 110                 reg_type |= mask;
 111                 reg_level &= ~mask;
 112                 break;
 113         case IRQ_TYPE_LEVEL_LOW:
 114                 irq_set_handler_locked(d, handle_level_irq);
 115                 reg_type |= mask;
 116                 reg_level |= mask;
 117                 break;
 118         default:
 119                 irq_set_handler_locked(d, handle_bad_irq);
 120                 return -EINVAL;
 121         }
 122
 123         writel(reg_type, g->base + GPIO_INT_TYPE);
 124         writel(reg_level, g->base + GPIO_INT_LEVEL);
 125         writel(reg_both, g->base + GPIO_INT_BOTH_EDGE);
 126
 127         ftgpio_gpio_ack_irq(d);
 128
 129         return 0;
 130 }
 131
 132 static struct irq_chip ftgpio_gpio_irqchip = {
 133         .name = "FTGPIO010",
 134         .irq_ack = ftgpio_gpio_ack_irq,
 135         .irq_mask = ftgpio_gpio_mask_irq,
 136         .irq_unmask = ftgpio_gpio_unmask_irq,
 137         .irq_set_type = ftgpio_gpio_set_irq_type,
 138 };
 139
 140 static void ftgpio_gpio_irq_handler(struct irq_desc *desc)
 141 {
 142         struct gpio_chip *gc = irq_desc_get_handler_data(desc);
 143         struct ftgpio_gpio *g = gpiochip_get_data(gc);
 144         struct irq_chip *irqchip = irq_desc_get_chip(desc);
 145         int offset;
 146         unsigned long stat;
 147
 148         chained_irq_enter(irqchip, desc);
 149
 150         stat = readl(g->base + GPIO_INT_STAT);
 151         if (stat)
 152                 for_each_set_bit(offset, &stat, gc->ngpio)
 153                         generic_handle_irq(irq_find_mapping(gc->irqdomain,
 154                                                             offset));
 155
 156         chained_irq_exit(irqchip, desc);
 157 }
 158
 159 static int ftgpio_gpio_probe(struct platform_device *pdev)
 160 {
 161         struct device *dev = &pdev->dev;
 162         struct resource *res;
 163         struct ftgpio_gpio *g;
 164         int irq;
 165         int ret;
 166
 167         g = devm_kzalloc(dev, sizeof(*g), GFP_KERNEL);
 168         if (!g)
 169                 return -ENOMEM;
 170
 171         g->dev = dev;
 172
 173         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 174         g->base = devm_ioremap_resource(dev, res);
 175         if (IS_ERR(g->base))
 176                 return PTR_ERR(g->base);
 177
 178         irq = platform_get_irq(pdev, 0);
 179         if (!irq)
 180                 return -EINVAL;
 181
 182         ret = bgpio_init(&g->gc, dev, 4,
 183                          g->base + GPIO_DATA_IN,
 184                          g->base + GPIO_DATA_SET,
 185                          g->base + GPIO_DATA_CLR,
 186                          g->base + GPIO_DIR,
 187                          NULL,
 188                          0);
 189         if (ret) {
 190                 dev_err(dev, "unable to init generic GPIO\n");
 191                 return ret;
 192         }
 193         g->gc.label = "FTGPIO010";
 194         g->gc.base = -1;
 195         g->gc.parent = dev;
 196         g->gc.owner = THIS_MODULE;
 197         /* ngpio is set by bgpio_init() */
 198
 199         ret = devm_gpiochip_add_data(dev, &g->gc, g);
 200         if (ret)
 201                 return ret;
 202
 203         /* Disable, unmask and clear all interrupts */
 204         writel(0x0, g->base + GPIO_INT_EN);
 205         writel(0x0, g->base + GPIO_INT_MASK);
 206         writel(~0x0, g->base + GPIO_INT_CLR);
 207
 208         ret = gpiochip_irqchip_add(&g->gc, &ftgpio_gpio_irqchip,
 209                                    0, handle_bad_irq,
 210                                    IRQ_TYPE_NONE);
 211         if (ret) {
 212                 dev_info(dev, "could not add irqchip\n");
 213                 return ret;
 214         }
 215         gpiochip_set_chained_irqchip(&g->gc, &ftgpio_gpio_irqchip,
 216                                      irq, ftgpio_gpio_irq_handler);
 217
 218         dev_info(dev, "FTGPIO010 @%p registered\n", g->base);
 219
 220         return 0;
 221 }
 222
 223 static const struct of_device_id ftgpio_gpio_of_match[] = {
 224         {
 225                 .compatible = "cortina,gemini-gpio",
 226         },
 227         {
 228                 .compatible = "moxa,moxart-gpio",
 229         },
 230         {
 231                 .compatible = "faraday,ftgpio010",
 232         },
 233         {},
 234 };
 235
 236 static struct platform_driver ftgpio_gpio_driver = {
 237         .driver = {
 238                 .name           = "ftgpio010-gpio",
 239                 .of_match_table = of_match_ptr(ftgpio_gpio_of_match),
 240         },
 241         .probe  = ftgpio_gpio_probe,
 242 };
 243 builtin_platform_driver(ftgpio_gpio_driver);